物流配送中心选址研究

系统介绍了以降低成本与提高服务效率为目标的传统物流系统配送中心选址模型的发展与特点。在此基础上，介绍了近年来在供应链环境影响下发展而来的考虑库存成本与各级企业利益协调的现代配送中心选址模型。     

供应链分销系统成本最小化模型

研究由多个制造商、一个中间仓库和多个分销商组成的供应链分销系统,建立综合考虑库存成本、订货成本和运输成本的分销网络成本最小化模型,并在此基础上进行简单的实例分析。     

一种多周期易腐品库存路径问题模型及其求解算法

通过分析一个供应商用多个相同车辆向多个客户配送一种易腐品,在随机需求下,满足多个周期中客户的服务水平、决策计划期内的配送路线和配送量,以库存持有成本、货损成本、运输成本最小化为目标,建立随机需求的多周期易腐品库存路径问题模型,将库存控制和运输问题整合优化。还针对该模型设计了一种改进的遗传算法,能够保证初始种群以及变异、交叉后的种群的多样性和优越性,有足够搜索全局最优解的能力。     

多仓联储模式下的集成生产库存决策

为了探究多仓联储模式下集成化供应链生产与供给配送的最优决策,以供应链总运营成本最小化为目标,构建了多仓联储模式下的集成生产与库存分配模型,基于迭代局部搜索算法原理构建求解算法,用以解决实际大规模情形下的生产计划与库存分配决策问题。通过实验表明,集成生产与仓储分配决策方法能够有效协调生产以及多个仓库间的分配调度,为仓库节省大量的仓储空间,同时能够合理地进行资源的运输调度,从整体上降低了供应链的生产与仓储运输成本。     

基于客户满意度的配送中心选址研究

随着企业竞争的加剧以及电子商务的发展,物流经营理念随之发生了改变,企业对客户的满意度越来越受到重视,从原来的为客户服务向使客户满意的方向转变。所以,配送中心需要不断提高服务水平,使顾客达到最大的满意度。而传统的配送中心选址只是以简单的考虑运输成本、建设成本及总成本的最小为目标,因此,本文将顾客满意度引入到配送中心选址模型中,建立以物流成本最小化和顾客满意度最大化为目标的配送中心选址多目标模型,并提供了模型相应的求解方法。     

不确定性物流中心选址问题研究

结合物流中心选址过程中的不确定因素,从仓储和运输管理的角度出发,建立基于库存策略的物流中心选址问题随机期望值规划模型。模型以综合成本(包括库存成本、运输成本和建设成本)最小为优化目标函数,运用混合智能算法对选址问题的随机期望值模型进行求解,结合比较算例与既有文献的计算结果,得出建设成本在时间段影响下综合成本的结论。     

装车地直达情况下电煤库存优化模型研究

针对火电企业库存成本费用高、对库存与运输的联合研究较少等问题,主要从火电企业角度出发建立自身系统费用目标函数研究装车地直达情况下电煤库存问题。针对电厂库存连续变化的特点,引入0-1决策变量,获得更贴近实际的电厂库存量。以运输能力、库存限制、配煤比例作为模型约束条件,使得火电企业包括订购成本、运输成本、库存成本、燃煤费用以及装卸费用在内的自身总费用最小,并通过与实际相符的算例来验证模型的可行性与有效性。     

装车地直达情况下电煤库存优化模型研究

针对火电企业库存成本费用高、对库存与运输的联合研究较少等问题,主要从火电企业角度出发建立自身系统费用目标函数研究装车地直达情况下电煤库存问题.针对电厂库存连续变化的特点,引入0-1决策变量,获得更贴近实际的电厂库存量.以运输能力、库存限制、配煤比例作为模型约束条件,使得火电企业包括订购成本、运输成本、库存成本、燃煤费用以及装卸费用在内的自身总费用最小,并通过与实际相符的算例来验证模型的可行性与有效性.     

造船企业易耗品配送成本控制研究

为解决当前造船企业易耗品领用人工成本突出的问题,提出构建易耗品配送模式并进行配送成本控制研究。以配送成本最小化为目标,建立满足车间时间约束的车辆路径优化模型,运用遗传算法对模型求解,以国内某船厂为例进行计算和分析。结果表明该方法能够有效降低配送车辆运输成本、提高物料配送效率,相比传统领用模式成本更低,为造船企业转变传统方式、提升管理水平、实现准时化生产提供参考。     

基于快递运输的手机零件供应链改进研究

一些手机零件企业没有设置产品安全库存。他们完全按照客户订单从供应商处采购产品,并使用快递运输。然而供应链中的各种不确定因素造成了频繁的交货延误。作者对这种供应链进行了简单介绍,分析了其中存在的问题,建立了包含安全库存成本和快递运输成本的供应链成本模型．并且以手机扬声器为例计算了安全库存,为企业对快递公司的评价和安全库存的设置提供了参考工具。     

Data center supply chain configuration design: A two-stage decision approach

Data centers are special-purpose facilities that enable customers to perform cloud based real-time online transactions and rigorous computing operations. Service levels of data center facilities are characterized by response time between query and action, which to a large extent depends on data center location and data travel distance. Another aspect of service level is resource up-time availability, which is determined by data center configuration. Data center location and configuration decisions are, therefore, of great significance to ensure uninterrupted operations in customers of manufacturing and service industries relying on cloud-based computing resources. In this study, following a grid-based location approach, we present two mixed integer linear programming models for capacitated single-source data center location-allocation problems. The first model provides optimal locations, capacities and configurations of data centers, and allocation of demands to open facilities when there is no existing facilities in the region. Our second model considers the decision problem of meeting new demand when the existing demand is met by the already opened facilities. We term these newly arrived demand as replication demand, which results either from emergence of new users of existing customers at distant locations in the future, or as a means of increasing data resilience by creating data replication as a backup. To solve the decision problem for meeting primary and replication demand optimally, we propose a two-stage decision algorithm. The algorithm provides optimal locations, capacities and configurations for new data centers, capacity addition decisions to the existing facilities and subsequent allocation of demands. Both models and solution algorithm are implemented using AMPL programming language and solved with CPLEX solver. The models are found to be scalable and capable to provide high quality solutions in reasonable time.     

Location of health care facilities: An analytical approach

The problem of health facilities location is explored under a mathematical optimization approach. Several models are developed for the location of a generalized health facility system in a region in a manner that the selected criteria are optimized. Locational criteria are structured as a hierarchy of social, economic and political attributes and defined analytically using economic and utility theory. A planning framework, based on the models developed, is presented to aid the health planner in the formulation of health facility location decisions.     

Development of an integrated medical supply information system

The integrated medical supply inventory control system introduced in this study is a hybrid system that is shaped by the nature of medical supply, usage and storage capacity limitations of health care facilities. The system links demand, service provided at the clinic, health care service provider's information, inventory storage data and decision support tools into an integrated information system. ABC analysis method, economic order quantity model, two-bin method and safety stock concept are applied as decision support models to tackle inventory management issues at health care facilities. In the decision support module, each medical item and storage location has been scrutinised to determine the best-fit inventory control policy. The pilot case study demonstrates that the integrated medical supply information system holds several advantages for inventory managers, since it entails benefits of deploying enterprise information systems to manage medical supply and better patient services.     

美国城市增长管理的方法与启示

介绍美国主要的三类城市增长管理方法,即管理和控制城市增长区间和特点的方法;保护自然资源、环境质量和生态特征的方法;提供有效的公共基础设施的方法.分别对每一类方法进行了系统的介绍,进而指出对中国城市增长管理和土地利用管制的启示.     

Network flow-based strategies for identifying rail park-and-ride facility locations

Many cities are considering introducing or expanding rail service in an effort to diversify their modal splits. Park-and-rides are integral to this strategy because they represent private auto users’ access points to the system. Proper placement of such facilities is a strategic location decision, as it can conceivably decrease vehicular traffic on congested roadways while benefiting users. This paper models the decision to locate park-and-ride facilities in a network flow-based framework. From this perspective, optimal placement occurs at locations where vehicles will encounter facilities early during their journeys to a centralized area or major activity center. Locating park-and-rides in this fashion maximizes the chances of removing users from the network. These elements are demonstrated in three hypothetical placement scenarios that make use of synthetic network and traffic flow data. Results illustrate the functionality of our approach for identifying park-and-ride candidate locations. Lastly, implications of our work are discussed in light of broader planning concerns and practical demands on rail facility location.     

Location and service mix decisions for a managed health care network

For managers of managed health care organizations, the problem of designing a competitive multiple facility network cannot be solved by existing mathematical models. This paper thus presents a nonlinear integer model for determining a facilities design strategy that embodies the economic tradeoffs encompassed in a competitive strategy: minimizing cost and maximizing market share. The integrated location and service mix model determines the number, location and service offerings of facilities that maximize profitability in a two-level hierarchical referral delivery network where an organization's market share is represented by a multiplicative competitive interaction model. To demonstrate the usefulness of the proposed integrated model, a series of problems is solved by an interchange heuristic and compared to the solutions derived by a simpler approach that ignores market competition.     

Hedonic Model在二手房价格分析中的应用——以昆明市为例

以昆明市城区二手房为研究对象,利用Hedonic模型和统计学方法研究房价与特征属性的定量关系。结果表明半对数函数模型的拟合度最高,回归系数表明二手房区位特征中环线位置对房价的影响最大。住宅属性对房价影响程度依次是环线位置、轨道交通、物业管理费、容积率、教育配套、公交线路、装修程度、建筑面积。     

Predicting bankruptcy in the Texas nursing facility industry

Approximately 50% of nursing facilities in Texas petitioned for bankruptcy during the 1998–2004 period. Using a logit regression model tested for robustness, we find nursing facilities that are profit-seekers, chain members, pay higher than average wage rates, accept more intensive-care residents and obtain a larger than average portion of their funding from public sources are highly vulnerable to negative changes in regulatory policy decisions on Medicare and Medicaid reimbursement. Larger facilities having higher than average occupancy rates and quality of care are less susceptible to adverse decisions. The model correctly classifies a facility as either bankrupt or solvent in about 75% of cases. We also examine the duration of bankruptcy using accelerated failure-time models. It appears that the duration of bankruptcy depends on location, out-of-state ownership, length of ownership, volume of resident days supplied, total cost and proportion of revenues from Medicaid.     

Incorporating activity space and trip chaining into facility siting for accessibility maximization

Location models have been widely used to support locational decisions for various service provision. One common objective of location models has been to ensure maximal accessibility of sited facilities to demand populations. Accessibility evaluation in location models often assumes that trips originate from fixed locations (usually home) and are single purpose. These assumptions contradict the empirical evidence that suggests trips also commonly originate from non-home locations and may involve multiple stops. In this study, a new multi-objective location model is developed that extents the classic p-median problem (PMP) to account for a more realistic assessment of accessibility. Based on the individual accessibility assessment, notions of trip chaining and activity space are incorporated into the model development. In addition to fixed home locations, stops along chained trips are allowed for potential service site visits, and activity space is introduced as an additional dimension to evaluate accessibility of alternative opportunities. The effectiveness of the new model is demonstrated using an application in Tucson, AZ.     

基于层次分析法的战时后勤设施选址研究

分析战场环境下军事后勤设施选址决策的影响因素,构造选址评价指标体系的层次结构模型。基于层次分析法和群体决策理论,提出一种定性与定量相结合的战时后勤设施选址决策方法。并给出算例,演示具体的选址过程。研究表明运用层次分析法进行战时军事后勤设施选址,是合理、可行的,能够提高后勤设施选址决策的有效性和可靠性。