提出了一种基于DSP的时间计权声级的计算模型,并对计权系数的修正方法进行了深入研究。给出了计算模型的一种基于DSP的算法,并对模型计算结果进行了误差分析。对应用该算法进行典型信号处理的过程进行了仿真研究,结果表明,此方法对于计...提出了一种基于DSP的时间计权声级的计算模型,并对计权系数的修正方法进行了深入研究。给出了计算模型的一种基于DSP的算法,并对模型计算结果进行了误差分析。对应用该算法进行典型信号处理的过程进行了仿真研究,结果表明,此方法对于计算声音信号的时间计权声级有很高的精度,误差不超过0.001 d B,对声学及相关工程领域的时间计权量的实时计算有指导意义。展开更多
Crowd density is an important factor of crowd stability.Previous crowd density estimation methods are highly dependent on the specific video scene.This paper presented a video scene invariant crowd density estimation ...Crowd density is an important factor of crowd stability.Previous crowd density estimation methods are highly dependent on the specific video scene.This paper presented a video scene invariant crowd density estimation method using Geographic Information Systems(GIS) to monitor crowd size for large areas.The proposed method mapped crowd images to GIS.Then we can estimate crowd density for each camera in GIS using an estimation model obtained by one camera.Test results show that one model obtained by one camera in GIS can be adaptively applied to other cameras in outdoor video scenes.A real-time monitoring system for crowd size in large areas based on scene invariant model has been successfully used in 'Jiangsu Qinhuai Lantern Festival,2012'.It can provide early warning information and scientific basis for safety and security decision making.展开更多
文摘提出了一种基于DSP的时间计权声级的计算模型,并对计权系数的修正方法进行了深入研究。给出了计算模型的一种基于DSP的算法,并对模型计算结果进行了误差分析。对应用该算法进行典型信号处理的过程进行了仿真研究,结果表明,此方法对于计算声音信号的时间计权声级有很高的精度,误差不超过0.001 d B,对声学及相关工程领域的时间计权量的实时计算有指导意义。
基金The authors would like to thank the reviewers for their detailed reviews and constructive comments. We are also grateful for Sophie Song＇s help on the improving English. This work was supported in part by the ‘Fivetwelfh＇ National Science and Technology Support Program of the Ministry of Science and Technology of China （No. 2012BAH35B02）, the National Natural Science Foundation of China （NSFC） （No. 41401107, No. 41201402, and No. 41201417）.
文摘Crowd density is an important factor of crowd stability.Previous crowd density estimation methods are highly dependent on the specific video scene.This paper presented a video scene invariant crowd density estimation method using Geographic Information Systems(GIS) to monitor crowd size for large areas.The proposed method mapped crowd images to GIS.Then we can estimate crowd density for each camera in GIS using an estimation model obtained by one camera.Test results show that one model obtained by one camera in GIS can be adaptively applied to other cameras in outdoor video scenes.A real-time monitoring system for crowd size in large areas based on scene invariant model has been successfully used in 'Jiangsu Qinhuai Lantern Festival,2012'.It can provide early warning information and scientific basis for safety and security decision making.
