检索结果-南通市图书馆

New separation algorithm for touching grain kernels based on contour segments and ellipse fitting

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第1期12卷 54-61页

作者： Lei YAN Cheol-Woo PARK Sang-Ryong lee choon-young lee School of Mechanical Engineering Kyungpook National University Daegu 702-701 Korea School of Technology Beijing Forestry University Beijing 100083 China

A new separation algorithm based on contour segments and ellipse fitting is proposed to separate the ellipse-like touching grain kernels in digital *** image is filtered and converted into a binary image *** the contour of touching grain kernels is extracted and divided into contour segments (CS) with the concave points on *** next step is to merge the contour segments,which is the main contribution of this *** distance measurement (DM) and deviation error measurement (DEM) are proposed to test whether the contour segments pertain to the same kernel or *** they pass the measurement and judgment,they are merged as a new *** with these newly merged contour segments,the ellipses are fitted as the representative ellipses for touching *** verify the proposed algorithm,six different kinds of Korean grains were *** results showed that the proposed method is efficient and accurate for the separation of the touching grain kernels.

关键词： Separation algorithm Touching grains Contour segments Ellipse fitting

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

从微观经济学看企业计算市场发展

程序员 2014年第7期 107-111页

作者：蒋清野 young choon lee Albert Y. Zomaya 悉尼大学信息技术学院

基于2006—2013年的历史市场数据，本文从微观经济学的角度分析了企业计算资源市场的供需关系。工业界可以依据本文所提供的数据设计更好的定价策略，从而同时达到市场扩张和增加营收的目的。

关键词：微观经济学市场发展企业计算供需关系资源市场角度分析定价策略数据设计

Characteristics analysis and library development for piezoelectric transformer to drive a ballast for a 35 W class fluorescent lamp using PSPICE modeling

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Central South University 2016年第1期23卷 169-180页

作者： KIM young-choon Division of Mechanical and Automotive Engineering College of Engineering Kongju National University

PSPICE model driven by an electric equivalent circuit of a piezoelectric circuit is presented. In order to confirm this model to be effective, an independent model of cold cathode fluorescent lamp(CCFL) driving circuit is used to conduct simulations, leading to a precise modeling. A library is configured through modeling and its accuracy is verified through simulations for widely used and representative lamps such as CCFL, fluorescent lamps, HID lamps, and electrodeless fluorescent lamps. On the basis of experiments, a lamp simulation is also performed using PSPICE, which allows us to take advantage of the lamp library easily. Also, PSPICE model driven by an electric equivalent circuit of a piezoelectric transformer is presented. In order to confirm this model to be effective, an independent model of CCFL driving circuit is used to conduct simulations, leading to a precise modeling. In addition, a new type of electronic ballast is proposed, which allows 35 W-class(T5-class) fluorescent lamp to work. This system is built by a rectifier which has improved power factor and half-bridge series resonant inverter. Also, with size of 27.5 mm high, 27.5 mm wide and 2.5 mm thick, the produced piezoelectric transformer has a high step-up ratio, through which it is possible for the electric ballast circuit to be lighter, smaller and more efficient. After the produced ballast is used to drive the fluorescent lamp for 25 min, it yields 0.95 in power factor correction, 86% in efficiency, 35.07 W in output voltage and 20.5 °C in temperature increase while meeting the characteristics of the 35 W-class fluorescent lamp.

关键词： PSPICE 35 W-class cold cathode fluorescent lamp (CCFL) fluorescent lamp library

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

在线全文

学校读者我要写书评

暂无评论

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

NC code generation for laser assisted turn-mill of various type of clovers and square section members

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2012年第11期19卷 3064-3068页

作者： CHOI Jun-young lee choon-man Department of Mechanical Design & Manufacturing Engineering Changwon National UniversityChangwon 641-773Korea

Laser assisted turning （LAT） is one of the advanced machining technologies, which uses laser power to heat the surface of a workpiece before the material is removed. It has several advantages of low manufacturing costs, high productivity and high qualities to machine difficult-to-cut materials such as silicon nitride, muUite, zirconia and Ni. A large part of studies on LAT have been focused on a round bar. With increasing demands for high quality products and high performance engineering system, the researches on LAT for clover and square section members are necessary. But, these workpieces are impossible to be machined on conventional CNC lathe and to generate NC code with current CAM softwares. As a basic research for combining LAT with a tilting index table type 5-axis machining center, i.e. laser assisted turn-mill, a new method is suggested to generate NC code that can process various types of clover and square section members through development of C＋＋ program.

关键词： laser assisted turning (LAT) NC code clover section turn-mill square section turn-mill

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

在线全文

学校读者我要写书评

暂无评论

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

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

在线全文

学校读者我要写书评

暂无评论

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

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

在线全文

学校读者我要写书评

暂无评论

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