Counterpart Models in Facility Location Science and Reserve Selection Science

Five classes of zero–one programming models for discrete facility location problems are compared to counterpart models for the selection of conservation reserves. The basic problem of siting facilities to cover demand for services is analogous to the problem of selecting reserves to support species diversity. The classes of models include the set covering and maximal covering models, as well as models for backup and redundant coverage. Issues of reliability and uncertainty are addressed by chance constrained covering models and maximal expected covering models. Exact and heuristic solution approaches are discussed. Multi-objective and economic issues are considered.     

基于成本-效益准则的高层RC框架结构优化设计(Ⅰ)——方法

成本-效益准则是基于性能的抗震设计的重要原则,该准则在设计中除了考虑技术要素外,还考虑经济、社会等诸多因素,它所追求的设计目标为结构在其寿命周期内的总造价最小.因此,结构全寿命造价评估是基于性能的抗震设计的基本问题.在已有全寿命造价优化模型的基础上,提出了三目标函数全寿命造价优化模型.与已有的全寿命造价模型相比,该模型除考虑结构初始造价、损失期望外,还考虑了反映结构设计与施工复杂性的构件截面类型数量;另外,还将结构在其运行期间的检查、维护费用及由于优化导致建筑使用面积变化所引起的租金收益影响也列入到结构全寿命造价中.最后,基于所提出的优化模型,给出了以多目标遗传算法为搜索引擎、运用MATLAB语言开发的高层RC框架结构基于成本-效益准则的自动优化程序流程图.     

A meta‐heuristic approach for supporting adaptive disassembly sequencing using a multi‐objective concept

One of the key features of environmentally conscious manufacturing has been the efforts to promote product recycling and remanufacturing. Efficient material re‐utilisation through product disassembly to retrieve the desired parts and/or subassemblies is one rational approach. This is because it can promote the conservation of both material and energy resources whilst concurrently reducing environmental impact. However, because manufactured products may be made from many components, disassembly load becomes a critical factor that may obstruct the recovery of materials. Accordingly, it is essential to develop a practical method for deriving a disassembly plan to decrease such load, and to endow a certain value to the product at the end of its life cycle. With this understanding, the authors have developed a practical procedure to produce an adaptive disassembly strategy. The authors have applied a meta‐heuristic method known as genetic programming (GP) as a search engine to derive the adaptive disassembly sequence together with a multi‐objective optimisation method termed MOON^2R. The authors have also proposed a hierarchical sequencing method to cope with large/complex products and added several ideas to increase the applicability associated with the interests in disassembly of hazardous and/or valuable parts, and alternative disassembly actions. Through numerical experiments, the authors examined the effectiveness of the proposed approach by showing its support for relevant planning and design decisions for product recycling and remanufacturing from various viewpoints.     

基于参数不确定性的地下水污染治理多目标管理模型

引入随机Pareto控制排序和随机小生境技术,提出基于参数随机变化的改进小生境Pareto遗传算法,用于求解不确定性条件下地下水污染治理多目标管理模型.同时,利用顺序高斯条件模拟的蒙特卡罗方法,结合不确定性分析和风险评估,分析不同渗透系数条件点数对污染物运移结果不确定性和污染风险评价的影响.最后将该方法应用于一个考虑渗透系数为随机变量的二维地下水污染修复算例中.结果分析表明,该方法可为地下水污染治理提供变异性较小的Pareto管理策略,是一种稳定可靠的多目标随机优化方法.     

考虑洪涝灾害风险的城市应急避难场所选址研究*

为解决洪涝灾害下城市应急避难场所选址优化问题,将洪涝灾害风险评估与选址模型相结合。首先,运用灰色模糊综合评价法对洪涝灾害风险进行评价,得到洪涝灾害风险综合指数。然后,将综合指数归一化处理后作为权重引入疏散距离最小化和覆盖人口最大化的目标函数,结合最小化避难所数量,以最大服务范围、容量作为约束,构建引入洪涝灾害综合风险权重的多目标应急避难场所选址优化模型,并采用遗传算法对模型进行求解。最后,以武汉市作为实证研究对象验证模型的科学性和有效性。研究结果表明:在考虑洪涝灾害风险的情况下,应急避难场所选址方案可在接近最优解的情况下达到最优。研究结果可为城市防洪应急避难场所布局优化提供参考。     

流域主体功能优化与黄河水资源再分配

立足流域主体功能优化概念内涵,系统性解析流域各类主体功能目标,基于流域主体功能评价指标体系建立以主体功能优化为目标导向的流域主体功能水资源分配机制,通过遗传算法求解多目标优化模型得到2017年黄河流域9省、自治区的四类水资源分配方案。研究结果表明：（1）流域主体功能实现水资源分配机制,使黄河流域最大可能节水23.01亿m³。（2）流域主体功能水资源分配机制给黄河流域主体功能实现分别带来4344.48亿元的生产功能增量、991.35亿元的生态功能价值增量,可多承载8194.84万人口。（3）减少宁夏和山东的农业用水及内蒙古工业用水分配对黄河流域水资源优化分配至关重要。     

Evaluation of aquatic rehabilitation technologies for polluted urban rivers and the case study of the Foshan Channel

An index system for evaluation of technologies for urban river rehabilitation was proposed and discussed. The index system includes indicators of cost, resources, environmental improvement, and social effects. The calculation method for an objective value of each index based on its attributes and weights was presented. The Foshan Channel, which is a seriously polluted, black and malodorous urban river in Foshan City, China, was selected as a case study. The values of the attributes and the weights of the indices for the Foshan Channel were determined. The technologies for the rehabilitation of the Foshan Channel were evaluated based on this index system. Finally, a rehabilitation scheme for the Foshan Channel was proposed.     

Assessing livelihood for improvement: Samanalawewa reservoir environs,Sri Lanka

This paper explores household (HH)-level livelihood dynamics and determinants since construction of the Samanalawewa Hydroelectricity Reservoir (SHER) in the Samanalawewa watershed, Sri Lanka. The research is based on data from a structured questionnaire survey of 201 randomly selected households (HHs) in upstream and downstream areas. Livelihood dynamics at two separate points in time (1988 and 2008) were assessed based on a sustainable livelihood framework (SLF). Impact of livelihood determinants on livelihood was analysed using factor and regression analysis techniques, followed by an optimisation procedure to suggest requirements in selected significant determinants to improve the livelihood of various categories of farm HH. In both upstream and downstream areas, livelihood assets, viz. physical, social and human capital, increased significantly, while access to natural and financial capital decreased significantly and slightly, respectively, during last two decades. The factor analysis extracted six factors in the upstream area and seven in the downstream area. The derived regression models show that nine variables in the upstream area and ten in the downstream area are major determinants of HH livelihood. Based on optimisation results, policy implications are discussed in relation to needed improvements in livelihood determinants to improve overall livelihood of HHs.     

应急救援多目标时限指派模型

为实现应急救援队伍的合理派遣,对应急救援队伍的救援效率、救援物资消耗、最佳救援时间等因素进行分析。突出应急救援的时效性和救援目标的多属性特征,提出在保证应急救援最短时限的前提下,以应急救援效率最大化、物资消耗最小化为优化目标,构建最短时限应急救援多目标指派模型。采用线性加权和法将多目标化为单目标决策问题,运用两阶段法对模型进行求解。数值计算结果表明:最短时限的引入能有效实现应急救援队伍合理、公平派遣。