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Griet De Backer Marc Vantorre Peter Frigaard Charlotte Beels Julien De Rouck 《Journal of Marine Science and Technology》2010,15(2):119-130
Oscillating point absorber buoys may rise out of the water and be subjected to bottom slamming upon re-entering the water.
Numerical simulations are performed to estimate the power absorption, the impact velocities and the corresponding slamming
forces for various slamming constraints. Three buoy shapes are considered: a hemisphere and two conical shapes with deadrise
angles of 30° and 45°, with a waterline diameter of 5 m. The simulations indicate that the risk of rising out of the water
is largely dependent on the buoy draft and sea state. Although associated with power losses, emergence occurrence probabilities
can be significantly reduced by adapting the control parameters. The magnitude of the slamming load is severely influenced
by the buoy shape. The ratio between the peak impact load on the hemisphere and that on the 45° cone is approximately 2, whereas
the power absorption is only 4–8% higher for the 45° cone. This work illustrates the need to include slamming considerations
aside from power absorption criteria in the buoy shape design process and the control strategy. 相似文献
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This paper examines the relationship between a respondent's estimate of a traffic-related occurrence and his/her level of annoyance with it. Factors such as traffic flow, speeding, parked cars, standard of the sidewalk, and cyclists on the sidewalk are tested. The data was collected in 2008 from a questionnaire study sent to circa 1400 residents living along four arterial streets in Malmö, Sweden. The results indicate that the respondents seem to associate the estimate of occurrence with a rather corresponding or lower level of annoyance. Deviations from these main results are mainly found for the oldest (> 64) age group where high estimate of occurrence is associated with low annoyance concerning some of the factors. 相似文献
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Sarah Harper Charlotte Grubb Margot Stiles Ussif Rashid Sumaila 《Coastal management》2017,45(2):91-106
The contribution by women to fisheries economies globally continues to be overlooked, in part, because “fishing” is often narrowly defined as catching fish at sea, from a vessel, using specialized gears. Both men and women are involved in fisheries, but often in different roles and activities. Fisheries research, management, and policy have traditionally focused on direct, formal, and paid fishing activities—that are often dominated by men, ignoring those that are indirect, informal, and/or unpaid—where women are concentrated. This has led to a situation where men's and women's contributions to fisheries are not equally valued or even recognized and has resulted in women being largely excluded from fisheries decision-making processes. Here, we examine the contributions by women in the fisheries sector of five globally significant marine fishing countries—Mexico, Peru, Senegal, South Africa, and Vietnam. These countries each have strong links between livelihoods and marine capture fisheries, yet represent different geographic, socioeconomic, and governance contexts. Through a synthesis of existing data, case studies, and consultation with local experts, we found that the contribution by women to the fisheries of these five countries is substantial. However, this investigation also revealed major gaps in understanding of gender inequalities in the fisheries sector and the need for better gender-disaggregated data to inform fisheries policy. 相似文献
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