905 resultados para P2P and networked data management
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Large amounts of information can be overwhelming and costly to process, especially when transmitting data over a network. A typical modern Geographical Information System (GIS) brings all types of data together based on the geographic component of the data and provides simple point-and-click query capabilities as well as complex analysis tools. Querying a Geographical Information System, however, can be prohibitively expensive due to the large amounts of data which may need to be processed. Since the use of GIS technology has grown dramatically in the past few years, there is now a need more than ever, to provide users with the fastest and least expensive query capabilities, especially since an approximated 80 % of data stored in corporate databases has a geographical component. However, not every application requires the same, high quality data for its processing. In this paper we address the issues of reducing the cost and response time of GIS queries by preaggregating data by compromising the data accuracy and precision. We present computational issues in generation of multi-level resolutions of spatial data and show that the problem of finding the best approximation for the given region and a real value function on this region, under a predictable error, in general is "NP-complete.
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Proceedings of the 11th Australasian Remote Sensing and Photogrammetry Conference
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The Internet of Things (IoT) consists of a worldwide “network of networks,” composed by billions of interconnected heterogeneous devices denoted as things or “Smart Objects” (SOs). Significant research efforts have been dedicated to port the experience gained in the design of the Internet to the IoT, with the goal of maximizing interoperability, using the Internet Protocol (IP) and designing specific protocols like the Constrained Application Protocol (CoAP), which have been widely accepted as drivers for the effective evolution of the IoT. This first wave of standardization can be considered successfully concluded and we can assume that communication with and between SOs is no longer an issue. At this time, to favor the widespread adoption of the IoT, it is crucial to provide mechanisms that facilitate IoT data management and the development of services enabling a real interaction with things. Several reference IoT scenarios have real-time or predictable latency requirements, dealing with billions of device collecting and sending an enormous quantity of data. These features create a new need for architectures specifically designed to handle this scenario, hear denoted as “Big Stream”. In this thesis a new Big Stream Listener-based Graph architecture is proposed. Another important step, is to build more applications around the Web model, bringing about the Web of Things (WoT). As several IoT testbeds have been focused on evaluating lower-layer communication aspects, this thesis proposes a new WoT Testbed aiming at allowing developers to work with a high level of abstraction, without worrying about low-level details. Finally, an innovative SOs-driven User Interface (UI) generation paradigm for mobile applications in heterogeneous IoT networks is proposed, to simplify interactions between users and things.
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Purpose – This paper attempts to seek answers to four questions. Two of these questions have been borrowed (but adapted) from the work of Defee et al.: RQ1. To what extent is theory used in purchasing and supply chain management (P&SCM) research? RQ2. What are the prevalent theories to be found in P&SCM research? Following on from these questions an additional question is posed: RQ3. Are theory-based papers more highly cited than papers with no theoretical foundation? Finally, drawing on the work of Harland et al., the authors have added a fourth question: RQ4. To what extent does P&SCM meet the tests of coherence, breadth and depth, and quality necessary to make it a scientific discipline? Design/methodology/approach – A systematic literature review was conducted in accordance with the model outlined by Tranfield et al. for three journals within the field of “purchasing and supply chain management”. In total 1,113 articles were reviewed. In addition a citation analysis was completed covering 806 articles in total. Findings – The headline features from the results suggest that nearly a decade-and-a-half on from its development, the field still lacks coherence. There is the absence of theory in much of the work and although theory-based articles achieved on average a higher number of citations than non-theoretical papers, there is no obvious contender as an emergent paradigm for the discipline. Furthermore, it is evident that P&SCM does not meet Fabian's test necessary to make it a scientific discipline and is still some way from being a normal science. Research limitations/implications – This study would have benefited from the analysis of further journals, however the analysis of 1,113 articles from three leading journals in the field of P&SCM was deemed sufficient in scope. In addition, a further significant line of enquiry to follow is the rigour vs relevance debate. Practical implications – This article is of interest to both an academic and practitioner audience as it highlights the use theories in P&SCM. Furthermore, this article raises a number of important questions. Should research in this area draw more heavily on theory and if so which theories are appropriate? Social implications – The broader social implications relate to the discussion of how a scientific discipline develops and builds on the work of Fabian and Amundson. Originality/value – The data set for this study is significant and builds on a number of previous literature reviews. This review is both greater in scope than previous reviews and is broader in its subject focus. In addition, the citation analysis (not previously conducted in any of the reviews) and statistical test highlights that theory-based articles are more highly cited than non-theoretically based papers. This could indicate that researchers are attempting to build on one another's work.
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Despite much anecdotal and oftentimes empirical evidence that black and ethnic minority employees do not feel integrated into organisational life and the implications of this lack of integration for their career progression, there is a dearth of research on the nature of the relationship black and ethnic minority employees have with their employing organisations. Additionally, research examining the relationship between diversity management and work outcomes has returned mixed findings. Scholars have attributed this to the lack of an empirically validated measure of workforce diversity management. Accordingly, I sought to address these gaps in the extant literature in a two-part study grounded in social exchange theory. In Study 1, I developed and validated a measure of workforce diversity management practices. Data obtained from a sample of ethnic minority employees from a cross section of organisations provided support for the validity of the scale. In Study 2, I proposed and tested a social-exchange-based model of the relationship between black and ethnic minority employees’ and their employing organisations, as well as assessed the implications of this relationship for their work outcomes. Specifically, I hypothesised: (i) perception of support for diversity, perception of overall justice, and developmental experiences (indicators of integration into organisational life) as mediators of the relationship between diversity management and social exchange with organisation; (ii) the moderating influence of diversity climate on the relationship between diversity management and these indicators of integration; and (iii) the work outcomes of social exchange with organisation defined in terms of career satisfaction, turnover intention and strain. SEM results provide support for most of the hypothesised relationships. The findings of the study contribute to the literature on workforce diversity management in a number of ways. First, the development and validation of a diversity management practice scale constitutes a first step in resolving the difficulty in operationalising and measuring the diversity management construct. Second, it explicates how and why diversity management practices influence a social exchange relationship with an employing organisation, and the implications of this relationship for the work outcomes of black and ethnic minority employees. My study’s focus on employee work outcomes is an important corrective to the predominant focus on organisational-level outcomes of diversity management. Lastly, by focusing on ethno-racial diversity my research complements the extant research on such workforce diversity indicators as age and gender.
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This paper provides a summary of the Social Media and Linked Data for Emergency Response (SMILE) workshop, co-located with the Extended Semantic Web Conference, at Montpellier, France, 2013. Following paper presentations and question answering sessions, an extensive discussion and roadmapping session was organised which involved the workshop chairs and attendees. Three main topics guided the discussion - challenges, opportunities and showstoppers. In this paper, we present our roadmap towards effectively exploiting social media and semantic web techniques for emergency response and crisis management.
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The research presented in this dissertation is comprised of several parts which jointly attain the goal of Semantic Distributed Database Management with Applications to Internet Dissemination of Environmental Data. ^ Part of the research into more effective and efficient data management has been pursued through enhancements to the Semantic Binary Object-Oriented database (Sem-ODB) such as more effective load balancing techniques for the database engine, and the use of Sem-ODB as a tool for integrating structured and unstructured heterogeneous data sources. Another part of the research in data management has pursued methods for optimizing queries in distributed databases through the intelligent use of network bandwidth; this has applications in networks that provide varying levels of Quality of Service or throughput. ^ The application of the Semantic Binary database model as a tool for relational database modeling has also been pursued. This has resulted in database applications that are used by researchers at the Everglades National Park to store environmental data and to remotely-sensed imagery. ^ The areas of research described above have contributed to the creation TerraFly, which provides for the dissemination of geospatial data via the Internet. TerraFly research presented herein ranges from the development of TerraFly's back-end database and interfaces, through the features that are presented to the public (such as the ability to provide autopilot scripts and on-demand data about a point), to applications of TerraFly in the areas of hazard mitigation, recreation, and aviation. ^
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The 5,280 km2 Sian Ka’an Biosphere Reserve includes pristine wetlands fed by ground water from the karst aquifer of the Yucatan Peninsula, Mexico. The inflow through underground karst structures is hard to observe making it difficult to understand, quantify, and predict the wetland dynamics. Remotely sensed Synthetic Aperture Radar (SAR) amplitude and phase observations offer new opportunities to obtain information on hydrologic dynamics useful for wetland management. Backscatter amplitude of SAR data can be used to map flooding extent. Interferometric processing of the backscattered SAR phase data (InSAR) produces temporal phase-changes that can be related to relative water level changes in vegetated wetlands. We used 56 RADARSAT-1 SAR acquisitions to calculate 38 interferograms and 13 flooding maps with 24 day and 48 day time intervals covering July 2006 to March 2008. Flooding extent varied between 1,067 km2 and 2,588 km2 during the study period, and main water input was seen to take place in sloughs during October–December. We propose that main water input areas are associated with water-filled faults that transport ground water from the catchment to the wetlands. InSAR and Landsat data revealed local-scale water divides and surface water flow directions within the wetlands.
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Background Diabetes has reached epidemic proportions in the United States, particularly among minorities, and if improperly managed can lead to medical complications and death. Healthcare providers play vital roles in communicating standards of care, which include guidance on diabetes self-management. The background of the client may play a role in the patient-provider communication process. The aim of this study was to determine the association between medical advice and diabetes self care management behaviors for a nationally representative sample of adults with diabetes. Moreover, we sought to establish whether or not race/ethnicity was a modifier for reported medical advice received and diabetes self-management behaviors. Methods We analyzed data from 654 adults aged 21 years and over with diagnosed diabetes [130 Mexican-Americans; 224 Black non-Hispanics; and, 300 White non-Hispanics] and an additional 161 with 'undiagnosed diabetes' [N = 815(171 MA, 281 BNH and 364 WNH)] who participated in the National Health and Nutrition Examination Survey (NHANES) 2007-2008. Logistic regression models were used to evaluate whether medical advice to engage in particular self-management behaviors (reduce fat or calories, increase physical activity or exercise, and control or lose weight) predicted actually engaging in the particular behavior and whether the impact of medical advice on engaging in the behavior differed by race/ethnicity. Additional analyses examined whether these relationships were maintained when other factors potentially related to engaging in diabetes self management such as participants' diabetes education, sociodemographics and physical characteristics were controlled. Sample weights were used to account for the complex sample design. Results Although medical advice to the patient is considered a standard of care for diabetes, approximately one-third of the sample reported not receiving dietary, weight management, or physical activity self-management advice. Participants who reported being given medical advice for each specific diabetes self-management behaviors were 4-8 times more likely to report performing the corresponding behaviors, independent of race. These results supported the ecological model with certain caveats. Conclusions Providing standard medical advice appears to lead to diabetes self-management behaviors as reported by adults across the United States. Moreover, it does not appear that race/ethnicity influenced reporting performance of the standard diabetes self-management behavior. Longitudinal studies evaluating patient-provider communication, medical advice and diabetes self-management behaviors are needed to clarify our findings.
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Background: Diabetes has reached epidemic proportions in the United States, particularly among minorities, and if improperly managed can lead to medical complications and death. Healthcare providers play vital roles in communicating standards of care, which include guidance on diabetes self-management. The background of the client may play a role in the patient-provider communication process. The aim of this study was to determine the association between medical advice and diabetes self care management behaviors for a nationally representative sample of adults with diabetes. Moreover, we sought to establish whether or not race/ethnicity was a modifier for reported medical advice received and diabetes self-management behaviors. Methods: We analyzed data from 654 adults aged 21 years and over with diagnosed diabetes [130 MexicanAmericans; 224 Black non-Hispanics; and, 300 White non-Hispanics] and an additional 161 with ‘undiagnosed diabetes’ [N = 815(171 MA, 281 BNH and 364 WNH)] who participated in the National Health and Nutrition Examination Survey (NHANES) 2007-2008. Logistic regression models were used to evaluate whether medical advice to engage in particular self-management behaviors (reduce fat or calories, increase physical activity or exercise, and control or lose weight) predicted actually engaging in the particular behavior and whether the impact of medical advice on engaging in the behavior differed by race/ethnicity. Additional analyses examined whether these relationships were maintained when other factors potentially related to engaging in diabetes self management such as participants’ diabetes education, sociodemographics and physical characteristics were controlled. Sample weights were used to account for the complex sample design. Results: Although medical advice to the patient is considered a standard of care for diabetes, approximately onethird of the sample reported not receiving dietary, weight management, or physical activity self-management advice. Participants who reported being given medical advice for each specific diabetes self-management behaviors were 4-8 times more likely to report performing the corresponding behaviors, independent of race. These results supported the ecological model with certain caveats. Conclusions: Providing standard medical advice appears to lead to diabetes self-management behaviors as reported by adults across the United States. Moreover, it does not appear that race/ethnicity influenced reporting performance of the standard diabetes self-management behavior. Longitudinal studies evaluating patient-provider communication, medical advice and diabetes self-management behaviors are needed to clarify our findings.
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Purpose – The purpose of this paper is to explore the links between various characteristics of hospital administration and the utilization of classes of volunteer resource management (VRM) practices. Design/methodology/approach – This paper uses original data collected via surveys of volunteer directors in 122 hospitals in five Northeastern and Southern US states. Findings – Structural equation modeling results suggest that number of paid volunteer management staff, scope of responsibility of the primary volunteer administrator, and hospital size are positively associated with increased usage of certain VRM practices. Research limitations/implications – First, the authors begin the exploration of VRM antecedents, and encourage others to continue this line of inquiry; and second, the authors assess dimensionality of practices, allowing future researchers to consider whether specific dimensions have a differential impact on key individual and organizational outcomes. Practical implications – Based on the findings of a relationship between administrative characteristics and the on-the-ground execution of VRM practice, a baseline audit comparing current practices to those VRM practices presented here might be useful in determining what next steps may be taken to focus investments in VRM that can ultimately drive practice utilization. Originality/value – The exploration of the dimensionality of volunteer management adds a novel perspective to both the academic study, and practice, of volunteer management. To the authors’ knowledge, this is the first empirical categorization of VRM practices.
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Since 2005, harmonized catch assessment surveys (CASs) have been implemented on Lake Victoria in the three riparian countries Uganda, Kenya, and Tanzania to monitor the commercial fish stocks and provide their management advice. The regionally harmonized standard operating procedures for CASs have not been wholly followed due to logistical difficulties. Yet the new approaches adopted have not been documented. This study investigated the alternative approaches used to estimate fish catches on the lake with the aim of determining the most reliable one for providing management advice and also the effect of current sampling routine on the precision of catch estimates provided. The study found the currently used lake-wide approach less reliable and more biased in providing catch estimates compared to the district based approach. Noticeable differences were detected in catch estimates between different months of the year. The study recommends future analyses of CAS data collected on the lake to follow the district based approach. Future CASs should also consider seasonal variations in the sampling design by providing for replication of sampling. The SOPs need updating to document the procedures that deviate from the original sampling design.
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Operational approaches have been more and more widely developed and used for providing marine data and information services for different socio-economic sectors of the Blue Growth and to advance knowledge about the marine environment. The objective of operational oceanographic research is to develop and improve the efficiency, timeliness, robustness and product quality of this approach. This white paper aims to address key scientific challenges and research priorities for the development of operational oceanography in Europe for the next 5-10 years. Knowledge gaps and deficiencies are identified in relation to common scientific challenges in four EuroGOOS knowledge areas: European Ocean Observations, Modelling and Forecasting Technology, Coastal Operational Oceanography and Operational Ecology. The areas "European Ocean Observations" and "Modelling and Forecasting Technology" focus on the further advancement of the basic instruments and capacities for European operational oceanography, while "Coastal Operational Oceanography" and "Operational Ecology" aim at developing new operational approaches for the corresponding knowledge areas.