Specification Of Control Flow Research Articles

WS-Data Model: A Data Model for Web Services Composition and Optimization

Recent enthusiasm in service science attracts more attention on the design and analysis of service systems. A service system, from the engineering point of view, can be regarded as the interactions between various service elements, and service elements can be innovatively assembled to provide customizable services. To embody service elements in service-oriented architecture, Web services that conform to industrial standard have been proposed and widely adopted, and many researches are devoted into automatic Web service composition. However, most of these researches focus on control flow specification and enforcement. Data mismatch between Web services appears as an orthogonal problem that can be solved using XML-based query languages. We argue that greater optimization is possible if Web service composition can be considered into data manipulation operations. A proposed model, the WS-data model, focuses on data exchanges in composing Web services. Several operators with varying properties can compose Web services and manipulate their input and output data. Experiments conducted on the Amazon Cloud platform show that these operators’ properties can help identify a more efficient way to realize a complex task, expressed according to the proposed WS-data model.

A rigorous approach to facilitate and guarantee the correctness of the genetic testing management in human genome information systems

BackgroundRecent medical and biological technology advances have stimulated the development of new testing systems that have been providing huge, varied amounts of molecular and clinical data. Growing data volumes pose significant challenges for information processing systems in research centers. Additionally, the routines of genomics laboratory are typically characterized by high parallelism in testing and constant procedure changes.ResultsThis paper describes a formal approach to address this challenge through the implementation of a genetic testing management system applied to human genome laboratory. We introduced the Human Genome Research Center Information System (CEGH) in Brazil, a system that is able to support constant changes in human genome testing and can provide patients updated results based on the most recent and validated genetic knowledge. Our approach uses a common repository for process planning to ensure reusability, specification, instantiation, monitoring, and execution of processes, which are defined using a relational database and rigorous control flow specifications based on process algebra (ACP). The main difference between our approach and related works is that we were able to join two important aspects: 1) process scalability achieved through relational database implementation, and 2) correctness of processes using process algebra. Furthermore, the software allows end users to define genetic testing without requiring any knowledge about business process notation or process algebra.ConclusionsThis paper presents the CEGH information system that is a Laboratory Information Management System (LIMS) based on a formal framework to support genetic testing management for Mendelian disorder studies. We have proved the feasibility and showed usability benefits of a rigorous approach that is able to specify, validate, and perform genetic testing using easy end user interfaces.

Improving process models by discovering decision points

Workflow management systems (WfMS) are widely used by business enterprises as tools for administrating, automating and scheduling the business process activities with the available resources. Since the control flow specifications of workflows are manually designed, they entail assumptions and errors, leading to inaccurate workflow models. Decision points, the XOR nodes in a workflow graph model, determine the path chosen toward completion of any process invocation. In this work, we show that positioning the decision points at their earliest points can improve process efficiency by decreasing their uncertainties and identifying redundant activities. We present novel techniques to discover the earliest positions by analyzing workflow logs and to transform the model graph. The experimental results show that the transformed model is more efficient with respect to its average execution time and uncertainty, when compared to the original model.

A REUSE-ORIENTED WORKFLOW DEFINITION LANGUAGE

This paper presents a new formalism for workflow process definition, which combines research in programming languages and in database systems. This formalism is based on creating a library of workflow building blocks, which can be progressively combined and nested to construct complex workflows. Workflows are specified declaratively, using a simple high level language, which allows the dynamic definition of exception handling and events, as well as dynamically overriding workflow definition. This ensures a high degree of flexibility in data and control flow specification, as well as in reuse of workflow specifications to construct other workflows. The resulting workflow execution environment is well suited to supporting cooperative work.

Organizing long-running activities with triggers and transactions

This paper addresses the problem of organising and controlling activities that involve multiple steps of processing and that typically are of long duration. We explore the use of triggers and transactions to specify and organize such long-running activities. Triggers offer data- or event-driven specification of control flow, and thus provide a flexible and modular framework with which the control structures of the activities can be extended or modified. We describe a model based on event-condition-action rules and coupling modes. The execution of these rules is governed by an extended nested transaction model. Through a detailed example, we illustrate the utility of the various features of the model for chaining related steps without sacrificing concurrency, for enforcing integrity constraints, and for providing flexible failure and exception handling.

Automated Protocol Validation in Argos: Assertion Proving and Scatter Searching

Argos is a validation language for data communication protocols. To validate a protocol, a model in Argos is constructed consisting of a control flow specification and a formal description of the correctness requirements. This model can be compiled into a minimized lower level description that is based on a formal model of communicating finite state machines. An automated protocol validator trace uses these minimized descriptions to perform a partial symbolic execution of the protocol to establish its correctness for the given requirements.