688 research outputs found

    Implementing Session Centered Calculi

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    Recently, specific attention has been devoted to the development of service oriented process calculi. Besides the foundational aspects, it is also interesting to have prototype implementations for them in order to assess usability and to minimize the gap between theory and practice. Typically, these implementations are done in Java taking advantage of its mechanisms supporting network applications. However, most of the recurrent features of service oriented applications are re-implemented from scratch. In this paper we show how to implement a service oriented calculus, CaSPiS (Calculus of Services with Pipelines and Sessions) using the Java framework IMC, where recurrent mechanisms for network applications are already provided. By using the session oriented and pattern matching communication mechanisms provided by IMC, it is relatively simple to implement in Java all CaSPiS abstractions and thus to easily write the implementation in Java of a CaSPiS process

    A Flexible and Modular Framework for Implementing Infrastructures for Global Computing

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    We present a Java software framework for building infrastructures to support the development of applications for systems where mobility and network awareness are key issues. The framework is particularly useful to develop run-time support for languages oriented towards global computing. It enables platform designers to customize communication protocols and network architectures and guarantees transparency of name management and code mobility in distributed environments. The key features are illustrated by means of a couple of simple case studies

    Dataplane Specialization for High-performance OpenFlow Software Switching

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    OpenFlow is an amazingly expressive dataplane program- ming language, but this expressiveness comes at a severe performance price as switches must do excessive packet clas- sification in the fast path. The prevalent OpenFlow software switch architecture is therefore built on flow caching, but this imposes intricate limitations on the workloads that can be supported efficiently and may even open the door to mali- cious cache overflow attacks. In this paper we argue that in- stead of enforcing the same universal flow cache semantics to all OpenFlow applications and optimize for the common case, a switch should rather automatically specialize its dat- aplane piecemeal with respect to the configured workload. We introduce ES WITCH , a novel switch architecture that uses on-the-fly template-based code generation to compile any OpenFlow pipeline into efficient machine code, which can then be readily used as fast path. We present a proof- of-concept prototype and we demonstrate on illustrative use cases that ES WITCH yields a simpler architecture, superior packet processing speed, improved latency and CPU scala- bility, and predictable performance. Our prototype can eas- ily scale beyond 100 Gbps on a single Intel blade even with complex OpenFlow pipelines

    Distributed-Pair Programming can work well and is not just Distributed Pair-Programming

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    Background: Distributed Pair Programming can be performed via screensharing or via a distributed IDE. The latter offers the freedom of concurrent editing (which may be helpful or damaging) and has even more awareness deficits than screen sharing. Objective: Characterize how competent distributed pair programmers may handle this additional freedom and these additional awareness deficits and characterize the impacts on the pair programming process. Method: A revelatory case study, based on direct observation of a single, highly competent distributed pair of industrial software developers during a 3-day collaboration. We use recordings of these sessions and conceptualize the phenomena seen. Results: 1. Skilled pairs may bridge the awareness deficits without visible obstruction of the overall process. 2. Skilled pairs may use the additional editing freedom in a useful limited fashion, resulting in potentially better fluency of the process than local pair programming. Conclusion: When applied skillfully in an appropriate context, distributed-pair programming can (not will!) work at least as well as local pair programming

    Alat Pendeteksi Dini Gangguan Saluran Pernafasan Terintegrasi Cloud Storage

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    Technology advances very rapidly and currently can be implemented into every aspect of human life needs. This research seeks to take advantage of advances in technology to help meet human needs in the field of health. This tool uses the flowmeter sensor to measure the human breath that passes the sensor as input values will be processed by the system. Human breath volume value unit searched the time by using the principle of Bernoulli\u27s law of physical to detect any abnormalities in respiratory function in humans. With the possibility of it detects early these abnormalities will increase the effectiveness of treatments that can be given to sufferers. Measuring instrument is then integrated with database systems with cloud computing using the web server, so that the data collected through such tools can be sent directly to the database server and displayed through a Web page. Thus, parties concerned who have access rights to view this data can access that data anytime and anywhere. Making it easier to do preparation handling or even do prevention because it is an indication of the risk of disease can be detected early. The data can also be used as a record of statistical data for penilitian and logging that can be beneficial in the field of health. The results of this research is the integration of the two subsystems for measuring air flow and a data base of cloud computing. Hardware that is designed in such a way that it can ease of use and datas can be accessed any where are expected to provide a useful innovation which connects science in health and technology student works as a creation of Gadjah Mada Universit

    Event-B Patterns for Specifying Fault-Tolerance in Multi-Agent Interaction

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    Interaction in a multi-agent system is susceptible to failure. A rigorous development of a multi-agent system must include the treatment of fault-tolerance of agent interactions for the agents to be able to continue to function independently. Patterns can be used to capture fault-tolerance techniques. A set of modelling patterns is presented that specify fault-tolerance in Event-B specifications of multi-agent interactions. The purpose of these patterns is to capture common modelling structures for distributed agent interaction in a form that is re-usable on other related developments. The patterns have been applied to a case study of the contract net interaction protocol

    An open extensible tool environment for Event-B

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    Abstract. We consider modelling indispensable for the development of complex systems. Modelling must be carried out in a formal notation to reason and make meaningful conjectures about a model. But formal modelling of complex systems is a difficult task. Even when theorem provers improve further and get more powerful, modelling will remain difficult. The reason for this that modelling is an exploratory activity that requires ingenuity in order to arrive at a meaningful model. We are aware that automated theorem provers can discharge most of the onerous trivial proof obligations that appear when modelling systems. In this article we present a modelling tool that seamlessly integrates modelling and proving similar to what is offered today in modern integrated development environments for programming. The tool is extensible and configurable so that it can be adapted more easily to different application domains and development methods.

    Design approaches in technology enhanced learning

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    Design is a critical to the successful development of any interactive learning environment (ILE). Moreover, in technology enhanced learning (TEL), the design process requires input from many diverse areas of expertise. As such, anyone undertaking tool development is required to directly address the design challenge from multiple perspectives. We provide a motivation and rationale for design approaches for learning technologies that draws upon Simon's seminal proposition of Design Science (Simon, 1969). We then review the application of Design Experiments (Brown, 1992) and Design Patterns (Alexander et al., 1977) and argue that a patterns approach has the potential to address many of the critical challenges faced by learning technologists

    Attribute-Based Architecture Styles

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    Adenocarcinoma arising at ileostomy sites: Two cases and a review of the literature

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    Total colectomy with ileostomy placement is a treatment for patients with inflammatory bowel disease or familial adenomatous polyposis (FAP). A rare and late complication of this treatment is carcinoma arising at the ileostomy site. We describe two such cases: a 78-year-old male 30 years after subtotal colectomy and ileostomy for FAP, and an 85-year-old male 50 years after colectomy and ileostomy for ulcerative colitis. The long latency period between creation of the ileostomies and development of carcinoma suggests a chronic metaplasia due to an irritating/inflammatory causative factor. Surgical excision of the mass and relocation of the stoma is the mainstay of therapy, with possible benefits from adjuvant chemotherapy. Newly developed lesions at stoma sites should be biopsied to rule out the possibility of this rare ileostomy complication
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