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Estimation of deformed laser heat sources and thermal analysis on laser assisted turning of square member

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Journal of Central South University 2012年第2期19卷 402-407页

作者： KIM Jae-hyun KIM Kwang-sun CHOI Jun-young LEE Choon-man department of Mechanical design and Manufacturing engineering Changwon National University

Laser assisted machining （LAM） has difficulties in estimating temperature after applying a LAM process due to its very small heat input area, large energy and movement. In particular, in the case of laser assisted turning （LAT） process, it is more difficult to estimate the temperature after preheating because it has a shape of ellipse when a laser heat source is rotated. A prediction method and thermal analysis method for heat source shapes were proposed as a square shaped member was preheated. The temperature distribution was calculated according to the rotation of the member. Compared with the results of the former study, the maximum temperature of the calculation results, 1 407.1 ℃, is 8.5 ℃ higher than that of the square member, which is 1 398.6 ℃. In a LAT process for a square member, the maximum temperature is 1 850.8 ℃. It is recognized that a laser power control process is required because square members show a maximum temperature that exceeds a melting temperature at around a vertex of the member according to the rotation.

关键词： laser assisted machining laser assisted turning laser preheating laser power control

Optimal rotor wear design in hypotrochoidal gear pump using genetic algorithm

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Journal of Central South University 2011年第3期18卷 718-725页

作者： KWON Soon-man KIM Chang-Hyun SHIN Joong-ho department of Mechanical design and Manufacturing engineering Changwon National University

The wear rate between the rotors of a hypotrochoidal gear pump is *** the knowledge of shape design on the rotors,the contact stresses without hydrodynamic effect between the rotor teeth were evaluated through the calculation of the Hertzian contact *** on the above results and the sliding velocity between the rotors,a genetic algorithm (GA) was used as an optimization technique forminimizing the wear rate proportional factor (WRPF).The result shows that the wear rate or the WRPF can be reduced considerably,*** 12.8%,throughout the optimization using GA.

关键词： gerotor hypotrochoidal gear pump Hertzian contact stress wear rate proportional factor genetic algorithm

Lightweight design of 45000r/min spindle using full factorial design and extreme vertices design methods

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Journal of Central South University 2011年第1期18卷 153-158页

作者： PARK Seong-jin LEE Choon-man HWANG Young-kug department of Mechanical design and Manufacturing engineering Changwon National University

Factors for determining the spindle size are the shaft diameter, positions of bearing and motor, and entire length of the spindle. Then, it is important to find the assembling of the optimal design variables, which satisfy the stiffimss and rotational speed required to the spindle. A general full factorial design method was used to verify some factors that affect the natural frequency of a spindle. It is verified that the shorter shaft length and bearing span length represent the higher natural frequency, and there are some effects according to the change in the levels of factors. The detailed spindle dimension is determined by applying an EVD method, which can define the optimal bearing position through considering the limiting condition. Based on the estimated regression model, the optimal spindle size and bearing distance that can improve the primary natural frequency are obtained, and the influence of design factors on the natural frequency is also analyzed.

关键词： high-speed spindle extreme vertices design natural frequency lightweight design full factorial design

Wearability of Copper Ion Complex Bamboo Pulp Knitted Fabrics with Chitosan Pretreatment

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Journal of Donghua University(English Edition) 2016年第4期33卷 632-636页

作者：陈莹徐刚王鸿达唐劲天 department of Material Science and engineering Beijing Institute of Fashion Technology Institute of Medical Physics and engineering Department of Engineering PhysicsTsinghua University College of Textile and fashion Qingdao University

Wearability is one of important factors for the textile product quality. The wearability of bamboo pulp knitted fabrics was mainly discussed which were treated with chitosan and cupper ammonia solution. Tensile and bursting properties, abrasion resistance,drapability,air permeability,moisture-penetrability and warmth retention properties of fabrics were tested to investigate the changes. The results showed that chitosan pretreatment improved the tensile and bursting strengths,abrasion resistance and moisture penetrability,but decreased the drapability and air *** ammonia solution treatments decreased the tensile and bursting strengths,abrasion resistance and air permeability,but increased the drapability, moisture penetrability and warmth retention properties.

关键词： retention ammonia pretreatment chitosan permeability fabrics moisture bamboo Bamboo tensile

design of face-hobbed spiral bevel gears with reduced maximum tooth contact pressure and transmission errors

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Chinese Journal of Aeronautics 2013年第3期26卷 777-790页

作者： Vilmos Simon Budapest University of Technology and Economics Faculty of Mechanical Engineering Department for Machine Design

The aim of this study is to define optimal tooth modifications, introduced by appropriately chosen head-cutter geometry and machine tool setting, to simultaneously minimize tooth contact pressure and angular displacement error of the driven gear （transmission error） of face-hobbed spiral bevel gears. As a result of these modifications, the gear pair becomes mismatched, and a point contact replaces the theoretical line contact. In the applied loaded tooth contact analysis it is assumed that the point contact under load is spreading over a surface along the whole or part of the ‘‘potential’’ contact line. A computer program was developed to implement the formulation provided above. By using this program the influence of tooth modifications introduced by the variation in machine tool settings and in head cutter data on load and pressure distributions, transmission errors, and fillet stresses is investigated and discussed. The correlation between the ease-off obtained by pinion tooth modifications and the corresponding tooth contact pressure distribution is investigated and the obtained results are presented.

关键词： Ease-off Face-hobbed spiral bevel gears Load distribution Transmission errors Gear teeth

Exploring Local Regularities for 3D Object Recognition

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Chinese Journal of Mechanical engineering 2016年第6期29卷 1104-1113页

作者： TIAN Huaiwen QIN Shengfeng College of Mechanical engineering Southwest Jiaotong University department of design Northumbria University

In order to find better simplicity measurements for 3D object recognition, a new set of local regularities is developed and tested in a stepwise 3D reconstruction method, including localized minimizing standard deviation of angles（L-MSDA）, localized minimizing standard deviation of segment magnitudes（L-MSDSM）, localized minimum standard deviation of areas of child faces （L-MSDAF）, localized minimum sum of segment magnitudes of common edges （L-MSSM）, and localized minimum sum of areas of child face （L-MSAF）. Based on their effectiveness measurements in terms of form and size distortions, it is found that when two local regularities： L-MSDA and L-MSDSM are combined together, they can produce better performance. In addition, the best weightings for them to work together are identified as 10% for L-MSDSM and 90% for L-MSDA. The test results show that the combined usage of L-MSDA and L-MSDSM with identified weightings has a potential to be applied in other optimization based 3D recognition methods to improve their efficacy and robustness.

关键词： stepwise 3D reconstruction localized regularities 3D object recognition polyhedral objects line drawing

A Novel Separability Objective Function in CNN for Feature Extraction of SAR Images

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Chinese Journal of Electronics 2019年第2期28卷 423-429页

作者： GAO Fei WANG Meng WANG Jun YANG Erfu ZHOU Huiyu department of Electronic and Information engineering Beihang University department of design Manufacture and Engineering Management (DMEM) University of Strathclyde department of Informatics University of Leicester

Convolutional neural network(CNN) has become a promising method for Synthetic aperture radar(SAR) target recognition. Existing CNN models aim at seeking the best separation between classes, but rarely care about the separability of them. We performs a separability measure by analyzing the property of linear separability, and proposes an objective function for CNN to extract linearly separable features. The experimental results indicate the output features are linearly separable,and the classification results are comparable with the other state of the art techniques.

关键词： Synthetic aperture radar(SAR) Convolution neural network(CNN) Classification Linear separability Objective function

Wearing Comfort of Women's Pantyhose in Winter

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Journal of Donghua University(English Edition) 2016年第4期33卷 637-639页

作者：赵蒙蒙李俊李艳梅林若昀 fashion College Shanghai University of Engineering Science Protective Clothing Research Center Fashion InstituteDonghua University Key Laboratory of Clothing design and Technology Donghua University

The wearing comfort of clothing has been frequently investigated,but there are few researches on the wearing comfort of pantyhose. This study first carried out a questionnaire survey on female consumers to know about their preference and demand on pantyhose. Then thermal manikin test and subject wearing trials were performed to evaluate the commonly used pantyhose. It was found that female consumers felt cold on the legs when wearing pantyhose which puts forward more requirements on pantyhose for its ability to keep warm. The thinner and more permeable the pantyhose,the thermal insulation was smaller. And the thicker the pantyhose,the pressure it caused to the body was higher. Sample 1# brought the highest prickle sensation, and prickle sensation was increased with the movement of the body. Samples 2# and 3# caused the highest and lowest thermal sensation,which was in line with their thermal insulation.

关键词： comfort sensation insulation Comfort preference questionnaire Winter permeable clothing interview

APPLICATION OF FINITE ELEMENT METHOD TO COMPARING THE NIR STENT WITH THE MULTI-LINK STENT FOR NARROWINGS IN CORONARY ARTERIES

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Acta Mechanica Solida Sinica 2015年第5期28卷 605-612页

作者： S.Misagh Imani A.M.Goudarzi P.Valipour M.Barzegar J.Mahdinejad Seiyed E.Ghasemi department of Mechanical engineering Babol University of Technology department of Textile and apparel Qaemshahr Branch Islamic Azad University Young Researchers and Elite Club Qaemshahr Branch Islamic Azad University

‘Stent versus stent＇ studies are a kind of randomized trials which are designed to show the superiority of the new stent designs compared with the previously approved ones. These studies are usually used by regulatory agencies, such as the U.S. Food and Drug Administration （FDA）, to give an approval to new stent designs. The problem with these clinical trials is their high cost and difficulty. In this paper, a numerical alternative for ＇stent versus stent＇ complicated clinical studies is presented. A finite element model is developed to investigate the influence of stent design on the outcome after coronary stent placement. Two commercially available stents （the NIR and Multi-Link stents） are modeled and their behavior during the deployment is compared in terms of stress distribution, radial gain, outer diameter changes and foreshortening. Moreover, the effect of stent design on the restenosis rate is investigated by comparing the stress distribution within the arteries. An analysis of the arterial wall stresses in the stented arteries indicates that the Multi-Link stent design causes lower stress to an atherosclerotic vessel with a localized stenotic lesion compared to the slotted tube NIR design. The findings correlate with the observed clinical restenosis rates, which have reported higher restenosis rates in the NIR compared with the Multi- Link stent design.

关键词： stent vs. stent studies finite element method coronary stent plaque vessel