In order to enhance the authenticity and accuracy of passenger evacuation simulation in ships, a new multi-grid model was proposed on the basis of a traditional cellular automata model. In the new model finer lattices...In order to enhance the authenticity and accuracy of passenger evacuation simulation in ships, a new multi-grid model was proposed on the basis of a traditional cellular automata model. In the new model finer lattices were used, interaction of force among pedestrians or between pedestrians and constructions was considered, and static floor fields in a multi-level exit environment were simplified into cabin and exit static floor fields. Compared with the traditional cellular automata model, the multi-grid model enhanced the continuity of the passengers'track and the precision of the boundary qualifications. The functions of the dislocation distribution of passengers as well as partial overlap of tracks due to congestion were realized. Furthermore, taking the typical cabin environment as an example, the two models were used to analyze passenger evacuation under the same conditions. It was found that the laws of passenger evacuation simulated by the two models are similar, while the simulation's authenticity and accuracy are enhanced by the multi-grid model.展开更多
针对舰船目标非网格多散射点的距离副瓣高、难以有效抑制的问题,采用改进空间谱估计算法——Multiple Signal Classification(MUSIC)对目标多散射点网格偏移量进行解相干和超分辨估计,在此基础上构建目标非网格多散射点模型,提出一种基...针对舰船目标非网格多散射点的距离副瓣高、难以有效抑制的问题,采用改进空间谱估计算法——Multiple Signal Classification(MUSIC)对目标多散射点网格偏移量进行解相干和超分辨估计,在此基础上构建目标非网格多散射点模型,提出一种基于最小均方误差(Minimum Mean Squared Error, MMSE)准则的非网格强散射点距离副瓣抑制算法。仿真和实测数据结果表明,该算法在准确估计非网格偏移量的基础上,能够有效抑制距离非网格多散射点目标的副瓣。展开更多
船用直流电网的主谐波频率高达数千赫兹,并且谐波成分在几千至十几千赫兹均有分布。传统的有源电力滤波器(Active Power Filter,APF)基于时域信号对谐波进行跟踪抑制,受制于运算时硬件造成的固有延时,无法准确跟踪高频率的谐波。鉴于此...船用直流电网的主谐波频率高达数千赫兹,并且谐波成分在几千至十几千赫兹均有分布。传统的有源电力滤波器(Active Power Filter,APF)基于时域信号对谐波进行跟踪抑制,受制于运算时硬件造成的固有延时,无法准确跟踪高频率的谐波。鉴于此,论文分析并设计了基于时延陷波滤波x-最小均方(filter-x Least Mean Square,FXLMS)算法的自适应APF。所设计的APF能抑制20kHz以内的若干个任意频点的谐波。搭建了基于现场可编辑逻辑门阵列(Field Programmable Gate Array,FPGA)的APF试验平台进行试验验证。试验以5kHz、10kHz、15kHz的复合频率谐波为例,APF装置对预设谐波频点抑制效果均达到24dB以上,实现了对高频谐波抑制。展开更多
为了提高大型船舶轨迹的停留检测效率,提出一种基于网格的停留轨迹检测方法,通过对矢量轨迹进行网格化提高运算效率,以轨迹点总停留时间作为网格密度解决轨迹点采样时间不均的问题。为了验证方法的实用性,采用真实样例轨迹数据进行检测...为了提高大型船舶轨迹的停留检测效率,提出一种基于网格的停留轨迹检测方法,通过对矢量轨迹进行网格化提高运算效率,以轨迹点总停留时间作为网格密度解决轨迹点采样时间不均的问题。为了验证方法的实用性,采用真实样例轨迹数据进行检测和分类实验。实验结果表明:在检测效果方面,该方法检测正确率均高于88%且召回率均高于80%,能够满足停留检测的需求;在分类效果方面,其整体分类结果较为准确,能够有效区分锚泊和靠泊两种情况;在检测效率方面,该算法优于基于密度的噪声应用空间聚类(Density-Based Spatial Clustering of Applications with Noise, DBSCAN)检测方法和基于空间关系的检测方法,且更适用于大数据量的处理。展开更多
基金Supported by the Ph.D Programs Foundation of Ministryof Education of China under Grant No.201023041108the Fundamental Research Funds for the Central Universities under Grant No.61004008
文摘In order to enhance the authenticity and accuracy of passenger evacuation simulation in ships, a new multi-grid model was proposed on the basis of a traditional cellular automata model. In the new model finer lattices were used, interaction of force among pedestrians or between pedestrians and constructions was considered, and static floor fields in a multi-level exit environment were simplified into cabin and exit static floor fields. Compared with the traditional cellular automata model, the multi-grid model enhanced the continuity of the passengers'track and the precision of the boundary qualifications. The functions of the dislocation distribution of passengers as well as partial overlap of tracks due to congestion were realized. Furthermore, taking the typical cabin environment as an example, the two models were used to analyze passenger evacuation under the same conditions. It was found that the laws of passenger evacuation simulated by the two models are similar, while the simulation's authenticity and accuracy are enhanced by the multi-grid model.
文摘针对舰船目标非网格多散射点的距离副瓣高、难以有效抑制的问题,采用改进空间谱估计算法——Multiple Signal Classification(MUSIC)对目标多散射点网格偏移量进行解相干和超分辨估计,在此基础上构建目标非网格多散射点模型,提出一种基于最小均方误差(Minimum Mean Squared Error, MMSE)准则的非网格强散射点距离副瓣抑制算法。仿真和实测数据结果表明,该算法在准确估计非网格偏移量的基础上,能够有效抑制距离非网格多散射点目标的副瓣。
文摘船用直流电网的主谐波频率高达数千赫兹,并且谐波成分在几千至十几千赫兹均有分布。传统的有源电力滤波器(Active Power Filter,APF)基于时域信号对谐波进行跟踪抑制,受制于运算时硬件造成的固有延时,无法准确跟踪高频率的谐波。鉴于此,论文分析并设计了基于时延陷波滤波x-最小均方(filter-x Least Mean Square,FXLMS)算法的自适应APF。所设计的APF能抑制20kHz以内的若干个任意频点的谐波。搭建了基于现场可编辑逻辑门阵列(Field Programmable Gate Array,FPGA)的APF试验平台进行试验验证。试验以5kHz、10kHz、15kHz的复合频率谐波为例,APF装置对预设谐波频点抑制效果均达到24dB以上,实现了对高频谐波抑制。
文摘为了提高大型船舶轨迹的停留检测效率,提出一种基于网格的停留轨迹检测方法,通过对矢量轨迹进行网格化提高运算效率,以轨迹点总停留时间作为网格密度解决轨迹点采样时间不均的问题。为了验证方法的实用性,采用真实样例轨迹数据进行检测和分类实验。实验结果表明:在检测效果方面,该方法检测正确率均高于88%且召回率均高于80%,能够满足停留检测的需求;在分类效果方面,其整体分类结果较为准确,能够有效区分锚泊和靠泊两种情况;在检测效率方面,该算法优于基于密度的噪声应用空间聚类(Density-Based Spatial Clustering of Applications with Noise, DBSCAN)检测方法和基于空间关系的检测方法,且更适用于大数据量的处理。
