112 research outputs found
Технологии и техника наноуровня
В пособии рассмотрено содержание основных видов учебных занятий по курсу "Технологии и техника наноуровня", а также контрольных мер по изучению дисциплины. Приведены задания контрольных работ и методика их выполнения для студентов заочной и дистанционной форм обучения. Предназначено для студентов специальности "Прикладная механика" дневной, заочной и дистанционной форм обучения, в том числе для иностранных студентов
Stochastic Reconstruction and Interpolation of Precipitation Fields Using Combined Information of Commercial Microwave Links and Rain Gauges
For the reconstruction and interpolation of precipitation fields, we present the application of a stochastic approach called Random Mixing. Generated fields are based on a data set consisting of rain gauge observations and path-averaged rain rates estimated using Commercial Microwave Link (CML) derived information. Precipitation fields are received as linear combination of unconditional spatial random fields, where the spatial dependence structure is described by copulas. The weights of the linear combination are optimized such that the observations and the spatial structure of the precipitation observations are reproduced. The innovation of the approach is that this strategy enables the simulation of ensembles of precipitation fields of any size. Each ensemble member is in concordance with the observed path-averaged CML derived rain rates and additionally reflects the observed rainfall variability along the CML paths. The ensemble spread allows additionally an estimation of the uncertainty of the reconstructed precipitation fields. The method is demonstrated both for a synthetic data set and a real-world data set in South Germany. While the synthetic example allows an evaluation against a known reference, the second example demonstrates the applicability for real-world observations. Generated precipitation fields of both examples reproduce the spatial precipitation pattern in good quality. A performance evaluation of Random Mixing compared to Ordinary Kriging demonstrates an improvement of the reconstruction of the observed spatial variability. Random Mixing is concluded to be a beneficial new approach for the provision of precipitation fields and ensembles of them, in particular when different measurement types are combined
Wave-train induced unpinning of weakly anchored vortices in excitable media
A free vortex in excitable media can be displaced and removed by a
wave-train. However, simple physical arguments suggest that vortices anchored
to large inexcitable obstacles cannot be removed similarly. We show that
unpinning of vortices attached to obstacles smaller than the core radius of the
free vortex is possible through pacing. The wave-train frequency necessary for
unpinning increases with the obstacle size and we present a geometric
explanation of this dependence. Our model-independent results suggest that
decreasing excitability of the medium can facilitate pacing-induced removal of
vortices in cardiac tissue.Comment: Published versio
TO ERADICATION OF VOLTAGE SAG AND HARMONICS IN DISTRIBUTION SYSTEM USING DVR WITH CAPACITOR COMPENSATION SCHEME
Power Quality (PQ) is that the most vital perspectives on transmission and distribution ranges. The availability of high-grade electric powered offerings wished for the customers illustrates this idea. The voltage sag and swell square degree the most not unusual PQ problems that in particular rise up in the distribution systems because of the truth that it's going to cause tool tripping, failure of stress systems, closure for home and business instrumentality. The Dynamic Voltage Restorer (DVR) associated nonparallel has amazing dynamic talents and is a flexible solution for PQ troubles. Ultra-capacitors (UCAP) have quality developments like excessive strength and espresso electricity density important for the mitigation of voltage sag and swell. This paper offers AN extended DVR topology capable of handing over deep, prolonged mitigation for power terrific troubles. Within the planned DVR, UCAP is employed as strength storage because it offers immoderate electricity in a totally short c software language length of it gradual. The DVR is protected into Ultra capacitor via a bifacial DC-DC converter which facilitates in supplying a rigid dc-link voltage and conjointly enables in compensating transient voltage sag and voltage swell. PI Controller is hired in DVR for electricity exceptional improvement. The simulation model for the proposed device has been superior in MATLAB and therefore the performance over famous DVR is legitimate with the effects obtained
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