[Show abstract][Hide abstract] ABSTRACT: This paper presents a formalization of the Web Service composition problem as a search problem in an AND/OR graph, and a search algorithm for searching the graph to identify composite service(s) that satisfies a Web Service request. Given a service request that can only be satisfied by a composition of Web Services, we identify the service categories that are relevant to the request and dynamically construct an AND/OR graph to capture the input/output dependencies among the Web Services of these service categories. The graph is modified, based on the information provided in the service request. The search algorithm is then used to search the modified AND/OR graph for a minimal and complete composite service template that satisfies the service request. The algorithm can be applied repeatedly to the graph to search for alternative templates until the result is approved by the service requester. We have evaluated the algorithm both analytically and experimentally, and the experiment results are presented. [PUBLICATION ABSTRACT]
Full-text · Article · Jan 2005 · International Journal of Web Services Research
[Show abstract][Hide abstract] ABSTRACT: This chapter presents the design and implementation of an Event-Trigger-Rule-based electronic supply-chain management system
(ESCM). The ESCM is constructed by a network of Knowledge Web Servers, each of which consists of a Web server, an Event Manager,
an Event-Trigger-Rule (ETR) Server, a Knowledge Profile Manager, a Persistent Object Manager, a Metadata Manager, a Negotiation
Server, and a Cost-Benefit Evaluation Server. Together, they manage the activities and interactions among Manufacturers, Distributors
and Retailers. ESCM offers a number of features. First and foremost is the flexibility offered to business entities in defining
their own rules according to their own business strategies. Second, since the rules that control the business activities are
installed and processed by the multiple copies of the ETR server installed at business entities' individual sites, their privacy
and security are safeguarded. Third, ESCM's event, event filtering and event notification mechanisms keep both Buyers and
Suppliers better informed with more timely information about business events so that they or their software systems can take
the proper actions in different business processes.
[Show abstract][Hide abstract] ABSTRACT: In this work, distributed and sharable learning resources are modeled by two types of Learning Objects (LOs): Atomic Learning
Object and Composite Learning Object. LOs are uniformly published as Web-services in a constraint-based Web-service registry
and are made sharable and reusable. This paper presents the learning object models for the specification of these two types
of LOs and an extended Web- service infrastructure, which provides a standard framework for the registration, discovery, binding
and invocation of these objects. An Event-Trigger-Rule Server is integrated with a Learning Process Execution Engine to make
Composite Learning Objects active, flexible, customizable and adaptive.
[Show abstract][Hide abstract] ABSTRACT: The ongoing explosion of web information calls for more intelligent and personalied methods towards better search result quality for advanced queries. Query log and click streams obtained from web browsers or search engines can contribute to better quality by exploiting the collaborative recommendations that are implicitly embedded in this information. This paper presents a new method that incorporates the notion of query nodes into PageRank model and integrates the implicite relevance feedback given by click streams into the automated process of authority analysis. This approach generalizes the well-known random-surfer model into a random-expert model that mimics the behavior of an expert user in an extended session consisting of queries, query refinements, and result-navigation steps. The enhanced PageRank scores, coined QRank scores, can be computed offline; at query-time they are combined with query-specific relevance measures with virtually no overhead. Our preliminary experiments, based on real-life query-log and click-stream traces from eight different trial users indicate significant improvements in the precision of search results.
Full-text · Article · Oct 2004 · Lecture Notes in Computer Science
[Show abstract][Hide abstract] ABSTRACT: The design and implementation of an event-trigger-rule-based auction system called IntelliBid are discussed. A network of knowledge web servers, each consisting of a web server, an event-trigger-rule (ETR) server, an event engine, a knowledge profile manager and bid servers and their proxies constitutes IntelliBid. Together, they provide auction-related services to the creator of an auction site and the bidders and suppliers of products. IntelliBid offers a number of desirable features such as offers flexibility to bidders for defining their own rules to control their bids in an automatic bidding process and furnishes valuable statistical information about past auctions.
[Show abstract][Hide abstract] ABSTRACT: Web services technology is emerging as a promising infrastructure to support loosely coupled, Internet-based applications that are distributed, heterogeneous, and dynamic. It provides a standards-based, process-centric framework for achieving the sharing of distributed heterogeneous applications. While Web services technology provides a promising foundation for developing distributed applications for e-business, additional features are required to make this paradigm truly useful in the real world. In particular, interactions among business organizations need to follow the policies, regulations, security and other business rules of the organizations. An effective way to control, restrict and enforce business rules in the use of Web services is to integrate business event and rule management concepts and techniques into the Web services model. In this paper, we focus on incorporating the business event and rule-management concepts into the Web services model at the service provider side. Based on a code-generation approach, we have developed techniques and implemented tools to generate Web service "wrappers" and other objects required to integrate an Event-Trigger-Rule (ETR) technology with the Web services technology.
No preview · Article · Jan 2004 · International Journal of Web Services Research
[Show abstract][Hide abstract] ABSTRACT: With the popularity of the Web services technology, more and more software systems?functionalities become available by being published and registered as Web services. Registered Web services need to be dynamically combined to form composite services when individual simple services fail to meet service requestors?complex service needs. In this article, we propose a semi-automatic approach to composite Web services discovery, description and invocation. We present an intelligent registry with constraint matching capabilities to support composite service discovery and description. It provides a user interface to interactively compose a service request. It then uses a semi-automatic mechanism and a search algorithm to construct a composite service template that satisfies the request. The operations of the template are bound to registered service operations by constraint matching subsequently. The resulting composite service is specified in the Web Services Flow Language. A composite service processor is designed to execute composite services by invoking the component service operations of various service providers.
Full-text · Article · Jan 2004 · International Journal of Web Services Research
[Show abstract][Hide abstract] ABSTRACT: This paper discusses the detection and management of a soybean rust outbreak in the context of agricultural homeland security. An Event-Trigger-Rule system is used for event registration, filtering and notification, and for process coordination and enforcement of agencies' policies, constraints, regulations and data integrity/security/privacy. A 'Response and Action Plan' for combating the disease proposed by one of the 12 member states of the Southern Plant Diagnostic Network is used in a prototype implementation to demonstrate the utility of the system.
[Show abstract][Hide abstract] ABSTRACT: Business organizations are often faced with decision situations in which the costs and benefits of some competing business specifications such as business offers, product specifications, or negotiation proposals need to be evaluated in order to select the best or desirable ones. In e-business, there is a need to automate the cost–benefit evaluation process to support decision making. This paper presents a general-purpose Cost–Benefit Evaluation Server (CBES) and its underlying Cost–Benefit Decision Model (CBDM), which models benefits in terms of costs and logical scoring and aggregation of preferences associated with products and services. The Server provides build-time tools for users to specify preference and cost information and a run-time engine to perform cost–benefit evaluations. A business scenario involving supplier selection and automated negotiation is given to illustrate the application of the Server and its four evaluation modes.
Preview · Article · Sep 2003 · Decision Support Systems
[Show abstract][Hide abstract] ABSTRACT: This paper describes an on-going effort to investigate problems and approaches for achieving Web-service-based, dynamic and collaborative e-learning. In this work, a Learning Content Definition Model is used to model distributed and sharable learning resources as content objects. Distributed and sharable software systems/components for supporting e-learning are modeled as software objects. Both types of objects are uniformly published as Web-services in a constraint-based Web-service registry and made sharable and reusable. An extended Web-service infrastructure provides a standard framework for the modeling, registration, discovery, binding and invocation of these objects. In this work, we also introduce a Learning Process Definition Model and a Learning Process Execution Engine for specifying and executing learning process models, which represent instructional modules in the forms of activity trees. An Event-Trigger-Rule Server is integrated with the Learning Process Execution Engine to make learning process models active, flexible, customizable and adaptable. It is also used to facilitate the interaction and coordination among learners, administrators, authors, and other personnel involved in collaborative e- learning.
[Show abstract][Hide abstract] ABSTRACT: This paper presents an infrastructure and a mechanism for achieving dynamic Inter-enterprise workflow management using e-services provided by collaborative e-business enterprises. E-services are distributed services that can be accessed programmatically on the Internet, using SOAP messages and the HTTP protocol. In this work, we categorize e-services according to their business types and manage them in a UDDI-enabled constraint-based Broker Server. E-service requests are specified in the activities of a process model according to some standardized e-service templates and are bound to the proper service providers at run-time by using a constraint-based, dynamic service binding mechanism. The workflow management system is dynamic in the sense that the actual business organizations, which take part in a business process, are not determined until run-time. We have extended the traditional workflow process modeling by including e-service requests in activity specifications and extended the Web Service Description Language (WSDL) by including constraints in both service specifications and service requests so that the selection of e-service providers can be more accurately performed.
Preview · Article · Dec 2002 · Electronic Commerce Research
[Show abstract][Hide abstract] ABSTRACT: The emerging Web service technology has enabled the development of Internet-based applications that integrate distributed
and heterogeneous systems and processes which are owned by different organizations. Compared to centralized systems and client-server
environments, the Web service environment is much more dynamic and security for such an environment poses unique challenges.
For example, an organization (e.g., a service provider or a service broker) cannot predetermine the users of its resources
and fix their access privileges. Also, service providers come and go. The users of services must have some assurances about
the services and the organizations that provide the services. Thus, the enforcement of security constraints cannot be static
and tightly coupled. The notion of trust agreement must be established to delegate the responsibility of certification of
unknown users, services, and organizations. In this paper, we describe a Trust-based Security Model (TSM) that incorporate
the traditional security concepts (e.g., roles, resources, operations) with new security concepts that are specific to the
Web service environment. The security concepts of TSM are then applied to the general Web service model to include security
considerations. Finally, an event-driven, rule-based approach to the enforcement of security in a Web service environment
[Show abstract][Hide abstract] ABSTRACT: This paper presents a solution to achieve dynamic Inter-enterprise workflow management using the eservices provided by collaborative e-business enterprises. E-services are distributed services that can be accessed programmatically on the Internet, using SOAP messages and the HTTP protocol. We categorize e-services according to their business types and manage them in an UDDI-enabled Broker Server. By E-service requests are specified in the activities of a process model according to some standardized e-service templates and are bound to the proper service providers at run-time by using a constraint-based, dynamic service binding mechanism. The workflow management system is dynamic in the sense that the actual business organizations that take part in a business process are not determined until run-time.
[Show abstract][Hide abstract] ABSTRACT: As the global marketplace becomes more and more competitive, business organizations often need to team up and operate as a virtual enterprise in order to utilize the best of their resources for achieving their common business goals. Since the business environment of a virtual enterprise is highly dynamic, it is necessary to develop a workflow management technology that is capable of handling dynamic workflows across enterprise boundaries. This paper describes a dynamic workflow model (DWM) and a dynamic workflow management system (DynaFlow) for modeling and controlling the execution of inter-organizational business processes. DWM enables the specification of dynamic properties associated with a business process model. It extends the underlying model of the WfMC's WPDL by adding connectors, events, triggers, and rules as its modeling constructs, encapsulating activity definitions, and allowing e-service requests to be included as a part of the activity specification. Using DWM as the underlying model, DynaFlow makes use of an event and rule server to trigger rules during the enactment of a workflow process to enforce business constraints and policies and/or to modify the process model at run-time. A constraint-based, dynamic service binding mechanism is used to dynamically bind e-service requests to e-services that satisfy some constraint specifications. Index Items: dynamic workflow model, dynamic workflow management system, business process, e-service, e-service constraint, e-service request constraint, business event, business rule, dynamic service binding. 3 1.
[Show abstract][Hide abstract] ABSTRACT: In recent years, there has been increasing interest in the specification, generation and exchange of business ob-jects in the context of electronic commerce. Common business objects have been defined for product catalogs, purchase orders and other business entities. However, no business objects have been defined and implemented for supporting automated business negotiations even though business negotiation is very much an integral part of business activities. In this work, we have designed and implemented a set of business negotiation objects for supporting the bargaining type of business negotiations. These objects define the operations and information contents needed for negotiation parties to express their requirements and constraints during a bargaining proc-ess. They correspond to a set of negotiation primitives, which is a superset of the negotiation-related primitives defined in two popular languages: ACL and COOL. The implementation of these objects is patterned after the business object documents in the XML format proposed by the Open Applications Group, thus conforming to the established standard. The incorporation of several types of constraint specifications in these business nego-tiation objects provides the negotiation parties and the negotiation servers that represent them much expressive power in specifying call-for-proposals and proposals. Two synchronization problems and their solutions associ-ated with the withdrawal and modification of negotiation proposals are addressed and presented in this paper. The use of these business negotiation objects in a bilateral bargaining protocol is also presented. We have vali-dated the utility of these objects in an integrated network environment, which consists of two replicated negotia-tion servers, two commercial products, and some other university research systems that form a supply chain.
Preview · Article · Jan 2002 · Group Decision and Negotiation
[Show abstract][Hide abstract] ABSTRACT: When different business organizations come together to conduct a joint business in a virtual enterprise environment, their application systems need to have a convenient way to specify the services needed from other systems and to transfer data needed by these services. The transferred data needs to be validated and, in some cases, mediated to meet the constraints and data representation requirements of both the source and target application systems. Ideally, the validation and mediation tasks should be done outside of the legacy application systems so that these systems do not have to be modified. In this work, the Business Object Documents (BODs) introduced by the Open Applications Group (OAG) are used for specifying business operations and transferring data among application systems. We use an active object model to model BODs. The model captures not only the data attributes and methods associated with these business objects, but also events and rules for specifying and triggering the enforcement of attribute constraints and inter-attribute constraints and the activation of data mediation operations. The conceptual models of these BODs with their added semantics are used to generate entity classes, converters and skeletal programs needed for enforcing constraints and for converting data. These generated object classes and software components in Java constitute the platform-independent adapters through which heterogeneous application systems inter-operate over CORBA and RMI communication infrastructures. A distributed approach to data validation and mediation is used. It allows the generated code for validation and mediation to be distributed and processed at different sites, thus avoiding the potential network bottleneck of a centralized approach to the validation and mediation of business object documents.
No preview · Article · Sep 2001 · Journal of Systems Integration
[Show abstract][Hide abstract] ABSTRACT: This paper describes the design and implementation of a replicable, Internet-based negotiation server for conducting bargaining-type
negotiations between enterprises involved in e-commerce and e-business. Enterprises can be buyers and sellers of products/services
or participants of a complex supply chain engaged in purchasing, planning, and scheduling. Multiple copies of our server can
be installed to complement the services of Web servers. Each enterprise can install or select a trusted negotiation server
to represent his/her interests. Web-based GUI tools are used during the build-time registration process to specify the requirements,
constraints, and rules that represent negotiation policies and strategies, preference scoring of different data conditions,
and aggregation methods for deriving a global cost-benefit score for the item(s) under negotiation. The registration information
is used by the negotiation servers to automatically conduct bargaining type negotiations on behalf of their clients. In this
paper, we present the architecture of our implementation as well as a framework for automated negotiations, and describe a
number of communication primitives which are used in the underlying negotiation protocol. A constraint satisfaction processor
(CSP) is used to evaluate a negotiation proposal or counterproposal against the registered requirements and constraints of
a client company. In case of a constraint violation, an event is posted to trigger the execution of negotiation strategic
rules, which either automatically relax the violated constraint, ask for human intervention, invoke an application, or perform
other remedial operations. An Event-Trigger-Rule (ETR) server is used to manage events, triggers, and rules. Negotiation strategic
rules can be added or modified at run-time. A cost-benefit analysis component is used to perform quantitative analysis of
alternatives. The use of negotiation servers to conduct automated negotiation has been demonstrated in the context of an integrated
supply chain scenario.