1,568 research outputs found

    Using Hybrid Angle/Distance Information for Distributed Topology Control in Vehicular Sensor Networks

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    In a vehicular sensor network (VSN), the key design issue is how to organize vehicles effectively, such that the local network topology can be stabilized quickly. In this work, each vehicle with on-board sensors can be considered as a local controller associated with a group of communication members. In order to balance the load among the nodes and govern the local topology change, a group formation scheme using localized criteria is implemented. The proposed distributed topology control method focuses on reducing the rate of group member change and avoiding the unnecessary information exchange. Two major phases are sequentially applied to choose the group members of each vehicle using hybrid angle/distance information. The operation of Phase I is based on the concept of the cone-based method, which can select the desired vehicles quickly. Afterwards, the proposed time-slot method is further applied to stabilize the network topology. Given the network structure in Phase I, a routing scheme is presented in Phase II. The network behaviors are explored through simulation and analysis in a variety of scenarios. The results show that the proposed mechanism is a scalable and effective control framework for VSNs

    A SMIL-Based Catalog Presentation System in Electronic Commerce

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    Web-based catalog presentations play the key-enabling role in E-commerce in recent years. Existing catalog systems often acquire proprietary platforms, cannot deal with TV-like media objects, or consume network bandwidth inefficiently. With the emergence of advanced technologies of Web and multimedia, such hurdles can be removed. The Synchronized Multimedia Integration Language (SMIL), proposed by W3C allows Web designers to design complicated and vivid multimedia presentations in a declarative manner. These presentations are then rendered on a general-purpose browser by a SMIL player. Since the SMIL specification is quite new to the Internet and E-commerce societies, the functionality and applications of players is limited. In this paper, we propose a novel architecture based on Java JMF technology for tackling with such constraints. The effectiveness of the proposed system is validated through an experiment on product catalog presentations

    Assessing the Integrity of Spillway Foundations

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    The erosion under a spillway can be a long-term issue that threatens the structural integrity of a water reservoir. The spillway under investigation was suspected to be defective after it had been commissioned in 1987 (Figure 1). Potholes and subsurface cavities were confirmed in the safety assessment using various NDT techniques including ground penetrating radar and impact echo. The GPR inspection was able to differentiate the intact region from the cavities under concrete slabs (Figure 2). The impact echo results and associated analyses provided further evidence of inferior condition in the soil under the concrete slabs. The engineering team designed and executed the repair project based on the conclusion of the integrity assessment. Subsequent GPR inspection has been performed so as to monitor the integrity of the spillway in a period of 18 months following the repair

    Antiobiotics stewardship for Laparoscopic cholecystectomy

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    A novel regulatory event-based gene set analysis method for exploring global functional changes in heterogeneous genomic data sets

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    <p>Abstract</p> <p>Background</p> <p>Analyzing gene expression data by assessing the significance of pre-defined gene sets, rather than individual genes, has become a main approach in microarray data analysis and this has promisingly derive new biological interpretations of microarray data. However, the detection power of conventional gene list or gene set-based approaches is limited on highly heterogeneous samples, such as tumors.</p> <p>Results</p> <p>We developed a novel method, the regulatory <b>e</b>vent-based <b>G</b>ene <b>S</b>et <b>A</b>nalysis (eGSA), which considers not only the consistently changed genes but also every gene regulation (event) of each sample to overcome the detection limit. In comparison with conventional methods, eGSA can detect functional changes in heterogeneous samples more precisely and robustly. Furthermore, by utilizing eGSA, we successfully revealed novel functional characteristics and potential mechanisms of very early hepatocellular carcinoma (HCC).</p> <p>Conclusion</p> <p>Our study creates a novel scheme to directly target the major cellular functional changes in heterogeneous samples. All potential regulatory routines of a functional change can be further analyzed by the regulatory event frequency. We also provide a case study on early HCCs and reveal a novel insight at the initial stage of hepatocarcinogenesis. eGSA therefore accelerates and refines the interpretation of heterogeneous genomic data sets in the absence of gene-phenotype correlations.</p

    Understanding Mobile Apps Continuance Usage Behavior and Habit: An Expectance-Confirmation Theory

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    With the growing development of information technology and the wireless telecommunication network nowadays, mobile devices have been expanding rapidly and have been emerging as important tools for consumers. Using m-services and applications (apps) on mobile devices becomes custom in people’s daily lives. This study proposes a theoretical model to explore the continued usage behavior for smartphone. The objective of this study is to explore how perceived usefulness, perceived enjoyment, and confirmation influencing satisfaction and habit of consumers, and in turn influencing continued usage behavior, as well as the moderating effect of three characteristics of m-commerce. The proposed model will empirically be tested using survey method and collecting data from smartphone users in longitudinal setting. The structural equation modeling technique will be used to evaluate the causal model and confirmatory factor analysis will be performed to examine the reliability and validity of the measurement model. The findings of this study are expected to illustrate how factors influence individuals to use m-services and mobile apps and become a habit, as well as how these habits influence continued smartphone usage

    Surgical experience of adult primary hepatic sarcomas

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    Using Linear Regression to Identify Critical Demographic Variables Affecting Patient Safety Culture From Viewpoints of Physicians and Nurses

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    Background: The issues of patient safety and healthcare quality have become increasingly important around the world since the 1990s. Many hospitals manage to reduce the number of adverse events (AEs) that can threaten patient safety in healthcare organizations. Assessing the existing patient safety culture gives hospital management a clear vision of an organization’s strengths and weaknesses. The Safety Attitudes Questionnaire, with its good psychometric properties and great internal consistency, has been used extensively to assess the patient safety culture in healthcare organizations.Objective: Physicians and nurses form the core staff of each organization. With different demographic variables, they might perceive patient safety culture differently. This study purposed to identify critical demographic variables from the viewpoints of physicians and nurses that significantly influence the patient safety culture in a regional teaching hospital in Taiwan.Methods: Linear regression with forward selection was employed in this study to focus on all physicians and nurses using results of a 2015 internal survey in the case hospital. Ten demographic variables were the independent variables, and seven dimensions of the Chinese version of the Safety Attitudes Questionnaire were dependent variables.Results: Four out of 10 demographic variables had significant impacts on 6 out of 7 dimensions (with the exception of emotional exhaustion) from the Safety Attitudes Questionnaire. “Supervisor/manager” and “experience in position” followed by “age” were viewed by physicians and nurses as the most critical variables affecting the patient safety culture in this regional teaching hospital in Taiwan.Conclusion: Assessing an organization’s current patient safety culture provides a significant value to improving patient safety. This study revealed that “supervisor/manager” and “experience in position” are the 2 most important demographic variables influencing the patient safety culture. Hospital management should take heed of the suggestions of staff members regarding these characteristics to continuously enhance their patient safety culture

    Enhancing the Performance of a Rainfall Measurement System Using Artificial Neural Networks Based Object Tracking Algorithms

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    With the recent development of optical sensing and digital image processing techniques, high-speed cameras have been applied to measure the microphysical properties of raindrops. However, the performance of such systems are significantly affected by object tracking algorithms. In order to improve the measurement accuracy of rainfall rate and accumulated rainfall, a novel object tracking algorithm based on artificial neural networks (ANN) is proposed in this paper. The ANN model takes the features of each raindrop in the two successive images as inputs including the center coordinates, area, canting angle, the lengths of long axis and minor axis of the equivalent ellipse. The output of the ANN model is the matched probabilities of each pair of raindrops between before and after images. Experimental data were collected during a real rainfall event. Performance comparisons between the traditional and ANN based object tracking algorithms are conducted based on the experimental data. Experimental results suggest the successful matching rate is significantly increased from 87.20% to 95.60% due to the usage of the ANN based algorithm. Hence, the improved disdrometer system is capable of producing more accurate and robust measurements of rainfall status
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