Development and Comparison of Hybrid Genetic Algorithms for Network Design Problem in Closed Loop Supply Chain

This paper presents four different hybrid genetic algorithms for network design problem in closed loop supply chain. They are compared using a complete factorial experiment with two factors, viz. problem size and algorithm. Based on the significance of the factor “algorithm”, the best algorithm is identified using Duncan’s multiple range test. Then it is compared with a mathematical model in terms of total cost. It is found that the best hybrid genetic algorithm identified gives results on par with the mathematical model in statistical terms. So, the best algorithm out of four algorithm proposed in this paper is proved to be superior to all other algorithms for all sizes of problems and its performance is equal to that of the mathematical model for small size and medium size problems.

Literature Review on Network Design Problems in Closed Loop and Reverse Supply Chains

The productivity of an organization is very much affected by non-value adding activity like logistics, which moves the resources from suppliers to factory, raw materials/semi-finished items within the factory and finished goods from factory to customers via a designated distribution channel called as forward logistics. In some cases, parts of the products such as automobiles, computers, cameras, mobile phones, washing machines, refrigerators, garments, footwear and empty glass bottles of beverages, etc. will be brought back to the factories as a product recovery strategy through reverse logistics network which is integrated in a sustainable closed loop supply chain network. So, it is highly essential to optimize the movement of the items in the reverse logistics network. This paper gives a comprehensive review of literature of the design of networks for the reverse logistics as well as for the reverse logistics coupled with forward logistics. The contributions of the researchers are classified into nine categories based on the methods used to design the logistics network.

Pricing and decision of carbon emission reduction for closed-loop supply chain considering carbon trading mechanism

To determine the optimal pricing and carbon emission reduction decision, a closed-loop supply chain with a manufacturer and a retailer is investigated. In this system, the manufacturer manufactures new products and remanufactures used products while the retailer is responsible for selling new products and remanufactured products. The profit functions of the manufacturer and the retailer are developed, and the corresponding solution formulae for decision variables are given by the Stackelberg game model. Finally, a numerical example is given, and the optimal wholesale price, retail price, carbon emission reduction and others are obtained. Through the sensitivity of the unit carbon allowance price, some significant managerial insights are derived.

Remanufacturing Closed-Loop Supply Chain Model with Radio Frequency Identification Affecting Recycling Rate

In order to construct a resource-saving and environment- friendly society, the advantages of radio frequency identification （RFID） were considered. And it put forward the idea of introducing RFID in the recycling activities of waste products. Taking into account such elements as the technical level of RFID, cost saving from remanufacturing and the cost of RFID tags, both centralized and decentralized supply chain models with different participants in waste product collection were created, in order to determine the optimal pricing strategy and RFID technical level. In the end, sensitivity analyses were conducted to analyze the impacts of scaling parameter for additional increased recovery rate with RFED on pricing and RFID technology level, and impacts of cost saving on the profits of participants in different remanufacturing closed-loop supply chain models.

Improving the Performance of Urban Waste Management Systems in the Context of a Closed-Loop Supply Chain

The saving of non-renewable energies, as well as the reduction of emissions into the environment, are two crucial objectives of industrial production. The recovery of post-consumer products associated with the use of end-of-life products is part of a context of optimization of these objectives. This recovery maximizes the use of resources from end-of-life products in a circular logic while recording the environmental footprint. This study considers a recycling strategy adapted to the need and urgency to reduce greenhouse gas emissions caused by global warming. The proposed model aims to optimize the profits of the circular manufacturing strategies while minimizing operational costs (collection, sorting, recycling), transport, GHG emissions and recycling. In this paper, a compromise between the gains of CM and the costs associated with it was studied. The robustness of the designed model was tested using a case study based on real-world scenarios. A sensitivity analysis was carried out to study the impact of the emission cost on the overall objective, considering the two options currently offered to industries. The obtained results support companies to take the ecological aspect into account and integrate sustainable development into their strategic axes for their logistics supply chains.

Dynamic Pricing Model for the Operation of Closed-Loop Supply Chain System

A class of closed-loop supply chain system consisting of one manufacturer and one supplier is designed, in which re-distribution, remanufacturing and reuse are considered synthetically. The manufacturer is in charge of recollecting and re-disposal the used products. Demands of ultimate products and collecting quantity of used products are described as the function of prices and reference prices. A non-linear dynamic pricing model for this closed-loop supply chain is established. A numerical example is designed, and the results of this example verified the model’s validity to price for the operation of closed-loop supply chain system.

A closed-loop Supply Chain Network Equilibrium Model with Fuzzy Demand under Production Capacity Constraints and Price Rigidities

A closed-loop supply chain network equilibrium problem is examined,which consists of mutual competitive manufacturers with production capacity constraints and retailers with fuzzy market demands,mutual competitive collectors as well as a binding price ceiling of the commodities.By utilizing the credibility measure of fuzzy event,variational inequality and Lagrange dual theory,the optimum behaviors of manufactures,retailers,collectors and consumers are described.Therefore,the supply chain network equilibrium model is established.Numerical examples were given to illustrate the impact of production capacity constraints and price ceiling on the network equilibrium pattern.The results show that the shortage of commodities in consumer market will be more serious,the wholesale price of product and purchase price of waste products rise,the profits of retailers decrease,the profits of manufacturers and collectors increase as the government gradually reduce the binding price ceiling on competitive markets,and the trend will be more obvious in the existence of production capacity constraints at same time.

Operating Analysis of the Closed Supply Chain of Green Agricultural Products Based on Logistics Center

This thesis gives the overview of concept and constitution of the closed supply chain of green agricultural products based on logistics center,and the necessity of regarding logistics center as core enterprise.Meanwhile,it analyzes the function of logistics center of agricultural products,namely functions of exchange,collection,distribution,storage and transportation.It also poses the prerequisites of logistics center.The logistics center of agricultural products must have stable profit expectancy,prominent scale,strong appealing power,capacity of bearing market risk and basic thoughts of supply chain management.The functional design of the closed supply chain of green agricultural products has been discussed in 5 aspects,namely logistics center,production base,providers of means of production,retailer and consumer.The operating thoughts of the closed supply chain of green agricultural products based on logistics center are put forward on the basis of the research of operating objective and service target of supply chain as follows:first,based on local principal agricultural products,the logistics center mainly distributes the massed agricultural products;second,it is necessary to choose appropriate strategic cooperative partners to sign contract;third,the operating procedure of supply chain entails bringing in professional managerial talents of supply chain;finally,the relationships of supply chain should be maintained.

Researches on Risk Evaluation of Green Agro-product Closed Supply Chain

Closed supply chain is a superior form of management model of chain supply and an effective means of improving the modernization of agro-product circulation. Based on the research results of the current literatures on supply chain risk and agro-product supply chain, related subjects of the agro-product closed supply chain involving production, management and consumption are studied and analyzed and the primary risking factors in the supply chain system are classified as environmental risk, system risk, information risk, management risk and quality risk. Risk of agro-product closed supply chain is evaluated by using the method of fuzzy comprehensive evaluation and the values are acquired. The result shows that risk of agro-product closed supply chain is moderate with relatively high risk, which basically accords with the present actual situations. It can be seen from the index weights of various levels that the key first-level indices influencing the risks are system risk, information risk, quality and safety risk and the key second-level are the coordinating and controlling ability of core enterprises, the implementation of information traceability and the construction of quality safety system. Therefore, risk of agro-product closed supply chain should be reduced by taking prevention and controlling measures mainly from these aspects.

增程式电动拖拉机动力电池供电系统研究

增程式电动拖拉机具有节能减排、续航时间长等优点,但现有动力电池组电压等级较低,无法满足增程式电动拖拉机整机直流母线电压需求。为此,针对增程式电动拖拉机整机500 V电压平台需求,研究了其动力电池供电系统,完成了动力电池供电系统硬件设计和控制设计,最终利用MatLab/Simulink进行了仿真验证。仿真试验方面,所设计的动力电池供电系统实现了从320 V到500 V良好的升压稳压控制与闭环直流电源供电效果,能够适应与增程器等其他电源并联均流供电需求,动力电池供电系统具有良好的动态性能和稳态性能,满足稳定供电需求。

Method with reliable accuracy and fast speed for measuring operational current of HTS NI closed-loop coils in steady persistent-current-mode

This study proposes a method for measuring the operational current of high temperature superconducting(HTS)non‐insulation(NI)closed‐loop coils,which operate in the steady persistent‐current‐mode(PCM).HTS NI closed‐loop coils are promising for many easily‐quenching direct‐current(DC)applications,where their performance is determined by magnetomotive forces,total number of turns,and dimensions.As the primary interface parameter in an application system,the operational current must be accurately and rapidly measured.Generally,this is achieved by dividing the measured magnetic field by the coil constant.However,even if the influence of the screening current induced field(SCIF)is not considered,existing methods for the coil constant may be disturbed by the performance and location of Hall sensors,or experience a long measuring period.Therefore,a relatively accurate and fast method is proposed in this study,which is based on adjusting the output current of the adjustable power supply and monitoring the coil voltage as an indicator.The proposed method was validated through experiments and simulations using an equivalent circuit model coupled with a finite element method(FEM)model,and its current accuracy can be equivalent to the resolution of the employed power supply.It was demonstrated that this method reduced the requirements for Hall sensor’s performance and location,and has a more reliable accuracy in contrast to the simulation method.Compared to the experimentally conventional method,the proposed method presents a significantly faster speed.The impact of the SCIF was considered and proven to be negligible for the tested pancake coils.Even for coils whose coil constant vibrates owing to the SCIF,this method can be adapted to directly measure various operational currents.Furthermore,it was demonstrated that the measurement error can be influenced by the current discrepancy among turns when the coil is not in the steady PCM,and a procedure for reducing this error was proposed.

Design of Controller for New EAST Fast Control Power Supply

The effectiveness of the magnetic confinement of plasma can be improved by elongat- ing the plasma cross-section in tokamak devices. But elongated plasma has vertical displacement instability, so a feedback control system is needed to restrain the plasma＇s vertical displacement. A fast control power supply is needed to excite the active feedback coils, which produces a magnetic field to control the plasma＇s displacement. With the development of EAST, the fast control power supply needs to keep on enhancing the fast response and output current. The structure of a new power supply is introduced in this paper. The method of multiple inverters paralleled with the current sharing reactor is presented to meet the need for large current and fast control. According to the design demands of the EAST fast control power supply, the adjuster of the current close loop is applied to the inverter, which can advance its ability to restrain the loop current in low frequency and DC output. The result of the experiment confirms the validity of the proposed scheme and control strategy.

Process Signatures as a Measure for Loopless Production

Using control and repairing loops to remove production errors is not the only solution to increase the manufacturing yield. The production of errors can also be directly avoided, prevented or eliminated, even as early as in the planning phase. This paper suggests that the idea of Process Signatures can help to achieve Loopless Production. Loopless Production offers an option to guarantee the production quality towards the vision of the zero-defect manufacturing. It is considered that closed loops are used in a production process chain to identify and to correct the unknown and the systematic errors. These errors can actually be avoided through specifically adjusted or optimal arranged production processes. This puts a higher demand on the understanding of processes, which involve various energy-material interactions. This demand can be met via Process Signatures which aims to develop a process-independent description method of effects of processes. A supportive relationship is foreseen between Process Signatures and Loopless Production. The combination of these two ideas shall allow the simplification of the work for the rationalization of process sequences, the streamlining of closed loops as well as the selection of optimal substitute processes.

双利他偏好下再制造闭环供应链的差异化定价决策

为了给出制造商和零售商双利他偏好下再制造闭环供应链的差异化定价决策,针对无利他偏好、单制造商利他偏好、单零售商利他偏好和双利他偏好4种决策模式,比较分析得出双利他偏好对闭环供应链差异化定价决策和渠道效率的影响。研究发现,增加零售商利他偏好程度会增加新产品和再制造产品批发价;增加双方的利他偏好程度会降低新产品和再制造产品零售价,增加市场需求;增强利他偏好程度会增加废弃产品回收数量,有利于回收再制造;提高制造商和零售商的利他偏好程度将减少自身收益而增加对方收益,同时提升渠道效率;双利他偏好有利于提高闭环供应链整体利润和效率,且比单一利他偏好产生的影响更加显著。

低碳视角下集成式纺织服装闭环供应链运作决策

纺织服装产业的蓬勃发展,不仅有效带动了社会经济的快速发展,同时也造成了废旧服装数量的日益剧增。为有效提高废旧服装回收效率及其利用率,兼顾供应链整体运营与生态环境的目标,文章设计分析了一个由供应商、制造商和零售商组成的三级纺织服装闭环供应链网络,其中零售商集成废旧服装的统一回收,制造商集成废旧服装的统一分类及再利用废旧服装的加工处理。鉴于服装回收处理过程中碳排放量高且分布不均这一现实问题,引入碳配额机制,以供应链整体收益和成本为目标,建立一个双目标决策优化模型,并对模型设计了约束求解方法。最后通过数值实验说明了本文所建模型的有效性和相应运营决策方案的合理最优性。相关研究结果表明:废旧纺织服装的回收处理尽管需要一定的运营成本,但从长期运营视角来看,其能够给供应链整体带来较大的潜在收益。零售商和制造商的集成化运营模式不仅可有效的降低供应链的整体运营成本,同时亦可有效提升供应链整体的协同运作效率。合理的碳配额机制可有效激励相关成员企业去绿色低碳运营,进而提升自身竞争力和可持续发展能力。相关研究成果不仅具有一定的理论价值,同时对政府和服装产业制定合理的碳配额机制,设计构建纺织服装闭环供应链网络具有一定的指导和借鉴意义。

考虑品牌优势的回收商生产模式研究:再制造或翻新

研究品牌优势对回收商生产模式选择的影响机制,并基于三方博弈模型,运用KKT条件等方法分析不同品牌优势下,回收商选择再制造或翻新的决策条件和利益分配结果。结果表明,在品牌优势较低的情况下,回收商的生产模式选择会依赖回收成本。当回收成本较低时,全部翻新是回收商最优策略,但这会损害品牌制造商和品牌零售商的利益;当回收成本适中时,回收商倾向于部分翻新,此时品牌零售商可以从中获益,但品牌制造商会受到冲击;当回收成本较高时,回收商翻新威胁小,品牌制造商和品牌零售商都会默认接受这一结果。在品牌优势较高的情况下,回收商和品牌制造商有动机达成再制造协议,实现双方的共赢,但品牌零售商会极力反对这一协议。此外,合作再制造模式并不一定能带来更高的消费者剩余,在一定条件下,翻新竞争模式下消费者剩余可能会超过合作再制造模式下的水平。

不对等权力结构下竞争性闭环供应链的回收模式选择均衡

针对两条具有不对等权力的竞争性闭环供应链,其中双链制造商均可选择己方回收(M模式)、委托零售商回收(R模式)或第三方回收(T模式)的3种模式之一,首先建立和求解博弈模型得到9种可能回收组合下的均衡解、成员利润和链利润,然后基于不同组合的比较推导双链回收模式选择的均衡策略,最后分析均衡组合的Pareto效率。结论表明:①主从链博弈存在“后动优势”现象,特别当从链回收者的回收效率不劣于主链时,从链的各项运营指标完全优于主链;②当从链回收模式任意给定时,无论双链竞争强度如何,主链制造商选择R模式对己方、零售商和整条链最有利;当主链回收模式给定时,随着竞争加剧,M模式、R模式和T模式将依次成为从链制造商和整条从链的最优选择;③RR、RM和RT三种组合均可能是双链的回收模式选择均衡,但在某些条件下RR和RM会陷入低效的囚徒困境。

差额碳税视角下应急产品闭环供应链的协调机制研究

为提高应急产品的资源利用效率并强化应急体系协同绿色发展,构造制造商处主导地位、零售商处从属地位的应急产品闭环供应链博弈模型。从差额碳税视角出发对比分析集中决策和分散决策下应急产品闭环供应链的各个均衡决策,推导出利用“讨价还价”模型实现供应链协调的条件,并进行算例分析。研究结果表明:差额碳税政策可以提高再制造应急产品的市场占比份额,促进资源的高效循环发展;讨价还价模型可以实现闭环供应链的有效协调。研究结果可为应对突发事件提供理论参考。

政府补贴和碳税对服装闭环供应链的影响

在全球碳减排共识之下,探索服装产业绿色低碳发展之路极具价值。基于消费者对传统服装和再制造服装的需求差异,构建了由原材料供应商、制造商、零售商及回收商组成的4级服装闭环供应链模型,着重探究政府补贴政策和碳税策略对服装再制造产业发展的影响。研究表明:政府补贴政策能够降低再制造服装的零售价,提升再制造服装的需求量,并增加供应链成员的利润;政府碳税策略使再制造服装的零售价上涨,需求量增加,但降低了企业生产再制造服装的积极性;征税和补贴同时实施的复合策略有助于减缓企业及政府的财政压力。研究结论可为政府政策制定及服装企业生产决策提供参考。

基于信息不对称与风险规避的低碳闭环供应链定价决策研究

为确定闭环供应链的产品定价和碳减排率,同时考虑制造商的风险规避行为和零售回收运营成本信息的不对称性,构建以制造商为主导的Stackelberg博弈模型,分析对比信息对称和信息不对称两种情况下的最优决策,利用数值分析验证结论。研究表明:产品的销售价格、批发价格、碳减排率及制造商效用都将随着制造商风险规避程度的提高而降低,而市场需求与零售商效用将增加;当零售商谎报回收运营成本时,相较于坦白回收运营成本,产品转移价格与零售商效用均有所提升,产品回收价格、废旧产品回收量和制造商效用则降低,且风险规避和信息不对称均对碳减排产生消极影响。