时间贝叶斯网络及其概率推理

针对贝叶斯网络应用中出现的循环和动态问题,研究贝叶斯网络的时间扩展.给出了时间贝叶斯网络的定义;探讨了时间贝叶斯网络中环的存在合理性判断问题;给出了时间贝叶斯网络的概率推理算法,应用示例说明了方法的可行性.     

Begging as work: a study of people with mobility difficulties in Accra, Ghana

Even though begging is illegal in Ghana, an increasing number of disabled people engage in it. Begging is not only abhorred by the law, but also regarded by many Ghanaians as stigmatizing and devaluing. Successive governments of the country and some non-governmental organizations (NGOs) have made efforts either to reduce or eliminate begging. The attempts made have, however, been unsuccessful and the disabled beggars involved have returned to the streets of Accra. The question is why is it difficult to reduce begging in the research area. While poverty, mobility needs, lack of education and employable skills and employment avenues are factors that explain the decision to start begging, it also seems that the ways in which beggars justify their activities contribute to its perseverance. The study aims at sensitizing policy-makers and other stakeholders in attempts to find empowering alternatives to begging.     

西北地区已就业农村大学生的工作状况及困境分析——基于甘肃省农村大学生的个案分析

在大学生就业形势日益严峻的当下,分析已就业农村大学生这一特殊群体的生存状况,对农村大学生个体和农村社会文化、教育、经济的发展以及和谐社会的建构都有十分积极的意义。通过深度访谈已就业农村大学生的生存状况发现：国家政策的大力扶持对农村大学生实现代际阶层的社会流动具有决定作用;已就业农村大学生在工作中,应以积极的心态和自强不息的奋斗努力实现＂知识真正改变命运＂。     

“于是”与事理承接

以往对承接复句的分析说明主要是从时间关系或顺序入手的。以新的视角从逻辑意义入手 ,可将承接复句分为时间承接与事理承接两类。综合考察“于是”连接的“事理承接”复句的语义、语法与语用 ,可发现 :前后逻辑语义的密切相关、动态性、完成性与描写性是这类承接复句的主要特征。     

Getting Out and About: The Relationship Between Urban Form and Senior Travel Patterns

As the overall U.S. population expands outward from the central city and core suburbs and as people age in place, more seniors will reside in suburban and exurban locations. This research seeks to determine whether older adults who live in areas with differing urban forms experience travel pattern variations under controls for other factors related to travel. We analyzed data from a telephone survey of a random sample of seniors aged 75 years and older and we employed a unique approach for establishing the urban form of their residential settings. The results show that urban form does influence travel patterns, including the number of trips and transportation mode, and suggest that the construction of compact, mixed-use communities where today's older adults can age in place may be part of the solution to addressing the mobility needs of our aging population.     

基于自动机模型数据关联性能评估算法

提出了一种基于自动机理论的性能评估方法,通过在有限自动机模型中增加描述观测的时间序列,来扩展其对数据关联过程的表达能力;使用时序有限自动机模型来描述关联处理算法的模型;使用带时间属性的字符串表示目标航迹。对数据关联的时序有限自动机模型进行一致性和可达性分析,并在此基础上给出了性能评估算法。实验结果证明该方法可以有效地评价关联算法的性能。     

科举对清代社会流动的影响——基于清代朱卷作者之家世分析

通过对《清代朱卷集成》七千多名举子家世的分析,可以看出,在清代,尽管获得科举功名者大多数出身于较高社会阶层,出身于上五代均无功名家庭的举子要实现向上流动相当艰难,但一定比例的布衣借着科举得以升迁的事实,说明他们仍有一个较为公平的上升渠道。姻亲和母系家族对于举子提升社会阶层几无助力。居住城市的举子实现向上流动的机会要比乡居举子大得多,但家世在实现社会流动的过程中起着远比居住地更为重要的作用。     

减租减息与淮北抗日根据地农民的社会流动

抗日战争时期,党在淮北抗日根据地实行了比较彻底的减租减息,它在经济上削弱了封建剥削,改善了农民的社会生活,促进了根据地土地和阶级关系的变化,引发了根据地农民的社会流动和阶级结构的变化,有利于根据地社会的稳定,为根据地的巩固与扩大奠定了坚实的基础.     

Testing lack of symmetry in spatial–temporal processes

Symmetry and separability of a covariance function are common assumptions to simplify the modeling effort of spatial–temporal processes. However, many studies in environmental sciences show that real data have complex spatial–temporal dependency structures resulting from lack of symmetry or violation of other standard assumptions of the covariance function. In this study, we propose new formal tests for lack of symmetry by using spectral representations of the spatial–temporal covariance functions of regularly spaced spatial–temporal data. The advantage of the proposed tests is that classical analysis of variance (ANOVA) models can be used for detecting lack of symmetry inherent in spatial–temporal processes. We evaluate the performance of the tests with simulation studies and we apply them to air pollution data.