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MR T1 Image Segmentation of a Prostate Based on Distance Regularized Level Set Evolution
Yong-de Zhang,Jing-chun Peng,Gang Liu,Jin-gang Jiang,Yan-jiang Zhao 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.7
Prostate segmentation from MRI is a necessary first step and plays an important role in clinical decision making process. A MR T1 Image segmentation method of the prostate based on distance regularized level set evolution (DRLSE) is proposed. To smooth the prostate image to reduce the noise, a preprocessed prostate image with Gaussian kernel and get an edge indicator is convolved. We construct an energy function with a distance regularization term and an external energy term containing the edge indicator and minimize it by solving the gradient flow which can be implemented with a finite difference scheme. In segmentation experiments, the impact of parameters λ , μ , α and ε in DRLSE model on the image segmentation is analyzed, and an optimal value of these parameters is given. The experiment results confirm the effectiveness of the MRI segmentation method of prostate for different situation of different patients.
Study on Springback Properties of Different Orthodontic Archwires in Archwire Bending Process
Jiang Jin-gang,Wang Zhao,Zhang Yong-de,Jiang Ji-xiong,Niu Suo-liang,Liu Yi 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.12
The archwire bending is one of processes the most frequently used in the orthodontic treatment. Furthermore, the springback of sheet metal, which is defined as elastic recovery of the part during unloading, should be taken into consideration so as to produce formed archwire within acceptable tolerance limits. In this paper, the springback angle of different alloy archwires (including NiTi alloy wire, Beta-Ti alloy wires, Chinese stainless steel wires, and Australian stainless steel wires) were performed by the theoretical calculation based on large deformation theory and the finite element analysis. A series of numerical simulations has been conducted for the bending test, which physically simulates the actual bending of alloy archwire with a robotic apparatus. The finite element analysis of springback is shown to be very consistent with the theoretical calculation results.
Research on the Automatic Assessment System for the Ship Handling Simulator
De-Long Wang,Hong-Xiang Ren,Jin-Gang Yin 국제이네비해양경제학회 2023 International Journal of e-Navigation and Maritime Vol.20 No.-
At present, the assessment for the crew training using the ship handling simulator is completed by the assessor, which is subjective and difficult to unify the assessment criteria. Under this assessment mode, the assessor will have a great work intensity. So it is necessary to design and develop the automatic assessment system for the ship handling simulator. This paper introduces the automatic assessment system developed by Dalian Maritime University (shorted for DMU), which includes the assessment method, system architecture and implementation. A selected example of applications is described.
Workspace analysis of 3-CPS parallel micro-manipulator for mirror active adjusting platform
Gang Cheng,Bing-jing Qiu,De-hua Yang,Hou-guang Liu 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.12
In order to adjust telescope mirrors with high precision, a 3 cylindrical-prismatic-spherical (CPS) parallel micro-manipulator with 6 degrees-of-freedom (DOF) and partial decoupling is proposed. Structure characteristics of the micro-manipulator were analyzed and the kinematic equations were derived based on Euler method. To avoid tedious derivation, Jacobian matrix with screw theory representing the input and output relation of micro-manipulator is established by using velocity influence coefficient method. Combining topological structure characteristics of the 3-CPS parallel micro-manipulator, the solving procedures of workspace are obtained. Moreover, the position workspace with a given orientation and the orientation workspace with a given translation position are constructed by numerical simulations. The workspace range is chosen as the optimization goal of structure parameters, and the circumcircle radius ratio of base and moving platform and the lengths of each sub-link are optimized. The maximum condition number and the minimum singular value are chosen as the precision indexes to analyze the precision performance of the workspace. Then, the properties of the position workspaces with various orientations and the orientation workspaces with various positions are simulated numerically, and the simulation results prove that the 3-CPS parallel micro-manipulator has an ability to achieve high precision operations. This research provides a workspace modeling and optimization method for the practical application in telescope mirror adjustment or other fields requiring high precision.
Jiao, De-Chao,Zhou, Qi,Han, Xin-Wei,Wang, Ya-Feng,Wu, Gang,Ren, Jian-Zhuang,Wang, Yan-Li,Ding, Peng-Xu,Ma, Ji,Fu, Ming-Ti Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.2
To evaluate efficacy of microwave ablation in a primary clinical study, sixty patients (44 men, 16 women; mean age 53 years) with 96, 1-8 cm (mean $3.20{\pm}0.17$ cm) liver cancers were treated with 2,450-MHz internally cooled-shaft antenna. Complete ablation (CA) and local tumor progression (LTP) rates as well as complications were determined. CA rates in small (< 3.0 cm), intermediate (3.1-5.0 cm) and large (5.1-8.0 cm) liver cancers were 96.4% (54/56), 92.3% (24/26) and 78.6% (11/14), respectively. During a mean follow-up period of $17.17{\pm}6.52$ months, LTP occurred in five (5.21%) treated cases. There was no significant difference in the CA and LTP rates between the HCC and liver metastasis patient subgroups (P<0.05). Microwave ablation provides a reliable, efficient, and safe technique to perform hepatic tumor ablation.
Effect of single-pulse laser irradiation energy on healing fatigue damage for copper film
Chong-Gang Ren,De-Guang Shang,Lu Wang,Yu-Bo Guo 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.4
In this study, the optimum laser process parameter was determined by fatigue experiment for the treated copper film specimens withthickness of 25 μm. The mechanism of healing fatigue damage was analyzed by the numerical simulation of temperature field induced bylaser irradiation and the microstructure changes on the surface of specimens. The results showed that the fatigue damage of copper filmspecimens can be healed when the applied energy density is in the range from 4×10³J/m² to14×10³ J/m², and the fatigue life can increaseby about 5 times when the applied energy density is 7×10³ J/m². The process hardening and grain refinement in the surface layer aremainly responsible for extending fatigue life.
Jiao, De-Chao,Han, Xin-Wei,Wu, Gang,Ren, Jian-Zhuang Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.17
Background: To explored the value of 3D C-arm CT (CACT) guidance system in performing radiofrequency ablation (RFA) following transarterial chemoembolizationon (TACE) for hepatocellular carcinomas. Materials and Methods: RFA of hepatocellular carcinomas (HCC) were performed on 15 patients (21 lesions) with the assistance of CACT guidance system. Technical success, procedure time, complications and patient radiation exposure were investigated. The puncture performance level was evaluated on a five-point scale (5-1: excellent-poor). Complete ablation rate was evaluated after two months follow-up using enhanced CT scans. Results: The technical success rate of RFA procedure under CACT navigation system was 100 %. Mean total procedure time was $24.24{\pm}6.53min$, resulting in a mean effective exposure dose of $15.4{\pm}5.1mSv$. The mean puncture performance level rated for CACT guided RFA procedure was $4.87{\pm}0.35$. Complete ablation (CA) was achieved in 20 (95.2%) of the treated 21 tumors after the first RFA session. None of patients developed intra-procedural complications. Conclusions: 3D CACT guidance system enables reliable and efficient needle positioning by providing real-time intraoperative guidance for performing RFA on HCCs.