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Least Squares Fitting Based Fault Classification in Distribution Systems 被引量:1
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作者 Omar A. Saraereh Qais Alsafasfeh +2 位作者 Anas Al Tarabsheh Aouda Arfoa Issa Etier 《Journal of Energy and Power Engineering》 2014年第3期560-567,共8页
Power systems are the largest and most complex human made systems, consisting of thousands of electrical sources, loads, transmission and distribution lines, power transformers, circuit breakers, etc. where faults alw... Power systems are the largest and most complex human made systems, consisting of thousands of electrical sources, loads, transmission and distribution lines, power transformers, circuit breakers, etc. where faults always occurred. Faults can cause personnel and equipment safety problems, and can result in significant disruption to power supply and thus financial losses. In this paper we will present comprehensive mathematical suite to detect and classify fault dependent models of various types of power systems. This work will extract fault unique signatures by using polarization ellipse during the healthy condition and the polarization will be circular shape with radius equal the rated voltage of the system, but during the fault condition the polarization will be ellipse shape and the fault signature will be defined according the ellipse parameters major axis, minor axis, ellipticity and orientation angle, by using least squares criterion will define the ellipse parameters this system will identify and classify. This paper will be a milestone for extended paper based on the proposed mathematical modelling and applying it to identify, classify and localize with simulation model. 展开更多
关键词 Distribution systems major axis minor axis ELLIPTICITY FAULT ELLIPSE least squares criterion.
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Apple fruit size estimation using a 3D machine vision system 被引量:7
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作者 A.Gongal M.Karkee S.Amatya 《Information Processing in Agriculture》 EI 2018年第4期498-503,共6页
Estimation of fruit size in tree fruit crops is essential for selective robotic harvesting and crop-load estimation.Machine vision systems for fruit detection and localization have been studied widely for robotic harv... Estimation of fruit size in tree fruit crops is essential for selective robotic harvesting and crop-load estimation.Machine vision systems for fruit detection and localization have been studied widely for robotic harvesting and crop-load estimation.However,only a few studies have been carried out to estimate fruit size in orchards using machine vision systems.This study was carried out to develop a machine vision system consisting of a color CCD camera and a time-of-flight(TOF)light-based 3D camera for estimating apple size in tree canopies.As a measure of fruit size,the major axis(longest axis)was estimated based on(i)the 3D coordinates of pixels on corresponding apple surfaces,and(ii)the 2D size of individual pixels within apple surfaces.In the 3D coordinates-based method,the distance between pairs of pixels within apple regions were calculated using 3D coordinates,and the maximum distance between all pixel pairs within an apple region was estimated to be the major axis.The accuracy of estimating the major axis using 3D coordinates was 69.1%.In the pixel-size-based method,the physical sizes of pixels were estimated using a calibration model developed based on pixel coordinates and the distance to pixels from the camera.The major axis length was then estimated by summing the size of individual pixels along the major axis of the fruit.The accuracy of size estimation increased to 84.8%when the pixel size-based method was used.The results showed the potential for estimating fruit size in outdoor environments using a 3D machine vision system. 展开更多
关键词 Machine vision Fruit identification 3D registration Size estimation major axis
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Sexual size dimorphism in lizards:Rensch’s rule,reproductive mode,clutch size,and line fitting method effects 被引量:2
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作者 Tao LIANG Shai MEIRI Lei SHI 《Integrative Zoology》 SCIE CSCD 2022年第5期787-803,共17页
Rensch’s rule relates to a pattern whereby sexual size dimorphism is more female-biased in small-sized species and more male-biased in large-sized ones.We collected literature and museum data on the body size of male... Rensch’s rule relates to a pattern whereby sexual size dimorphism is more female-biased in small-sized species and more male-biased in large-sized ones.We collected literature and museum data on the body size of males and females belonging to 4032 lizard species,as well as data on their reproductive modes and clutch sizes.We used phylogenetic comparative analyses,and general linear mixed models,to test Rensch’s rule and examined how re-productive mode and clutch size affect sexual size dimorphism.Sexual size dimorphism was independent of clutch size in lizard species with variable clutch sizes and in oviparous lizards.Large litters were associated with female-biased sexual dimorphism in viviparous and in scincomorph lizards.Inference regarding Rensch’s rule depended on the analytical method used to identify it.The widely used,but less conservative,reduced major axis regression usually support Rensch’s rule while ordinary least squares regressions mostly show isometric relationships.The rule tended to apply more to oviparous than to viviparous lizards.We infer that Rensch’s rule is,at best,a weak pattern in lizards.This is especially true in viviparous lineages where females reproduce infrequently and therefore evolve large sizes to maximise fecundity,resulting in female-biased dimorphism. 展开更多
关键词 fecundity selection reduced major axis regression sexual selection sexual size dimorphism VIVIPARITY
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