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Orientation angle rotatability of planar serial n-link manipulators

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Science China(Technological Sciences) 2010年第6期53卷 1620-1637页

作者： LI RuiQin1,XIAO DengHong1 & DAI Jian S2 1 College of Mechanical Engineering and Automation,North University of China,Taiyuan 030051,China 2 Department of Mechanical Engineering,King’s College London,University of London,London WC2R 2LS,UK 1. College of Mechanical Engineering and Automation North University of China Taiyuan 030051 China2. Department of Mechanical Engineering King’s College London University of London London WC2R 2LS UK

This paper presents a new method of analyzing the orientation angle rotatability of a planar serial n-link manipulator by examining the rotatability of its virtual equivalent *** orientation boundary region decomposition is proposed based on the polynomial discriminant derived from a serial three-link *** angle workspace indicates a set of angle ranges by which the end-effector can reach with certain orientation for every point in the reachable position *** introducing a virtual equivalent mechanism,the open-chain kinematic problem is converted into a close-chain mechanism,and the Grashof-type condition is used to examine the rotatability of the end-effector *** reachable position workspace can be divided into several Grashof intervals and non-Grashof intervals based on the extreme positions and singular configurations of a *** derived equations in this paper can be used to calculate the variation rule of the orientation angle workspace of any given planar serial n-link manipulator on the basis of its link *** orientation angle rotatability of a seven-link serial manipulator is solved by the proposed method and graphical representations of the orientation angle workspaces are mapped onto a three-dimensional coordinate *** theoretical approach has practical significance for the design of a highly dexterous serial n-link manipulator with proposed link relations.

关键词： Grashof criterion planar serial manipulator orientation angle workspace virtual equivalent mechanism

Testing serial Correlation in Partially Linear Additive Models

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Acta Mathematicae Applicatae Sinica 2019年第2期35卷 401-411页

作者： Jin YANG Chuan-hua WEI School of Statistics and Data Science Nankai University Department of Applied Mathematics The Hong Kong Polytechnic University Department of Statistics School of ScienceMinzu University of China

As an extension of partially linear models and additive models, partially linear additive model is useful in statistical modelling. This paper proposes an empirical likelihood based approach for testing serial correlation in this semiparametric model. The proposed test method can test not only zero first-order serial correlation, but also higher-order serial correlation. Under the null hypothesis of no serial correlation, the test statistic is shown to follow asymptotically a chi-square distribution. Furthermore, a simulation study is conducted to illustrate the performance of the proposed method.

关键词： Partially linear additive model Backfitting Profile least-squares approach Empirical likelihood serial correlation

Planar serial Manipulator Motion Synthesis

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Journal of Harbin Institute of Technology(New Series) 2015年第2期22卷 49-55页

作者： Yanhui Wei Han Han Zepeng Wang Xin Liu Guangchun Li College of Automation Harbin Engineering University

： This paper deals with the universal serial manipulator on the inverse kinematics problem of plane type, the fast working space solution method, and the obstacle avoidance path planning method. With the vector projection as the main constraint condition of the target, it proposes a general form of the inverse kinematics solution which does not depend on the robot configuration of freedom degree. By identifying the target vector direction maximum and minimum workspace boundary and determining the destination vector by thick search on the workspaee boundary method, an expressing method of the polar coordinate form of work space is then introduced. Finally, according to the form of plane trajectory planning for obstacle avoidance problem, the method of solving the inverse kinematics solution of the concave and convex forms of the safe obstacle avoidance area is improved. The simulation results verify that the proposed method has feasibility and generality.

关键词： planar serial manipulators inverse kinematics workspace trajectory planning vector projection

Orientation angle workspaces of planar serial three-link manipulators

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Science China(Technological Sciences) 2009年第4期52卷 975-985页

作者： DAI Jian S Department of Mechanical Engineering King’s College London University of LondonWC2R 2LS United Kingdom

This paper presents a classification on the workspaces of planar serial three-link manipulators, that is, position workspace and orientation angle workspace. Position workspace indicates the region reached by the reference point on the end-effector. Orientation angle workspace indicates a set of angle ranges by which the end-effector can reach with certain orientation for every point in the reachable position workspace. By introducing a virtual equivalent mechanism, reachable position workspace can be di- vided into several Grashof intervals and non-Grashof intervals. The calculation equations of orientation angle workspace are deduced in three situations according to the relationships among four link lengths in the virtual four-bar chain. Three examples are given for three kinds of relationship of link lengths. The orientation angle workspace of extended groups, that is, two of the three link lengths equal, and the orientation angle workspace when the reference point on the end-effector moves along a non-radial direction are also discussed. A program is developed to calculate orientation angle workspaces and output variation curves of orientation angle workspace and key data within the position workspace. The approach and program in this paper can be used for fast calculation and identification of the variation rule of the orientation angle workspace of any given planar serial three-link manipulator on the basis of its link parameters, and for the design of a highly dexterous serial manipulator with proposed link rela- tions.

关键词： planar serial manipulator orientation angle workspace virtual equivalent mechanism Grashof criterion

serial nuclear transfer improves the development of interspecies reconstructed giant panda (Aluropoda melanoleucd) embryos

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Chinese Science Bulletin 2002年第6期47卷 467-469页

作者： LI Jinsong CHEN Dayuan HAN Zhiming ZHU Ziyu WEN Duancheng SUN Qingyuan LIU Zhonghua WANG Minkang LIAN Li DU Jun WANG Pengyan ZHANG Hemin State Key Laboratory of Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijing 100080China College of Animal Science and Veterinary Medicine Yangzhou UniversityYangzhou 225009China College of Life Science Beijing Normal UniversityBeijing 100857China Suzhou University Suzhou 215151China Northeast Agriculture University Harbin 150030China Yunnan University Kunming 650223China China Research and Conservation Center for Giant Panda Wolong Nature ReserveWenchuan 623006China

Interspecies somatic nuclear transfer (NT) may provide a new approach for preservation of the endangered rare species. Previous interspecies cloning studies have shown that a nucleus from a quiescent somatic cell supports early development of reconstructed embryos in the ooplasm from another species. In this study, we transferred nonqui-escent somatic cells from a giant panda into the perivitelline space of the enucleated rabbit oocytes. After electrofusion (at the rate of 71.6%) and electrical activation, 4.2% of the panda-rabbit reconstructed embryos developed to blastocyst in vitro. For improving the development rate of reconstructed embryos, we used serial NT in this study, i.e. blas-tomeres from reconstructed morulae were transferred into the perivitelline space of the enucleated rabbit oocytes. The fusion rates in the groups of serial I, serial Ⅱ and serial Ⅲ were 79.5%, 84.1% and 78.0%, respectively, having no difference with that of somatic group. And the blastocyst rates in serial NT groups

关键词： nonquiescent cell giant panda rabbit interspecies nu-clear transfer serial nuclear transfer.

The Hall Algebra of Cyclic serial Algebra

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Science China Mathematics 1994年第7期37卷 789-801页

作者：郭晋云 Department of Mathematics Hunan Normal University Changsha 410081 PRC

In this paper, orders <1 and <2 on ((Z)+)nm are introduced and also regarded as orders on the isomorphism classes of finite modules of finite .cyclic algebra R with n simple modules and all the indecomposable projecti... 详细信息

In this paper, orders serial algebra is identified with its Loewy subalgebra, and its rational extension has a basis of BPW type, and is a (((Z)+)nm, <2) filtered ring with the associated graded ring as an iterated skew polynomial ring. These results are also generalized to the Hall algebra of a tube over a finite field.

关键词： Hall algebra cyclic serial algebra filtered ring iterated skew polynomial ring.

Sex differences in color discrimination and serial reversal learning in mollies and guppies

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Current Zoology 2019年第3期65卷 323-332页

作者： Theodora FUSS Klaudia WITTE Research Group of Ecology and Behavioral Biology Institute of Biology Department of Chemistry and Biology University of Siegen Adolf-Reichwein-Str. 2 57076 Siegen Germany

Behavioral flexibility provides an individual with the ability to adapt its behavior in response to environmental changes. Studies on mammals, birds, and teleosts indicate greater behavioral flexibility in females. Conversely, males appear to exhibit greater behavioral persistenee. We, therefore, investigated sex differences in behavioral flexibility in 2 closely related molly species (Poecilia latipinna, P. mexicana) and their more distant relative, the guppy P. reticulata by comparing male and female individuals in a serial, visual reversal learning task. Fish were first trained in color discrimination, which was quickly learned by all females (guppies and mollies) and all molly males alike. Despite continued training over more than 72 sessions, male guppies did not learn the general test procedure and were, therefore, excluded from further testing. Once the reward contingency was reversed serially, molly males of both species performed considerably better by inhibiting their previous response and reached the learning criterion sign讦icantly faster than their respective con specific females. Moreover, Atlantic molly males clearly outperformed all other individuals (males and females) and some of them even reached the level of 1-trial learning. Thus, the apparently un iversal pattern of higher female behavioral flexibility seems to be in verted in the 2 examined molly species, although the evolutionary account of this pattern remains highly speculative. These findings were complemented by the observed lower neophobia of female sailfin mollies compared with their male con specifics. This sex differe nee was not observed in Atlantic mollies that were observed to be sigrdficantly less distressed in a novel situation than their consexuals. Hypothetically, sex differences in behavioral flexibility can possibly be explained in terms of the different roles that males and females play in mating competition, mate choice, and reproduction or, more gen erally, in complex socia

关键词： behavioural and cognitive flexibility colour discrimination neophobia serial reversal learning/Poecilia mexicana and Poecilia latipinna Poecilia reticulata

A new quantitative method in analysing the experiments on short term serial memory

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Science China(Technological Sciences) 1998年第5期41卷 460-464页

作者：唐孝威陈湘川张达人 1. Center for Brain Science University of Science and Technology of China 230026 Hefei China 2. Institute of High Energy Physics Chinese Academy of Sciences 100039 Beijing China 3. Biology Department University of Science and Technology of China 230026 Hefei China

A new quantitative method is introduced into the analysis of the experiments on short term serial memory (STSM). In this method, three parameters are defined to quantitatively represent the performance of memory for item and time order information. These parameters are the divergence, the disorder and the similarity. This method is used in analysing the experiments on visuo-spatial STSM. The results show that the parameters may reflect some characteristics of STSM.

关键词： short term serial memory item and time order information method of quantitative analysis.

CP embedding agent and its application to the serial section of the body wall tissue of insects

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Chinese Science Bulletin 1999年第11期44卷 1021-1024页

作者： Xuexiang Bao Yiping Zheng Hengshan Zhang Yingzhe Xia Chuantao Song NE Normal Univ Sch Life Sci Changchun 130024 Peoples R China

The key of tissue section technique is the selection and application of the embedding agent. Based on the specific characteristics of the tissue and outer skeleton of insects, a new kind of embedding agent, colophony and paraffin (CP), was used without destroying the integrity of insect organs. The tissue can be sliced continuously by the use of CP embedding technique. It solves the 3 difficult problems in the serial section of the organ and tissue of insect, namely stiff materials, thin section and continuity of sections. These difficult problems are not solved by any unitary tissue section technique that is used now, including the paraffin section technique. By using the CP embedding technique, any parts or organs (like antenna, leg and wing) and even the whole body of insects (mini body) can be sliced up continuously. It will open up wide possibilities for the study of inner structure, the interrelations among organs, the micro-characteristics and the physiological functions of insects

关键词： CP embedding agent insect body wall tissue serial section.