为了进一步扩展网络视频市场,并在确保用户体验的基础上,增加各大网络视频商家的利益,本文以网络视频直播架构作为主要研究对象,通过对视频直播流媒体技术进行分析,在结合传统视频直播架构的基础上,对基于Flash Media Server技术的低成...为了进一步扩展网络视频市场,并在确保用户体验的基础上,增加各大网络视频商家的利益,本文以网络视频直播架构作为主要研究对象,通过对视频直播流媒体技术进行分析,在结合传统视频直播架构的基础上,对基于Flash Media Server技术的低成本视频直播架构展开了深入研究。展开更多
Security issues are always difficult to deal with in mobile ad hoe networks. People seldom studied the costs of those security schemes respectively and for some security methods designed and adopted beforehand, their ...Security issues are always difficult to deal with in mobile ad hoe networks. People seldom studied the costs of those security schemes respectively and for some security methods designed and adopted beforehand, their effects are often investigated one by one. In fact, when facing certain attacks, different methods would respond individually and result in waste of resources. Making use of the cost management idea, we analyze the costs of security measures in mobile ad hoc networks and introduce a security framework based on security mechanisms cost management. Under the framework, the network system＇s own tasks can be finished in time and the whole network＇s security costs can be decreased. We discuss the process of security costs computation at each mobile node and in certain nodes groups. To show how to use the proposed security framework in certain applications, we give examples of DoS attacks and costs computation of defense methods. The results showed that more secure environment can be achieved based on the security framework in mobile ad hoc networks.展开更多
A runtime reconfigurable very-large-scale integration （VLSI） architecture for image and video scaling by arbitrary factors with good antialiasing performance is presented in this paper. Video scal- ing is used in a ...A runtime reconfigurable very-large-scale integration （VLSI） architecture for image and video scaling by arbitrary factors with good antialiasing performance is presented in this paper. Video scal- ing is used in a wide range of applications from broadcast, medical imaging and high-resolution video effects to video surveillance, and video conferencing. Many algorithms have been proposed for these applications, such as piecewise polynomial kernels and windowed sinc kernels. The sum of three shifted versions of a B-spline function, whose weights can be adjusted for different applications, is adopted as the main filter. The proposed algorithm is confirmed to be effective on image scaling ap- plications and also verified by many widely acknowledged image quality measures. The reconfigu- rable hardware architecture constitutes an arbitrary scaler with low resource consumption and high performance targeted for field programmable gate array （FPGA） devices. The scaling factor can be changed on-the-fly, and the filter can also be changed during runtime within a unifying framework.展开更多
Partial Reconfigurable FPGAs （Field Programmable Gate Array） allow tasks to be placed and removed dynamically at runtime. One of the challenging problems is the placement of modules on reconfigurable resources. Seve...Partial Reconfigurable FPGAs （Field Programmable Gate Array） allow tasks to be placed and removed dynamically at runtime. One of the challenging problems is the placement of modules on reconfigurable resources. Several modules placement techniques have been introduced in the literature to solve the temporal placement problem. This paper presents a temporal placement approach that manages the resources of a reconfigurable device. In fact, the authors＇ contribution focuses on introducing a new temporal placement algorithm that aims to minimize the communication cost between modules. Results show an important improvement in communication cost compared with other approaches.展开更多
文摘Security issues are always difficult to deal with in mobile ad hoe networks. People seldom studied the costs of those security schemes respectively and for some security methods designed and adopted beforehand, their effects are often investigated one by one. In fact, when facing certain attacks, different methods would respond individually and result in waste of resources. Making use of the cost management idea, we analyze the costs of security measures in mobile ad hoc networks and introduce a security framework based on security mechanisms cost management. Under the framework, the network system＇s own tasks can be finished in time and the whole network＇s security costs can be decreased. We discuss the process of security costs computation at each mobile node and in certain nodes groups. To show how to use the proposed security framework in certain applications, we give examples of DoS attacks and costs computation of defense methods. The results showed that more secure environment can be achieved based on the security framework in mobile ad hoc networks.
基金Supported by the National Natural Science Foundation of China(No.60972126)the Joint Funds of the National Natural Science Foundation of China(No.U0935002/L05)+1 种基金the Beijing Municipal Natural Science Foundation(No.4102060)the State Key Program of the National Natural Science of China(No.61032007)
文摘A runtime reconfigurable very-large-scale integration （VLSI） architecture for image and video scaling by arbitrary factors with good antialiasing performance is presented in this paper. Video scal- ing is used in a wide range of applications from broadcast, medical imaging and high-resolution video effects to video surveillance, and video conferencing. Many algorithms have been proposed for these applications, such as piecewise polynomial kernels and windowed sinc kernels. The sum of three shifted versions of a B-spline function, whose weights can be adjusted for different applications, is adopted as the main filter. The proposed algorithm is confirmed to be effective on image scaling ap- plications and also verified by many widely acknowledged image quality measures. The reconfigu- rable hardware architecture constitutes an arbitrary scaler with low resource consumption and high performance targeted for field programmable gate array （FPGA） devices. The scaling factor can be changed on-the-fly, and the filter can also be changed during runtime within a unifying framework.
文摘Partial Reconfigurable FPGAs （Field Programmable Gate Array） allow tasks to be placed and removed dynamically at runtime. One of the challenging problems is the placement of modules on reconfigurable resources. Several modules placement techniques have been introduced in the literature to solve the temporal placement problem. This paper presents a temporal placement approach that manages the resources of a reconfigurable device. In fact, the authors＇ contribution focuses on introducing a new temporal placement algorithm that aims to minimize the communication cost between modules. Results show an important improvement in communication cost compared with other approaches.
