Security optimal power flow considering loading margin stability using hybrid FFA–PS assisted with brainstorming rules

This paper presents a new power system planning strategy which combines firefly algorithm (FFA) with pattern search algorithm (PS). The purpose is minimizing total fuel cost, total power loss and reducing total voltage deviation, with the objective of enhancing the loading margin stability and consequently the power system security. A new interactive and simple mechanism, inspired in brainstorming process, is proposed that allows FFA and PS algorithms to explore new regions of the search space. In this study the Static VAR compensator (SVC) is modeled and integrated in an efficient location which is chosen considering the voltage stability index. The proposed algorithm is interactive and tries to optimize a set of control variables at the same time, namely, active power generations, voltage of generators, tap transformers, and the reactive power of shunt compensators to optimize three objective functions such as: fuel cost, total power loss and total voltage deviation. These variables are optimized using a flexible interactive and competitive search mechanism. The proposed planning strategy has been examined and applied to two practical test systems IEEE 14-Bus and IEEE 30-Bus. Simulation results confirm the effectiveness of this hybrid strategy for solving the security optimal power flow.     

How do interactive tabletop systems influence collaboration?

This paper examines some aspects of the usefulness of interactive tabletop systems, if and how these impact collaboration. We chose creative problem solving such as brainstorming as an application framework to test several collaborative media: the use of pen-and-paper tools, the “around-the-table” form factor, the digital tabletop interface, the attractiveness of interaction styles. Eighty subjects in total (20 groups of four members) participated in the experiments. The evaluation criteria were task performance, collaboration patterns (especially equity of contributions), and users’ subjective experience. The “around-the-table” form factor, which is hypothesized to promote social comparison, increased performance and improved collaboration through an increase of equity. Moreover, the attractiveness of the tabletop device improved subjective experience and increased motivation to engage in the task. However, designing attractiveness seems a highly challenging issue, since overly attractive interfaces may distract users from the task.     

Dynamic tabletop interfaces for increasing creativity

We designed a tabletop brainwriting interface to examine the effects of time pressure and social pressure on the creative performance. After positioning this study with regard to creativity research and human activity in dynamic environments, we present our interface and experiment. Thirty-two participants collaborated (by groups of four) on the tabletop brainwriting task under four conditions of time pressure and two conditions of social pressure. The results show that time pressure increased the quantity of ideas produced and, to some extent, increased the originality of ideas. However, it also deteriorated user experience. Besides, social pressure increased quantity of ideas as well as motivation, but decreased collaboration. We discuss the implications for creativity research and Human–Computer Interaction. Anyhow, our results suggest that the Press factor, operationalized by Time- or Social-pressure, should be considered as a powerful lever to enhance the effectiveness of creative problem solving methods.     

Relationship analysis in requirements engineering

This research addresses a major shortcoming in todays requirements analysis techniques—the lack of a rigorous and comprehensive process to explicitly capture the relationship structure of the problem domain. Whereas other analysis techniques lightly address the relationship discovery process, relationship analysis (RA) is a systematic, domain-independent analysis technique focusing exclusively on a domains relationship structure. This paper describes RAs taxonomy of relationship types and corresponding brainstorming questions for eliciting the relationship structure from a domain expert. A preliminary case study analysis of online bookstores using RA as well as a formal experiment have both confirmed RAs effectiveness in helping the analyst produce significantly higher quality requirements. RA should become an invaluable tool for analysts, irrespective of the software engineering approach taken during systems analysis.     

食品科学专业教学中“头脑风暴法”的应用探讨

头脑风暴法是一种从心理上激励群体创新思维的通用方法,被德国教育界引入教学领域,成为行为引导型教学法中的一种方法,在教学中运用头脑风暴法有利于培养学生的创新思维,拓宽学生的知识面;有利于加强师生交流,调动学生的积极性;有利于培养学生的团队精神。将"头脑风暴法"应用到食品科学专业教学中,用于学生发散思维和创新能力的培养,效果显著。     

Understanding contexts by being there: case studies in bodystorming

A thorough appreciation of physical, social, interactional, and psychological contextual factors is crucial in the design of ubiquitous computing applications. This paper investigates the benefits of a method called bodystorming for carrying out design sessions in the original context, `in the wild', instead of the office. A location is selected that is identical or similar to the original environment. Innovation, carried out on-site, is based on ethnographical data presented as concrete design questions. Individual solutions to design questions are brainstormed and discussed on-site. Facets of data collection and preparation, formulation of design questions, selection of locations, session administration, and evaluation of design ideas are presented. We found that bodystorming permits immediate feedback for generated design ideas, and can provide a more accurate understanding of contextual factors. Bodystorming sessions were found memorable and inspiring. It is best suitable for designing for activities that are accessible and unfamiliar to the researchers.