维多利亚电子文件战略(Victorian Electronic Records Strategy,VERS)由澳大利亚维多利亚州公共记录办公室(PROV)负责推动与发布,其核心目标是确保维多利亚州公共部门能够创建、获取和保存那些真实、完整和有意义的数字记录。PROV相继于...维多利亚电子文件战略(Victorian Electronic Records Strategy,VERS)由澳大利亚维多利亚州公共记录办公室(PROV)负责推动与发布,其核心目标是确保维多利亚州公共部门能够创建、获取和保存那些真实、完整和有意义的数字记录。PROV相继于1999年、2003年发布了VERS V1标准、VERS V2标准。展开更多
日前,索尼推出了电影摄影机CineAltaB Ver 2.01版本固件升级。新版本包含更多录制模式,其中包括3.8K全画幅裁切模式(最高支持120帧/秒的拍摄帧率)和1.9K模式(最高支持240帧/秒的拍摄帧率)。这些新的录制模式使电影制作人能够根据实际应...日前,索尼推出了电影摄影机CineAltaB Ver 2.01版本固件升级。新版本包含更多录制模式,其中包括3.8K全画幅裁切模式(最高支持120帧/秒的拍摄帧率)和1.9K模式(最高支持240帧/秒的拍摄帧率)。这些新的录制模式使电影制作人能够根据实际应用需求,优先选择更高的传感器性能。同时新增1.8倍画面拉伸还原设置,以及更多高帧率(慢动作和快动作)模式,帧率可达66、72、75、88、90、96和110帧/秒,并将为24.00帧/秒的录制格式添加代理录制功能。展开更多
The present research study assesses the accuracy of two recent freely available ASTER-GDEM ver.2, SRTM ver.4.1 digital elevation models for parts of the lowest area on the earth on the shores of the Dead Sea, the site...The present research study assesses the accuracy of two recent freely available ASTER-GDEM ver.2, SRTM ver.4.1 digital elevation models for parts of the lowest area on the earth on the shores of the Dead Sea, the site located over areas with high variation in topography within the “humratessahan” watershed, where the elevation varies between 700 m above sea level in the north east of the watershed to 210 meter below sea level. The reference elevation data used in this study are topographical points extracted from existing digital vector topographical map published by Royal Jordanian Geographical Center (RJGC). However, the contour lines do not cover the whole area especially in the flat areas where elevation is less than the contour line interval. Therefore, the second reference data created with photogrammetric techniques from stereoscopic pairs of aerial photos had been used for the surface to surface comparison and elevation profiles assessment purpose. It is demonstrated that the vertical accuracy of ASTER-GDEM ver.2 is 22.223 m (Root Mean Square Error (RMSE)) against reference elevation data, while the SRTM ver.4.1 has an RMSE of 15.858 m;the statistics results indicate that the theoretical accuracy is achievable and meets the expected accuracy specification. Furthermore, as for its unprecedented detail, it is believed that the photogrammetric derived DEM offers an alternative in accessibility to high-quality elevation data with vertical accuracy of 0.78 m (Root Mean Square Error (RMSE)).展开更多
对DVB Over IP应用来说,如何传送用可变比特率(VBR)压缩的MPEG-2传输流格式的视频是一个重要的问题。其中以传统的恒定速率(CBR)方式传送VBR视频时,接收端需要较大的缓存和开始延时时间;而另一种新的采用PCR协助的恒定速率(PCBR)传送方...对DVB Over IP应用来说,如何传送用可变比特率(VBR)压缩的MPEG-2传输流格式的视频是一个重要的问题。其中以传统的恒定速率(CBR)方式传送VBR视频时,接收端需要较大的缓存和开始延时时间;而另一种新的采用PCR协助的恒定速率(PCBR)传送方式,则是以较高的传输速率和以牺牲码率的稳定性来减少缓存需求。为了平衡传输速率和接收端缓存需求,在PCBR基础上,提出了一种称为IPCBR的改进的视频流传送方法。通过实验证明,该新方法与传统的CBR传送方式相比,不仅可降低缓存需求,而且与PCBR方式相比,又具有较高的稳定性和带宽利用率,并克服了PCBR丢包率较高的问题。同时由于该算法特别针对DVB Over IP,具有较强的实用性,且有利于Internet TV业务拓展。展开更多
利用分数导数本构模型模拟系统的阻尼特性,构造了分数阶Ver Del Pol-Duffing系统,探讨了系统的动力特性随特征参数的变化规律。分析发现:该非线性振子具有与经典Ver Del Pol系统相似的自激振动特性,但其非线性强弱受分数导数阶值以及阻...利用分数导数本构模型模拟系统的阻尼特性,构造了分数阶Ver Del Pol-Duffing系统,探讨了系统的动力特性随特征参数的变化规律。分析发现:该非线性振子具有与经典Ver Del Pol系统相似的自激振动特性,但其非线性强弱受分数导数阶值以及阻尼系数和非线性大位移系数的影响;在简谐荷载作用下,随着外荷载幅值的增大或阻尼系数的减小,系统由拟周期振动变为周期三振动最后发展为单周期振动;在地震荷载作用下,分数导数阶值的变化能改变系统的输出能量。展开更多
文摘日前,索尼推出了电影摄影机CineAltaB Ver 2.01版本固件升级。新版本包含更多录制模式,其中包括3.8K全画幅裁切模式(最高支持120帧/秒的拍摄帧率)和1.9K模式(最高支持240帧/秒的拍摄帧率)。这些新的录制模式使电影制作人能够根据实际应用需求,优先选择更高的传感器性能。同时新增1.8倍画面拉伸还原设置,以及更多高帧率(慢动作和快动作)模式,帧率可达66、72、75、88、90、96和110帧/秒,并将为24.00帧/秒的录制格式添加代理录制功能。
文摘The present research study assesses the accuracy of two recent freely available ASTER-GDEM ver.2, SRTM ver.4.1 digital elevation models for parts of the lowest area on the earth on the shores of the Dead Sea, the site located over areas with high variation in topography within the “humratessahan” watershed, where the elevation varies between 700 m above sea level in the north east of the watershed to 210 meter below sea level. The reference elevation data used in this study are topographical points extracted from existing digital vector topographical map published by Royal Jordanian Geographical Center (RJGC). However, the contour lines do not cover the whole area especially in the flat areas where elevation is less than the contour line interval. Therefore, the second reference data created with photogrammetric techniques from stereoscopic pairs of aerial photos had been used for the surface to surface comparison and elevation profiles assessment purpose. It is demonstrated that the vertical accuracy of ASTER-GDEM ver.2 is 22.223 m (Root Mean Square Error (RMSE)) against reference elevation data, while the SRTM ver.4.1 has an RMSE of 15.858 m;the statistics results indicate that the theoretical accuracy is achievable and meets the expected accuracy specification. Furthermore, as for its unprecedented detail, it is believed that the photogrammetric derived DEM offers an alternative in accessibility to high-quality elevation data with vertical accuracy of 0.78 m (Root Mean Square Error (RMSE)).
文摘对DVB Over IP应用来说,如何传送用可变比特率(VBR)压缩的MPEG-2传输流格式的视频是一个重要的问题。其中以传统的恒定速率(CBR)方式传送VBR视频时,接收端需要较大的缓存和开始延时时间;而另一种新的采用PCR协助的恒定速率(PCBR)传送方式,则是以较高的传输速率和以牺牲码率的稳定性来减少缓存需求。为了平衡传输速率和接收端缓存需求,在PCBR基础上,提出了一种称为IPCBR的改进的视频流传送方法。通过实验证明,该新方法与传统的CBR传送方式相比,不仅可降低缓存需求,而且与PCBR方式相比,又具有较高的稳定性和带宽利用率,并克服了PCBR丢包率较高的问题。同时由于该算法特别针对DVB Over IP,具有较强的实用性,且有利于Internet TV业务拓展。
文摘利用分数导数本构模型模拟系统的阻尼特性,构造了分数阶Ver Del Pol-Duffing系统,探讨了系统的动力特性随特征参数的变化规律。分析发现:该非线性振子具有与经典Ver Del Pol系统相似的自激振动特性,但其非线性强弱受分数导数阶值以及阻尼系数和非线性大位移系数的影响;在简谐荷载作用下,随着外荷载幅值的增大或阻尼系数的减小,系统由拟周期振动变为周期三振动最后发展为单周期振动;在地震荷载作用下,分数导数阶值的变化能改变系统的输出能量。
