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121.
Øystein Vedaa Anette Harris Bjørn Bjorvatn Siri Waage Børge Sivertsen Philip Tucker 《Ergonomics》2016,59(1):1-14
A systematic literature search was carried out to investigate the relationship between quick returns (i.e. 11.0 hours or less between two consecutive shifts) and outcome measures of health, sleep, functional ability and work–life balance. A total of 22 studies published in 21 articles were included. Three types of quick returns were differentiated (from evening to morning/day, night to evening, morning/day to night shifts) where sleep duration and sleepiness appeared to be differently affected depending on which shifts the quick returns occurred between. There were some indications of detrimental effects of quick returns on proximate problems (e.g. sleep, sleepiness and fatigue), although the evidence of associations with more chronic outcome measures (physical and mental health and work–life balance) was inconclusive.
Practitioner Summary: Modern societies are dependent on people working shifts. This study systematically reviews literature on the consequences of quick returns (11.0 hours or less between two shifts). Quick returns have detrimental effects on acute health problems. However, the evidence regarding effects on chronic health is inconclusive. 相似文献
122.
Theo Lynn Lisa van der Werff Graham Hunt Philip Healy 《Journal of Computer Information Systems》2016,56(3):185-193
The purpose of this research is to identify the potential information components of an online, real-time trust label, which is proposed as a communication mechanism to encourage trust in cloud service providers and cloud computing products. An online Delphi process was used with 28 cloud computing experts (including vendors, software providers, and legal and business representatives). The proposed label contains 81 information components, covering the cloud service provider (e.g. physical location, legal jurisdiction), the cloud service itself (e.g. data location, security, backup, certification), and a historical service-level summary (e.g. uptime data, support response times). The potential benefits of such a label to encourage trustworthiness perceptions and trust behaviors in the cloud computing environment are explored. Limitations of the study are highlighted, and further research studies are suggested to test the concept of the label and to refine the components of the label itself. 相似文献
123.
Precarious or temporary work is associated with adverse outcomes including low control over working hours, work-life conflict and stress. The rise in precarious employment is most marked in the service sector but little research has been done on its health effects in this sector. This study compares permanent and temporary workers in the hotel industry, where working hours are highly variable. Survey data from 150 workers from eight 3-Star hotels in urban and regional areas around Sydney were analyzed. Forty-five per cent were male and 52 per cent were female. Fifty four per cent were permanent full-time and 46 per cent were temporary workers. The effects of employment status on perceived job security, control over working hours, and work-life conflict are investigated using PLS-Graph 3.0. The effects of control over working hours, on work-life conflict and subsequent health outcomes are also explored. Temporary workers perceived themselves as less in control of their working hours, than permanent workers (β = .27). However, they also reported lower levels of work intensity (β = .25) and working hours (β = .38). The effects of low hours control (β = .20), work intensity (β = .29), and excessive hours (β = .39) on work-life conflict (r2 = .50), and subsequent health effects (r2 = .30), are illustrated in the final structural equation model. 相似文献
124.
Spatial information takes different forms in different applications, ranging from accurate coordinates in geographic information systems to the qualitative abstractions that are used in artificial intelligence and spatial cognition. As a result, existing spatial information processing techniques tend to be tailored towards one type of spatial information, and cannot readily be extended to cope with the heterogeneity of spatial information that often arises in practice. In applications such as geographic information retrieval, on the other hand, approximate boundaries of spatial regions need to be constructed, using whatever spatial information that can be obtained. Motivated by this observation, we propose a novel methodology for generating spatial scenarios that are compatible with available knowledge. By suitably discretizing space, this task is translated to a combinatorial optimization problem, which is solved using a hybridization of two well-known meta-heuristics: genetic algorithms and ant colony optimization. What results is a flexible method that can cope with both quantitative and qualitative information, and can easily be adapted to the specific needs of specific applications. Experiments with geographic data demonstrate the potential of the approach. 相似文献
125.
Steven Hancock Mathias Disney Jan-Peter Muller Philip Lewis Mike Foster 《Remote sensing of environment》2011,115(12):3286-3297
Lidars have the unique ability to make direct, physical measurements of forest height and vertical structure in much denser canopies than is possible with passive optical or short wavelength radars. However the literature reports a consistent underestimate of tree height when using physically based methods, necessitating empirical corrections. This bias is a result of overestimating the range to the canopy top due to background noise and failing to correctly identify the ground.This paper introduces a method, referred to as “noise tracking”, to avoid biases when determining the range to the canopy top. Simulated waveforms, created with Monte-Carlo ray tracing over geometrically explicit forest models, are used to test noise tracking against simple thresholding over a range of forest and system characteristics. It was found that noise tracking almost completely removed the bias in all situations except for very high noise levels and very low (< 10%) canopy covers. In all cases noise tracking gave lower errors than simple thresholding and had a lower sensitivity to the initial noise threshold.Finite laser pulses spread out the measured signal, potentially overriding the benefit of noise tracking. In the past laser pulse length has been corrected by adding half that length to the signal start range. This investigation suggests that this is not always appropriate for simple thresholding and that the results for noise tracking were more directly related to pulse length than for simple thresholding. That this effect has not been commented on before may be due to the possible confounding impacts of instrument and survey characteristics inherent in field data. This method should help improve the accuracy of waveform lidar measurements of forests, whether using airborne or spaceborne instruments. 相似文献
126.
A method for image analysis, representation and re-synthesis is introduced. Unlike other schemes it is not pixel based but rather represents a picture as vector data, from which an altered version of the original image can be rendered. Representing an image as vector data allows performing operations such as zooming, retouching or colourising, avoiding common problems associated with pixel image manipulation. This paper brings together methods from the areas of computer vision, image compositing and image based rendering to prove that this type of image representation is a step towards accurate and efficient image manipulation. 相似文献
127.
A survey of approaches to automatic schema matching 总被引:76,自引:1,他引:75
Erhard Rahm Philip A. Bernstein 《The VLDB Journal The International Journal on Very Large Data Bases》2001,10(4):334-350
Schema matching is a basic problem in many database application domains, such as data integration, E-business, data warehousing,
and semantic query processing. In current implementations, schema matching is typically performed manually, which has significant
limitations. On the other hand, previous research papers have proposed many techniques to achieve a partial automation of
the match operation for specific application domains. We present a taxonomy that covers many of these existing approaches,
and we describe the approaches in some detail. In particular, we distinguish between schema-level and instance-level, element-level
and structure-level, and language-based and constraint-based matchers. Based on our classification we review some previous
match implementations thereby indicating which part of the solution space they cover. We intend our taxonomy and review of
past work to be useful when comparing different approaches to schema matching, when developing a new match algorithm, and
when implementing a schema matching component.
Received: 5 February 2001 / Accepted: 6 September 2001 Published online: 21 November 2001 相似文献
128.
Philip J. Dobson 《Information Systems Frontiers》2001,3(2):199-210
It is argued that recent research in the information systems field has tended to either emphasise the structural/collective dimension or the agency/individual dimension, not both. Structuration theory is a more recent attempt to address both agency and structure, however there are a number of issues with the use of structuration theory in information systems research, not the least of which is its lack of recognition of the temporal and longitudinal nature of information systems development. A relatively new philosophy, critical realism, provides the potential for a new approach to social investigations in its provision of an ontology for the analytical separation of structure and agency. The philosophy is introduced and its implications for sociological investigation are discussed. 相似文献
129.
Chin‐Yang Lee Chi‐Hung Liu Chih‐Wei Chen Saodo Miki Huang‐Ming Philip Chen Shermann Lin Po‐Hua Su Chein‐Dhau Lee 《Journal of the Society for Information Display》2008,16(1):71-75
Abstract— Novel anode layer plasma within minimum chamber space was developed for non‐contact alignment process. The plasma‐treated polyimide (PI) surface showed no particle contamination and no micro‐scratches. Surface morphology was investigated by using scanning electron microscope (SEM), an atomic force microscope (AFM), and X‐ray photoemission spectroscopy. The different oxygen‐to‐carbon ratio ([O]/[C] ratio) for XPS spectra indicated a composition change after plasma treatment. Surface pretilt angles were varied from 0 to 2.1° under different plasma exposure times. Finally, a prototype 20.8‐in. QXGA IPS‐mode gray‐scale medical liquid‐crystal display was successfully demonstrated with high contrast ratio, excellent uniformity, and wide viewing angle using this new plasma‐beam‐alignment technique. 相似文献
130.
Effective on-line algorithms for reliable due date quotation and large-scale scheduling 总被引:1,自引:0,他引:1
We consider the sequencing of a series of jobs that arrive at a single processor over time. At each job’s arrival time, a
due date must be quoted for the job, and the job must complete processing before its quoted due date. The objective is to
minimize the sum (or average) of quoted due dates, or equivalently, the average quoted lead time. In this paper, we propose
on-line heuristics for this problem and characterize the conditions under which these heuristics are asymptotically optimal.
Computational testing further demonstrates the relative effectiveness of these heuristics under various conditions.
Both authors made equal contributions to this paper and are listed in alphabetical order. 相似文献