5,019 research outputs found

    Supporting adaptiveness of cyber-physical processes through action-based formalisms

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    Cyber Physical Processes (CPPs) refer to a new generation of business processes enacted in many application environments (e.g., emergency management, smart manufacturing, etc.), in which the presence of Internet-of-Things devices and embedded ICT systems (e.g., smartphones, sensors, actuators) strongly influences the coordination of the real-world entities (e.g., humans, robots, etc.) inhabitating such environments. A Process Management System (PMS) employed for executing CPPs is required to automatically adapt its running processes to anomalous situations and exogenous events by minimising any human intervention. In this paper, we tackle this issue by introducing an approach and an adaptive Cognitive PMS, called SmartPM, which combines process execution monitoring, unanticipated exception detection and automated resolution strategies leveraging on three well-established action-based formalisms developed for reasoning about actions in Artificial Intelligence (AI), including the situation calculus, IndiGolog and automated planning. Interestingly, the use of SmartPM does not require any expertise of the internal working of the AI tools involved in the system

    Addendum to Informatics for Health 2017: Advancing both science and practice

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    This article presents presentation and poster abstracts that were mistakenly omitted from the original publication

    Lazy State Determination for SQL databases

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    Transactional systems have seen various efforts to increase their throughput, mainly by making use of parallelism and efficient Concurrency Control techniques. Most approaches optimize the systems’ behaviour when under high contention. In this work, we strive towards reducing the system’s overall contention through Lazy State Determination (LSD). LSD is a new transactional API that leverages on futures to delay the accesses to the Database as much as possible, reducing the amount of time that transactions require to operate under isolation and, thus, reducing the contention window. LSD was shown to be a promising solution for Key-Value Stores. Now, our focus turns to Relational Database Management Systems, as we attempt to implement and evaluate LSD in this new setting. This implementation was done through a custom JDBC driver to minimize required modifications to any external platform. Results show that the reduction of the contention window effectively improves the success rate of transactional applications. However, our current implementation exhibits some performance issues that must be further investigated and addressed.Os sistemas transacionais têm sido alvo de esforços variados para aumentar a sua velocidade de processamento, principalmente através de paralelismo e de técnicas de controlo de concorrência mais eficazes. A maior parte das soluções propostas visam a otimização do comportamento destes sistemas em ambientes de elevada contenção. Neste trabalho, nós iremos reduzir a contenção no sistema recorrendo ao Lazy State Determination (LSD). O LSD é uma nova API transacional que promove a utilização de futuros para adiar o máximo os acessos à Base de Dados, reduzindo assim o tempo que cada transação requer para executar em isolamento e, por consequência, reduzindo também a janela de contenção. O LSD tem-se mostrado uma solução promissora para bases de dados Chave-Valor. O nosso foco foi agora redirecionado para Sistemas de Gestão de Bases de Dados Relacionais, com uma tentativa de implementação e avaliação do LSD neste novo contexto. Este objetivo foi concretizado através da implementação de um controlador JDBC para minimizar quaisquer alterações a plataformas externas. Os resultados mostram que a redução da janela de contenção efetivamente melhora a taxa de sucesso de aplicações transacionais. No entanto, a nossa implementação atual tem alguns problemas de desempenho que necessitam de ser investigados e endereçados

    Cost-Based Optimization of Integration Flows

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    Integration flows are increasingly used to specify and execute data-intensive integration tasks between heterogeneous systems and applications. There are many different application areas such as real-time ETL and data synchronization between operational systems. For the reasons of an increasing amount of data, highly distributed IT infrastructures, and high requirements for data consistency and up-to-dateness of query results, many instances of integration flows are executed over time. Due to this high load and blocking synchronous source systems, the performance of the central integration platform is crucial for an IT infrastructure. To tackle these high performance requirements, we introduce the concept of cost-based optimization of imperative integration flows that relies on incremental statistics maintenance and inter-instance plan re-optimization. As a foundation, we introduce the concept of periodical re-optimization including novel cost-based optimization techniques that are tailor-made for integration flows. Furthermore, we refine the periodical re-optimization to on-demand re-optimization in order to overcome the problems of many unnecessary re-optimization steps and adaptation delays, where we miss optimization opportunities. This approach ensures low optimization overhead and fast workload adaptation

    Improving construction design : The lean thinking paradigm

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    A study has been conducted into improving construction design through the application of the lean thinking paradigm. Its objective was to identify the issues relating to design efficiency and how a lean thinking approach might address these issues. The investigation consisted of examining work already undertaken in the field by other researchers"to identify the state of the art. The change order request system was examined to gain first insights into waste in construction design, and to gauge the size of the opportunity for the application of lean thinking. An Electronic Data Gathering Tool (EDGT) was then developed to allow further exploration of the design decision making process at the system / sub-system level. The EDGT was used on three live construction projects. From the data recorded a design planning tool, Design Decision Planner (DDP), was created to help improve control of the design process and lead to a more standardised approach to construction design. Standardising the approach to product development is an important component of lean thinking. The main recommendations for making construction design lean are: Use DDP to plan and improve control of the design decision making process, assign design responsibility and to make the process more transparent. 2. Measuring progress against planned design is a useful process metric. 3. Improve the designer's cost and programme visibility when choosing between design options. 4. Redefine the role of the quantity surveyor from cost controller to value for money assessor. The role needs to be better integrated into the design process to reach its full potential. 5. Need to develop more rigorous methods of assessing the buildability of design options. This problem could be eased in the short-term by incorporating construction professionals into the early design phases. 6. Designers need to use more process reason drivers when choosing between design options, not just functional criteria. 7. The change order request system could be redesigned to identify the root causes of contract issue design changes and, hence, improve the design decision making process

    Smart Manufacturing

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    This book is a collection of 11 articles that are published in the corresponding Machines Special Issue “Smart Manufacturing”. It represents the quality, breadth and depth of the most updated study in smart manufacturing (SM); in particular, digital technologies are deployed to enhance system smartness by (1) empowering physical resources in production, (2) utilizing virtual and dynamic assets over the Internet to expand system capabilities, (3) supporting data-driven decision-making activities at various domains and levels of businesses, or (4) reconfiguring systems to adapt to changes and uncertainties. System smartness can be evaluated by one or a combination of performance metrics such as degree of automation, cost-effectiveness, leanness, robustness, flexibility, adaptability, sustainability, and resilience. This book features, firstly, the concepts digital triad (DT-II) and Internet of digital triad things (IoDTT), proposed to deal with the complexity, dynamics, and scalability of complex systems simultaneously. This book also features a comprehensive survey of the applications of digital technologies in space instruments; a systematic literature search method is used to investigate the impact of product design and innovation on the development of space instruments. In addition, the survey provides important information and critical considerations for using cutting edge digital technologies in designing and manufacturing space instruments

    A gentle transition from Java programming to Web Services using XML-RPC

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    Exposing students to leading edge vocational areas of relevance such as Web Services can be difficult. We show a lightweight approach by embedding a key component of Web Services within a Level 3 BSc module in Distributed Computing. We present a ready to use collection of lecture slides and student activities based on XML-RPC. In addition we show that this material addresses the central topics in the context of web services as identified by Draganova (2003)

    Accelerated Data Delivery Architecture

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    This paper introduces the Accelerated Data Delivery Architecture (ADDA). ADDA establishes a framework to distribute transactional data and control consistency to achieve fast access to data, distributed scalability and non-blocking concurrency control by using a clean declarative interface. It is designed to be used with web-based business applications. This framework uses a combination of traditional Relational Database Management System (RDBMS) combined with a distributed Not Only SQL (NoSQL) database and a browser-based database. It uses a single physical and conceptual database schema designed for a standard RDBMS driven application. The design allows the architect to assign consistency levels to entities which determine the storage location and query methodology. The implementation of these levels is flexible and requires no database schema changes in order to change the level of an entity. Also, a data leasing system to enforce concurrency control in a non-blocking manner is employed for critical data items. The system also ensures that all data is available for query from the RDBMS server. This means that the system can have the performance advantages of a DDBMS system and the ACID qualities of a single-site RDBMS system without the complex design considerations of traditional DDBMS systems
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