19,524 research outputs found

    Implementing atomic actions in Ada 95

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    Atomic actions are an important dynamic structuring technique that aid the construction of fault-tolerant concurrent systems. Although they were developed some years ago, none of the well-known commercially-available programming languages directly support their use. This paper summarizes software fault tolerance techniques for concurrent systems, evaluates the Ada 95 programming language from the perspective of its support for software fault tolerance, and shows how Ada 95 can be used to implement software fault tolerance techniques. In particular, it shows how packages, protected objects, requeue, exceptions, asynchronous transfer of control, tagged types, and controlled types can be used as building blocks from which to construct atomic actions with forward and backward error recovery, which are resilient to deserter tasks and task abortion

    Websites as Facilities Under ADA Title III

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    Title III of the Americans with Disabilities Act requires public accommodations—private entities that offer goods or services to the public—to be accessible to individuals with disabilities. There is an ongoing debate about whether Title III applies to websites that offer services to the public, but this debate may be resolved in the coming years by litigation or Department of Justice regulations. Assuming for the sake of argument that Title III will eventually be applied to websites, the next inquiry is what that application should look like. The regulatory definition of “facilities” should be amended to include nonphysical places of public accommodations. This change would open the door to a multilayered approach to accessible websites, wherein existing websites are subject to relatively lax requirements but new and altered websites are subject to stricter requirements

    The Framework Directive for equal treatment in employment and occupation: an analysis from a disability rights perspective

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    The purpose of this paper is to analyse the recently adopted directive establishing a general framework for equal treatment in employment and occupation from a disability rights perspective. The adoption of this directive represents merely the first stage in the prohibition of discrimination on the grounds falling within its protective remit. The next and arguably most important stage is the implementation of this directive into national law. Of the protected grounds, disability offers what is arguably the greatest challenge for national authorities in the implementation process. It demands flexibility in the legislative approach traditionally used to combat discrimination as well as the introduction of new legal concepts into the national legal order of most Member States. Whilst European Disability Non-Governmental Organisations, together with the European Parliament, are calling on the Commission of the European Union to propose a more expansive directive prohibiting disability discrimination, it is first crucial to ensure that the core aspects of the recently adopted directive are clearly understood and correctly implemented from a disability rights perspective. These core aspects include the definition of disability, the concepts of direct and indirect discrimination, and the duty to provide reasonable accommodations. Given that these core aspects will be common to any disability non-discrimination law, no amount of coverage beyond the context of employment and occupation will compensate for the subsequent loss of opportunity to make a real difference to the lives of disabled people if they are not appropriately addressed.</p

    A distributed programming environment for Ada

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    Despite considerable commercial exploitation of fault tolerance systems, significant and difficult research problems remain in such areas as fault detection and correction. A research project is described which constructs a distributed computing test bed for loosely coupled computers. The project is constructing a tool kit to support research into distributed control algorithms, including a distributed Ada compiler, distributed debugger, test harnesses, and environment monitors. The Ada compiler is being written in Ada and will implement distributed computing at the subsystem level. The design goal is to provide a variety of control mechanics for distributed programming while retaining total transparency at the code level

    New York City Transit Authority and Subway Surface Supervisors Association (SSSA) (2003)

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    Development and Verification of a Flight Stack for a High-Altitude Glider in Ada/SPARK 2014

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    SPARK 2014 is a modern programming language and a new state-of-the-art tool set for development and verification of high-integrity software. In this paper, we explore the capabilities and limitations of its latest version in the context of building a flight stack for a high-altitude unmanned glider. Towards that, we deliberately applied static analysis early and continuously during implementation, to give verification the possibility to steer the software design. In this process we have identified several limitations and pitfalls of software design and verification in SPARK, for which we give workarounds and protective actions to avoid them. Finally, we give design recommendations that have proven effective for verification, and summarize our experiences with this new language

    Evolution of Ada technology in the flight dynamics area: Implementation/testing phase analysis

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    An analysis is presented of the software engineering issues related to the use of Ada for the implementation and system testing phases of four Ada projects developed in the flight dynamics area. These projects reflect an evolving understanding of more effective use of Ada features. In addition, the testing methodology used on these projects has changed substantially from that used on previous FORTRAN projects

    Study of fault-tolerant software technology

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    Presented is an overview of the current state of the art of fault-tolerant software and an analysis of quantitative techniques and models developed to assess its impact. It examines research efforts as well as experience gained from commercial application of these techniques. The paper also addresses the computer architecture and design implications on hardware, operating systems and programming languages (including Ada) of using fault-tolerant software in real-time aerospace applications. It concludes that fault-tolerant software has progressed beyond the pure research state. The paper also finds that, although not perfectly matched, newer architectural and language capabilities provide many of the notations and functions needed to effectively and efficiently implement software fault-tolerance

    Legal Solutions in Health Reform: Insurance Discrimination on the Basis of Health Status: An Overview of Discrimination Practices, Federal Law, and Federal Reform Options

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    Provides an overview of the insurance industry's discriminatory practices based on health status in designing and administering health insurance and employee health benefit plans. Discusses current federal law and interim and long-term reform options
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