Alert-Driven Process Integration in a Web Services Environment

title: A three-layer architecture for e-contract enforcement in an e-service environment
abstract: In an e-service environment, contracts are important for attaining business process interoperability and enforcing their proper enactment.  In the document layer, contracts are composed of different types of clauses. In the business layer, e-contract enforcement activities are defined through the realization of contract clauses as business rules in event-condition-action (ECA) form. In the implementation layer, cross-organizational e-contract enforcement interfaces are implemented with contemporary Enterprise Java Bean and Web services. We present a methodology for the engineering of e-contracts enforcement from a high-level document-view down to the implementation layer based on this architecture, using a supply-chain example. As a result, e-contracts can be seamlessly defined and enforced. Conceptual models of various layers are given in the Unified Modeling Language (UML).

title: Developing a Distributed e-Monitoring System for Enterprise Website and Web Services: An Experience Report with Free Libraries and Tools
abstract: Enterprises value monitoring as it provides dependable e-services, whether it is an interactive Web site or programmatic Web service. However, this task becomes non-trivial when enterprises begin to require support from thousands of servers across geographical areas. How can the communications between a monitoring systems and remote servers be minimized? Could the task be achieved easily based on a readily available technology such as SNMP? How can we monitor thousands of servers powered by, say, Tomcat, which lacks SNMP support? How may a poorly responsive site be identified prior to being reported as a failure by SNMP? In this paper, we propose a unified e-monitoring system that enables system administrators to remotely monitor the health of distributed e-services in both the form of Web site and Web services. We further discuss our implementation experience based on a pragmatic prototype.

title: Checking safety properties using compositional reachability analysis
abstract: The software architecture of a distributed program can be represented by a hierarchical composition of subsystems, with interacting processes at the leaves of the hierarchy. Compositional reachability analysis (CRA) is a promising state reduction technique which can be automated and used in stages to derive the overall behavior of a distributed program based on its architecture. CRA is particularly suitable for the analysis of programs that are subject to evolutionary change. When a program evolves, only the behaviors of those subsystems affected by the change need be reevaluated. The technique however has a limitation. The properties available for analysis are constrained by the set of actions that remain globally observable. Properties involving actions encapsulated by subsystems may therefore not be analyzed. In this article, we enhance the CRA technique to check safety properties which may contain actions that are not globally observable. To achieve this, the state machine model is augmented with a special trap state labeled as π. We propose a scheme to transform, in stages, a property that involves hidden actions to one that involves only globally observable actions. The enhanced technique also includes a mechanism aiming at reducing the debugging effort. The technique is illustrated using a gas station system example.

title: A Multi-Agent Infrastructure for Mobile Workforce Management in a Service Oriented Enterprise
abstract: With recent advances in mobile technologies and infrastructures, there are increasing demands for the support of mobile workforce management (MWM) across multiple platforms. Mobile users can interact with the MWM system through SMS messages or Web browsers from personal computers, PDA devices, or WAP phones. MWM typically involves tight collaboration, negotiation, and sophisticated business domain knowledge. Therefore, the main challenge of MWM for a service oriented enterprise is the integration of disparate business function for its mobile professional workforce and the management with a unified infrastructure, together with the provision of personalized assistance and automation. These requirements can be facilitated with the use of intelligent software agents, but has not been adequately studied before. As mobile devices become more powerful, intelligent software agents can now be deployed on these devices and hence also subject to mobility. Thus, MWM systems have to accommodate these requirements as well as the support of heterogeneous platforms. In this paper, we formulate a scalable, flexible, and intelligent multi-agent information system (MAIS) infrastructure for MWM with agent clusters in the context of a large service oriented enterprise. Each agent cluster comprise several types of agents to achieve the goal of each phase of the workforce management process, namely, task formulation, matchmaking, brokering, commuting, and service. We evaluate our approach against different stakeholders' perspective.

title: Exploiting automatic analysis of e-commerce protocols
abstract: While e-commerce continuously grows prosperous, some advantages e-commerce applications claimed haven't really been gained. More seriously, the availability and reliability of these systems are particularly hard to obtain. The e-commerce protocols, as the core of e-commerce applications, ask for new development approach and techniques to be introduced for their highly reliable and safe design and implementation. This paper describes research on synthesis of extended UML formalism and formal verification techniques for automatic development of e-commerce protocols. In this paper, we refine AUML protocol diagrams for visual modeling, and develop algorithm and rules to translate visually modeled e-commerce protocols into formal models that are then validated using model checking. This approach is applied to the design of an e-commerce protocol, NetBill, as example. Our objective is to create tools that enable designers to automatically develop available and reliable e-commerce protocols.

title: Fast similarity search on video signatures
abstract: Video signatures are compact representations of video sequences designed for efficient similarity measurement. In this paper, we propose a feature extraction technique to support fast similarity search on large databases of video signatures. Our proposed technique transforms the high dimensional video signatures into low dimensional vectors where similarity search can be efficiently performed. We exploit both the upper and lower bounds of the triangle inequalities in approximating the high-dimensional metric, and combine this approximation with the classical PCA to achieve the target dimension. Experimental results on a large set of Web video sequences show that our technique outperforms fastmap, Haar wavelet, PCA, and triangle-inequality pruning.

title: Denial of service against the Domain Name System
abstract: Because many network services rely on the Domain Name System, denial-of-service attacks against it can be particularly damaging. This article analyzes such threats and reviews existing and proposed countermeasures for addressing them.

title: Multiple forecasts with autoregressive time series models: case studies
abstract: It is indisputable that accurate forecasts of economic activities are vital to successful business and government policies. In many circumstances, instead of a single forecast, simultaneous prediction intervals for multiple forecasts are more useful to decision-makers. For example, based on previous monthly sales records, a production manager would be interested in the next 12 interval forecasts of the monthly sales using for the annual inventory and manpower planning. For Gaussian autoregressive time series processes, several procedures for constructing simultaneous prediction intervals have been proposed in the literature. These methods assume a normal error distribution and can be adversely affected by departures from normality which are commonly encountered in business and economic time series. In this article, we explore the bootstrap methods for the construction of simultaneous multiple interval forecasts. To understand the mechanisms and characteristics of the proposed bootstrap procedures, several macro-economic time series are selected for illustrative purposes. The selected series are fitted reasonably well with autoregressive models which form an important class in time series. As a matter of fact, the major ideas discussed in this paper with autoregressive processes can be extended to other more complicated time series models.

title: Routing with Locality on Meshes with Buses
abstract: Routing with locality is studied for meshes with buses. In this problem, packets' distances are bounded by a value,d, which is less than the diameter of the network. This problem arises naturally when specific known algorithms are implemented on meshes. Solving this problem in ordinary meshes requires at least a routing time ofdsteps. To do better than this, we propose adding a kind of short bus to ordinary meshes. By using a technique which we call iterative walk-and-ride, we show how the routing time can be reduced by approximately one-third for solving the problem (including the multipacket version) on one- and two-dimensional short-bus meshes. The bounds we develop are tight.

title: Insensitive bounds for the moments of the sojourn time distribution in the M/G/1 processor-sharing queue
abstract: This paper studies the M/G/1 processor-sharing (PS) queue, in particular the sojourn time distribution conditioned on the initial job size. Although several expressions for the Laplace-Stieltjes transform (LST) are known, these expressions are not suitable for computational purposes. This paper derives readily applicable insensitive bounds for all moments of the conditional sojourn time distribution. The instantaneous sojourn time, i.e., the sojourn time of an infinitesimally small job, leads to insensitive upper bounds requiring only knowledge of the traffic intensity and the initial job size. Interestingly, the upper bounds involve polynomials with so-called Eulerian numbers as coefficients. In addition, stochastic ordering and moment ordering results for the sojourn time distribution are obtained.