含回路网络的中心选址 Ⅰ.单回路情形

本文对单回路网络引入了一种新的双标号准则,借此给出了求其1-中心的O(n)阶算法。对边不交的多回路网络,在Ⅱ中将给出一个有效的去边准则。设网络G=(V,E)是一个无向连通图,V(G)和E(E)分别表示其顶点集和边集。在此,我们考虑如下的网络选址问题其中p∈G表示p也可取在边上。关于树网络的中心选址,有关文献[3]、[4]、[5]已做了深入的研究。本文对单回路网络引进了双标号准则,从而给出此类网络1-中心选址的O(n)阶算法。     

"物流配送中心选址的随机数学模型"的有效性研究

从实际应用出发，对文献[1]中提出物流配送中心选址的随机数学模型进行了有效性分析。通过计算机模拟得到的数据，分别应用随机数学模型和传统选址方法对不同规模的配送网络进行选址，通过分析两者在不同条件下的总费用，得到了该随机模型的一些有趣的性质，为实际中的应用提供了依据。     

全要素生产率如何影响我国制造业企业的区位选址决策

新经济地理理论以及新近发展的“‘新’新经济地理理论”认为,高生产率企业通过集聚效应和选择效应存在于规模较大的市场,本文在后者理论框架下考察中国企业区位选址这一被忽视的问题。运用中国1999~2007年297个地级及以上城市100多万家企业的微观数据,采用倾向得分匹配方法克服样本选择性偏误,本文发现:相比低生产率企业组,高生产率企业选址于更大规模的城市。而且,这种选址倾向在不同区域和企业所有制上具有差异表现:相比传统中、西部地区,东部地区高生产率企业选址于大城市的倾向更为明显;相比集体企业,港澳台、外商及私营企业的这种倾向性更为显著,且估计结果显示国有企业选址不受全要素生产率水平的影响。以上发现为我国制造业企业区位选址决策的制定提供了新的思路。     

电动汽车充电站选址问题研究

研究了电动汽车作为通勤工具情况下的充电站选址问题.首先根据城市通勤道路长度、各条道路上的通勤人员拟使用电动汽车的数量,以及电动汽车的最大续航里程等信息,构建了包含两种边的赋权网络图,进一步将电动汽车充电站选址问题转化为赋权网络图的最大覆盖问题,并建立了以极大化满足用户需求为目标的充电站选址问题整数非线性规划模型,设计了求解模型的启发式算法.最后,通过一个具体算例对模型及算法进行了验证,结果显示,模型和算法是解决电动汽车充电站选址问题有效方法.     

一类应急服务设施选址问题的模型及算法

在分析城市应急服务设施选址问题基础上,建立了限定期条件下应急服务设施选址问题的数学模型,提出了一种基于遗传算法的应急服务设施选址模型的有效算法,并通过算例分析验证了该方法的有效性.     

“64号文”的应对之策

2010年8月11日,财政部、国家税务总局和商务部公开发布了财税[2010]64号文件（以下简称“64号文”）,对注册在服务外包示范城市（以下简称“示范城市”）的企业从事离岸服务外包业务取得的收入免征营业税。这是继2009年出台的国办函[2009]9号和财税[2009]63号文件对注册在示范城市的技术先进型服务企业给予营业税和所得税的优惠政策之后,     

三角形与三棱锥的一个向量性质的逆定理

文[1]、文[2]、文[3]及文[4]对一个三角形重心向量性质进行拓广，文[5]证明了文[1]的逆定理也成立，文[6]将以上的重心性质进行了再推广得到了两个定理，我们可以将这两个定理加强为以下两个命题，证明类似文[6]在此不再证明．     

三角形与三棱锥的一个向量性质的逆定理

文[1]、文[2]、文[3]及文[4]对一个三角形重心向量性质进行拓广,文[5]证明了文[1]的逆定理也成立,文[6]将以上的重心性质进行了再推广得到了两个定理,我们可以将这两个定理加强为以下两个命题,证明类似文[6]在此不再证明.命题1如图1所示,设P为△ABC所在平面上任意一点,λ1PA λ     

曲线拐点充分条件证明中的常见错误

文[1]给出了判别曲线拐点的两个充分条件,文[2]给出了一个充分条件,但三个定理的证明都是错误的.同时,文[1]的两个推论也是错误的.本文通过反例分析了其错因,并给出了文[1]中一个拐点充分条件的正确证明.     

影响城市地价最优因素组合的选择及权重确定

笔者在城市土地定级估价综合模型[1] 的基础上 ,应用最优回归自变量集的选择方法[2 ] ,得到了影响城市地价最优因素组合的选择方法及权重的确定方法 ,并将其实际应用于山西省古交市的地产评估 ,结果表明 ,该方法比现行方法节省经费且使评估结果更符合实际。     

考虑企业释放质量信号行为的产品推广策略

为吸引消费者, 一些企业尝试以释放质量信号为手段进行产品推广。本文考虑消费者购买时的参考效用, 通过构建模型, 探讨了短期经营下低质量企业不释放质量信号、短期经营下低质量企业释放质量信号、长期经营下低质量企业不释放质量信号和长期经营下低质量企业释放质量信号等四种情况下的产品定价策略, 并分析了释放质量信号对企业运营带来的利弊。研究发现:长期经营下低质量企业释放质量信号时, 产品质量差距的扩大将提高竞争企业的最优定价, 而释放质量信号程度的增加则将使最优定价降低。同时, 通过释放质量信号, 短期内低质量企业看似可以借此获得大量需求, 但现实中可行性不高。从长期经营来看, 以释放质量信号为手段的推广策略实际上会损害整个市场的利益。     

Stocking and quality decisions for deteriorating perishable products under competition

In this study, we address the joint inventory and quality management in a Cournot duopoly, for a seasonally produced, perishable product whose quality deteriorates over time. The sales of the product occur over two periods, namely the season (first period) and the off-season (second period). Apart from the stocking quantities for the two periods, firms must decide the quality levels of the units to stock for the second selling period. Firms incur a cost to maintain particular quality levels. The equilibrium policies of the firms are characterized, and we discuss the impact of the firms’ quality costs on their inventory and quality decisions. We identify the conditions of the quality costs when competition ceases to exist in the second period, and analyse the impact of the quality costs on inter-temporal price fluctuations and product availability. Using the unconstrained equilibrium policy, we frame the firms’ inventory disposal policies when production yields are exogenous.     

Equilibria and dynamics of supply chain network competition with information asymmetry in quality and minimum quality standards

In this paper, we construct a supply chain network model with information asymmetry in product quality. The competing, profit-maximizing firms with, possibly, multiple manufacturing plants, which may be located on-shore or off-shore, are aware of the quality of the product that they produce but consumers, at the demand markets, only know the average quality. Such a framework is relevant to products ranging from certain foods to pharmaceuticals. We propose both an equilibrium model and its dynamic counterpart and demonstrate how minimum quality standards can be incorporated. Qualitative results as well as an algorithm are presented, along with convergence results. The numerical examples, accompanied by sensitivity analysis, reveal interesting results and insights for firms, consumers, as well as policy-makers, who impose the minimum quality standards.     

Price and quality competition: The effect of differentiation and vertical integration

This paper studies an instance of price and quality competition between firms as seen in the recent Internet market. Consumers purchase a product based on not only its price but also its quality level; therefore, two firms compete in determining their prices and quality levels to maximize their profits. Characterizing this competition from a microeconomic viewpoint, we consider two possible business strategies that firms can utilize to overcome the competition—the differentiation and the vertical integration with another complementary firm. We show an interesting result not seen in the well-known Bertrand price competition: not only does the differentiation always increase the firms’ profits, but also it can increase the consumer’s welfare in a quality-sensitive market. We further derive that under some mild conditions the monopolistic vertical integration that excludes the combination-purchase with a competitor’s product is beneficial for both the integrated firm and its consumers.     

Impact of product pricing and timing of investment decisions on supply chain co-opetition

In supply chain co-opetition, firms simultaneously compete and co-operate in order to maximize their profits. We consider the nature of co-opetition between two firms: The product supplier invests in the technology to improve quality, and the purchasing firm (buyer) invests in selling effort to develop the market for the product before uncertainty in demand is resolved. We consider three different decision making structures and discuss the optimal configuration from each firm’s perspective. In case 1, the supplier invests in product quality and sets the wholesale price for the product. The buyer then exerts selling effort to develop the market and following demand potential realization, sets the resale price. In case 2, the supplier invests in product quality followed by the buyer’s investment in selling effort. Then, after demand potential is observed, the supplier sets the wholesale price and the buyer sets the resale price. Finally, in case 3, both firms simultaneously invest in product quality and selling effort, respectively. Subsequently, observing the demand potential, the supplier sets the wholesale price and the buyer sets the resale price. We compare all configuration options from both the perspective of the supplier and the buyer, and show that the level of investment by the firms depends on the nature of competition between them and the level of uncertainty in demand. Our analysis reveals that although configuration 1 results in the highest profits for the integrated channel, there is no clear dominating preference on system configuration from the perspective of both parties. The incentives of the co-opetition partners and the investment levels are mainly governed by the cost structure and the level of uncertainty in demand. We examine and discuss the relation between system parameters and the incentives in desiging the supply contract structure.     

Signaling advertising by multiproduct firms

We consider the use of advertising expenses as quality signals in multiproduct firms, extending previous results on single product firms. In our model, a firm introduces sequentially two products whose qualities are positively correlated. We investigate whether there exist information spillovers from the first to the second market. We show that, when correlation is high, the equilibrium in market 2 depends on the quality reputation the firm has gained in market 1. Moreover, if a firm with a high-quality product 1 wants to separate from its low-quality counterpart, it needs to advertise more in this market than if the qualities of the two products are unrelated. This advertising level signals not only high quality in the first market, but also the likely quality of the second product. Thus, advertising in the first market has information spillovers in the second market.     

贸易和产业政策对企业产品质量的影响博弈

在纵向产品差异化的双寡头竞争的框架下,对政府的贸易和产业政策做了分析,得到的主要结论为,只要国内企业生产低质量的产品,则贸易自由化会导致国内企业的产出水平下降和所有产品价格的提高;在贸易和产业政策一定的情况下,当国内企业的技术水平比较低时,国内企业生产低质量产品可以使社会福利达到最大化;另外,政府可以通过关税和补贴的干预使企业的产品质量产生跃进,超过国外竞争者.     

Designing a referral reward program in freemium: The role of network externalities

We develop a model to explore firms’ decisions on designing referral reward programs in freemium. We find two indices that firms could compare against value discrepancy to choose their strategy. The optimal price and referral reward rate are obtained. We find that the absence of network externality relating to product quality makes referral dysfunctional, and we conduct sensitivity analysis. This study contributes to theories that incorporate a referral reward program into the freemium model and provides practitioners with viable takeaways.     

Product concept and prototype flexibility in manufacturing: Implications for customer satisfaction

A rapidly changing competitive landscape and dynamic customer expectations require manufacturing firms to seek flexibility in product development. Product concept flexibility (i.e., developing design options) and product prototype flexibility (i.e., creating working models) emerge as effective ways to quickly develop new products that meet competitive challenges and satisfy customer demands. Product concept flexibility enables firms to fully explore various product definitions and ideas. Product prototype flexibility allows firms to gather customers’ feedback and investigate design feasibility. Using data from 273 manufacturing firms, this research tests mediating, moderating, and additive models that relate product concept flexibility, product prototype flexibility, and customer satisfaction. The results indicate that firms with high product concept flexibility are more likely to benefit from prototype flexibility than firms with low product concept flexibility, and that product concept flexibility and product prototype flexibility act independently and additively to predict customer satisfaction.     

A note on price and quality competition between asymmetric firms

This paper analyzes the impact of asymmetry between firms on the outcome of price and quality competition from a microeconomic viewpoint. Consumers purchase a product based on not only its price but also its quality level; therefore, two firms compete in determining their prices and quality levels to maximize their profits. The asymmetry arises from the difference in consumers’ loyalty to each firm; that asymmetry then determines a character of differentiation between firms. Our purpose is to show how asymmetry influences competition under varying consumers’ price- and quality-sensitivity. In doing so, we extend earlier work in the area of price and quality competition. We show that in both the moderately quality-sensitive and price-sensitive markets, higher consumers’ sensitivity as well as lower consumers’ loyalty to any firm leads to intense competition, resulting in a decrease of both firms’ equilibrium profits. On the other hand, in highly quality-sensitive market, asymmetry compels the smaller firm to change its competitive strategy. In general, this is more beneficial to the larger firm, as the smaller firm’s profit tends to decline. In the worst case, the smaller firm is driven out of business under equilibrium.