235,704 research outputs found

    PID control system analysis, design, and technology

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    Designing and tuning a proportional-integral-derivative (PID) controller appears to be conceptually intuitive, but can be hard in practice, if multiple (and often conflicting) objectives such as short transient and high stability are to be achieved. Usually, initial designs obtained by all means need to be adjusted repeatedly through computer simulations until the closed-loop system performs or compromises as desired. This stimulates the development of "intelligent" tools that can assist engineers to achieve the best overall PID control for the entire operating envelope. This development has further led to the incorporation of some advanced tuning algorithms into PID hardware modules. Corresponding to these developments, this paper presents a modern overview of functionalities and tuning methods in patents, software packages and commercial hardware modules. It is seen that many PID variants have been developed in order to improve transient performance, but standardising and modularising PID control are desired, although challenging. The inclusion of system identification and "intelligent" techniques in software based PID systems helps automate the entire design and tuning process to a useful degree. This should also assist future development of "plug-and-play" PID controllers that are widely applicable and can be set up easily and operate optimally for enhanced productivity, improved quality and reduced maintenance requirements

    Design and performance evaluation of the "iTIVA" algorithm for manual infusion of intravenous anesthetics based on effect-site target

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    Introduction: Remifentanil and propofol infusion using TCI pumps has proven to be beneficial for the practice of anesthesia but the availability of these systems is limited. Objective: Designing a pharmacokinetic model-based algorithm for calculating manual infusion regimens to achieve plasma and effect-site concentrations that may be used in volume infusion pumps, and to compare the difference between the desired and the forecasted concentrations via pharmacokinetic simulation. Methods: Using the Minto & Schnider models for remifentanil and propofol respectively, the algorithm was implemented on an iTIVA application (interactive TIVA) for iOS and Android operating systems. The performance of the algorithm was evaluated estimating the infusion regimens for achieving different effect-site concentrations for induction and maintenance in 34 theoretical patients for 240. minutes. Results: The infusion regimens obtained for remifentanil and propofol resulted in less than 5% average systemic deviation versus the target effect-site concentrations during induction and maintenance. Only one induction infusion was required for remifentanil and propofol. Just one infusion rate was required for remifentanil during maintenance, and between 2 to 5 infusion rate changes for propofol to maintain a stable concentration. The iTIVA-based algorithm estimates concentrations similar to the TivaTrainerÂź software. Conclusions: The performance of the algorithm to achieve effect-site concentrations during induction and maintenance for remifentanil and propofol was excellent, with a low systemic deviation versus the desired target concentrations

    Fine Grained Component Engineering of Adaptive Overlays: Experiences and Perspectives

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    Recent years have seen significant research being carried out into peer-to-peer (P2P) systems. This work has focused on the styles and applications of P2P computing, from grid computation to content distribution; however, little investigation has been performed into how these systems are built. Component based engineering is an approach that has seen successful deployment in the field of middleware development; functionality is encapsulated in ‘building blocks’ that can be dynamically plugged together to form complete systems. This allows efficient, flexible and adaptable systems to be built with lower overhead and development complexity. This paper presents an investigation into the potential of using component based engineering in the design and construction of peer-to-peer overlays. It is highlighted that the quality of these properties is dictated by the component architecture used to implement the system. Three reusable decomposition architectures are designed and evaluated using Chord and Pastry case studies. These demonstrate that significant improvements can be made over traditional design approaches resulting in much more reusable, (re)configurable and extensible systems

    Systematic evaluation of design choices for software development tools

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    [Abstract]: Most design and evaluation of software tools is based on the intuition and experience of the designers. Software tool designers consider themselves typical users of the tools that they build and tend to subjectively evaluate their products rather than objectively evaluate them using established usability methods. This subjective approach is inadequate if the quality of software tools is to improve and the use of more systematic methods is advocated. This paper summarises a sequence of studies that show how user interface design choices for software development tools can be evaluated using established usability engineering techniques. The techniques used included guideline review, predictive modelling and experimental studies with users

    An empirical study evaluating depth of inheritance on the maintainability of object-oriented software

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    This empirical research was undertaken as part of a multi-method programme of research to investigate unsupported claims made of object-oriented technology. A series of subject-based laboratory experiments, including an internal replication, tested the effect of inheritance depth on the maintainability of object-oriented software. Subjects were timed performing identical maintenance tasks on object-oriented software with a hierarchy of three levels of inheritance depth and equivalent object-based software with no inheritance. This was then replicated with more experienced subjects. In a second experiment of similar design, subjects were timed performing identical maintenance tasks on object-oriented software with a hierarchy of five levels of inheritance depth and the equivalent object-based software. The collected data showed that subjects maintaining object-oriented software with three levels of inheritance depth performed the maintenance tasks significantly quicker than those maintaining equivalent object-based software with no inheritance. In contrast, subjects maintaining the object-oriented software with five levels of inheritance depth took longer, on average, than the subjects maintaining the equivalent object-based software (although statistical significance was not obtained). Subjects' source code solutions and debriefing questionnaires provided some evidence suggesting subjects began to experience diffculties with the deeper inheritance hierarchy. It is not at all obvious that object-oriented software is going to be more maintainable in the long run. These findings are sufficiently important that attempts to verify the results should be made by independent researchers

    Development of the Integrated Model of the Automotive Product Quality Assessment

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    Issues on building an integrated model of the automotive product quality assessment are studied herein basing on widely applicable methods and models of the quality assessment. A conceptual model of the automotive product quality system meeting customer requirements has been developed. Typical characteristics of modern industrial production are an increase in the production dynamism that determines the product properties; a continuous increase in the volume of information required for decision-making, an increased role of knowledge and high technologies implementing absolutely new scientific and technical ideas. To solve the problem of increasing the automotive product quality, a conceptual structural and hierarchical model is offered to ensure its quality as a closed system with feedback between the regulatory, manufacturing, and information modules, responsible for formation of the product quality at all stages of its life cycle. The three module model of the system of the industrial product quality assurance is considered to be universal and to give the opportunity to explore processes of any complexity while solving theoretical and practical problems of the quality assessment and prediction for products for various purposes, including automotive

    The SPOSAD Architectural Style for Multi-tenant Software Applications

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    Keywords-Software architecture; Software quality; Software performance; Software maintenance Abstract—A multi-tenant software application is a special type of highly scalable, hosted software, in which the ap-plication and its infrastructure are shared among multiple tenants to save development and maintenance costs. The limited understanding of the underlying architectural concepts still prevents many software architects from designing such a system. Existing documentation on multi-tenant software architectures is either technology-specific or database-centric. A more technology-independent perspective is required to enable wide-spread adoption of multi-tenant architectures. We propose the SPOSAD architectural style, which describes the components, connectors, and data elements of a multi-tenant architecture as well as constraints imposed on these elements. This paper describes the benefits of a such an architecture and the trade-offs for the related design decisions. To evaluate our proposal, we illustrate how concepts of the style help to make current Platform-as-a-Service (PaaS) environments, such as Force.com, Windows Azure, and Google App Engine scalable and customizable

    Aplikasi Website Indeks Kepuasan Masyarakat (Studi Kasus: Kelurahan Panarung)

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    Service performance appraisal is now starting to become a benchmark for achieving quality service by evaluating every service and piece of information provided. The provision of questionnaire sheets is currently considered less effective in determining the satisfaction index of services due to storing data on questionnaire results and re-recording the results that have been filled in by the community. Therefore, this study aims to build a website to improve the work system with the aim of increasing the efficiency of the community satisfaction index. In designing the Community Satisfaction Index (IKM) Website, Panarung Village uses the waterfall method with stages: requirements definition, system and software design, implementation and unit testing, integration and system testing, operation and maintenance. This website has been tested with black box testing, and the results show that the features on the website can run well. The Panarung Village Community Satisfaction Index (IKM) website can be used as evaluation material for the performance of services in the Pahandut sub-district and also as a means of information such as news data, graphs, survey results, and criticism suggestions
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