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Contrast evaluation methods for natural color images in display systems: within- and cross-content evaluations

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第11期12卷 897-909页

作者： choon-woo kim School of Information and Communication Engineering Inha University

Contrast evaluation can be used as a criterion to evaluate performance of contrast enhancement algorithms and to compare contrast capability of display systems. This paper deals with contrast evaluation models for natural color images. Two separate models are defined for within- and cross-content evaluations. The former is to differentiate the perceived contrast of the images with the same content. The latter is to discriminate the differences in contrast among the images with different contents. Perception mechanisms are quite different for within- and cross-content evaluations. Local contrast plays an important role in within-content evaluation. In contrast, global contrast dominates the contrast perception for cross-content evaluation. Results of human visual experiments show that the proposed evaluation models outperform previous methods for both within- and cross-content evaluations.

关键词： Contrast evaluation Global contrast Local contrast Within content Cross content Statistical significance

Enhancement of Performance by Blade Optimization in Two-Stage Ring Blower

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Journal of Thermal Science 2010年第5期19卷 383-389页

作者： choon-Man Jang Gi-young Han Plant Research Division Korea Institute of Construction Technology dh-m co. ltd.626-5Bulmo-dongSeo-guIncheon404-270Korea

This paper describes the shape optimization of an impeller used for two-stage high pressure ring *** shape variables,which are used to define an impeller shape,are introduced to increase the blower *** pressure of a blower is selected as an object function,and the blade optimization is performed by a response surface ***-dimensional Navier-Stokes equations are introduced to analyze the internal flow of the blower and to find the value of object function for the training *** good agreement between experimental measurements and numerical simulation is obtained in the present *** the shape optimization,it is found that a hub height is effective to increase pressure in the ring *** pressure rise for the optimal two-stage ring blower is successfully increased up to 1.86% compared with that of reference at the design flow *** recirculation flow having low velocity is formed in both sides of the impeller outlet by different flow direction of the inlet and outlet of the *** flow field inside the ring blower is also analyzed and discussed.

关键词： Ring blower Blower performance Numerical simulation Blade optimization Response surface method

DC Motor Speed Regulator via Active Damping Injection and Angular Acceleration Estimation Techniques

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IEEE/CAA Journal of Automatica Sinica 2021年第3期8卷 641-647页

作者： Seok-Kyoon kim choon Ki Ahn Department of Creative Convergence Engineering Hanbat National UniversityDaejeon 341-58Republic of Korea School of Electrical Engineering Korea UniversitySeoul 136-701Republic of Korea

This paper suggests a novel model-based nonlinear DC motor speed regulator without the use of a current *** current dynamics,machine parameters and mismatched load variations are *** proposed controller is designed to include an active damping term that regulates the motor speed in accordance with the first-order low-pass filter dynamics through the pole-zero ***,the angular acceleration and its reference are obtained from simple first-order estimators using only the speed *** effectiveness is experimentally verified using hardware comprising the QUBEServo2,myRIO-1900,and LabVIEW.

关键词： Active damping injection angular acceleration estimator DC motor(DCM) speed regulation

Isolation and characterization of Pseudomonas otitidis WL-13 and its capacity to decolorize triphenylmethane dyes

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Journal of Environmental Sciences 2009年第7期21卷 960-964页

作者： WU Jing JUNG Byung-Gil kim Kyoung-Sook LEE young-choon SUNG Nak-Chang Department of Biotechnology Dong-A University Busan 604-714 South Korea Brain Korea 21 Center for Silver-Bio Industrialization Dong-A University Busan 604-714 South Korea Department of Environmental Engineering College of Engineering Dong-A University. Busan 604-714 South Korea

Pseudomonas otitidis WL-13, which has a high capacity to decolorize triphenylmethane dyes, was isolated from activated sludge obtained from a wastewater treatment plant of a dyeing industry. This strain exhibited a remarkable color-removal capability when tested against several triphenylmethane dyes under both shaking and static conditions at high concentrations of dyes. More than 95% of Malachite Green and Brilliant Green was removed within 12 h at 500 μmol/L dye concentration under shaking conditions. Crystal Violet lost about 13% of its color under the same conditions tested. The rate of decolorization increased when the M9 medium was supplemented with yeast extract. The optimum pH and temperature for color removal were 7-9 and 35-40℃, respectively. The observed changes in the visible spectra and the inspection of bacterial growth indicated the color-removal by the adsorption of dye to the cells during incubation with strains.

关键词： adsorption decolorization Pseudomonas otitidis WL-13 triphenylmethane dye

Applications of numerical optimization techniques to design of axial compressor blades

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航空动力学报 2007年第4期22卷 645-652页

作者： choon-Man Jang Kwang-Yong kim Fire and Engineering Services Research Department KICT Department of Mechanical Engineering Inha University

This paper describes the shape optimization of NASA rotor 37 and rotor and stator blades in a single-stage transonic axial *** optimization of the blades operating at the design flow condition has been performed using the response surface method and three-dimensional Navier-Stokes ***-layer approximation is introduced to the Navier-Stokes equations,and an explicit Runge-Kutta scheme is used to solve the governing *** three design variables,blade sweep,lean and skew,are introduced to optimize the three-dimensional stacking line of the *** objective function of the shape optimization is an adiabatic *** the optimization of rotor and stator blades, optimal blade shape can be *** is noted the increase of adiabatic efficiency by optimization of the blade shape with the stacking line in the single-stage transonic axial compressor is more effective in a rotor blade rather than a stator blade because of the large deformation of blade shape in the stator blade.

关键词：轴挤压叶片机航空推进系统最优化倾斜

Neuroprotective effect of the ethanol extract of Artemisia capillaris on transient forebrain ischemia in mice via nicotinic cholinergic receptor

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Chinese Journal of Natural Medicines 2018年第6期16卷 428-435页

作者： Huiyoung Kwon Ji Wook Jung young choon Lee Jong Hoon Ryu Dong Hyun kim Department of Medicinal Biotechnology College of Health SciencesDong-A UniversityBusan 49315Republic of Korea Department of Herbal Medicinal Pharmacology College of Herbal Bio-industryDaegu Haany UniversityKyungsan 38610Republic of Korea Institute of Convergence Bio-Health Dong-A UniversityBusan 49315Republic of Korea Department of Life and Nanopharmaeeutical Sciences Kyung Hee UniversityKyung Hee UniversitySeou102447Republic of Korea Department of Oriental Pharmaceutical Science College of PharmacyKyung Hee UniversityKyung Hee UniversitySeoul 02447Republic of Korea Kyung Hee East-West Pharmaceutical Research Institute Kyung Hee UniversityKyung Hee UniversitySeoul 02447Republic of Korea

Artemisia capillaris Thunberg is a medicinal plant used as a traditional medicine in many cultures. It is an effective remedy for liver problems including hepatitis. Recent pharmacological reports have indicated that Artemisia species can exert various neurological effects. Previously, we reported a memory-enhancing effect of Artemisia species. However, the mechanisms underlying the neuroprotective effect of A. capillaris(AC) are still unknown. In the present study, we investigated the effect of an ethanol extract of AC on ischemic brain injury in a mouse model of transient forebrain ischemia. The mice were treated with AC for seven days, beginning one day before induction of transient forebrain ischemia. Behavioral deficits were investigated using the Y-maze. Nissl and Fluoro-jade B staining were used to indicate the site of injury. To determine the underlying mechanisms for the drug, we measured acetylcholinesterase activity. AC(200 mg·kg-1) treatment reduced transient forebrain ischemia-induced neuronal cell death in the hippocampal CA1 region. The AC-treated group also showed significant amelioration in the spontaneous alternation of the Y-maze test performance, compared to that in the untreated transient forebrain ischemia group. Moreover, AC treatment showed a concentration-dependent inhibitory effect on acetylcholinesterase activity in vitro. Finally, the effect of AC on forebrain ischemia was blocked by mecamylamine, a nonselective nicotinic acetylcholine receptor antagonist. Our results suggested that in a model of forebrain ischemia, AC protected against neuronal death through the activation of nicotinic acetylcholine receptors.

关键词： Artemisia capillaris Transient forebrain ischemia Acetylcholinesterase Nicotinic acetylcholine receptor

Development of a one-axis manipulator for laser-assisted machining

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Journal of Central South University 2013年第2期20卷 378-384页

作者： kim Dong-hyeon LEE choon-man Department of Mechanical Design & Manufacturing Engineering Changwon National University

Laser-assisted machining has been considered as a new alternative machining method of difficult-to-cut materials. A laser module with one-axis manipulator is developed to focus on preheating laser beam effectively. First of all, the thermal characteristic analysis was performed to verify the importance of laser module location. Laser module should be moved within 1 mm. Analysis conditions of three positions in driving range of the one-axis manipulator are selected. And a C coupling is used as a connection device for spindle and laser module. An initial model has one C coupling, and the number of C coupling has been increased from 1 to 2 in an improved model. And the analysis is carried out again for the one-axis manipulator. The results of the static analysis, the maximum displacement and the maximum stress are decreased by 22% and 11%, respectively, for the improved model when the laser module is located at farthest away from the spindle unit. As a result of the modal analysis, the first natural frequency mode is increased by 13%, 18% and 12% at these positions of the improved model, respectively. The harmonic analysis of the improved model was performed by analyzing the results of the modal analysis. The maximum deformation was 0.33 mm in driving unit at 222 Hz. And the maximum compliance of the ISO axis direction was 0.23 mm/N. Finally, the one-axis manipulator has been fabricated successfully using the analysis result.

关键词： finite element analysis (FEA) laser-assisted machining manipulator

Development of two-axis control index table driven by direct drive motors

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Journal of Central South University 2011年第6期18卷 1962-1968页

作者： kim Jae-hyun LEE choon-man School of Mechatronics Changwon National University

The stability and reliability of a tilting index table should be considered at the design stage. A design method for the lightweight and improvement of the stability of the structure in a tilting index table was proposed using a commercial analysis program, ANSYS Workbench 12, by analyzing the static-thermal characteristics of the developed high-accuracy tilting index table at its design stage. The results of the performed structural analysis show that the maximum stress is generated at the stock tail part. An optimum design for the stock tail part was carried out to reduce the maximum stress and deformation. Also, the design variables were determined by considering the support of the stock tail part for the C-axis body. In the comparison of the results before and after the optimization, the maximum deformation and stress are improved by 2.8% and 8%, respectively.

关键词： tilting index table structural analysis modal analysis thermal analysis optimum design

Multi-stage optimum design of magazine type automatic tool changer arm

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Journal of Central South University 2012年第1期19卷 174-178页

作者： kim Jae-Hyun LEE choon-Man School of Mechatronics Changwon National UniversityChangwon 641-773Korea

To enhance machining efficiency,tool change time has to be ***,for an automatic tool changer attached to a machining center,the tool change time is to be *** the automatic tool changer is a main part of the machining center as a driving *** static attributes of the automatic tool changer using the commercial code,ANSYS Workbench V12,were tried to *** the optimum design of automatic tool changer arm was proposed by performing the multi-stage optimum *** shape optimization of the automatic tool changer was proposed and the result was verified to obtain acceptable *** is possible to obtain an optimized model in which the maximum deformation,maximum stress,and mass are reduced by 10.46%,12.89% and 9.26%,respectively,compared with those of the initial ***,the results between conventional method by the design of experiments and proposed method by the multi-stage optimum design method were compared.

关键词： automatic tool changer optimum design structural analysis exchange arm