Data skeletons: simultaneous estimation of multiple quantiles for massive streaming datasets with applications to density estimation

We consider the problem of density estimation when the data is in the form of a continuous stream with no fixed length. In this setting, implementations of the usual methods of density estimation such as kernel density estimation are problematic. We propose a method of density estimation for massive datasets that is based upon taking the derivative of a smooth curve that has been fit through a set of quantile estimates. To achieve this, a low-storage, single-pass, sequential method is proposed for simultaneous estimation of multiple quantiles for massive datasets that form the basis of this method of density estimation. For comparison, we also consider a sequential kernel density estimator. The proposed methods are shown through simulation study to perform well and to have several distinct advantages over existing methods.     

Predictive Bayesian Microbial Dose-Response Assessment Based on Suggested Self-Organization in Primary Illness Response: Cryptosporidium parvum

The probability of illness caused by very low doses of pathogens cannot generally be tested due to the numbers of subjects that would be needed, though such assessments of illness dose response are needed to evaluate drinking water standards. A predictive Bayesian dose-response assessment method was proposed previously to assess the unconditional probability of illness from available information and avoid the inconsistencies of confidence-based approaches. However, the method uses knowledge of the conditional dose-response form, and this form is not well established for the illness endpoint. A conditional parametric dose-response function for gastroenteric illness is proposed here based on simple numerical models of self-organized host-pathogen systems and probabilistic arguments. In the models, illnesses terminate when the host evolves by processes of natural selection to a self-organized critical value of wellness. A generalized beta-Poisson illness dose-response form emerges for the population as a whole. Use of this form is demonstrated in a predictive Bayesian dose-response assessment for cryptosporidiosis. Results suggest that a maximum allowable dose of 5.0 x 10(-7) oocysts/exposure (e.g., 2.5 x 10(-7) oocysts/L water) would correspond with the original goals of the U.S. Environmental Protection Agency Surface Water Treatment Rule, considering only primary illnesses resulting from Poisson-distributed pathogen counts. This estimate should be revised to account for non-Poisson distributions of Cryptosporidium parvum in drinking water and total response, considering secondary illness propagation in the population.     

General Job Satisfaction From a Developmental Perspective: Exploring Choice—Job Matches at Two Career Stages

The authors explored predictions of general job satisfaction at early and middle adulthood and uncovered several findings about developmental processes associated with job satisfaction. Tests of life‐span career theory propositions revealed that neither choice‐job congruence nor gender added significantly to predictions of job satisfaction at 2 career stages. Earlier occupational choice and current job added to predictions of midcareer (modal age 43 years) job satisfaction, especially for men. The predictability of job satisfaction is apparently influenced by the career stage when satisfaction is appraised.     

穿越当代"经典"--文化寻根文学热点作品局限评述

所谓文学穿越,它一方面穿越的是政治和文化,并通过政治和文化走向人类关怀,另一方面穿越的是既定的各种世界观,建立起作家自己的世界观。本文所做的,就是依据一个作家应该建立起的对世界的独到的哲学性理解,来看中国新时期文学“文化寻根文学”阶段几部轰动性作品所存在的思想性和文学性局限。     

Neighborhood Structure,Social Organization,and Number of Short‐Term Sexual Partnerships

We examine the relationship between neighborhood structural characteristics, social organization, and the sexual partnering practices of adults. Analyses of 1990 census and 1995–1997 survey‐based data on Chicago neighborhoods and adult sexual activity reveal for men a number of neighborhood influences on sexual partnering practices. First, residential stability is negatively associated with having a short‐term sexual partner in the last year. Second, neighborhood social ties are positively associated with short‐term sexual partnering in neighborhoods with low levels of collective efficacy—the combination of cohesion and shared expectations for beneficial action among neighbors—but this effect is substantially reduced as collective efficacy increases. Moreover, neighborhood collective efficacy and social ties mediate the effect of residential stability on sexual partnering practices. Neighborhood characteristics were not associated with short‐term sexual partnering for women.     

African Americans and municipal employment: A test of two perspectives

A survey of the extant literature addressing the factors that drive African American municipal employment offers two broad types of explanations: (1) Black political power and (2) institutional. A comparative assessment of the performance of each of these explanations fills a gap in the literature by illuminating the differences of these distinct perspectives when it comes to employment of Blacks in the public sector. Focusing on six Florida cities from 1960 to 2000, this study tests the predictive power of each of these explanations comparatively for four city departments. The findings indicate that the Black political power explanation performs better than the institutional explanation as a predictor of Black employment.     

'The Tribunal was the most stressful thing: more stressful than my son's diagnosis or behaviour': the experiences of families who go to the Special Educational Needs and Disability Tribunal (SENDisT)

It is more than 10 years since the Special Educational Needs Tribunal was established in 1994 as an independent panel which arbitrates in disputes between parents of children with the label special educational needs and Local Education Authorities (LEAs) in England. In 2002 the Tribunal began hearing claims for disability discrimination and was re-named the Special Educational Needs and Disability Tribunal (SENDisT). Since 1994 over 20,000 appeals have been registered. This article, which forms part of my ongoing Ph.D. thesis 'Parents as advocates: the experience of parents who register an appeal with SENDisT', offers an analysis of parents' Tribunal stories. Here, the key question is what affect the process of going to SENDisT has on the social, emotional and financial well-being of the family. Through a process of narrative inquiry the aim is to foreground parents' unheard stories and to reveal their 'hidden' experiences.     

国内企业境外上市的动机及市场选择策略研究

文章分析了国内企业境外上市的现状、理论动机和现实动机,综合比较了境外主要资本市场特点,指出国内企业境外上市的资本市场选择因素主要包括境外交易所的定位、上市门槛及费用、市场规模和市场流动性.     

Detecting parameter shift in garch models

This paper applies recent theories of testing for parameter constancy to the conditional variance in a GARCH model. The supremum Lagrange multiplier test for conditional Gaussian GARCH models and its robustified variants are discussed. The asymptotic null distribution of the test statistics are derived from the weak convergence of the scores, and the critical values from the hitting probability of squared Bessel process.

Monte Carlo studies on the finite sample size and power performance of the supremum LM tests are conducted. Applications of these tests to S&P 500 indicate that the hypothesis of stable conditional variance parameters can be rejected.