Parameter estimation for partially observed hypoelliptic diffusions

Summary.  Hypoelliptic diffusion processes can be used to model a variety of phenomena in applications ranging from molecular dynamics to audio signal analysis. We study parameter estimation for such processes in situations where we observe some components of the solution at discrete times. Since exact likelihoods for the transition densities are typically not known, approximations are used that are expected to work well in the limit of small intersample times Δ t and large total observation times N  Δ t . Hypoellipticity together with partial observation leads to ill conditioning requiring a judicious combination of approximate likelihoods for the various parameters to be estimated. We combine these in a deterministic scan Gibbs sampler alternating between missing data in the unobserved solution components, and parameters. Numerical experiments illustrate asymptotic consistency of the method when applied to simulated data. The paper concludes with an application of the Gibbs sampler to molecular dynamics data.     

Social development needs assessment in China: lessons from an international collaborative field school in Guangxi Zhuang autonomous region

We explore the potential for rural and urban community needs assessment research in China, particularly in response to increasing rural to urban internal migration. Models for migration and community development are presented. We identify various methods that can inform social development planning, intervention, and evaluation. A collaborative community development field school in Guangxi Zhuang autonomous region was conducted with US and Chinese students and faculty. Plans for, and initial results of, a qualitative rural needs assessment are described. A semi‐structured urban resident needs assessment survey and the results of a small pilot study are presented. Challenges of international collaboration and implications and suggestions are reviewed.

本文探索了在中国农村和城市社区进行需求评估研究的潜力，特别是在回应不断增加的城乡人口流动。作者描述了各种移民和社会发展模式，并确定了几项可用于社会发展规划，干预和评估的方法。作者在广西壮族自治区建立了一所由美国和中国的学生和教员合作的社会发展田野考察学校，并描述了计划的内容和初步结果。作者在文中描述了一个评估城市居民需求的半组织性调查和一个小型试验研究的结果，并探讨国际合作所面对的挑战，影响和建议。     

‘Teaching should be observed’: a critical consideration of the issues involved in including teaching observation in the inspection of social work education

Social work education in England will have a new regulator from 2019. According to official sources, this is ‘as part of wider reforms to improve confidence in social work and raise the status of the profession’. In the background of any changes to social work education are the reports by Croisdale-Appleby (2014) and Narey (2014). Both reported that the existing regulatory regime was inadequate and made a combined total of 40 recommendations for improvement. Specifically, on the subject of social work teaching in higher education institutions, Narey expressed concern about both the content and quality and recommended that the teaching should be observed. If the incoming regulator were to introduce direct observations of teaching in inspections it would represent a new development. Previous regulators have not adopted this method. This discussion paper reviews selected literature on what teaching observation can and cannot achieve as an inspection method. It reflects on how social work education might gain if inspectors observed teaching. However, it also argues that to be a meaningful and credible process teaching observations need to take heed of a range of interrelated issues which, if not thought through properly, will invalidate the whole exercise.     

基于DSP2812的光伏MPPT控制系统

光伏电池的输出特性存在一个随外界环境变化而变化的最大功率点。为了能够最大限度地利用光伏转化出来的电能,必须进行最大功率点跟踪。采用DSP2812芯片用于最大功率点跟踪的主控制器并选择Boost拓扑作为主电路结构,介绍了采样电路和驱动电路等硬件电路的设计、软件与控制策略的设计。最终用实验验证了该控制系统能够快速稳定地跟踪光伏电池的最大功率点。     

有组织犯罪中的胁迫研究——对一个“黑帮”成长历程的入圈考察

当前,我国刑法理论对作为有组织犯罪常用手段的胁迫行为缺乏专门性的研究.对一个“黑帮”成长历程的入圈考察表明,暴力非但不是有组织犯罪的必要手段,(严重)暴力反倒是其法律风险的最大来源之一;贿赂“保护伞”亦不为黑帮生存发展所必需;一直被刑法忽略的一般胁迫行为已在现实社会互动中演化为黑帮生存发展的最优手段之一.与从前那种以“有组织暴力”为基石的黑社会组织一样,以“有组织胁迫”为主要犯罪手段的“黑帮”同样会侵害法益、破坏生活秩序,同时胁迫手段的使用大大降低了“黑帮”遭受刑事追诉的可能性,刑事立法亟待对此作出回应.     

青海贵德汉族节庆民俗变迁研究——以三河地区春节民俗为例

在中国现代化和全球一体化的背景下，青海各民族原有的生活方式、思想观念、民俗活动等传统文化正在产生或大或小的变化。本文以青海省贵德县三河地区为例，探究多民族聚集区汉族社会的节庆民俗变迁，在分析、诠释基础上，寻找文化变迁模式的地方性特征。     

“观察/实验负载理论”论题批判

新实验主义和科学实践哲学对“观察/实验负载理论”命题的批判观点和策略是:反对强化理论的观点;说明存在无理论负载的实验和观察;观察的所有报告不必然负载一个科学理论;某些实验更不必诉诸高层次理论,反而可能激励理论产生。这并不构成向实证主义的回归,而正在构成新的实践优位的科学实践哲学研究进路;给出对观察/实验与理论各种复杂关系的一个初步分析,观察/实验的确与理论的关系在不同阶段、有不同的特征和变化,不同品格的观察/实验与理论有不同的关系;不能以一个普遍的命题勾勒它们之间的关系。     

康德生态思想的现代观照

康德的《宇宙发展史概论》蕴涵着丰富而深刻的生态思想,其中关于宇宙起源、天体与天体系统、人类在自然界中的地位等学说,揭示了宇宙的物质统一性以及人与自然的对立统一关系,渗透着唯物论、无神论和辩证法。深入研究康德的生态思想,对当代中国构建和谐社会,启发人类解决生态危机的思路,具有重要的意义。     

网络分析视察法的扩充及应用

本文运用系统分析方法，对视察法进行扩充，提出了一种对任何复杂网络都适用的简便分析方法。     

论知识的确证与观察语句的关系

如何保证知识为真,历来是认识论研究的重点,逻辑经验主义者试图通过对观察语句的证实来完成知识的确证的任务。但是,在他们对于观察语句的上行路线与下行路线的分析上是存在严重问题的,因此,他们关于知识的确证的任务并没有成功实现。