열싸이펀을 이용한 간접 열교환기에 관한 실험

이승홍,이승엽 釜山大學校生産技術硏究所 1997 生産技術硏究所論文集 Vol.53 No.-

2상 밀폐형 열싸이펀이 냉,온수 사이의 열전달 매개체가 되는 간접 열교환기에 관한 실험을 수행하였다. 에탄올, 물, 아세톤 중에서 열싸이펀의 작동 유체로 물을 사용했을 때 열싸이펀 및 열교환기의 열전달 성능이 최대가 되었다. 냉, 온수 Re수의 비 Re*(=??/??)의 값에 따라 열교환기가 우수한 열전달 성능을 낼 수 있는 범위를 조사했다. 열싸이펀의 작동 유체로 물을 사용한 경우, 본 연구의 실험 범위중 Re*가 0.5∼3.0정도일 때 열교환기의 전체 열저항이 최소가 되었으며 열전달 성능이 우수한 범위였다. An indirect type heat exchanger using a two phase-closed thermosyphon as a heat transfer device operating between hot and cold water has been experimentally investigated. The best working fluid of thermosyphon is water among ethanol, water, acetone. The range of the best heat transfer capability has been investigated depending on the ratio of heating and cooling fluids' Reynolds number, Re*(=??/??). For water, as a working fluid of thermosyphon, in the range of Re* between 0.5∼3.0, total thermal resistance of heat exchanger is found to be minimum and to show maximum heat transfer performance.

온라인 동조 PI 제어기법을 이용한 영구자석형 동기전동기의 속도제어기 설계

林相德,朴勝燁,全寅孝,崔重暻 창원대학교 공작기계기술연구센터 1999 연구업적집 Vol.1 No.1

본 논문은 브러시리스 직류 전동기의 속도제어를 위해 파라메타의 추정 없이 입력과 출력의 패턴을 관찰하여 PI 이득을 온라인(On-line)으로 설정하는 방법을 제안한다. 비례이득은 한계입력을 인가하여 가장 빠른 속도 상승을 유도하는 과정에서 설정되고, 적분이득은 비례제어 과정 중에 오버슈트 방지와 안정된 수렴이 적적히 이루어지도록 설정된다. 따라서 제안된 PI이득 조정은 온라인으로 제어와 동시에 수행됨으로써 시스템 파라메타 추정 등의 부가적인 작업이 필요 없다. 본 논문에서 제안하는 PI이득 조절기법은 직류전동기의 속도제어에 있어서 빠른 응답과 오버슈트 문제를 동시에 해결할 수 있고, 기존의 Auto-tuning 방법보다 간편하고 실용적이다. 컴퓨터 시뮬레이션과 실제 실험을 통하여 제안하는 방법의 유용성과 안정성을 보인다. In this paper, a method of on-line PI gain-tuning is proposed for the speed control of brushless D.C. motor by investigating the pattern of input and output without estimating parameter. Proportional gain is tuned in the process to obtain a fast speed response by supplying the maximum constant input And integral gain is appropriately tuned in the process of proportional control so that the response may be stably converged and the overshoot may be prevented. Therefore because both control and gain-tuning are executed concurrently, additional works that estimate parameters and so on aren't required in the proposed method. In the proposed method, both fast-response and overshoot problem are well solved, and it is mire useful and convenient than existing auto-tuning methods in the speed control of D.C motor. It is illustrated by simulations and experimental results that the proposed method is useful and stable.

견부통 환자의 임상적 고찰

김상엽 광주보건대학 1995 論文集 Vol.20 No.-

The subjects of this study were 104persons who received physical treatment for shoulder pain of Dong Jin Clinic Center during the period Januray 1, 1995 to April 30, 1995. Analysis of patient's general characteristics were carried out. The subjects were 38(36.5%) males and 66(63.5%) females. their average was 46.7 years with the largest group of 40-59 years (31persons or 29.8%). The majority of patients came for physical treatment in 3months after onset of shoulder pain(66persons or 63.5%). The patients who have complained shoulder pain and limitation of motion were 52(50.0%)persons, posterior neck pain and limitation of motion were 45(43.3%)persons. The patients diagnosed as frozed shoulder were 48(46.2%)persons, sprain were 26(25.0%)persons. As for the average duration of the physical treatment was 9.7days with the largest group within 5days (42persons or 40.4%).

Pentoxifylline과 고압산소요법이 백서 무축 피판 생존율에 미치는 영향

김사엽,이상한 慶北大學校 齒科大學 1991 慶北齒大論文集 Vol.8 No.2

The effects of pentoxifylline, hyperbaric oxygen and combination of the two on the survival rate of random pattern skin flaps were evaluated in an experimental study in rats. Thirty-five rate were divided into five groups. Cephalic based random pattern flaps were designed on the back of the rats and control group animals received twice-daily an intraperitoneal injection of 1cc normal saline solution for seven days before surgery and every 12 hours after the operation for seven days and to control for the stress of injection. Group I rats were treated with pentoxifylline received 20 ㎎/kg intraperitoneally at 24, 12, and 1 hour(s) before flap elevation and every 12 hours after the operation for seven days. Group Ⅱ rats were treated with twicedaily pentoxifylline injections for seven days before surgery and were then managed as Group I. Group Ⅲ rats were treated with hyperbaric oxygen within four hours after flap operation. Group Ⅳ rats were given exactly as Group Ⅱ and Group Ⅲ. The survival rate to the total flap was calculated. The results were as follows: 1. The mean survival rate of the flaps was 54.60±16.78% in control, 61.34±10.62% in group I, 64.96±3.08% in group Ⅱ, 71.93±9.26% in group Ⅲ, 86.67±8.17% in group Ⅳ. 2. The survival rate of the flaps were increased in group Ⅰ,Ⅱ, Ⅲ, Ⅳ when compared with the control group. 3. The combination of pentoxifylline and hyperbaric oxygen showed synergistic effect on the survival rate of the flap. 4. In the histopathologic study at postoperative 7th day, abundant proliferation of fibroblast and capillary blood vessels were observed in the experimental Ⅲ group, while severe infiltration of inflammatory cells were observed in the control group.

Bleomycin 투여가 mice신장에 미치는 독성에 관한 생리학적, 생화학적 및 초미세형태학적 연구

김상엽,조성태 광주보건대학 1991 論文集 Vol.16 No.-

Bleomycin, a glycopeptide antibiotic isolated from Streptomyces Verticillus, ha been used as an anticancer drug active aganist human squamous cell carcinoma of skin and lung. In this experiment, the author pursed the effect of bleomycin on the mouse kidney, observing the physiological, biochemical and ultrastructural changes in glomerulus and convoluted tubules. Mice(ICR strain) were used as experiment animals which were divided into two groups, the control and experimental groups. In order to elucidate the nephrotoxicity of the mouse administrated bleomycin in D. W., this study was carried out. Bleomycin was injected 20 units per kg of body weight to abdominal portion of mouse in 1 week, 2 weeks, 3 weeks, and 4 weeks. After 5 weeks, the left kindey was taken out from the mouse with injicted bleomycin and investigatigated the damages of the cells by the ultrastructural inspections. The results obtained were as follows 1. The thickened basement mimbrane of glomerulus and closed urinary space, fused parietal epithelial cells were observed, respectively. 2. Destructed brush border, granular degeneration, formed crescent, fused foot process, vacuolation of proximal and distal convoluted tubules were shown. 3. Phsiological characteristics of experimental groups, thrombocyte, Hematocrit and MCV were significantly increased. 4. Total lipid concentration, blood urea nitrogen were slightly increased and total cholesterol and albumins were significantly increased on all experimental groups. 5. In the structural changes of the mitochondria in kidney treated with bleomycin the organelles changes into a spherical or oval shapes, irregular cristae and destructed mitochondria were shown. From the above results, bleomycin damages both proximal and distal convoluted tubular epithelial cells and glomerulus in mice kidney.

DNA의 분리 및 제한효소에 관한 연구

김상엽,박민희 광주보건대학 1993 論文集 Vol.18 No.-

The pBN18 of the gene fusion vector was double digestion with HindⅢ and EcoRⅠ for the analysis of the restriction enzyme sites. As a results, the fragments of 1.2Kb and 4.6Kb were made. Therefore it was conformed that pBN18 includes the sites of HindⅢ and EcoRⅠ. The pBN18 contained the ClaⅠ site to digestion with ClaⅠ restriction enzyme. A study was conformed the restriction enzyme sites of pBN18, pBN18A and pBN18B and DNA sizes of pBN18 and pBN18B were compared with the agarose gel of the electrophoresis.

E.coli의 pBN18 플라스미드 DNA의 구조 및 발현의 전자현미경 관찰

김상엽 광주보건대학 1994 論文集 Vol.19 No.-

This study was visualized the transcriptional activity, the size and the modelof plasmid DNA by electron microscopy. Plasmid pBN18, pBN18A and pBR322 were visualized by way of electron microscopy. Mica-press adsorption method that alows selective visualization of the plasmid DNA released in situ from the bacterial cell is rapid and useful for visualization of plasmids. The released plasmid DNA was adsorbed preferential on mica in a divalent cation-free solution, and the Miller chromatin-spreading method may allow the physical interaction and transcription to be visualized. Therefore mica-press adsorption method and Miller chromatin-spreading method used to visualize the plasmid DNA, chromosomal DNA and gene expression. As a result, their estimated sizes of plasmid pBN18, pBN18A, pBN18B and pBR322 were 1.87 0.28(5.6 Kb)?, 1.53 0.12(4.6Kb)?, and 1.50 0.03(4.50Kb)?, respectively, and transcriptional activity was observed by the visualization of gene expression of chromosomal DNA.

헤게모니에 의한 유행전파 이론의 통합

이승엽 기전여자대학 1999 論文集 Vol.19 No.-

We have heard many things about fashion theory, and we know that there exist too different viewpoints and conclusions among them. But, I think they imply main points from the viewpoint of macro. If we take out something general among them, we can approach the truth of fashion theory. For that purpose we will cite the concept of Gramci's hegemony, and through the hegemony concept we can gain an insight into fashion theory.

不純物에 依한 Barium Titanates의 電氣的 性質

박창엽,박상만,김현재,양재면 연세대학교 산업기술연구소 1975 논문집 Vol.6 No.1

Semiconductive Barium Titanates was prepared and its electrical properties were investigated. For the purpose of controlling in valency Al₂O₃, SiO₂, TiO₂ and Sb₂O₃were doped in Barium Titanates as additions. 0.1∼0.2mole% Sb₂O₃ was effective in reducing resistivity of the order of 10³ohm-cm. Semiconductive Barium Titanates showed anomalous positive character in the temperature dependency of resistivity. It is proposed that conduction in those samples is caused by exchanging electrons between ?? ions and ?? ions.

웹서버를 이용한 그룹웨어 시스템의 설계 및 구현

김성연,최용엽 호서대학교 반도체제조장비국산화연구센터 2001 반도체장비학술심포지움 Vol.2001 No.-

이전까지의 결재방식은 직접 결재문서를 들고 결재자로부터 결재를 받는 방식이었으나 이제는 결재자가 집에서 또는 출장 중에 있어서도 웹 상에서 서버에 접속하여 결재자에게 전달되어진 결재문서를 검토, 결재할 수 있도록 하는 그룹웨어시스템이 필요하게 되었다. 본 연구개발의 주된 목적은 사내에서 기존의 결재방식을 웹 상에서 전자결재방식으로 변경하여 문서의 기안작성, 검토 결재 및 결재상황을 실시간으로 파악할 수 있도록 하였으며 또한, 이러한 모든 결재문서들은 데이터베이스에 최근문서, 일반문서, 정형화된 문서로 구분되어 저장되도록 하여서 권한이 부여된 사용자가 필요시 찾고자하는 문서를 실시간으로 검색 될 수 있도록 시스템을 구축하였다.