170 research outputs found

    Control versus Data Flow in Parallel Database Machines

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    The execution of a query in a parallel database machine can be controlled in either a control flow way, or in a data flow way. In the former case a single system node controls the entire query execution. In the latter case the processes that execute the query, although possibly running on different nodes of the system, trigger each other. Lately, many database research projects focus on data flow control since it should enhance response times and throughput. The authors study control versus data flow with regard to controlling the execution of database queries. An analytical model is used to compare control and data flow in order to gain insights into the question which mechanism is better under which circumstances. Also, some systems using data flow techniques are described, and the authors investigate to which degree they are really data flow. The results show that for particular types of queries data flow is very attractive, since it reduces the number of control messages and balances these messages over the node

    An Evaluation of Physical Disk I/Os for Complex Object Processing

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    In order to obtain the performance required for nonstandard database environments, a hierarchical complex object model with object references is used as a storage structure for complex objects. Several storage models for these complex objects, as well as a benchmark to evaluate their performance, are described. A cost model for analytical performance evaluation is developed, and the analytical results are validated by means of measurements on the DASDBS, complex object storage system. The results show which storage structures for complex objects are the most efficient under which circumstance

    Persuasive Ways to Change Entrance Use of Buildings

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    People tend to use the same door every time they enter and exit a building. When certain entrances are widely preferred over others, congestion can occur. This paper describes two interventions to persuade visitors to use another entrance. The first intervention used sensory deprivation (darkness), and the second used guidance paths. The first intervention on sensory deprivation had the expected outcome. This intervention resulted in an avoidance of the darkened door. The second intervention had a result contrary to the expectations; it resulted in an increased preference for the door without guidance paths

    Complex Object Joins in a Distributed Database

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    Preface

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    AimThis was a one-year follow-up of families referred to support services after the parents visited the emergency department due to intimate partner violence, substance abuse or a suicide attempt. Its aim was to evaluate the well-being of any children. MethodsData on families identified a year earlier by the Amsterdam protocol were gathered from child protective services and parent and child self-reports in two Dutch regions from 2012-2015. ResultsWe included 399 children (52%) boys with a median age of eight years (range 1-18) in the study using child protective services data. Of the 101 families who participated in the first measurement, 67 responded one year after the parent's emergency department visit. The results showed that 20% of the children had no or minor problems, voluntary support services were involved in 60% of cases and child protective services were involved in 20%. Compared to their first assessment a year earlier, the children's psychosocial problems had not increased, but this could have been an underestimation due to selective responses. ConclusionThe Amsterdam protocol was valuable in referring families to voluntary support services, but given the ongoing problems in some families, professionals need to carefully monitor whether support services are sufficiently effectiv

    Emerging Industrial Internet of Things Open-Source Platforms and Applications in Diverse Sectors

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    Revolutionary advances in technology have been seen in many industries, with the IIoT being a prime example. The IIoT creates a network of interconnected devices, allowing smooth communication and interoperability in industrial settings. This not only boosts efficiency, productivity, and safety but also provides transformative solutions for various sectors. This research looks into open-source IIoT and edge platforms that are applicable to a range of applications with the aim of finding and developing high-potential solutions. It highlights the effect of open-source IIoT and edge computing platforms on traditional IIoT applications, showing how these platforms make development and deployment processes easier. Popular open-source IIoT platforms include DeviceHive and Thingsboard, while EdgeX Foundry is a key platform for edge computing, allowing IIoT applications to be deployed closer to data sources, thus reducing latency and conserving bandwidth. This study seeks to identify potential future domains for the implementation of IIoT solutions using these open-source platforms. Additionally, each sector is evaluated based on various criteria, such as development requirement analyses, market demand projections, the examination of leading companies and emerging startups in each domain, and the application of the International Patent Classification (IPC) scheme for in-depth sector analysis.</p

    Increasing Performance of Professional Soccer Players and Elite Track and Field Athletes with Peak Performance Training and Biofeedback:A Pilot Study

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    The aim of this pilot study was to investigate the effects of an intervention consisting of mental coaching combined with either electro encephalogram (EEG) alpha power feedback or heart rate variability (HRV) feedback on HRV, EEG outcomes and self-reported factors related to stress, performance, recovery and sleep quality in elite athletes. A prospective pilot study was performed with two distinct cohorts. Soccer players were provided with four sessions of mental coaching combined with daily HRV biofeedback (Group A); track and field athletes were provided with four sessions of mental coaching in combination with daily neurofeedback (Group B). Measurements were performed at baseline, post intervention and at 5 weeks follow-up. Objective measures: EEG and ECG. Subjective measures: Numeric Rating Scale for performance, Pittsburgh Sleep Quality Index, Rest and Stress Questionnaire and Sports Improvement-60. Group characteristics were too distinct to compare the interventions. Linear mixed models were used to analyze differences within groups over time. In Group A, significant changes over time were present in alpha power at 5 of 7 EEG locations (p <0.01-0.03). LF/HF ratio significantly increased (p = 0.02) and the concentration (p = 0.02) and emotional scale (p = 0.03) of the SIM-60 increased significantly (p = 0.04). In Group B, the HRV low frequency power and recovery scale of the REST-Q significantly increased (p = 0.02 and <0.01 resp.). Other measures remained stable or improved non-significantly. A mental coaching program combined with either HRV or EEG alpha power feedback may increase HRV and alpha power and may lead to better performance-related outcomes and stress reduction. Further research is needed to elucidate the effects of either type of feedback and to compare effects with a control group
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