94 research outputs found

    From the Prospective of Ergonomics: Estimating Overall Stressors and Task Demands in the Construction Sites in Saudi Arabia Using an Analytical Hierarchy Process (AHP)

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    651-658Balancing individual capabilities with occupational demands and workplace stressors is necessary to reduce stress and prevent ergonomic and safety hazards. This is particularly true in occupations like construction that are characterized by numerous stressors, intense perceived overall demands, environmental factors, physical and mental loads, awkward postures, and organizational and personal factors in particular in Saudi Arabia. The current study proposes a subjective tool for assessing the impact of stressors on overall task demand (OTD). The analytic hierarchy process (AHP) was used to estimate the OTD and identify the factors that contribute to it. The OTD assessment tool survey participants were 524 male and was validated at actual construction worksites with 168 workers distributed among 7 jobs. The findings showed that OTD was significantly affected by occupational demands and identified a relationship among OTD, physiological measures and the NASA-TLX score. The proposed framework can help decision-makers and supervisors identify task demands, determine risk factors, and develop strategies for balancing job demands and worker capability

    Availability assessment of free-space-optics links with rain data from tropical climates

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    Rainfall in tropical environments acts as a dominant parameter for estimating the availability of free-space optics (FSO). Long fades are caused by precipitation in particular heavy rains, and this precipitation increases atmospheric attenuation due to rain and reduces the availability of optical power from FSO links. In this paper, the link availability of an FSO system is estimated under the impact of rain in a tropical climate. The influence of rain on the propagation of FSO signal is investigated based on experimental and statistical analyses of rain-rate measurements under tropical conditions. Rain-rate data are measured in Malaysia for three years and used to estimate the availability of FSO links. Models developed in Malaysia are used to predict atmospheric attenuation due to rain. Long-term statistical measurements of rain data can enable good estimation of link availability. Based on the prediction model and measured rain-rate data, the FSO link budget is analyzed, and the link availability as a function of distance is predicted. Carrier class availability limits the FSO link to a few hundred meters only, whereas enterprise class availability can exceed FSO links over a few kilometers long

    Availability analysis of terrestrial free space optical link under the impact of rain condition

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    Availability is one of the main factors to measure the QoS of any telecommunication networks. An accurate availability prediction for Free Space Optical link of carrier class grade is needed. In tropical areas, rain is the most dominant factor affecting the FSO link availability. In this paper, the effect of rain attenuation on the availability of FSO links is analyzed by examining the impact distance of different FSO systems. As the rain attenuation of FSO is independent of wavelength, the analysis of rain attenuation will be based on rain intensity. ITU-R (Carbonneau and Japan) models have been used for the analysis. From the results; Carrier class availability with good enough resolution for estimated availability can be predicted. This paper provides recommendations to FSO researchers in general and local telecom service provider in particular about possible availability figures that can be useful for deployment of FSO link as a last mile solution, back-up for fiber optic and other applications

    Современные концепции управления высшим учебным заведением

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    Целью и задачами статьи является исследование современных подходов к управлению вузом, их критический анализ и возможность оптимизации процессов деятельности вуза
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