420 research outputs found

    A review of the healthcare-management (modeling) literature published at Manufacturing and Service Operations Management

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    Healthcare systems throughout the world are under pressure to widen access, improve efficiency and quality of care, and reduce inequity. Achieving these conflicting goals requires innovative approaches, utilizing new technologies, data analytics, and process improvements. The operations management community has taken on this challenge: more than 10% of articles published in M&SOM in the period from 2009 to 2018 has developed analytical models that aim to inform healthcare operational decisions and improve medical decision-making. This article presents a review of the research published in M&SOM on healthcare management since its inception 20 years ago and reflects on opportunities for further research

    Managing Water under Uncertainty and Risk: The United Nations World Water Development Report 4

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    This report introduces new aspects of water issues: 1) it reintroduces the 12 challenge area reports that provided the foundation for the first two World Water Development Reports (WWDR); 2) 4 new reports on water quality, groundwater, gender, and desertification, land degradation and drought; 3) in recognition that the global challenges of water can vary considerably across countries and regions, a series of 5 regional reports have been included; 4) a deeper analysis of the main external forces of freshwater resources and possibilities for their future evolution; 5) managing water under uncertainty and risk

    Resource discovery for distributed computing systems: A comprehensive survey

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    Large-scale distributed computing environments provide a vast amount of heterogeneous computing resources from different sources for resource sharing and distributed computing. Discovering appropriate resources in such environments is a challenge which involves several different subjects. In this paper, we provide an investigation on the current state of resource discovery protocols, mechanisms, and platforms for large-scale distributed environments, focusing on the design aspects. We classify all related aspects, general steps, and requirements to construct a novel resource discovery solution in three categories consisting of structures, methods, and issues. Accordingly, we review the literature, analyzing various aspects for each category

    A survey of flooding, gossip routing, and related schemes for wireless multi- hop networks

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    Flooding is an essential and critical service in computer networks that is used by many routing protocols to send packets from a source to all nodes in the network. As the packets are forwarded once by each receiving node, many copies of the same packet traverse the network which leads to high redundancy and unnecessary usage of the sparse capacity of the transmission medium. Gossip routing is a well-known approach to improve the flooding in wireless multi-hop networks. Each node has a forwarding probability p that is either statically per-configured or determined by information that is available at runtime, e.g, the node degree. When a packet is received, the node selects a random number r. If the number r is below p, the packet is forwarded and otherwise, in the most simple gossip routing protocol, dropped. With this approach the redundancy can be reduced while at the same time the reachability is preserved if the value of the parameter p (and others) is chosen with consideration of the network topology. This technical report gives an overview of the relevant publications in the research domain of gossip routing and gives an insight in the improvements that can be achieved. We discuss the simulation setups and results of gossip routing protocols as well as further improved flooding schemes. The three most important metrics in this application domain are elaborated: reachability, redundancy, and management overhead. The published studies used simulation environments for their research and thus the assumptions, models, and parameters of the simulations are discussed and the feasibility of an application for real world wireless networks are highlighted. Wireless mesh networks based on IEEE 802.11 are the focus of this survey but publications about other network types and technologies are also included. As percolation theory, epidemiological models, and delay tolerant networks are often referred as foundation, inspiration, or application of gossip routing in wireless networks, a brief introduction to each research domain is included and the applicability of the particular models for the gossip routing is discussed

    Descoberta de recursos para sistemas de escala arbitrarias

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    Doutoramento em InformĂĄticaTecnologias de Computação DistribuĂ­da em larga escala tais como Cloud, Grid, Cluster e Supercomputadores HPC estĂŁo a evoluir juntamente com a emergĂȘncia revolucionĂĄria de modelos de mĂșltiplos nĂșcleos (por exemplo: GPU, CPUs num Ășnico die, Supercomputadores em single die, Supercomputadores em chip, etc) e avanços significativos em redes e soluçÔes de interligação. No futuro, nĂłs de computação com milhares de nĂșcleos podem ser ligados entre si para formar uma Ășnica unidade de computação transparente que esconde das aplicaçÔes a complexidade e a natureza distribuĂ­da desses sistemas com mĂșltiplos nĂșcleos. A fim de beneficiar de forma eficiente de todos os potenciais recursos nesses ambientes de computação em grande escala com mĂșltiplos nĂșcleos ativos, a descoberta de recursos Ă© um elemento crucial para explorar ao mĂĄximo as capacidade de todos os recursos heterogĂ©neos distribuĂ­dos, atravĂ©s do reconhecimento preciso e localização desses recursos no sistema. A descoberta eficiente e escalĂĄvel de recursos ÂŽe um desafio para tais sistemas futuros, onde os recursos e as infira-estruturas de computação e comunicação subjacentes sĂŁo altamente dinĂąmicas, hierarquizadas e heterogĂ©neas. Nesta tese, investigamos o problema da descoberta de recursos no que diz respeito aos requisitos gerais da escalabilidade arbitrĂĄria de ambientes de computação futuros com mĂșltiplos nĂșcleos ativos. A principal contribuição desta tese ÂŽe a proposta de uma entidade de descoberta de recursos adaptativa hĂ­brida (Hybrid Adaptive Resource Discovery - HARD), uma abordagem de descoberta de recursos eficiente e altamente escalĂĄvel, construĂ­da sobre uma sobreposição hierĂĄrquica virtual baseada na auto-organizaçãoo e auto-adaptação de recursos de processamento no sistema, onde os recursos computacionais sĂŁo organizados em hierarquias distribuĂ­das de acordo com uma proposta de modelo de descriçãoo de recursos multi-camadas hierĂĄrquicas. Operacionalmente, em cada camada, que consiste numa arquitetura ponto-a-ponto de mĂłdulos que, interagindo uns com os outros, fornecem uma visĂŁo global da disponibilidade de recursos num ambiente distribuĂ­do grande, dinĂąmico e heterogĂ©neo. O modelo de descoberta de recursos proposto fornece a adaptabilidade e flexibilidade para executar consultas complexas atravĂ©s do apoio a um conjunto de caracterĂ­sticas significativas (tais como multi-dimensional, variedade e consulta agregada) apoiadas por uma correspondĂȘncia exata e parcial, tanto para o conteĂșdo de objetos estĂ©ticos e dinĂąmicos. SimulaçÔes mostram que o HARD pode ser aplicado a escalas arbitrĂĄrias de dinamismo, tanto em termos de complexidade como de escala, posicionando esta proposta como uma arquitetura adequada para sistemas futuros de mĂșltiplos nĂșcleos. TambĂ©m contribuĂ­mos com a proposta de um regime de gestĂŁo eficiente dos recursos para sistemas futuros que podem utilizar recursos distribuĂ­os de forma eficiente e de uma forma totalmente descentralizada. AlĂ©m disso, aproveitando componentes de descoberta (RR-RPs) permite que a nossa plataforma de gestĂŁo de recursos encontre e aloque dinamicamente recursos disponĂ­eis que garantam os parĂąmetros de QoS pedidos.Large scale distributed computing technologies such as Cloud, Grid, Cluster and HPC supercomputers are progressing along with the revolutionary emergence of many-core designs (e.g. GPU, CPUs on single die, supercomputers on chip, etc.) and significant advances in networking and interconnect solutions. In future, computing nodes with thousands of cores may be connected together to form a single transparent computing unit which hides from applications the complexity and distributed nature of these many core systems. In order to efficiently benefit from all the potential resources in such large scale many-core-enabled computing environments, resource discovery is the vital building block to maximally exploit the capabilities of all distributed heterogeneous resources through precisely recognizing and locating those resources in the system. The efficient and scalable resource discovery is challenging for such future systems where the resources and the underlying computation and communication infrastructures are highly-dynamic, highly-hierarchical and highly-heterogeneous. In this thesis, we investigate the problem of resource discovery with respect to the general requirements of arbitrary scale future many-core-enabled computing environments. The main contribution of this thesis is to propose Hybrid Adaptive Resource Discovery (HARD), a novel efficient and highly scalable resource-discovery approach which is built upon a virtual hierarchical overlay based on self-organization and self-adaptation of processing resources in the system, where the computing resources are organized into distributed hierarchies according to a proposed hierarchical multi-layered resource description model. Operationally, at each layer, it consists of a peer-to-peer architecture of modules that, by interacting with each other, provide a global view of the resource availability in a large, dynamic and heterogeneous distributed environment. The proposed resource discovery model provides the adaptability and flexibility to perform complex querying by supporting a set of significant querying features (such as multi-dimensional, range and aggregate querying) while supporting exact and partial matching, both for static and dynamic object contents. The simulation shows that HARD can be applied to arbitrary scales of dynamicity, both in terms of complexity and of scale, positioning this proposal as a proper architecture for future many-core systems. We also contributed to propose a novel resource management scheme for future systems which efficiently can utilize distributed resources in a fully decentralized fashion. Moreover, leveraging discovery components (RR-RPs) enables our resource management platform to dynamically find and allocate available resources that guarantee the QoS parameters on demand

    Management, Technology and Learning for Individuals, Organisations and Society in Turbulent Environments

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    This book presents the collection of fifty two papers which were presented on the First International Conference on BUSINESS SUSTAINABILITY ’08 - Management, Technology and Learning for Individuals, Organisations and Society in Turbulent Environments, held in Ofir, Portugal, from 25th to 27th of June, 2008. The main motive of the meeting was the growing awareness of the importance of the sustainability issue. This importance had emerged from the growing uncertainty of the market behaviour that leads to the characterization of the market, i.e. environment, as turbulent. Actually, the characterization of the environment as uncertain and turbulent reflects the fact that the traditional technocratic and/or socio-technical approaches cannot effectively and efficiently lead with the present situation. In other words, the rise of the sustainability issue means the quest for new instruments to deal with uncertainty and/or turbulence. The sustainability issue has a complex nature and solutions are sought in a wide range of domains and instruments to achieve and manage it. The domains range from environmental sustainability (referring to natural environment) through organisational and business sustainability towards social sustainability. Concerning the instruments for sustainability, they range from traditional engineering and management methodologies towards “soft” instruments such as knowledge, learning, creativity. The papers in this book address virtually whole sustainability problems space in a greater or lesser extent. However, although the uncertainty and/or turbulence, or in other words the dynamic properties, come from coupling of management, technology, learning, individuals, organisations and society, meaning that everything is at the same time effect and cause, we wanted to put the emphasis on business with the intention to address primarily the companies and their businesses. From this reason, the main title of the book is “Business Sustainability” but with the approach of coupling Management, Technology and Learning for individuals, organisations and society in Turbulent Environments. Concerning the First International Conference on BUSINESS SUSTAINABILITY, its particularity was that it had served primarily as a learning environment in which the papers published in this book were the ground for further individual and collective growth in understanding and perception of sustainability and capacity for building new instruments for business sustainability. In that respect, the methodology of the conference work was basically dialogical, meaning promoting dialog on the papers, but also including formal paper presentations. In this way, the conference presented a rich space for satisfying different authors’ and participants’ needs. Additionally, promoting the widest and global learning environment and participativeness, the Conference Organisation provided the broadcasting over Internet of the Conference sessions, dialogical and formal presentations, for all authors’ and participants’ institutions, as an innovative Conference feature. In these terms, this book could also be understood as a complementary instrument to the Conference authors’ and participants’, but also to the wider readerships’ interested in the sustainability issues. The book brought together 97 authors from 10 countries, namely from Australia, Finland, France, Germany, Ireland, Portugal, Russia, Serbia, Sweden and United Kingdom. The authors “ranged” from senior and renowned scientists to young researchers providing a rich and learning environment. At the end, the editors hope and would like that this book will be useful, meeting the expectation of the authors and wider readership and serving for enhancing the individual and collective learning, and to incentive further scientific development and creation of new papers. Also, the editors would use this opportunity to announce the intention to continue with new editions of the conference and subsequent editions of accompanying books on the subject of BUSINESS SUSTAINABILITY, the second of which is planned for year 2011.info:eu-repo/semantics/publishedVersio

    Emerging Informatics

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    The book on emerging informatics brings together the new concepts and applications that will help define and outline problem solving methods and features in designing business and human systems. It covers international aspects of information systems design in which many relevant technologies are introduced for the welfare of human and business systems. This initiative can be viewed as an emergent area of informatics that helps better conceptualise and design new world-class solutions. The book provides four flexible sections that accommodate total of fourteen chapters. The section specifies learning contexts in emerging fields. Each chapter presents a clear basis through the problem conception and its applicable technological solutions. I hope this will help further exploration of knowledge in the informatics discipline
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