A multi-objective healthcare inventory routing problem; a fuzzy possibilistic approach

This paper presents a new multi-objective mathematical model to address a Healthcare Inventory Routing Problem (HIRP) for medicinal drug distribution to healthcare facilities. The first part of objective function minimizes total inventory and transportation costs, while satisfaction is maximized by minimizing forecast error which caused by product shortage and the amount of expired drugs; Greenhouse Gas (GHG) emissions are also minimized. A demand forecast approach has been integrated into the mathematical model to decrease drug shortage risk. A hybridized possibilistic method is applied to cope with uncertainty and an interactive fuzzy approach is considered to solve an auxiliary crisp multi-objective model and find optimized solutions.     

Transportation network reliability in emergency response

Distribution of humanitarian supplies is vital in saving lives during disasters. Investment in retrofitting critical transportation links reduces casualties as intact links improve flow of relief supplies. In finding critical links, link importance values are derived using the concept of network reliability. A network improvement problem is then solved to minimize death toll. To increase practicality, a heuristic algorithm is proposed to solve real size problems. Results show that initial incremental investments in network improvement are more profound in reducing the death toll than higher budget increments. Moreover, higher relief inventories reduce the death toll when the network is reliable.     

An integer programming approach to the bloodmobile routing problem

Every day, a blood center must determine a set of locations among a group of potential sites to route their vehicles for blood collection so as to avoid shortfalls. In this study, a vehicle routing problem is modeled using an integer programming approach to simultaneously identify number of bloodmobiles to operate and minimize the distance travelled. Additionally, the model is extended to incorporate uncertainty in blood potentials and variable durations in bloodmobile visits. Optimal routings are determined using CPLEX solver and branch-and-price algorithm. Results show that proposed algorithm solve the problem to optimality up to 30 locations within 3600 s.     

A decision framework for successful private participation in the airport sector

As private participation in public airports becomes a global trend, there are a number of concerns and debates over the conflicting interests of the private and public sectors. For instance, the private sector's interest in maximizing profits often opposes the public sector's interest in protecting the public interest and social welfare. In this paper, we reframe the conflict in terms of principal-agent theory, and inform policymakers to understand public-private management problems in a broader context. Firstly, we demonstrate how various ownership and governance structures shape the private participation based on (1) ownership-type, (2) mode of ownership shift, and (3) ex-post government control. Secondly, we then highlight that this process should be context-based, and examine the recent case of Incheon International Airport (IIA) in South Korea to illustrate the importance of contextual factors. Lastly, we provide comprehensive recommendations to policymakers involved in bringing private partners into the airport sector, which include setting a clear agenda, exercising a reasonable level of control, understanding the sharing of risk and responsibility under different structures, and assessing technical, economic and political factors that may affect the policy outcome.     

A hybrid multi-objective approach to capacitated facility location with flexible store allocation for green logistics modeling

We propose an efficient evolutionary multi-objective optimization approach to the capacitated facility location–allocation problem (CFLP) for solving large instances that considers flexibility at the allocation level, where financial costs and CO₂ emissions are considered simultaneously. Our approach utilizes suitably adapted Lagrangian Relaxation models for dealing with costs and CO₂ emissions at the allocation level, within a multi-objective evolutionary framework at the location level. Thus our method assesses the robustness of each location solution with respect to our two objectives for customer allocation. We extend our exploration of selected solutions by considering a range of trade-offs for customer allocation.     

Integrated Berth Allocation and Quay Crane Assignment Problem: Set partitioning models and computational results

Most of the operational problems in container terminals are strongly interconnected. In this paper, we study the integrated Berth Allocation and Quay Crane Assignment Problem in seaport container terminals. We will extend the current state-of-the-art by proposing novel set partitioning models. To improve the performance of the set partitioning formulations, a number of variable reduction techniques are proposed. Furthermore, we analyze the effects of different discretization schemes and the impact of using a time-variant/invariant quay crane allocation policy. Computational experiments show that the proposed models significantly improve the benchmark solutions of the current state-of-art optimal approaches.     

论传销及其优势和问题

近年来,传销越来越引起了人们的重视,成为继股票、房地产之后又一社会热点。本文客观地解释了什么是真正意义上的传销及其实质;分析了传销方式本身所具有的强大优势;也指出了现在我国传销业发展中存在的问题,并简单探讨了解决这些问题的办法。     

高校教学管理中存在的问题与对策

加强教学管理是提高教学质量的基础工作.文章结合目前高校教学管理中存在的一些问题,就如何强化教学管理、提高教学质量提出一些探讨性的意见.     

城市集中供热行业发展问题分析与内在规律探讨

城市集中供热行业发展存在体制与责任、经营自主权、信息不对称、价格体制不科学、经济外部性、运行技术落后、经营考核缺失、区域垄断保护、产权不清晰、补贴维运行等现实问题。基于供热行业的区域自然垄断属性和运行周期的阶段性特征,揭示城市集中供热经营运行的内在规律：市场供给是有效的,特许经营是可行的,政府监管是必要的,按照价值定价是必然的,企业整合是符合潮流的,计量收费是科学的,信息化平台是基础的。     

时变环境下选址问题的一个启发式算法

配送中心选址作为物流管理中的一个重要研究问题受到广泛重视。然而,文献中所涉及的选址模型大都是静态的,即沿一条路径行进时所需的成本(或时间)是与出发时间无关的函数。但在实际生活中,它往往是会随时间的变化而变化的,这类问题被称为时变环境下的选址问题。文中讨论了时变环境下的单配送中心到多个零售点带容量约束的选址问题。由于该问题是NP-完备的,我们给出了一个启发式算法。