47 research outputs found

    Web services approach for ambient assisted living in mobile environments

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    Web services appeared as a promising technology for Web environments independent of technologies, services, and applications. First, a performance comparison study between the two most used Web service architectures, SOAP and REST, is presented, considering messages exchange between clients and a server. Based on this study, the REST architecture was chosen to deploy the system because it gets better results compared to SOAP architecture. Currently, there are some issues related with this approach that should be studied. For instance, if massive quantities of data are sent to databases it can influence significantly the performance of the whole system. The Advanced Message Queuing Protocol (AMPQ) appears as a promising solution to address this problem. Then, in order to evaluate the performance of this approach, this work presents a performance evaluation and a comparison study of RESTful Web services and the AMQP Protocol considering exchanging messages between clients and a server. The study is based on the averaged exchanged messages for a certain period of time. It was observed and concluded that, for large quantities of messages exchange, the best results comes from the Advanced Message Queuing Protocol. Message Queuing Telemetry Transport (MQTT) was addressed in this work because it is a similar protocol to AMQP but it can be used by mobile devices with a processing capacity smallest unlike the AMQP that needs greater processing capacity. These studies are performed in the context of Ambient Assisted Living environments, since the work was applied to this topic in order to experiment the effectiveness and evaluate the performance of these protocols in this scenario

    Pharmacy perspectives in the design and implementation of a mobile cellular phone application as a communication aid for dispensing medicines to deaf people in the South African context

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    Doctor Pharmaceuticae - DPharmSouth Africa's White Paper for the transformation of the health care system in South Africa (DOH, 2007) acknowledges major disparities and inequalities as a result of an imprint by apartheid policies. In its transition to democracy, health promotion strategies have been initiated to address these disparities. However, such strategies have been narrowed and "favoured target audiences that are literate, urban-based and who have easy access to print and audio-visual media" (DOH, 1997). This implies that many vulnerable and marginalised groupings in South Africa, including the Deaf community are excluded from health promotion endeavours. Deaf people in South Africa communicate using South African Sign Language (SASL) and majority of the Deaf community exhibit poor literacy levels. Deafness is a significant communication barrier which limits a Deaf person's prospect to attain the best possible health care (Barnett, et al 2011). Various means of communication including spoken language, written instructions and the use of pictograms are used by healthcare workers to communicate health-related information. For many members of the Deaf community who communicate primarily in sign language, these methods are a sub-standard and prevent the attainment of optimum therapeutic outcomes. With regard to pharmaco-therapeutic services, Deaf people cannot hear the spoken language used by pharmacists during patient counselling, and their compromised functional literacy hinders the ability to read instructions on medicine labels. With both the spoken and written means of communication compromised, the Deaf patient's ability to comprehend instruction by pharmacists on how to use their medicines is inadequate and as a result, a Deaf patient may leave the pharmacy with medicine, but a poor understanding of how to use the medicine safely and effectively. Previous researchers have worked on building a technology base, including industrial design and computer science expertise to conceptualize the groundwork of a mobile phone application called SignSupport to facilitate communication between medical doctors and Deaf individuals. The particulars of the pharmacy scenario however, require a pharmacy-specific device to be of use in the dispensing of medicines to a Deaf patient in a pharmacy. The over-arching goal of this thesis is to design and evaluate a mobile phone application to facilitate the communication of medicine instructions between a Deaf patient and a pharmacist. Qualitative, participatory action research and community-based co-design strategies were directed toward Deaf participants, senior pharmacy students and pharmacists to create a prototype of the afore-mentioned mobile phone application. Preliminary results indicated that the application was suitable to pharmacists and Deaf community. Furthermore, both sets of users approved the overall design and were receptive to and keen on the practical uses of the application. Inadequacies pointed out by the Deaf community and pharmacists were addressed as an iterative modification to the prototype and culminated in version 2 which was deployed in an actual hospital pharmacy in 2015. Hospital usability studies generated largely positive results from both Deaf users and pharmacists, indicating that SignSupport is able to facilitate communication between pharmacists and Deaf patients. Next steps include advancing the application to a market–ready version that is downloadable and available as an application on the play stores of commercially available smart phones.National Research Foundatio

    The use of mobile phones as service-delivery devices in sign language machine translation system

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    Masters of ScienceThis thesis investigates the use of mobile phones as service-delivery devices in a sign language machine translation system. Four sign language visualization methods were evaluated on mobile phones. Three of the methods were synthetic sign language visualization methods. Three factors were considered: the intelligibility of sign language, as rendered by the method; the power consumption; and the bandwidth usage associated with each method. The average intelligibility rate was 65%, with some methods achieving intelligibility rates of up to 92%. The average size was 162 KB and, on average, the power consumption increased to 180% of the idle state, across all methods. This research forms part of the Integration of Signed and Verbal Communication: South African Sign Language Recognition and Animation (SASL) project at the University of the Western Cape and serves as an integration platform for the group's research. In order to perform this research a machine translation system that uses mobile phones as service-delivery devices was developed as well as a 3D Avatar for mobile phones. It was concluded that mobile phones are suitable service-delivery platforms for sign language machine translation systems.South Afric

    Large scale numerical software development using functional languages

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    PhD ThesisFunctional programming languages such as Haskell allow numerical algorithms to be expressed in a concise, machine-independent manner that closely reflects the underlying mathematical notation in which the algorithm is described. Unfortunately the price paid for this level of abstraction is usually a considerable increase in execution time and space usage. This thesis presents a three-part study of the use of modern purely-functional languages to develop numerical software. In Part I the appropriateness and usefulness of language features such as polymorphism. pattern matching, type-class overloading and non-strict semantics are discussed together with the limitations they impose. Quantitative statistics concerning the manner in which these features are used in practice are also presented. In Part II the information gathered from Part I is used to design and implement FSC. all experimental functional language tailored to numerical computing, motivated as much by pragmatic as theoretical issues. This language is then used to develop numerical software and its suitability assessed via benchmarking it against C/C++ and Haskell under various metrics. In Part III the work is summarised and assessed.EPSRC

    Decentralised Control Flow: A Computational Model for Distributed Systems

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    PhD ThesisThis thesis presents two sets of principles for the organisation of distributed computing systems. Details of models of computation based on these principles are together given, with proposals for programming languages based on each model of computation. The recursive control flow principles are based on the concept of recursive control flow computing system structuring. A recursive comprises a group of subordinate computing systems connected together by Each subordinate computing system may either be a communications medium. which a a computing system consists of a processing unit, memory some is itself a recursive component, and input/output devices, or computing components control flow system. The memory of all the computing systems within a recursive control flow computing subordinate system are arranged in a hierarchy. Using suitable addresses, any part of the hierarchy is accessible to any sequence of instructions which may be executed by the processing unit of a subordinate computing system. This rise to serious difficulties in the global accessibility gives understanding of programs written the meaning of in a programming language recursive control flow on the model of computation. based Reasoning about a particular program in isolation is difficult because of the potential interference between the execution different programs cannot be ignored . alternative principles, decentralised control flow, restrict the The accessibility of subordinate global the memory components of the computing The basis of the concept of objects forms the systems. principles. Information channels may flow along unnamed between instances of these objects, this being the only way in which one instance of an object may communicate with some other instance of an object. Reasoning particular program written in a programming language about a based on the decentralised control flow model of computation is easier since it is that there will be no interference between the guaranteed execution of different programs.Science and Engineering Research Council of Great Britain, International Computers Limite

    Algebraic Stream Processing

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    We identify and analyse the typically higher-order approaches to stream processing in the literature. From this analysis we motivate an alternative approach to the specification of SPSs as STs based on an essentially first-order equational representation. This technique is called Cartesian form specification. More specifically, while STs are properly second-order objects we show that using Cartesian forms, the second-order models needed to formalise STs are so weak that we may use and develop well-understood first-order methods from computability theory and mathematical logic to reason about their properties. Indeed, we show that by specifying STs equationally in Cartesian form as primitive recursive functions we have the basis of a new, general purpose and mathematically sound theory of stream processing that emphasises the formal specification and formal verification of STs. The main topics that we address in the development of this theory are as follows. We present a theoretically well-founded general purpose stream processing language ASTRAL (Algebraic Stream TRAnsformer Language) that supports the use of modular specification techniques for full second-order STs. We show how ASTRAL specifications can be given a Cartesian form semantics using the language PREQ that is an equational characterisation of the primitive recursive functions. In more detail, we show that by compiling ASTRAL specifications into an equivalent Cartesian form in PREQ we can use first-order equational logic with induction as a logical calculus to reason about STs. In particular, using this calculus we identify a syntactic class of correctness statements for which the verification of ASTRAL programmes is decidable relative to this calculus. We define an effective algorithm based on term re-writing techniques to implement this calculus and hence to automatically verify a very broad class of STs including conventional hardware devices. Finally, we analyse the properties of this abstract algorithm as a proof assistant and discuss various techniques that have been adopted to develop software tools based on this algorithm
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