186,525 research outputs found

    Taxonomic classification of planning decisions in health care: a review of the state of the art in OR/MS

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    We provide a structured overview of the typical decisions to be made in resource capacity planning and control in health care, and a review of relevant OR/MS articles for each planning decision. The contribution of this paper is twofold. First, to position the planning decisions, a taxonomy is presented. This taxonomy provides health care managers and OR/MS researchers with a method to identify, break down and classify planning and control decisions. Second, following the taxonomy, for six health care services, we provide an exhaustive specification of planning and control decisions in resource capacity planning and control. For each planning and control decision, we structurally review the key OR/MS articles and the OR/MS methods and techniques that are applied in the literature to support decision making

    Improving safety in Greek road tunnels

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    Tunnels are regarded as one of the most important infrastructures in Europe, as they may improve the connection of regions and aid economic development through facilitating the transportation of people and goods. In order to achieve a minimum acceptable level of safety, the EC issued Directive 2004/54/EC, which describes specific safety measures that have to be taken for all road tunnels in the trans-European road network. In parallel, there are several qualitative or quantitative methods for measuring road tunnel safety, while the method that seems to be the most accepted by administrative authorities for quantitative risk analysis is the OECD/PIARC QRA Model (QRAM), which has been developed by INERIS, WS-Atkins and the Institute for Risk Research. QRAM is based on engineering software that aids quantitatively assessment of the societal risk due to transporting goods and dangerous goods with Heavy Goods Vehicles (HGV) through road tunnels. The aim of this paper is to expose the effectiveness of the measures imposed by the EC in Greek road tunnels. A typical road tunnel, as designed and implemented after Directive 2004/54/EC, is compared to the same tunnel as if it was developed before the Directive was put into action. The comparison is made on the basis of the societal risk existing in the two cases. The conclusion of the paper, based on the outcome of the risk analysis with the QRAM method, is that the safety of Greek Tunnels is significantly improved due to the implementation of the measures imposed by the EC Directive 2004/54/EC

    A simplified activity-based costing approach for SMEs : the case study of an Italian small road company

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    Purpose: The paper proposes an original conceptual model for designing a simplified Activity-Based Costing (ABC) approach for Small and Medium-sized Enterprises (SMEs) by focusing on the transport sector. Design/Methodology/Approach: The model is designed starting from the distinctive characteristics of the SMEsā€™ collaborative culture. The approach is then tested in the case of an Italian small-road company. Findings: The simplified ABC, which was gradually introduced in the SME, allowed the firm to gain confidence with the costing system. Moreover, the discussion of the results led to identifying the main areas to improve. Practical Implications: Costing systems based on collaboration can lead to operational improvements in SMEs operating in dynamic and competitive sectors as transport. Moreover, advanced technologies may hold a crucial role for their development. Originality/Value: Not much research has considered collaboration as a driver for introducing ABC in SMEs. The paper contributes to the literature on simplified managerial approaches, suggesting trends for future research.peer-reviewe

    Technical and economic feasibility of gradual concentric chambers reactor for sewage treatment in developing countries

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    A major challenge in developing countries concerning domestic wastewaters is to decrease their treatment costs. In the present study, a new cost-effective reactor called gradual concentric chambers (GCC) was designed and evaluated at lab-scale. The effluent quality of the GCC reactor was compared with that of an upflow anaerobic sludge bed (UASB) reactor. Both reactors showed organic matter removal efficiencies of 90%; however, the elimination of nitrogen was higher in the GCC reactor. The amount of biogas recovered in the GCC and the UASB systems was 50% and 75% of the theoretical amount expected, respectively, and both reactors showed a slightly higher methane production when the feed was supplemented with an additive based on vitamins and minerals. Overall, the economical analysis, the simplicity of design and the performance results revealed that the GCC technology can be of particular interest for sewage treatment in developing countries

    Algorithm Engineering in Robust Optimization

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    Robust optimization is a young and emerging field of research having received a considerable increase of interest over the last decade. In this paper, we argue that the the algorithm engineering methodology fits very well to the field of robust optimization and yields a rewarding new perspective on both the current state of research and open research directions. To this end we go through the algorithm engineering cycle of design and analysis of concepts, development and implementation of algorithms, and theoretical and experimental evaluation. We show that many ideas of algorithm engineering have already been applied in publications on robust optimization. Most work on robust optimization is devoted to analysis of the concepts and the development of algorithms, some papers deal with the evaluation of a particular concept in case studies, and work on comparison of concepts just starts. What is still a drawback in many papers on robustness is the missing link to include the results of the experiments again in the design

    An overview of recent research results and future research avenues using simulation studies in project management

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    This paper gives an overview of three simulation studies in dynamic project scheduling integrating baseline scheduling with risk analysis and project control. This integration is known in the literature as dynamic scheduling. An integrated project control method is presented using a project control simulation approach that combines the three topics into a single decision support system. The method makes use of Monte Carlo simulations and connects schedule risk analysis (SRA) with earned value management (EVM). A corrective action mechanism is added to the simulation model to measure the efficiency of two alternative project control methods. At the end of the paper, a summary of recent and state-of-the-art results is given, and directions for future research based on a new research study are presented
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