目前软件定义网络(software defined network,SDN)多控制器管理的研究重点和难点在于多控制器部署,合适的控制器数目和合理的部署位置能够实现低延迟和高可靠性的折中。在网络拓扑图上将部署位置问题简化并形式化,定义了可靠性和延迟指...目前软件定义网络(software defined network,SDN)多控制器管理的研究重点和难点在于多控制器部署,合适的控制器数目和合理的部署位置能够实现低延迟和高可靠性的折中。在网络拓扑图上将部署位置问题简化并形式化,定义了可靠性和延迟指标,设计了多控制器部署位置求解算法(multi-controller placement location algorithm,MCP)。MCP通过遗传算法将网络划分为多个子网,并在每个子网中放置一个控制器,以最大化网络可靠性和最小化路径延迟为目标,通过模拟退火算法确定控制器在每个子网中的位置,经对比实验验证了MCP生成的部署位置方案在可靠性和延迟上的性能优势。以可靠性和延迟为评估指标,基于MCP测试了各种网络规模的最合适控制器数目,并分析得出最合适控制器数目与网络规模之间的统计规律。展开更多
X-ray luminescence computed tomography(XLCT) is an emerging hybrid imaging modality that can be used as a new tool in molecular imaging. XLCT has the potential to achieve the high spatial resolution of X-ray imaging a...X-ray luminescence computed tomography(XLCT) is an emerging hybrid imaging modality that can be used as a new tool in molecular imaging. XLCT has the potential to achieve the high spatial resolution of X-ray imaging and the high sensitivity feature of optical imaging in deep tissues. In XLCT,high energy X-ray photons are used to excite X-ray excitable particles emitting optical photons to be measured for reconstruction of the particle distribution inside tissues. Numerical simulations and experimental studies have been performed and proved that XLCT is suitable for in vivo small animal imaging. The aim of this review paper is to introduce the background of XLCT and to detail the concept of XLCT,including a brief review of tw o types of XLCT imaging system designs. The major challenges in the development of XLCT are also described. Finally,the future applications and development directions of XLCT are discussed.展开更多
基金partially supported by Grant (R03 EB022305) from the National Institute of Health (NIH)Start-up fund from UC Merced
文摘X-ray luminescence computed tomography(XLCT) is an emerging hybrid imaging modality that can be used as a new tool in molecular imaging. XLCT has the potential to achieve the high spatial resolution of X-ray imaging and the high sensitivity feature of optical imaging in deep tissues. In XLCT,high energy X-ray photons are used to excite X-ray excitable particles emitting optical photons to be measured for reconstruction of the particle distribution inside tissues. Numerical simulations and experimental studies have been performed and proved that XLCT is suitable for in vivo small animal imaging. The aim of this review paper is to introduce the background of XLCT and to detail the concept of XLCT,including a brief review of tw o types of XLCT imaging system designs. The major challenges in the development of XLCT are also described. Finally,the future applications and development directions of XLCT are discussed.
