链与链基于价格和服务竞争的纵向结构选择

通过构建两个制造商、两个排他性零售构成的竞争供应链结构模型,揭示价格竞争、服务竞争以及服务行业的成本对供应链纵向控制结构选择绩效的影响,从而识别出高中低服务成本行业竞争供应链的纵向结构均衡差异特征．上述结论对进一步探索竞争供应链纵向结构协调的合同选择提供了基本的理论基础．     

供应商竞争关系下的第三方物流融资及物流服务决策

研究第三方物流企业（3PL）在处于竞争关系中的供应商面临资金约束时的融资策略选择问题。考虑由两个竞争关系的供应商和一个零售商构成的两级供应链,3PL企业为供应链提供代采购、物流及融资服务,分别考虑在代采购中向供应商提供融资能够获得价格折扣和代采购中考虑额外资金成本情况下,3PL融资意愿选择,向供应商提供（不提供）融资。建立3PL、供应商和零售商在不同情况下的收益模型,并给出供应商和零售商的最优定价,以及3PL的最优物流服务收费决策,通过比较融资前后各个企业的收益分析3PL参与供应链融资的积极作用。研究发现3PL向处于竞争环境下的资金短缺供应商提供融资能够增加3PL、零售商和供应链整体的收益,且3PL更愿意在考虑自身资金成本的情况下向供应商提供融资,并且供应商之间竞争越激烈,3PL和零售商的获益越大。     

Supply chain network design under oligopolistic price and service level competition with foresight

In this paper a new bi-level model for designing the network structure of a competitive supply chain (SC) is presented with anticipating variable prices and service levels competition in markets under stochastic price and service level dependent elastic demands with the presence of existing, external rivals. The network structure of the new entrant SC would be designed under the limited production capacity of its producers in a way to maximize its future capturable profit in the competitive markets. The network of the new SC is assumed to be set “once and for all” but further price and service level adjustments are possible. Outer part of this bi-level model deals with strategic decisions of SC network design. Given the SC network structure assigned by the outer model in each iteration, the inner equilibrium model determines the equilibrium retail prices and service levels. Finally, we illustrate the model through several numerical examples.     

一种面向Web服务的分级服务模型*

以服务响应时间为QoS参数,提出了一种面向Web服务的分级QoS方法,该方法从预测请求响应时间入手,通过区分操作类型并采用优先级队列调度策略,进而保证请求响应时间.在ONCE平台内置SOAP引擎SOAPExpress的基础上进行了原型实现.实验表明,该方法能有效地保证不同级别用户的请求响应时间,实现服务分级.     

Price and capacity competition of application services duopoly

In this paper, we study the price and capacity competition of two application service providers (ASPs). The customers realize an intrinsic time-independent value from transactions processed by the ASP. The cost to the customers includes both the price charged by the ASP and the delay cost due to turnaround time of the ASP service system. Customers will choose to join the ASP who delivers a higher net value of the service. This paper examines the competition between two ASPs and the impact of customers' delay cost on ASP's pricing and capacity decisions. We find that the ASP with higher capacity will charge a higher price and enjoy a larger market share and, surprisingly, that customers' delay cost has no direct impact on the arrival rates to the ASPs but affects the ASPs' pricing decisions. The ASPs will charge a higher price premium to capitalize customers' higher delay cost. For the long-run problem, we find that in the presence of higher customer's delay cost, both ASPs' optimal profits suffer, in contrast to the short-run problem where a higher customer's delay cost leads to a higher profitability for both ASPs.     

Price differentiation and control in the Kelly mechanism

The design and implementation of resource allocation and pricing for computing and network resources are crucial for system and user performance. Among various designing objectives, we target on maximizing the social welfare, i.e., the summation of all user utilities. The challenge comes from the fact that users are autonomous and their utilities are unknown to the system designer. Under the Kelly mechanism, users bid and proportionally share resources. When user population is large and “price-taking” can be assumed, the Kelly mechanism maximizes the social welfare; however, under oligopolistic competitions, this mechanism might induce an efficiency loss up to 25% of the welfare optimum.     

Price competition in duopoly supply chains with stochastic demand

In the literature, substantial researches have been carried out on supply chain coordination. The majority of these studies suggest a mechanism that enforces the supply chain members to follow the strategies that produce the equilibrium of an integrated supply chain. Moreover, most of researches do not consider the competition among supply chains.In this study, we consider an industry consisting of two distinct supply chains which compete with each other over price. Three algorithms are presented to calculate the equilibrium of three possible industry structures. It is assumed that demand is stochastic with additive form whose random component has a uniform distribution. Furthermore, the effect of competition and demand uncertainty intensity on the Nash equilibrium of the structures and supply chains’ profits are discussed in a numerical example.     

Price and leadtime competition,and coordination for make-to-order supply chains

This paper develops a game theoretic model of a one-manufacturer and one-retailer supply chain facing an outside integrated chain (manufacturer) to study the price and leadtime competition and investigate coordination of the supply chain, where the make-to-order production mode is employed and consumers are sensitive to retail price and leadtime. We find that decentralization of the supply chain increases its leadtime while decreases the rival’s leadtime; and the decentralization increases the retail prices. The existence of the outside competitor raises the leadtime. A higher reservation price or brand differentiation increases the retail prices but decreases the leadtimes; a higher transportation cost or lower leadtime sensitivity increases the retail prices and the leadtimes. The coordination of the supply chain facing integrated rival harms the integrated rival. We design contracts to coordinate the supply chain under leadtime-decision-first scenario and wholesale-price-decision-first scenario, respectively. Further, we find that the sequence of decisions affects the validity of the all-unit quantity discount scheme in coordinating the supply chain.     

Providing service differentiation in pure IP-based networks

The lack of an effective cooperation between the data, control and management plane of QoS routing solutions presented so far, prevents the implementation of service differentiation in the context of pure IP-based networks. Most of paths calculation proposals performed by the control plane are unaware of service characteristics of each flow. Scalable data plane QoS proposals ignore the issue about selecting the best paths to route the traffic. Proposed management plane schemes do not perform the network state maintenance and service level monitoring. Multi-service routing is a flow-based forwarding protocol that implements the service differentiation in pure IP-based networks, using a straight cooperation between data, control and management plane. This cooperation is accomplished by a data plane supporting the DiffServ model and performs route selection based on flows service class, which is exploited by the management plane to carry out the network state maintenance, and performance monitoring by using the RTCP protocol, to provide service metrics to control plane for route calculation. Simulation experiments show better performance results achieved by Multi-service routing compared to those obtained by traditional link state protocol with the DiffServ model and QoS routing in heavy loaded network scenarios of mixed traffic having different service requirements.     

基于优先级的服务区分和速率控制策略

针对中高速无线传感器网络中不同种类的网络流量对服务质量的需求,提出一种基于优先级的服务区分和速率控制策略。该策略对实时性和可靠性要求强的流量赋予高优先级以进行服务区分;并利用ε因子计算节点的速率差,逐跳地调整其上游节点的发送速率。仿真结果表明,所提出的策略能够保证高优先级实时流量具有高吞吐量和低延迟,并保持网络吞吐量的稳定。     

Developing and validating a physical product e-tailing systems success model

The study attempts to develop and validate a physical product e-tailing systems success model based on the existing information systems/e-commerce systems success models and consumer behavior literature. The proposed e-tailing success model describes the interrelationships among nine dimensions: Information Quality, System Quality, Service Quality, Product Quality, Perceived Price, Perceived Value, User Satisfaction, Intention to Reuse, and Electronic Word-of-Mouth. Data collected from 258 valid respondents are tested against the research model using the partial least squares approach. The results indicate that Information Quality, System Quality, Service Quality, Product Quality, and Perceived Price (i.e. e-tailers’ quality and price attributes) have a significant influence on both Perceived Value and User Satisfaction, and that Perceived Value significantly affects both Intention to Reuse and eWOM (i.e. customers’ loyalty) directly or indirectly through the mediation of User Satisfaction. The results of this study provide several important theoretical and practical implications for e-tailing systems success.     

Dynamic search engine competition with a knowledge-sharing service

This research investigates how an inferior search engine can impact its competition with a superior search engine by introducing a knowledge-sharing service. Specifically, we model the dynamic competition between an inferior search engine with a knowledge-sharing service and a pure superior search engine. We show that the degree to which the knowledge-sharing service helps the inferior search engine to enlarge its market share increases as the amount of online content decreases and the complexity of searchers' questions increases. We also find that the inferior search engine is generally advised to close its database of answers for more market share.     

Two-node market under imperfect competition

In this paper, we consider a Cournot auction with uniform nodal prices for a two-node market. The structure of each local market is an oligopoly. We demonstrate how the type of Nash equilibrium depends on the throughput. Finally, we investigate the optimum throughput problem under an imperfect competition in the market.     

Usage based service differentiation for end-to-end quality of service management

It is often difficult to ensure that every application in a computing environment receives the level of quality of service required by their users. In such cases, the demand for computing resources to do so simply exceeds the limited supply that is available. To ensure that at least some user applications meet quality of service requirements, service differentiation is one approach growing in popularity. In this approach, preferential service is given to selected applications, while others deemed less important suffer in comparison. Most work in this area bases service differentiation decisions on static information about the applications, such as the name and type of application, the owner of the application, execution time, and the host on which the application was executed. In this paper, we discuss a new approach to service differentiation that takes into consideration dynamic application usage information in service differentiation decisions. In doing so, we can make better or fairer service differentiation decisions that allow more users to enjoy higher levels of quality of service. This is accomplished by ensuring preferential service is given to applications whose users can actually benefit from the improved service, as opposed to those applications that are essentially ignored or in a state that renders them unusable.     

Unsupervised speaker recognition based on competition between self-organizing maps

We present a method for clustering the speakers from unlabeled and unsegmented conversation (with known number of speakers), when no a priori knowledge about the identity of the participants is given. Each speaker was modeled by a self-organizing map (SOM). The SOMs were randomly initiated. An iterative algorithm allows the data move from one model to another and adjust the SOMs. The restriction that the data can move only in small groups but not by moving each and every feature vector separately force the SOMs to adjust to speakers (instead of phonemes or other vocal events). This method was applied to high-quality conversations with two to five participants and to two-speaker telephone-quality conversations. The results for two (both high- and telephone-quality) and three speakers were over 80% correct segmentation. The problem becomes even harder when the number of participants is also unknown. Based on the iterative clustering algorithm a validity criterion was also developed to estimate the number of speakers. In 16 out of 17 conversations of high-quality conversations between two and three participants, the estimation of the number of the participants was correct. In telephone-quality the results were poorer.     

竞争环境下B2C平台增值服务投资决策

为提高竞争环境下的平台经济效益,讨论平台企业对双边用户的增值服务投资问题,在考虑用户多归属条件下构建B2C平台竞争模型.通过比较分析发现,在双边单归属或一边多归属条件下,平台企业的最优投资满足一个区间策略:若投资资源小于该区间的下界,则根据边际投资成本小于或大于某一阈值,平台企业选择投资全部或部分资源;若投资资源大于该区间的上界,则最优投资存在两个纯策略均衡;若投资资源位于该区间内,则最优投资存在唯一纳什均衡.此外,在双边多归属条件下,平台企业的最优投资满足一个单阈值策略:根据边际投资成本小于或大于某一阈值,平台企业选择投资全部或部分资源.     

Airline flight schedule planning under competition

This paper presents a modeling framework for airline flight schedule planning under competition. The framework generates an operational flight timetable that maximizes the airline's revenue, while ensuring efficient utilization of the airline's resources (e.g. aircraft and crew). It explicitly considers passenger demand shift due to the network-level competition with other airlines. It also considers minimizing the needless ground time of the resources. The problem is formulated in the form of a bi-level mathematical program where the upper level represents the airline scheduling decisions, while the lower level captures passenger responses in terms of itinerary choices. A solution methodology is developed which integrates a meta- heuristic search algorithm, a network competition analysis model, and a resource (e.g. aircraft and crew) tracking model. The performance of the framework is evaluated through several experiments to develop the schedule for a major U.S. airline. The results demonstrate the success of the framework to develop a competitive schedule with efficient resources.     

Self-organized service orchestration through collective differentiation.

This paper shows how self-(*) mechanisms give rise to complex but predictable and therefore steerable global system behavior in a cooperative computing environment. The operation of and the interactions between a set of networked autonomic devices are simulated. These are used as access points to a number of services, have the ability to accept or delegate execution of the associated tasks, and can adjust their internal state in response to the demand. At initialization, all devices are assigned a random internal state, i.e., there is no correlation between their configuration and the tasks that they are expected to perform. The authors study the emergence of cooperation and find that it spontaneously occurs when specific conditions are met, which allow individual devices to focus on performing a single task, sacrificing their ability to efficiently perform others. A relatively simple model that can be completely and thoroughly analyzed was chosen so as to demonstrate how the methodology developed to study complex adaptive systems in biology can be a powerful tool when planning the deployment of large ensembles of interacting autonomic devices.