A class of symmetric bivariate uniform distributions

A class of symmetric bivariate uniform distributions is proposed for use in statistical modeling. The distributions may be constructed to be absolutely continuous with correlations as close to±1 as desired. Expressions for the correlations, regressions and copulas are found. An extension to three dimensions is proposed.     

Open Road or Blind Alley? Welfare Reform, Mothers, and Children with Disabilities

Welfare reform was examined for 39 Michigan families whose children have significant health or intellectual and behavioral disabilities. As a group, these families received little specialized assistance or services to address their unique needs. Family-cited barriers to self-sufficiency included poorly trained welfare caseworkers, limited public transportation, and inadequate child care. Having an older child was the only discriminating variable between working and non-working mothers. However, working mothers only had temporary positions with no benefits and low pay. All families, whether employed or not, lived below the poverty line.     

谈新教师的角色投入

新教师要树立正确的角色意识 ,培养深厚的角色情感 ,锻炼角色耐受挫折的能力 ,养成角色的文明行为习惯 ,加强角色的反思和更新 ,以促进角色的成熟和发展     

青史凭谁定是非——评宋齐丘的历史功过

宋齐丘一生历经磨难和坎坷，曾四为宰相，贵为三公，助徐知诰“兴利除害，变更旧法”，并提出和推行了具有远见卓识的税制改革，戮力劝农，对吴、唐社会经济的发展作出了巨大的贡献，推动了历史的前进。他从此居功自傲，挟旧邀功，贪权固位．并长期卷入朝中朋党之争，最终葬送了自己。宋齐丘一生有功有过，但功大于过，是值得充分肯定的，应给其以公正的历史评价。     

论观点采择与皮亚杰的去自我中心化

关于儿童对个人的心理过程、心理特征的认知的研究始于皮亚杰。皮亚杰提出了“自我中心化”和“去自我中心化”的概念 ,在社会认知发展的研究中占有重要的地位。观点采择的本质特征在于个体认识上的去自我中心化 ,即能够站在他人的角度 ,从他人的角度看待问题。对观点采择的研究是对皮亚杰关于儿童自我中心化和去自我中心化发展研究的继承和发展     

少年儿童不同时期的生理特征及其拳击运动的身体训练

论述了少年儿童拳击运动身体训练的可行性及重要性，分析了少年儿童不同时期的生理特征及与之相适应的拳击运动身体训练方法手段的选择，可为少年儿童拳击运动的科学化训练提供理论依据。     

王安忆小说中的童年意象

童年意象的运用是王安忆小说独树一帜的重要原因."成长中的儿童"是王安忆小说中特有的形象.以儿童形象为象征载体进行文化批判是对童年意象的出色运用.儿童视角的发掘使王安忆的小说取得了"陌生化"的审美效果,也使细节化呈现文本的艺术表达方式与文本的精神内涵完美地结合起来.儿童视角的运用还让作家能以旁观者的眼光看世界,保持了独立、警醒的创作立场.     

论壮族服饰变迁的缘由

服饰是人类文化的重要组成部分，是一个民族的重要标志之一。民族服饰不是一成不变的，每一个民族在其发展过程中，都有一个相对独立的服饰变迁史，壮族服饰同样经历了一个发展演变的历程。在壮族服饰习俗的发展和演化过程中，自然环境、物质条件、社会文化环境和心理环境等对其产生重大影响。     

剑溪堂刻本《书经》考述

剑溪堂刻本《书经》为近年在徽州地区发现的一种《尚书》新版本。根据其书口、版式、字体、用纸、内封面以及避讳等情况综合判断,该书刊行于明神宗万历年间,与北图藏元明间宗文书堂刻本《书集传音释六卷》同出一个版本系统。它的出现对于认识《书经》乃至整个《尚书》的流变史有其重要意义。在蔡沈集传《书经》普遍流行六册、七册线装本的情况下,三册毛装本无疑还具有较强的版本认识价值。     

Statistical Distributions of Daily Breathing Rates for Narrow Age Groups of Infants and Children

Children may be more susceptible to toxicity from some environmental chemicals than adults. This susceptibility may occur during narrow age periods (windows), which can last from days to years depending on the toxicant. Breathing rates specific to narrow age periods are useful to assess inhalation dose during suspected windows of susceptibility. Because existing breathing rates used in risk assessment are typically for broad age ranges or are based on data not representative of the population, we derived daily breathing rates for narrow age ranges of children designed to be more representative of the current U.S. children's population. These rates were derived using the metabolic conversion method of Layton (1993) and energy intake data adjusted to represent the U.S. population from a relatively recent dietary survey (CSFII 1994–1996, 1998). We calculated conversion factors more specific to children than those previously used. Both nonnormalized (L/day) and normalized (L/kg-day) breathing rates were derived and found comparable to rates derived using energy estimates that are accurate for the individuals sampled but not representative of the population. Estimates of breathing rate variability within a population can be used with stochastic techniques to characterize the range of risk in the population from inhalation exposures. For each age and age-gender group, we present the mean, standard error of the mean, percentiles (50th, 90th, and 95th), geometric mean, standard deviation, 95th percentile, and best-fit parametric models of the breathing rate distributions. The standard errors characterize uncertainty in the parameter estimate, while the percentiles describe the combined interindividual and intra-individual variability of the sampled population. These breathing rates can be used for risk assessment of subchronic and chronic inhalation exposures of narrow age groups of children.