Definition of Reliability in Research

Definition of Reliability in Research Reliability is the degree to which a measurement instrument gives the same results each time that it is used, assuming that the underlying thing being measured does not change. Key Takeaways: Reliability If a measurement instrument provides similar results each time it is used (assuming that whatever is being measured stays the same over time), it is said to have high reliability.Good measurement instruments should have both high reliability and high accuracy.Four methods sociologists can use to assess reliability are the test-retest procedure, the alternate forms procedure, the split-halves procedure, and the internal consistency procedure. An Example Imagine that you’re trying to assess the reliability of a thermometer in your home. If the temperature in a room stays the same, a reliable thermometer will always give the same reading. A thermometer that lacks reliability would change even when the temperature does not. Note, however, that the thermometer does not have to be accurate in order to be reliable. It might always register three degrees too high, for example. Its degree of reliability has to do instead with the predictability of its relationship with whatever is being tested. Methods to Assess Reliability In order to assess reliability, the thing being measured must  be measured more than once. For example, if you wanted to measure the length of a sofa to make sure it would fit through a door, you might measure it twice. If you get an identical measurement twice, you can be confident you measured reliably. There are four procedures for assessing the reliability of a test. (Here, the term test refers to a group of statements on a questionnaire, an observers quantitative or qualitative  evaluation, or a combination of the two.) The Test-Retest Procedure Here, the same test is given two or more times. For example, you might create a questionnaire with a set of ten statements to assess confidence. These ten statements are then given to a subject twice at two different times. If the respondent gives similar answers both times, you can assume the questions assessed the subjects answers reliably. One advantage of this method is that only one test needs to be developed for this procedure. However, there are a few downsides of the test-retest procedure. Events might occur between testing times that affect the respondents answers; answers might change over time simply because people change and grow over time; and the subject might adjust to the test the second time around, think more deeply about the questions, and reevaluate their answers. For instance, in the example above, some respondents might have become more confident between the first and second testing session, which would make it more difficult to interpret the results of the test-retest procedure. The Alternate Forms Procedure In the alternate forms procedure (also called parallel forms reliability), two tests are given. For example, you might create two sets of five statements measuring confidence. Subjects would be asked to take each of the five-statement questionnaires. If the person gives similar answers for both tests, you can assume you measured the concept reliably. One advantage is that cueing will be less of a factor because the two tests are different. However, its important to ensure that both alternate versions of the test are indeed measuring the same thing. The Split-Halves Procedure In this procedure, a single test is given once. A grade is assigned to each half separately and grades are compared from each half. For example, you might have one set of ten statements on a questionnaire to assess confidence. Respondents take the test and the questions are then split into two sub-tests of five items each. If the score on the first half mirrors the score on the second half, you can presume that the test measured the concept reliably. On the plus side, history, maturation, and cueing arent at play. However, scores can vary greatly depending on the way in which the test is divided into halves. The Internal Consistency Procedure Here, the same test is administered once, and the score is based upon average similarity of responses. For example, in a ten-statement questionnaire to measure confidence, each response can be seen as a one-statement sub-test. The similarity in responses to each of the ten statements is used to assess reliability. If the respondent doesnt answer all ten statements in a similar way, then one can assume that the test is not reliable. One way that researchers can assess internal consistency is by using statistical software to calculate Cronbach’s alpha. With the internal consistency procedure, history, maturation, and cueing arent a consideration. However, the number of statements in the test can affect the assessment of reliability when assessing it internally.

Romes Growth- a 2 edged sword essays

Rome's Growth- a 2 edged sword essays Romes Imperial Expansion Was A Two Edged Sword Rome was an extremely resourceful community that, because of their innovative ideas, military leaders and expansion, was eventually turned into an empire. At the same time, it is through these that also turned Rome upside down; there techniques where always the same so it wasnt too difficult for any of their enemies to reverse their own maneuvers on themselves. Over the centuries Rome has become an enormous empire since when it was a small province in Italy, to when it had overtaken Carthage, Germany, Parthians, and majority of the Mediterranean coast. This expansion overseas gave Rome the opportunity to strengthen its empire through war; but, as a drawback the Empire and the republic became unstable and eventually broke down, due to extreme losses during battles against Hannibals army and the Gauls. This expansion overseas made Rome a mighty Empire during the 200s and 100s BC Rome came into conflict first with Carthage, a sea power and trading center on the coast of northern Africa. Although Rome may have been a strong military empire, they still had their weaknesses. Rome had fallen in defeat many times over the centuries, but they just kept getting straight back up and fought again and again. If an army were going to mess with Rome, they would have wanted to be sure that they could defeat them the first time around. Otherwise they would hunt that army down at any extent, to destroy them and make themselves wealthier. The Romans would look to their empire as the instrument that brought law and justice to the rest of the world; in some sense, the relative peace and stability they brought to the world did support this view. They were, however, a military state, and they ruled over this vast region by maintaining a strong military presence in certain countries. The Romans devoted much of their brilliance to ...

Ethical Issues in Profefssional Life (Philsophy course) Essay

Ethical Issues in Profefssional Life (Philsophy course) - Essay Example There are many points in his essay, which are plausible, and worth emulating. However, there are also points, which I do not entirely agree. Therefore, in this essay, I will be discussing the different models upon I agree or disagree with him and the reason why I feel that way. Veach described the engineering model of ethical conduct as straightforward in its presentation of facts to the client and letting the client make an informed decision based on the facts presented. He talks about how this standard could not be applied in the medical profession stating that â€Å"even if the physician logically could eliminate all ethical and the value considerations from his decision making and even if he could in practice conform to the impossible value-free ideal, it would be morally outrageous for him to do so.† On this point, I completely agree with Veach. In the medical profession, we deal with sentient human beings. We do not deal with inanimate objects that do not require any explanations as to how they will be dealt with in furtherance of my profession. My patients are not pipes or drainage systems that I would simply clean, repair and flush when they become clogged with impurities and be done with it. Although medical practice requires precision like any other profession, it is not enough that we discuss statistics and procedures with our patients and expect them to understand the situation. Take the case of a cancer patient for instance. After discussing the advantages and disadvantages of the different types of treatments, it may be morally sound to let the patient choose which form of therapy he/she would prefer. However, in cases where the patient would not choose the most viable option, it would not be ethical on the part of the physician to simply let the patient go on with his/her choice without trying to persuade him/her that such option is not viable. Although I agree with the maxim espoused

Case Study Analysis Essay Example | Topics and Well Written Essays - 1250 words - 3

Case Study Analysis - Essay Example Sam is a self-employed carpenter and has had difficulty securing regular work. Sam is becoming quite annoyed at the situation and has expressed to Myra his disappointment that she has not being able to confront Connor. Myra has been referred by her GP to the local community health center for counselling. You are a social work student on placement at the center. Your supervisor would like you to meet with Myra and identify her needs for counselling. Myra’s case is a case of workplace harassment where an employee infringes on her space as a team member making her life miserable as she serves at the company. Connor a fellow employee who has been sending her suggestive messages may not be aware of the situation she is putting her in considering that we are not told whether Myra has expressed her disappointment with his behavior. This is a form of sexual harassment which can be classified a gender based harassment. Unwelcome conduct is classified as conduct that makes the recipient uneasy or makes him/her feel offended. Sexual attraction is a normal phenomenon in any workplace but the advances made in respect to that should not infringe on the space and rights of the recipient. This is unlawful. However, one should make the individual who is making the unwarranted advances aware that they are not welcome. Legal measures should be taken if the same continues despite the measures being taken to address the issue. The AASW Code of Ethics is clear on the professional boundaries that should be maintained by the social workers or any employees in a given workplace set up. First, it condemns any engagement in any form of sexualized conduct with a person whom they are directly involved in a professional relationship (p. 22). Second social workers are not supposed to engage in any sexualized conduct with a person with whom they were

Comparison Between Gold Rates and Sensex Essay Example for Free

Comparison Between Gold Rates and Sensex Essay Correlation : Correlation is a statistical technique that can show whether and how strongly pairs of variables are related. Correlation is computed into what is known as the correlation coefficient, which ranges between -1 and +1. Perfect positive correlation (a correlation co-efficient of +1) implies that as one security moves, either up or down, the other security will move in lockstep, in the same direction. Alternatively, perfect negative correlation means that if one security moves in either direction the security that is perfectly negatively correlated will move in the opposite direction. If the correlation is 0, the movements of the securities are said to have no correlation; they are completely random. Regression analysis: It involves identifying the relationship between a dependent variable and one or more independent variables. Case Analysis The initial analysis compares two Asset index prices the SENSEX and the GOLD. The Sensex has the top 30 stocks. The Gold is an important Asset in terms on Investment as it also offers the benefit on diversifying the Portfolio risk. To apply the Correlation and regression concept, we consider an investor who plans to invest in Gold looking at the rise in the gold prices. He is still reluctant if he should choose Gold as an investment option or if he should consider investing in some other investment options based on Sensex. as on 15th September 2012. Hence, he plans to carry out a research on the same, for which he attends a seminar on â€Å"Investment Opportunities†. There was a debate amongst the Financial Analysts â€Å"Does Sensex rates affect Gold prices?† Analyst1 : Gold prices have been on an uptick since 2000, while the stock market declined from 2000 to 2003 and then again in 2008. Hence, Sensex fluctuation does not determine the Gold prices i.e. rise in Sensex might not always lead to rise in gold price. Analyst 2: Through the recovery phase that commenced in 2003, gold prices kept rising. Analyst 1: Gold prices normally appreciates in value. Analyst2: Fluctuations in Gold prices are determined by the fluctuations in Sensex i.e.: Decline In sensex. This created a confusion. Hence, to clarify the confusion he plans to study the price trends of the Gold rates and the Sensex for the dates ranging from June 1st’2012 – August 31st2012. After checking the correlation he found that the correlation between the closing prices on Gold and Sensex was 0.24 which was weak. Thus, he decided that Sensex rates was not the only factor to consider investment in Gold. Otherwise, Gold is a good option for investment as it provides diversification and hedging in investment. Conclusion: Correlation between Gold and Sensex is 0.24 which is positive and weak. Thus, based on this correlation change in Sensex has an effect on Gold rate but it is very small.

The Insanity Defense Essay -- Argumentative Persuasive Essays

The Insanity Defense Former U.S president Ronald Reagan was shot by a man named John Hinckley in the year 1981. The president along with many of his entourage survived the shooting despite the heavy infliction of internal and external injuries. The Hinckley case is a classic example of the 'not guilty by reason of insanity' case (NGRI). The criminal justice system under which all men and women are tried holds a concept called mens rea, a Latin phrase that means "state of mind". According to this concept, Hinckley committed his crime oblivious of the wrongfulness of his action. A mentally challenged person, including one with mental retardation, who cannot distinguish between right and wrong is protected and exempted by the court of law from being unfairly punished for his/her crime. (1) What is "insanity" and why is this subject of much controversy? Although I do not have a clear definition of insanity, most socially recognized authorities such as psychiatrists, medical doctors, and lawyers agree that it is a brain disease. However, in assuming it is a brain disease, should we link insanity with other brain diseases like strokes and Parkinsonism? Unlike the latter two, whose causes can be medically accounted for through a behavioral deficit such as paralysis, and weakness, how can one explain the behavior of crimes done by people like Hinckley? (2) Much of my skepticism over the insanity defense is how this act of crime has been shifted from a medical condition to coming under legal governance. The word "insane" is now a legal term. A nuerological illness described by doctors and psychiatrists to a jury may explain a person's reason and behavior. It however seldom excuses it. The most widely known rule in... ... a reversible state. When the defendant no longer tests positive in legal tests, an insane person miraculously becomes sane. Unfortunately, the same law does not account or recognize the physical, emotional or psychological states that may or may not be reversible. Works Cited: 1)All About the Insanity Defense, Mark Godo http://www.crimelibrary.com/criminal%5Fmind/ 2) Does Insanity "Cause" crime? : Thomas Szasz, M.D., The Myth of Mental Illness (1960) 3)M'Naghten Rule http://www.law.cornell.edu/journals.html 4)The Yates case: Commentary for United Press International; Susan Crump is a former prosecutor for Houston http://www.geocities.com/mental_illness 5) Donald E. Watson, MD taught and did research in nueropsychology, teaches at UC Irvine Medical School. http://www.enformy.com/ 6) Statistics http://www.crimelibrary.com/criminal%5Fmind/ The Insanity Defense Essay -- Argumentative Persuasive Essays The Insanity Defense Former U.S president Ronald Reagan was shot by a man named John Hinckley in the year 1981. The president along with many of his entourage survived the shooting despite the heavy infliction of internal and external injuries. The Hinckley case is a classic example of the 'not guilty by reason of insanity' case (NGRI). The criminal justice system under which all men and women are tried holds a concept called mens rea, a Latin phrase that means "state of mind". According to this concept, Hinckley committed his crime oblivious of the wrongfulness of his action. A mentally challenged person, including one with mental retardation, who cannot distinguish between right and wrong is protected and exempted by the court of law from being unfairly punished for his/her crime. (1) What is "insanity" and why is this subject of much controversy? Although I do not have a clear definition of insanity, most socially recognized authorities such as psychiatrists, medical doctors, and lawyers agree that it is a brain disease. However, in assuming it is a brain disease, should we link insanity with other brain diseases like strokes and Parkinsonism? Unlike the latter two, whose causes can be medically accounted for through a behavioral deficit such as paralysis, and weakness, how can one explain the behavior of crimes done by people like Hinckley? (2) Much of my skepticism over the insanity defense is how this act of crime has been shifted from a medical condition to coming under legal governance. The word "insane" is now a legal term. A nuerological illness described by doctors and psychiatrists to a jury may explain a person's reason and behavior. It however seldom excuses it. The most widely known rule in... ... a reversible state. When the defendant no longer tests positive in legal tests, an insane person miraculously becomes sane. Unfortunately, the same law does not account or recognize the physical, emotional or psychological states that may or may not be reversible. Works Cited: 1)All About the Insanity Defense, Mark Godo http://www.crimelibrary.com/criminal%5Fmind/ 2) Does Insanity "Cause" crime? : Thomas Szasz, M.D., The Myth of Mental Illness (1960) 3)M'Naghten Rule http://www.law.cornell.edu/journals.html 4)The Yates case: Commentary for United Press International; Susan Crump is a former prosecutor for Houston http://www.geocities.com/mental_illness 5) Donald E. Watson, MD taught and did research in nueropsychology, teaches at UC Irvine Medical School. http://www.enformy.com/ 6) Statistics http://www.crimelibrary.com/criminal%5Fmind/

Art of War Summary Essay

Art of War is a famous Chinese military strategy book written by Sun Tzu, an ancient Chinese military general. He was famous during his time and for his work entitled Art of War, which made him known even up to our century. According to Wallace (2010), Sun Tzu is the author of one of the most prominent pieces of literature during the era of the Warring States in which China entered around the first millennium B.C.E. In this work of art Sun Tzu takes a rational approach to the problem of conflict and dissects every aspect of it. Sun Tzu is undeniably an historical figure. The book is all about how to win a war by employing strategies and tactics given the information and ideas that every general must know from laying plans, handling his army, giving commands, positioning, maneuvering and all other important aspects mentioned by Sun Tzu. The book is concentrated on war strategies and tactics but Sun Tzu’s philosophies from the Art of War can be viewed from many perspectives. It can be applied on many circumstances including strategic management, the strategies and tactics that were laid on the book can be applied to many aspects of business management. Sun Tzu’s ideas believed that laying plans is vital before making any move. This idea is the same as careful planning and gathering reliable information before making any decision in strategic management. Assessing one’s environment is helpful in a business perspective, too. Know yourself, know your enemies. Knowledge is as important as guns and bullets in engaging war. Knowing the enemies and your own strengths and weaknesses is similar to SWOT analysis. Economic aspect must be considered in engaging business same as engaging in a war. Time is of essence that’s one thing that is common to war and strategic management. In business, decisions must be made in a timely manner. Be moral and ethical. Sun Tzu included Moral Law as one of the constant factors. In business, customers usually patronize those who are known for their ethical behaviour.   The true leader knows both how to utilize his resources and when to make a decision. He plans by making a combination of direct and indirect tactics. Handling resources and decision making are constant activities both in war and in managing business. Sun Tzu’s classical book was intentionally written for the conduct of war but his ideas and perceptions don’t just fit for war. The book addresses strategy in broad manner making it applicable to strategic management. II. Summary The first chapter of the book concentrates on ideas and information that a general must be aware of. The art of war is governed by five constant factors, all of which need to be taken into account. They are: the Moral Law; Heaven; Earth; the Commander; Method and discipline. These factors should be known to every general because this will serve as guidelines in conduct of a war. Knowledge on one’s environment and assessment of it is important to achieve victory. Sun Tzu believes that deception and intelligence will bring home the bacon. Second chapter’s central idea focused on how to do the battle, the tactics that must be employed when the battle is on and the economic aspect of war. Sun Tzu mentioned in this chapter that when you do battle for a long time it will dull your forces and exhaust your resources. Prolonged warfare only brings poverty to a country. Proper timing on when to attack, valuing every minute during the war, and making victory as the objective of every war will prevent prolonged warfare. Be flexible. Be a clever fighter. These are Sun Tzu’s message in the next two chapters. The fifth chapter tackles force and domination as a tool to build momentum. â€Å"The control of a large force is the same in principle as the control of a few men: it is merely a question of dividing up their numbers. Fighting with a large army under your command is not different from fighting with a small one: it is merely a question of instituting signs and signals.† This just means that a large size of the army doesn’t secure victory, proper handling of men and right commands somehow does. Avoid being deceived and shaped. The army must remain invisible to its enemy and maintain unity. Sun Tzu emphasizes in the sixth chapter that an army must know their own strengths and weaknesses. Then, figure the enemy’s strengths and weaknesses with the help of deception. By this, one can see the opportunities and threats brought by the environment. Maneuvering is the seventh chapter’s focus. Sun Tzu said that tactical maneuvering is difficult. Yes it is. Keeping an advantage is hard to maintain but this is very essential to shield your army from defeat. The next chapters are focused on how to respond on different war situations. Adaptation is elaborated in the eighth chapter of the book. Sun Tzu focuses on the need for flexibility in this chapter. He explains how to successfully respond to shifting circumstances. The succeeding entitled â€Å"The Army on March† describes how the army must move from one place to another, paths that requires expertise before you can go through it and the areas that must be avoided to maintain advantage. Chapter ten looks into the general aspects of resistance and the six kinds of terrains or field positions which each of which offers advantages and disadvantages both in terms of advancing position and defending the army. Sun Tzu said that the art of war recognizes â€Å"Nine situations† and these are elaborated in the eleventh chapter. These are: dispersive ground; facile ground; contentious ground; open ground; ground of intersecting highways; serious ground; difficult ground; hemmed-in ground; desperate ground. Translators say that these nine situations can be generally grouped into early, middle, and late-stage conditions, and they range from scattering to deadly. In each of these situations, there is one and only one appropriate response. As the title says, â€Å"Attacking by fire† this chapter is basically lays down the five different ways to attack the enemy using fire. First, burn the soldiers in their camp. Second, burn their stores. Third, burn their equipment. Fourth, burn their weapons. Lastly, burn their supplies. The ways mentioned have been widely used by many battles. The last chapter focuses on the importance of gathering information from reliable sources and managing them. It specifically discusses the value and methods of developing good information sources. It describes five kinds of spies: local spies, inside spies, reverse spies, dead spies, and living spies. Reliable information can help mold your own strategy and gain competitive advantage.

Reflection on Global Operation Management Essay

Pietra Rivoli who is an associate professor in the Georgetown University, specializes in finance and social issues, and is the author of the book, ‘The Travels of a T-shirt in the Global Economy’. The main reason which instigated Rivoli to write this book, was a speech a student had given at the Georgetown University, the student was severely criticizing globalization, and asking about who made the T-shirts they were wearing. She told some facts about child labor in India and Vietnam, which made everybody, sit up and think, including Rivoli. Rivoli then starts on a journey to find out some interesting facts about the origin of the T-shirt. Her case study starts in Texas at the home of Nelson Reinch, who produces enough cotton for more than 1.3 million T-shirts. Reinch and his colleagues control the whole world market of cotton, through hard work, determination, modern technology and much needed discounts from the government. Reinch was no where in comparison to the poor farmers in India and Africa, who did not have proper funds or government support in marketing their goods. Rivoli’s next stop was China, were she met a young woman Yuang Zhi, who spun the yarn for the fabric and sewed the shirt. This young lady worked for 50 hours a week, and earned nearly $150 per month. This woman’s working conditions were far better than the conditions in which women had to work previously in Manchester and England. This was probably the woman’s first encounter with independence and identity, which came in the form a paycheck, even though it was a small amount.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The most important point which was very surprising was that, throughout the world there must be millions of people who manufacture cotton, but the manufacturers from Texas were totally dominating the cotton industry, because of their shrewd manner by which they manage to avoid competition. These manufacturers manage to control the market by avoiding the labor market, which make the other manufacturers unable to compete with them due to no government and political assistance, lack of proper education and money. People who support globalization vow by the free trade of clothes, as it can be used to the advantage of the poorer countries. Rivoli was surprised to find that how recycled clothes from the USA were a rage in Tanzania. Used clothes from America get imported in huge quantities to Tanzania. Tanzania is a small country which was slowly proceeding towards a more liberal capitalist system from the socialist model. People are able to freely take part in the daily auctions of the clothes at the market place, and merchants are also making a mark for themselves in the cutthroat markets as consumers or retailers. Rivoli feels that free trade should be encouraged without any government or political interference in the markets. According to the author, United States is on the top of the market whereas Africa is at the bottom; she feels that USA will have a better chance to make progress economically if they give a reasonable chance of competition to other poorer countries. Tanzania is a proper example of how a free market should work, and these markets are extremely professional, but do not get acknowledged, because of the low capital raised through such markets, which is not significant. Two of the most important principles which need to be followed are that, government and political interference should not be there in any market. Another point is that the subsidy which US government gives the cotton manufacturers is indirectly harming other poorer countries. Rich people are becoming wealthier and the poor are becoming poorer. If the subsidies are reduced, the price of cotton can be increased, which would be beneficial to other poorer markets. Another important point which is a shock is that the clothes that people donate, are not given away freely to poor people, but are sold to middlemen for huge profits, which later land in the streets of   the Tanzania marketplace. Some of the most important principles which can be followed by other industries also are that free market in any trade should be encouraged, and people should have the power to voice their demands, meaning a free democracy should be prevalent to achieve a fruitful society. Government should support free trade in any industry, and should provide the necessary platform in the form of proper education and capital to help the markets grow. Some of the other reasons for the trouble that African industries are facing are the lack of proper authority, which is due to no proper education, corruption and insecurity. The author Rivoli made a very good job of the book, she was successful in exposing the secrets and complications of the cotton trade globally.   Her views on free trade and liberal democracy are very interesting, and should be followed by the authorities of the poorer countries for a better society. On the whole she succeeded in voicing her thoughts and opinions on the recycle market in Tanzania, and hopefully, their government will provide a strong platform for such global trades. References Kris Hundley, What a T-shirt Teaches Series., St Petersburg Times, 4 October 2007, . Lauren Dorsey, Lauren Barbieri, Zack Thomas, ‘The Travelers of a T-Shirt in the Global Economy, by Pietra Rivoli’, 4 October 2007, .

WEEK 6 DQ 2 Example

WEEK 6 DQ 2 Example WEEK 6 DQ 2 – Article Example Number Financial Controls in an Organization The finance management of an organization is among the most important aspects of the organization. For any business institution to ensure that it keeps a correct and accurate track of their financial assets, it is important to have different financial controls. They are tools used by an organization to track the finances of the organization so as to ensure that there are maximum returns on the investments of the organization (Griffin, 413).Financial statements are among the most important tools that are used by organizations in this endeavor. They are generally important records that may be kept by an organization or any business entity for formality. Studies give numerous reasons as to why this tool is among the most important tools used to check the financial position of an organization (Buffet & Clark, 18).Financial statements are vitally useful in the determination the progress of the business entity. In most cases, financial statement s regarding assets and liabilities are used to evaluate whether a business is making profits or losses. This is very important in the sense that the organization is in a better position to evaluate the strategies that need to be implemented for the success of the organization (Fabozzi & Drake, 1-5).They are also used by the management of the organization in order to plan for the future goals and objectives of the organization. In most cases, the goals of the organization are bound to fade due to time and improvements in technology. In order to ensure that the organization competes well in the market, the goals have to be adjusted order to match those of the current trends in the market (Plunket et al. 497).Plunkett, W. R., Allen, G. S., & Attner, R.F. Management: Meeting and exceeding customer expectations (10th Ed.). Mason, OH: South-Western Cengage Learning Publishers. 2013. PrintGriffin, R. Fundamentals of Management. New York: Cengage Learning Publishers. 2013. PrintBuffet, M & Clark, D. Warren Buffett and the Interpretation of Financial Statements: The Search for the Company with a Durable Competitive Advantage. U.S.A: Simon and Schuster Publishers. 2008. PrintDrake, P.P & Fabozzi, F.J. Analysis of Financial Statements. New York: John Wiley and Son Publishers. 2013. PrintPlunkett et al. Management: Meeting and Exceeding Customer Expectations. New York: Cengage Learning Publishers. 2007. Print

Cylinder Deactivation Variable Engine Displacement

Cylinder Deactivation Variable Engine Displacement What is cylinder deactivation? It is a method used to create a variable displacement engine that is able to supply the full power of a large engine under high load conditions as well as the fuel economy of a small engine for cruising. The Case for Cylinder Deactivation In typical light load driving with large displacement engines (e.g. highway cruising), only about 30 percent of an engine’s potential power is utilized. Under these circumstances, the throttle valve is only slightly open and the engine has to work hard to draw air through it. The result is an inefficient condition known as pumping loss. In this situation, a partial vacuum occurs between the throttle valve and the combustion chamber- and some of the power that the engine makes is used not to propel the vehicle forward, but to overcome the drag on the pistons and crank from fighting to draw air through the small opening and the accompanying vacuum resistance at the throttle valve. By the time one piston cycle is complete, up to half of the potential volume of the cylinder has not received a full charge of air. Cylinder Deactivation to the Rescue Deactivating cylinders at light load forces the throttle valve be opened more fully to create constant power, and allows the engine to breathe easier. Better airflow reduces drag on the pistons and the associated pumping losses. The result is improved combustion chamber pressure as the piston approaches top dead center (TDC) and the spark plug is about to fire. Better combustion chamber pressure means a more potent and efficient charge of power is unleashed on the pistons as they thrust downward and rotate the crankshaft. The net result? Improved highway and cruising fuel mileage. How Does it All Work? In a nutshell, cylinder deactivation is simply keeping the intake and exhaust valves closed through all cycles for a particular set of cylinders in the engine. Depending on the design of the engine, valve actuation is controlled by one of two common methods: For pushrod designs- when cylinder deactivation is called for- the hydraulic valve lifters are collapsed by using solenoids to alter the oil pressure delivered to the lifters. In their collapsed state, the lifters are unable to elevate their companion pushrods under the valve rocker arms, resulting in valves that cannot be actuated and remain closed.For overhead cam designs, generally a pair of locked-together rocker arms is employed for each valve. One rocker follows the cam profile while the other actuates the valve. When a cylinder is deactivated, solenoid controlled oil pressure releases a locking pin between the two rocker arms. While one arm still follows the camshaft, the unlocked arm remains motionless and unable to activate the valve. By forcing the engine valves to remain closed, an effective â€Å"spring† of air is created inside the deactivated cylinders. Trapped exhaust gasses (from previous cycles before the cylinders were deactivated) are compressed as the pistons travel on their upstroke and then decompressed and push back on the pistons as they return on their down stroke. Because the deactivated cylinders are out of phase, (some pistons traveling up while others are traveling down), the overall effect is equalized. The pistons are actually just going along for the ride. To complete the process, fuel delivery for each deactivated cylinder is cut-off by electronically disabling the appropriate fuel injection nozzles. The transition between normal operation and deactivation is smoothed by subtle changes in ignition and camshaft timing as well as throttle position all managed by sophisticated electronic control systems. In a well-designed and executed system, the switching back-and-forth between both modes is seamless- you really don’t feel any difference and have to consult the dash gauges to know that its happened. Read more about cylinder deactivation at work in our review of the GMC Sierra SLT flex-fuel, and see the instant fuel economy it generates in the GMC Sierra test drive photo gallery.

Writer's choice Essay Example | Topics and Well Written Essays - 250 words - 32

Writer's choice - Essay Example However, there are other additional measures that can be used in determining the wellbeing. The majority of the areas picked are made of steel (review 350); consequently the heavier the post is, the more it will cost to buy. This shows that steel being heavy is preferred for the placement in the post of cantilever. This expresses that the lightest material of the three empty segments picked above will be the most practical to decide for the for the cantilever post. The rectangular and square blank areas measure the same in this way. This makes them obtain either one will have the same cost, however as the empty rectangular area has a higher component of wellbeing then that will be the most prudent methodology. As I would like to think, this task was done effectively. Most of the sensitive issures were put into consideration. As we decided the best measurements to get the best and most practical component of security for the cantilever post, the three best picked empty segment all have a variable of wellbeing. Over 1.5 which expresses that the undertaking was sufficient. As all the area selected are equipped for supporting the sign, we found that the most prudent empty segment post is discovered to be the "RHS(250 x 150 x 9)". This is as it has a high variable of wellbeing and light

Plantation Economy Essay Example | Topics and Well Written Essays - 2000 words

Plantation Economy - Essay Example (West and Augelli, 1999) The history of Central America is linked with the growth and development of the plantation economy. When the colonialists reached the land, they found enabling climate and they set of establishing plantations to create what came to be known as the sugar kingdom in the history of America. The economy of the region is large reliant on Agriculture. There is production of cash crop like coffee, bananas, sugarcane and cotton which is produced through large holding and most of the products is exported to the Northern American and to Europe. However there is also the growth of subsistence crops like corns, beans, bananas, mains, rice and pulley. In the drier regions there is the production of beef cattle. The large holdings most employee modern farming while the subsistence farmers still use the simple farming techniques that have been in use for along time now. (Wrigley, 1999) Plantation farming has been practiced in the region since the settlement of colonialists in the region. However the region still lags behind in economic development despite producing agricultural products to the world. Has the plantation economy helped the region develop economically or has it helped the investors in the large holdings' This paper represents a well arranged and researched inquisitive essay on the impact of large holding farming in the region. The first part will look at the historical development of the large scale farming over the time and how it has developed in the region. Then it will look at the impact this has been making on the economy of the region and at the end it will look at the present economic situation of these countries so as to make a conclusion of there the plantation economy has been of use to the region of if it has not helped the region. In the conclusion it will look the problem that the region has been facing and what can be done on the situation. Development of plantation economy in the region The historical development of plantation economy in the region dates back when the Spanish colonization was started. With the arrival of Spanish and other colonialist in the region, there was increased development of agrarian economy which was favored by the Amazon climate that extends to the region. When the Spanish came, they immediately stated planting bananas in large plantation around 1860s and by 1870 there was increased growth of banana in the region. Most of the plantations in the region were started along the railway lines which were by then expanding northward to America. When an American entrepreneur was commissioned by the Costa Rica government to build a transition railroad, he started growing bananas along the railway road and immediately began exporting them to United States. Keith was highly successful in the venture and he embarked on the same plantation economic along all other major railway roads that he built. He was able to acquire large tracks of undeveloped la nd and in the process expanded the development of banana plantation to Guatemala and Hondura. In 1869 he merged with Boston Fruit Company and formed the United Fruit Company which rapidly expanded to Central America and by 1955 the company had over 400,000 hectares under production of bananas. (Ferguson, 1998; Mahar and Schneider, 1994) As the colonialists settled there was