为解决柔性车间内AGV的面对动态障碍物时路径规划不准确的问题,基于位操作方法提出一种跳点搜索(Jump Point Search, JPS)的改进算法。算法采用二进制方式编码化栅格地图,实现障碍物的快速识别;通过位操作方法扩大剪枝规则的应用范围,提...为解决柔性车间内AGV的面对动态障碍物时路径规划不准确的问题,基于位操作方法提出一种跳点搜索(Jump Point Search, JPS)的改进算法。算法采用二进制方式编码化栅格地图,实现障碍物的快速识别;通过位操作方法扩大剪枝规则的应用范围,提升JPS算法中搜寻节点的效率;引入Octile距离模式对算法的启发式函数进行优化,达到降低计算复杂度,提升规划速度目的。分别将改进JPS算法与A*算法、JPS算法进行实验对比,结果表明:在复杂车间环境中,搜索时间、扩展节点数量、规划的路径同比其它两种算法都具有明显优势;在躲避动态障碍物测试中,改进型算法避障成功率为92%,躲避成功次数最高且规划的路径质量最优,同比两种算法综合性能最优。验证了算法的可行性。展开更多
A new method is presented for the segmentation of pulmonary parenchyma. The proposed method is based on the area calculation of different objects in the image. The main purpose of the proposed algorithm is the segment...A new method is presented for the segmentation of pulmonary parenchyma. The proposed method is based on the area calculation of different objects in the image. The main purpose of the proposed algorithm is the segment of the lungs images from the computer tomography(CT) images. The original image is binarized using the bit-plane slicing technique and among the different images the best binarized image is chosen. After binarization, the labeling is done and the area of each label is calculated from which the next level of binarized image is obtained. Then, the boundary tracing algorithm is applied to get another level of binarized image. The proposed method is able to extract lung region from the original images. The experimental results show the significance of the proposed method.展开更多
This paper proposes an optimal solution to choose the number of enhancement layers in fine granularity scalability (FGS) scheme under the constraint of minimum transmission energy, in which FGS is combined with transm...This paper proposes an optimal solution to choose the number of enhancement layers in fine granularity scalability (FGS) scheme under the constraint of minimum transmission energy, in which FGS is combined with transmission energy control, so that FGS enhancement layer transmission energy is minimized while the distortion guaranteed. By changing the bit-plane level and packet loss rate, minimum transmission energy of enhancement layer is obtained, while the expected distortion is satisfied.展开更多
Bit-plane decomposition makes images obtain a number of layers. According to the amount of data information, images are encrypted, and the paper proposes image encryption method with Chaotic Mapping based on multi-lay...Bit-plane decomposition makes images obtain a number of layers. According to the amount of data information, images are encrypted, and the paper proposes image encryption method with Chaotic Mapping based on multi-layer parameter disturbance. The advantage of multi-layer parameter disturbance is that it not only scrambles pixel location of images, but also changes pixel values of images. Bit-plane decomposition can increase the space of key. And using chaotic sequence generated by chaotic system with different complexities to encrypt layers with different information content can save operation time. The simulation experiments show that using chaotic mapping in image encryption method based on multi-layer parameter disturbance can cover plaintext effectively and safely, which makes it achieve ideal encryption effect.展开更多
文摘为解决柔性车间内AGV的面对动态障碍物时路径规划不准确的问题,基于位操作方法提出一种跳点搜索(Jump Point Search, JPS)的改进算法。算法采用二进制方式编码化栅格地图,实现障碍物的快速识别;通过位操作方法扩大剪枝规则的应用范围,提升JPS算法中搜寻节点的效率;引入Octile距离模式对算法的启发式函数进行优化,达到降低计算复杂度,提升规划速度目的。分别将改进JPS算法与A*算法、JPS算法进行实验对比,结果表明:在复杂车间环境中,搜索时间、扩展节点数量、规划的路径同比其它两种算法都具有明显优势;在躲避动态障碍物测试中,改进型算法避障成功率为92%,躲避成功次数最高且规划的路径质量最优,同比两种算法综合性能最优。验证了算法的可行性。
基金supported (in part) by research funding from Chosun University, Korea, 2013
文摘A new method is presented for the segmentation of pulmonary parenchyma. The proposed method is based on the area calculation of different objects in the image. The main purpose of the proposed algorithm is the segment of the lungs images from the computer tomography(CT) images. The original image is binarized using the bit-plane slicing technique and among the different images the best binarized image is chosen. After binarization, the labeling is done and the area of each label is calculated from which the next level of binarized image is obtained. Then, the boundary tracing algorithm is applied to get another level of binarized image. The proposed method is able to extract lung region from the original images. The experimental results show the significance of the proposed method.
文摘This paper proposes an optimal solution to choose the number of enhancement layers in fine granularity scalability (FGS) scheme under the constraint of minimum transmission energy, in which FGS is combined with transmission energy control, so that FGS enhancement layer transmission energy is minimized while the distortion guaranteed. By changing the bit-plane level and packet loss rate, minimum transmission energy of enhancement layer is obtained, while the expected distortion is satisfied.
文摘Bit-plane decomposition makes images obtain a number of layers. According to the amount of data information, images are encrypted, and the paper proposes image encryption method with Chaotic Mapping based on multi-layer parameter disturbance. The advantage of multi-layer parameter disturbance is that it not only scrambles pixel location of images, but also changes pixel values of images. Bit-plane decomposition can increase the space of key. And using chaotic sequence generated by chaotic system with different complexities to encrypt layers with different information content can save operation time. The simulation experiments show that using chaotic mapping in image encryption method based on multi-layer parameter disturbance can cover plaintext effectively and safely, which makes it achieve ideal encryption effect.
