Who is a volunteer? A cultural and temporal exploration of volunteerism

This study’s purpose was to develop a temporal and cultural definition of volunteering in China. Using a comparative mixed-methods approach, N₁ = 218 Chinese students in Hong Kong were surveyed about their perceptions of volunteering. These quantitative data were compared cross-culturally with a sample of adults in the United States who used the same instrument called Who is a Volunteer? Subsequently, N₂ = 40 of these same students voluntarily participated in a series of focus groups, to further explore more in-depth their opinions about volunteering. The main quantitative results revealed that at the extreme ends of the volunteer scale, both the U.S. and Chinese samples could readily distinguish what volunteering was or was not. The more nuanced empirical differences on the scale (24% of the 21 items) were explained either by unique cultural differences, or the longer and more prominent history that volunteering has had in North America versus China. Main qualitative findings revealed additional between-group cultural differences exemplified by (1) a more family-centric and collectivist Chinese culture versus a more individualistic American culture, (2) a role blurring about volunteer activities versus paid work activities, and (3) that both organizational and cultural context must be seriously considered when defining volunteerism. This study adds to the growing definitional literature on this transformational concept and represents the largest comparative empirical investigation on this subject from East Asia.     

基于多源遥感的城市生态用地识别及生态风险评价

随着城市化进程的不断推进、建设用地不断扩张,城市生态空间正处于剧烈变化中。大量具有生态价值和服务功能的土地不断被侵占,以满足暂时的城市建设需求。但从长远来看,这些生态用地的"消失",将不可避免的影响区域生态平衡,给区域经济的健康发展埋下隐患。广州作为华南的中心城市,改革开放以来,大量外来人口涌入,土地利用变化频繁,生态环境的保护面临着巨大压力。因此,本文基于多源遥感数据,利用监督分类法与综合指数法相综合的复合提取方案对2016年广州生态用地进行空间识别,掌握广州市生态用地存量现状。同时,借助生态风险小区和生态风险等景观指数对广州进行了生态风险评估,结果显示,广州市生态风险呈现明显的多核圈层结构,由多核心的中心向外部逐渐降低。     

Statistical analysis of dependent competing risks model in accelerated life testing under progressively hybrid censoring using copula function

This article considers statistical analysis of dependent competing risks model from Weibull distribution in accelerated life testing, in which copula function is used to examine the dependence structure between competing failure modes. We derive the maximum likelihood estimates, the approximate, and Bootstrap confidence intervals of the parameters. The effects of different dependence structures on the estimates of parameters are investigated. The simulation is given to compare the performance of the estimates when the competing failure modes are dependent with those when the failure modes are independent. Finally, one dataset was used for illustrative purpose in conclusion.     

More on the restricted Liu estimator in the logistic regression model

?iray et al. proposed a restricted Liu estimator to overcome multicollinearity in the logistic regression model. They also used a Monte Carlo simulation to study the properties of the restricted Liu estimator. However, they did not present the theoretical result about the mean squared error properties of the restricted estimator compared to MLE, restricted maximum likelihood estimator (RMLE) and Liu estimator. In this article, we compare the restricted Liu estimator with MLE, RMLE and Liu estimator in the mean squared error sense and we also present a method to choose a biasing parameter. Finally, a real data example and a Monte Carlo simulation are conducted to illustrate the benefits of the restricted Liu estimator.     

Monitoring the coefficient of variation using a variable sample size and sampling interval control chart

This article proposes a CV chart by using the variable sample size and sampling interval (VSSI) feature to improve the performance of the basic CV chart, for detecting small and moderate shifts in the CV. The proposed VSSI CV chart is designed by allowing the sample size and the sampling interval to vary. The VSSI CV chart's statistical performance is measured by using the average time to signal (ATS) and expected average time to signal (EATS) criteria and is compared with that of existing CV charts. The Markov chain approach is employed in the design of the chart.     

Disequilibrium multi-dividing ontology learning algorithm

As an effective tool for data storage, processing, and computing, ontology has been used in many fields of computer science and information technology. By means of its powerful performance on semantic query and knowledge extraction, domain ontology has been built on various disciplines such as biology, pharmaceutics, geography, chemistry, etc. and been smoothly employed for their engineering applications. In these ontology applications, we aim to get an optimal ontology function which maps each ontology to a real number and then determine the similarity between concepts by the distance of their corresponding real numbers. In former ontology learning approaches, all the instances in the training sample have equal status in the learning process. In this article, we present the disequilibrium multi-dividing ontology algorithm in which the important ontology data will be highlighted during the learning, and the relevant ontology data tend to be eliminated. Four experiments are designed to test the serviceability of our disequilibrium multi-dividing algorithm from angles of ontology similarity measuring and ontology mapping construction.     

Penalised spline estimation for generalised partially linear single-index models

Generalised linear models are frequently used in modeling the relationship of the response variable from the general exponential family with a set of predictor variables, where a linear combination of predictors is linked to the mean of the response variable. We propose a penalised spline (P-spline) estimation for generalised partially linear single-index models, which extend the generalised linear models to include nonlinear effect for some predictors. The proposed models can allow flexible dependence on some predictors while overcome the “curse of dimensionality”. We investigate the P-spline profile likelihood estimation using the readily available R package mgcv, leading to straightforward computation. Simulation studies are considered under various link functions. In addition, we examine different choices of smoothing parameters. Simulation results and real data applications show effectiveness of the proposed approach. Finally, some large sample properties are established.     

论民族、民族国家与现代民族国家——以中国本土学术话语中的“民族”为中心

中国本土学术话语中的“民族”概念有一个演进的过程.古代“族”的概念以及“族类”观构成了中国传统文化中的一种群体分类体系.近代“民族”的使用始于西方术语翻译和汉语由文言向白话的转变,明显受到西方民族-国家和民族主义理论的影响.新中国成立后,马克思主义与苏联模式长期在我国民族理论研究中占据主导地位,围绕民族译名及民族形成问题出现过几次论争.20世纪90年代以来,国内学界对民族概念的讨论日益朝解构和多元反思的方向发展.综而观之,中国本土民族概念的传统导源于中华民族历史形成的多元一体格局,强大的包容性使其逐渐形成了内涵丰富、外延宽泛、使用灵活的独特话语体系.目前学界对民族国家与现代民族国家的使用不够规范,建议把民族国家作为特指性概念专门指称西欧早期民族国家,而把现代民族国家作为泛指性概念,用来指称所有时期和类型的民族国家.     

德勒兹的“块茎”与阿多诺的“星丛”概念之比较

块茎和星丛这一对概念,分别是德勒兹和阿多诺用来取代既定体系的理想模式。这两种模型互有异同,其中最关键的重合点在于它们都聚焦在新事物的产生过程。同时,这两种关系模型都打破了传统哲学中占据统治地位的同一性逻辑,转而提倡一种非等级化的关系。然而,在对关系的强调中,它们各自的重点却有所区别:块茎强调逃逸线,而星丛则更关注成员之间的共存于互相中介的关系。这种区别造成了这两种生产性的关系模式在异质性生产方面的巨大的区别。德勒兹的"块茎"模式在一定程度上是对批判理论的悲观性的超越。而理解这一区别,对于如何在今天的社会现实中将批判性与建构性相结合十分重要。