针对现有内插结构无反馈分布式视频压缩(DVC)在大图像组条件下存在严重解码延时问题,研究了外推结构的无反馈DVC系统。在编码端,提出一种不等保护码率控制算法,该算法在编码端利用快速运动估计外推产生较高质量的边信息估计,根据比特平...针对现有内插结构无反馈分布式视频压缩(DVC)在大图像组条件下存在严重解码延时问题,研究了外推结构的无反馈DVC系统。在编码端,提出一种不等保护码率控制算法,该算法在编码端利用快速运动估计外推产生较高质量的边信息估计,根据比特平面误码率和比特平面重要性,实现比特平面级的码率控制;在解码端提出基于外推内插边信息更新的迭代解码优化,利用更新的边信息对每一分布式帧进行二次解码,在不增加传输码率的条件下进一步提升解码视频质量。实验结果表明,与现有无反馈码率分配算法相比,该算法能够更精确地分配码率,率失真性能提升0.6~1.8 d B,且解码视频图像的主观质量得到明显改善。展开更多
为了解决科考船对科考仪器主机进行远程控制,同时对视频数据进行远程显示的问题,"雪龙2"号科考破冰船进行了有效的探索。船载实验室采用KVM OVER IP(KVM为Keyboard、Video、Mouse的缩写,数字式多计算机切换器,简称IP KVM)和DV...为了解决科考船对科考仪器主机进行远程控制,同时对视频数据进行远程显示的问题,"雪龙2"号科考破冰船进行了有效的探索。船载实验室采用KVM OVER IP(KVM为Keyboard、Video、Mouse的缩写,数字式多计算机切换器,简称IP KVM)和DVCS(Distributed Video Control System,分布式控制系统,简称DVCS)技术,将科考仪器主机和视频显示系统通过网络连接在一起,实现了在科考船其他位置操作科考仪器主机,同时将需要远程显示的视频数据传输到需要的屏幕上。经过在极地现场的实际应用,两套系统操作方便、系统稳定、视频清晰、维护简单,为现场作业的科考队员提供了便利条件,也得到了科考队员的认可。展开更多
The Wyner-Ziv distributed video coding scheme is characterized for its intraframe encoder and interframe decoder which can also approach the efficiency of an interframe encoder-decoder system. In Wyner-Ziv residual co...The Wyner-Ziv distributed video coding scheme is characterized for its intraframe encoder and interframe decoder which can also approach the efficiency of an interframe encoder-decoder system. In Wyner-Ziv residual coding of video, the residual of a frame with respect to a reference frame is Wyner-Ziv encoded, which can reduces the input entropy and leads to a higher coding efficiency than directly encoding the original frame. In this paper, we propose a new approach of residual coding combined with Region Of Interest (ROI) extraction. Experimental results show that, the proposed scheme achieves better rate-distortion performance compared to conventional Wyner-Ziv coding scheme.展开更多
Tin(Sn)holds great promise as an anode material for next-generation lithium(Li)ion batteries but suffers from massive volume change and poor cycling performance.To clarify the dynamic chemical and microstructural evol...Tin(Sn)holds great promise as an anode material for next-generation lithium(Li)ion batteries but suffers from massive volume change and poor cycling performance.To clarify the dynamic chemical and microstructural evolution of Sn anode during lithiation and delithiation,synchrotron X-ray energydispersive diffraction and X-ray tomography are simultaneously employed during Li/Sn cell operation.The intermediate Li-Sn alloy phases during de/lithiation are identified,and their dynamic phase transformation is unraveled which is further correlated with the volume variation of the Sn at particle-and electrode-level.Moreover,we find that the Sn particle expansion/shrinkage induced particle displacement is anisotropic:the displacement perpendicular to the electrode surface(z-axis)is more pronounced compared to the directions(x-and y-axis)along the electrode surface.This anisotropic particle displacement leads to an anisotropic volume variation at the electrode level and eventually generates a net electrode expansion towards the separator after cycling,which could be one of the root causes of mechanical detachment and delamination of electrodes during long-term operation.The unraveled chemical evolution of Li-Sn and deep insights into the microstructural evolution of Sn anode provided here could guide future design and engineering of Sn and other alloy anodes for high energy density Li-and Na-ion batteries.展开更多
文摘针对现有内插结构无反馈分布式视频压缩(DVC)在大图像组条件下存在严重解码延时问题,研究了外推结构的无反馈DVC系统。在编码端,提出一种不等保护码率控制算法,该算法在编码端利用快速运动估计外推产生较高质量的边信息估计,根据比特平面误码率和比特平面重要性,实现比特平面级的码率控制;在解码端提出基于外推内插边信息更新的迭代解码优化,利用更新的边信息对每一分布式帧进行二次解码,在不增加传输码率的条件下进一步提升解码视频质量。实验结果表明,与现有无反馈码率分配算法相比,该算法能够更精确地分配码率,率失真性能提升0.6~1.8 d B,且解码视频图像的主观质量得到明显改善。
文摘为了解决科考船对科考仪器主机进行远程控制,同时对视频数据进行远程显示的问题,"雪龙2"号科考破冰船进行了有效的探索。船载实验室采用KVM OVER IP(KVM为Keyboard、Video、Mouse的缩写,数字式多计算机切换器,简称IP KVM)和DVCS(Distributed Video Control System,分布式控制系统,简称DVCS)技术,将科考仪器主机和视频显示系统通过网络连接在一起,实现了在科考船其他位置操作科考仪器主机,同时将需要远程显示的视频数据传输到需要的屏幕上。经过在极地现场的实际应用,两套系统操作方便、系统稳定、视频清晰、维护简单,为现场作业的科考队员提供了便利条件,也得到了科考队员的认可。
基金Supported by the National Natural Science Foundation of China (No.61003236, 61171053, 61170065)the Doctoral Fund of Ministry of Education of China (No.20113223110002)the Natural Science Major Program for Colleges and Universities in Jiangsu Province(No.11KJA520001)
文摘The Wyner-Ziv distributed video coding scheme is characterized for its intraframe encoder and interframe decoder which can also approach the efficiency of an interframe encoder-decoder system. In Wyner-Ziv residual coding of video, the residual of a frame with respect to a reference frame is Wyner-Ziv encoded, which can reduces the input entropy and leads to a higher coding efficiency than directly encoding the original frame. In this paper, we propose a new approach of residual coding combined with Region Of Interest (ROI) extraction. Experimental results show that, the proposed scheme achieves better rate-distortion performance compared to conventional Wyner-Ziv coding scheme.
基金sponsored by the Helmholtz Association,the China Scholarship Council(CSC)partially funded by the German Research Foundation,DFG(Project No.MA 5039/4-1)。
文摘Tin(Sn)holds great promise as an anode material for next-generation lithium(Li)ion batteries but suffers from massive volume change and poor cycling performance.To clarify the dynamic chemical and microstructural evolution of Sn anode during lithiation and delithiation,synchrotron X-ray energydispersive diffraction and X-ray tomography are simultaneously employed during Li/Sn cell operation.The intermediate Li-Sn alloy phases during de/lithiation are identified,and their dynamic phase transformation is unraveled which is further correlated with the volume variation of the Sn at particle-and electrode-level.Moreover,we find that the Sn particle expansion/shrinkage induced particle displacement is anisotropic:the displacement perpendicular to the electrode surface(z-axis)is more pronounced compared to the directions(x-and y-axis)along the electrode surface.This anisotropic particle displacement leads to an anisotropic volume variation at the electrode level and eventually generates a net electrode expansion towards the separator after cycling,which could be one of the root causes of mechanical detachment and delamination of electrodes during long-term operation.The unraveled chemical evolution of Li-Sn and deep insights into the microstructural evolution of Sn anode provided here could guide future design and engineering of Sn and other alloy anodes for high energy density Li-and Na-ion batteries.
