International Red Cross Movement

Introduction The International Red Cross Movement is a worldwide organization with a branch in almost all countries across the world. Apparently, the movement is made up of a number of components that include the International Committee of the Red Cross and the International Federation of Red Cross and Red Crescent Societies.Advertising We will write a custom essay sample on International Red Cross Movement specifically for you for only $16.05 $11/page Learn More According to International Red Cross and Red Crescent Movement (1999), there are about 186 National Societies that also form part of the International Red Cross Movement. Arguably, the International Red Cross Movement is the most expansive philanthropic organization that exists in the world today. It is managed by a strong team of qualified staff scattered in different parts of the world. Presently, the operations of the International Red Cross Movement are carried out by approximately 100 indiv iduals comprising of volunteers and staff. Their efforts are augmented by National Societies and collaborating partners in different countries. The movement plays a pivotal role of meeting the needs of the poor, preserving lives and promoting human dignity. Underlying all its operations is the alleviation of poverty and human suffering. Although the different components that make up the International Red Cross Movement are distinct from each other, they work jointly to facilitate the delivery of critical services to the intended beneficiaries. The International Red Cross Movement thus provides a platform for the integration of the different components. History of the International Red Cross Movement The Red Cross Movement began its operations in 1863 under the leadership of Henry Dunant, a businessman of Swiss origin. Disturbed by the suffering that thousands of men left to die after the battle of Solferino in the year 1859, Dunant chose to respond differently. Apparently, these men died as a result of neglect since none of the warring parties could provide help save their lives. Dunant came up with the idea of establishing relief societies not aligned to any particular party to provide assistance to the wounded (British Red Cross, 2014). The relief societies were to consist of volunteers equipped with skills and training to impartially take care of the wounded during times of war. This was later followed by the establishment of the International Committee of the Red Cross in Geneva, Switzerland and the drawing of the Red Cross charter in 1863. Since its establishment in 1863, the movement has been very instrumental in providing assistance to those aggrieved as a result of war or because of different calamities (International Committee of the Red Cross, 2014).Advertising Looking for essay on international relations? Let's see if we can help you! Get your first paper with 15% OFF Learn More Usually, victims of war are forced to flee their homes or countries of birth in order to seek refuge in other countries. They are also made to lose loved ones, property and their dignity. According to the International Committee of the Red Cross (2014), the organization accomplishes its objectives through direct involvement in issues that affect humanity across the world and by promoting the formation of laws that uphold human dignity. Structure At the very top, the International Red Cross Movement consists of an Assembly and an Assembly Council. The Assembly Council is a subsidiary of the Assembly with certain powers delegated to it (International Committee of the Red Cross, 2014). The top leadership also includes a Directorate which is the executive body of the movement and ensures a smooth running of the organization’s affairs. The Directorate acts under the guidance of the Assembly and the Assembly Council as may be appropriate. The Assembly and the Assembly Council are chaired by the President of the International Committee of the Red Cross assisted by a Vice President. The Directorate on the other hand is made up of five members and is chaired by the Director General. Issues that relate to policy formulation, strategy and decision making regarding the development of international humanitarian laws are all handled by the Assembly and the Assembly Council. The Assembly also controls what is done by the Assembly Council and the Directorate. Effectiveness of the International Red Cross Movement Over the years, the International Red Cross Movement has touched the lives of many victims of war, natural disasters as well as criminal activities across the world. In the United States, a number of states have been hit by natural disasters and the Red Cross movement has been instrumental in helping the affected to rebuild their lives after the calamities. Many other parts of the world have also benefited from the activities of the International Red Cross Movement including war torn places in Africa. The conflict in South Sudan, for example, has left scores of people homeless and many have been forced to flee to neighboring countries. With help from supporters, the International Red Cross Movement has already provided support to many who have been affected. In solidarity, the British Red Cross pledged a substantial amount of money to facilitate the operations of the International Red Cross Movement. The efforts that have been made by the International Red Cross Movement can not be underestimated. While it might take the government too long to respond to an emergency situation, all that the International Red Cross Movement needs to know is that there is a need somewhere and without wasting time, specialized teams of volunteers and experts will be on the ground working hard to restore normalcy.Advertising We will write a custom essay sample on International Red Cross Movement specifically for you for only $16.05 $11/page Learn More On many occasions, the movement ha s been involved in working closely with victims and ensuring that they are able to stand on their own before leaving. Reasons of Effectiveness The effectiveness of the International Red Cross Movement can be attributed to a number of reasons. One of the greatest strengths of the International Red Cross Movement is its commitment to offering voluntary services. According to the tenets of the International Red Cross Movement, nothing matters more than preserving lives. While money plays a big role for some humanitarian organizations, service to humanity is critical for the International Red Cross Movement. Another reason for its effectiveness has to do with the fact that all members of the movement are required to subscribe to a strict code of conduct. Adherence to the code of conduct enables all players to behave appropriately when called upon to deal with an emergency. The code of conduct clearly stipulates that delivery of services to the affected must be in accordance with the req uirements of the international humanitarian law. Though voluntary, organizations that subscribe to the code of conduct are expected to enforce its application in their various operations. The International Red Cross Movement has also succeeded because of the huge support received from collaborating partners and well wishers. Organizations and individuals across the world recognize the efforts of the Red Cross Movement to protect the interests of the less fortunate (International Federation of Red Cross and Red Crescent Societies, 2011). By working closely with such organizations, the International Red Cross Movement is able to finance its operations without much struggle and as a result, provide essential services to the needy. Ordinarily, assistance may be in kind or in monetary form. Effectiveness of the movement’s operations is also as a result of being transparent and accountable in running its affairs. Certainly, failure to account for resources has a very negative impac t on charitable work. On the other hand, both transparency and accountability encourage sponsors to continue with their acts of philanthropy by supporting the activities of the International Red Cross Movement.Advertising Looking for essay on international relations? Let's see if we can help you! Get your first paper with 15% OFF Learn More As part of its transparency policy, the organization allows sponsors to visit any project they are supporting. In case a sponsor has given substantial contribution towards a project and he or she wishes to visit, it is possible for the Red Cross Movement to make arrangements for this to happen. The need for accountability has thus played a very big role in ensuring that the International Res Cross Movement is effective in its operations. The International Red Cross Movement also benefits greatly from its huge pool of volunteers. Usually, the cost of maintain volunteers is reasonable and does not place a heavy financial burden on the organization. While volunteers benefit from the world class training offered by the Red Cross Movement as well as an opportunity to get experience in offering humanitarian services, the International Red Cross Movement manages to get its work done much faster because of the huge population of volunteers at its disposal. The relationship between the Red C ross Movement and the volunteers is thus mutually beneficial. To ensure that volunteers deliver as expected, they are taken through a vigorous training that includes understanding the tenets that govern the operations of the International Red Cross Movement. The principles that are used to provide guidance include respect for humanity, upholding the spirit of impartiality, remaining neutral when offering services to the afflicted, independence, voluntary service, unity, and universality. Due to the number of disasters that the International Red Cross Movement has to deal with, staff and employees are often prepared to respond swiftly in most emergencies. Professionals and volunteers who work for the movement are also constantly engaged in research to understand how to deal with calamities or emergency situations. Normally, they would focus on strategies that help in predicting hazards, assessment of the environment in order to single out vulnerable areas and communities that may be seriously affected in case of a disaster. The International Red Cross Movement is also involved in advocacy activities aimed at ensuring that the world is a better place for everyone to live in. Global Performance of the International Red Cross Movement The International Red Cross Movement has a presence in most countries across the world and its determination to save humanity has received praise from many beneficiaries. Despite being scattered globally, the various representatives of the International Red Cross Movement in different countries pull resources together to provide a solution in the event that a disaster occurs anywhere in the world. Because of the movement’s global presence and elaborate network of collaborators, it is often easy to get organized and act when disaster strikes. Generally, the International Red Cross Movement stands from other humanitarian organizations because of its dedication and selflessness to fight for the rights of the disadvantaged in the society. All over the world, the International Red Cross Movement has been working alongside other humanitarian organizations to preserve life and to uphold respect for humanity. According to Global Road Safety Partnership (2014), a world disasters report released in 1998 indicated that the International Federation of Red Cross and Red Crescent, a component of the International Red Cross Movement, was the first to talk about the global effect of road carnage. As a result of the intervention by the International Federation of Red Cross and Red Crescent, the World Bank and the British Department for International Development (DFID), formed the Global Road Safety Partnership. The creation of the Global Road Safety Partnership opened an avenue that brought together stakeholders from government and civil society to devise strategies of addressing road carnage issues. This is a very clear indication of how the International Red Cross Movement influences decision makers on behalf of many o thers who may not be in a position to do so. As pointed out earlier, the International Red Cross Movement has for a very long time been involved in influencing the formulation of policies that uphold human dignity. Often, the needs of the less fortunate in the society are neglected in various levels of government. As such, policies that are developed by government officials do not recognize their needs. By cooperating with other international humanitarian organizations, the International Red Cross Movement has been able to spearhead the formulation of laws and policies that are inclusive and demonstrate respect for humanity. According to the International Committee of Red Cross (2010), the growing number of armed conflicts across the world presents a serious challenge to the work of the International Red Cross Movement. Unfortunately, conflicts arise and continue for a very long time without a definite end. Certainly, the responsibility of caring for those affected becomes strenuous both emotionally and financially to those involved in offering help. The conflicts that have been experienced in the Middle East and many other parts of Africa are a clear example of how involving the work of the International Red Cross Movement can be. The International Committee of the Red Cross (2010) also postulates that the emergence of new challenges such as environmental degradation and effects of climate change will compel the International Red Cross Movement to create new partnerships, widen its networks and have a very strong presence in different countries. Conclusion The challenges faced in various parts of the world today require a proactive approach by humanitarian organizations. Natural calamities, civil wars, climatic changes and acts of terrorism are all responsible for destabilizing the society in one way or another. Victims may end up dying, displaced or becoming refugees in foreign countries. The role of the International Red Cross Movement is thus very critical in supporting the affected. Although governments make attempts to assist the afflicted, the help often comes in late or may sometimes be insufficient to fully address the problem at hand. By working closely with well wishers and volunteers, the International Red Cross Movement always endeavors to provide the much needed support without showing favoritism. To ensure effectiveness in service delivery to the affected, the International Red Cross Movement works with professionals to predict hazards and understand the ability of vulnerable groups in the event of a disaster. Effectiveness of the International Red Cross Movement is further reinforced by having a strict code of conduct that member organizations have to subscribe to. The movement also promotes a high level of transparency and accountability which motivate supporters. References British Red Cross. (2014). The beginning of the Red Cross Movement. Web. Global Road Safety Partnership. (2014). International Federation of Red Cro ss and Red Crescent Societies. Web. International Committee of the Red Cross. (2010). ICRC Strategy 2011-2014: Achieving Significant Results for People in Need. Web. International Committee of the Red Cross. (2014). History of the ICRC. Web. International Federation of Red Cross and Red Crescent Societies (IFRC). (2011). Red Cross Red Crescent Perspective on Aid Effectiveness. Web. International Red Cross and Red Crescent Movement. (1999). Red Cross and Red Crescent History. Web. This essay on International Red Cross Movement was written and submitted by user Aubrey Goff to help you with your own studies. You are free to use it for research and reference purposes in order to write your own paper; however, you must cite it accordingly. You can donate your paper here.

Hypothesis Test for Comparing Two Proportions

Hypothesis Test for Comparing Two Proportions In this article we will go through the steps necessary to perform a hypothesis test, or test of significance, for the difference of two population proportions.  This allows us to compare two unknown proportions and infer if they are not equal to each other or if one is greater than another. Hypothesis Test Overview and Background Before we go into the specifics of our hypothesis test, we will look at the framework of hypothesis tests.  In a test of significance we attempt to show that a statement concerning the value of a population  parameter (or sometimes the nature of the population itself) is likely to be true.   We amass evidence for this statement by conducting a statistical sample.  We calculate a statistic from this sample.  The value of this statistic is what we use to determine the truth of the original statement.  This process contains uncertainty, however we are able to quantify this uncertainty The overall process for a hypothesis test is given by the list below: Make sure that the conditions that are necessary for our test are satisfied.Clearly state the null and alternative hypotheses. The alternative hypothesis may involve a one-sided or a two-sided test.  We should also determine the level of significance, which will be denoted by the Greek letter alpha.Calculate the test statistic. The type of statistic that we use depends upon the particular test that we are conducting.  The calculation relies upon our statistical sample.  Calculate the p-value. The test statistic can be translated into a p-value.  A p-value is the probability of chance alone producing the value of our test statistic under the assumption that the null hypothesis is true. The overall rule is that the smaller the p-value, the greater the evidence against the null hypothesis.Draw a conclusion. Finally we use the value of alpha that was already selected as a threshold value.  The decision rule is that If the p-value is less than or equal to alpha, then we reject t he null hypothesis. Otherwise we fail to reject the null hypothesis. Now that we have seen the framework for a hypothesis test, we will see the specifics for a hypothesis test for the difference of two population proportions.   The Conditions A hypothesis test for the difference of two population proportions requires that the following conditions are met:   We have two simple random samples from large populations.  Here large means that the population is at least 20 times larger than the size of the sample. The sample sizes will be denoted by n1 and n2.The individuals in our samples have been chosen independently of one another.  The populations themselves must also be independent.There are at least 10 successes and 10 failures in both of our samples. As long as these conditions have been satisfied, we can continue with our hypothesis test. The Null and Alternative Hypotheses Now we need to consider the hypotheses for our test of significance.  The null hypothesis is our statement of no effect.  In this particular type of hypothesis test our null hypothesis is that there is no difference between the two population proportions.  We can write this as H0: p1 p2. The alternative hypothesis is one of three possibilities, depending upon the specifics of what we are testing for:   Ha:  p1 is greater than p2. This is a one-tailed or one-sided test.Ha: p1 is less than p2. This is also one-sided test.Ha: p1 is not equal to p2. This is a two-tailed or two-sided test. As always, in order to be cautious, we should use the two-sided alternative hypothesis if we do not have a direction in mind before we obtain our sample.  The reason for doing this is that it is harder to reject the null hypothesis with a two-sided test. The three hypotheses can be rewritten by stating how p1 - p2 is related to the value zero.  To be more specific, the null hypothesis would become H0:p1 - p2 0.  The potential alternative hypotheses would be written as: Ha:  p1 - p2   0 is equivalent to the statement p1 is greater than p2.Ha:  p1 - p2  Ã‚  0 is equivalent to the statement p1 is less than p2.Ha:  p1 - p2  Ã‚  Ã¢â€°   0 is equivalent to  the statement p1 is not equal to p2. This equivalent formulation actually shows us a little bit more of what is happening behind the scenes.  What we are doing in this hypothesis test is turning the two parameters p1 and p2  into the single parameter p1 - p2.  We then test this new parameter against the value zero.   The Test Statistic The formula for the test statistic is given in the image above.  Ã‚  An explanation of each of the terms follows: The sample from the first population has size n1.  The number of successes from this sample (which is not directly seen in the formula above) is k1. The sample from the second population has size n2.  The number of successes from this sample is k2.The sample proportions are  p1-hat k1 / n1  and p2-hat   k2 / n2 .We then combine or pool the successes from both of these samples and obtain:  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   p-hat ( k1 k2) / ( n1 n2). As always, be careful with order of operations when calculating.  Everything underneath the radical must be calculated before taking  the square root. The P-Value The next step is to calculate the p-value that corresponds to our test statistic. We use a standard normal distribution for our statistic and consult a table of values or use statistical software.   The details of our p-value calculation depend upon the alternative hypothesis we are using: For Ha: p1 - p2   0, we calculate the proportion of the normal distribution that is greater than Z.For Ha: p1 - p2  Ã‚  0, we calculate the proportion of the normal distribution that is less than Z.For Ha: p1 - p2  Ã‚  Ã¢â€°   0, we calculate the proportion of the normal distribution that is greater than |Z|, the absolute value of Z.  After this, to account for the fact that we have a two-tailed test, we double the proportion.   Decision Rule Now we make a decision on whether to reject the null hypothesis (and thereby accept the alternative), or to fail to reject the null hypothesis.  We make this decision by comparing our p-value to the level of significance alpha. If the p-value is less than or equal to alpha, then we reject the null hypothesis. This means that we have a statistically significant result and that we are going to accept the alternative hypothesis.If the p-value is greater than alpha, then we fail to reject the null hypothesis. This does not prove that the null hypothesis is true. Instead it means that we did not obtain convincing enough evidence to reject the null hypothesis.   Special Note The confidence interval for the difference of two population proportions does not pool the successes, whereas the hypothesis test does.  The reason for this is that our null hypothesis assumes that p1 - p2 0.  The confidence interval does not assume this.  Some statisticians do not pool the successes for this hypothesis test, and instead use a slightly modified version of the above test statistic.

Research paper (predicting the number of internet users) Essay

Research paper (predicting the number of internet users) - Essay Example Ethically, sharing of data for other purposes other than the intended is un-ethical (Callahan 1998) To get a best predictor of the number of internet users, the researcher used multivariate linear regression. In this type of methodology, each of the predictor variable is modelled against the response variable, in this case the number of internet users. This process is carried over with different combinations of the explanatory variables and the values of R, coefficient of correlation, and R2, coefficient of determination for the different models are calculated. The model with the highest value of R is normally selected as the best fitting model for the data (Bryman 1992). R2 explains the variations in the response variable readings. In this case, the researcher used all the explanatory variables in the initial model and used the backwards which eliminates the variables which are not better placed to explain the response variable as anticipated. The only problem with this technique is that it may result in the elimination of explanatory variables even before their effects on the entire model have been determined. As a best practice, I suggest individual simple regression equations to determine the individual effects on the response variable and then stepwise inclusion of the variables (Hinton 1995).

Gun control Research Paper Example | Topics and Well Written Essays - 1500 words - 5

Gun control - Research Paper Example Many cases of gun related crimes and fatalities have been reported within the country which indicates that public access to guns may be more harmful that beneficial. In this way, the society should understand the important of gun control laws and limiting access to citizens that access guns while addressing arguments opposing them as a way of saving lives. Gun violence is a common phenomenon in the American society and the National Victimization Survey showed that 467, 321 people died in 2011 as a result of criminal activities using firearms. The FBI generated a report in 2011 that testified that 68% of homicides and 41% of violent robberies as well as 21% of aggravated attacks are done using guns. In addition, hand guns are the most common firearms that are used in criminal activities especially homicides committed each year. This research shows that gun violent is a reality within the society and many people use them to intimidate victims. It is also clear that most hand guns are involved in criminal activities like assault, in various threats that are done without injury, and in many cases of rape or robbery (Zimring 723). Gun ownership is another apparent issue in the United States with findings showing that more than 200 million firearms were in private ownership in the 1990s. Through the years guns among private ownership have increased especially due to creation of new households and more wealthy people who needed to acquire firearms. In other areas, the increasing crime rates within the country motivated citizens who initially did not have guns to acquire them in a bid to seek protection. It is evident however that the reason that people own guns is more related to crime rates compared to having more wealth. Nonetheless, it is also evident that many firearms, specifically the long guns are acquired for recreational activities like hunting which is not related to

Marketing strategy of Starbucks Essay Example | Topics and Well Written Essays - 1000 words

Marketing strategy of Starbucks - Essay Example Starbucks is attempting to involve its customers in the product in many ways. First, the company is marketed as a status item hence it is high involvement (has higher psychological, economic, and social risk) cheaper coffee or unbranded coffee from its competitors. Secondly, Starbucks is utilizing different campaign, like â€Å"Bold Coffee† campaign and the â€Å"Via† taste challenge so as to get its customers to come to the store continuously and try the new products. This is a perfect use of the buyer behavior theory that predicts that the customers could switch brands only to try a new thing. Offering its customers with a new flavor to try every week, the company actively manages the natural inclination of the customers to try new things. These strategies together with emphasizing on socially responsible behavior, the company are also offering customers with additional benefits on which they can evaluate its products. Through building a strong brand that its customer s are loyal to, implying that the customers don’t even consider the other brands whenever they are going for coffee, immediately they will choose Starbucks since it’s the coffee for any person who loves coffee. These are the strategies that are employed by Starbucks to keep its existing customers satisfied (Simon, B. 2009). Promotion is the most common promotional mix elements utilized by Starbucks are internet marketing, advertising, public relations, personal selling, and sales promotion (Michelli, J. A. 2007).

History Of Weibull Distribution

History Of Weibull Distribution In probability theory and statistics, the Weibull distribution is one of the most important continuous probability distributions. It was, first introduced by W. Weibull in 1939 when he was studying the issue of structural strength and life data analysis, and was formally named after him later in 1951. He proposed the chain model to explain the structural strength. Based on the assumption that a structure is composed of several small components (n pieces) in series, we could consider the structure as being composed of an n-rings chain, the strength of which (or life) completely depends on the weakest rings strength (or life). In his model, with the assumption that the strength of different rings are independent and identically distributed, finding the strength distribution of the chain become the problem of finding the distribution of the weakest ring. Due to the result of research conducted by Gnedenko (1943), no matter what the original distribution of the variable is, the asymptotic distribution of the minimum could only be three different forms. The Weibull distribution is one of them. Since Weibull distribution is established on the weakest link model, which could sufficiently reflect the defect of material and the effects of stress concentration, it has been considered as appropriate model to describe strength of fiber material in practical application. 1.2 Stress-Strength Analysis Stress-Strength Analysis is the analysis of the survival of materials subjected to a random stress. Stress-Strength Analysis is a commonly used tool in reliability engineering. The stress-strength reliability is given by Where is the pdf of the strength distribution and is the cumulative distribution function of the stress distribution. In this case, the data for the strength set would be actual data that is indicative of the strength of the material (i.e. maximum applied stress to cause failure), and the stress data would be actual stress data of the material under use conditions. 1.3 Research Motivation Target Judging from physical of carbon fibers, microscopic flaws cause tensile failure to occur below the intrinsic strength of the fiber. Therefore, analysis of tensile failure data should provide insight into the distribution of flaws within fiber. The fiber might be viewed as a chain of interlocking links, with the flaws acting as weak links in the chain. As the same model mentioned previously, the chain will fail at its weakest link. Usually tensile data do not confirm to rigid statistical distributions. Therefore, they cannot be represented by the specific fixed statistical distribution accurately. Instead, it is necessary to use a flexible distribution that enables the shape of the distribution function to be altered by the data itself. Under this situation, the Weibull distribution is one the natural choice.[] Although based on the theoretical model, Weibull distribution should be an appropriate description strength distribution for carbon fibers. However, judging from empirical data, it always suggests that the Weibull distribution is not an appropriate model for carbon fibers. One plausible problem is validity of independency assumption in the chain of links model. In that model, we assume a physical system is consisted of n identical units or items connected in series and each unit should be independently and identically distributed. However, in practice, this strict assumption cannot be guaranteed, which will cause the discrepancy of between real strength and Weibull distribution. For example, if there is a defect hole on n-th link, this defect hole will probably expend to adjacent link(n-1-th and n+1-th). That causes the problem of dependency. Another popular plausible explanation is clamp effects which is analysed in detail by Phoenix and Sexsmith[]. In building upon this work, Stoner[] developed new end-effect Weibull model, in which distinct Weibull distributions were used to characterize failures from true flaws and from artifacts in carbon fibers. Although, to some extent, the end-effect Weibull model accurately descripts the data upon which it was based, it provokes our interests in pre-stress issue applied on carbon fiber before it got tested. Because in practice, such as in the strength test, fiber always suffer stress before they can be tested. For example, in the popular experiment proposed by Bader Pries[], there is no guaranty that single fiber could be distinguished without any slight press of damage. Thus, in that experiment, they stress the fibers before they get tested, which will cause the strength test result representing all fibers performance survived from pre-stress. This question arise our interest in study of pre-stress Weibull distribution. In the problem we will discuss in this thesis, we assume that original strength of fiber is Weibull distributed. Therefore, if there is no pre-stress applied on fiber material, the final strength will be also Weibull distributed without any changes from origins. However, judging from common sense, pre-stress could not be avoided exclusively before the strength test. They usually could occur in shipping procedure, and pre-test preparation procedure. Our goal is to find out under what conditions these pre-stressed fiber have a (approximately) Weibull distribution. In the second chapter, the results of survival fiber strength distribution under multi-type pre-stressed condition have been given out. At same time, a minimum censoring proportion has been set up to assure the pre-stress has a significant effect on original fiber material. In the third chapter, MSE is used to measure the fitness of the pre-stressed censored sample and nearest Weibull distribution. Moreover, we discuss the goodness of fit test applied to the pre-stressed censored sample and Weibull distribution with parameters value equal to MLEs from censored sample, which is considered as nearest Weibull distribution based on the censored sample. In the fourth chapter, the simulation results of two methods proposed in the third chapter have been discussed and analyzed. Finally, we will give out a conclusion about survival distribution of pre-stress Weibull distribution. Chapter 2 Weibull Family and Pre-Stressed Censored Sample 2.1 Basic Properties of Weibull Distribution The probability density function of a Weibull random variable is The parameter is the shape parameter, is the scale parameter, and is the location parameter of the distribution. When , this reduces to the usual two-parameter Weibull distribution. The Weibull distribution is related to many other probability distributions; in particular, it interpolates between the exponential distribution () and the Rayleigh distribution (). The CDF The cumulative distribution function for the two parameter Weibull distribution is for , and for . The failure rate (or hazard rate) is given by: The Mean The mean, , of Weibull pdf is given by: Where is the gamma function evaluated at the value of . The Median The median, , is given by: The Mode The mode, , is given by: The Standard Deviation The standard deviation, is given by: Applications The Weibull distribution has multiple applications in practical world. Survival analysis Reliability engineering Weather forecasting General insurance 2.2 Censored Weibull Sample Because our primary interest is to study strength distribution of fiber material after pre-stressed, we need to generate various censored Weibull sample which is applied multi-type pre-stress. Given and are independent random variables where represent original strength of material and pre-strength individually. So the problem of our interest is what distribution does variable have? To state the problem more clearly, we assume the original strength of material always yield to Weibull distribution family. And the pre-stress yield to three different distribution families which are Weibull, Normal and Gamma. Based on different parameter choice, we will try to find out what values of the parameters give us that survival strength yield to or approximately yield to Weibull distribution. Mentioned in Chapter 1, we assume is weibull distributed with different shape and scale parameter. In this paper, we will from (pre-stress variable) from three different distribution: Weibull distribution, Gamma distribution, and Normal distribution. Also as similar as original strength set, in each distribution option, different parameters are chosen to generate various censored Weibull sample. Meanwhile, since trivial results are not what we expected, a certain censoring ratio has been set up to guarantee there is a significant effect of pre-stress applied on original fiber carbon material. Serving to this purpose, samples with censoring proportion is 0.5 or greater than 0.5 will be kept, which is considered as plausible limit of censoring ratio. Chapter 3 Mean Squared Error and Goodness of Fit Test The Mean Squared Error (MSE) is a measure of how close fitted curve is to data points. For every data point, the vertical distance from the point to the corresponding value on the fitted curve (the error) will be taken, and the value will be squared. Then those squared values have been added up for all data points, and been divided by the number of points, which is considered as a mean. Since all errors have been switched into positive values on matter what original sign they have, negative values do not cancel positive values. The smaller the Mean Squared Error, the closer the fit curve is to the data points. MSE has been widely used for quantitative performance metric in the field of statistical regression and engineering, such as signal processing. 3.1 Comparison of MSE of Censored Weibull Sample Based on the censored Weibull Sample we got, we will calculate out MLE of parameters for Weibull distribution, noted as and , which is considered as nearest Weibull distribution to censored weibull sample. Since our objective is to measure fitness of censored Weibull sample and nearest Weibull distribution, MSE between of censored Weibull sample and Weibull distribution with parameters and . We establish the MSE as following way: Where are censored Weibull sample which is sorted as . is empirical CDF at sample point . is defined as sample size. And is CDF of Weibull distribution with parameter , which is MLEs got based on censored Weibull sample. In addition, a baseline of MSE comparison is established by calculating MSE between the sample of size from Weibull() and Weibull() distribution. Where consist the sample of size from Weibull(), which is sorted as ascending order: . is empirical CDF at sample point . And is CDF of Weibull distribution with parameter . 3.2 Comparison via Simulation Result We conducted a large-scale simulation study to compare of the performance of difference between base MSE and sample MSE depends on different censoring stress distribution and parameter chosen. For example, let original strength distribution yields to Weibull(1,1), and censoring stress distribution is Gamma distribution with parameter value chosen from the range 0.25 to 2.5, then we will focus on the performance of fitness of cersored sample to Weibull distribution from various aspects such as censoring proportion, shape parameter value of censoring distribution and scale parameter value of censoring distribution. From above figure, we could not hardly see that the MSE increases with increasing of cersoring proportion, which could be simply interpreted as survival data will go off the original strength distribution when considerable proportion of original strength failed the pre-stress test. Meanwhile, the base MSE keeps relatively stable, since it will not be affected by different pre-stress distribution. Therefore, it is obvious to tell that difference between MSE and base MSE is raised up when the censoring proportion increases, which indicates fitness will go worse at same time. The series of comparison MSE chart are arranged by the ascending order of value of Shape Parameter of Gamma Distribution. If we focus on the changing trend of Average Difference between Sample MSE and Base MSE, we could easily figure out that the Average Difference decreases as long as value of shape parameter become smaller and smaller. This shows that fitness of sample is improved by using smaller shape parameter of pre-stress Gamma distribution. On the other side, if we focus on each individual chart, it is not too hard to find that when the value of Scale increases, difference between Sample MSE and Baseline decreases, which indicates fitness is improved by larger scale parameter chosen. This phenomenon could be interpreted as larger scale brings in less spread compared with smaller ones create absolute peak in pdf, which breaks the continuity of censored sample. Above figure is overall behavior of MSE based on different choice of shape and scale parameter of pre-stress gamma distribution. To summary up, In general MSE boosts up where is smaller scale value and larger shape values. Fitness performance indicates censored sample is still Weibull (or approximately Weibull) distributed when shape and scale parameter choice close to minimum and maximum individually. Chapter 4 Fit Study Based on Weibull Goodness-of-Fit Tests In order to study whether the censored weibull distribution data yields to a weibull distribution, we first generate different censored weibull samples based on different censoring function. Then we use the weibull distribution with parameters value equal to MLE of censored sample as hypothesis. Three Goodness-of-Fit Tests are manipulated to censored weibull samples. We check whether simulation results shows censored weibull sample still yields to a weibull distribution. Goodness-of-fit tests Goodness-of-fit tests for the two-parameter Weibull distributions have drawn considerable attention since its critical importance. Mann and others (1973), Smith and Bain (1976), Stephens (1977), Littell and others (1979), Chandra and others (1981), Tiku and Singh (1981), Wozniak and Warren (1984), and James and others (1989) have gave out universal discussion of this problem. Mann and others (1973) and Tiku and Singh (1981) proposed new statistics to test the goodness-of-fit of two-parameter Weibull distribution. ), Smith and Bain (1976) proposed a test statistic to test normality which is analogous to the Shapiro-Francis statistic. The Smith and Bain statistic was derived from the sample correlation between the order statistics of a sample and the expected value of the order statistics under the assumption that the sample comes from a two-parameter Weibull distribution. They provided critical values for samples containing 8, 20, 40, 60, 80 observations. Stephens (1977) provided tabl es of the asymptotic critical values of the Anderson-Darling statistic and the Cramer-von Mises statistic for various significance levels. Littell and others (1979) made a comparison among the Mann, Scheuer, and Fertig statistic, the Smith and Bain statistic, the modified Kolmogorov-Smirnov statistic, the modified Anderson-Darling statistic, and the modified Cramer-von Mises statistics through a various of power studies for sample size n = 10 to 40. Critical values for the , , and statistics for n = 10 to 40 have been calculated and provided at the same time. Chandra and others (1981) calculated critical values for the Kolmogorov-Smirnov statistic for n = 10, 20, 50 and infinity for three situations. James and others produced extensive tables of goodness-of-fit critical values for the two parameter Weibull distributions developed through simulation for the Kolmogorov-Smirnov statistic, the Anderson-Darling statistic, and Shapiro-Wilk-type correlation statistics. Kolmogorov-Smirnov statistic Kolmogorov-Smirnov test (Chakravart, Laha, and Roy, 1967) is widely used for comparing a sample with a reference probability distribution (one-sample K-S test), or for comparing two samples (two-sample K-S test). Since it is highly sensitive to distinguish the difference of the empirical cumulative distribution functions of the tested samples, it has been considered as one of the most useful nonparametric methods for comparing two samples. Kolomogorov-Smirnov test is based on the distance between the empirical distribution function of the sample and the cumulative distribution function of the reference distribution, or between the two samples empirical distribution functions. Kolmogorov-Smirnov test has been modified to serve as a goodness of fit test here. The modified Komogorov-Smirnov D statistic is given by where is the empirical distribution function of the sample and is the fitted distribution. Anderson-Darling statistic Anderson-Darling test (Stephens, 1974) is used to test whether the data follow a particular distribution. It is named after Theodore Wilbur Anderson and Donald A. Darling who proposed it in 1952. Anderson-Darling test is based on Kolmogorov-Smirnov test and enjoys superior property of more sensitive due to specific distribution application in calculating critical values. Contrarily, its disadvantage is that critical values must be calculated for each distribution. Anderson-Darling test has been modified to serve as a goodness of fit test here. The modified Anderson-Darling statistic is given by Where and is the th-order statistic. Shapiro-Wilk-Type correlation statistics In statistics, the Shapiro-Wilk test is used as the tester of goodness-of-fit test of normal distribution. It has the superior power compared with other statistics in detecting the data comes from a relatively wide range of other distributions for testing goodness-of-fit of normal distributions which has been proposed from Monte-Carlo study of Shapiro and others (1968). Shapiro-Wilk test has been modified to serve as a goodness of fit test here. The statistic first proposed by Shapiro and Francia (1972) but with approximate scores suggested by Filliben (1975) and modified form fitting for good-of-fit test for Weibull distributions is given by: And Is the median score, in the spirit of Filliben, except that these scores depend upon the maximum likelihood estimate the Weibull shape parameter . If a variable has the two-parameter Weibull distribution, the variable has an extreme value distribution. Calculating goodness-of-fit on this scale has advantages. Since the extreme value distributions are defined by location and scale parameters, the critical values for the correlation statistic are not dependent on the true shape parameter. Thus, for two-parameter Weibull distribution, we propose the correlation-type statistic , where And Simulation Result

Community Service :: essays research papers

When people hear how many hours of community service I have done, they ask, "Do you get paid?" When I say no, they wonder why I do it. I tell them it's because I like to help people. Many think that community service is just something you are forced to do for school. To me, community service is a way of giving back. I like making people feel as though they matter, and it gives me a warm feeling at the end of the day because I feel I have made a difference. I grow as a person each time I do community service. Some people do community service because they have to, but I do it because I want to. I have volunteered over 300 hours of community service at a local elementary. I helped children complete their homework assignments and spend quality time with them while their parents work late. I read to the children and played with them when their parents do not have the time. For the past three years, I have assisted the adult volunteers at the After School Care program at Parkview Elementary. My main supervisor was Mrs. King. This program is one in which, parents can leave their children supervised by adults while they work late. I was assigned a group of 10 children, between the ages of 5-11. I volunteered two hours every weekday, tutoring and mentoring my group. The first week was a little awkward. I did not know any of the kids or what to talk to them about. Mrs. King asked me to help them tie their shoes. So, one by one, they came into the hallway and I helped them with their shoes. This gave me the opportunity to talk to them just one-on-one and see what they were like. It was great! They were very friendly and talkative. Since I began in November 2000, I have been going every weekday until my mission was accomplished in December 2001. I have worked with them on completing their homework, reading books, and many different things. It has been a great experience for me. Every time I see my students, they always say hi and I receive many hugs. They make me feel extremely important just being with them. I am a significant role model and a great influence for these growing children. I love helping out students and teachers. I wish everyone had the chance to do a project like this and see how much fun it is. Community Service :: essays research papers When people hear how many hours of community service I have done, they ask, "Do you get paid?" When I say no, they wonder why I do it. I tell them it's because I like to help people. Many think that community service is just something you are forced to do for school. To me, community service is a way of giving back. I like making people feel as though they matter, and it gives me a warm feeling at the end of the day because I feel I have made a difference. I grow as a person each time I do community service. Some people do community service because they have to, but I do it because I want to. I have volunteered over 300 hours of community service at a local elementary. I helped children complete their homework assignments and spend quality time with them while their parents work late. I read to the children and played with them when their parents do not have the time. For the past three years, I have assisted the adult volunteers at the After School Care program at Parkview Elementary. My main supervisor was Mrs. King. This program is one in which, parents can leave their children supervised by adults while they work late. I was assigned a group of 10 children, between the ages of 5-11. I volunteered two hours every weekday, tutoring and mentoring my group. The first week was a little awkward. I did not know any of the kids or what to talk to them about. Mrs. King asked me to help them tie their shoes. So, one by one, they came into the hallway and I helped them with their shoes. This gave me the opportunity to talk to them just one-on-one and see what they were like. It was great! They were very friendly and talkative. Since I began in November 2000, I have been going every weekday until my mission was accomplished in December 2001. I have worked with them on completing their homework, reading books, and many different things. It has been a great experience for me. Every time I see my students, they always say hi and I receive many hugs. They make me feel extremely important just being with them. I am a significant role model and a great influence for these growing children. I love helping out students and teachers. I wish everyone had the chance to do a project like this and see how much fun it is.