Ho-fung Leung

On agent-mediated electronic commerce

This paper surveys and analyzes the state of the art of agent-mediated electronic commerce (e-commerce), concentrating particularly on the business-to-consumer (B2C) and business-to-business (B2B) aspects. From the consumer buying behavior perspective, agents are being used in the following activities: need identification, product brokering, buyer coalition formation, merchant brokering, and negotiation. The roles of agents in B2B e-commerce are discussed through the business-to-business transaction model that identifies agents as being employed in partnership formation, brokering, and negotiation. Having identified the roles for agents in B2C and B2B e-commerce, some of the key underpinning technologies of this vision are highlighted. Finally, we conclude by discussing the future directions and potential impediments to the wide-scale adoption of agent-mediated e-commerce.

A fuzzy constraint based model for bilateral, multi-issue negotiations in semi-competitive environments

This paper develops a fuzzy constraint based model for bilateral multi-issue negotiation in trading environments. In particular, we are concerned with the principled negotiation approach in which agents seek to strike a fair deal for both parties, but which, nevertheless, maximises their own payoff. Thus, there are elements of both competition and cooperation in the negotiation (hence semi-competitive environments). One of the key intuitions of the approach is that there is often more than one option that can satisfy the interests of both parties. So, if the opponent cannot accept an offer then the proponent should endeavour to find an alternative that is equally acceptable to it, but more acceptable to the opponent. That is, the agent should make a trade-off. Only if such a trade-off is not possible should the agent make a concession. Against this background, our model ensures the agents reach a deal that is fair (Pareto-optimal) for both parties if such a solution exists. Moreover, this is achieved by minimising the amount of private information that is revealed. The model uses prioritised fuzzy constraints to represent trade-offs between the different possible values of the negotiation issues and to indicate how concessions should be made when they are necessary. Also by using constraints to express negotiation proposals, the model can cover the negotiation space more efficiently since each exchange covers a region rather than a single point (which is what most existing models deal with). In addition, by incorporating the notion of a reward into our negotiation model, the agents can sometimes reach agreements that would not otherwise be possible.

A fuzzy-logic based bidding strategy for autonomous agents in continuous double auctions

Increasingly, many systems are being conceptualized, designed, and implemented as marketplaces in which autonomous software entities (agents) trade services. These services can be commodities in e-commerce applications or data and knowledge services in information economies. In many of these cases, there are both multiple agents that are looking to procure services and multiple agents that are looking to sell services at any one time. Such marketplaces are termed continuous double auctions (CDAs). Against this background, this paper develops new algorithms that buyer and seller agents can use to participate in CDAs. These algorithms employ heuristic fuzzy rules and fuzzy reasoning mechanisms in order to determine the best bid to make given the state of the marketplace. Moreover, we show how an agent can dynamically adjust its bidding behavior to respond effectively to changes in the supply and demand in the marketplace. We then show, by empirical evaluations, how our agents outperform four of the most prominent algorithms previously developed for CDAs (several of which have been shown to outperform human bidders in experimental studies).

Prioritised fuzzy constraint satisfaction problems: axioms, instantiation and validation

This paper identifies a generic axiom framework for prioritised fuzzy constraint satisfaction problems (PFCSPs), and proposes methods to instantiate it (i.e., to construct specific schemes which obey the generic axiom framework). In particular, we give five methods to construct the priority operators that are used for calculating the local satisfaction degree of a prioritised fuzzy constraint, and identify priority T-norm operators that can be used for calculating the global satisfaction degree of a prioritised fuzzy constraint problem. Moreover, a number of numerical examples and real examples are used to validate our system, and thus we further obtain some insights into our system. In addition, we explore the relationship between weight schemes and prioritised FCSP schemes, and reveal that the weighted FCSP schemes are the dual of prioritised FCSP schemes, which can, correspondingly, be called posterioritised FCSP schemes.

Towards ubiquitous tourist service coordination and process integration: A collaborative travel agent system architecture with semantic web services

With the recent advances in Internet and mobile technologies, there are increasing demands for ubiquitous access to tourist information systems for service coordination and process integration. However, due to disparate tourist information and service resources such as airlines, hotels, tour operators, it is still difficult for tourists to use them effectively during their trips or even in the planning stage. Neither can current tourist portals assist tourists proactively. To overcome this problem, we propose a Collaborative Travel Agent System (CTAS) based on a scalable, flexible, and intelligent Multi-Agent Information System (MAIS) architecture for proactive aids to Internet and mobile users. We also employ Semantic Web technologies for effective organization of information resources and service processes. We formulate our MAIS architecture for CTAS further with agent clusters based on a case study of a large service-oriented travel agency. Agent clusters may comprise several types of agents to achieve the goals involved in the major processes of a tourist’s trip. We show how agents can make use of ontology from the Semantic Web to help tourists better plan, understand, and specify their requirements collaboratively with the CTAS. We further illustrate how this can be successfully implemented with Web service technologies to integrate disparate Internet tourist resources. To conclude, we discuss and evaluate our approach from different stakeholders’ perspectives.

A Constraint-Based Interactive Train Rescheduling Tool

In this paper, we report the design and implementation of a constraint-based interactive train rescheduling tool, a project in collaboration with the International Institute for Software Technology, United Nations University (UNU/IIST), Macau. We formulate train rescheduling as constraint satisfaction and describe a constraint propagation approach for tackling the problem. Algorithms for timetable verification and train rescheduling are designed under a coherent framework. Formal correctness properties of the rescheduling algorithm are established. We define two optimality criteria for rescheduling that correspond to minimizing the number of station visits affected and passenger delay respectively. Two heuristics are then proposed to speed up and direct the search towards optimal solutions. The feasibility of our proposed algorithms and heuristics are confirmed with experimentation using real-life data.

Agents in E-commerce: state of the art

Abstract. This paper surveys the state of the art of agent-mediated electronic commerce (e-commerce), especially in business-to-consumer (B2C) e-commerce and business-to-business (B2B) e-commerce. From the consumer buying behaviour perspective, the roles of agents in B2C e-commerce are: product brokering, merchant brokering, and negotiation. The applications of agents in B2B e-commerce are mainly in supply chain management. Mobile agents, evolutionary agents, and data-mining agents are some special techniques which can be applied in agent-mediated e-commerce. In addition, some technologies for implementation are briefly reviewed. Finally, we conclude this paper by discussions on the future directions of agent-mediated e-commerce.

A Multi-Modal Agent Based Mobile Route Advisory System for Public Transport Network

In a metropolis such as Hong Kong, the transport network is massive, dynamic, and complicated, and therefore route finding is not an easy task, especially when routes comprising several modes of transport vehicles (such as bus, train, and ferry). This problem is even more important for e-tourism tourists and moving workforces, who may need to visit an unfamiliar part of the metropolis. To find a route that is the most cost-effective is even harder and time-consuming. In this paper, we present a conceptual model for a multi-modal public transport network and a multi-agent information system (MAIS) implementation architecture. We propose several intelligent approaches in the search agents to enhance the performance of route finding, in particular a knowledge-basket approach. Backend information agents gather updates periodically from transportation companies. We also consider hired transportation services, such as taxis and vans, which might offer similar costs for group commuters. We further support an agent-based auction sub-system for reservation of these mobile vehicles. We have built a route advisory system prototype with such features. Our system supports a flexible multiple user interface views on different mobile platforms. Our paper also includes some benchmark results to demonstrate the effectiveness our approach.

Ontology with likeliness and typicality of objects in concepts

Ontologies play an indispensable role in the Semantic Web by specifying the definitions of concepts and individual objects. However, most of the existing methods for constructing ontologies can only specify concepts as crisp sets. However, we cannot avoid encountering concepts that are without clear boundaries, or even vague in meanings. Therefore, existing ontology models are unable to cope with many real cases effectively. With respect to a certain category, certain objects are considered as more representative or typical. Cognitive psychologists explain this by the prototype theory of concepts. This notion should also be taken into account to improve conceptual modeling. While there has been different research attempting to handle vague concepts with fuzzy set theory, formal methods for measuring typicality of objects are still insufficient. We propose a cognitive model of concepts for ontologies, which handles both likeliness (fuzzy membership grade) and typicality of individuals. We also discuss the nature and differences between likeliness and typicality. This model not only enhances the effectiveness of conceptual modeling, but also brings the results of reasoning closer to human thinking. We believe that this research is beneficial to future research on ontological engineering in the Semantic Web.

A three-tier view-based methodology for M-services adaptation

With recent advances in mobile technologies and infrastructures, there are increasing demands for ubiquitous access to networked services. These services, generally known as m-services, extend supports from Web browsers on personal computers to handheld devices, such as mobile phones and PDAs. However, in general, the capabilities and bandwidth of these devices are significantly inferior to desktop computers over wired connections, which have been assumed by most Internet services. Instead of redesigning or adapting m-services in an ad-hoc manner for multiple platforms available in handheld devices, we propose a methodology for such adaptation based on three tiers: user interface views, data views, and process views. These views provide customization and help balance security and trust. User interface views provide alternative presentations of inputs and outputs. Data views summarize data over limited bandwidth and map heterogeneous data sources. In addition, we introduce a novel approach of applying process views to m-service adaptation, where mobile users may execute a more concise version or modified procedures of the original process. The process view also serves as the key mechanism for integrating user interface views and data views. In addition, we present a formal model on view consistency and integrity in our methodology. We demonstrate the feasibility of our methodology by extending a service negotiation subsystem into an m-service with multi-platform support.