• Research



Peer-to-Peer Networks

1. "On the scale of Peer-to-Peer Networks", Proceedings of the 13th Annual Workshop On Information Technologies and Systems (WITS'03), pp 13-18, December 2003, Seattle, USA (with Yong Tan and Yong-Pin Zhou)
In this paper, we study both the positive and negative scale effects on content sharing Peer-to-Peer (P2P) networks. Using analytical models and simulation, we evaluate the content distribution, content request, transmission cost and processing cost to investigate the characteristics of a P2P network. Our results show that increasing network scale has a positive effect on the expected content availability and the expected transmission cost, but a negative effect on the expected processing and search costs. All these costs can be balanced, and thus applied to determine the network size that optimizes overall the utility of a content sharing P2P community. We also investigate the impact of various P2P network parameters such as content distribution properties and request frequency.
2. "On the formation of Peer-to-Peer Networks: Self-Organized Sharing, Groups and Links ", Proceedings of  the 25th Annual International Conference on Information Systems (ICIS’04), Washington D.C., 2004 ( with Yong Tan and Prabuddha De)
In this paper, we investigate the formation of Peer-to-Peer (P2P) networks with rational participating agents (active peers). In the absence of a central planner, peers choose their own utility-maximizing strategies for coalition and peer formation. P2P networks evolve dynamically through the activities of interactions among individual nodes and group units. We propose a framework for multi-level formation dynamics, including an individual level (content sharing decision and group selection) and a group level (membership admission). The respective utilities of the individual node and the collective player are formulated as functions of operational performance metrics such as expected content availability, search delay, transmission delay, and download delay. We study the impacts of various system parameters on the emergence of self-organized P2P network configuration features such as free-riding level and group size. Furthermore, we investigate the stability and efficiency of P2P networks and propose internal transfer mechanisms that force stable networks to become efficient.


3. "Pricing Peer-to-Peer Networks :Content Provision and Search Intermediary", Proceedings of the 14th Annual Workshop On Information Technologies and Systems (WITS'04), December 2004, Washington D.C., USA  (with Yong Tan and Prabuddha De)
In this paper, we study the pricing schemes for services, such as content search and sharing, in Peer-to-Peer (P2P) networks. Using queueing and game-theoretic models, we evaluate the quality of service (QoS) metrics, including content availability, sharing cost, and overall search and download delays, in order to investigate the operational and economic efficiency of P2P networks. Consistent with usual implications of public goods provision, our model shows that, in the absence of appropriate incentive mechanisms, P2P users tend to over-request and under-provide contents. To regain the inherent efficiency loss due to decentralized decisions, we propose a pricing scheme that charges request fees for search intermediary service and compensates content provision so as to induce socially optimal content request and provision decisions by individuals. The content request fee increases with the network size. However, provision compensation increases (decreases) with the network size when the network is small (large). In addition, we also investigate the pricing scheme from the perspective of a monopolistic profit-seeking P2P provider, where, P2P participants are charged a higher price and the content provision compensation could be negative.  

Electronic Commerce

4. "Optimal Pricing and Advertising Policies for Web Services", Proceedings of the 14th Annual Workshop On Information Technologies and Systems (WITS'04), December 2004, Washington D.C., USA (with  Subodha Kumar and Suresh Sethi)
The accumulated evidence indicates that pure revenue models, such as free-access models (where the revenue is solely dependent on advertisements) or pure subscription fee based models (where the revenue is solely based on subscription fees, and advertisements are not shown to customers), are not sufficient to support the survival of online information sellers. Hence, hybrid models based on a combination of subscription fees and advertising revenues have replaced the pure revenue models on many web sites including the popular online content provider sites such as Wall Street Journal and Classmates Inc. In response to increasing interest in hybrid models, we study the problem of dynamic pricing of web content on a site where revenue is generated from subscription fee as well as advertisements. Using the optimal control theory, we obtain a dynamic pricing strategy of subscription and the optimal level of advertisements shown to the subscribers. Since the decision in any one time period affects the decisions of all subsequent time periods, the proposed dynamic model provides a globally optimal solution. Our model shows that the subscription fee is reduced initially to attract more customers, and is subsequently increased once a large customer base is obtained. Even when the fee increases in later periods, the number of subscribers increases due to the value associated with the quality of the content. We present several analytical and numerical results which provide some important managerial implications.
5. "Pricing Strategy Analysis for Collective Purchasing E-Commerce",  Proceedings of the 5th Annual Workshop On e-Business (WeB'06), December 2006, Milwaukee, USA (with Ting-Kai Hwang and Ping-Wen Chen)
Collective purchasing is becoming an increasingly popular marketing strategy of online retailers, as electronic marketplace provides a convenient channel for retailers to collect customers physically dispersed worldwide. Participating in collective purchasing, customers can enjoy purchasing with a better price. Online retailers also benefit from the reduction of operational cost by selling a large bundle size of products. However, the customers face a disutility cost from uncertainty and delay during the formation of a collective purchasing group. In this paper, we develop a simple economic model to examine the profitability and social efficiency of collective purchasing strategies under monopolistic and duopolistic market structures.
6. "Pricing Web Advertisement: Display Ads  V.S. Contextual Ads", Proceedings of the 11th Pacific Asia Conference on Information Systems (PACIS'07), July 2007, Auckland, New  Zealand (with Jhih-Hua Jhang-Li)

Most web sites provide display advertising and contextual advertising services simultaneously, which are the main ad formats in Internet. With multimedia format, the pricing of display ads is generally based on the occurrence of ad impressions. However, targeting their customers more accurately, contextual ads are performance based advertisements and are charged only if one visitor clicks a client’s appointed ad. In this paper, we develop an economic model to examine the pricing strategy, profitability, and social efficiency of these two heterogeneous web advertising channels, with respect to different market structures.

7. "Efficiency Analysis for Display Ads and Contextual Search",  Proceedings of the 9th  International Conference of Electronic Commerce (ICEC'07), August 2007, Minneapolis, USA (with Jhih-Hua Jhang-Li)
Most News Web sites provide display ads and contextual ads, which are the main ad formats in Internet. Unlike display ads, contextual ad is a performance based advertisement and allows clients to bid for their exposure rate. Not only do Web sites save operation costs but also clients plan their budget flexibly. However, in addition to accuracy of search results, contextual ads like a common resource pool will spend much more time to take the same number of clicks as display ads do.  In this paper, we develop a simple economic model to examine the profitability and social efficiency of contextual ads under monopolistic and duopolistic market structures.

Knowledge Management

8. "Efficient Knowledge Sharing: Performances and Incentives", Proceedings of the 18th Annual International conference of Information Resource Management Association  (IRMA'07), May 2007, Vancouver, CANADA (with Yung-ShaoYeh)

In this paper, we address the performance issue of Peer-to-Peer (P2P) knowledge sharing community based on two indices: the knowledge variety and the knowledge transfer. For each performance index, we examine Nash equilibrium and social equilibrium of knowledge contribution. While under-provision of knowledge contribution is a common phenomenon, the equilibrium results drawn from each criterion are significantly dissimilar. Results reveal the condition for the social optimality to sustain. Thus, in order to enhance performance of knowledge sharing, incentive mechanisms are presented to realizing an efficient knowledge sharing community.

9. "Knowledge Integration: A public goods approach under asymmetric information", Proceedings of the 18th Annual International conference of Information Resource Management Association  (IRMA'07), May 2007, Vancouver, CANADA ( with Jhih-Hua Jhang-Li)

Knowledge integration is one of the keys to e-business which has more competitive advantage than traditional organizations. However, building knowledge management system from technology-oriented and user viewpoint is insufficient. Because of the effect of free-riding, the benefit of knowledge integration can’t be linked to group size in direct proportion. This paper examines how the total effective level of effort persons exert vary with individual belief about knowledge level, group size, and their cost-knowledge level ratios. This study discusses the relation among these factors and proposes solutions to vanish the effect of free-riding under asymmetric information.

Digital Content Supply Chains

10. "Pricing Heterogeneous Content Distribution Channel: Efficiency and Profitability", Proceedings of the 5th Annual Workshop On e-Business (WeB'06), December 2006, Milwaukee, USA  

 The paper considers the pricing and allocation issues of distributing digital contents via dedicated websites (Web channel) and peer-to-peer networks (P2P channel). We examine the allocation equilibrium between these two channels, and present an incentive scheme to achieve an efficient channel configuration for an organization. We further analyze these two distribution channels in a competitive market. A business environment with asymmetric decision information will push the price and profit of both channels higher. Particularly, the second mover enjoys both higher price and market share. When both channels are integrated, the price of Web channel will be lower than P2P channel’s price, on the contrary to socially optimal pricing scheme. Consequently, the demand of P2P channel shrinks, and more customers experience worse service quality from Web channel.

11. "Optimal Contract of P2P Content Distribution", Proceedings of the 5th Annual Workshop On e-Business (WeB'06), December 2006, Milwaukee, USA 

A Peer-to-Peer (P2P) network becomes an increasingly popular content distribution channel. Utilizing the principal-agent model from incentive theory, this paper provides a contract model for a business P2P file sharing networks, in which contracted P2P participants compete for the provision service compensation. Optimal compensation scheme and corresponding capacity effort is presented. It is shown that monopolistic service compensation increases with the dispersion of peer positions and file size, but decreases with the network size and the content availability.

12. "Pricing Digital Content with DRM Mechanism", Proceedings of the 9th  International Conference of Electronic Commerce (ICEC'07), August 2007, Minneapolis, USA  (with Chia-Hao Lin)

As the development of digital device technology, almost all the kinds of information can be stored in digital format.  At the same time, the Internet and file sharing technology (such as P2P network) significantly alleviate the content distribution cost. However, better digital content distribution also means that people can acquire any digital contents easier without purchasing the digital rights.  Consequently, digital content providers utilize DRM (Digital Right Management) technology to inhibit the diffusion of pirating.  However, the adoption of DRM protection also reduces the flexibility of the digital content and results in value declination.
In this paper, we proposed an analytical model to examine the optimal DRM protection and pricing strategies of digital content.  We showed that the structure of the digital content industry (the relationship between content and platform providers) and content quality play important roles in the development of these strategies.  DRM protection level decreases as the content provider and platform provider are integrated.  As a result, more pirating activities occur.  While losing revenue from selling content, the merged company recovers this loss and gains from selling platform at a higher price.  Higher content quality will always strengthen the adoption of DRM when content and platform providers are operated independently.  However, if both providers are integrated, higher content quality may increase or decline DRM protection level.  In addition, we observed that providing content with higher quality will increase (decline) both the sales of legal content and corresponding revenue when content quality is sufficiently high (low).

13. "Pricing Web 2.0 Related Service: Peer Production", Proceedings of the 9th  International Conference of Electronic Commerce (ICEC'07), August 2007, Minneapolis, USA  (with Yi-Lin Lee)

Peer production has played an important role in the economics of Web 2.0 related services. User participation and contribution become the main driving dynamics of this new economic paradigm, significantly different from traditional firm-based or market-based production. However, the quality of peer production based service is uncertain, and highly related to not only the level of individual contribution but also the network externality of these contributions. To address and resolve this issue, in this paper, we propose an analytical model, based on the concepts of peer contribution and quality warranty, to study the pricing strategy of the increasingly emerging Web 2.0 related services. Best quality strategy under monopolistic market is found in our research. And under duopolistic market, one of the providers may provide higher quality than he advertises is also an important finding. Several implications have been discussed to help clarify the progress of peer production, and hints for peer production service providers are also presented.

Business Intelligence

14. "A Fuzzy Rule-based Bargaining Model for Online Group Purchasing",Proceedings of the  5th International Conference on Computational Intelligence in Economics and Finance (CIEF 2006), October, 2006,Kaohsiung City, Taiwan (with Ping-Wen Chen and Ting-Kai Hwang)

Online group purchasing or collective purchasing is the activity in which people who desire to buy the same merchandises join together so that they can negotiate with sellers for a better price through Internet. This paper utilizes fuzzy logic to develop a bargaining model for such activities. The model supports buyers to make group decision to set up their bargaining strategy; instead of using static rules, buyers can customize their fuzzy rule base that can infer to produce negotiation proposals to bargain with sellers. Experimental results show that (1) the prototype system with the fuzzy function is easy to use; (2) people enjoy online bargaining for better prices; (3) they think that online bargaining is very important and inevitable for electronic markets in the future.

15. "A One-to-Many Dynamic Negotiation Strategy Model Based on Fuzzy Theory", Proceedings of the  6th International Conference on Computational Intelligence in Economics and Finance (CIEF 2007), July, 2007 Salt Lake City, USA (with Ping-Wen Chen and Ting-Kai Hwang)

In recent years, the trend of online purchase is arising.  So far, most of the online purchasing use posted prices.  Therefore, buyers are usually in a passive and disadvantageous situation.  In this paper, we develop a one-to-many negotiation strategy model, based on multi-attribute utility theory, for buyers to negotiate with sellers.  Negotiation needs concession to succeed.  However, usually concession strategies are set up at the beginning of negotiation and fixed during the negotiation; the responses and behavior of opponents are not considered in the negotiation.  To conquer this problem, we use fuzzy theory and utility evaluation to integrate the information from sellers and conduct inferences, in order to dynamically adjust the concession.  In this way, we can enhance the negotiation ability of software agents to simulate the real-world human negotiation, so that agents will be able to explore more and better benefits for buyers.