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基于比赛需求的足球技术能力测试方法创新设计与实证检验

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中国体育科技 2024年第3期60卷 3-13页

作者：王法鹏李春满高胜杰李翔张先达北京体育大学北京100084

目的:以现行足球技术能力测试存在的问题为依据,从比赛需求角度出发,依据体育测量与评价设计原则和程序,设计一种综合足球技术能力测试(comprehensive football skill test,CFST),验证其信度和效度,并初步制定评分标准。方法:采用文献... 详细信息

目的:以现行足球技术能力测试存在的问题为依据,从比赛需求角度出发,依据体育测量与评价设计原则和程序,设计一种综合足球技术能力测试(comprehensive football skill test,CFST),验证其信度和效度,并初步制定评分标准。方法:采用文献资料调研法构建设计依据;采用测试法对U17和U20共155名男子非守门员球员进行测试,并结合问卷调查法和数理统计法验证测试方法的信度和效度。结果:CFST前两次测试间存在一定程度学习效应,之后几次测试间不再存在学习效应;4次测试之间的重测相关性(r=0.50~0.84,ICC=0.43~0.82)和重测一致性(SEM%=1.69~9.40,RLOA=0.91~1.02×/÷1.05~1.27)良好;CFST涵盖比赛常用足球技术,各测试子项目相互独立。一级球员整体表现显著优于二级和无等级球员(P0.05)。结论:CFST具有中到强相关的重测相关性和良好的重测一致性,能较准确反映受试者的技术能力水平;CFST具有良好的内容效度和结构效度,测试内容全面,符合比赛需求,能够有效区分不同水平球员。

关键词：足球技术测试信度效度

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Blind source separation with unknown and dynamically changing number of source signals

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Science in China(Series F) 2006年第5期49卷 627-638页

作者： YE Jimin zhang xianda ZHU Xiaolong Key Laboratory for Radar Signal Processing Xidian University Xi'an 710071 China Department of Automation State Key Laboratory of Intelligent Technology and Systems Tsinghua University Beijing 100084 China

The contrast function remains to be an open problem in blind source separation （BSS） when the number of source signals is unknown and/or dynamically changed. The paper studies this problem and proves that the mutual information is still the contrast function for BSS if the mixing matrix is of full column rank. The mutual information reaches its minimum at the separation points, where the random outputs of the BSS system are the scaled and permuted source signals, while the others are zero outputs. Using the property that the transpose of the mixing matrix and a matrix composed by m observed signals have the indentical null space with probability one, a practical method, which can detect the unknown number of source signals n, ulteriorly traces the dynamical change of the sources number with a few of data, is proposed. The effectiveness of the proposed theorey and the developed novel algorithm is verified by adaptive BSS simulations with unknown and dynamically changing number of source signals.

关键词： blind source separation independent component analysis natural gradient mutual information contrast function neural networks.

Wireless multicarrier digital transmission via frames： Capacity analysis and optimization design

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Frontiers of Electrical and Electronic Engineering in China 2012年第2期7卷 261-269页

作者： Fangming HAN xianda zhang Department of Automation Tsinghua UniversityBeijing 100084China Tsinghua National Laboratory for Information Science and Technology Tsinghua UniversityBeijing 100084China

By treating information transmission as tiling over the time-frequency plane, we propose a digital signal transmission scheme employing overcomplete frames as modulation pulses. The new scheme can achieve a signaling rate larger than the Nyquist rate. We first analyze the capacity performance of the frame transmission scheme over additive white Gaussian noise （AWGN） channels, k proves that the proposed scheme can achieve the Shannon capacity asymptotically. Next, we design the Gabor frame system parameters in time-frequency dispersive channels. It is shown that the pulses shape and the time-frequency separation should be matched to the channel dispersion parameters to achieve the minimum energy perturbation. Numerical results are presented to verify the theoretical findings.

关键词： overcomplete frame Nyquist rate signalingefficiency capacity

FEATURE EXTRACTION AND RECOGNITION FOR ECHOES OF HRR RADAR

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Journal of Electronics(China) 2009年第6期26卷 788-793页

作者： Xie Deguang zhang xianda Department of Automation Tsinghua University Beijing 100084 China

This paper describes a novel target recognition scheme using High Range Resolution (HRR) radar signatures. AutoRegressive (AR) method is used to extract features from HRR radar echoes based on scattering center model of target. The optimal linear transformation based on Euclidian distribution distance criterion is performed on AR model parameter vectors to reduce dimension of feature vectors further and improve the class discrimination capability of feature vectors. The optimization algorithm is designed utilizing the quadratic property of criterion function and Gaussian kernel based Parzen window density function estimator. The concept of Stochastic Information Gradient (SIG) is incorporated into the gradient of cost function to decrease the computational complexity of the algorithm. Simulation results using three real airplanes,data show the effectiveness of the proposed method.

关键词： Radar target recognition Feature extraction AutoregRessive (AR) model Densityfunction estimation Stochastic Information Gradient (SIG)

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吴门医派手法治疗胸腰椎压缩性骨折临床研究

中医药临床杂志 2024年第1期36卷 172-177页

作者：李稳超李红卫张先达李宇卫安徽中医药大学研究生院安徽合肥230000 江苏省苏州市中医医院江苏苏州215000

目的:通过观察吴门医派手法保守治疗胸腰椎骨折的临床疗效以及影像学指标,探索吴门医派手法治疗胸腰椎骨折临床的疗效。方法:选择胸腰椎压缩骨折患者80例,采用随机数字表法分为治疗组与对照组,每组40例,对照组患者行常规保守治疗,治疗... 详细信息

目的:通过观察吴门医派手法保守治疗胸腰椎骨折的临床疗效以及影像学指标,探索吴门医派手法治疗胸腰椎骨折临床的疗效。方法:选择胸腰椎压缩骨折患者80例,采用随机数字表法分为治疗组与对照组,每组40例,对照组患者行常规保守治疗,治疗组在常规保守治疗的基础上采用吴门医派手法治疗,比较2组患者治疗前、治疗后3d、治疗后3月、末次回访的VAS评分、Oswestry功能障碍指数、伤椎局部后凸角、椎体楔角和椎体前缘高度比以及末次随访时影像学指标变化以及中医症候评分。结果:治疗组有效率为95%,对照组为80%,差异具备统计学意义;2组患者术前VAS腰痛评分、ODI指数比较,差异不具备统计学意义;2组患者治疗后3d、治疗后3月、末次回访VAS腰痛评分、ODI指数比较,治疗组VAS腰痛评分、ODI指数明显低于对照组,差异有统计学意义;治疗前治疗组患者以及对照组患者的局部后凸角、椎体楔形角、椎体前缘高度比较,差异不具备统计学意义;治疗后治疗组患者以及对照组患者的局部后凸角、椎体楔形角、椎体前缘高度比较,治疗组影像学指标优于对照组,差异具备统计学意义;治疗前、后治疗组患者与对照组患者的局部后凸角丢失度、椎体楔形角丢失度、椎体前缘高度丢失值比较,治疗组明显低于对照组,差异有统计学意义。结论:吴门医派手法在治疗胸腰椎压缩性骨折能够有效缓解患者疼痛,可恢复一定的椎体高度,具有操作简单、并发症少、安全性高等优点。

关键词：胸腰椎压缩性骨折吴门医派手法保守治疗

阿胶益寿口服液指纹图谱及4种成分的含量测定

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湖北理工学院学报 2024年第2期40卷 56-60,65页

作者：肖安菊李董谭洁程文春张贤达湖北理工学院医学院湖北黄石435003 远大医药黄石飞云制药有限公司湖北黄石435100 黄石市食品药品检验检测技术中心湖北黄石435000

为了建立阿胶益寿口服液的高效液相色谱指纹图谱,同时测定制剂水解产生的L-羟脯氨酸、甘氨酸、丙氨酸、L-脯氨酸的含量,采用异硫氰酸苯酯衍生化、高效液相色谱法检测得到10批次阿胶益寿口服液的指纹图谱,并采用中药色谱指纹图谱相似度... 详细信息

为了建立阿胶益寿口服液的高效液相色谱指纹图谱,同时测定制剂水解产生的L-羟脯氨酸、甘氨酸、丙氨酸、L-脯氨酸的含量,采用异硫氰酸苯酯衍生化、高效液相色谱法检测得到10批次阿胶益寿口服液的指纹图谱,并采用中药色谱指纹图谱相似度评价系统(2004A)进行相似度评价,确定共同拥有峰;同法测定制剂中4种氨基酸的含量。研究发现,10批次制剂中共有8个共有峰,相似度≥0.9;指认了L-羟脯氨酸(1号峰)、甘氨酸(3号峰)、丙氨酸(4号峰)、L-脯氨酸(5号峰),4种成分的线性关系良好(r≥0.9997),加样回收率平均值分别为104.39%、105.37%、102.89%、105.19%,RSD分别为3.47%、3.50%、3.68%、2.42%。该研究建立的阿胶益寿口服液指纹图谱特征性强,4种氨基酸的含量测定方法简单、准确易行,可为阿胶益寿口服液的质量评价提供参考。

关键词：阿胶益寿口服液指纹图谱氨基酸高效液相色谱法含量测定

COMPUTER SIMULATION OF RAYLEIGH FADING CHANNELS IN MC-CDMA SYSTEMS

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Journal of Electronics(China) 2007年第5期24卷 577-582页

作者： Han Fangming zhang xianda National Laboratory of Radar Signal Processing Xidian University Xi＇an 710071 China National Laboratory of Tsinghua Information Science and Technology Department of AutomationTsinghua University Beijing 100084 China

For Multi-Carrier-Code Division Multiple Access （MC-CDMA） systems, it is usually assumed that the fading of the subcarriers is frequency non-selective and independent of each other. This paper shows that the two assumptions are incompatible. In fact, the MC-CDMA signals at each subcarrier undergo fading that are highly correlated. Based on this observation, this paper develops a simulation algorithm for Rayleigh fading channels via frequency-domain correlation functionl which incorporates the Doppler effect simultaneously. Numerical examples are presented to demonstrate the effectiveness of the new algorithm, with the conclusion that the independence assumption of subcarrier fading overrates the system performance.

关键词： Multi-Carrier-Code Division Multiple Access (MC-CDMA) Rayleigh fading Channelsimulation Frequency-domain correlation

Blind　Equalization　Based　on　Evolution　Strategies

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通信学报 1997年第3期18卷 60-64页

作者： Song Yu zhang xianda Li Yanda (Dept Automation,Tsinghua University, Beijing 100084)

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关键词：盲道均衡数字通信码间干扰

A SIGNAL-ADAPTIVE ALGORITHM FOR BLIND SEPARATION OF SOURCES WITH MIXED KURTOSIS SIGNS

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Journal of Electronics(China) 2006年第3期23卷 399-403页

作者： Zhu Xiaolong zhang xianda Department of Automation Tsinghua University Beijing 100084 China

This paper addresses the problem of Blind Source Separation (BSS) and presents a new BSS algorithm with a Signal-Adaptive Activation (SAA) function (SAA-BSS). By taking the sum of absolute values of the normalized kurtoses as a contrast function, the obtained signal-adaptive activation function automatically satisfies the local stability and robustness conditions. The SAA-BSS exploits the natural gradient learning on the Stiefel manifold, and it is an equivariant algorithm with a moderate computational load. Computer simulations show that the SAA-BSS can perform blind separation of mixed sub-Gaussian and super-Gaussian signals and it works more efficiently than the existing algorithms in convergence speed and robustness against outliers.

关键词： Blind Source Separation (BSS) Independent Component Analysis (ICA) Natural gradient Kurtosis Robustness