A multi-purpose heuristic for communications satellite synthesis

Three satellite system synthesis problems—the satellite location problem, the signal protection problem, and the arc allotment problem—are described and formulated. In each of these problems, satellite administrations are to be allotted some portion of the geostationary orbit for the purpose of deploying their satellites, subject to angle of elevation and electromagnetic interference constraints. A simple heuristic procedure is suggested as a means for solving these three problems. Sufficient conditions for the successful application of the heuristic and solution-value bounds for each problem are presented. The heuristic is applied to each problem for a six-satellite example. Additionally, computational results are presented for an example with 183 satellites worldwide.     

Subdifferentiability and lipschitz continuity in experimental design problems

The calculus of concave functions is a widely accepted tool for optimum experimental design problems. However, as a function of the support points and the weights the design problem fails to be concave. In this paper we make use of generalized gradients in the sense of Rockafellar (1980) and Clarke (1983). A chain rule is presented for the subdifferential of the composition of an information function with the moment matrix mapping. Lipschitz continuity of the global design function is proved and conditions for strict differentiability are given.     

博弈论在工程项目冲突管理中的应用

在工程项目建设过程中,由于不同参与者的利益不一致,必然会引发冲突.选择利益关系密切的建设单位和施工单位可能出现的冲突为研究对象,用博弈论模型模拟工程项目的实施过程,对工程款支付过程中可能出现的冲突进行分析,提出解决冲突的思路和方法.     

Contact points and flash points: Conceptualizing the use of justice mechanisms in the performance appraisal interview

There has been a great deal of performance evaluation research, but little has been directed toward understanding subordinate responses to this process and developing ways to manage these responses. In contrast, the justice literature has identified mechanisms that directly influence recipient responses to organizational decisions. The present paper attempts to integrate justice theory and research into the performance appraisal interview. A conceptual model is presented that examines the relationship between three key justice mechanisms in the performance appraisal interview. Propositions are presented regarding the influence of these mechanisms using contact points (episodes where justice mechanisms are expected) and flash points (combinations of justice mechanisms that might lead to problems) as a basis for understanding how justice works in this context. Research is recommended to test these propositions. Implications for conducting performance appraisal interviews are discussed.     

Simple methods for uncapacitated facility location/allocation problems

Facility location/allocation problems are encountered in many different areas of management science. The methods presented in the literature are complex and are not easily understood by practitioners who are not trained in the techniques of optimization. Simple heuristic methods are presented in this article. The methods are developed for three different types of uncapacitated problems: (1) unlimited facility capacity with no fixed cost; (2) unlimited facility capacity with a fixed cost for assignment; (3) multiperiod problems. Examples are included to illustrate the basic methods.     

基于智能车竞赛推动民办院校电类专业改革及科技创新

智能车竞赛影响力广泛深远,随着民办院校对于该项赛事的参与,也暴露了民办院校在电类教学和学生科技创新能力培养等方面的问题,结合实际竞赛与教学经验,给出了基于智能车竞赛推动民办院校电类专业教学改革及科技创新的具体方案,旨在培养符合院情、国情的应用型人才。     

空余房地产租赁管理存在问题及对策探讨

本文简述了空余房地产租赁管理历史背景,查找了目前管理中存在的问题,以促进空余房地产租赁正规化管理,提出了推行集中统管、加强盘活利用、强化租赁管理、积极适应市场等对策,最后分析了瓶颈问题和发展前景。     

Parametric continuity in dynamic programming problems

We examine conditions under which the solutions to parametric families of dynamic programming problems are continuous in the parameters. Our main results are that parametric continuity obtains whenever either (a) the family of dynamic programming problems satisfies strong (joint-) continuity properties in the parameter and state or (b) if it satisfies weaker (separate-) continuity requirements, provided these are supplemented by either stronger assumptions on the transition probabilities or by monotonicity restrictions such as are common in economic modelling. The usefulness of our results is illustrated by applying them to some commonly used dynamic economic models.     

物流配送车辆调度问题算法综述

配送车辆调度优化问题旨在解决配送中路径和车辆调度问题的一类组合优化问题,是近年来物流控制优化领域的研究热点。文章对运输调度问题进行了分类总结,给出总体模型的概括描述,分析遗传算法、模拟退火算法、禁忌搜索算法、蚁群算法和微粒群算法的特点及其在求解配送车辆调度优化问题中的求解思路,并讨论了其求解现状,对未来研究方向进行展望,指出改进混合现有算法,开拓新算法将是更有效解决配送车辆调度问题的好方法。     

Testing the constancy in varying-coefficient regression models

Two hypothesis testing problems are considered in this paper to check the constancy of the coefficients in the varying-coefficient regression model. Tests for the two corresponding hypothesis testing problems are derived by two p-values. The proposed p-values can be thought as the generalized p-values, which are given by linear interpolation based on fiducial method. When all of the coefficients are constants, the p-value is uniformly distributed on interval (0, 1). Furthermore, the bound of the difference between the cumulative distribution function of the p-value and the uniform distribution on (0, 1) is given, which tends to 0 under some conditions. Meanwhile, the proposed tests are proved to be consistent under mild conditions. In addition, the proposed new method could be extended to include a broader range of hypotheses. Some good finite sample performances of the tests are investigated by simulations, in which a comparison with other test is given. Finally, a simple example based on real data is given to illustrate the application of our test, different result was obtained based on the proposed test.     

Implicit markets and the demand for housing characteristics

Important methodological problems in applying Rosen's (1974) model of implicit markets to housing characteristics are inadequately addressed in the literature. This paper summarizes these methodological issues and discusses advantages and disadvantages of various means of coping with these problems in empirical applications. Structural housing characteristics demand estimates are presented, along with an assessment of their accuracy. The results generally are insensitive to specification choices, suggesting the findings are plausible.     

Industrial districts and innovation: the case of the Spanish ceramic tiles industry

This paper examines the case of the Spanish ceramic tiles industrial district, with special emphasis on collective knowledge creation and innovation processes. Following a brief review of the literature based on industrial district characteristics, a framework with which to guide the empirical research is presented. The framework includes a set of conditions under which knowledge flows across firms' boundaries and how institutions shape knowledge diffusion. These include: (1) firm attributes; (2) the role of local institutions; (3) the importance of the social context; (4) lack of legal protection for innovations; (5) knowledge transmission mechanisms; and (6) specific outcomes of the district. These conditions are illustrated by using a comparative study, of which the key findings are as follows. First, the Spanish ceramic tile industrial district is characterized by small-sized firms, specialization and important product and technological overlaps. Second, there is the important role played by institutions, including academic and research institutions, as well as the relevancy of the social context and the lack of patents and other legal rights. There is also an intensive use of knowledge transmission mechanisms, such as the creation of firms, human resource mobility and informal channels of communication and, finally, a specific district technology and common perception of markets.     

Signed social structure optimization for shift assignment in the nurse scheduling problem

This paper develops a mathematical framework that relies on modern social network analysis theories for treating the nurse team formation and nurse scheduling (shift assignment) problems, accounting for signed social connections. These problems lie in assigning nurses to teams/shifts such that the constraints regarding both the working regulations and nurses preferences are satisfied. Recent research indicates the dependence of nursing team performance on team social structure; however, so far, the social structure considerations have not been explicitly incorporated into the mathematical formulations of the nurse scheduling problem. The presented framework introduces models that quantitatively exploit such dependence. This paper explores instances of Nurse Team Formation Problem (NTFP) and Nurse Scheduling Problem (NSP) incorporating signed social structure with the measures based on such network structures as edges, full dyads, triplets, k-stars, balanced and unbalanced triangles, etc., in directed, signed networks. The paper presents the integer programming formulations for NTFP and NSP, and a problem-specific heuristic that performs variable-depth neighborhood search to tackle NTFP instances with signed social structures. Computational results for a real-world problem instance with 20 nurses are reported. The insights obtained from the presented framework and future research directions are discussed.     

Properties of the CUE estimator and a modification with moments

In this paper, we analyze properties of the Continuous Updating Estimator (CUE) proposed by Hansen et al. (1996), which has been suggested as a solution to the finite sample bias problems of the two-step GMM estimator. We show that the estimator should be expected to perform poorly in finite samples under weak identification, in particular, the estimator is not guaranteed to have finite moments of any order. We propose the Regularized CUE (RCUE) as a solution to this problem. The RCUE solves a modification of the first-order conditions for the CUE estimator and is shown to be asymptotically equivalent to CUE under many weak moment asymptotics. Our theoretical findings are confirmed by extensive Monte Carlo studies.     

Generating search directions in multiobjective linear programming using the analytic hierarchy process

The algorithm presented in this paper describes an interactive approach for generating search directions in multiobjective linear programming problems (MOLP). The approach is based on using the AHP to assign priorities to vertices adjacent to those that are in the basis, as generated by the simplex method. Using these priorities, an approximate gradient is found that is used to weigh the objective functions during the next iteration. The novel feature of the algorithm is that the decision-maker (DM) is not required to provide interactive inputs to implicit preference questions concerning his objectives, but instead considers explicit evaluation of adjacent possible improvements to generate the next step in his most preferred direction.     

Argumatics: a text analysis procedure for supporting problem formulation

Problem formulation is the most critical phase of the decision making process. This, particularly in the case of high level multi-stakeholder problems, is not trivial, as the problems do not come “neatly packaged”. The procedure presented in this paper aims to support (i) the exploration of the stakeholders' mental constructs, and (ii) the generation, comparison and synthesis of alternative problem formulations. The suggested procedure — while using the decision analytic approach of the traditional text analysis procedures, follows an inverse, bottom-up direction of analysis: first the individual arguments inherent in the text are explored, then taking them as a starting point, the structures behind the arguments are identified.     

Identification of the dynamic shock-error model with autocorrelated errors

The paper gives (necessary and sufficient) conditions for the local identifiability of dynamic regression models with autocorrelated errors in the variables. The conditions are simple counting rules combining the order parameters of a model and directly generalize the results of Maravall and Aigner. A new method of identification is presented allowing a compact derivation of the results.     

生态学原理在城市规划中运用的思考

文章讨论了生态一词的涵义及其变化,归纳生态系统与城市的异同点,讨论了生态学原理与城市规划的结合,包括生态学原理及其在城市规划中的应用,当前存在的问题,今后的改进方向等,最后对长株潭规划生态环境专题研究案例进行了介绍。     

价值工程在后勤装备维修管理中的应用

信息化战争中,后勤保障力生成模式需要装备的RMS(Reliability,Maintainability and Supportability可靠性、维修性和保障性)来做支撑[1][2],而目前后勤装备的维修使用管理存在技术状况下降、经费不足、使用效率不高等问题,本文引入价值工程分析方法,针对后勤装备维修管理存在的问题,提出了后勤装备价值计算模型,并在实践中用价值工程分析方法对维修费用的使用提供决策参考。