为了分析压缩感知宽带接收机的性能损失,明确其适用范围,设计了一种基于调制宽带转换器(MWC)结构的压缩感知宽带接收机,并针对该接收机的无杂散动态范围进行仿真分析和实验测量。仿真分析和实测结果表明,字典基之间非正交性将会导致接...为了分析压缩感知宽带接收机的性能损失,明确其适用范围,设计了一种基于调制宽带转换器(MWC)结构的压缩感知宽带接收机,并针对该接收机的无杂散动态范围进行仿真分析和实验测量。仿真分析和实测结果表明,字典基之间非正交性将会导致接收机无杂散动态范围的严重损失,在1/2压缩采样率的条件下,接收机无杂散动态范围仅能达到7 d B左右,这将严重限制压缩感知宽带接收机在高动态范围要求环境下的应用。展开更多
A displacement sensor based on the fiber Fabry-Perot (F-P) cavity was proposed in this paper. Theoretical and experimental analyses were presented. Displacement resolution was demonstrated by spectrum-domain experimen...A displacement sensor based on the fiber Fabry-Perot (F-P) cavity was proposed in this paper. Theoretical and experimental analyses were presented. Displacement resolution was demonstrated by spectrum-domain experiments to obtain the dynamic range of the F-P sensor, and a piezoelectric crystal unit (PZT) was used as the driver. The output signal was modulated by a piezoelectric ceramic ring and demodulated by a phase-locked oscillator. The experimental results show that the displacement resolution of the F-P sensor is less than 5 nm and the dynamic range is more than 100 μm. As acceleration is the second-order differential of displacement, an accelerometer model was proposed using the finite element method (FEM) nd ANSYS software.展开更多
Quantitative analysis is increasingly being used in team sports to better understand performance in these stylized,delineated,complex social systems.Here,the authors provide a first step toward understanding the patte...Quantitative analysis is increasingly being used in team sports to better understand performance in these stylized,delineated,complex social systems.Here,the authors provide a first step toward understanding the pattern-forming dynamics that emerge from collective offensive and defensive behavior in team sports.The authors propose a novel method of analysis that captures how teams occupy sub-areas of the field as the ball changes location.The authors use this method to analyze a game of association football(soccer) based upon a hypothesis that local player numerical dominance is key to defensive stability and offensive opportunity.The authors find that the teams consistently allocated more players than their opponents in sub-areas of play closer to their own goal.This is consistent with a predominantly defensive strategy intended to prevent yielding even a single goal.The authors also find differences between the two teams' strategies:while both adopted the same distribution of defensive,midfield,and attacking players(a 4:3:3 system of play),one team was significantly more effective in maintaining both defensive and offensive numerical dominance for defensive stability and offensive opportunity.That team indeed won the match with an advantage of one goal(2 to 1) but the analysis shows the advantage in play was more pervasive than the single goal victory would indicate.The proposed focus on the local dynamics of team collective behavior is distinct from the traditional focus on individual player capability.It supports a broader view in which specific player abilities contribute within the context of the dynamics of multiplayer team coordination and coaching strategy.By applying this complex system analysis to association football,the authors can understand how players' and teams' strategies result in successful and unsuccessful relationships between teammates and opponents in the area of play.展开更多
文摘为了分析压缩感知宽带接收机的性能损失,明确其适用范围,设计了一种基于调制宽带转换器(MWC)结构的压缩感知宽带接收机,并针对该接收机的无杂散动态范围进行仿真分析和实验测量。仿真分析和实测结果表明,字典基之间非正交性将会导致接收机无杂散动态范围的严重损失,在1/2压缩采样率的条件下,接收机无杂散动态范围仅能达到7 d B左右,这将严重限制压缩感知宽带接收机在高动态范围要求环境下的应用。
基金Project (No. 111303-8112D2) supported by the National DefenseResearch Foundation of Zhejiang University, China
文摘A displacement sensor based on the fiber Fabry-Perot (F-P) cavity was proposed in this paper. Theoretical and experimental analyses were presented. Displacement resolution was demonstrated by spectrum-domain experiments to obtain the dynamic range of the F-P sensor, and a piezoelectric crystal unit (PZT) was used as the driver. The output signal was modulated by a piezoelectric ceramic ring and demodulated by a phase-locked oscillator. The experimental results show that the displacement resolution of the F-P sensor is less than 5 nm and the dynamic range is more than 100 μm. As acceleration is the second-order differential of displacement, an accelerometer model was proposed using the finite element method (FEM) nd ANSYS software.
基金supported by the Portuguese Foundation for Science and Technology(SFRH/BD/43251/2008)
文摘Quantitative analysis is increasingly being used in team sports to better understand performance in these stylized,delineated,complex social systems.Here,the authors provide a first step toward understanding the pattern-forming dynamics that emerge from collective offensive and defensive behavior in team sports.The authors propose a novel method of analysis that captures how teams occupy sub-areas of the field as the ball changes location.The authors use this method to analyze a game of association football(soccer) based upon a hypothesis that local player numerical dominance is key to defensive stability and offensive opportunity.The authors find that the teams consistently allocated more players than their opponents in sub-areas of play closer to their own goal.This is consistent with a predominantly defensive strategy intended to prevent yielding even a single goal.The authors also find differences between the two teams' strategies:while both adopted the same distribution of defensive,midfield,and attacking players(a 4:3:3 system of play),one team was significantly more effective in maintaining both defensive and offensive numerical dominance for defensive stability and offensive opportunity.That team indeed won the match with an advantage of one goal(2 to 1) but the analysis shows the advantage in play was more pervasive than the single goal victory would indicate.The proposed focus on the local dynamics of team collective behavior is distinct from the traditional focus on individual player capability.It supports a broader view in which specific player abilities contribute within the context of the dynamics of multiplayer team coordination and coaching strategy.By applying this complex system analysis to association football,the authors can understand how players' and teams' strategies result in successful and unsuccessful relationships between teammates and opponents in the area of play.
