为了更有效地降低滤波器组多载波(filter bank multicarrier,FBMC)系统过高的峰均功率比(peak-to-average power ratio,PAPR),在部分传输序列(partial transfer sequence,PTS)方法的基础上提出了多随机分割算法,该算法通过选用合适的子...为了更有效地降低滤波器组多载波(filter bank multicarrier,FBMC)系统过高的峰均功率比(peak-to-average power ratio,PAPR),在部分传输序列(partial transfer sequence,PTS)方法的基础上提出了多随机分割算法,该算法通过选用合适的子块数分割方法来降低系统的复杂度,同时兼顾了随机分割法的优越性。此外,根据其在分割顺序上的特点,可以进一步提高系统的性能。通过仿真试验验证了新算法的有效性。展开更多
受GNSS硬件设备、通讯链路以及观测环境等因素影响,GNSS位移监测数据往往包含粗差,无法反映真实的变形特征。针对该问题,本文提出将稳健随机分割森林(robust random cut forest,RRCF)算法应用于GNSS位移监测数据粗差实时检测。仿真数据...受GNSS硬件设备、通讯链路以及观测环境等因素影响,GNSS位移监测数据往往包含粗差,无法反映真实的变形特征。针对该问题,本文提出将稳健随机分割森林(robust random cut forest,RRCF)算法应用于GNSS位移监测数据粗差实时检测。仿真数据处理结果表明,RRCF算法粗差实时检测的准确率、精确率与召回率分别优于95%、98%、96%。地质灾害位移监测数据处理结果表明,GNSS位移监测数据发生异常突变时,RRCF方法检测结果与实际异常值情况吻合且误判率较低。总体而言,RRCF算法对GNSS位移监测数据异常实时检测的准确率和可用性均较好。展开更多
This paper is to detect regions (objects) boundaries, also to isolate and extract individual components from a medical image. This can be done using an active contours to detect regions in a given image, based on tech...This paper is to detect regions (objects) boundaries, also to isolate and extract individual components from a medical image. This can be done using an active contours to detect regions in a given image, based on techniques of curve evolution, Mumford Shah functional for segmentation and level sets. The paper classified the images into different intensity regions based on Markov random field, then detected regions whose boundaries are not necessarily defined by gradient by minimizing an energy of Mumford Shah functional for segmentation which can be seen as a particular case of the minimal partition problem. In the level set formulation, the problem becomes a mean curvature flow like evolving the active contour, which will stop on the desired boundary. The stopping term does not depend on the gradient of the image, as in the classical active contour and the initial curve of level set can be anywhere in the image, and interior contours are automatically detected. The final image segmentation is one closed boundary per actual region in the image.展开更多
文摘为了更有效地降低滤波器组多载波(filter bank multicarrier,FBMC)系统过高的峰均功率比(peak-to-average power ratio,PAPR),在部分传输序列(partial transfer sequence,PTS)方法的基础上提出了多随机分割算法,该算法通过选用合适的子块数分割方法来降低系统的复杂度,同时兼顾了随机分割法的优越性。此外,根据其在分割顺序上的特点,可以进一步提高系统的性能。通过仿真试验验证了新算法的有效性。
文摘受GNSS硬件设备、通讯链路以及观测环境等因素影响,GNSS位移监测数据往往包含粗差,无法反映真实的变形特征。针对该问题,本文提出将稳健随机分割森林(robust random cut forest,RRCF)算法应用于GNSS位移监测数据粗差实时检测。仿真数据处理结果表明,RRCF算法粗差实时检测的准确率、精确率与召回率分别优于95%、98%、96%。地质灾害位移监测数据处理结果表明,GNSS位移监测数据发生异常突变时,RRCF方法检测结果与实际异常值情况吻合且误判率较低。总体而言,RRCF算法对GNSS位移监测数据异常实时检测的准确率和可用性均较好。
文摘This paper is to detect regions (objects) boundaries, also to isolate and extract individual components from a medical image. This can be done using an active contours to detect regions in a given image, based on techniques of curve evolution, Mumford Shah functional for segmentation and level sets. The paper classified the images into different intensity regions based on Markov random field, then detected regions whose boundaries are not necessarily defined by gradient by minimizing an energy of Mumford Shah functional for segmentation which can be seen as a particular case of the minimal partition problem. In the level set formulation, the problem becomes a mean curvature flow like evolving the active contour, which will stop on the desired boundary. The stopping term does not depend on the gradient of the image, as in the classical active contour and the initial curve of level set can be anywhere in the image, and interior contours are automatically detected. The final image segmentation is one closed boundary per actual region in the image.
