基于灰色聚类评估的配送中心选址模糊多目标优化模型

将多属性决策方法与最优化方法相集成,研究了多配送中心选址优化问题。首先采用灰色聚类决策计算各候选地定性属性的综合评估值。再以选定配送中心的评估值均值最大化、系统成本最小化,以及配送中心容量利用率最大化作为3个优化目标,建立一个考虑需求点模糊需求、供应点与候选配送中心容量限制的三级供应链系统多配送中心选址模型。该模型被描述成了一个多目标的非线性混合整数规划模型。采用机会约束规划对模糊需求进行清晰化处理,并应用目标加权的方法将问题转化为单目标问题。通过算例验证了所提模型的可行性。在实际工作中,可根据决策者权重偏好得出令人满意的结果。     

碳纤维拉伸工艺优化的多目标动态规划方法

将碳纤维的数字化加工优化问题按阶段划分为若干多目标决策子问题。以其中的拉伸过程为例,按拉伸的时间顺序将其划分为6个阶段,以原丝线密度、强度和断裂伸长率为优化目标,提出了一种碳纤维拉伸工艺优化的多目标动态规划方法。以实验数据为基础,拟合出产品性能与生产工艺的关系。采用专家打分,确定各拉伸阶段的权重,合理分配拉伸比。     

基于多目标决策的动车组部件分阶段预防性维护优化模型

对动车组部件维修周期的确定直接影响到部件运用时的可靠性及动车组的行车安全。以我国动车组检修制度为背景,选用非完美维修和更换两种不同的维修方式,并考虑到非完美维修后部件可靠度的加速衰退,建立了以维修时间和维修成本为优化目标的分阶段预防性维修模型。应用遗传算法对不同阶段内的维修间隔、维修次数和维修方式进行决策,并与等周期维修模型进行比较。研究结果表明,在满足部件可靠度要求的前提下,分阶段预防性维修模型相比于等周期维修模型能够有效缩短维修时间、降低维修成本,更具经济性。与单目标优化相比,多目标优化的联合决策可以根据检修部门的实际需要提供多种维修方案,有效协调部件的运用需求和维修需求。     

飞机移动生产线作业调度问题的启发式算法

飞机移动生产线作业调度问题是一种具有特殊约束的项目调度问题。综合分析了飞机移动生产线的作业顺序关序、资源约束、空间限制的多重特点,建立了以最小装配完工时间为目标的模型。将问题分为确定作业的优先顺序和选择作业人数的两个阶段进行决策,设计了由不同规则组合成27种启发式方法。通过比较启发式方法在250个测试问题集的表现,确定最有效的解决此问题的方法。     

产品平台与产品族协同架构的主从关联优化

自顶向下的产品族架构设计,需要首先决策产品平台的架构,同时关联考虑产品族的架构需求。以往的相关研究,主要采用"all-in-one"或两阶段的单层优化方法。根据问题属性,提出一种主从关联优化的设计理念与方法:建立了以产品平台架构设计为主、以相应产品族架构设计为从的0-1非线性双层规划模型;模型不仅能够求解出协同设计的产品平台和产品族关联优化方案,而且给出一种基于主从优化的交互式评价模式与方法;构建了模型求解的双层嵌套遗传算法及结合产品族特色的相关处理策略;以一个笔记本电脑产品族的案例对模型及算法进行说明,并将优化结果与两阶段单层优化进行了比较。     

基于随机需求的两级多期供应链网络规划模型

本文以三级供应链网络为例,研究了具有随机因素的,两级多期决策的供应链网络优化问题.优化的具体内容包括两个方面:供应链节点的选址和相应配送系统的设计.文章首先在现有研究成果的基础上,将模型设计拓展到多期决策领域.接下来,针对因素的随机性问题,应用了蒙特卡罗方法对随机因素进行了模拟和采样.最后,模型的目标函数不仅考虑了最小成本,同时还考虑了顾客满意度.对多目标模型的处理采用了e条件限制法.用这种方法的得到的供应链网络优化结果是一系列帕累托最优解,它使得决策者可以按照自己的偏好做出最后选择.     

技术知识供需双边匹配的两阶段决策分析方法

针对知识服务中技术知识供给与需求的双边匹配问题,给出了一种两阶段决策分析方法。首先,依据技术知识供给主体和技术知识需求主体的满意度建立了匹配矩阵,并利用匹配矩阵筛选双边组合,产生候选匹配对;在此基础上,考虑以技术知识供需主体的满意度最大为目标,构建了多目标优化模型,并使用基于函数隶属度的加权和方法将多目标模型转换为单目标模型进行求解,获得了相应的匹配结果。实例分析表明,本文给出的方法具有可行性和有效性。     

基于遗传算法的工程项目投资综合优化探讨

利用多目标优化理论、多属性效用函数理论建立了工程建设项目工期、成本和质量的综合均衡优化模型，在网络计划技术的基础上，用遗传算法对模型进行求解，可以得到最满意的决策方案和多个近似满意的备选方案，作为工程建设项目投资综合控制的目标。并应用实例对模型的可行性和实用性进行了验证。     

不确定环境下应急设施选址问题两阶段鲁棒优化模型

对于应急物流管理而言,应急物资集散中心选址是一个重要的决策要素。针对应急突发事件的不确定性特征,本文提出了一个应急设施选址问题两阶段鲁棒优化模型,以实现“预选址-重选址”两者的协同优化。第一阶段在需求和成本变动、设施损毁存在不确定因素的情况下,综合考虑选址策略在灾前规划、灾后反应、设施重建阶段的不同需求,建立了一种基于p-center的鲁棒“预选址”模型;第二阶段针对灾后新信息的获得,建立了一种基于反应式修复和调整策略的新建设施“重选址”模型。算例分析表明,本文模型对于应急设施选址问题比传统p-center模型更为合理有效     

考虑分割配送的易腐品一体化库存路径问题

一个供应商用多个同质车辆给多个零售商配送一种易腐品,满足多个周期中零售商的需求,决策计划期内零售商的到货计划、供应商的生产计划以及车辆路径问题以最小化系统总成本。考虑质量时间窗、载重成本、车辆返回时间间隔等因素,建立混合整数规划模型,将模型分为一个主问题、两个子问题,采用两阶段启发式算法和配送量调整机制来进行求解,通过数值算例和灵敏度分析验证了模型和算法的有效性。     

鄂尔多斯盆地油气勘探开发的实践与可持续发展

鄂尔多斯盆地是我国近10年来石油天然气产量增长最快的盆地,目前已经成为我国第二大油气生产盆地和第一大天然气产区。概述了鄂尔多斯盆地油气勘探开发的历史,总结了盆地发展形成的重要认识、主要技术、开发管理模式、油气产量和取得的经济社会效益,从发展规划、油气资源、非常规油气资源和其他资源方面探讨了盆地发展前景,并对盆地可持续发展提出了建议。     

Using integrated process and microeconomic analyses to enable effective environmental policy for shale gas in the USA

As one of the largest consumers of energy and emitters of greenhouse gases in the world, the USA must balance energy demand and security with environmental responsibility. Recently, shale gas has emerged as a promising element toward a solution to this dilemma. Currently, shale gas production is regulated under the same rules that govern traditional oil and gas operations, without consideration for the unique environmental challenges associated with the unconventional gas extraction process. It involves small independent operators that typically utilize the most cost-effective extraction processes without necessarily prioritizing the environmental impact of their operations. As a result, opposition to shale gas extraction threatens the continuity and sustainability of the shale gas industry. The negative externalities and information asymmetry associated with this market continue to be captured in a price of natural gas which is not inclusive of the environmental costs of the extraction processes. The objective of this work is to determine the environmental policies that will lead to sustainable shale gas production. A hierarchical approach is developed to benchmark current technologies and to generate, assess and select technologies and policies that overcome market hurdles while addressing EHSS objectives. The approach analyzes the technical and microeconomic impacts of environmental remediation techniques and then takes a multipronged policy approach which supports the microeconomic, environmental, health and safety goals. To illustrate the usefulness of the proposed approach, a case study is solved for the Barnett Shale play to assess at the microeconomic and environmental implications of environmental remediation technologies for shale gas operations. Based on the results of the analysis, technology changes create both economic and environmental benefits for operators indicating a market failure resulting in the priceless favorable technologies do not reflect their impact on the environment. The market failures in the process are analyzed and four policy alternatives to the status quo are evaluated against four policy goals. The primary recommendation resulting from the analysis, the Comprehensive policy alternative, uses a phased approach to drive ongoing innovation in the shale gas industry, stimulate demand for natural gas and reduce the information asymmetry. The implementation of this policy is then applied to an economic and environmental model of a cluster of wells in the Barnett Shale to determine how the policy would be implemented.     

Design and analysis of biodiesel production from algae grown through carbon sequestration

This paper addresses the design and techno-economic analysis of an integrated system for the production of biodiesel from algal oil produced via the sequestration of carbon dioxide from the flue gas of a power plant. The proposed system provides an efficient way to the reduction in greenhouse gas emissions and yields algae as a potential alternative to edible oils currently used for biodiesel production. Algae can be processed into algal oil by various pathways. The algal oil can then be used to produce biodiesel. A flowsheet of the integrated system is synthesized. Then, process simulation using ASPEN Plus is carried out to model a two-stage alkali catalyzed transesterification reaction for converting microalgal oil of Chlorella species to biodiesel. Cost estimation is carried out with the aid of ICARUS software. Further economic analysis is performed to determine profitability of the algal oil to biodiesel process. The results suggest that, for the algal oil to biodiesel process analyzed in this study, factors such as choosing the right algal species, using the appropriate pathway for converting algae to algal oil, selling the resulting biodiesel and glycerol at a favorable market selling prices, and attaining high levels of process integration can collectively render algal oil to be a competitive alternative to food-based plant oils.     

A simple transient numerical model for heat transfer and shape evolution during the production of rings by centrifugal spray deposition

Centrifugal spray deposition, the atomisation of a liquid metal by centrifugal force and the subsequent collection of the atomised droplets on a reciprocating collector, is currently being developed for the production of high performance Fe, Ni and Ti based ring-shaped components for use in aerospace and gas turbine containment applications. The process combines the technical, economic and metallurgical benefits of more conventional gas-assisted spray forming techniques with the advantage that it can easily operate under vacuum, reducing potential problems from gas entrapment and thermally induced porosity. In order to aid process development, understanding and optimisation, a transient numerical heat and mass transfer model has been developed that is capable of predicting the evolution of the deposit temperature distribution during spraying. The model has been validated experimentally using thermocouple measurements obtained during the production of 35 kg (340 mm diameter) IN718 rings and qualitative correlations have been observed between the predicted data and the type/distribution of porosity and second phase precipitates in the deposit. The model is currently being further developed and integrated with droplet size distribution and cooling models to provide a better insight into the physics and operational parameters which control deposit shape and microstructure.     

Integrating AHP with QFD for robot selection under requirement perspective

Selection of a robot is an important task, as improper selection may adversely affect a firm's production by reducing the quality of the product, thereby reducing productivity as well as profitability. To effectively select a robot for a specified job, several factors have to be considered. The objective of this paper is to explain how, using a combined AHP/QFD model, the authors are able to determine if the deployment of robots in industry helped in performance enhancement from requirement perspective. Incorporating a simple and novel cost factor measure in the proposed integrated AHP/QFD model aids justification of the implementation of a robotic system in a manufacturing firm from an economic point of view also. The proposed integrated approach also identifies technical requirements followed by customer requirements. In this paper, an integrated model combining AHP and QFD has been delineated for the industrial robot selection problem. Seven technical requirement factors have been considered for the case study.     

Integrated production maintenance and quality model for imperfect processes

In this paper, we develop an integrated model for the joint optimization of the economic production quantity, the economic design of x¯-control chart, and the optimal maintenance level. This is done for a deteriorating process where the in-control period follows a general probability distribution with increasing hazard rate. In the proposed model, Preventive Maintenance (PM) activities reduce the shift rate to the out-of-control state proportional to the PM level. Compared to the case with no PM, the extra cost of maintenance results in lower quality control cost which may lead to lower overall expected cost. These issues are illustrated using an example of a Weibull shock model with an increasing hazard rate.     

Floating production storage and offloading systems’ cost and motion performance: A systems thinking application

Floating production storage and offloading (FPSO) units increasingly represent a practical and economic means for deep-water oil extraction and production. Systems thinking gives a unique opportunity to seek a balance between FPSO technical performance(s), with whole-cost; stakeholder decision-making is charged to align different fit-for-use design specification options’ that address technical-motion(s), with respective life-cycle cost analyses (LCCA). Soft system methodology allows situation based analyses over set periods-of-time by diagnosing the problem-at-hand; namely, assessing the antecedents of life-cycle cost relative to FPSO sub-component design alternatives. Alternative mooring- component comparisons for either new-build hulls or refurbished hulls represent an initial necessary consideration to facilitate extraction, production and storage of deep-water oil reserves. Coupled dynamic analysis has been performed to generate FPSO motion in six degrees of freedom using SESAM DeepC, while life-cycle cost analysis (LCAA) studies give net-present-value comparisons reflective of market conditions. A parametric study has been conducted by varying wave heights from 4 – 8 m to understand FPSO motion behavior in the presence of wind and current, as well as comparing the motions of turreted versus spread mooring design alternatives. LCCA data has been generated to compare the cost of such different mooring options/hull conditions over 10 and 25-year periods. Systems thinking has been used to explain the interaction of problem variables; resultantly this paper is able to identify explicit factors affecting the choice of FPSO configurations in terms of motion and whole-cost, toward assisting significantly with the front-end engineering design (FEED) phase of fit-for-purpose configured FPSOs, in waters off Malaysia and Australia.     

基于GA-ANFIS在石灰矿技术经济系统中的参数优化研究与应用实践

为掌握水泥原料矿山系统中的技术经济参数对矿石成本影响的关联规律性，首先运用自适应模糊神经网络对矿山技术经济系统建模，再用并行遗传算法对模型求解，得到了确保矿石成本最小的各项最优技术经济指标，为提高矿山生产管理与经济效益提供了重要的参考价值。     

Port-of-entry safety via the reliability optimization of container inspection strategy through an evolutionary approach

Up to now, of all the containers received in USA ports, roughly between 2% and 5% are scrutinized to determine if they could cause some type of danger or contain suspicious goods. Recently, concerns have been raised regarding the type of attack that could happen via container cargo leading to devastating economic, psychological and sociological effects. Overall, this paper is concerned with developing an inspection strategy that minimizes the total cost of inspection while maintaining a user-specified detection rate for “suspicious” containers. In this respect, a general model for describing an inspection strategy is proposed. The strategy is regarded as an (n+1)-echelon decision tree where at each of these echelons, a decision has to be taken, regarding which sensor to be used, if at all. Second, based on the general decision-tree model, this paper presents a minimum cost container inspection strategy that conforms to a pre-specified user detection rate under the assumption that different sensors with different reliability and cost characteristics can be used. To generate an optimal inspection strategy, an evolutionary optimization approach known as probabilistic solution discovery algorithm has been used.     

基于多层可行方向法液体静压转台优化设计

为提高液体静压转台的动力学性能, 该文从N-S方程着手, 计算了液体静压油腔处的动压承载力。通过供油压力计算了同位置处的静压承载力, 利用动压承载力和静压承载力的相互叠加, 计算了液体静压导轨综合承载力, 继而推导了油膜刚度的计算公式。在此基础上, 建立了以综合承载力和油膜刚度为目标函数, 以液体静压转台的振动基频为约束的优化模型, 利用响应面方法和分层可行下降方向法对优化模型进行了求解, 并对优化后的设计进行了瞬态冲击载荷下加工精度的验证, 从而为工程设计提供了理论依据。