Search results for "wind"
showing 10 items of 846 documents
Usage des organisateurs anti-entropique dans les documents électroniques : approche expérimentale des fenêtres ponctuelles
1999
International audience; Les documents électroniques permettent de nombreuses manières d'organiser, de présenter et d'accéder à l'information. Une utilisation pertinente de ces options par les auteurs requiert une bonne connaissance des effets que ces choix ont sur la représentation cognitive et les traitements faits par l'utilisateur. Cette approche des documents électroniques, sur la base du concept de représentation mentale, fournit un cadre d'analyse des structures et signaux propres à ce type d'écriture. Parmi ces signaux que nous appelons « organisateurs para-linguistiques » pour les distinguer de leurs équivalents purement textuels, un ensemble est destiné à réduire l'entropie due à l…
Intégrer des informations en escamots dans les textes techniques : quels effets sur les processus cognitifs ?
1998
Though computerized sytems now offer a wide range of options for accessing and displaying text or text-picture information, little is known about their effects on the user's cognitive processes. In this paper, we investigate the effect of a computer-specific display (pop-up window) which consists in displaying some pieces of information in windows that appear only under user's action. Experiments were carried out to compare the pop-up window device with other devices used on paper. The experiments dealt with text only as well as text-picture documents and involved various tasks. Results are discussed from a theoretical and a practical point of view.
Toward farm-level health management of wind turbine systems: status and scope for improvements
2018
An outline of health management for OWFs has been detailed in this chapter with description of various important elements. The need for such farm level management is explained and benefits are discussed. Key gaps to be filled in order to realize such a system are identified. The proposed health management system is mainly based on the existing knowledge of fleet-level management in the aerospace sector. Health management is much broader than CM; there are a number of aspects beyond the prognostics capabilities that are to be designed in order to arrive at a comprehensive maintenance management scheme. A comprehensive maintenance program that is sensitive to the health of the assets and adap…
Musculoskeletal disorders and incongruous postures in workers on ropes: A pilot study
2023
Background: Occupational hazards believed to cause musculoskeletal disorders in rope workers are traditionally associated with maintaining incongruous postures for prolonged periods of time. Design and methods: A cross-sectional survey was conducted on 132 technical operators in the wind energy and acrobatic construction sectors, who work on ropes, analysing the ergonomic characteristics of the environments, the way in which tasks are carried out, the strain perceived by individual workers, and assessing the presence of any musculoskeletal disorders (MSDs) by means of an objective examination focused on the anatomical districts that were the object of our study. Results: Analysis of the dat…
An Approach to the conversion of the power generated by an offshore wind power farm connected into seawave power generator
2011
Performance Improvement of Grid-Integrated Doubly Fed Induction Generator under Asymmetrical and Symmetrical Faults
2023
The doubly fed induction generator (DFIG)-based wind energy conversion system (WECS) suffers from voltage and frequency fluctuations due to the stochastic nature of wind speed as well as nonlinear loads. Moreover, the high penetration of wind energy into the power grid is a challenge for its smooth operation. Hence, symmetrical faults are most intense, inflicting the stator winding to low voltage, disturbing the low-voltage ride-through (LVRT) functionality of a DFIG. The vector control strategy with proportional–integral (PI) controllers was used to control rotor-side converter (RSC) and grid-side converter (GSC) parameters. During a symmetrical fault, however, a series grid-side converter…
Servera uzstādīšana nelielam birojam
2015
Šī darba mērķis ir nelielam birojam izveidot serverus ar dažādām lomām ar virtuālo mašīnu palīdzību. Servera pamatā būs Windows Server 2012 R2 Standart. Serveriem jābūt uzstādītiem kvalitatīvi. Uz serveriem tiek uzstādīta nepieciešamā programmatūra šī biroja vajadzībām, bet šāda programmatūra var noderēt gandrīz visos parastos birojos. Darba uzdevumos arī ietilpst izveidot drošu un regulāru rezervju kopiju veidošanu. Kā arī jānodrošina tīkla drošība no dažādiem draudiem un vīrusiem, tas ir izdarāms ar pretvīrusu programmām un ugunsmūriem.
Investigating the Structure of Vela X
2018
Vela X is the prototypical example of a pulsar wind nebula whose morphology and detailed structure have been affected by the interaction with the reverse shock of its host supernova remnant. The resulting complex of filamentary structure and mixed-in ejecta embedded in a nebula that is offset from the pulsar provides the best example we have of this middle-age state that characterizes a significant fraction of composite SNRs, and perhaps all of the large-diameter PWNe seen as TeV sources. Here we report on an XMM-Newton Large Project study of Vela X, supplemented by additional Chandra observations. Through broad spectral modeling as well as detailed spectral investigations of discrete emiss…
Urban Heat Island Monitoring and Impacts on Citizen's General Health Status in Isfahan Metropolis: A Remote Sensing and Field Survey Approach.
2020
Urban heat islands (UHIs) are one of the urban management challenges, especially in metropolises, which can affect citizens’ health and well-being. This study used a combination of remote sensing techniques with field survey to investigate systematically the effects of UHI on citizens’ health in Isfahan metropolis, Iran. For this purpose, the land surface temperature (LST) over a three-year period was monitored by Landsat-8 satellite imagery based on the split window algorithm. Then, the areas where UHI and urban cold island (UCI) phenomena occurred were identified and a general health questionnaire-28 (GHQ-28) was applied to evaluate the health status of 800 citizens in terms o…
Ski jumping takeoff in a wind tunnel with skis.
2011
The effect of skis on the force–time characteristics of the simulated ski jumping takeoff was examined in a wind tunnel. Takeoff forces were recorded with a force plate installed under the tunnel floor. Signals from the front and rear parts of the force plate were collected separately to examine the anteroposterior balance of the jumpers during the takeoff. Two ski jumpers performed simulated takeoffs, first without skis in nonwind conditions and in various wind conditions. Thereafter, the same experiments were repeated with skis. The jumpers were able to perform very natural takeoff actions (similar to the actual takeoff) with skis in wind tunnel. According to the subjective feeling of the…