Simple nonparametric tests for a known standard survival based on censored data

It is often of interest in survival analysis to test whether the distribution of lifetimes from which the sample under study was derived is the same as a reference distribution. The latter can be specified on the basis of previous studies or on subject matter considerations. In this paper several tests are developed for the above hypothesis, suitable for right-censored observations. The tests are based on modifications of Moses' one-sample limits of some classical two-sample rank tests. The asymptotic distributions of the test statistics are derived, consistency is established for alternatives which are stochastically ordered with respect to the null, and Pitman asymptotic efficiencies are calculated relative to competing tests. Simulated power comparisons are reported. An example is given with data on the survival times of lung cancer patients.     

Robustness of Conditional Moments: An Application to Premium Calculation of Reinsurance Treaties

In this study, the tail probability of a class of distributions commonly used in assessing the severity of insurance losses was examined. Without specifying any particular distribution, the use of an algebraic functional form Cx(-alpha) to approximate the tail behavior of the distributions in the class was demonstrated. Norwegian fire insurance data were examined, and the algebraic functional form was applied to derive the expected loss of a reinsurance treaty that covers all losses exceeding a retention limit. It was shown that (1) the expected loss is insensitive to the parameter alpha for a high retention limit (e.g., a catastrophe treaty), and (2) with a low retention limit (e.g., a largest claim treaty), a reliable estimate of the parameter alpha and a sound judgment on the maximum potential loss of the treaty could provide useful and defensible summary statistics for pricing the treaty. Thus, when dealing with the losses of certain reinsurance treaties, it was concluded that knowledge of a specific probability distribution is not critical, and the summary statistics derived from the model are robust with respect to a large class of loss distributions.     

An algorithm and metric for network decomposition from similarity matrices: Application to positional analysis

We present an algorithm for decomposing a social network into an optimal number of structurally equivalent classes. The k-means method is used to determine the best decomposition of the social network for various numbers of subgroups. The best number of subgroups into which to decompose a network is determined by minimizing the intra-cluster variance of similarity subject to the constraint that the improvement in going to more subgroups is better than a random network would achieve. We also describe a decomposability metric that assesses how closely the derived decomposition approaches an ideal network having only structurally equivalent classes.     

Optimizing Latin hypercube designs by particle swarm

Latin hypercube designs (LHDs) are widely used in many applications. As the number of design points or factors becomes large, the total number of LHDs grows exponentially. The large number of feasible designs makes the search for optimal LHDs a difficult discrete optimization problem. To tackle this problem, we propose a new population-based algorithm named LaPSO that is adapted from the standard particle swarm optimization (PSO) and customized for LHD. Moreover, we accelerate LaPSO via a graphic processing unit (GPU). According to extensive comparisons, the proposed LaPSO is more stable than existing approaches and is capable of improving known results.     

A nonparametric assessment of model adequacy based on Kullback-Leibler divergence

A discrepancy measure to assess model fitness against a nonparametric alternative is proposed. First, a Polya tree prior is constructed so that the centering distribution is the null. Second, the prior is updated in the light of data to obtain the posterior centering distribution as the alternative. Third, a Kullback-Leibler divergence type of test statistic is derived to assess the discrepancy between the two centering distributions. The properties of the test statistic are derived, and a power comparison with several well-known test statistics is conducted. The use of the test statistic is illustrated using network traffic data.     

Sociopolitical Development and Vocational Expectations Among Lower Socioeconomic Status Adolescents of Color

The well‐documented aspiration‐expectation gap refers to lower socioeconomic status (SES) adolescents of color expecting to attain occupations with lower pay and status than the occupations to which they aspire. Sociopolitical inequity, such as structural racism and asymmetrical access to resources, may explain this gap. This article examines the capacity to cope with sociopolitical inequity (i.e., sociopolitical development) and its relationship to vocational expectations among this population. Analyses revealed that sociopolitical development was associated with higher vocational expectations and may contribute to reducing the vocational aspiration‐expectation gap among lower SES adolescents of color. Furthermore, career counseling, guidance, and psychosocial interventions may be augmented by incorporating sociopolitical development.     

Application of the Fuzzy Weighted Average in Strategic Portfolio Management*

We propose a systematic approach that incorporates fuzzy set theory in conjunction with portfolio matrices to assist managers in reaching a better understanding of the overall competitiveness of their business portfolios. Integer linear programming is also accommodated in the proposed integrated approach to help select strategic plans by using the results derived from the previous portfolio analysis and other financial data. The proposed integrated approach is designed from a strategy‐oriented perspective for portfolio management at the corporate level. It has the advantage of dealing with the uncertainty problem of decision makers in doing evaluation, providing a technique that presents the diversity of confidence and optimism levels of decision makers. Furthermore, integer linear programming is used because it offers an effective quantitative method for managers to allocate constrained resources optimally among proposed strategies. An illustration from a real‐world situation demonstrates the integrated approach. Although a particular portfolio matrix model has been adopted in our research, the procedure proposed here can be modified to incorporate other portfolio matrices.     

To Weight or not to Weight: The Role of Domain Importance in Quality of Life Measurement

Although there are problems associated with thepractice of deriving weighted satisfactionscores by multiplying importance ratings andsatisfaction ratings of life domains, theseproblems do not seem sufficient to justify theabandonment of incorporating domain importanceweighting into quality of life (QoL)instruments. This paper shows that domainimportance as a weighting mechanism in QoLinstruments can be conceptually,psychometrically and empirically reasonable. Given the lack of conceptual or theoreticaldevelopment regarding the role of domainimportance in QoL instruments, it is importantto focus our attention on how to weight.     

Optimal estimate of population age structure with varying vital rates

The author presents a method for estimating the age distribution of a population under varying vital statistics. "Some mathematical aspects of the method, as well as its applicability, will be discussed and numerical simulation will be run to illustrate the results and to compare the method with the traditional estimate of stable population theory...."     

论法律语言的意义和作用——自社会语言学跨领域的视角观察

长期以来,整个法律职业所通用的语言,无论是律师和法官在法庭上的用语,抑或是形诸于文字的法条用语,或与当事人权益有切身关系的法律文件的用语,甚至是法学院课堂上的,较之于一般日常生活中所使用的语言,无疑具有相当程度的特殊性。这点可以说是古今中外皆然。自从法律语言学的开山鼻祖DavidMellinkoff教授于上个世纪六十年代,题为TheLanguageoftheLaw(《法律的语言》)一书问世以来,无论是法学界、社会学学界、人类学抑或语言学学界莫不从法律语言学视为具有独立生命力的学科出发,开始重视法律语言的社会地位、功能以及属性。无疑地,正因为法律是一门专业性强、技术性亦高的职业,法律语言也就成了一种具有高度专业性和特殊性的语言,象征着一定的权力和社会地位。但是若试图仅以这点来概括一切,似有见树不见林之憾。本文有鉴于此,不仅立基于传统的社会语言学理论,更试图从“法律论述”(discourseanalysis)理论出发接近该问题,因为“法律论述”关心法律语言作为一种语言变体,其实际运用的场合与情境,牵动着诸多内外在、主客观的因素,一如国外的陪审团审判制度所显示。笔者在本文绪论中提出轮廓之后,接着第二部分再介绍语言的功能和作用并适时引入法律语言。继而第三部分围绕法律语言作为一种“语体”或“语码”(code)或“变体”(variety)的论点,针对诸多相关的社会语言学的复杂因素和理论,进行论述与比较。