Optimal and heuristic policies for dynamic server allocation

We examine a system where the servers in a cluster may be switched dynamically and preemptively from one kind of work to another. The demand consists of M job types joining separate queues, with different arrival and service characteristics, and also different relative importance represented by appropriate holding costs. The switching of a server from queue i to queue j incurs a cost which may be monetary or may involve a period of unavailability. The optimal switching policy is obtained numerically by solving a dynamic programming equation. Two simple heuristic policies—one static and one dynamic—are evaluated by simulation and are compared to the optimal policy. The dynamic heuristic is shown to perform well over a range of parameters, including changes in demand.     

Unintended consequences of emerging communication technologies: Instant Messaging in the workplace

With increased global connectivity, managers are faced with new technologies and rapid organizational changes. For instance, organizations may adopt emerging technologies such as Instant Messaging in order to increase collaboration at a distance and to decrease communications costs. However, the impact and implications of these technologies for managers and employees often go far beyond the original intent of the technology designers. Consequently, in this study, instant messaging (IM) and its use in organizations were investigated through interviews with employees. Results suggest that critical mass represents an important factor for IM success in the workplace that IM symbolizes informality, and that IM is perceived to be much less rich than face-to-face communication. Further, results demonstrate that employees use IM not only as a replacement for other communication media but as an additional method for reaching others. With IM, employees engage in polychronic communication, view IM as privacy enhancing, and see its interruptive nature as unfair. The paper concludes by discussing research and practice implications for organizational psychologists.     

Expert decision support system use,disuse, and misuse: a study using the theory of planned behavior

Researchers in the past decade have been actively investigating technology use and disuse among conventional and communications technologies. However, recent advancements in expert systems technology has led to new questions about technology use. Where communications technology, such as e-mail or group collaboration software, facilitates co-evolution of problem solving and decision making among people, expert systems create a transaction between user and computer where ultimately, the computer generates the recommended courses of action. This also differs from conventional decision support tools that merely gather information to inform a human decision maker.This empirical study used theory of planned behavior to formulate hypotheses about the use, disuse, and misuse of an expert system decision support (EDSS) technology. It was found that EDSS use was negatively related to errors, whereas misuse of EDSS was positively related to errors. More positive attitudes and social influences led to increased EDSS use, while perceptions of control had no apparent effect. The interaction of social influences and attitudes had a significant non-linear relationship with EDSS misuse.     

A Fast Scalable Classifier Tightly Integrated with RDBMS

In this pager,we report our success in building efficient scalable classifiers by exploring the capabilities of modern relational database management systems (RDBMS).In addition to high classification accuracy,the unique features of the approach include its high training speed ,linear scalability,and simplicity in implementation.More importantly,the major computation required in the approach can be implemented using standard functions provided by the modern realtional DBMS.Besides,with the effective rule pruning strategy,the algorithm proposed in this paper can produce a compact set of classification rules,The results of experiments conducted for performance evaluation an analysis are presented.     

Market penetration rates of new energy technologies

The market penetration rates of 11 different new energy technologies were studied covering energy production and end-use technologies. The penetration rates were determined by fitting observed market data to an epidemical diffusion model. The analyses show that the exponential penetration rates of new energy technologies may vary from 4 up to over 40%/yr. The corresponding take-over times from a 1% to 50% share of the estimated market potential may vary from less than 10 to 70 years. The lower rate is often associated with larger energy impacts. Short take-over times less than 25 years seem to be mainly associated with end-use technologies. Public policies and subsides have an important effect on the penetration. Some technologies penetrate fast without major support explained by technology maturity and competitive prices, e.g. compact fluorescent lamps show a 24.2%/yr growth rate globally. The penetration rates determined exhibit some uncertainty as penetration has not always proceeded close to saturation. The study indicates a decreasing penetration rate with increasing time or market share. If the market history is short, a temporally decreasing functional form for the penetration rate coefficient could be used to anticipate the probable behavior.     

A knowledge-based approach for task allocation in heterogeneous distributed computer systems

Abstract: This paper presents a knowledge-based system for task allocation in a network of processors. Since the problem is NP-complete, optimisation techniques are computationally prohibitive and impractical. Our approach reduces computational burden by using (1) a two-level hierarchical scheduling model to alleviate the problem complexity, and (2) a search strategy that uses knowledge from the knowledge base to limit the search space to a manageable size. The major goal of our approach is to generate good but not necessarily optimal solutions quickly. The system is implemented on a Sun SPARCstation 1 + using Common Lisp. Our computational experience in using this system for task allocation indicates that the two-level hierarchical approach generates better schedules in shorter computational time than a non-hierarchical approach.     

Strategic technology planning in hospital management

Abstract. Hospital managers regularly are confronted with their patients' demand for increased service performance on the one hand and tight budgets on the other. As medical technologies influence both the costs and the service spectrum, strategic technology planning is among the critical tasks in hospital management. This paper addresses the corresponding problem of selecting the “best” portfolio of medical devices and proposes an appropriate decision support system. It starts with a multiobjective mathematical programming model that determines the solution space of all efficient portfolios of medical technology investments. The members of the planning committee with their diverging interests then are supported by their interactive exploration of that space until they jointly reach a satisfying portfolio and are not willing to make any further compromises between its objective levels. As one of its salient features the system does not require a priori preference information. RID="*" ID="*" A previous version of this paper has been presented at the Wiesbaden 2000 Meeting of the GOR-Working Group “Operations Research in Health Care”. The authors thank Andrea Lührs and Thomas Rollins, both from Siemens AG, for their valuable support. Moreover, thanks are due to the anonymous referees for their comments on a previous version of this paper. Correspondence to: C. Stummer     

IS Strategic Planning for Operational Efficiency

The purpose of this article is to argue that, despite the constant economic upheaval and incessant technological changes, strategic planning for information systems is still a useful and critically important exercise for all organizations. Eight tenets for successful IS planning are identified from prior literature and then “tested” with two case studies in which operational efficiency is the strategic IS goal. One of the unexpected findings is that a high-level written plan is not a requirement if the IS objectives clearly target a specific operational objective of the business. The paper also introduces the notion of exploitation and exploration strategies—the former is best when operational efficiency is sought and the latter is needed when competitive advantage is the primary goal.     

基于层次分析法的科研项目评估系统实现

信息化的评估方式是提高科研项目评估效率和质量的重要手段。本文首先构建了基于层次分析法的科研项目绩效评估体系和模型;然后基于.Net框架,对项目绩效评估系统的流程和功能进行了设计;最后给出了该系统主要功能模块的实现过程。     

高职计算机类实训教学的研究

针对实践教学中实训的重要性,本文对高职教学中实验、实训、实习的概念及作用进行了比较,总结了计算机类实训教学存在的基地建设及管理方面的问题,并从国家、学校及学生三方面提出了解决对策。