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“four freedoms”到底是几大自由 被引量:1
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作者 黄粉保 《中国科技翻译》 北大核心 2010年第4期53-55,共3页
英语中有大量的一词多义现象,同一个词在上下句之间出现语义偏差也很常见。翻译时一定要紧扣上下文,仔细考证,弄清确切含义。罗斯福在二战期间所提出的所谓"Four Freedoms"国内媒体、学界都译作"四大自由"。然而,fr... 英语中有大量的一词多义现象,同一个词在上下句之间出现语义偏差也很常见。翻译时一定要紧扣上下文,仔细考证,弄清确切含义。罗斯福在二战期间所提出的所谓"Four Freedoms"国内媒体、学界都译作"四大自由"。然而,freedom一词前后意义并不一样,笼统地译作"四大自由"有名不副实之嫌。鉴于"Four Freedom s"原本是一个有机整体,如果分而译之会使译文显得支离破碎。但在翻译其具体内涵时,个中语义偏差应该得到体现。 展开更多
关键词 语义偏差 四大自由 译名 名不副实
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THE THEORY AND APPLICATION OF THE STRUCTURE LIGHT ENGINEERING SURVEYING BASED ON A LASER THEODOLITE WITH THREE FREEDOMS OF ROTATION 被引量:1
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作者 Feng Wenhao Li Xin 《Geo-Spatial Information Science》 2001年第1期28-36,共9页
The concepts of “confining structure” and structure light are illuminated in this paper.A laser theodolite with three freedoms of rotation,which is aimed at “confining structure”,is developed.Various scanning mode... The concepts of “confining structure” and structure light are illuminated in this paper.A laser theodolite with three freedoms of rotation,which is aimed at “confining structure”,is developed.Various scanning modes and their mathematical models based on laser theodolite with three freedoms of rotation are discussed.According to the features of a huge object,,the structure light engineering surveying based on laser theodolite with three freedoms of rotation is determined as the main method in an actual application.The observation of four sound concrete posts and forced centering plates.Subsequently,it is transformed into the huge object coordinate system.The scanning mode with plumb plane is selected as the main mode in the whole work.And other assistant methods,such as close range photogrammetry and the method of using reflection sheet,are applied to the work of “scanning dead angle”.At last,a surveying accuracy estimation of this method is done and a surveying accuracy test is finished.It can be concluded that the structure light engineering surveying based on laser theodolite with three freedoms of rotation is considered to be an effective and applied method,and has many superiority to some other surveying methods in the work of surveying “confining structure”. 展开更多
关键词 STRUCTURE LIGHT engineering surveying LASER THEODOLITE THREE freedoms of ROTATION
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Contradictory Freedoms? Kant on Moral Agency and Political Rights
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作者 Aaron James Wendland 《Journal of Philosophy Study》 2012年第8期538-546,共9页
This essay examines the degree to which Kant's understanding of external freedom and right are consistent with and can form a part of his moral philosophy. In doing so, this essay begins by looking at the foundation ... This essay examines the degree to which Kant's understanding of external freedom and right are consistent with and can form a part of his moral philosophy. In doing so, this essay begins by looking at the foundation and possibility of moral experience as it is presented in the Groundwork for the Metaphysics of Morals. This essay then turns to explore Kant's understanding of external freedom and right as set out in The Metaphysics of Morals and examines the apparent inconsistencies that exist between these concepts and Kant's explication of moral worth. After pointing out the distinction between right and morality, this essay goes on to argue that, strictly speaking, Kant's conception of external freedom and right cannot form part of his moral philosophy (as so defined in the Groundwork). Finally, this essay concludes by arguing that although right and morality are irreconcilable, Kant's account of external freedom and right can nevertheless serve as part of his "moral" philosophy insofar as these concepts represent Kant's attempt to externalize the moral law, or simply expand the definition of morality to cover any action that accords with the right. 展开更多
关键词 Kant freedom MORALITY RIGHT moral philosophy
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Time-Domain Analysis of Body Freedom Flutter Based on 6DOF Equation
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作者 Zhehan Ji Tongqing Guo +2 位作者 Di Zhou Zhiliang Lu Binbin Lyu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期489-508,共20页
The reduced weight and improved efficiency of modern aeronautical structures result in a decreasing separation of frequency ranges of rigid and elastic modes.Particularly,a high-aspect-ratio flexible flying wing is pr... The reduced weight and improved efficiency of modern aeronautical structures result in a decreasing separation of frequency ranges of rigid and elastic modes.Particularly,a high-aspect-ratio flexible flying wing is prone to body freedomflutter(BFF),which is a result of coupling of the rigid body short-periodmodewith 1st wing bendingmode.Accurate prediction of the BFF characteristics is helpful to reflect the attitude changes of the vehicle intuitively and design the active flutter suppression control law.Instead of using the rigid body mode,this work simulates the rigid bodymotion of the model by using the six-degree-of-freedom(6DOF)equation.A dynamicmesh generation strategy particularly suitable for BFF simulation of free flying aircraft is developed.An accurate Computational Fluid Dynamics/Computational Structural Dynamics/six-degree-of-freedom equation(CFD/CSD/6DOF)-based BFF prediction method is proposed.Firstly,the time-domain CFD/CSD method is used to calculate the static equilibrium state of the model.Based on this state,the CFD/CSD/6DOF equation is solved in time domain to evaluate the structural response of themodel.Then combinedwith the variable stiffnessmethod,the critical flutter point of the model is obtained.This method is applied to the BFF calculation of a flyingwing model.The calculation results of the BFF characteristics of the model agree well with those fromthe modalmethod andNastran software.Finally,the method is used to analyze the influence factors of BFF.The analysis results show that the flutter speed can be improved by either releasing plunge constraint or moving the center ofmass forward or increasing the pitch inertia. 展开更多
关键词 Body freedom flutter time-domain CFD/CSD/6DOF method dynamic mesh generation strategy aeroelasticity
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Triad-displaced ULAs configuration for non-circular sources with larger continuous virtual aperture and enhanced degrees of freedom
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作者 SHAIKH Abdul Hayee DANG Xiaoyu HUANG Daqing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2024年第1期81-93,共13页
Non-uniform linear array(NULA)configurations are well renowned due to their structural ability for providing increased degrees of freedom(DOF)and wider array aperture than uniform linear arrays(ULAs).These characteris... Non-uniform linear array(NULA)configurations are well renowned due to their structural ability for providing increased degrees of freedom(DOF)and wider array aperture than uniform linear arrays(ULAs).These characteristics play a significant role in improving the direction-of-arrival(DOA)estimation accuracy.However,most of the existing NULA geometries are primarily applicable to circular sources(CSs),while they limitedly improve the DOF and continuous virtual aperture for noncircular sources(NCSs).Toward this purpose,we present a triaddisplaced ULAs(Tdis-ULAs)configuration for NCS.The TdisULAs structure generally consists of three ULAs,which are appropriately placed.The proposed antenna array approach fully exploits the non-circular characteristics of the sources.Given the same number of elements,the Tdis-ULAs design achieves more DOF and larger hole-free co-array aperture than its sparse array competitors.Advantageously,the number of uniform DOF,optimal distribution of elements among the ULAs,and precise element positions are uniquely determined by the closed-form expressions.Moreover,the proposed array also produces a filled resulting co-array.Numerical simulations are conducted to show the performance advantages of the proposed Tdis-ULAs configuration over its counterpart designs. 展开更多
关键词 direction-of-arrival(DOA)estimation sparse array non-circular source(NCS) sum co-array difference co-array degrees of freedom(DOF)
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Degree of Freedom Analysis for Holographic MIMO Based on a Mutual-Coupling-Compliant Channel Model
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作者 SUN Yunqi JIAN Mengnan +2 位作者 YANG Jun ZHAO Yajun CHEN Yijian 《ZTE Communications》 2024年第1期34-40,共7页
Degree of freedom(DOF)is a key indicator for spatial multiplexing layers of a wireless channel.Traditionally,the channel of a multiple-input multiple-output(MIMO)half-wavelength dipole array has a DOF that equals the ... Degree of freedom(DOF)is a key indicator for spatial multiplexing layers of a wireless channel.Traditionally,the channel of a multiple-input multiple-output(MIMO)half-wavelength dipole array has a DOF that equals the antenna number.However,recent studies suggest that the DOF could be less than the antenna number when strong mutual coupling is considered.We utilize a mutual-coupling-compliant channel model to investigate the DOF of the holographic MIMO(HMIMO)channel and give a upper bound of the DOF with strong mutual coupling.Our numerical simulations demonstrate that a dense array can support more DOF per unit aperture as compared with a half-wavelength MIMO system. 展开更多
关键词 channel model degree of freedom holographic MIMO mutual coupling
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开源片上系统Freedom E310调试过程原理分析 被引量:1
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作者 雷思磊 王军 张海燕 《单片机与嵌入式系统应用》 2017年第9期19-22,28,共5页
Freedom E310是第一款基于RISC-V指令集架构的开源商业片上系统,可以依据具体应用场景对其进行深度定制,在介绍Freedom E310中与调试有关的模块、地址空间、控制状态寄存器之后,从原理上分析了halt、resume、step、断点设置等调试指令... Freedom E310是第一款基于RISC-V指令集架构的开源商业片上系统,可以依据具体应用场景对其进行深度定制,在介绍Freedom E310中与调试有关的模块、地址空间、控制状态寄存器之后,从原理上分析了halt、resume、step、断点设置等调试指令的实现过程。 展开更多
关键词 RISC-V freedom E310 JTAG
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开源片上系统Freedom E310调试方法研究 被引量:1
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作者 雷思磊 薛正 《单片机与嵌入式系统应用》 2017年第7期59-62,共4页
Freedom E310是第一款基于RISC—V指令集架构的开源商业片上系统,可以依据具体应用场景对其进行深度定制,在对Freedom E310及其Debug单元简单介绍的基础上,设计通过OpenOCD、J—Link建立Freedom E310调试环境,并进行了实际测试。
关键词 RISC—V freedom E310 JTAG
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六自由度步态分析系统评估膝骨关节炎严重程度的客观准确性
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作者 Shaban Amiri Nzelekela 杨连博 李澎 《中国组织工程研究》 CAS 北大核心 2025年第27期5890-5896,共7页
背景:膝骨关节炎的传统评估方法是基于患者的临床症状、体格检查和影像学表现做出判断,但是这些方法不能反映膝关节的动力学动态变化,不能多维度反映出膝关节的客观状态。六自由度步态分析系统为膝骨关节炎的严重程度提供了更加客观、... 背景:膝骨关节炎的传统评估方法是基于患者的临床症状、体格检查和影像学表现做出判断,但是这些方法不能反映膝关节的动力学动态变化,不能多维度反映出膝关节的客观状态。六自由度步态分析系统为膝骨关节炎的严重程度提供了更加客观、更为实用的一种动态评估方法,为不同患者更精准的治疗方案提供了依据,从而优化患者的治疗策略。目的:综述膝骨关节炎的相关评估系统,将六自由度步态分析与传统评估膝骨关节炎严重程度的方法进行比较,探讨六自由度步态分析在指导膝骨关节炎治疗策略制定方面的应用效果。方法:通过计算机检索Google Scholar、PubMed数据库2002年1月至2023年6月发表的相关文献,英文检索词为“knee osteoarthritis,knee osteoarthritis severity,6DOF gait analysis,evaluation methods,WOMAC,KOOS”;中文检索词为“膝骨关节炎,关节炎评估系统,六自由度步态分析”,通过纳入与排除标准,最终选择65篇文献进行归纳总结。结果与结论:①六自由度步态分析提高了评估膝骨关节炎严重程度的准确性,依据该方法制定的治疗方案显著改善了患者的预后;②基于目前的研究发现,在临床实践中应规范六自由度步态分析与传统评估方法的结合,以便客观准确地评估膝骨关节炎,从而更好地选择治疗方案及评估个体化治疗策略的长期有效性。 展开更多
关键词 膝骨关节炎 评估系统 六自由度步态分析 传统评估方法 个体化治疗
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新闻自由还是出版自由,这是个问题——兼论Freedom of the Press的翻译问题 被引量:2
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作者 郜书锴 《大理学院学报(综合版)》 CAS 2007年第1期41-43,共3页
在新闻学上,Freedom of the press是个非常重要的术语,其基本内涵是新闻自由,然而对它的翻译却存在很大的差异。原因主要有二,一是Freedom of the press的内涵随媒介形态的变化而变化,二是Press本身具有多重的词义。本文从社会变迁和语... 在新闻学上,Freedom of the press是个非常重要的术语,其基本内涵是新闻自由,然而对它的翻译却存在很大的差异。原因主要有二,一是Freedom of the press的内涵随媒介形态的变化而变化,二是Press本身具有多重的词义。本文从社会变迁和语言学角度进行分析,认为把Freedom of the press译为新闻自由是适宜的。 展开更多
关键词 新闻自由/出版自由 媒介形态 社会变迁 大众传媒
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Paradoxes in Isabel Archer's View of Freedom in The Portrait of a Lady
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作者 李良彦 《海外英语》 2011年第8X期304-305,共2页
In The Portrait of a Lady, Isabel Archer values her liberty higher than a sense of security that might be guaranteed by possessing great fortune. But there are some paradoxes in Isabel Archer's view of freedom, wh... In The Portrait of a Lady, Isabel Archer values her liberty higher than a sense of security that might be guaranteed by possessing great fortune. But there are some paradoxes in Isabel Archer's view of freedom, which have caused her failure in the fulfillment of her view of freedom. 展开更多
关键词 PARADOXES VIEW freedom QUEST FEAR
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The Core Value of American Culture——Freedom
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作者 刘翚 《海外英语》 2012年第19期181-183,共3页
Any understanding of America must come to terms with its central value and ideal.Freedom is such an influential val ue as well as one of the core values of American culture.It remains the sole basis for American socie... Any understanding of America must come to terms with its central value and ideal.Freedom is such an influential val ue as well as one of the core values of American culture.It remains the sole basis for American society as we know.Without free dom the great nation of America would never have been founded.This paper tries to explore freedom as a value and its manifesta tion in USA from four aspects:politics,religion,speech and academics. 展开更多
关键词 CORE VALUE freedom AMERICAN CULTURE
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The Predetermined Failure of Murphy's Quest for Freedom in Closed Systems--Narritivity Temporality in Murphy
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作者 杨静 《海外英语》 2018年第6期179-181,共3页
This essay aims at an analysis of Murphy's failure of his quest for freedom from the aspect of narrative temporality whichwill focus on order, duration and frequency. From the perspective of temporal order, the es... This essay aims at an analysis of Murphy's failure of his quest for freedom from the aspect of narrative temporality whichwill focus on order, duration and frequency. From the perspective of temporal order, the essay will endeavor to probe into the pro-lepsis in the novel to analyse predetermined narrative and its function. Considering with temporal duration, this essay will penetratethe deceleration of narrative—scene and pause in Murphy to explore its thematic meaning. To investigate the temporal frequency,iterative narrative within text will be exemplified to discuss closed systems in the novel. Based on the analysis of the narrativity tem-porality in Murphy, the essay will focuses on that how its narrative strategy well embodies its theme—the predetermined failure ofMurphy's quest for freedom in closed systems. 展开更多
关键词 narrative temporality closed system predetermined freedom
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解读单元考点,牵手高频考题——Unit 14 Freedom fighters(英文)
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作者 李也白 《中学生英语(高中版)》 2008年第8期16-17,共2页
1. Often blacks were not allowed intohotels, schools or libraries at all. (Page 28)【考点】allow的用法【归纳】allow 意为"允许, 准许"。用法有:allow sth. doing sth.allow sb. to do sth.allow sb. sth.allow for +... 1. Often blacks were not allowed intohotels, schools or libraries at all. (Page 28)【考点】allow的用法【归纳】allow 意为"允许, 准许"。用法有:allow sth. doing sth.allow sb. to do sth.allow sb. sth.allow for +n. (考虑, 顾及) / doing / obj.+ 展开更多
关键词 Unit 14 freedom fighters
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Experimental Study on Interaction Between Degrees of Freedom in a Wave Buoy 被引量:6
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作者 HUANG Shuting SHI Hongda +6 位作者 CAO Feifei TAN Junzhe CHENG Haixun LI Demin LIU Shangze GONG Haoxiang TAO Ji 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第6期1256-1264,共9页
Increasing degrees of freedom(DOFs)is a useful way to raise the power capture efficiency of oscillating wave energy converters.Thus,this study proposes a buoy with three DOFs,which are surge,heave,and pitch.The hydrod... Increasing degrees of freedom(DOFs)is a useful way to raise the power capture efficiency of oscillating wave energy converters.Thus,this study proposes a buoy with three DOFs,which are surge,heave,and pitch.The hydrodynamic performance and power capture efficiency of the buoy is physically modeled.Amplitudes of unidirectional and coupled motions are compared to analyze the interaction effect between freedoms under conditions with and without power take-off damping.The capture width ratio and corresponding growth rates are also calculated.Results show that the buoy makes a periodic sinusoidal(or approximate)movement in every DOF.Coupling effect can cause an increase in the amplitude in one DOF and a decrease in the amplitudes of the others.This phenomenon shows that the kinematic energy of the buoy redistributes to all DOFs compared with the unidirectional conditions.Adding DOFs can improve the power absorption of the buoy in most cases,but the number of DOFs is not the more the better. 展开更多
关键词 WAVE energy OSCILLATING BUOY multiple DEGREES of freedom
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Modified Two-Degrees-of-Freedom Internal Model Control for Non-Square Systems with Multiple Time Delays 被引量:25
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作者 Jian-Chang Liu Nan Chen Xia Yu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第2期122-128,共7页
A modified two-degrees-of-freedom( M-TDOF) internal model control( IMC) method is proposed for non-square systems with multiple time delays and right-half-plane( RHP) zeros. In this method,pseudo-inverse is introduced... A modified two-degrees-of-freedom( M-TDOF) internal model control( IMC) method is proposed for non-square systems with multiple time delays and right-half-plane( RHP) zeros. In this method,pseudo-inverse is introduced to design the internal model controller,and a desired closed-loop transfer function is designed to eliminate the unrealizable factors of the derived controller. In addition,set-point tracking and load-disturbance rejection of each process are separately controlled by two controllers. The simulation results show that in addition to high decoupling performance and robustness,the proposed control method also effectively improves loaddisturbance rejection and simultaneously optimizes the input tracking performance and disturbance rejection performance by selecting the parameters of controllers. Furthermore,the higher tolerance of model mismatch is achieved in this paper. 展开更多
关键词 non-square system two degrees of freedom internal model control
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System Identification Modeling of Ship Manoeuvring Motion in 4 Degrees of Freedom Based on Support Vector Machines 被引量:7
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作者 王雪刚 邹早建 +1 位作者 余龙 蔡韡 《China Ocean Engineering》 SCIE EI CSCD 2015年第4期519-534,共16页
Based on support vector machines, three modeling methods, i.e., white-box modeling, grey-box modeling and black-box modeling of ship manoeuvring motion in 4 degrees of freedom are investigated. With the whole-ship mat... Based on support vector machines, three modeling methods, i.e., white-box modeling, grey-box modeling and black-box modeling of ship manoeuvring motion in 4 degrees of freedom are investigated. With the whole-ship mathematical model for ship manoeuvring motion, in which the hydrodynamic coefficients are obtained from roll planar motion mechanism test, some zigzag tests and turning circle manoeuvres are simulated. In the white-box modeling and grey-box modeling, the training data taken every 5 s from the simulated 20°/20° zigzag test are used, while in the black-box modeling, the training data taken every 5 s from the simulated 15°/15°, 20°/20° zigzag tests and 15°, 25° turning manoeuvres are used; and the trained support vector machines are used to predict the whole 20°/20° zigzag test. Comparisons between the simulated and predicted 20°/20° zigzag tests show good predictive ability of the proposed methods. Besides, all mathematical models obtained by the proposed modeling methods are used to predict the 10°/10° zigzag test and 35° turning circle manoeuvre, and the predicted results are compared with those of simulation tests to demonstrate the good generalization performance of the mathematical models. Finally, the proposed modeling methods are analyzed and compared with each other in aspects of application conditions, prediction accuracy and computation speed. The appropriate modeling method can be chosen according to the intended use of the mathematical models and the available data needed for system identification. 展开更多
关键词 ship manoeuvring 4 degrees of freedom system identification support vector machines
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Bionic Quadruped Robot Dynamic Gait Control Strategy Based on Twenty Degrees of Freedom 被引量:4
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作者 Dawei Gong Peng Wang +2 位作者 Shuangyu Zhao Li Du Yu Duan 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第1期382-388,共7页
Quadruped robot dynamic gaits have much more advantages than static gaits on speed and efficiency, however high speed and efficiency calls for more complex mechanical structure and complicated control algorithm. It be... Quadruped robot dynamic gaits have much more advantages than static gaits on speed and efficiency, however high speed and efficiency calls for more complex mechanical structure and complicated control algorithm. It becomes even more challenging when the robot has more degrees of freedom.As a result, most of the present researches focused on simple robot, while the researches on dynamic gaits for complex robot with more degrees of freedom are relatively limited. The paper is focusing on the dynamic gaits control for complex robot with twenty degrees of freedom for the first time. Firstly, we build a relatively complete 3 D model for quadruped robot based on spring loaded inverted pendulum(SLIP) model, analyze the inverse kinematics of the model, plan the trajectory of the swing foot and analyze the hydraulic drive. Secondly, we promote the control algorithm of one-legged to the quadruped robot based on the virtual leg and plan the state variables of pace gait and bound gait. Lastly, we realize the above two kinds of dynamic gaits in ADAMS-MATLAB joint simulation platform which testify the validity of above method. 展开更多
关键词 Degree of freedom dynamic gait foot trajectory quadruped robot spring loaded inverted pendulum(SLIP)
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The number of least degrees of freedom required for a polarization controller to transform any state of polarization to any other output covering the entire Poincar sphere 被引量:2
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作者 张晓光 郑远 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第7期2509-2513,共5页
Using two typical types of polarization controller, this paper analyses theoretically and experimentally the fact that it is necessary to adjust at least three instead of two waveplates in order to transform any state... Using two typical types of polarization controller, this paper analyses theoretically and experimentally the fact that it is necessary to adjust at least three instead of two waveplates in order to transform any state of polarization to any other output covering the entire Poincar6 sphere. The experimental results are exactly in accordance with the theory discussed in this paper. It has corrected the conventional and inaccurate point of view that two waveplates of a polarization controller are adequate to complete the transformation of state of polarization. 展开更多
关键词 polarization controller degree of freedom state of polarization
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Physical Modeling and Parametric Study on Two-Degree-of-Freedom VIV of A Cylinder near Rigid Wall 被引量:3
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作者 杨兵 高福平 +1 位作者 李东晖 吴应湘 《China Ocean Engineering》 SCIE EI 2009年第1期119-132,共14页
Unlike most previous studies on the transverse vortex-induced vibration(VlV) of a cylinder mainly under the wallfree condition (Williamson & Govardhan, 2004), this paper experimentally investigates the vortex-ind... Unlike most previous studies on the transverse vortex-induced vibration(VlV) of a cylinder mainly under the wallfree condition (Williamson & Govardhan, 2004), this paper experimentally investigates the vortex-induced vibration of a cylinder with two degrees of freedom near a rigid wall exposed to steady flow. The amplitude and frequency responses of the cylinder are discussed. The lee wake flow patterns of the cylinder undergoin^g VIV were visualized by employing the hydrogen bubble technique. The effects of the gap-to-diameter ratio (eo/D) and the mass ratio on the vibration amplitude and frequency are analyzed. Comparisons of VIV response of the cylinder are made between one degree (only transverse) and two degrees of freedom (streamwise and transverse) and those between the present study and previous ones. The experimental observation indicates that there are two types of streamwise vibration, i.e. the first streamwise vibration (FSV) with small amplitude and the second streamwise vibration (SSV) which coexists with transverse vibration. The vortex shedding pattern for the FSV is approximately syrmnetric and that for the SSV is ahernate. The first streamwise vibration tends to disappear with the decrease of eo/D. For the case of large gap-to-dianeter ratios ( e.g. eo/D = 0. 54 ~ 1.58), the maximum amplitudes of the second streamwise vibration and transverse one increase with the increasing gap- to-diameter ratio. But for the case of small gap-to-diameter ratios (e. g. eo/D= 0. 16, 0.23), the vibration amplitude of the cylinder increases slowly at the initial stage (i.e. at small reduced velocity Vr), and across the maximum amplitude it decreases quickly at the last stage (i.e. at large Vr). Within the range of the examined small mass ratio (m 〈 4), both streamwise and transverse vibration amplitude of the cylinder decrease with the increase of mass ratio for the fixed value of Vr- The vibration range ( in terms of Vr) tends to widen with the decrease of the mass ratio. In the second streamwise vibration region, the vibration frequency of the cylinder with a small mass ratio ( e.g. mx = 1.44) undergoes a jump at a certain Vr+ The maximum amplitudes of the transverse vibration for two-degree-of-freedom case is larger than that for one-degree-of-freedom case, but the transverse vibration frequency of the cylinder with two degrees of freedom is lower than that with one degree of freedom(transverse). 展开更多
关键词 vortex-induced vibration cylinder near a wall two degrees of freedom steady flow gap-to-diameter ratio mass ratio
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