Penalty guided genetic search for redundancy optimization in multi-state series-parallel power system

This paper presents a genetic algorithm (GA) for parallel redundancy optimization in series-parallel power systems exhibiting multi-state behavior, optimizing the reliability subject to constraints. The components are binary and chosen from a list of products available in the market, and are being characterized by their feeding capacity, reliability, cost and weight. System reliability is defined as the ability to satisfy consumer demand and is presented as a piecewise cumulative load curve. In GA, to handle infeasible solutions penalty strategies are used. Penalty technique keep a certain amount of infeasible solutions in each generation so as to enforce genetic search towards an optimal solution from sides of, both, feasible and infeasible regions. We here present a dynamic adaptive penalty function which helps the algorithm to search efficiently for optimal/near optimal solution. To evaluate system reliability, a fast procedure, based on universal generating function, is used. An example considering a multi-state series-parallel power system is solved considering both homogeneous and heterogeneous types of redundancy. Also an example considering price discounts is solved. The effectiveness of the penalty function and the proposed algorithm is studied and shown graphically.     

Correlation in a Bayesian framework

The authors consider the correlation between two arbitrary functions of the data and a parameter when the parameter is regarded as a random variable with given prior distribution. They show how to compute such a correlation and use closed form expressions to assess the dependence between parameters and various classical or robust estimators thereof, as well as between p‐values and posterior probabilities of the null hypothesis in the one‐sided testing problem. Other applications involve the Dirichlet process and stationary Gaussian processes. Using this approach, the authors also derive a general nonparametric upper bound on Bayes risks.     

The reflective diary: an experiential tool for enhancing social work students’ research learning

There has been substantial discussion internationally about the need for social work students to integrate research into practice. Little has been written, however, about teaching methods that address the cognitive and emotional challenges students experience in their efforts to develop research competencies. Many students believe that research does not apply to the ‘real’ world of practice and are anxious and fearful when they begin a research course. Using a retrospective review of students’ assignments, this article describes the use of reflective diaries in teaching MSW students from a university in the USA skills for practice-based social work research. Reflective diaries provide a safe forum for students to actively engage with the challenges they experience while taking a research course and take ownership of their learning needs. The diary entries provide instructors with windows into their students’ learning processes that enable them to create scaffolding opportunities that support students in developing confidence in their research skills. This article describes the pedagogical philosophy behind reflective diaries, details of the diaries assignment, and benefits of this learning tool for students and instructors. The authors offer recommendations for incorporating reflective diaries into social work research courses and implications for evidence-based practice.     

Action Learning in the Indian Village as an Alternative to the Traditional Field Practicum in the Foundation Year of the MSW

This paper captures the experiences of the faculty members of a relatively new graduate social work program situated in the largely rural state of Haryana India in reframing the foundation year practicum through community-based and engaged action learning in small villages. Located within Bhagat Phool Singh Vishwavidyalaya (BPSMV), north India's first all women public university, the mission of which is to enhance women's engagement in the greater society through post-secondary, professional and character education, the department is educating social workers for community engagement in social development and in the development of women as an empowered group in society, particularly at the village level. Over a three-year period, the faculty has successfully launched and sustained action learning as an alternative to the traditional practicum in social work education, enhanced civic engagement among students and faculty in three rural villages, and further developed community social work as a principal focus of social work education in India. The paper offers a rationale for action learning in the graduate social work curriculum, describes and documents the department's strategy of action learning, and lays out lessons learned from action learning as a central focus of pedagogy, research, and service within BPSMV Department of Social Work and the rural villages it serves.     

社会工作研究的人文精神——对以实证主义为导向的美国社会工作研究的批判

长期以来,国际社会工作研究常常倾向于以实证主义和经验主义为基础的研究导向,特别是在美国,基于证据的研究方法在社会工作领域十分流行。随着全球化的推进和人们生活方式的现代化,社会工作研究所面临的问题更为复杂,其解决方法单纯依靠各种技术处理的手段来展开是远远不够的,我们在讨论这些问题时,要强化其价值导向。这要求我们在讨论社会工作研究的问题上,把我们的关注点从证据、技术手段和职业标准扩展到价值观、人文精神和对全球化问题的关注等方面,以此来推进国际社会工作的发展。     

Bayesian robustness for multiparameter problems

Bayesian robustness is studied for ε-contamination classes of prior distributions. Nonparametric classes of contsminations such as the class of all unimodal spherically symmetric densities are considered here. Posterior φ-divergence and its curvature are used to measure the sensitivity of priors on the resulting posterior densities. Examples are provided to illustrate our results.     

Reporting cumulative proportion of subjects with an adverse event based on data from multiple studies

Experience has shown us that when data are pooled from multiple studies to create an integrated summary, an analysis based on naïvely‐pooled data is vulnerable to the mischief of Simpson's Paradox. Using the proportions of patients with a target adverse event (AE) as an example, we demonstrate the Paradox's effect on both the comparison and the estimation of the proportions. While meta analytic approaches have been recommended and increasingly used for comparing safety data between treatments, reporting proportions of subjects experiencing a target AE based on data from multiple studies has received little attention. In this paper, we suggest two possible approaches to report these cumulative proportions. In addition, we urge that regulatory guidelines on reporting such proportions be established so that risks can be communicated in a scientifically defensible and balanced manner. Copyright © 2010 John Wiley & Sons, Ltd.     

On the equivalence of two approaches to simplicity in the analysis of block designs and some related results

Two seemingly different approaches to simplicity in the analysis of connected block designs, and their relationship to the concepts of balance are discussed.