1,417 research outputs found

    COWS: A Timed Service-Oriented Calculus

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    COWS (Calculus for Orchestration of Web Services) is a foundational language for Service Oriented Computing that combines in an original way a number of ingredients borrowed from well-known process calculi, e.g. asynchronous communication, polyadic synchronization, pattern matching, protection, delimited receiving and killing activities, while resulting different from any of them. In this paper, we extend COWS with timed orchestration constructs, this way we obtain a language capable of completely formalizing the semantics of WS-BPEL, the ‘de facto’ standard language for orchestration of web services. We present the semantics of the extended language and illustrate its peculiarities and expressiveness by means of several examples

    A WSDL-Based Type System for WS-BPEL

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    We tackle the problem of providing rigorous formal foundations to current software engineering technologies for web services. We focus on two of the most used XML-based languages for web services: WSDL and WS-BPEL. To this aim, first we select an expressive subset of WS-BPEL, with special concern for modeling the interactions among web service instances in a network context, and define its operational semantics. We call ws-calculus the resulting formalism. Then, we put forward a rigorous typing discipline that formalizes the relationship existing between ws-calculus terms and the associated WSDL documents and supports verification of their compliance. We prove that the type system and the operational semantics of ws-calculus are ‘sound’ and apply our approach to an example application involving three interacting web services

    Using formal methods to develop WS-BPEL applications

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    In recent years, WS-BPEL has become a de facto standard language for orchestration of Web Services. However, there are still some well-known difficulties that make programming in WS-BPEL a tricky task. In this paper, we firstly point out major loose points of the WS-BPEL specification by means of many examples, some of which are also exploited to test and compare the behaviour of three of the most known freely available WS-BPEL engines. We show that, as a matter of fact, these engines implement different semantics, which undermines portability of WS-BPEL programs over different platforms. Then we introduce Blite, a prototypical orchestration language equipped with a formal operational semantics, which is closely inspired by, but simpler than, WS-BPEL. Indeed, Blite is designed around some of WS-BPEL distinctive features like partner links, process termination, message correlation, long-running business transactions and compensation handlers. Finally, we present BliteC, a software tool supporting a rapid and easy development of WS-BPEL applications via translation of service orchestrations written in Blite into executable WS-BPEL programs. We illustrate our approach by means of a running example borrowed from the official specification of WS-BPEL

    Specifying and Analysing SOC Applications with COWS

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    COWS is a recently defined process calculus for specifying and combining service-oriented applications, while modelling their dynamic behaviour. Since its introduction, a number of methods and tools have been devised to analyse COWS specifications, like e.g. a type system to check confidentiality properties, a logic and a model checker to express and check functional properties of services. In this paper, by means of a case study in the area of automotive systems, we demonstrate that COWS, with some mild linguistic additions, can model all the phases of the life cycle of service-oriented applications, such as publication, discovery, negotiation, orchestration, deployment, reconfiguration and execution. We also provide a flavour of the properties that can be analysed by using the tools mentioned above

    The Sensoria Approach Applied to the Finance Case Study

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    This chapter provides an effective implementation of (part of) the Sensoria approach, specifically modelling and formal analysis of service-oriented software based on mathematically founded techniques. The ‘Finance case study’ is used as a test bed for demonstrating the feasibility and effectiveness of the use of the process calculus COWS and some of its related analysis techniques and tools. In particular, we report the results of an application of a temporal logic and its model checker for expressing and checking functional properties of services and a type system for guaranteeing confidentiality properties of services

    Service discovery and negotiation with COWS

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    To provide formal foundations to current (web) services technologies, we put forward using COWS, a process calculus for specifying, combining and analysing services, as a uniform formalism for modelling all the relevant phases of the life cycle of service-oriented applications, such as publication, discovery, negotiation, deployment and execution. In this paper, we show that constraints and operations on them can be smoothly incorporated in COWS, and propose a disciplined way to model multisets of constraints and to manipulate them through appropriate interaction protocols. Therefore, we demonstrate that also QoS requirement specifications and SLA achievements, and the phases of dynamic service discovery and negotiation can be comfortably modelled in COWS. We illustrate our approach through a scenario for a service-based web hosting provider

    Food insecurity programs in Broome County schools

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    Food insecurity is a serious problem in schools across Broome County, and the programs implemented to mitigate its effects must be researched and assessed for their effectiveness. Food insecurity affects hundreds of children throughout the county, causing health effects like diabetes and a drop in academic performance. The programs that work to lessen these effects in Broome County, including the Rock on Café and Binghamton University Food Pantry, aim to provide nutritional and affordable food to students on all educational levels. In order to assess these programs, I am interviewing organizers of such programs and asking them questions to gather qualitative data on the effects of food insecurity. Additionally, I am utilizing survey results of Binghamton University students and studies on Broome County food insecurity to find both qualitative and quantitative data for evaluation. I intend to find statistics on the number of students that require such programs and the nutritional level of the food provided within the interviews and survey. In interviewing those involved in the food insecurity programs, I will have descriptions of the workings of these programs and how effective they have found them to be in increasing academic performance and decreasing adverse health effects. Based on literature review and preliminary data, it seems while there are an abundance of food deserts within Broome County, the food supplement programs are providing nutritional food to many students while continually expanding the programs to reach a broader population. This research will provide an overview of the current situation of food insecurity in Broome County schools and how effectively it is being managed through statistics on students utilizing the program and the perspective of individuals who see the program in use.https://orb.binghamton.edu/research_days_posters_2021/1020/thumbnail.jp

    GlySpy: A software suite for assigning glycan topologies from sequential mass spectral data

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    GlySpy is a suite of algorithms used to determine the structure of glycans. Glycans, which are orderly aggregations of monosaccharides such as glucose, mannose, and fucose, are often attached to proteins and lipids, and provide a wide range of biological functions. Previous biomolecule-sequencing algorithms have operated on linear polymers such as proteins or DNA but, because glycans form complicated branching structures, new approaches are required. GlySpy uses data derived from sequential mass spectrometry (MSn), in which a precursor molecule is fragmented to form products, each of which may then be fragmented further, gradually disassembling the glycan. GlySpy resolves the structures of the original glycans by examining these disassembly pathways. The four main components of GlySpy are: (1) OSCAR (the Oligosaccharide Subtree Constraint Algorithm), which accepts analyst-selected MSn disassembly pathways and produces a set of plausible glycan structures; (2) IsoDetect, which reports the MSn disassembly pathways that are inconsistent with a set of expected structures, and which therefore may indicate the presence of alternative isomeric structures; (3) IsoSolve, which attempts to assign the branching structures of multiple isomeric glycans found in a complex mixture; and (4) Intelligent Data Acquisition (IDA), which provides automated guidance to the mass spectrometer operator, selecting glycan fragments for further MSn disassembly. This dissertation provides a primer for the underlying interdisciplinary topics---carbohydrates, glycans, MSn, and so on-and also presents a survey of the relevant literature with a focus on currently-available tools. Each of GlySpy\u27s four algorithms is described in detail, along with results from their application to biologically-derived glycan samples. A summary enumerates GlySpy\u27s contributions, which include de novo glycan structural analysis, favorable performance characteristics, interpretation of higher-order MSn data, and the automation of both data acquisition and analysis

    A Calculus for Orchestration of Web Services

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    Service-oriented computing, an emerging paradigm for distributed computing based on the use of services, is calling for the development of tools and techniques to build safe and trustworthy systems, and to analyse their behaviour. Therefore, many researchers have proposed to use process calculi, a cornerstone of current foundational research on specification and analysis of concurrent, reactive, and distributed systems. In this paper, we follow this approach and introduce CWS, a process calculus expressly designed for specifying and combining service-oriented applications, while modelling their dynamic behaviour. We show that CWS can model all the phases of the life cycle of service-oriented applications, such as publication, discovery, negotiation, orchestration, deployment, reconfiguration and execution. We illustrate the specification style that CWS supports by means of a large case study from the automotive domain and a number of more specific examples drawn from it
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