带工期指派的产品服务系统订单随机调度问题研究

针对由一个制造工厂和多个区域服务中心组成的服务型制造企业,研究了考虑生产时间和服务时间均具有随机性且工期可指派的产品服务系统（PSS）订单调度问题。首先以最小化订单提前、误工和工期指派费用的期望总额为目标构建问题的优化模型,然后分析目标函数近似值的最优性条件,据此提出加权最短平均生产时间排序规则,并结合该规则与插入邻域局部搜索设计了启发式算法对问题进行求解,最后通过数值仿真验证算法的可行性和有效性。研究表明,提前费用偏差对PSS订单调度与工期指派决策的影响很小,因此企业管理者无需准确估计库存费用也能制定出比较有效的PSS订单调度策略;而工期指派费用偏差对决策结果的影响非常大,因此企业管理者在决策时必须谨慎估计该项费用。     

Due Date Assignment,Job Order Release,and Sequencing Interaction in Job Shop Scheduling*

Depending on the techniques employed, the due date assignment, release, and sequencing procedures in job shop scheduling may depend on one another. This research investigates the effects of these interactions with a simulation model of a dynamic five-machine job shop in which early shipments are prohibited. Performance of the system is measured primarily in terms of the total cost (work-in-process cost, finished goods holding cost, and late penalty) incurred by the shop, but a number of non-cost performance measures are also reported. The results support existence of a three-way interaction between the due date, release, and sequencing procedures as well as interaction between shop utilization and procedure combination. Statistical tests are used to identify those rules that perform best both overall and in combination with other rules.     

Labour Mobility in Europe as a Result of Changes in Central and Eastern Europe*

Abstract. International migration of labour has become a burning issue and is on the lips of politicians, social scientists, employers and workers. It has has become a global issue, with national borders becoming less important due to process of economic integration. The issue is very complicated since many factors are involved: unemployment, the stand of trade unions and national movements often opposing more liberal immigration rules, non-adherence of countries to international norms, in particular ILO labour standards. However, there are also gains for both labour-exporting and labour-importing countries. The article tries to trace the history of international norms concerning international migration of labour, as well as to touch upon hard facts accompanying such migration. It is difficult to collect these in a systematic manner, given the dearth of information on the subject, due to its sensitivity. However, the paper provides a variety of contro-versial information which is from the press rather than from official data, and therefore difficult to verify. It is a subject on which considerable prejudice clouds rational debate.     

Limitations to Freedom: is there a Choice for Human Resource Management?

There is a great variety in human resource management (HRM) practices, not only in terms of policies and personnel activities, but also with regard to the parties involved and the procedures for decision-making. But which factors can best account for these differences? Are they due to organizational and environmental characteristics or are they basically due to the interests, preferences and power positions of the parties concerned - parties like management, employees, personnel management staff, trade union representatives, members of the works council and so on? Based on elements of industrial relations theory, organization theory and organization sociology, a research project was set up with the aim of gaining a better understanding of the factors which can shape HRM practices. The empirical part of the research consisted of paired comparative case studies from different industries. The result is a conceptual model which not only encompasses the relevant forces in the shaping of HRM, but also states the conditions determining the amount of room for manoeuvre the parties concerned have to make their own strategic choices with regard to HRM.     

决策单元交叉效率的自适应群评价方法

传统交叉效率评价方法因决策单元偏好权重不唯一而难以操作,因交叉效率有效性分值平均化集结而难以被接受。目前的学者通常围绕决策单元指标权重的确定性分配方法、交叉效率有效性分值的去平均化集结等分别开展研究。本文将交叉效率评价方法中自评互评相结合的评价模式看作群决策过程,即每个决策单元既是一个被评对象,又是一个决策"专家",提出了一种决策单元交叉效率的自适应群评价方法,将决策单元偏好权重的确定和交叉效率有效性分值的去平均化集结作为同一个决策过程,根据每个决策单元的评价结果与群体评价结果的接近程度,同步迭代调整决策单元的"专家"权重和决策单元自评产生的、并提供给其他被评价决策单元的一组确定的偏好指标权重。实验验证与实例运用分析表明,该方法收敛效果良好,能得到客观稳定的决策单元交叉效率有效性分值及排序。     

Calibrated Incentive Contracts

This paper studies a dynamic agency problem which includes limited liability, moral hazard, and adverse selection. The paper develops a robust approach to dynamic contracting based on calibrating the incentive properties of simple benchmark contracts that are attractive but infeasible, due to limited liability constraints. The resulting dynamic contracts are detail‐free and satisfy robust performance bounds independently of the underlying process for returns, which need not be i.i.d. or even ergodic.     

The Impact on Inequality of Raising the Minimum Wage: Gap‐narrowing and Reranking Effects

Raising the minimum wage may reduce inequality by increasing the wages of low‐skill workers, but it may also increase inequality due to negative impacts on employment that produce wage losses. Using previous estimates of the elasticities of wages and employment to changes in the minimum wage in Colombia and Brazil, we show that the net impact on inequality of increasing the minimum wage may depend on the distributional weights used for inequality measurement. The results are obtained by decomposing the Gini index into reranking and gap‐narrowing effects. Inequality‐increasing reranking effects, which are associated with job losses, may dominate inequality‐decreasing gap‐narrowing effects, which are associated with wage gains, when high weights are placed on workers with low earnings. For standard distributional weights, however, the likely net impact is a reduction in wage inequality.     

国际金融危机对我国GDP影响到底多大?

本文利用区分加工出口的非竞争型投入产出模型,从受到金融危机影响最为直接的出口、投资角度出发,测算了国际金融危机对我国GDP到底产生了多大的影响。测算结果显示:金融危机对我国经济的负面影响是逐步加剧的;重点行业影响较为集中;由于我国宏观调控政策的及时准确,刺激经济计划的有效实施在很大程度上抵消了金融危机的影响。     

Coaching in globalen Unternehmen: Beispiele aus Europa, den USA und China

This article first identifies what a select group of globally operating companies has been implementing in the way of coaching over the last years. In particular, different coaching approaches in Europe, USA, and China are reviewed in the context of these organizational examples. The particular practices are evaluated in light of possible theoretical underpinnings due to the continuing scarcity of sound empirical research on coaching. Addressing the need for first-hand examples of deployed coaching programs, the following offers practitioners the opportunity to extract information on the types of coaching interventions which have been successfully implemented and what criteria are important to consider when rolling out a coaching intervention in a global business environment. Recommendations and lessons learned on selecting coaches are also provided.     

Productivity Competitiveness among Non Cooperating Integrated Economies: A Negative-Sum Game

ABSTRACT: The strategies adopted by European countries during the 1970‘s and 1980‘s have been unsuccessful in their attempt to produce more employment. These strategies have been centred on attempts to improve the international position of a country at the expense of the others through increasing productivity and competitiveness. The negative effects on employment due to higher productivity should have been offset, in the longer run, by an increasing share of exports. But the eventual result has been that relative positions of countries have remained fundamentally unchanged. This is due to the fact that all countries adopted the same strategy. Aggressive strategies do not pay in terms of employment. More effective policies, in a situation characterized by accelerated technical progress, can be more easily implemented in a more co-operative international context. Even if there is no moral solidarity between the nearly related races of Europe, there is an economic solidarity which we cannot disregard. Even now the world markets are one. This is to put the issue on its lowest grounds. There are other arguments, which the most obtuse cannot ignore, against a policy of spreading and encouraging further the economic ruin of great countries (J.M. Keynes) ¹⁸     

STRATEGIES FOR SOLVING ECONOMIC PROBLEMS INVOLVING PERMUTATIONS

A number of common economic problems can be reduced to a search for a permutation which minimizes some function. Analytic solutions are available for unconstrained problems of this nature when certain conditions are satisfied. This article outlines a simple tree-search strategy for solving ordering problems in which some permutations are excluded due to explicit constraints.     

供需中的Hockey-stick现象分析及对策研究

许多公司的产品需求在连续而固定的周期会出现前低后高,即 Hockey-stick 现象,这种现象普遍存在于供应链之中并困扰着许多的企业管理者.不认为其产生的原因是公司对销售人员的周期性考评的传统观点,并以快速消费品行业为背景,通过建立模型,得出了这种现象主要是公司普遍采用的总量折扣(Volume Discounts)价格政策导致的结论,并提出了公司可以通过多产品组合定价等方法缓和这个问题,最后通过一个实例证实了文章的观点.     

Sequencing heuristics for dependent setups in a continuous process industry

In this paper we address the scheduling of Biaxially Oriented Polypropylene (BOPP) film production, which belongs to the plastics industry and is a continuous process. Scheduling problems in BOPP film production involve processing different thickness settings of films on a common facility. Customer orders of the same thickness setting are usually grouped together as a production batch and a setup time is incurred whenever the batch is switched. However, there is usually more than one batch for the same thickness setting because of the due date constraints of the orders. Therefore, there is a need to develop a batching and sequencing scheme that minimizes the total setup time, or equivalently the makespan, under the due date constraint. In this paper heuristics are developed to generate a near-optimal solution for the problem. The heuristics are evaluated by an optimal solution procedure and are tested by using the actual data from a plant making the BOPP film. Comparison of the heuristics with the results of the current system has demonstrated a significant reduction in total setup time.     

A dynamic ERP critical failure factors modelling with FCM throughout project lifecycle phases

Implementation of enterprise resource planning systems (ERPs) is a complex and costly task which usually results in serious failures. Numerous factors affect these projects implementation due to their size, complexity and high chance of failure. Therefore, identifying these factors in ERP projects is a critical issue. The majority of previous publications have been conducted in identifying ERP critical success factors (CSFs) rather than critical failure factors (CFFs). In order to help practitioners, this article studies the CFFs in ERP implementation projects. The implications of interdependency among failure factors are also usually overlooked by project managers due to perceived complexity in modelling and analysing influential factors. With this in mind, we have proposed a fuzzy cognitive map (FCM)-based dynamic model of ERP failure factors through project lifecycle phases. The main advantage of FCM lies in them being capable of modelling complex phenomena based on the experts’ perceptions. This tool models uncertainty and related events, imitating human reasoning. Moreover, FCMs enable the developing of forecasting exercises through simulations. Practitioners would thus assess the joint influence of ERP implementation failure factors on project outcomes. The results make known to practitioners which problems will arise if the failure factors are not treated, and how these will impact on the outcomes of projects. Therefore, the proposed approach would help them to manage ERP implementation projects in a more effective and proactive way.     

Medical capacity investment for epidemic disease: The effects of policymaker's confidence and public trust

Due to the server bed shortage, which has raised ethical dilemmas in the earliest days of the COVID-19 crisis, medical capacity investment has become a vital decision-making issue in the attempt to contain the epidemic. Furthermore, economic strength has failed to explain the significant performance difference across countries in combatting COVID-19. Unlike common diseases, epidemic diseases add substantial unpredictability, complexity, and uncertainty to decision-making. Knowledge miscalibration on epidemiological uncertainties by policymaker's over- and underconfidence can seriously impact policymaking. Ineffective risk communication may lead to conflicting and incoherent information transmission. As a result, public reactions and attitudes could be influenced by policymakers' confidence due to the level of public trust, which eventually affects the degree to which an epidemic spreads. To uncover the impacts of policymakers' confidence and public trust on the medical capacity investment, we establish epidemic diffusion models to characterize how transmission evolves with (and without) vaccination and frame the capacity investment problem as a newsvendor problem. Our results show that if the public fully trusts the public health experts, the policymaker's behavioral bias is always harmful, but its effect on cost increment is marginal. If a policymaker's behavior induces public reactions due to public trust, both the spread of the epidemic and the overall performance will be significantly affected, but such impacts are not always harmful. Decision bias may be beneficial when policymakers are pessimistic or highly overconfident. Having an opportunity to amend initially biased decisions can debias a particular topic but has a limited cost-saving effect.     

Measurement of changes: What criteria do we adopt?

Many changes in industrial working methods are now under discussion which are not easily evaluated and management is concerned about the probable return from investing in these methods. It is proposed that, whilst it is clear that improving work performance is a benefit, it is also of benefit to achieve changes in attitudes which correlate more closely with the objectives and state of the enterprise. Increased agreement in this respect is stated to lead to increased stability for the production process as there is less likelihood of disruption of output due to inappropriate decisions and actions. Since the loss due to various forms of interruption in output can be assessed it is described how the benefit of attitude change might thus be measured. A model for the relationships relevant to ergonomic and behavioural science changes in industry is given and its potential is illustrated by examples.     

An improved algorithm for tree edit distance with applications for RNA secondary structure comparison

An ordered labeled tree is a tree in which the nodes are labeled and the left-to-right order among siblings is relevant. The edit distance between two ordered labeled trees is the minimum cost of transforming one tree into the other through a sequence of edit operations. We present techniques for speeding up the tree edit distance computation which are applicable to a family of algorithms based on closely related recursion strategies. These techniques aim to reduce repetitious steps in the original algorithms by exploring certain structural features in the tree. When these features exist in a large portion of the tree, the speedup due to our techniques would be significant. Viable examples for application include RNA secondary structure comparison and structured text comparison.     

网络销售中退货担保与定价决策

本文采用退货担保期权综合完全退货策略与部分退货策略的优点,构建了网络销售中基于期权的退货与定价模型,以商品的价格、退货策略和退货担保期权价格为决策变量,讨论了存在退货期权和不存在退货期权两种情况下,最优决策存在的条件,求解出销售商最优价格、退货策略和退货担保期权价格,分析了各个市场参数变化对最优值的影响,通过对担保退货期权与退货策略同时存在和购买期权才能退货二种策略的比较,发现供应商最优策略是前者。算例验证了以上结论,做了敏感性分析,总结了相关管理启示与未来研究方向。所得结论对网络销售商开展网上销售有重要参考价值。     

随机加权交叉效率下的资源分配问题研究

资源在经济发展中的地位变得越来越重要,本文针对资源分配中存在的某些影响因素是随机的,提出利用随机DEA方法,从三方面综合分析研究资源分配问题,即从生产效率、投入产出弹性和生产潜能。提出并建立了新的随机加权交叉效率计算模型,建立了潜在生产能力模型,给出了规模回报计算公式。综合三个影响因素,建立了新的资源分配权重计算模型。经算例验证,其计算结果令人满意。     

绩效考核对高校教师工作满意度的影响:职业压力的中介作用

在中国高校全面实施校内岗位津贴及配套政策的情境下,探讨绩效考核对教师工 作满意度的影响。大样本调查结果显示,绩效考核对工作满意度的影响有3条路径：绩效考核对工作满意度直接的积极影响;绩效考核通过职业压力的中介作用,间接影响工作满意度;绩效考核通过考核认知的中介作用,影响职业压力,进而影响工作满意度,其中第1条路径的影响最强,第2条路径的影响相对较弱。高校教师这一职业存在高职业满意度、低薪酬满意度并存的现象。