Saturday, August 31, 2019

Manage People Performance Essay

It is important when allocating work to ensure that resources are appropriately allocated and that they are available for use as and when they are needed. When drawing up a plan you need to focus on what you want to achieve, what you can do to achieve it and what might happen while you are moving toward achievement. You must consider what will be done, when and how it will be done and by whom. You need to identify and communicate organisational vision and develop a unified sense of direction. You will need to conduct an environmental scanning/analysis. Identify short a long term goals and make sure they are realistic and achievable. You would need to develop with relevant personnel strategies and plans for goal achievement as well as financial plans. These plans would need to be communicated to stakeholders and then implement these plans. During this process you must set appropriate KRA’s and KPI’s and track, monitor and evaluate the procedure. When allocating work, the competencies and availability of staff must be considered so that work is allotted to those who are best equipped to do it. You must consider employee experience, skills, knowledge, understandings and workloads. You must consider checking their understanding and give support and opportunities to ask questions. When allocating work the goals and objectives must be clearly defined so that employees can put them into action plans and achieve these goals. Managers and leaders must take into consideration, the interests of the staff members, their availability and the likely outcomes of involving specific employees. You must also consider resource management. When planning work and allocating tasks to employees and employee groups teams efficiency, productivity, cost management and outcomes must all be considered. When allocating work and drawing up plans you must consider a project plan as it shows a description of what is to be done, when and by whom and what funds are available. It covers the entire set of tasks that a project requires and allocates the different aspects of the project to the employees who are best equipped to produce the required outputs. It shows the major products, milestones, activities and resources required on the project. It is necessary to develop KRA’s and KPI’s that meet the organisations needs because they include clearly defined and achievable goals. They measure progress during the year in terms of identified targets, manage skills development, identify areas for development, contribute to the company’s wealth creation, obtain feedback that allow a change of direction when needed and promote an environment of self management. They point to what needs to be achieved. They indicate areas of current and ongoing success. It is also necessary to develop and implement performance management systems because they enable management to track, monitor and evaluate work to ensure that it is contributing towards the success of the organisation. To have a code of conduct in an organisation is vital because it has rules outlining responsibilities of proper practices for individuals and the organisation. It contains descriptions of the principles, values, standards, and rules of behaviour that guide the decisions, procedures and systems of an organisation in a way that contributes to the welfare of its key stakeholders and respects the rights of all constituents affected by its operations. A code of conduct provides a guide to staff for appropriate behaviour it will impact on the way they do their work and on the performance standards expected of the employees. Regularly monitoring and evaluating the work of employees enables the organisations manager to maintain current knowledge of what is happening, to pinpoint problem areas and to solve problems before they become destructive. Monitoring and evaluating will help achieve the intended outcomes, goals and objectives. Giving feedback and reinforcement to employees and acknowledging good work should be a continuous process. Feedback is the information that is given to people to let them know what they are doing well and what needs to improve. It also lets employees know that their efforts have been noticed. Acknowledging reinforces good work practice/behaviour and encourages us in continuing improvement. It acts as a source of recognition for the contribution made by the employees. Employees whose contribution to improvement processes and organisational success is recognised will be motivated to continue improving and you will have created higher levels of enthusiasm. It is important to acknowledge employees efforts and give feedback because employees who feel ignored and exploited will stop caring about their performance levels and quality. The employee will start underperforming, give poor customer service and relationships in the workplace will become strained. Giving effective feedback, reinforcement and acknowledgment will result in learning, improved competence, observable behavioural change and motivation. It will also make the employee feel valued and encourage good work. It is necessary to have systems in place to manage poor performance because they will help monitor, evaluate and keep track of the performance. Performance issues are most easily addressed and resolved when they are at a low level of difficulty and of short duration. Having systems in place will help you see what is doing well and what isn’t and you will be able to change, address and fix it. Problems that are not addressed might go underground, to represent at a later time at a higher level of disruption and significance. Having systems that manage poor performance in place will lead to improvement in performances. It is necessary to understand the organisations termination policy and the legislation to which it relates because unfair termination or dismissal can lead to consequences of dismissal under unfair dismissal laws. Employees can claim that their dismissal was harsh, unjust or unreasonable and unfair and file a complaint or go to court. Unlawful dismissals are primarily based on discrimination grounds and notice periods.

Meaning of Life Essay

We ask ourselves everyday if our life has meaning. We view our lives and others’ lives in different ways. I agree with life being viewed as a game, and life as learning is adding meaning to our life. I disagree with life having no meaning at all. Every human being views life differently and believes your life is influenced by different ideas and lessons. Life as a game creates a theory that we can’t just take our lives too seriously or else we won’t be happy and feel as if we have fulfilled our lives and/or our purpose on earth. In our textbook it says if you believe your life is a game, you must pick the type of game you wish to play in your life. You can play games that are purely for fun, for superiority, social, hurting your opponents, or to help others. If you pick to have your game of life to be played just for fun then this could possibly be the happiest way to play your game of life. When being able to play a game for fun it excludes the worry of being judged and having to conquer other opponents to become the â€Å"winner† in your game of life. Your opponents could be your friends, family, co-workers, peers, mentors throughout your life and this could make you a miserable person if they turn their backs on you, or fight against your game of life. If we pick to play our life in a game to hurt our opponents then do we decide who our opponent is? Our opponents could be people in our lives who we do not like. They could become our friends and family and if we disagree, then do they become an opponent to us because we don’t see eye to eye? There are so many different ways you could pick to play your game of life. And only you can pick your game, but others around us do influence our choice of what we choose for a game. We don’t want to pick a game to which we are setting ourselves up to become targeted as a â€Å"loser†. We all want to be the â€Å"winner†. I believe in our game of life we should be able to choose if we are going to be the â€Å"winner† in our game of life and who the â€Å"losers† will be. Or should everyone be a winner? Some games in particular could cause chaos in our lives. If we choose to play our life as a competitive game then this could end up giving us enemies, and then what is life really about when you have people against you. In a competitive game it is hard to see the ending outcome of the game, so it is always a gamble to what your life or even the next day might bring. When you don’t know what the next day will bring, does the rules in your game of life change? It is possible when playing a game, the rules will change and new ones can be created and taken away. As little kids playing games, when they don’t like a rule, or merely forget a rule, this changes the game. And these changes affect the outcome of your ending result. Unfortunately I think the rules of your game can change because you learn new things and new technology comes out every day. Life as learning is something we all are introduced to throughout our lives. But do we pay attention to the things life is trying to teach us? Our textbook refers to having a bad experience and turning it into a situation we can learn from. I think we take all situations we are put into and get some kind of lesson or moral meaning out of it. If you view life in different ways then it could change how you react to your life lessons and the idea you should get out of the story. I believe we should all try everything once if it is presented to us and it is morally right. If you can’t live your life to the fullest, then are you actually learning everything you can from your life? Do we encounter things in our life because we should learn from them? Is life supposed to have flaws so we can become a better person and make ourselves better prepared for the next time the problem arises? We can ask ourselves all theses questions and if we listen to the ending result and want to understand then we will take something out of the issue as a life learning situation. But can we shut the ideas and ending decisions out, and ignore the life lesson? I think that each and every event that happens in our life was presented to us to teach us a new life lesson and prepare us better for the next time if it comes up in our life again. These life lessons can hurt us but if life was perfect all the time, then when faced with a flaw in our life we wouldn’t know how to respond and cope with the problem. Some people in life can’t face their flaws of life and walk away or give up. People might do this because they can’t deal with the pain and suffering they believe they are being faced with. With the two philosophies above I do agree that our life is a game, and life is learning. We pick what we want to believe and understand. And in our life we play a game where we can pick the â€Å"winners† and â€Å"losers†. We believe that we make the ending decision in our life and pick what our life stories and experiences actually mean. When we are surprised with conflict and a sudden problem, we might not be able to control our life until we can understand what is going on. And if we take time to understand, then aren’t we still controlling our life? We could always walk away and ignore the new problem. The idea I disagree with the most is life has no meaning at all. Albert Camus said in his book The Myth of Sisyphus that â€Å"the absurd had become a widespread sensibility in our times. † He also relates life having no meaning at all to atheism. If there is no external meaning, then he believes there is no point in life. If life had no meaning then wouldn’t we careless about our future and live for that moment. If life has no meaning then would we be in school trying to receive a quality education? Albert Camus believes that most humans are frightened by the idea of living on earth with no purpose to life. And this allows humans to create a purpose to live. In our textbook it states a quote from his book, â€Å"The gods had condemned Sisyphus to ceaselessly rolling a rock to the top of a mountain, whence the stone would fall back of it own weight. They had thought with some reason that there is no more dreadful punishment than futile and hopeless labor. † This to me means that when you are asked to conquer something that is impossible for you to accomplish, then it is the worse thing that would happen in your life. This makes you feel like you have failed at what god has asked you to do. I believe we all have a meaningful life. Each and every one of us affects someone in the world, either if it’s a positive way or sometimes in a negative way. We won’t always realize our affect on others unless it is pointed out to us. As we discussed in class, a drug addict might share his story, and affect children and teenagers and show them the life they lived and how they are now. I think as a teacher you add meaning to your life by teaching others about a variety of topics in life and history. The question does life have a meaning is worth answering. Each and every one of us has our own opinion of life and if it has meaning. We truly can’t look up the definition in the dictionary and believe that is what life is. We need to look at our personal situations, as well as experiences to see how it molds our view of what life means. The definition of life from The American College Dictionary states â€Å"a corresponding state, existence, or principle of existence conceived as belonging to the soul. † This to me means that as long as we have a presence on earth they have life on earth. This definition isn’t the only one about life; we create our own meaning which is molded to our life. If life is just about existence, then life may have no meaning. We are here on earth to impact people in same way and form. If we are here just for existence then we aren’t living life. In reality I think life can be looked at in many different ways and there is not just one definition. Is their just one definition and would this change the way we live our lives? Would we be different people than who we are today? Life is a special thing, and we can view our life in different perspectives. As mentioned in my paper we can view life as a game, as learning, and life can have no meaning at all. I don’t agree with all the ways we can view our life, but each and every one of us can pick our own way to view life. For me I agree with the fact that life is a game. We pick if we want to play a game for fun, or to be the king of the world. The way we decide to play our life game determines who we are as a person and it helps affect the mood we are in. I also believe life as learning. In life we are given many different life lessons. And what we take from these life lessons is teaching us life. If we don’t take the time to learn, then our life isn’t complete. Or we at least aren’t living our life to the fullest. I disagree with the fact that our life has no meaning. We make our having meaning, and if we don’t put meaning in our life, then it will be meaningless. You might view your life as meaningless, and to others your life could be filled with meaning. Your view of your life can be different than the way others view your life. Life can have many different meanings and can affect our lives in different ways. In the end we choose what our life will be, and how we will live our life. No one else can choose how you should live your life. In the end it is your choice and your choice alone. We can be influenced by others, but they can’t make the final decisions.

Friday, August 30, 2019

Report on Web Programming

INTRODUCTION TO HTML What is HTML? The explosive growth of the World Wide Web is relatively unprecedented, although it resembles the desktop publishing revolution of the early and mid-1980s. As personal computers became more common in homes and offices, people began to learn to use them for document creation and page layout. Although early word processing programs were not terribly intuitive and often required memorizing bizarre codes, people still picked them up fairly easily and managed to create their own in-house publications.Suddenly, the same kind of growth is being seen as folks rush to create and publish pages of a different sort. To do this, they need to learn to use something called the Hypertext Mark-up Language (HTML). HTML at a Crossroads HTML and the World Wide Web in general are currently in a stage of development similar to that of the desktop publishing revolution. Still working to reach maturity as a standard, HTML is feeling the same growing pains that early word p rocessing programs did-as more users flock to HTML, there is a growing need to standardize it and make it less complex to implement.These days, word processors are much more intuitive than they were 15 years ago. There are fewer codes and special keystrokes required to get something done. The applications have matured to the point where most of the low-level formatting is kept hidden from the user of the application. At the same time, the printed page is now more completely mirrored on the computer screen, with accurately represented fonts, emphasis, line breaks, margins, and paragraph breaks. Although programs are quickly being developed to offer similar features for HTML development, these tend to be less than ideal solutions.Currently then, anyone who decides to learn HTML is going to have to know some codes, memorize some syntax, and develop pages for the World Wide Web without the benefit of seeing all the fonts, emphasis, and paragraph breaks beforehand. But anyone who has had any success with word processing programs of ten or 15 years ago (or desktop publishing programs as recently as five years ago) will have little or no trouble learning HTML. Ultimately, you'll see that HTML's basic structure makes a lot of sense for this emerging medium-the World Wide Web.And, as with most things computer-oriented, you'll find that once you've spent a few moments with it, HTML isn't nearly as difficult as you might have originally imagined. A Short HTML History HTML developed a few years ago as a subset of SGML (Standard Generalized Mark-up Language) which is a higher-level mark-up language that has long been a favorite of the Department of Defense. Like HTML, it describes formatting and hypertext links, and it defines different components of a document.HTML is definitely the simpler of the two, and although they are related, there are few browsers that support both. Because HTML was conceived for transmission over the Internet (in the form of Web pages), it is muc h simpler than SGML, which is more of an application-oriented document format. While it's true that many programs can load, edit, create, and save files in the SGML format (just as many programs can create and save programs in the Microsoft Word format), SGML is not exactly ideal for transmission across the Internet to many different types of computers, users, and browser applications.HTML is more suited to this task. Designed with these considerations in mind, HTML lets you, the designer, create pages that you are reasonably sure can be read by the entire population of the Web. Even users who are unable to view your graphics, for instance, can experience the bulk of what you're communicating if you design your HTML pages properly. At the same time, HTML is a simple enough format (at least currently) that typical computer users can generate HTML documents without the benefit of a special application.Creating a WordPerfect-format document would be rather difficult by hand (including all of the required text size, fonts, page breaks, columns, margins, and other information), even if it weren't a â€Å"proprietary†-that is, nonpublic-document format. HTML is a public standard, and simple enough that you can get through a book like this one and have a very strong ability to create HTML documents from scratch. This simplicity is part of a trade-off, as HTML-format documents don't offer nearly the precision of control or depth of formatting options that a WordPerfect- or Adobe PageMaker-formatted document would. Marking Up TextThe most basic element of any HTML page (and, therefore, any page on the Web) is ASCII text. In fact, although it's slightly bad form, a single paragraph of regular text-generated in a text editor and saved as a text file-can be displayed in a Web browser with no additional codes or markings An example of this might simply be: Remember that HTML-formatted documents aren't that far removed from documents created by a word processing prog ram, which are also basically text. Marking up text, then, simply means you add certain commands, or tags, to your document in order to tell a Web browser how you want the document displayed.One of the most basic uses for HTML tags is to tell a browser that you want certain text to be emphasized on the page. The HTML document standard allows for a couple of different types of emphasis including explicit formatting, where you choose to make something italic as opposed to bold, or implicit formatting, where it's up to the browser to decide how to format the emphasized text. Using part of the example above, then, an HTML tag used for emphasis might look something like this: Welcome to my home on the World Wide Web.In this example, and are HTML tags that tell the Web browser which text (in this example, my home) is to be emphasized when displayed. The browser isn't just displaying regular text; it has also taken into account the way you want the text to be displayed according to the HTM L tags you've added. Tags are a lot like margin notes you might make with a red pen when editing or correcting term papers or corporate reports. After you've entered the basic text in a Web document, you add HTML mark-up elements to tell the browser how you want things organized and displayed on the page.In most word processing documents, the â€Å"mark up† that describes the emphasis and organization of text is hidden from the user. HTML, however, is a little more primitive than that, as it allows you to manually enter your text mark-up tags to determine how the text will appear. You can't do this with an MS Word document, but, then again, MS Word documents aren't the standard for all Web pages and browsers on the Internet! The World Wide Web and Web Servers Probably the most important thing to remember about the World Wide Web and the Internet in general is that they are global in scale and often a very cooperative venture.Information on the Web tends to be distributed arou nd the world, and it's just as easy for you to access a site in New Zealand or Japan as it is to access Web information in your own state. The basic reason for learning HTML is to create pages for the World Wide Web. Before you start, though, you'll want to know a little about how this whole process works. We'll begin by taking a look at Web browsing programs, then we'll talk about how the World Wide Web works, and we'll discuss some of the terms associated with surfing the Web.Finally, we'll round out the discussion by talking about the Internet in general and the different services available on the Internet and how they interact with the Web. What's the World Wide Web? The World Wide Web is an Internet service, based on a common set of protocols, which allows a particularly configured server computer to distribute documents across the Internet in a standard way. This Web standard allows programs on many different computer platforms (such as UNIX, Windows 95, and the Mac OS) to pro perly format and display the information served.These programs are called Web browsers. The Web is fairly unique among Internet services (which include Internet e-mail, Gopher, and FTP) in that its protocols allow for the Web server to send information of many different types (text, sound, graphics), as well as offer access to those other Internet services. Most Web browsers are just as capable of displaying UseNet newsgroup messages and Gopher sites as they are able to display Web pages written in HTML. This flexibility is part of what has fueled the success and popularity of the Web.Not only do the Web protocols allow more interactive, multimedia presentations of information, but the typical Web browser can also offer its user access to other Internet resources, making a Web browser perhaps a user's most valuable Internet application. The World Wide Web is the youngest and most unique of the Internet services. Its protocols allow it to transmit both text and multimedia file format s to users, while also enabling Web browsers to access other Internet services. The Web is based on a concept called hypertext, which means that text within the paragraphs on a Web page is designed to act as links to other Web pages.There is no hierarchy on the Web, which is only loosely organized by this system of links. Other services that can be accessed via the Web include Gopher, WAIS, UseNet, e-mail, and FTP. Each of these older Internet services has its own scheme for formulating addresses. Most of these services require a server computer of some sort to allow Internet applications to access their information. These server computers have specific addresses on the Web which you need to know in order to contact them. The World Wide Web is the youngest and most unique of the Internet services.Its protocols allow it to transmit both text and multimedia file formats to users, while also enabling Web browsers to access other Internet services. The Web is based on a concept called h ypertext, which means that text within the paragraphs on a Web page is designed to act as links to other Web pages. There is no hierarchy on the Web, which is only loosely organized by this system of links. Other services that can be accessed via the Web include Gopher, WAIS, UseNet, e-mail, and FTP. Each of these older Internet services has its own scheme for formulating addresses.Most of these services require a server computer of some sort to allow Internet applications to access their information. These server computers have specific addresses on the Web which you need to know in order to contact them. Creating Basic HTML Documents It is important to realize that an HTML document must be built on a very specific framework. This framework, in its simplest form, consists of three sets of matched container tags. A tag is a simple markup element, and always takes the form . A container is a pair of HTML tags of the form . You can think of the element as turning something on, while t he turns that same thing off.For example, consider this line of HTML: This is in Italics. But this isn't. The first HTML tag, , turns on italics. The second tag, , turns them off. When displayed on-screen, this line of text would look like this: This is in Italics. But this isn't. The tags themselves don't appear on-screen. They just tell the browser program how to display the elements they contain. The simplest possible HTML document is given in Listing 4. 1. The entire document is enclosed in the container tags. The first part of the document is encapsulated in the container, which itself contains a container.Finally, the body of the page is contained in a container. The Simplest HTML Document A Very Basic HTML Document My name is Ogbonnaya Stephen Success. The most fundamental of all the tags used to create an HTML document is, not surprisingly, the tag. This tag should be the first item in your document and the corresponding end tag, , should be the last. Together, these tags in dicate that the material contained between them represents a single HTML document (refer to Listing 4. 1). This is important because an HTML document is a plain text ASCII file.Without these tags, a browser or other program isn't able to identify the document format and interpret it correctly. Brief Introduction to PHP What is PHP? PHP stands for PHP: Hypertext Preprocessor PHP is a server-side scripting language, like ASP PHP scripts are executed on the server PHP supports many databases (MySQL, Informix, Oracle, Sybase, Solid, PostgreSQL, Generic ODBC, etc. ) PHP is an open source software PHP is free to download and use Basic Requirements in Working with PHP Notepad++ Xampp server Web Browser 2. 5. 2 SOFTWARE DEVELOPMENT TOOL NOTEPAD++; Notepad++ is a text editor and source code editor for Windows.Fig 2. 5. 2a Screen shot on Notepad++ XAMPP; is a free and open source cross-platform web server solution stack package, consisting mainly of the Apache HTTP Server, MySQL database, and interpreters for scripts written in the PHP and Perl programming languages. X (meaning cross-platform) Apache HTTP Server MySQL PHP Perl The program acts as a free web server capable of serving dynamic pages. XAMPP is available for Microsoft Windows, Linux, Solaris, and Mac OS X, and is mainly used for web development projects. This software is useful while you are creating dynamic webpages using programming languages like PHP, JSP, Servlets.Uses Officially, XAMPP's designers intended it for use only as a development tool, to allow website designers and programmers to test their work on their own computers without any access to the Internet. To make this as easy as possible, many important security features are disabled by default. In practice, however, XAMPP is sometimes used to actually serve web pages on the World Wide Web. A special tool is provided to password-protect the most important parts of the package. XAMPP also provides support for creating and manipulating databases i n MySQL and SQLite among others.Fig 2. 5. 2b XAMPP control Panel Application 2. 5. 3 Basic PHP Syntax A PHP scripting block always starts with . A PHP scripting block can be placed anywhere in the document. A PHP file normally contains HTML tags, just like an HTML file, and some PHP scripting code. Below, is an example of a simple PHP script which sends the text â€Å"Hello World† to the browser: Fig 2. 5. 2 A simple program in PHP using notepad++ The output of this will be gotten by making sure that my xampp server is running and putting in the right address in my web browser. Fig 2. 5. b showing webpage output displaying â€Å"Hello World†. Each code line in PHP must end with a semicolon. The semicolon is a separator and is used to distinguish one set of instructions from another. There are two basic statements to output text with PHP: echo and print. In the example above we have used the echo statement to output the text â€Å"Hello World†. 2. 5. 3 Comments i n PHP In PHP, we use // to make a single-line comment or /* and */ to make a large comment block. Below is a simple program showing single comment line and multiple comment line Fig 2. 5. showing comment line Below is a simple PHP code on PHONEBOOK. This program is able to Add and Delete Name and Phone number in a Phonebook. Fig 2. 5. 4 Output for Adding Data in a Phone Book. From the Output above adding contact name and Phone number, saves the data into the Phone book. While deleting contact also deletes Name and Phone Number in the Phone book. Fig 2. 5. 5; Output after adding Contact Name and Phone number in a Phonebook. The code shown below is a Code Behind file for the sample Phone Book Application that was developed using PHP/MYSQL. Code Behind File

Thursday, August 29, 2019

Relationship between Service Quality and Customer Satisfaction Research Paper

Relationship between Service Quality and Customer Satisfaction - Research Paper Example Additionally, offering good quality services leads to word of mouth recommendation resulting in the increased popularity of a business. The quality of services becomes a more important factor in the hospitality sector. There are assumptions that customer satisfaction is the most reliable indicator of the quality of services. However, there are disagreements on whether hotels should focus on measuring the service quality or the customer satisfaction when determining the areas to improve on.   Background Literature Related to the Problem There are different perspectives regarding the relationship between quality of services and customer satisfaction. Some people argue that satisfaction is a precursor of the quality of services. Others claim that service quality results in customer satisfaction. Different methods have been used to examine how service quality relates to customer satisfaction. ...The level of satisfaction towards a service or good is determined by the perceptions of the consumers or customers. Moreover, satisfaction is crucial in the hotel business since it determines the capability of a hotel to attract new clients or retain the existing ones. Some hotels such as Taj have created ways of getting feedback from their clients to enable them to measure the customer satisfaction towards certain services. This is crucial since the hotels are able to identify areas that require improvement and work on them. Improved service delivery results in the improvement of the overall image of the hotel. Additionally, the quality of services in a hotel can be measured through determining the perception of the customers towards the tangibles such as food. Most customers will determine the quality of a product by considering the price. This enables them to determine if a product is worth a given price or not. According to Nagadevara (2008), the hospitality industry greatly relies on word of mouth communication in getting new customers as well as retaining the existi ng ones. If a customer’s checks into a hotel and is satisfied by the services offered, they are likely to share the experience with their friends who might visit the hotel to enjoy a similar experience. On the other hand, a non-satisfied customer is also likely to share the experience with friends, which will result in the development of distaste towards the hotel. One factor behind the success of Taj hotels is the customer satisfaction. There are different factors contributing to customer satisfaction. One such factor is the beautiful architecture of the hotels that have made them be considered iconic.

Wednesday, August 28, 2019

Nature vs. Nurture in Intelligence Essay Example | Topics and Well Written Essays - 750 words

Nature vs. Nurture in Intelligence - Essay Example He went on to analyze biographical dictionaries and encyclopedias, and became convinced that talent in science, the professions, and the arts, ran in families. This suggestion became know as eugenics, "the study of the agencies under social control that may improve or repair the racial qualities of future generations, either physically or mentally." Galton wanted to speed up the process of natural selection, stating that: "What Nature does blindly, slowly, and ruthlessly, man may do providently, quickly, and kindly". Galton was convinced that "intelligence must be bred, not trained". Such arguments have had massive social consequences and have been used to support apartheid policies, sterilization programs, and other acts of withholding basic human rights from minority groups. In the heyday of eugenic IQ testing in the 1920s there was no evidence for the heritability of IQ. It was just an assumption of the practitioners. Today that is no longer the case. The heritability of IQ (whatever IQ is!) is now a hypothesis that has been tested - on twins and adoptees. The results really are quite startling. No study of the causes of intelligence has failed to find a certain and often substantial heritability. What varies from study to study is the amount that can be attributed to heritability. Evidence in favour of "nurture" "Give me a dozen healthy infants & my own specific world to bring them up in, & I'll guarantee to take any one at random & train him to become any type of specialist I might select - doctor, lawyer, artist, merchant, chef & yes, even beggar & thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors." - John B. Watson, 1924 This was a famous quote in the heyday of behaviorism, when the child was considered to be a 'tabula rasa' (blank slate) onto which anything could be sculpted through environmental experience. This would be a 100% environmental view, but virtually no psychologists would accept such an extreme position today. So, what can we say about nature vs. nurture as causal determinants of intelligence A conservative, seemly safe position is that: "In the field of intelligence, there are three facts about the transmission of intelligence that virtually everyone seems to accept: 1. Both heredity and environment contribute to intelligence. 2. Heredity and environment interact in various ways. 3. Extremely poor as well as highly enriched environments can interfere with the realization of a person's intelligence, regardless of the person's heredity" (Sternberg & Grigorenko, 1997, p.xi). 4. Although most would accept a causal role of genetics, the exact genetic link and how it operates is very far from being understood - another point that most psychologists would agree on. It is certainly not a single gene, but a complex

Tuesday, August 27, 2019

Selection of Global Leadership Assignment Example | Topics and Well Written Essays - 750 words

Selection of Global Leadership - Assignment Example Nevertheless, experts have reacted by instigating broad appraisal concepts covering the obligation to comprehend what is expected from institutional directors, as well as to analyze the mindset along with individual probabilities critical for constructive administration. Though, only minimal basic analysis has been accomplished in the faculty, while a separate recent evaluation in the field has instead opposes most of the reports that were forwarded for the shortage of systematical multiplicity along with logical elasticity. However, generally the appraisal conception is broad and necessitates a lengthy duration to establish as well as to incorporate in the central proficiencies for constructive international direction alongside how to effectually nurture such qualities. Selection practices Among the most dynamic mechanism accessible for global agencies is recruitment; which in the presence of appropriate approach might be the most decisive in appraising latent executive contenders. Even though, integral diversity of an agency as well as the contender could prove to be permanent obstruct during the cross-examination program. Numerous aspects should be weighed when analyzing the ideal mechanism to utilize during a recruitment course, since edifying diversities presents a vast liability in choosing the most predisposed examination practice an agency might adopt to find the most productive workforce. If the company’s resource agent is incompetent of handling cultural diversities imposed by the contenders then the recruitment might definitely result in unconstructive outcome. In such a situation, the foundation would aspire to acquire personnel’s with critical ability to integrate ethical assortments. The interviewee should also be capable of detecting the clandestine distinctions such as eye contact among other individual characters that would represent dissimilar features in separate societies as reported by Mendenhall (2008). According to Edwards ( 2011), numerous models of expression should notably be comprehended for effectual cross-examination program. If recruiting proves to be unfeasible, ethnic understanding entailing various societal coaching concepts might be incorporated to ensure vibrant hiring. Guaranteeing that a recruiter is expansively informed as well as conscious of the duty prior to an interview course should be basic to outlining dynamic staff. Familiarity with the local language can also prove to be an essential device for ensuring an effective interview course. Since the contenders would presume that the agency has no contemplation for the native culture if the executive has not displayed the basic sensitiveness of the surrounding ethnicity and customs. Common variations in linguistics could also result in reflective implication as well as create language obstacles. Over the recruitment course, it might further be extensively constructive to master facts of the interview sessions as well as to be certain th at the contenders have comprehended the relevant inquiries they are to answer (Edwards, 2011). Verifying the scope of hatred that might be apparent between the agency and the immediate contiguous society would also be a prime aspect in outlining an appropriate hiring model. In case there is considerable scope of hatred, then an appraisal model should be adopted to instigate ideal staff for the firm. Assessment might be applied to verify if an aspirant has the precise

Monday, August 26, 2019

Examine the extent to which children have rights in a particular area Essay

Examine the extent to which children have rights in a particular area of law and provision (Abortion) - Essay Example The UK is a signatory to the United Nations Convention on Children’s rights held in the month of December in the year 1991. The Convention acts as a basis for protection of children’s rights in all member states. (Every Child Matters, 2008) The convention provides that all children have the right to life. This brings up a vital question; can a foetus be considered as a child? The United Kingdom recognises viable foetuses as those ones who have exceeded twenty four weeks. (Royal College of Obstetricians and Gynaecologists, 2004) This is why the Abortion Act of 1967 allows abortions before a pregnancy has reached that stipulated time. In relation to this, the UK only allows abortion in cases where the unborn child will affect his mother’s health both physically and mentally. By providing such a restriction, the unborn child’s right to life is protected because mothers may not terminate their pregnancies for minor reasons. This ensures that unborn children’s rights are protected in the most viable way possible. The Abortion Act of 1967 also provides that abortions should only be carried out after obtaining consent from two medical practitioners. (Abortion right, 2007) The purpose of this stipulation is to further ascertain that abortions are only carried out in extreme conditions and that a child’s best interests are protected even before they are born. However, certain human rights groups like the Society for the protection of the unborn child claims that these laws are not doing enough to protect the unborn child. They argue that all abortions should be made illegal through repealing of the abortion acts relevant to women in the UK today. (Arthur, 2007) Experts agree that the United Kingdom’s abortion laws are quite severe to women but protect unborn children through its restrictions. In comparison to other countries in that area, unborn children take precedence over women. In countries like

Sunday, August 25, 2019

Draper Engineering case study Essay Example | Topics and Well Written Essays - 2500 words

Draper Engineering case study - Essay Example Usually, the conditions in the organizational environment – internal and external – influence the potentials of the organization for growth. At this point, the ability of organizational leaders to introduce strategies that will help the firm to increase its competitiveness is critical. Current paper focuses on the examination of the performance of Draper Engineering, a firm operating in the automotive and transport industry. The SWOT analysis is used as a strategic tool in order to identify the firm’s advantages and weaknesses and to check whether its potentials within the particular industry are significant or not. Moreover, the relationship between the firm and its contractors is reviewed and evaluated; measures are also suggested so that the above relationship to be improved, as possible, taking into consideration the current market conditions and the resources available. It is concluded that, currently, the performance of the organization is characterized by a series of failures; the introduction of certain policies, as suggested below, can help the organizational performance to be improved, even in the long term. 2. Draper Engineering – SWOT analysis – improvement of weaknesses 2.1 SWOT analysis In order to understand the current status of the firm in terms of its performance, it would be necessary to develop a SWOT analysis. The specific technique helps to identify a firm’s strengths, weaknesses, opportunities and threats. The advantage of the specific technique is that its elements are not standardized – only their classification in the four above categories needs to have the particular format (Analoui et al. 2003). Otherwise, a variety of organizational characteristics and elements can be included in the specific analysis – depending on the information provided by the organization and the market conditions, which can lead to different assumptions on a firm’s potentials for growth (Burtonshaw -Gunn 2009). For instance, for a specific organization, outsourcing can be a competitive advantage (when the technology used by the firm’s partner is significant and the increase of the firm’s productivity is important); however, for another firm outsourcing may be a weakness, when the contribution of the contractor in the increase of the firm’s performance is quite low while the costs of outsourcing are high. From this point of view, the SWOT analysis of Draper Engineering will be based on the information available but also on the expected performance of the firm in accordance with the current market performance – in other words, the potentials of a firm of this size within the specific industry would be considered as a standard – minimum – of performance which the firm should reach. If it is proved that such performance is not achieved, then the causes for this outcome will be identified and evaluated. The SWOT analysis of the particular o rganization could be developed as follows: a) Strengths The firm operates in the automotive and transport industry, a sector with many perspectives, if taking into consideration the level of the use of its products in markets worldwide. Moreover, the products of the firm are not quite common in the market; in accordance with the case study the firm focuses on the production of ‘drive shafts and track rods’ (case study, p.1) for the particular industry. This means that the firm has two significant advantages: it is part of an industry which has an important presence in the global market and

Saturday, August 24, 2019

Fast Food Centre in Bangalore Research Paper Example | Topics and Well Written Essays - 1500 words

Fast Food Centre in Bangalore - Research Paper Example This is then followed by a conclusion explaining why Wendy's International Inc., one of the largest fast food chains of the world must consider this location. M. G. Road is one of the busiest roads in the city of Bangalore and is lined on one side with retail stores, food outlets and restaurants. It runs from Trinity Circle at one end to Anil Kumble Circle at the other. It has many office buildings, shops and theatres. It is also a home to a large number of buildings and banks. Many Indian cities (including New Delhi and Mumbai) have an M. G. road, and in general there is no linkage between these various roads (except that in many cases, these happen to be the busiest part of the city). India, as the world sees it, is a developing country, showing great progress in its economy. Many MNCs of various industries have turned their attention towards India.The Indian middle class has grown so affluent that they can easily afford to eat out more often compared to a decade ago. In fact, according to a McKinsey report, the Indian food industry grew faster than the information technology industry over the last 10 years. Consumerism is big business in India. There will be 628 million middle-class Indians by 2015. And already, their net income has doubled over the last 10 years. Every multinational company now wants to sell in India. Some companies have failed and others succeeded. The ones that failed did so because they were not sensitive to the cultural factors that affect consumer behaviour in India. One of the key reasons for the increased consumption is the impressive growth of the middle class. At the start of 1999, the size of the middle class was unofficially estimated at 300 million people, larger than the entire population of the United States. And this figure is expected to grow to 445 million by 2006. A detailed survey undertaken by the economic think tank NCAER provides a quick view on how the proportion of the middle segments (UM or upper middle, M or middle and LM or lower middle) has grown over the years since the opening up of the economy. BANGALORE- AN OPPORTUNITY The convergence of professional lifestyles with the demand for fast, tasty food served in a pleasant environment make fast food ventures a leading market area. Bangaloreans are not strangers to the culture of eating out on a regular basis. But such facilities are a definite departure from the traditional fast food outlets. A whole host of trendy, readymade and fast food outlets have mushroomed around Bangalore's new malls and up-market shopping areas catering to time-constrained professionals and the well off middle classes. These new fast food options are burgeoning in Bangalore, because they fit in with changing middle class

Friday, August 23, 2019

Reflection Essay Example | Topics and Well Written Essays - 500 words - 52

Reflection - Essay Example Consequently, the system administration department enhances the prevention of system garbage issues. Garbage (errors) that enter the system will generate garbage outputs. If the wrong math program or number enters the system, the system will produce a wrong math solution or output. Entering the wrong student name in the database will generate avoidable erroneous student –related outputs (Burgess 690). Further, there is a major relation between the human rights class subject and system administration. The system administration personnel interact and communicate with different individuals within and outside the system administration arena. The subject will teach the affected personnel to respect the human rights of the other employees. The subject warns the system administrator and his staff of employees’ gender, age, and other discrimination lawsuits (Gross13). Furthermore, there is an important relation between the environment class subject and system administration. The system administration employees learn to implement the anti-pollution laws. The system administrator must not throw his department’s waste papers into the nearby crystal clear lake, polluting the lake. Similarly, the system administrator should never burn waste paper, polluting the vicinity’s air (Friis 258). There is a noteworthy relation between the globalization class subject and system administration. The class will equip the system administrator and other subordinates with globally-necessary tools. The tools will improve the computer-based systems administrator’s production output. With the incorporation of the latest trends, the administration’s outputs will be at par with other globally recognized system administration departments’ outputs, concerns, goals, tasks, and responsibilities (Bailey 244). There is an influential relation between the self

McDonalds customer service and training model Essay

McDonalds customer service and training model - Essay Example McDonalds have become the byword of fast food industry in the world today. "The company began in 1940 with a restaurant opened by siblings Dick and Mac McDonald, but it was their introduction of the "Speedee Service System" in 1948 that established the principles of the fast-food restaurant." http://en.wikipedia.org/wiki/McDonald%27s_Corporation Unlike usual restaurants, fast food joints have their own pertinent and unbreakable rules. These rules and policies are usually made by the top management and are interpreted and enforced by the Store Manager. Like any other chain businesses, McDonalds too are centrally managed. All the policies and rules are made centrally and the branches and franchises are simply expected to follow them. The least requirement of fast food business is that it has to maintain very high level of service and efficiency throughout to every customer and it should be of unquestionable quality. In addition, cleanliness and safety standards are exceptionally important. Fast food joints manage this through proactive floor control. Rest of all decisions are made by the centre of the organisation, and most of the decisions are foreseen, expected and already clarified. There are a certain differences between the regular res... More stringent and immediate financial control is maintained over the fast foods as money moves fast in these joints owing to brisk business. It is also true that careful and meticulous control at the spot is impossible in places like McDonalds and as such, accounting should be frequent. They cannot afford to wait for the monthly balance sheet. Profit and loss are controlled by accurate inventory aided by the frequent statistical reports and many other systems like ordering of replenishments on time and much in advance, manpower scheduling for the entire month and sticking to it, and urgent building maintenance, maintenance of supporting machinery, including that could be necessary at a later date. The entire concept of fast foods is that of a 'man in a hurry' as they are catering to men in proverbial hurry. So, equal forethought and time slots are allotted to administrative work, documentation, recruitee training, wage reviews, performance reviews and disciplinary actions and awards , pecuniary or otherwise. Efficiency is linked with the increase in the pace of life, according to Ritzer. It is beneficial for consumers and workers both, as more customers get served and profits are increased. "But as is the case with rationalization in general, and each of its dimensions, irrationalities such as surprising inefficiencies and the dehumanisation of workers and customers, emerge from the drive for increased efficiency," (Ritzer, 2000, p.40). According to him, fast food restaurant 'has helped turn efficiency into an increasingly universal reality'. Ritzer argues that because of the fastness of the food, 'the emphasis on quantity tends to affect adversely the quality of both the process and the result'. For customers eating on the run

Thursday, August 22, 2019

The BIMS Management Essay Example for Free

The BIMS Management Essay Team b is providing an overview of the company’s history. Ballard Integrated Managed Services, Inc. (BIMS) is a nationwide company that provides housekeeping and foodservices to not only businesses but also large corporations. BIMS is competitive and the clientele list includes Fortune 100 businesses, numerous midsized firms, many major universities, over a dozen medical centers, and three larger airports. BIMS employs 452 employees, who include full- and part-time workers along with upper management. Even though the annual turnover rate is 55% to 60%, lately the rate has risen over 64% in four months time. Management has not been able to determine the root of the employee discontent, increased sick time, and poor work habits. The lower performance has caused clients to complain. Data Collection Instrument: The data collection tool to let workers express their views about their experiences at BIMS is an employee survey instrument. The survey collects information on attitudes, opinions, and levels of satisfaction from the 449 employees because the upper management is excluded. To figure out the root of the high turnover and the lowered morale, a ten-question survey was conducted. Our consultant firm will just be focusing on for right now on the high turnover. The survey includes questions on demographics that identifies the division the employee is assigned to, how long the employee has been employed, gender, and if the employee is management or not. Some questions include the company’s communications, the quality of training, and the level of compensation. Types of Data Collected The types of data being collected are quantitative only because the data deals with numbers, categories, and the information is measurable. Ballard Integrated Managed Services is surveying all 449 employees to gather information as to why the high turnover has gone too high in such a short period of time in the past four months, we believe that there are several reasoning’s for this turnover but we are going to focus on three out of the many that are there. The three we will focus on will be the quality of training, communication, and level of compensation. Over time, these three reasons could be the cause of the increased turnover and poor performance of  the workers based a few issues we are going to tap into. The questions of communication, communication and the level of compensation are all measurable data based on answers from employees. Level of measurements/ variables Team b is going to identify the level of measurement for each variable that we have chosen including quality of training, level of compensation, and internal company communication. Quality of training includes the four steps of training evaluation: Reaction is how someone feels about training experience Learning is the measurement for increasing knowledge before and after Behavior is the extent of applied learning (implementation) Results the effect of the businesses environment The level of compensation has five step plan that works for employees and employers: Set proper business goals Determine target compensation level Establish a base Add performance incentives Final considerations Internal company communication has an impact on three important areas: Decision making Interdepartmental coordination Team information Data coded BIMS staff used numeric codes to describe the nominal, ordinal, and interval data. The data is prearranged and measured to estimate the processes that were executed. Appendix A describes the routine in which BIMS staff coded the worker survey data numerically. Descriptive statistics were used to current a profile of the data, containing averages, mean, median, and mode, to describe the mid of collection scores or ratings. With the use of ordinal measurements, BIMS staff can use mode, the most mutual value, or median, the middle ranking, to define the central inclination. The study attained within the workers survey used descriptive statistics to expose the results (Lind, Marchal Wathen, 2011). Coding is the process of combining data for  themes, ideas, and categories. It is easier to search and make comparisons. Data Scrub To present the BIMS management with exact outcomes; it is required that a data scrub be achieved to remove of input errors in the sample data. A known error within the data are for those who failed to provide a reply to a survey question—an internal decision was made to enter a zero for any question left blank. There are several of these specific errors present in the sample data—5 zeros are present in the demographic questions and 17 zeros are present question one through 10. Furthermore, there is additional identified error within the data, the result of a keystroke error, which resulted in invalid value of ‘6’ present in inquiries one through 10. The suitable survey answer for inquiries one through 10 should imitate a value of 1,2,3,4,5 with ‘1’ demonstrating ‘Very Negative’ and ‘5’ representing ‘Very Positive’—there are six incidences of this mistake (University of Phoenix, 2011, BIMS, Inc. Part I). Final Analysis The BIMS survey was presented on a voluntary basis to all 449 employees in an effort to capture a consensus of employee perception on work conditions, shifts, training, compensation, fair treatment, company communications, and job security. In addition, there were a small amount of demographics incorporated for filtering. The intention of the survey team was to present their leadership with a reliable statistical analysis that exposes the key components within the raw data that would resolve their concerns over the high turnover. The descriptive and frequency techniques used during the statistical computation will be further manipulated to identify correlation within the data set at a later date. Overall, the survey method was not as effective and yielded below average result with just 78 responses out of the 449 employee population—17.3% overall response rate (University of Phoenix, 2011, BIMS, Inc. Part I). References: Lind, D. A., Marchal, W. G., Wathen, S. A. (2011). Basic statistics for business and economics (7th ed.). New York, NY: McGraw-Hill/Irwin. McClave, J. T., Benson, P. G., Sincich, T. (2011). Statistics for business and economics (11th ed.).Boston, MA: Pearson-Prentice Hall www.onlinestatisticsbook.com www.financialgroup.com

Wednesday, August 21, 2019

Organizational Behavior Leadership Analysis Social Work Essay

Organizational Behavior Leadership Analysis Social Work Essay Academic theories about employee motivation, empowerment and performance are just that theories, they are of little practical use to business leader or their companies, with reference covered to the material cover on the OBL course, and the people management of one Employee of Choice, please evaluate the validity of this statement. Organizational Behavior is the study of behavior of individual, group and people in the organization. It focuses in the relationship between individual and organization in the holistic manner. It focuses on meeting the social objectives, organizational level objectives and individual level objectives. (Leadership and Organizational Behavior, 2010) In managing the organizational behavior with in the organization, there are various managerial theories being proposed by various people to meet the organizational and individual requirement. The role of business leader is to effectively manage the workforce with in the organization to achieve the maximum output from the employees. It is also required from the business leaders to increase the productivity of the organization, to reduce employee turnover, to increase job satisfaction, to reduce absenteeism among the employees, to establish organizational citizenship. The productivity of the employees could be increased by increasing the motivational level of the employees and by imparting training and development programs. An organization is said productive if it converts its inputs into outputs at lowest operating costs. Organizational behavior studies help managers to understand the general behavior of the individuals, but not the exact behavior of the individual. For example Douglas McGregors Theory X and Theory Y give an idea about type of people in the organization. According to Theory X, people would tend to avoid the work and are not responsible, on the other hand according to Theory Y, people are self directed and self motivated. Now this theory does not highlight the exact reasons for being lazy and self-motivated. In this way organizational studies only direct the managers about the general concepts, but could not point the exact behavior of the individual. It is so because the behavior of individual may vary from situation to situation and may also differ from person to person. (Douglas McGregor-Human Relations Contributors, Theory X and Theory Y) The turnover of the employee is another important managerial duty to be considered by leaders. The increase in turnover costs high for the organization by increasing the recruitment, interview, selection and training costs. It is one of the essential parameter to be considered by the managers for increasing the efficiency of the organization. There could be various reasons for increased in turnover. It could be because of work environment, job position mismatch, compensation and rewards, job stress etc. It is required from the leaders to find out the reason for the increase in turnover. As there could be various different reasons for the increase in turnover, the organizational theories could not find the exact reason for the increase in turnover. The method that could be used by manager to find exact reason for the increased turnover could be interviews or survey. With the help of organizational behavior theories leaders could find out the general behavior of the group of employees in the organization, but it is required to carry out individual analysis to find the exact reason for the absenteeism with in the organization. Increasing the Job satisfaction is another important managerial duty. It is essential for leaders to maintain the job satisfaction level of the employees with in the organization. This would not only decrease the turnover of the employees but also generate the healthy environment with in the organization. Organizational Behavior theories help the managers to understand the general behavior of the employee about job satisfaction, but it does not showcase how to increase job satisfaction for a particular employee. According to dispositional theory individual who is happy in his life is happy at his job as well. According to this theory there are the factors affecting job satisfaction i.e. positive and negative affectivity, personality attributes and self evaluation. This theory as well does not find the actual reason specific to a particular individual and hence managers would need to carry out the analysis specific to the individual. Another important function of the business leaders is to reduce absenteeism among the employees. The reduction in absenteeism is directly related to the job dissatisfaction and improper work environment. It is required for the leaders to understand the individual needs and expectations of the individuals from the organization and meet those expectations. It is also observed that unhealthy work environment creates problem for the employee and in turn reduced their efficiency and hence productivity of the organization. Here as well leaders have to sit individually with the employees and seek out the possible hindrances for the employees with respect to work environment. The reasons for the unhealthy work environment could be racial discrimination, manager-subordinates relationship, gender discrimination, work pressures etc. Organization Behavior theories works as the general framework for the leaders but could not act as the specific solution for a particular organizational problem. It require extensive analysis and thorough understanding of the organization and individual behavior to meet the objectives of the organization. Question 2: With reference to Organizational Behavior leadership on gender inequity in organization, and you own work experience if relevant, evaluate the extent to which this issue will require further attention from public and private sector organization in the UAE now and in the future. How can local organization ensure that there is true equity of opportunity for their women Emirati employees and what will be the likely commercial benefits of doing this? Answer: Gender Inequality means differentiation between individuals on the basis of their gender. As per gender inequality the responsibility, human and social possibilities differ from men to that of women. (Long, 2001) It is found that most of the theories showcase the organizational structure as the reason for gender inequality. It is as per organizational structure which causes differences in roles, difference in position, and difference in behaviors between men and women. Materialist theory: As per this theory the connection of men and women with the societys economic structure causes the gender inequality. As per this theory, womens role of mother and wife in the society devalued its right to access high valued resources. Women are less paid as compared to the men in the labor class market. The reason for this is the social responsibility attached to women to take care of family and children. Division between Domestic and Public Work: Their role of mother and wife devalued their role social roles and hence high profile. Women are bound with the domestic responsibilities and hence have to take care of the family and have to invest time there as well. On the other hand men are free from domestic responsibilities and have greater access to high valued resources. It is noticed that there is inequality in pay of men and women, and women are paid less than men. It is also found that two-third of the women works in areas low profile areas like catering, cleaning, clerical jobs, caring jobs. The reason for women being paid less than men is that their job includes discontinuity because of maternity leaves, and to take care of family and children. Moreover still the ratio of highly qualifies women is less than that of men. This gives men an edge to work in high profile jobs and so being paid more than women. Gender Inequality in UAE: The UAE government is trying their best to reduce the gender inequality in UAE. In the year 2008, UAE is participating actively in reducing the gap of gender disparity by organizing various conferences for the same. Dubai School of Government along with Centre of Arab Women for Training and Research and World Bank, organizes a conference to narrow down the gender gap in North Africa and Middle East. The conference named Gender and Economics in MENA: from Theory to Policymaking (ZPRESS, 2008). The main purpose of the conference was to highlight the importance of high education over women. In the conference, Nabeel Al Yousuf, vice chairman of trustee board in Dubai School of Government, focused on gender inequality for the social, national and economic development. Community Development Authority is coordinating with various government and non-government organizations to maintain gender equality. (ZPRESS, 2008) In the recent years UAE has worked well in reducing the gender gap in the emirates. As per a report, UAE has topped in human development chart among gulf countries. Though the ratio of educated women is increasing, but still UAE needs to improve on gender equality. This gender inequality further drags the human development index of the country. The gender equality could be improved with the help of combined effort from public and private companies. Protect Women Rights: It is essential to get women aware of their rights and also make them aware how to fight against the violation of any basic right. This education would help them to fight for their basic rights. It is required for both public and private organizations to coordinate with Convention on the Elimination of All Forms of Discrimination against Women (CEDAW) to protect the rights of women. Women Education: To increase the status of women in the society it is required to further increase the level and quality of education for women. To achieve the same it is required for public and private educational institutions to work together to achieve the common objective. Healthy Work Environment: It is required for the private and public organizations to maintain healthy work environment for the women at workplace. It could be done by providing facilities for women like pick and drop from home, work from home etc. The local organization could ensure the equal opportunity for women by ensuring that jobs are offered as per the qualification and not on the basis of gender. The pay should be equal as per the caliber and qualification of the individual. It is required for the local organization to create equal opportunities for both men and women and should not create any disparity between the two. Gender equality would ensure equal status for the women in the society and would increase their standard of living. It would ensure right investment of the income and less wastage of money. It has been found that women invest 90% of her income on family whereas men only invest 35% of his income on family. This would change political and public welfare policies would increase focus on women as well. Increase in education level of women would reduce the health problems and diseases in the society.

Tuesday, August 20, 2019

Effect of Exchange Rate on Aggregate Demand Shocks

Effect of Exchange Rate on Aggregate Demand Shocks The exchange rate helps insulate the economy from aggregate demand shocks but it may need unsettlingly large changes to do so. This paper will examine the extent to which the exchange rate of a currency can be used to insulate an economy from aggregate demand shocks. First, it will define aggregate demand. Second, it will look at the monetary implications of the aggregate demand curve. Thirdly it will look define aggregate demand shocks and their effect on the aggregate demand curve. Fourthly, it will examine the ways in which the exchange rate can be used to reduce the impact of an aggregate demand shock. Finally, the question of whether using the exchange rate as a means of reducing the impact of an aggregate demand shock will be examined to determine whether it is a feasible strategy and whether the amounts required would be unsettling or not. Aggregate Demand (AD) refers to the total demand (d) in the economy (Y) for goods and services at a certain price level and at a certain time. AD in an economy is the sum of all consumption (C), investment (I), government spending (G) and net exports (NX), where NX is equal to total exports (X) minus total imports (M). This can be represented mathematically as: [1] Aggregate demand is represented by the AD curve, which will show the relationship between price levels and the quantity that producers are willing to provide at that price. The relationship between AD and price is normally negative, showing that the less people are willing to pay, the less firms will produce or, from the other point of view, the less firms charge, the more people will buy. Below is a simple AD ‘curve’: In the chart above, the AD ‘curve’ is represented by a negatively sloped line. If prices (P) are lower, demand (Y) is greater. This negative relationship between price and demand has a number of important monetary consequences. It is necessary to briefly examine these prior to examining the relationship between exchange rates and aggregate demand.[2] Firstly, price levels (P) have a direct relationship to the real value of money. This is because as price levels (P) decrease, the purchasing power of consumers increases, meaning that the real value of the money they hold increases. Likewise, if P increases, consumers get less for the same money, or the real value of their money has decreased. Therefore, P and the real value of money are inversely related to each other.[3] Secondly, decreases in P cause an increase in the real interest rate. Interest rates, the price a borrower pays to borrow, or the return a lender receives for lending, can be expressed as a nominal or real rate. The nominal rate is the amount that must be paid for borrowing, expressed solely in money terms. The real interest rate is the nominal rate adjusted to take account of inflation (p). Thus real interest rates are expressed by the following formula: Thus, the higher p, the lower the real interest rate. Therefore, any increase in inflation will generally lead to pressure on the nominal interest rate to increase, to offset the deduction that will result from inflation. However, as we have seen above, price level decreases add to the real value of money, this is the same as saying that they decrease inflation. A decrease in inflation will mean that real interest rates are now higher than they were before the decrease in inflation. Therefore, price level decreases raise real interest rates and cause pressure for interest rates to be reduced.[4] Thirdly, lower prices increase the international competitiveness of the economy, and this should be reflected in increased international demand for the economy’s exports, causing a rise in net exports and thus in the aggregate demand. Now we will look at aggregate demand shocks. A demand shock is an event that is sudden and unexpected, and has the effect of measurably affecting the demand for goods and services in the economy, either positively or negatively, for a temporary period of time.[5] That is to say, the event shifts the AD curve, either to the right or to the left. A positive demand shock increases demand and shifts the curve to the right, resulting in higher prices. A negative demand shock decreases demand, shifts the curve to the left, and thus leads to a decrease in prices. Any number of events could constitute a demand shock, from an unexpected tax cut that increases consumer spending, to a dip in consumer confidence that decreases consumer spending. Likewise, an economic boom in for example China could result in higher exports to China, increasing demand. The danger of an aggregate demand shock is that they are a cause of uncertainty in the economy. Uncertainty makes it difficult for firms, government and consumers to budget properly and make the most effective investment and saving decisions. Both positive and negative demand shocks can be harmful, however, negative shocks are generally more feared. A negative demand shock, such as a drop in consumer spending, will lead to price decreases and the 2008 global financial crisis has been traced to such a demand shock in the US, which led to a fall in house prices, causing problems in the US subprime mortgage sector that then extended to the rest of the financial sector and wider economy. However, positive demand shocks, such as China’s increased demand for raw materials to fuel its economic growth have led to price increases in a number of important commodities that have also caused economic difficulties around the globe. Therefore, the consensus is that demand shocks of either ty pe are dangerous and any means of dampening them available to governments are desirable.[6] So could exchange rates be used to dampen a demand shock? A brief look at the relationship between monetary factors and the demand curve will demonstrate that exchange rates can be used to affect the demand curve. Therefore, in a positive demand shock, exchange rates could be used to decrease demand and in a negative demand shock, exchange rates could be used to increase demand. The relationship between two currencies may be nominal (e), or it may be real (RER). The real exchange rate takes into account variances in price levels in the two economies. P represents price in the domestic economy and P* the price in the foreign economy. [7] The exchange rate can be used to increase or decrease the price of goods in the economy relative to other economies. This will in turn impact on the international demand for a country’s products. This will impact on the net export figure (NX). A higher exchange rate will decrease international demand and thus will pressure a demand curve towards the left. This could be used to temper a positive demand shock that had increased demand for goods and pressured the curve towards the right. Likewise, a lower exchange rate will increase international demand, increasing exports and shifting the demand curve to the left. This could be used in the event of a negative demand shock to reduce the impact of the shock.[8] Basically, if any sector of demand changes rapidly, the government can seek to push exports in the opposite direction by making them more or less expensive. It is a simple idea and manipulating exports may be more desirable than manipulating other elements of demand, such as government spending, and may be easier to manipulate than, for example, consumer spending. Finally, the question must be asked, is the approach feasible? A central bank can quite easily impact on exchange rates by trading in its own currency. Buying will increase the exchange rate and selling will decrease the exchange rate. However, in order to move a currency value significantly, a central bank would be required to buy or sell a ‘significant’ amount of a currency. So what constitutes a ‘significant amount’ in the foreign exchange market? The global currency market is the largest and most liquid asset class in the world. The accepted size of this market in 2007 was generally put at about two trillion dollars a day. That would make it ten to fifteen times the size of the bond market and fifty times the size of the equities market. That means on a normal trading day, two trillion dollars passes hands. It would take an enormous amount of selling or buying by a central bank to make a dent in this market. A central bank that stepped in to buy or sell a couple of billion dollars worth of their currency would barely be noticed on the market, especially for the major currencies. And the question arises, how would a government fund such an intervention? It is also estimated that about 85 to 90 percent of the forex market is made up of speculators, meaning that attempts to manipulate exchange rates would be vulnerable to massive speculator bets which would have the power to undo any effect a government had on price movements.[9] Also, given the side effects of exchange rate changes, such as the relationship of the exchange rate to inflation, it is likely that the cost of moving the exchange rate, just to get the indirect benefit of altering net exports, would outweigh the benefit.[10] Therefore, it is concluded here that while exchange rates could be manipulated to insulate the economy from aggregate demand shocks, it amount of intervention required would be too large to justify the measure. Bibliography Dutt Ros, Aggregate demand shocks and economic growth, Struct.C.Ec.Dy 18 (2007) 75-99 Hargreaves-Heap, S.P., 1980. Choosing the wrong natural rate: accelerating inà ¯Ã‚ ¬Ã¢â‚¬Å¡ation or decelerating employment and growth? Economic Journal 90, 239–253 Krugman Obstfeld, (2005) International Economics: Theory and Policy, 6th ed., Pearson: London Krugman, (1987) The narrowing band, the Dutch disease and the competitiveness consequences of Mrs. Thatcher, Notes of Trade in the Presence of Dynamic Scale Economies, Journal of Development Economics (Oct) 1987 p. 321 Krugman, (1998) The Age of Diminishing Expectation, MIT Press: Cambridge MA. Li, X.M., 2000. The Great leap Forward, economic reforms, and the unit root hypothesis: testing for breaking trend functions in China’s GDP data. Journal of Comparative Economics 28 (4), 814–827 Perron, P., 1989. The Great Crash, the Oil Price Shock, and the Unit Root Hypothesis. Econometrica 57, 1361–1401 Romer, D., 1996. Advanced Macroeconomics. McGraw Hill: New York. Romer, D., 2000. Keynesian macroeconomics without the LM curve. Journal of Economic Perspectives 14 (Spring (2)), 149–169 Tobin, (1975) Keynesian Models of Recession and Depression, Am. Ec. Rev. 65, 195-202 Footnotes [1] Krugman Obstfeld, (2005) International Economics: Theory and Policy, 6th ed., Pearson: London [2] Krugman, (1998) The Age of Diminishing Expectation, MIT Press: Cambridge MA. [3] Dutt Ros, Aggregate demand shocks and economic growth, Struct.C.Ec.Dy 18 (2007) 75-99 [4] Krugman, (1987) The narrowing band, the Dutch disease and the competitiveness consequences of Mrs. Thatcher, Notes of Trade in the Presence of Dynamic Scale Economies, Journal of Development Economics (Oct) 1987 p. 321 [5] Tobin, (1975) Keynesian Models of Recession and Depression, Am. Ec. Rev. 65, 195-202 [6] Perron, P., 1989. The Great Crash, the Oil Price Shock, and the Unit Root Hypothesis. Econometrica 57, 1361–1401 [7] Romer, D., 1996. Advanced Macroeconomics. McGraw Hill: New York. [8] Romer, D., 2000. Keynesian macroeconomics without the LM curve. Journal of Economic Perspectives 14 (Spring (2)), 149–169 [9] Li, X.M., 2000. The Great leap Forward, economic reforms, and the unit root hypothesis: testing for breaking trend functions in China’s GDP data. Journal of Comparative Economics 28 (4), 814–827 [10] Hargreaves-Heap, S.P., 1980. Choosing the wrong natural rate: accelerating inà ¯Ã‚ ¬Ã¢â‚¬Å¡ation or decelerating employment and growth? Economic Journal 90, 239–253

Monday, August 19, 2019

Free King Lear Essays: The Element of Disguise :: Essays on King Lear

King Lear - The Element of Disguise The play â€Å"King Lear† is, first of all, a play about kingship. Lear is a trusting king, every inch a king, who in his old age brings destruction to himself, certain persons in his own circle, and to his country. â€Å"King Lear† is a play which tears off the outer coverings of human character. Pious and innocent-seeming people who are villainous, are revealed in their true nature, and the similar is disclosed for what it is, as it works destruction. This is done in a world in which most men are constantly seeking their own advancement, a court where flatterers are always lurking, and in which a king should be constantly wary and careful to follow the advice of such honest men as Kent. Within the first two acts of â€Å"King Lear†, the element of disguise is established. The king's two daughters, Regan and Goneril, use flattery as a disguise. They conceal their true feelings, conspiring to take over the land. Goneril says: Sir, I love you more than word can weild the matter; Dearer then eyesight, space, and liberty; . . . Beyond all manner of so much I love you. (II 56-63) Regan speaks: I am made of the same metal as my sister, And prize me at her worth. In my true heart I find she names my very deed of love, Only she comes too short, that I profess Myself and enemy to all other joys Which the most precious square of sense possesses, And find I am alone felicitate In your dear Highness' love. (II72-80) Clearly, the daughters’ words are loaded with flattery. The third daughter, Cordelia, cannot wear the mask that the other two wear, "I love your Majesty According to my bond, no more nor less." (II 97-98) It is for this reason that Cordeila is banished from the kingdom. An obvious example of disguise is with the Earl of Kent, as he enters the play as Tom of Bedlam. Even though he was exiled from the kingdom, he has returned to protect Lear. His great loyalty to the king, forces Kent to risk his life in order to deceive Lear. Lear : What art thou? Kent : A very honest-hearted fellow, and as poor as the king. (I, IV, 18-20)

Sunday, August 18, 2019

Jane Austen :: essays research papers

She puts to rest her pots and pans and takes a new stand. She is conniving and explicit in her manipulative ways. She cares deeply for her beloved children. She fears not being headstrong and liberal-minded, and she truly believes that her epiphanies are gospel truth to her own life. Most important of all, she takes action, is heroic in her boldness to fix the wrong, and does not hesitate to look back on what she leaves behind. In his nineteenth century plays, Henrik Ibsen portrays Norwegian women sharing and contrasting many, and more, of these strong qualities. Like a vigorous and professional artist, Ibsen paints vivid female characters in his skillfully tragic plays, creating diversity among them. In three of his plays alone, A Doll’s House, An Enemy of the People, and Hedda Gabler, women are shown to play various roles under different circumstances in nineteenth century Norway. In these plays, the women’s characteristics range from being maternal and conservative, to being radically liberal and nonconforming.   Ã‚  Ã‚  Ã‚  Ã‚  In Ibsen’s play, A Doll’s House, the protagonist is in fact, a woman, named Nora. At the onset of the play, Nora is shown to be like the traditional mother, simply making preparations for Christmas events. She is portrayed as a strikingly beautiful and almost perfect wife who is affectionate, kind, and always obedient to her husband saying things such as, â€Å"I should not think of going against your wishes.† However, this surface is only a mere cover to what really lies in the heart of Nora. It becomes evident that Nora is not completely complacent with her life. Gradually it becomes evident that she takes pleasures in other things that she does not have. For example, she longs for an affluent lifestyle and indulges in material things because she is more youthfully extravagant than she is maternal. In the play, she even admits herself that she desires grand opulence, saying, â€Å"†¦I used to sit here and imagine that a rich old gentle man had fallen in love with me†¦[and] that he died; and that his will contained†¦ ‘The lovely Mrs. Nora Helmer is to have all I possess paid over to her at once in cash.’† To fantasize about such a greedy thing shows that Nora prefers being a single and wealthy woman in society. Not only was Nora hungry for money, but she was hungry for simple respect. In all the years she was married to Helmer, no one ever took Nora seriously or accredited her with anything.

Saturday, August 17, 2019

Legal Aspects †International Business Law

Executive Summary In order to fully understand the dichotomy of this case there must first be an anlysis of the salient points.   This case of international trade law applies to transactions for goods or services that cross national boundries.   Parties stated herein were affected by disputes regarding contractual rights and duties   The case concerns government substantive and procedural law at an international level. Case backround Bob keyes, CEO of Fullerton-based MemoryTech Inc., initiated telephone and email communications with purchasing agents in Vietnam, Turkey, Great Britain and Mexico.   In his multiple conversations, there were no formal contractual negotitations between MemoryTech and purchasing countries, to his own neglect. Substantive and procedural issues Keyes is determined to file suit against Minh and the Government of Vietnam in an American court.   However, his claim of breach of contract is not substantiated in his argument. â€Å"Procedural law prescribes a method of enforcing rights or of obtaining redress for the invasion of rights.†1   There is no mention, in the text, of any wrongdoing from Minh that would result in penalty.   Unless there is other evidentiary material to prove otherwise, there is an absence of information to build a foundation for this claim. Furthermore, the fact that an official written contract was never endorsed leads to a gray area which would be difficult to interpret in court. The case between Gul and Keyes has a more lucid interpretation. The language in Gul’s fax indicated that, â€Å"any disputes arising out of this contract must be resolved by arbitration in Istanbul.†Ã‚   The assumption here is that the fax was intended to be a written contract initiated by Gul and signed by both parties.   However, for a written contract to be legal and binding, it must be signed by both parties. Keyes did not sign and return the document; therefore, the only avenue available to Gul is to choose an alternative resolution. In addition to this case, there is an incident involving Keye’s daughter, Benn, who made an oral commitment and promise to deliver shirt-pocket computers to several of her classmates.   Generally, courts do not regard oral commitments as a legal and binding contract and, in most cases, interpret them as hearsay. Finally, the accident which occurred in a Mexican warehouse causing serious bodily injury and property damage is a case of punitive damages and should be referred to a CISG advisory council. Specific to this case is the fact that an innocent injured party wants to be compensated for the damage caused by the injury.   International courts will have to address this case with more scrutiny. Legal rights and duties of MT and all other relevant parties All four of these issues are civil cases in which the parties have, available to them, procedural and substantive law.   â€Å"The basic function of civil procedural law is to facilitate the movement of a lawsuit through the legal system.†2 This is a safeguard initiated by international law in order to ensure that each party will be afforded fair and impartial treatment. In addition to their right to procedural law, each party has the right to substantive law which basically encompasses the principles of right and wrong as well as the principle that any civil wrongdoing will result in penalty. What should be done? In brief, MT’s board of directors should seek a second opionion from legal counsel because of the confusion in the interpretation of internationl law from both parties. Traditionally, in this country, parties turn to the court system when they cannot come to an amicable solution by themselves.   However, when disputes arise between parties in international business transactions, parties are reluctant to use foreign courts to resolve their disputes.  Sometimes parties entering an international contract will consider alternative methods of resolving disputes without going to court. These methods, known as Alternative Dispute Resolution (ADR), offer a mechanism of neutrality for resolving disputes. To resolve future disputes without resorting to a foreign legal system, parties should plan ahead by including an ADR clause in their contract.   If this clause would have been included in a contract, the issue between Keyes and opposing parties could have been avoided.3 Works Cited: 1.   Delmar Au: Walston-Dunham, ‘Introduction to Law’, pg. 95 2.   IBID 3.   Kathryn H. Nickerson, (2005), ‘Primer on International Alternative Dispute Resolutions’, Office of the Chief Counsel for Int'l Commerce, pp. 1-2   

Electrical Machines and Drives for Electric, Hybrid

INVITED PAPER Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles Induction and switched-reluctance machines can provide the needed characteristics, but permanent magnet brushless machines offer a higher efficiency and torque density. By Z. Q. Zhu, Senior Member IEEE, and David Howe ABSTRACT | This paper reviews the relative merits of induction, switched reluctance, and permanent-magnet (PM) brushless machines and drives for application in electric, hybrid, and fuel cell vehicles, with particular emphasis on PM brushless machines. The basic operational characteristics and design requirements, viz. a high torque/power density, high efficiency over a wide operating range, and a high maximum speed capability, as well as the latest developments, are described. Permanent-magnet brushless dc and ac machines and drives are compared in terms of their constant torque and constant power capabilities, and various PM machine topologies and their performance are reviewed. Finally, methods for enhancing the PM excitation torque and reluctance torque components and, thereby, improving the torque and power capability, are described. KEYWORDS | Brushless drives; electric vehicles; electrical machines; hybrid vehicles; induction machines; permanentmagnet machines; switched reluctance machines I. INTRODUCTION Electrical machines and drives are a key enabling technology for electric, hybrid, and fuel cell vehicles. The basic characteristics which are required of an electrical machine for traction applications include the following [1]–[3]. †¢ High torque density and power density. †¢ High torque for starting, at low speeds and hill climbing, and high power for high-speed cruising. Manuscript received June 10, 2006; revised November 11, 2006. The authors are with the Department of Electronic and Electrical Engineering, University of Sheffield, S1 3JD Sheffield, U. K. (e-mail: Z. Q. [email  protected] ac. uk; D. [email  protected] ac. uk). Digital Object Identifier: 10. 1109/JPROC. 2006. 892482 Wide speed range, with a constant power operating range of around 3–4 times the base speed being a good compromise between the peak torque requirement of the machine and the volt-ampere rating of the inverter. †¢ High efficiency over wide speed and torque ranges, including low torque operation. Intermittent overload capability, typically twice the rated torque for short durations. †¢ High reliability and robustness appropriate to the vehicle environment. †¢ Acceptable cost. In addition, low acoustic noise and low torque ripple are important design considerations. On an urban driving cycle, a traction machine operates most frequently at light load s around the base speed. Therefore, in general, it should be designed to operate at maximum efficiency and minimum acoustic noise in this region. Typical torque/power-speed characteristics required for traction machines are illustrated in Fig. . Induction machines (IM), switched reluctance machines (SRMs), and permanent-magnet (PM) brushless machines (Fig. 2) have all been employed in traction applications, and can be designed to exhibit torque/power-speed characteristics having the form shown in Fig. 3. In the constant torque region I, the maximum torque capability is determined by the current rating of the inverter, while in the constant power region II, flux-weakening or commutation phase advance has to be employed due to the inverter voltage and current limits. In region III, the torque and power reduce due to the increasing influence of the back-electromotive force (back-EMF). However, the power capability and the maximum speed can be enhanced without sacrificing the low-speed torque capability by employing a dc–dc voltage booster [4], a technique which is employed in the Toyota 0018-9219/$25. 00 O 2007 IEEE †¢ 746 Proceedings of the IEEE | Vol. 95, No. 4, April 2007 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles Fig. 3. Idealized torque/power-speed characteristics. Fig. . Torque/power requirements for traction machines. hybrid system, or by employing series/parallel winding connections, i. e. , series connection at low speed and parallel connection at high speed, as demonstrated in [5] and [6]. In general, however, the design considerations and control methods for the three machine technologies are significantly different, as will be discussed in this paper. Electrical machine design cannot be undertaken in isolation, but must account for the control strategy and the application requirements, both static and dynamic. Hence, a system-level design approach is essential. This paper describes the basic operational characteristics and design features associated with the foregoing electrical machine technologies for traction applications, and reports the latest developments, with particular reference to PM brushless machines, for which there are various topologies. tions are highlighted. Optimal flux, maximum efficiency, and low acoustic noise operation are then discussed. A. Basic Characteristics IMs are robust, relatively low cost, and have wellestablished manufacturing techniques. Good dynamic torque control performance can be achieved by either vector control or direct torque control. For conventional IMs, the constant power range typically extends to 2–3 times the base speed. However, for traction machines, this can be extended to 4–5 times the base speed, which is generally desirable [7]. The torque-speed characteristic of an IM is mainly characterized by the starting torque, the pull-out torque and the associated speed, and the maximum speed. The electromagnetic torque is given by mpVs2 0 Rr s II . INDUCTION MACHINES Of the three electrical machine technologies under consideration, induction machines are the most mature. In this section, the basic characteristics of IMs are briefly reviewed and specific design features for traction applica- T? 2fs !  2 R0 2 Rs ? sr ? Xk (1) and the maximum torque, i. e. , pull-out torque, is 2 Vs2 / s fs Xk Lk Tmax / (2) while the starting torque and corresponding phase current are given by 0 mpVs2 Rr A2 2 i 0 Rs ? Rr ? Xk Tst ? 2fs Fig. 2. Main traction machine technologies. (a) IMVinduction machine. (b) SRMVswitched reluctance machine. c) PMMVpermanent-magnet machine. hA (3) (4) Vs Ist ? q A A 2 0 2 Rs ? Rr ? Xk Vol. 95, No. 4, April 2007 | Proceedings of the IEEE 747 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles where Vs and fs are the supply voltage and frequency, s is the stator flux-linkage, m is the number of phases, p is 0 the number of pole-pairs, s is the slip, Rs and Rr are the stator winding resistance a nd effective rotor cage resistance per phase, respectively, Xk ? Xs ? Xr0 ? fs Lk and Lk are the short-circuit reactance and the total stator and effective rotor leakage inductance per phase, respectively. The pull-out torque is independent of the rotor resistance, approximately inversely proportional to the total stator and rotor leakage reactance, proportional to the square of the stator flux (or voltage), and inversely proportional to the square of the supply frequency. The starting torque is proportional to the square of the supply voltage, while the lower the stator and rotor leakage reactance and the lower the supply frequency, the higher will be the starting torque. Fig. 4. IM traction machine [10]. Rating: 120 Nm, 11. 5 kW at maximum speed of 7600 rpm, 26 kW at base-speed of 2020 rpm. B. Design for Traction Applications In addition to the general requirements cited in the introduction for traction machines, essential design parameters for IMs include the number of poles, the number of stator and rotor slots, the shape of the stator and rotor slots, and the winding disposition. The design process usually involves three stages: 1) making appropriate choices for the pole number and stator/rotor slot numbers; 2) dimensioning the machine and designing the stator winding to achieve a specified power at the base-speed within a specified volume envelope; 3) simulating the machine performance over the full operating speed range. With an inverter fed machine, both a high starting torque and a low starting current can be achieved, since the supply voltage and frequency are variable. Thus, compared with machines designed for constant supply frequency operation certain restrictions, such as the need for a specific rotor slot shape to achieve the required starting torque, are removed. By appropriate choice of supply voltage and frequency, the starting torque can be almost as high as the maximum torque, while a high efficiency can be achieved by minimum slip control [8], [9]. The stator slot number and rotor slot number, and their shape and size should be optimized to minimize the total leakage inductance and resistance. Generally, this favors the use of wide and relatively shallow rotor slots and parallel sided teeth, as opposed to deep bars or double cages in conventional IMs. This results in a lower rotor leakage inductance, which, in turn, improves the power factor and increases the peak torque. In addition, the rotor slot area is more effectively utilized. When combined with the reduced rotor resistance, a lower leakage reactance is also beneficial in reducing the slip frequency at rated torque, and the variation of the slip frequency with load. The speed range of an IM is limited by its pull-out torque at high speed. As will be evident from (2), the pull748 out torque is proportional to the square of the flux-linkage and inversely proportional to the stator and rotor leakage inductances. In the flux-weakening region, the flux reduces with increasing frequency, the consequent reduction in the pull-out torque being exacerbated by the fall in the voltage across the magnetizing reactance due to the influence of the leakage reactance. Therefore, to order to obtain a wide speed range, it is again beneficial to minimize the leakage reactance. In [10], for example, this was achieved by: a) b) c) d) e) increasing the width of the stator slot openings to reduce the stator slot leakage flux; increasing the air-gap length to reduce the harmonic leakage flux; employing relatively wide, open rotor slots to reduce the rotor slot leakage flux; not employing skew so as to eliminate skew leakage; employing a copper cage (Fig. 4). A significant improvement in the available torque at maximum speed was then achieved (Fig. 5). Fig. 5. Torque-speed curve of IM for traction drive [10]. Proceedings of the IEEE | Vol. 5, No. 4, April 2007 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles Over the maximum envelope of the torque/powerspeed characteristic, encompassing both constant torque and constant power operating modes, the copper loss only varies slightly with speed. In contrast, initially the iron loss increases with speed and is a maximum at the base speed, after which it gradually reduces as the degree of flux-weakening is increased. It is well known that when the iron loss and copper loss are similar the efficiency will be maximized. Therefore, an IM for traction applications should be designed such that the iron loss is higher than the copper loss at around the base speed, and vice versa at low and high speeds [9]. In this way, a high efficiency can be maintained over the entire operating speed range by incorporating optimal flux control, i. e. , by reducing the flux level at low torque, as will be discussed later, since the most frequent operating condition generally demands low torque around base speed. Fig. 6. Variation of sound pressure level with flux and load [14]. C. Optimal Flux, Maximum Efficiency, and Minimum Acoustic Noise High-efficiency operation is a very important issue for traction drives. The optimal flux level for maximum efficiency varies directly with the torque and inversely with the speed [11]. Thus, at low torque it is advantageous to reduce the flux in an optimal manner in order to reduce the iron loss and maximize the efficiency. However, as the torque level is increased the flux must be simultaneously increased until the rated flux level is attained; otherwise, the copper loss will increase excessively due to the low torque per ampere. If optimal flux control is employed, a significant efficiency improvement is achieved at all loads in both constant torque and constant power modes [11]–[13]. Above base speed, in the constant power mode, the flux naturally reduces since it is inversely proportional to the speed due to the limited inverter voltage. Optimal flux control for maximum efficiency also results in lower acoustic noise [14], which, in general, increases with both the load and the flux. By way of example, Fig. 6 shows the variation of the sound pressure level with flux and load, for a constant stator fundamental frequency. It will be observed that: 1) 2) under the same flux level, the sound pressure level increases with load; at light loads, a reduction in the flux can significantly reduce the acoustic noise; however, as the load is increased the noise can increase as the flux is reduced; the optimal flux level for the lowest noise emissions increases with the load. usually has to be determined experimentally, since no general and simple analytical method is available [11]. III . SWITCHED RELUCTANCE MACHINES (SRMs) A. Features of SRMs The design and operational features of SRMs are well-documented [15], [16], and may be summarized as follows. †¢ Simple, robust rotor structure, without magnets or windings, which is desirable for high-temperature environment and high-speed operation. However, it can have a significant rotor iron loss. †¢ Potentially low cost, although relatively high manufacturing tolerances are required due to the need for a small air gap. †¢ Modest short-duration, peak torque capability as the magnetic circuit tends to be relatively highly saturated. Smooth operation at low rotational speeds requires relatively complex profiling of phase current waveforms and accurate measurement of rotor position. †¢ Unipolar operation requires nonstandard power electronic modules, but SR drives have an inherent degree of fault tolerance. †¢ Since their operating is based on the sequential excitation of diametrically opposite stator coils in machines having the basic 6/4 and 8/4 stator/ rotor pole number combinations, the acoustic noise, vibration, and torque ripple tend to be relatively high. The high-speed operating capability of SRMs, their relatively wide constant power capability, and the minimal effects of temperature variations offset, to some degree, Vol. 95, No. 4, April 2007 | Proceedings of the IEEE 749 3) Since both vector control and direct torque control, either indirectly or directly, control the flux and torque, optimal flux control can be readily exercised. However, the optimal flux level for each specific torque and speed Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles their relatively lower power factor. Thus, SRMs have significant potential for use in vehicle propulsion systems [7], [17]–[19]. Typical SRMs are shown in Fig. 7, together with one phase leg of the inverter. When a stator pole is aligned with a rotor pole, the phase inductance is a maximum, while in the unaligned position the inductance is a minimum. When operated as a motor, the phase windings are excited during the period when the inductance is increasing as the rotor rotates. When operated as a generator, the phases are commutated on and off during the period when the inductance is reduced as the rotor rotates. The higher the ratio of the aligned inductance to the unaligned inductance, the higher the torque/power capability. In general, it requires the rotor pole arc to be slightly wider than that of the stator poles. Comparatively, SRMs have relatively few feasible stator/rotor pole number combinations (6/4, 8/6, and integer multiples thereof being the most common). Further, the stator poles are generally parallel-sided and carry a concentrated coil, as illustrated in Fig. . However, several alternative SRM topologies have been proposed, of which the longpitched winding SRM [20] which utilizes the variation of the winding mutual inductances, rather than the variation of the phase self-inductances, to produce torque, and the segmented rotor SRM [21] are arguably the most notable, since they may produce a similar torque density to that of conventional SRMs . 3) the degree of saturation in the magnetic circuit; 4) the allowable temperature rise. Thus, a high overload capability requires thicker stator and rotor back-iron and appropriate thermal management. Above base speed in the constant power region, when the inverter supply voltage is limited, commutation advance is required. Thus, both the turn-on and turn-off angles are gradually advanced as the speed is increased, and the machine eventually enters the single pulse mode of operation. When the machine is motoring, the peak current is determined solely by the turn-on angle, while when generating, both the turn-on and turn-off angles influence the peak current [22]. At very high rotational speeds, i. e. , region III of Fig. , further commutation advance is limited due to the influence of the back-EMF and the winding inductance, since the phase current waveforms become continuous. However, as will be described later, by employing two-phase overlapping excitation and continuous conduction the power capability at high rotational speeds can be enhanced. Clearly, the foregoing operational characteristics of an SRM are appropriate for traction applications. B. Operational Characteristics S RMs are usually operated in the discontinuous current mode, although continuous current operation may be advantageous under certain operating conditions. As was shown in Fig. 3, three operational modes generally exist for traction drives. Thus, in the constant torque region I, the phase currents are controlled by PWM to produce the desired output torque, the peak torque capability depending on: 1) the allowable maximum current from the inverter; 2) the rate of rise of the current after a phase winding has been commutated on; Fig. 7. Typical SRMs and one phase leg. (a) Three-phase, 6/4 SRM. (b) Four-phase, 8/6 SRM. (c) One-phase leg of inverter. C. Constant Power Operation An SRM is capable of extended constant power operation, typically up to 3–7 times the base speed [23]. This is usually achieved by phase advancing the excitation until overlap between successive phase currents occurs. The high-speed performance of an SRM depends heavily on the rotor pole design, and in general, requires a compromise between the constant torque and constant power capabilities. For example, in [23] it was shown that when the leading dimensions of 6/4 and 8/6 SRMs were fixed, and the rotor pole arc was varied, the constant power range was extended to 9 6 times base speed when the rotor pole arc was narrower than the stator pole arc and the depth of the rotor pole was relatively large. However, the machines under consideration had relatively low torque densities. The constant power capability also depends on the number of stator and rotor poles. When the number is increased the constant power capability and the overload capability are reduced, albeit the higher the torque/power density and the higher the power factor and efficiency. By way of example, [23] shows that a 6/4 machine exhibits a much wider constant power range (viz. up to $7 times base speed) than an 8/6 machine (viz. up to $4 times base speed), which compares to a constant power operating speed range of $2 times ase speed for a 24/16 SRM [18]. Often, however, the number of stator and rotor poles is dictated by the space envelope constraints. In summary, not only is the ratio of the aligned to unaligned inductance reduced as the number of stator and rotor poles is increased, but the constant power operating speed range is compromised due to the limited scope for phase advancing, and although the consta nt power performance could be enhanced by reducing the number of turns per phase, 750 Proceedings of the IEEE | Vol. 95, No. 4, April 2007 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles Fig. 9. Overlap excitation techniques for extending constant power operating range. (a) Conventional excitation at high speed with phase advance. (b) Overlapping excitation with commutation advanced. (c) Overlapping excitation with commutation retarded. Fig. 8. SRM with integrated flywheel and clutch for mild-hybrid vehicle [25]. Cranking: 45 Nm (0–300 rpm), continuous motoring: 200 Nm (300–1000 rpm), transient motoring: 20 kW (1000–2500 rpm), continuous generating: 15 kW (600–2500 rpm), transient generating: 25 kW (800–2500 rpm). (a) Schematic. b) Rotor/stator without winding. (c) Assembled unit. this compromises the torque capability for a given inverter voltage-ampere rating. Alternatively, the extended high-speed constant power operation can be improved with continuous phase current excitation, by increasing the number of turns per phase. The torque per ampere capability below base-speed is then not significantly compromised, as has been demonst rated for a 24/16 SRM [24] and an 18/12 SRM [25] (Fig. 8), which shows an SRM which was developed for a mild hybrid vehicle application. The use of conduction overlap between two phases to increase the torque and to reduce torque pulsations is common practice [6]. Fig. 9 illustrates overlapping conduction by advancing [6] or retarding [24] long-dwell commutation [15], both also incorporating phase advance. Bipolar excitation (Fig. 10) [6], [22], [26] can also be employed to improve the torque density and reduce torque pulsations, as well as to increase the efficiency. The long flux paths that are associated with SRMs supplied from conventional unipolar drives then become short flux paths, and the torque and efficiency are significantly nhanced at both low and high speeds. However, the improvement in performance gradually reduces as the excitation current is increased and the magnetic circuit becomes more highly saturated. Finally, a control strategy which employs freewheeling diodes in parallel with the power switching devices in a conventional half-H-bridge inverter together with an appropriate zero-voltage period (F ig. 11) can also be used to boost the power capability when an SRM is operated as a generator [22], [27]. Fig. 10. (a) Conventional excitation. (b) Bipolar overlapping excitation. Vol. 95, No. 4, April 2007 | Proceedings of the IEEE 751 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles Fig. 12. Idealized back-EMF and phase current waveforms from PM brushless machines. (a) BLDC. (b) BLAC. Fig. 11. Freewheel diode configuration and (a) ‘‘? 1’’; (b) ‘‘0’’; and (c) ‘‘A1’’ commutation. D. Acoustic Noise, Torque Ripple, and Their Reduction The acoustic noise which is radiated from an SRM is often cited as a major disadvantage. At low rotational speeds the acoustic noise is due predominantly to resonances that are induced by the torque ripples, and may be reduced by appropriate profiling of the phase current waveform. The key to obtaining the optimal current profile is an effective method for estimating the instantaneous torque. At high rotational speeds the acoustic noise is dominated by radial vibration resonances [28]. The acoustic noise becomes significantly higher at high rotational speeds and loads. However, various techniques have been proposed for reducing the vibration and acoustic noise. The most effective method is to employ a relatively thick stator yoke [29], [30] since this increases the mechanical stiffness and, thereby, reduces the vibrational response. However, the outer diameter is then increased, but this, in general, is advantageous in improving the overload capability since the stator yoke becomes less saturated. Reducing the supply voltage is also usually helpful in reducing the acoustic noise at light load. SRMs also generate significantly lower noise when operated under voltage control rather than current control, due to the fact that random switching of the current controller results in a wide-band harmonic spectra, thereby increasing the likelihood of inducing mechanical resonances [31], [32]. In [33], the relationship between the vibration of the stator and the rate of change of the phase currents at turnoff was highlighted, while a current shaping algorithm to limit the rate of change of current at turn-off and, thereby, achieve a smoother radial force waveform was described in [34] and [35]. However, the method proposed in [36] is arguably the most effective, in that it introduced a zerovoltage loop between two step changes in the applied voltage, such that, together with a knowledge of the stator natural frequencies, anti-phase stator vibrations were induced. However, it has limitations [37], since, while it is 752 very effective when SRMs are operated in both single pulse mode and PWM voltage control, it is much less effective with PWM current control, since this results in a varying PWM switching frequency. A fixed frequency current controller can, however, alleviate the problem. Further, the technique is less appropriate for application to SRMs which exhibit multiple resonances. The vibration and acoustic noise can also be reduced [38] by employing two-phase overlapping excitation, which, as stated earlier, is beneficial for extending the constant power operating range. In general, however, the acoustic noise emissions from SRMs remain a significant issue. I V. PERMANENT- MAGNET BRUSHLESS MACHINES A. Brushless DC and AC Machines and Drives Due to the permanent-magnet excitation, PM brushless machines are inherently efficient [39]–[48]. They are generally classified as being either sinusoidal or trapezoidal back-EMF machines [48] (Fig. 12). The corresponding control strategies are usually classified as being either brushless DC (BLDC), or brushless AC (BLAC). In a BLDC drive, the phase current waveforms are essentially rectangular, while in a BLAC drive the phase current waveforms are essentially sinusoidal. Ideally, in order to maximize the torque density and minimize torque pulsations, it is desirable to operate a machine which has a trapezoidal back-EMF waveform in BLDC mode, and a machine which has a sinusoidal back-EMF waveform in BLAC mode. In practice, however, the back-EMF waveforms may depart significantly from the ideal, and, indeed, irrespective of their back-EMF waveform PM brushless machines may be operated in either BLDC or BLAC mode, although the performance, in terms of efficiency and torque ripple, for example, may be compromised. Similar to induction machine drives, when operating at low torque an optimal flux level exists for minimum iron and copper loss, and hence, maximum efficiency. Fig. 13 shows a schematic of a typical PM brushless drive. In both BLDC and BLAC drives, rotor position information is necessary, although the required position Proceedings of the IEEE | Vol. 95, No. 4, April 2007 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles Fig. 13. Schematic of PM brushless drive. esolution is different. For BLDC drives, in which the phase currents only have to be commutated on and off, low-cost Hall sensors are often employed, while for BLAC drives, in which the phase current waveforms have to be precisely controlled, a relatively high-cost resolver or encoder would be generally used. In addition, however, numerous sensorless techniques have recently been developed or are under development for both BLDC and BLAC drives. Although various rotor topologies and stato r winding dispositions ay be employed, BLDC machines predominantly have surface-mounted magnets on the rotor, and a concentrated nonoverlapping, fractional-slot, stator winding [Fig. 14(a)]. This results in short end-windings and, therefore, a low copper loss, and the potential for a high torque density, while a six-step inverter can be employed with PWM current chopping. Two-phase, 120 elec. conduction is the most common operational mode for a three-phase BLDC machine, while maximum torque per ampere in the constant torque region and extended speed operation can realized by advancing the commutation (Fig. 5). Similar operational characteristics can be obtained in a BLAC drive by controlling the phase currents in such a way that they produce a demagnetizing com- ponent of armature reaction, which reduces the effective back-EMF by flux-weakening. Various design features may be employed to obtain a sinusoidal back-EMF waveform. For example, the stator slots and/or rotor magnets may b e skewed, a distributed stator winding might be employed, or the permanent magnets could be appropriately shaped or magnetized, etc. However, a distributed overlapping winding [Fig. 4(b)], results in longer end-windings, which results in a higher copper loss and a lower torque density, while skewing of either the stator or rotor makes manufacture more complicated. Hence, it is often preferable to either shape the magnets or impart a sinusoidal magnetization distribution [49], which results in an essentially sinusoidal airgap field distribution, which is conducive to a low cogging torque and also a low iron loss. The rotor back-iron in a self-shielding, sinusoidal magnetized PM machine [49] is not essential since negligible flux flows within the inner bore of the magnet. This is, therefore, also conducive to a low rotor inertia, which can be an important consideration. Recently, however, there has been a trend to employ a fractional ratio of slot number to pole number and a concentrated stator winding for BLAC motors so as to achieve a sinusoidal back-EMF waveform and a low cogging torque. However, when the slot number per pole is fractional, the reluctance torque is usually relatively small with a concentrated stator winding. In order to utilize the saliency, an overlapping stator winding is usually required [Fig. 4(b)], as will be discussed in Section IV-D. Dq-axis theory can be used to analyze the electromagnetic performance of a BLAC machine, and the optimal relationship between the d-axis and q-axis currents in vector control and flux-weakening control strategies being determined analytically [50], BLAC motors are relatively Fig. 14. Stator winding dispositions. (a) Nonoverlapping winding. (b) Overlapping winding. Fig. 15. Torque-speed character istics of PM brushless machines. Vol. 95, No. 4, April 2007 | Proceedings of the IEEE 753 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles Fig. 17. Comparison of torque-speed characteristics which result Fig. 16. Comparison of torque-speed characteristics of BLAC and three-phase, 120 elec. BLDC drives. with two-phase, 120 elec. and three-phase, 180 elec. conduction modes of operation. easy to control and exhibit excellent performance, in terms of maximum torque per ampere control and optimal extended speed operation [51]–[53]. In contrast, the control strategy to realize constant power operation for a BLDC drive is generally more complex. As was shown in [54] and [55], above the base-speed the maximum achievable output power and torque when a machine is operated in the BLAC mode are higher than that which can be achieved when the same machine is operated in two-phase, 120 elec. conduction BLDC mode, irrespective of whether it has a trapezoidal or sinusoidal back-EMF waveform (Fig. 16). At high speed, the phase current waveform will approximate to a sinusoid even in a BLDC drive, due to the influence of the winding reactance, while any harmonics in the back-EMF waveform will cause the flux-weakening performance to deteriorate. However, by employing a three-phase, 180 elec. conduction strategy, the high-speed power capability of a BLDC machine can be improved, although below base-speed its torque capability will be reduced [48], [55]–[58], as illustrated in Figs. 17 and 18. relatively small and the stator windings have a low inductance, since the magnet has a relative permeability which approximates to that of air, i. e. , r $ 1, and the effective air gap is the sum of the actual air gap length and the radial thickness of the magnets. However, the magnets are exposed directly to the armature reaction field, and, hence, are susceptible to partial irreversible demagnetization. SPM machines are also generally to have a relatively limited flux-weakening capability. However, the flux-weakening capability, as well as the merits of PM machines having a fractional number of slots per pole and a concentrated stator winding, will be discussed later. Fig. 19(a-2) shows a schematic of a motor in which the magnets are inset into the rotor surface. The magnet polearc is, therefore, less than a full pole-pitch. However, since the q-axis inductance is now greater than the d-axis inductance, a reluctance torque can be developed. b) Interior Permanent-Magnet (IPM) Machines: Fig. 19(b) shows examples of brushless machines in B. Permanent-Magnet Brushless Machine Topologies In this section, the basic topologies of PM brushless machine, classified according to the location of the permanent magnets, are described. 1) Radial-Field MachinesVPermanent Magnets on Rotor: A radial-field PM brushless machine may have either an internal rotor or an external rotor, while the PMs may be located either on the surface or the interior of the rotor. ) Surface-Mounted Permanent-Magnet (SPM) Machines: This is the most widely used topology for PM brushless machines [Fig. 19(a-1)]. However, since the d-axis and q-axis stator winding inductances of such machines are the same, they exhibit zero reluctance torque. Further, in general, the armature reaction field is 754 Fig. 18. Torque-speed characteristics for brushle ss BLAC and three-phase, 180 elec. BLDC operation. Proceedings of the IEEE | Vol. 95, No. 4, April 2007 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles onded ferrite or rare-earth, such a machine can exhibit an extremely wide flux-weakening capability and a high torque density, without the risk of generating an excessive back-EMF should an inverter fault occur at high rotational speeds. However, such a rotor structure is rel atively complex and expensive to manufacture [61], [62]. A virtue of the rotor topology shown in Fig. 19(b-2) is that, when the pole number is relatively high, flux focusing can be exploited and the air-gap flux density can be significantly higher than the magnet remanence. Hence, low-cost, low-energy product magnets, such as sintered ferrite, may be employed. By way of example, Fig. 21 shows a generator, which was developed for an electric vehicle auxiliary power unit [63]. Flux-focusing enables an air-gap flux density of 0. 6 T to be achieved when sintered ferrite magnets, having a remanence of 0. 38 T are employed. Such a machine topology also exhibits a higher d-axis inductance since the armature reaction flux only passes through a single magnet, rather than two magnets as in the other machine topologies, making it very suitable for extended constant power operation. ) Radial-Field MachinesVPermanent Magnets on Stator: When the permanent magnets are located on the stator, the rotor must have a salient pole geometry, similar to that of an SR machine, which is simple and robust, and suitable for high-speed operation. The stator carries a nonoverlapping winding, with each tooth having a concentrated coil. The permanent magnets can be placed on the inne r surface of the stator teeth, sandwiched in the stator teeth, or mounted in the stator back-iron. Irrespective of their location, however, the torque results predominantly from the permanent-magnet excitation torque, i. . , the reluctance torque is negligible, although the torque production mechanism relies on the rotor saliency. Compared with conventional permanent-magnet brushless machine topologies, generally, it is easier to limit the temperature rise of the magnets as heat is dissipated more effectively from the stator. a) Permanent Magnets in Stator Back-IronVDoubly Salient PM Machine: The machine topology which is shown in Fig. 22(a) is referred to as a doubly salient Fig. 19. Alternative radial-field PM machine topologies with magnets on rotor. a) Magnets on rotor surface. (b) Magnets inside the rotor. which the magnets are accommodated within the rotor. In Fig. 19(b-1) the magnets are radially magnetized, while in Fig. 19(b-2) they are circumferentially magnetized. General ly speaking, however, leakage flux from the magnets is significantly greater than that in SPM machines. However, since the magnets are buried inside the rotor iron, the magnets are effectively shielded from the demagnetizing armature reaction field during fluxweakening operation. Further, since the d-axis inductance is smaller than the q-axis inductance, a reluctance torque exists, while the d-axis inductance is high compared with that of an equivalent surface-mounted magnet motor topology. Therefore, generally, such machine topologies are eminently appropriate for extended speed, constant power operation in the flux-weakening mode [48], [51]. Indeed, a variant of the topology illustrated in Fig. 19(b-1) is employed in the Toyota hybrid vehicle [4], Fig. 20. The V-shaped disposition of the permanent magnets serves to increase the air gap flux and the distributed stator winding enables the reluctance torque to be utilized. Multiple layers of magnets may also be employed to further increase the saliency ratio, although, in practice, the number of layers is usually limited to 3. An extreme case, however, is to employ an axially laminated PM rotor in which permanent-magnet sheets are sandwiched between the laminations [60]. In this way, a small volume of permanent-magnet material, which is generally a Fig. 20. Open-circuit field distribution in PM BLAC machine in Toyota hybrid vehicle. Vol. 95, No. 4, April 2007 | Proceedings of the IEEE 755 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles permanent magnets is essentially invariant with the rotor position. Therefore, the cogging torque is not significant. However, a major disadvantage is that, due to the unipolar flux-linkage, the torque density is relatively poor compared to that of other PM brushless machines [65], although, as was reported in [66], it can still be higher than that of an induction machine. ) Permanent Magnets on Surface of Stator TeethVFlux-Reversal Permanent Magnet Machine: This machine topology is also commonly referred to as a flux-reversal PM machine [Fig. 22(a)] [67], [68]. Each stator tooth has a pair of magnets of different polarity mounted at its surface. When a coil is excited, the field under one magnet is reduced while that under the other is increased, and the salient rotor pole rotates towards the stronger magnetic field. The flux-linkage with each coil reverses polarity as the rotor rotates. Thus, the phase flux-linkage variation is Fig. 21. Generator for EV auxiliary power unit [63]. 9 kW at 4200 rpm, sintered ferrite magnets (remanence = 0. 38 T), max. air-gap flux density: 0. 6 T. (a) Stator. (b) Rotor. (c) Flux distribution. permanent-magnet machine. For a three-phase machine a magnet is required in the stator back-iron for every three teeth, while for a four-phase machine a magnet is required for every four teeth. The variation of the fluxlinkage with each coil as the rotor rotates is unipolar, while the back-EMF waveform tends to be trapezoidal [64]. Thus, this topology is more suitable for BLDC operation. However, the rotor may be skewed in order to obtain a more sinusoidal back-EMF waveform to make it more appropriate for BLAC operation. Further, it will be noted that the air-gap reluctance as seen by the 756 Fig. 22. Alternative radial-field PM machine topologies with magnets on stator. (a) Magnets in stator back-ironVdoubly salient PM machine. (b) Magnets on surface of stator teethVflux-reversal PM machine. (c) Magnets in stator teethVflux-switching PM machine. Proceedings of the IEEE | Vol. 95, No. 4, April 2007 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles ipolar, while the phase back-EMF waveform is, again, essentially trapezoidal. Such a machine topology exhibits a low winding inductance, while the magnets are more vulnerable to partial irreversible demagnetization. In addition, significant induced eddy-current loss may be induced in the magnets, which also experience a significant radial magnetic force. Further, since the airgap flux density is limited by the magnet remanence, the torque density may be compromised. c) Permanent Magnets in Stator TeethVFlux-Switching PM Machine: This machine topology is also referred to as a flux-switching permanent-magnet machine [Fig. 2(c)] [69]–[71]. The stator consists of BU[-shaped laminated segments between which circumferentially magnetized permanent magnets are sandwiched, the direction of magnetization being reversed from one magnet to the next. Each stator tooth comprises two adjacent laminated segments and a permanent magnet. Thus, flux-focusing may be readily incorporated, so that low-cost ferrite magnets can be employed [70]. In addition, in contrast to conventional PM brushless machines, the influence of the armature reaction field on the working point of the magnets is minimal. As a consequence, the electric loading of fluxswitching PM machines can be very high. Therefore, since the phase flux-linkage waveform is bipolar, the torque capability is significantly higher than that of a doubly salient PM machine [65]. The back-EMF waveform of fluxswitching PM machines is essentially sinusoidal, which makes them more appropriate for BLAC operation. In addition, since a high per-unit winding inductance can readily be achieved, such machines are eminently suitable for constant power operation over a wide speed range. ) Other PM Brushless Machine Topologies a) Axial-Field Machines: Axial-field PM machines have an axially directed air-gap flux [72], [73] and can comprise a single-sided stator and a single rotor, a double-sided stator and a single rotor, or a single stator and a double-sided rotor. In each case, a large axial force exists between the stator and the rotor. As with conventional radial-field PM brushless machines, the stator can be slotted or slotless, a lthough it is more difficult to manufacture a slotted stator for axial-field machines. Thus, slotless designs are more common. However, hile this eliminates cogging, it exposes the winding air-gap flux. Hence, a multistranded conductor or Litz wire may be required to minimize the eddy-current loss. Further, since the effective air gap is large, the winding inductance is generally relatively small, which may limit the constant power speed range. b) Transverse-Flux Machine: Generally, transverse flux machines have a relatively large number of poles, all of which interact with the total ampere-conductors of each phase. This enables very high electric loadings and, hence, high torque densities to be achieved [74]–[78]. However, they have a significant leakage flux and a relatively high winding inductance, as well as a poor power factor [79], [80]. This impacts significantly on the associated VA rating of the power electronics converter, which has inhibited its application. C. Design and Control Issues for PM Brushless Traction Machines As stated earlier, traction machines are required to have a high torque density, a high overload capability, a wide operating speed range, and a high efficiency, while it is desirable that they have a degree of a high fault tolerance and are low cost. In this section, design considerations related to the above issues are discussed. However, they often contradict each other. For example, reduction of the cross-coupling magnetic saturation may also reduce the saliency ratio and consequently the reluctance torque; the selection of the base-speed is usually a compromise between the constant torque performance at low speed and the constant power performance at high speed. 1) Torque Density and Overload Capability: The general torque equation for a PM brushless machine, which has both excitation torque and reluctance torque components, is given by 3 A T? p 2 A m Iq A ? Lq A Ld ? Id Iq (5) where p is the number of pole-pairs, m is the stator winding flux-linkage due to the permanent magnets, and Ld , Lq and Id , Iq are the d- and q-axis inductances and currents, respectively. In order to maximize the torque density, it is desirable to increase m by reducing the leakage flux. This can be achieved by introducing airspace flux barriers or interpole magnets, as illustrated in Fig. 23. m can also be increased by utilizing flux focusing [4], [63], as illustrated in Fig. 24. The torque density can also be enhanced by increasing the saliency ratio [3], [81], as illustrated in Fig. 25. Further, since the short-duration torque capability is determined primarily by the demagnetization withstand capability of the magnets and the level of magnetic saturation, reducing the d- and q-axis cross-coupling magnetic saturation by incorporating air flux barriers, as illustrated in Fig. 26, can enhance the overload capability. 2) Flux-Weakening Capability: It is well known [62], [82] that the maximum flux-weakening capability, defined as the ratio of the maximum speed to the base-speed, under supply inverter voltage and current limitations, can be achieved when a PM brushless machine is designed to have 1. per-unit d-axis inductance such that Ld Ir m Ld ? m Ir or ?1 (6) 757 Vol. 95, No. 4, April 2007 | Proceedings of the IEEE Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles Fig. 24. Flux focusing by appropriate disposition of magnets. ratio is 1. 0. However, the higher the flux-linkage m to achieve a high low-speed torque capability, the more difficult it is to realize wide-speed operation (Fig. 27) [83]. In [62], it was shown that it was possible to design any PM brushless machine to achieve Binfinite[ flux-weakening capability. Clearly, however, if the rated current is high (e. g. the machine is liquid cooled), it is Fig. 23. Reduction of leakage flux by introducing airspace flux barriers or interpole magnets. where m is the stator flux-linkage due to the magnets, Ld is the d-axis inductance, and Ir is the rated current. Although it is possible to design a PM brushless machine which satisfies the foregoing requirement, generally, for most PM machines Ld Ir = m G 1, since the d-axis inductance is relatively low as a consequence of the recoil permeability of the magnets being approximately equal to 1. 0. Nevertheless, the higher the ratio of Ld Ir = m the higher will be the flux-weakening capability [Fig. 7(a)], which, theoretically, is Binfinite[ when the 758 Fig. 25. Improvement of saliency ratio. (a) Lower reluc tance q-axis armature reaction flux path. (b) Multilayer and (c) Axially laminated. Proceedings of the IEEE | Vol. 95, No. 4, April 2007 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles theless, it has been shown [86] that, by careful design, the magnet working point in an SPM machine can remain reasonably high up the magnet demagnetization characteristic, even when the machine has Binfinite[ flux-weakening capability, due to the fact that 1. perunit d-axis inductance results primarily from stator slot leakage and end leakage fluxes. 4) Rotor Eddy-Current Loss: PM BLAC and BLDC machines are usually considered to have negligible rotor loss. However, the rotor loss may be important in machines equipped with surface-mounted magnets, in terms of the resulting temperature rise. Eddy currents may be induced in the permanent magnets, the rotor back-iron, and any conducting sleeve which may be employed to retain the magnets, by time and space harmoni cs in the airgap field. More specifically, they result from [87]: a) stator slotting; b) stator MMF harmonics which do not rotate in synchronism with the rotor; and c) nonsinusoidal phase Fig. 26. Reduction of d- and q-axis cross-coupling magnetic saturation. (a) SPM. (b) IPM. much easier to satisfy (6), even for surface-mounted magnet machines, which have a high m and a relatively low Ld . For example, in [84] Binfinite[ flux-weakening capability was achieved with an SPM machine equipped with a self-shielding, sinusoidal magnetized rotor having no back-iron, and in [85] with an SPM machine in which only alternate stator teeth carried a coil. However, in general, it is much easier to achieve a wide operating speed range with machines equipped with an interior permanent magnet rotor, since generally m is lower, while Ld is higher. 3) Demagnetization Withstand Capability: Operation in the flux-weakening mode is a necessary requirement for traction applications, while NdFeB is the most commonly employed permanent-magnet material for PM brushless machines. However, the magnets are required to have an adequate demagnetization withstand capability at the maximum operating temperature, when they are most vulnerable to partial irreversible demagnetization. In addition to effective thermal management, one means of enhancing the demagnetization withstand capability is to provide a low reluctance path for the demagnetizing d-axis armature reaction flux such that it does not pass through the magnets. One example of achieving this is to employ narrower stator slot openings and thick tooth-tips, as illustrated in Fig. 28(a), or thick rotor slot bridges in an IPM machine, as illustrated in Fig. 28(b). However, such features will also have an influence on m and Ld . In general, however, it is easier to realize a high demagnetization withstand capability for IPM machines. Never- Fig. 27. Variation of torque and power capability with machine design parameters, when Ld Ir G m . (a) Variation with Ld Ir = when m and Lq =Ld are constant. m, Vol. 95, No. 4, April 2007 | Proceedings of the IEEE 759 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles Fig. 28. Improvement of demagnetization withstand capability by introducing d-axis armature reaction demagnetization flux path. (a) SPM stator design. (b) IPM rotor design. Fig. 27. (Continued) Variation of torque and power capability with machine design parameters, when Ld Ir G when Lq and Ld are constant. . (b) Variation with m, current waveforms, which result from six-step commutation and PWM. In general, however, the rotor eddy-current loss is relatively small compared with the stator copper and iron losses. Nevertheless, it may cause significant heating of the magnets, due to the relatively poor heat dissipation from the rotor. In turn, this may result in partial irreve rsible demagnetization, particularly of sintered NdFeB magnets, which have relatively high temperature coefficients of remanence and coercivity and a moderately high electrical conductivity. It is particularly important to consider the rotor eddy-current loss in a) machines with a high fundamental frequency, e. g. high-speed and/or high-pole number; b) machines with large stator slot openings, e. g. , transverse flux machines; c) high power density brushless dc machines, e. g. , force-cooled traction machines with a high electric loading; and d) machines whose windings span a fractional pole-pitch and which have nearly equal pole and slot numbers [88]. If the eddy-current loss is unacceptable, the magnets may be segmented, axially and/ or circumferentially [89]. 60 5) Stator Iron Loss: Due to the fixed PM excitation, the no-load iron loss increases with the rotational speed, while the full-load iron loss in the constant torque operating range is generally around 20%–50% higher. However, the iron loss which results on load in the fluxweakening mode depends on the machine topology, as illustrated in Fig. 29. In general, SPM machines have the lowest full-load iron lo ss, and despite the increase in fundamental frequency it usually becomes much lower than the no-load iron loss as the degree of flux-weakening Fig. 29. Variation of iron loss in SPM and IPM machines when their open-circuit stator iron loss are designed to be the same. Proceedings of the IEEE | Vol. 95, No. 4, April 2007 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles is increased [90]. IPM machines generally have a significantly higher full-load iron loss, which may be comparable to or higher than the no-load iron loss, since the armature reaction field has a higher harmonic content due to the small effective air gap [90], [91]. However, when the magnets are simply inset into the rotor surface the harmonic content in the armature reaction field increases further, and generally results in the highest full-load iron loss [86]. 6) Fault-Tolerance: An important consideration when operating in the extended speed, flux-weakening mode is the consequence of an inverter fault which results in the loss of the demagnetizing armature reaction field and an excessively high back-EMF [92], [93]. In this regard, IPM machines may be advantageous, since, for a given output torque, the PM excitation torque, and, hence, the volume of magnet material and the maximum ack-EMF are lesser. However, the consequences of an inverter fault occurring when a PM brushless machine is operating in the fluxweakening region remains a challenging issue. D. Recent Developments 1) Fractional Slot Machines: SPM brushless machines which have a fractional number of slots per pole and a concentrated winding have been the subject of recent research. T hey have an inherently low cogging torque, short end-windings and, hence, a low copper loss, a high efficiency, and a high power density, as well as excellent flux-weakening performance [85], [94]–[100]. The stator coils may be wound either on all the teeth or only on alternate teeth (Fig. 30) [95], [97]. In the latter case, the phase windings are effectively isolated, both magnetically and physically, and a high per-unit self-inductance can readily be achieved to limit the prospective short-circuit current, by utilizing the relatively high air-gap inductance and the leakage flux at the slot openings. Due to the physical separation of the coils and the negligible mutual inductance between phases, the possibility of a phase-tophase fault is minimized. Therefore, the fault tolerance and flux-weakening capability of such machines can be significantly higher than for more conventional machine designs. Fig. 31 shows a three-phase, 24-slot, 22-pole, PM BLAC machine which was developed for a supercapacitorbased electrical torque boost system for vehicles equipped with down-sized IC engines [99]. However, since the torque is developed by the interaction of a stator spaceharmonic MMF with the permanent magnets, a relatively high rotor eddy-current loss can result from the fundamental and low-order space-harmonic MMFs which rotate relative to the rotor [88], [89]. As stated earlier, however, the magnets can be segmented to reduce the eddy-current loss. A further advantage of such machines is that, due to the fractional number of slots per pole, the cogging torque is very small without employing design features such as Fig. 30. Three-phase, 12-slot, 10-pole, fractional slot PM machines [97]. (a) All teeth wound. (b) Alternate teeth wound. skew. However, the reluctance torque component is negligible even when an IPM rotor is employed. 2) Hybrid PM and Current Excitation: Since the PM xcitation is fixed in a PM brushless machine, the current phase angle has to be progressively advanced as the speed is increased above base-speed so that a demagnetizing d-axis current component is produced which reduces the flux-linkage m with the stator winding. Ultimately, however, this may cause partial irreversible demagnetization of the magnets. At the same time, due to the inverter voltage and current limits, the torque-producing q-axis current component has to be reduced correspondingly. Consequently, the torque and power capability are limited. Thus, a compromise has to be made between the low-speed torque capability and high-speed power capability. Hybrid permanent magnet and field current excitation has been shown to be beneficial in improving the power capability in the extended speed range, enhancing the lowspeed torque capability, and improving the overall operational efficiency. There are several ways of realizing such hybrid excitation. For example, dc winding may be located on the rotor [101] or the stator [102]–[107], which is preferable since it does not require slip-rings. The magnetic circuit associated with the dc excitation may be either in series or in parallel with the magnetic circuit associated with the PM excitation. However, although series excitation is simple it requires a higher excitation Vol. 95, No. 4, April 2007 | Proceedings of the IEEE 761 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles machines equipped with hybrid excitation, based on doubly salient pole [102], consequent-pole [103]–[105], and claw-pole [106], [107] machine topologies. The dc excitation winding enables the air-gap flux, and, hence, the torque capability, to be enhanced at low speed, to be reduced at high speed to facilitate extended speed operation, and to be optimized over the entire speed range to improve the efficiency. It also reduces the likelihood of an excessively high back-EMF being induced at high speed in the event of an inverter fault. Fig. 31. Three-phase, 24-slot, 22-pole, PM BLAC machine with modular stator winding and IPM rotor [99]. Rated output power ? 18. 5 kW, rated speed ? 1700 rpm, rated torque ? 105 Nm. (a) Cross section of three-phase, 24-slot, 22-pole IPM BLAC machine. b) Machine test rig. MMF due to the low recoil permeability of the magnets. On the other hand, parallel excitation is more effective electromagnetically but leads to a more complex machine structure. Fig. 32 shows three examples of PM brushless 762 Fig. 32. Hybrid excited PM machines. (a) Hybrid excitation based on doubly salient pole structure [102]. (b) Hybr id excitation based on consequent pole structure [105]. (c) Hybrid excitation based on claw-pole structure [106]. Proceedings of the IEEE | Vol. 95, No. 4, April 2007 Zhu and Howe: Electrical Machines and Drives for Electric, Hybrid, and Fuel Cell Vehicles V. CONCLUSION The operational characteristics, design features, and control requirements for induction machines, switched reluctance machines, and permanent-magnet brushless machines for vehicle propulsion systems have been reviewed, with emphasis on their low-speed torque and high-speed power capability. Given that they offer a higher efficiency and torque density, particular emphasis has been given to permanent-magnet brushless machines. Various PM brushless machine topologies have been highlighted, and their relative merits have been briefly described. 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