Multivariate distributions defined in terms of contours

The paper deals with the problem of using contours as the basis for defining probability distributions. First, the most general probability densities with given contours are obtained and the particular cases of circular and elliptical contours are dealt with. It is shown that the so-called elliptically contoured distributions do not include all possible cases. Next, the case of contours defined by polar coordinates is analyzed including its simulation and parameter estimation. Finally, the case of cumulative distribution functions with given contours is discussed. Several examples are used for illustrative purposes.     

A second order model for cylindrical data

Modeling cylindrical data, comprised of a linear component and a directional component, can be done using Fourier series expansions if we consider the conditional distribution of the linear component given the angular component. This paper presents the second order model which is a natural extension of the Mardia and Sutton (1978) first order model. This model can be parameterized either in polar or Cartesian coordinates, and allows for parameter estimation using standard multiple linear regression. Characteristic of the new model, how to compare the adequacy of the fit for first and second order models, and an example involving wind direction and temperature are presented.     

Discriminant coordinates analysis for multivariate functional data

Abstract

One of the basic statistical methods of dimensionality reduction is analysis of discriminant coordinates given by Fisher (1936 Fisher, R. A. 1936. The use of multiple measurements in taxonomic problem. Annals of Eugenics 7 (2):179–88. doi:10.1111/j.1469-1809.1936.tb02137.x.[Crossref] , [Google Scholar]) and Rao (1948). The space of discriminant coordinates is a space convenient for presenting multidimensional data originating from multiple groups and for the use of various classification methods (methods of discriminant analysis). In the present paper, we adapt the classical discriminant coordinates analysis to multivariate functional data. The theory has been applied to analysis of textural properties of apples of six varieties, measured over a period of 180?days, stored in two types of refrigeration chamber.     

Cognitive-Behavioral Therapy for Bipolar Disorder: Implications for Clinical Social Workers

ABSTRACT

The purposes of this review article are to orient clinical social workers to cognitive-behavioral theory, intervention, and research on bipolar disorder (BD); identify pros and cons of applying cognitive-behavioral therapy (CBT) to social work clients with BD; and identify specific implications for clinical social work practice. Of the 545 articles that were obtained via the systematic review, 18 studies were identified as being potentially eligible for inclusion, and 9 of those studies ultimately satisfied the inclusion criteria. The results of each study were summarized via identifying statistically significant (p< .05) differences that existed between experimental cohorts who received CBT (plus pharmacotherapy) and control cohorts who received treatment as usual. Outcomes showed CBT cohorts as having significant improvement over their respective control groups. The review's implications for clinical social workers and the need for future research are discussed.     

我国网络舆情研究的进展分析（2014—2018） ——基于战略坐标图

为揭示我国网络舆情研究领域的热点主题及其之间的关联,提出现存的问题及未来的趋势,抓取了2014—2018年CSSCI来源期刊刊载的网络舆情相关文章的关键词,构建高频词的共词矩阵,使用聚类分析将高频词聚集成7个类团,并采用战略坐标图揭示类团内部及类团之间的关系。研究发现,我国网络舆情研究主要集中在舆情传播的仿真建模,基于大数据的微博网络舆情传播模式,突发事件、公共热点事件和群体性事件的网络舆情演化等7个领域。我国网络舆情研究存在对舆情传播中个体特征的研究较少,对微信以及移动互联网环境中舆情的研究较少等问题。移动互联网环境中网络舆情的传播与演化、个体情绪认知对网络舆情传播的影响等是潜在的重要研究主题。     

Linearity,symmetry, and equidistance in semantic differential scales for measuring images of self and images of others

ABSTRACT

Violations of linearity, symmetry, and equidistance of scale points in semantic differential scales may be due to respondents failing to figure out antonyms, to a positivity bias, or to respondents curtailing their reading the options. Multiple correspondence analysis on data provided by a randomized between-subjects experiment (split-ballot), using a web survey of 537 German residents, shows that bipolar semantic differential scales allow for linear measurement and conceal no positivity bias, and that using not suitable adjective pairs in semantic differential scales destroys symmetry.     

均匀场中部分球的静电问题和应用

对于某些微波场的问题,本文利用在均匀静电场中导物体的微扰效应作为近似解,解决了在均匀场中不完全球形电极的这样一个问题.     

高速SOI-LIGBT的数值分析

研制出Ｈｅ离子注入局域寿命控制ＳＯＩ横向绝缘栅双极晶体管（ＳＯＩ－ＬＩＧＢＴ），有效地提高了器件的关断速度，且与集成电路工艺相兼容。数值模拟表明，该器件的t_f～V_F折衷关系优于采用非局域寿命控制的器件，在相同关断速度下其正向压降可降低０．６～１．４ Ｖ，避免了阳极短路结构的正向快速返回现象。     

普通台面工艺制作新型超薄基区负阻HBT

负阻型HBT既保持了原HBT高频、高速的特点,同时又具有负阻、双稳、自锁等特性,是一种极具研究价值的新型负阻器件。该文从Early效应造成超薄基区穿通,器件由双极工作状态向体势垒管工作状态转变从而形成负阻特性的思路出发,通过对材料结构的特殊设计,采用普通台面工艺研制出了基区厚度为8nm的负阻型HBT。该器件具有独特且显著的可变电压控制型负阻特性,其电流峰谷比大于1000,并伴有电流控制型负阻。