Current Issue : April - June Volume : 2019 Issue Number : 2 Articles : 5 Articles
In production processes, many adjustment tasks have to be carried out manually. In order\nto automate these activities, there is a need for cost and space efficient actuators that can provide\ncomparatively high forces. This paper presents a novel actuator concept based on the phase\nchange material paraffin wax. Furthermore, a numerical modelling strategy is introduced enabling\nthe prediction of actuator properties. The model considers paraffin wax as a deformable body.\nThe temperature-dependent volume expansion data of the paraffin wax is obtained experimentally to\nallow for a realistic description of the thermal-mechanical properties. The simulation is verified, using\nexperimental data from actuators with varying paraffin wax volumes. With a maximum deviation of\n6%, the simulations show a good agreement with the experiments....
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Electro-Mechanical Actuators (EMA) have attracted growing attention with their increasing\nincorporation in More Electric Aircraft. The performance degradation assessment of EMA needs to be\nstudied, in which EMA motor voltage is an essential parameter, to ensure its reliability and safety of\nEMA. However, deviation exists between motor voltage monitoring data and real motor voltage due\nto electromagnetic interference. To reduce the deviation, EMA motor voltage estimation generally\nrequires an accurate voltage state equation which is difficult to obtain due to the complexity of EMA.\nTo address this problem, a Feature-aided Kalman Filter (FAKF) method is proposed, in which the\nstate equation is substituted by a physical model of current and voltage. Consequently, voltage state\ndata can be obtained through current monitoring data and a currentâ??voltage model. Furthermore,\nvoltage estimation can be implemented by utilizing voltage state data and voltage monitoring data.\nTo validate the effectiveness of the FAKF-based estimation method, experiments have been conducted\nbased on the published data set from NASAâ??s Flyable Electro-Mechanical Actuator (FLEA) test stand.\nThe experiment results demonstrate that the proposed method has good performance in EMA motor\nvoltage estimation....
Located on the mountainous area, Kelok Sembilan flyover area in West Sumatra,\nIndonesia has a long history of land deformation, therefore monitoring\nand analyzing as continuously is a necessity to minimize the impact.\nNotably, in the rainy season, the land deformation occurs along this area. The\nzone is crucial as the center of transportation connection in the middle of\nSumatra. Quasi-Persistent Scatterer (Q-PS) Interferometry technique was applied\nfor extracting information of land deformation on the field from time to\ntime. Not only does the method have high performance for detecting land\ndeformation but also improve the number of PS point, especially in a\nnon-urban area. This research supported by 90 scenes of Sentinel-1A\n(C-band) taken from October 2014 to November 2017 for ascending and\ndescending orbit with VV and VH polarization in 5 Ã? 20 m (range Ã? azimuth)\nresolution. Both satellite orbits detected two critical locations of land\ndeformation namely as zone A and Zone B, which located in positive steep\nslope where there is more than 500 mm movement in the Line of Sight (LOS)\nduring acquisition time. Deformations in the vertical and horizontal direction\nfor both zone, are 778.9 mm, 795.7 mm and 730.5 mm, 751.7 mm, respectively.\nFinally, the results were confirmed by ground truth data using Unmanned\nAerial Vehicle (UAV) observation....
This study aims to assess ecological effects of the construction of marine\nranching in the eastern Guangdong waters. Variations in sea surface temperature\n(SST), chlorophyll a concentration (Chl-a), catch per unit effort\n(CPUE), biodiversity, biomass and density of benthos were compared during\nthe pre- (August in 2011) and post- (August in 2013) marine ranching. These\nwere based on satellite remote sensing and survey data. Results showed that\nthe ratio of Nitrogen (N): Phosphorus (P) was closed to 16, Chl-a increased���....
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