Due to the correlation and diversity of robotic kinematic dexterity indexes, the principal component analysis （PCA） and kernel principal component analysis （KPCA） based on linear dimension reduction and nonlinear ...Due to the correlation and diversity of robotic kinematic dexterity indexes, the principal component analysis （PCA） and kernel principal component analysis （KPCA） based on linear dimension reduction and nonlinear dimension reduction principle could be respectively introduced into comprehensive kinematic dexterity performance evaluation of space 3R robot of different tasks. By comparing different dimension reduction effects, the KPCA method could deal more effectively with the nonlinear relationship among different single kinematic dexterity indexes, and its calculation result is more reasonable for containing more comprehensive information. KPCA＇ s calculation provides scientific basis for optimum order of robotic tasks, and furthermore a new optimization method for robotic task selection is proposed based on various performance indexes.展开更多
The recent spring up of the antineoplastic agents and the prolonged survival bring both challenge and chance to radiological practice.Radiological methods including CT,MRI and PET play an increasingly important role i...The recent spring up of the antineoplastic agents and the prolonged survival bring both challenge and chance to radiological practice.Radiological methods including CT,MRI and PET play an increasingly important role in evaluating the efficacy of these antineoplastic drugs.However,different antineoplastic agents potentially induce different radiological signs,making it a challenge for radiological response evaluation,which depends mainly on one-sided morphological response evaluation criteria in solid tumors(RECIST)in the status quo of clinical practice.This brings opportunities for the development of radiomics,which is promising to serve as a surrogate for response evaluations of anti-tumor treatments.In this article,we introduce the basic concepts of radiomics,review the state-of-art radiomics researches with highlights of radiomics application in predictions of molecular biomarkers,treatment response,and prognosis.We also provide in-depth analyses on major obstacles and future direction of this new technique in clinical investigations on new antineoplastic agents.展开更多
DC distribution networks are often employed in isolated power systems like in marine and aeronautical applications. An interesting alternative to DC machines for the supply of DC grids is constituted by a three-phase ...DC distribution networks are often employed in isolated power systems like in marine and aeronautical applications. An interesting alternative to DC machines for the supply of DC grids is constituted by a three-phase alternator feeding an AC/DC rectifier. In this paper, alternative solutions are investigated where the AC alternator is equipped with more （iV） three-phase windings and feeds the DC load through more （N） cascade-connected rectifiers. The advantages of this solution with respect to the conventional three-phase topology are highlighted along with their dependence on the number （N） of the alternator windings. For this purpose, test results are reported and discussed on a prototype generator whose stator coils can be differently connected to obtained one, two, three or four windings. The major benefits （in terms of DC output current quality and field current ripple） are found when passing from the three-phase solution to the dual winding topology; conversely, relatively little advantage is gained by increasing the number of stator windings above two.展开更多
基金Supported by the National Natural Science Foundation of China(No.51075005)the Beijing City Science and Technology Project(No.Z131100005313009)
文摘Due to the correlation and diversity of robotic kinematic dexterity indexes, the principal component analysis （PCA） and kernel principal component analysis （KPCA） based on linear dimension reduction and nonlinear dimension reduction principle could be respectively introduced into comprehensive kinematic dexterity performance evaluation of space 3R robot of different tasks. By comparing different dimension reduction effects, the KPCA method could deal more effectively with the nonlinear relationship among different single kinematic dexterity indexes, and its calculation result is more reasonable for containing more comprehensive information. KPCA＇ s calculation provides scientific basis for optimum order of robotic tasks, and furthermore a new optimization method for robotic task selection is proposed based on various performance indexes.
文摘The recent spring up of the antineoplastic agents and the prolonged survival bring both challenge and chance to radiological practice.Radiological methods including CT,MRI and PET play an increasingly important role in evaluating the efficacy of these antineoplastic drugs.However,different antineoplastic agents potentially induce different radiological signs,making it a challenge for radiological response evaluation,which depends mainly on one-sided morphological response evaluation criteria in solid tumors(RECIST)in the status quo of clinical practice.This brings opportunities for the development of radiomics,which is promising to serve as a surrogate for response evaluations of anti-tumor treatments.In this article,we introduce the basic concepts of radiomics,review the state-of-art radiomics researches with highlights of radiomics application in predictions of molecular biomarkers,treatment response,and prognosis.We also provide in-depth analyses on major obstacles and future direction of this new technique in clinical investigations on new antineoplastic agents.
文摘DC distribution networks are often employed in isolated power systems like in marine and aeronautical applications. An interesting alternative to DC machines for the supply of DC grids is constituted by a three-phase alternator feeding an AC/DC rectifier. In this paper, alternative solutions are investigated where the AC alternator is equipped with more （iV） three-phase windings and feeds the DC load through more （N） cascade-connected rectifiers. The advantages of this solution with respect to the conventional three-phase topology are highlighted along with their dependence on the number （N） of the alternator windings. For this purpose, test results are reported and discussed on a prototype generator whose stator coils can be differently connected to obtained one, two, three or four windings. The major benefits （in terms of DC output current quality and field current ripple） are found when passing from the three-phase solution to the dual winding topology; conversely, relatively little advantage is gained by increasing the number of stator windings above two.
