EFFECTS OF INTERNET USE AND SOCIAL RESOURCES ON CHANGES IN DEPRESSION

We examine how people's different uses of the Internet predict their later scores on a standard measure of depression, and how their existing social resources moderate these effects. In a longitudinal US survey conducted in 2001 and 2002, almost all respondents reported using the Internet for information, and entertainment and escape; these uses of the Internet had no impact on changes in respondents' level of depression. Almost all respondents also used the Internet for communicating with friends and family, and they showed lower depression scores six months later. Only about 20 percent of this sample reported using the Internet to meet new people and talk in online groups. Doing so changed their depression scores depending on their initial levels of social support. Those having high or medium levels of social support showed higher depression scores; those with low levels of social support did not experience these increases in depression. Our results suggest that individual differences in social resources and people's choices of how they use the Internet may account for the different outcomes reported in the literature.     

建筑与城市设计中的时间观

时间与形式、功能、空间四要素完备才能组成一个完整的建筑 ,运用时间设计的概念 ,分析和解决当今建筑界和城市规划出现的问题是现实的需要     

积极进行教学资源建设全面推进教学改革

结合国家教学基地建设,西南交通大学以力学课程体系、教学内容、教学方法、教学手段的改革为主线,以培养工科创新型人才和提高教学质量为目标,构建了先进的立体化教学资源和教学平台,在课程教学与实验教学的改革、师资队伍建设、教学环境建设等方面取得了一系列成果,在全国,特别是西南地区,起到了很好的示范与辐射作用     

烟台市水资源承载力变化的驱动力研究

阐述了水资源承载力的概念、特性及影响因素,根据烟台市各县区的统计资料,分析了烟台市自上个世纪80年代以来水资源承载力变化的总体趋势和驱动因子。结果表明:人口、社会固定资产投资和GDP是影响烟台市水资源承载力变化的主要驱动因素。通过多元线性回归模型,预测出了2005和2015年的水资源量,并进一步预测了该市的需水量和缺水量。     

马克思主义与时俱进的哲学思考

马克思主义具有与时俱进的理论品质。马克思主义哲学是这个理论品质的理论基础。实践与理论的矛盾运动、对真理的探求、以及创造崭新的马克思主义话语体系,都要求马克思主义与时俱进。     

Economic Determinants of Net International Migration in Western Europe

This paper aims to estimate theinfluence of economic determinants on netinternational migration in Western Europe inthe period 1960–1998. Net migration rates(i.e., population growth minus natural increase,divided by the midyear population) constitutethe dependent variable. The economicdeterminants used in this study are GDP percapita, unemployment, and average educationallevel (amount of human capital) of thepopulation. Time series regression models havebeen used in country-specific analyses. Inaddition, a pooled cross-sectional time seriesanalysis has been made. The analyses suggestthat GDP per capita has a positive effect andunemployment a negative effect on a country'snet international migration.     

西部自然资源评价：准则与政策建议

从西部开发旨在“兴地富民”的角度出发 ,基于产权准则和市场需求准则 ,西部自然资源可作如下系统分析和评价 :土地、水和清洁能源是西部地方性资源但不具有现实优势 ;在现行资源产权制度下 ,石油、天然气和稀土矿产资源是国家级资源 ,煤炭是准地方性资源 ,一般矿产为西部地方性资源。矿产资源能否成为西部地方性优势资源不仅取决于矿产资源的类型 ,还取决于矿产资源的市场需求以及矿产资源产权制度的创新。     

高校合并后的资源共享问题探析

对高等院校合并后各校区（学院）之间图书馆在新的环境和新的需求下如何构建文献资源共享信息网络，加强当代大学生信息素质教育，提高图书馆员的信息服务水平三个方面进行了初步论述。     

Conditional Likelihood Estimators for Hidden Markov Models and Stochastic Volatility Models

ABSTRACT.  This paper develops a new contrast process for parametric inference of general hidden Markov models, when the hidden chain has a non-compact state space. This contrast is based on the conditional likelihood approach, often used for ARCH-type models. We prove the strong consistency of the conditional likelihood estimators under appropriate conditions. The method is applied to the Kalman filter (for which this contrast and the exact likelihood lead to asymptotically equivalent estimators) and to the discretely observed stochastic volatility models.