中国科学院机构知识库网格系统: 检索

浏览/检索结果: 共5条，第1-5条

帮助

条数/页：排序方式：
	MGRG-morphological gradient based 3D region growing algorithm for airway tree segmentation in image guided intervention therapy (EI CONFERENCE) 会议论文 OAI收割 2nd International Symposium on Bioelectronics and Bioinformatics, ISBB 2011, November 3, 2011 - November 5, 2011, Suzhou, China 作者: Zhang T.; Gao X. 收藏 \| 浏览/下载：45/0 \| 提交时间：2013/03/25 Accurate surgical planning and guidance plays an important role in successful implementation of image guided intervention. In interventional lung cancer diagnosis and treatments precise segmentation of airway trees from lung CT images provides crucial visualization for preoperative planning and intraoperative guidance to avoid major trachea injury. While 3D region growing can segment main the parts of an airway tree (trachea left and right main bronchus as well as bronchi) the method fails at bronchiole segmentation and is not robust. Mathematical morphology is an anatomical detective. In this paper we propose a morphological gradient based region growing (MGRG) algorithm to overcome the intensity inhomogeneity and improve the robustness of 3D region growing on extraction of bronchioles. The MGRG algorithm is validated using lung CT images and results show that it is able to segment bronchioles and outperforms the traditional region growing method on airway tree segmentation. 2011 IEEE.
	Nonlinear control design for system with mechanical resonance based on two tracking-differentiators (EI CONFERENCE) 会议论文 OAI收割 2010 IEEE International Conference on Mechatronics and Automation, ICMA 2010, August 4, 2010 - August 7, 2010, Xi'an, China 作者: Li J.; Li Y.; Li Y.; Li Y.; Li Y. 收藏 \| 浏览/下载：22/0 \| 提交时间：2013/03/25 A nonlinear control strategy for controlling a motion system with mechanical resonance is presented in this paper. A mathematical model of the servo system is derived according to the parameters of an actual system. By using two Tracking-Differentiators reference input and system output are tracked and their differential signals are given simultaneously. A nonlinear PD control law in velocity loop is designed based on non-smooth feedback. The simulation results show that the control law is superior remarkably in performance to linear PD control law and the classical PID control law. Tracking-Differentiator resolves the contradiction between rapidity and overshoot of system response. The nonlinear PD control law improves system dynamic performance and intensifies the ability of disturbance rejection. The control design achieved in this paper makes the servo system more robust. 2010 IEEE.
	An efficient discrete particle swarm algorithm for task assignment problems (EI CONFERENCE) 会议论文 OAI收割 2009 IEEE International Conference on Granular Computing, GRC 2009, August 17, 2009 - August 19, 2009, Nanchang, China 作者: Wang C. 收藏 \| 浏览/下载：14/0 \| 提交时间：2013/03/25 Task Assignment Problems (TAPs) in distributed computer system are general NP-hard and usually modeled as integer programming discrete problems. Many algorithms are proposed to resolve those problems. Discrete particle swarm algorithm (DPS) is a newly developed method to solve constraint satisfaction problem (CSP) which has advantage on search capacity and can find more solutions. We proposed an improved DPS to solve TAP in this paper. DPS has a special operator namely coefficient multiplying speed which is designed for CSP but does not exist in other discrete problems. Thus we redefined a coefficient multiplying speed operator with probability selection. We analyzed the speed and position updating formula then we derived a refined position updating formula. Several experiments are carried out to test our DPS. Experimental results show that our algorithm has more efficient search capacity higher success rate less running time and more robust.
	Algorithm research of flexible graphplan based on heuristic (EI CONFERENCE) 会议论文 OAI收割 9th International Conference for Young Computer Scientists, ICYCS 2008, November 18, 2008 - November 21, 2008, Zhang Jia Jie, Hunan, China 作者: Xu S.; Wang X.; Wang X.; Wang X.; Sun Y. 收藏 \| 浏览/下载：20/0 \| 提交时间：2013/03/25 Classic Graphplan has too much restriction on capturing the full subtlety of many real problems. Flexible Graphplan is defined which supports the soft constraints often found in reality. Heuristic concept is introduced to the process of plan extraction in flexible graphplan in order to improve the efficiency of plan extraction and the quality of plan. A novel algorithm using the new heuristic function which is applied by improved sum mutex heuristic to deal with planning problems is proposed. Sum mutex heuristic which is in common use as heuristic function takes into account only static propositional mutexes and ignores the mutexes of actions. The performance of the new algorithm on many benchmark problems is remarkably robust. It can solve many planning problems which can't be solved by the heuristic state space search planning system using sum mutex heuristic. 2008 IEEE.
	A novel starting-point-independent wavelet coefficient shape matching (EI CONFERENCE) 会议论文 OAI收割 ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China Hu S.; Zhu M.; Wu C.; Song H.-J. 收藏 \| 浏览/下载：18/0 \| 提交时间：2013/03/25 In many computer vision tasks in order to improve the accuracy and robustness to the noise wavelet analysis is preferred for the natural multi-resolution property. However the wavelet representation suffers from the dependency of the starting point of the sampled contour. For overcoming the problem that the wavelet representation depends on the starting point of the sampled contour the Zernike moments are introduced and a novel Starting-Point-lndependent wavelet coefficient shape matching algorithm is presented. The proposed matching algorithm firstly gains the object contours and give the translation and scale invariant object shape representation. The object shape representation is converted to the dyadic wavelet representation by the wavelet transform. And then calculate the Zernike moments of wavelet representation in different scales. With respect to property of rotation invariant of Zernike moments consider the Zernike moments as the feature vector to calculate the dissimilarity between the object and template image which overcoming the problem of dependency of starting point. The experimental results have proved the proposed algorithm to be efficient precise and robust.