Energy modelling: A new challenge for management science

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.     

Large scale communication networks—Design and analysis

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.     

The use of strategic planning techniques in the United Kingdom

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.     

近四十年来韩国《史记》研究综述（1971—2010）

《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。     

Productive engagement among older Americans: prevalence, patterns, and implications for public policy

This study estimates the prevalence of productive engagement among adults aged 60 and over residing in the United States over a nine-year period. We analyze three waves of data from the Americans' Changing Lives Study, which allows the findings to describe the non-institutionalized older American population. Focusing upon five activities--formal paid employment, irregular paid work, unpaid volunteerism, caregiving, and informal assistance to others--we identify changes in the engagement rates, examine the extent to which engagement occurs through single or multiple concurrent activities, and document intra-individual patterns of engagement within and across forms of productive activity, including the continuity, initiation, and cessation of involvement. The findings reveal that late-life productive engagement is widespread, with the majority of older individuals involved in multiple forms of activity concurrently. Non-market-based activities such as caregiving, informal assistance, and volunteering are most prevalent. Initiation and cessation of activities are common and yield more complex patterns and lower rates of non-participation than are revealed in cross-sectional analyses. Time spent in productive engagement is highly variable and exhibits an overall decline across time. We conclude by highlighting policy strategies to increase the availability and quality of opportunities for productive engagement and promote planning for engagement in late life.     

Externalizing Behavior Among Adopted Boys with Preadoptive Histories of Child Sexual Abuse

This study examined the severity of externalizing symptomology among adopted boys with preadoptive histories of child sexual abuse, physical abuse, neglect/abandonment, or no abuse. The study was based on data collected across a three-year period from parents who adopted children from Florida's child welfare system. The sample consisted of 1,136 adopted boys aged 6 to 18 years. In repeated cross-sectional multivariate analyses, the results revealed that adopted boys with preadoptive child sexual abuse were prone to significantly higher levels and clinically severe externalizing symptomotology as compared to adopted boys without such histories. The findings highlight the need for postadoption services and empirically validated interventions for families adopting boys with preadoptive child sexual abuse.     

A methodological approach to strategic petroleum reserves

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.     

Productive Engagement Among Older Americans: Prevalence,Patterns, and Implications for Public Policy

This study estimates the prevalence of productive engagement among adults aged 60 and over residing in the United States over a nine-year period. We analyze three waves of data from the Americans' Changing Lives Study, which allows the findings to describe the non-institutionalized older American population. Focusing upon five activities—formal paid employment, irregular paid work, unpaid volunteerism, caregiving, and informal assistance to others—we identify changes in the engagement rates, examine the extent to which engagement occurs through single or multiple concurrent activities, and document intra-individual patterns of engagement within and across forms of productive activity, including the continuity, initiation, and cessation of involvement. The findings reveal that late-life productive engagement is widespread, with the majority of older individuals involved in multiple forms of activity concurrently. Non–market-based activities such as caregiving, informal assistance, and volunteering are most prevalent. Initiation and cessation of activities are common and yield more complex patterns and lower rates of non-participation than are revealed in cross-sectional analyses. Time spent in productive engagement is highly variable and exhibits an overall decline across time. We conclude by highlighting policy strategies to increase the availability and quality of opportunities for productive engagement and promote planning for engagement in late life.     

Route first—Cluster second methods for vehicle routing

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.