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JE Samouilidis 《Omega》1980,8(6):609-621
The Arab oil embargo in 1973 and the subsequent price rises and production restrictions have given birth to a distinct branch within Management Science: energy modelling. This paper gives a critical and selective review on energy modelling, an industry which though thriving in an era of general economic anxiety, is showing signs of arrogant immaturity. After giving a historical background, the paper classifies energy models into three groups: open loop demand or supply models; energy closed loop models; energy-economy closed loop models. For each group the problem area is analysed and some illustrative examples are described. In the last sections, an attempt is made to sum up the experience that has been gained with energy modelling: the basic deficiencies, the impact of this activity on policy formulation and its position within Management Science. It is concluded that energy models, though very poor forecasting devices, can be very useful to policy makers as tools for analysis; energy model developers must convince potential model users and for that purpose they can benefit immensely from the 35-year-long experience accumulated by their colleagues in Management Science. 相似文献
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The paper discusses the problem of design and analysis of large scale communication systems. An iterative process, composed of a minimum cost network design algorithm and a network performance algorithm, is presented for the solution of these problems. Computational considerations, using these algorithms, are discussed. 相似文献
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In this paper some of the techniques available for strategic planning are reviewed. Four techniques are presented, the experience curve, the growth-share matrix, the directional policy matrix and the PIMS program. The results of a survey into the use of these techniques in the United Kingdom are also presented. 相似文献
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《史记》是中国史学中一部继往开来的不朽巨著,作者司马迁开创的以人物为中心的纪传体,在汉代以后一直是历代王朝正史所沿用的体制。司马迁修《史记》,不仅尊重历史事实,秉笔直书,而且还注意语言文字的锤炼,文句优美。他将叙事、抒情、说理的不同文体有机地综合起来,达到思想上、艺术上的高度统一,为后代文史创作提供了范例。《史记》不仅是中国纪传体史书的开创者,而且对后世的散文、小说、戏曲都产生了深远的影响。同时它也早已流传至国外,在汉文化圈国家中亦有不小的影响。其中,《史记》传入韩国,特别受到韩国知识界人士的关心和推崇,为韩国学术界所重视。到了1960年代中期,随着国家经济的发展,韩国整个社会的发展进入了一个历史的新时期,不仅国家面貌发生了根本性变化,学术文化事业也步入正轨,同时韩国学术界对中国学术文化的关心及研究也重新得到了高度重视。正是在这样的基础上,韩国学者对《史记》的翻译和研究有了较大的进展,在传播、普及和通俗化方面作出了积极的贡献。本文除简述《史记》在韩国的流传背景外,还分别论述自1971年至2010年近四十年来《史记》在当代韩国的翻译介绍与研究现状,并对其研究成果上存在的一些不足和空缺作一番客观的评价。 相似文献
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Energy constitutes a small fraction of the production inputs in the economy, yet the rigidity imposed by the short and medium term inability to substitute energy with other production factors in case of an energy shortage, requires the establishment of safeguard mechanisms to ensure sufficient energy supply during an emergency. These safeguards usually take the form of strategic energy reserves. A methodological approach is presented here, relating the level of strategic petroleum reserves, the decision variable, with the costs associated with their storage and the economic losses incurred by an energy shortage. This approach is based on the use of a decision tree, to portray emergency scenarios. Each scenario, a branch of the decision tree, can be evaluated in terms of a cost function which includes the inventory procurement and maintenance cost and the shortage cost inflicted by a petroleum shortfall. 相似文献
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JE Beasley 《Omega》1983,11(4):403-408
In this paper we consider route first—cluster second methods for the vehicle routing problem. Extensions to the basic method both to improve its effectiveness and to enable it to cope with practical constraints are described. Computational results are given for the method applied to standard vehicle routing problems drawn from the literature. 相似文献
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In this paper we consider the problem of vehicle routing using fixed delivery areas. This is the problem of splitting the area serviced by a depot into a number of separate subareas—a single delivery vehicle being assigned to each subarea to supply all the customers within the subarea. A heuristic algorithm is developed for the problem based upon an initial allocation of customers to subareas followed by customer interchanges in an attempt to improve the subareas. Computational results are presented for a number of test problems drawn from the literature. 相似文献
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JL Sligo HM McAnally JE Tansley JM Baxter AE Bolton KM Skillander 《Kōtuitui : New Zealand Journal of Social Sciences Online》2017,12(1):41-55
The living arrangements of young people in New Zealand are diverse and often complex. In this article we report the range of care and living arrangements of 209 15-year-old New Zealanders, 47 of whom identified as Māori. These young people were participants in the second generation of a cohort study. Data were collected from their parents via a life history calendar and analysed for variety and consistency of care arrangements, household membership and transitions. Few participants had a consistent pattern of parental care arrangements and most had experienced multiple changes in household composition and frequent changes of address. We conclude that the whānau/family lives of many young New Zealanders are complex and dynamic. These observations contrast with the conventional notions of family life that form the basis for New Zealand’s family policies. We argue that social policies and services impacting on young people need to reflect the lived reality of young people if they are to meet young people’s needs. 相似文献