通用化对雷达备件供应保障的影响分析

通过建立和分析备件供应保障的量化指标,推导出通用化对备件保障度和备件购置费用影响的关系式,并给出了应用实例,为部队备件供应保障决策提供了理论依据。     

单板纳星电源系统能量平衡仿真

能量平衡是微纳卫星电源系统设计和考核的重要要求,在地面通常通过数值仿真进行评价。介绍单板纳星电源系统结构和特点;分别对太阳电池阵、蓄电池组和卫星负载进行数学建模;结合卫星姿态动力学进行能量平衡仿真,仿真结果可以实时反映卫星的功率变化、电池容量和能量平衡情况。电源系统在轨试验数据与仿真结果基本一致,证明所建模型是正确的,仿真方法有效。     

Selling to strategic and loss‐averse consumers: Stocking,procurement, and product design policies

Motivated by the presence of loss‐averse decision making behavior in practice, this article considers a supply chain consisting of a firm and strategic consumers who possess an S‐shaped loss‐averse utility function. In the model, consumers decide the purchase timing and the firm chooses the inventory level. We find that the loss‐averse consumers' strategic purchasing behavior is determined by their perceived gain and loss from strategic purchase delay, and the given rationing risk. Thus, the firm that is cognizant of this property tailors its inventory stocking policy based on the consumers' loss‐averse behavior such as their perceived values of gain and loss, and their sensitivity to them. We also demonstrate that the firm's equilibrium inventory stocking policy reflects both the economic logic of the traditional newsvendor inventory model, and the loss‐averse behavior of consumers. The equilibrium order quantity is significantly different from those derived from models that assume that the consumers are risk neutral and homogeneous in their valuations. We show that the firm that ignores strategic consumer's loss‐aversion behavior tends to keep an unnecessarily high inventory level that leads to excessive leftovers. Our numerical experiments further reveal that in some extreme cases the firm that ignores strategic consumer's loss‐aversion behavior generates almost 92% more leftovers than the firm that possesses consumers’ loss‐aversion information and takes it into account when making managerial decisions. To mitigate the consumer's forward‐looking behavior, we propose the adoption of the practice of agile supply chain management, which possesses the following attributes: (i) procuring inventory after observing real‐time demand information, (ii) enhanced design (which maintains the current production mix but improves the product performance to a higher level), and (iii) customized design (which maintains the current performance level but increases the variety of the current production line to meet consumers’ specific demands). We show that such a practice can induce the consumer to make early purchases by increasing their rationing risk, increasing the product value, or diversifying the product line. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 435–453, 2015     

Coping with shortages caused by disruptive events in automobile supply chains

Unpredictable disruptive events significantly increase the difficulty of the management of automobile supply chains. In this paper, we propose an automobile production planning problem with component chips substitution in a finite planning horizon. The shortage of one chip can be compensated by another chip of the same type with a higher-end feature at an additional cost. Therefore, the automobile manufacturer can divert the on-hand inventory of chips to product lines that are more profitable in the event of shortages caused by supply chain disruptions. To cope with this, we propose a max-min robust optimization model that captures the uncertain supplies of chips. We show that the robust model has a mixed-integer programming equivalence that can be solved by a commercial IP solver directly. We compare the max-min robust model with the corresponding deterministic and two-stage stochastic models for the same problem through extensive numerical experiments. The computational results show that the max-min robust model outperforms the other two models in terms of the average and worst-case profits.     

A location‐inventory model with lateral transshipments

We study an infinite horizon periodic stochastic inventory system consisting of retail outlets and customers located on a homogenous line segment. In each period, the total demand, generated by the customers on the line, is normally distributed. To better match supply and demand, we incorporate lateral transshipments. We propose a compact model in which the strategic decisions—the number and locations of retail outlets—are determined simultaneously with the operational decisions—the inventory replenishment and transshipment quantities. We find the optimal balance between the risk‐pooling considerations, which drive down the optimal number of retail outlets, and lateral transshipments, which drive up the optimal number of retail outlets. We also explore the sensitivity of the optimal number of retail outlets to various problem parameters. This article presents a novel way of integrating lateral transshipments in the context of an inventory‐location model. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

More Attacks,Less Violence

A response to John Stone, Dale Peterson, and Gary McGraw on cyber war.     

China's Naval Ambitions in the Indian Ocean

This article argues that an increasingly sea-power-minded China will neither shelter passively in coastal waters, nor throw itself into competition with the United States in the Pacific Ocean. Rather, Beijing will direct its energies toward South and Southeast Asia, where supplies of oil, natural gas, and other commodities critical to China's economic development must pass. There China will encounter an equally sea-power-minded India that enjoys marked geostrategic advantages. Beijing will likely content itself with ‘soft power’ diplomacy in these regions until it can settle the dispute with Taiwan, freeing up resources for maritime endeavors farther from China's coasts.     

Specification vagueness and supply quality risk

Specifying quality requirement is integral to any sourcing relationship, but vague and ambiguous specifications can often be observed in practice, especially when a buyer is in the initial stage of sourcing a new product. In this research, we study a supplier's production incentives under vague or exact quality specifications. We prove that a vague specification may in fact motivate the supplier to increase its quantity provision, resulting in a higher delivery quality. Vague quality specification can therefore be advantageous for a buyer to screen potential suppliers with an initial test order, and then rely on the received quality level to set more concrete quality guidelines. There is a degree, though, to which vague quality specification can be effective, as too much vagueness may decrease the supplier's quantity provision and hence the expected delivery quality. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

Impact of transfer pricing methods for tax purposes on supply chain performance under demand uncertainty

Transfer pricing refers to the pricing of an intermediate product or service within a firm. This product or service is transferred between two divisions of the firm. Thus, transfer pricing is closely related to the allocation of profits in a supply chain. Motivated by the significant impact of transfer pricing methods for tax purposes on operational decisions and the corresponding profits of a supply chain, in this article, we study a decentralized supply chain of a multinational firm consisting of two divisions: a manufacturing division and a retail division. These two divisions are located in different countries under demand uncertainty. The retail division orders an intermediate product from the upstream manufacturing division and sets the retail price under random customer demand. The manufacturing division accepts or rejects the retail division's order. We specifically consider two commonly used transfer pricing methods for tax purposes: the cost‐plus method and the resale‐price method. We compare the supply chain profits under these two methods. Based on the newsvendor framework, our analysis shows that the cost‐plus method tends to allocate a higher percentage of profit to the retail division, whereas the resale‐price method tends to achieve a higher firm‐wide profit. However, as the variability of demand increases, our numerical study suggests that the firm‐wide and divisional profits tend to be higher under the cost‐plus method than they are under the resale‐price method. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

高层建筑灭火救援供水方式实际应用分析

高层建筑火场供水问题是灭火救援能否取得成功的关键,对其供水方式进行研究具有重要意义和紧迫性.按“固、内、外”三个类别,从固定设施、移动装备、现场环境和人员等方面,就现有高层建筑常用供水方式的优缺点进行论述,并结合供水方式的优缺点,就供水车数量确定、水带铺设方式、移动供水装备选用、熟悉演练等方面提出建议,以期提高高层建筑供水水平.