유압관로의 임피던스 전달특성

유영태,나기대,모양우,김지환 朝鮮大學校 機械技術硏究所 2003 機械技術硏究 Vol.6 No.2

Design for quite operation of fluid power system requires t h understanding of noise and vibration characteristics of t h system This paper presents a dynamic response of design of hydraulic circuit. Experimental investigations on the attenuation characteristics of pressure ripple in automotive power steering hydraulic pipe with dynamic response of hydraulic pipe line is examined.

수준별 영어과 수업에서의 학습지 모형에 관한 연구

곽동기,김영경 부산여자대학교 교육과학연구소 1998 교육과학연구 Vol.- No.3

高效率 MOS(Al-SiO_2-pSi) 太陽電池의 設計와 製作

李英姬,張志根,李炯坤 단국대학교 1985 論文集 Vol.19 No.-

The mm insulating layer of MOS solar cell allows control over not only the magnitude of the dark current flowing through the diode but also the dominant type (majority or minority carrier) of this current. Desirably low values of dark current for majority carrier have been postulated incorporating charge trapping centers suitably located within insulator or high fixed positive charge density (Q_ss) at the Si-SiO_2 interface. Based on these models, the MOS solar cell with surfaceinversion layer by incoporation high Q_ss at the Si-SiO_2 inferface is designed in this paper. As a result of fabrication of this cell using pSi Substrate (orientation;〈111>, ρ; 10Ω-㎝), the average efficiency of the MOS solar cell is obtained with 10% on the active area basis.

유압관로에서 비정상 압력측압공의 동특성에 관한 연구

나기대,유영태,김지환 조선대학교 에너지.자원신기술연구소 2000 에너지·자원신기술연구소 논문지 Vol.22 No.2

In this study, the analysis of the dynamics characteristics and performance investigation of the pressure measurement in the hydraulic pipe. The exact solution of the frequency response is obtained by using the complicated transfer function. The discrepancy with the exact and the approximate is small, so the approximation solution is adopted to compare the experimental result with the theoretical analysis. The pressure measurement in the hydraulic pipe is caused by length of capillary and according to the end volume size. The experimental and calculate result show that characteristic of the pressure .measurement in the hydraulic pipe varies with the length of capillary and volume size. Therefore present theoretical formulation and experimental result can be used generally in designing and performance evaluation of all the hydraulic pressure measurement in the hydraulic pipe

전(煎)의 문헌적 연구(Ⅱ) : 해산물을 이용한 전

마영순,이효지 漢陽大學校 韓國生活科學硏究所 1999 韓國 生活 科學 硏究 Vol.- No.17

The purpose of this study is to review the kinds, cooking practices, materials and recipes of Jeon by surveying 39 references, which published during the period from 1670 to 1995. The primary materials used for Jeons are fish and shellfish. In order to prepare the Jeon, the materials shall be chopped or pounded first, and then salt or pepper powder shall be sprayed over the material shall be clad with flour or egg to be fried on the pan. The number of Jeons found through this study is 38 in all. This recipe has continued to be used since long ago. All in all, the recipe for Jeon lies in proper preparation of material, powdering, egg-cladding, control of frying temperature, amount of frying oil, on-pan handling, timing between cooking sequences and timely turnover etc. In generally, Jeon may well be taken after having been stained by the soybeen-sauce added with vinegar and pine-nut powder.

경계조건변화에 따른 동력전달관로의 동특성

나기대,유영태,김지환 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.6

Design for a quiet operation of fluid power system requires the understanding of noise and vibration characteristics of the system. It's not easy to analyze noise problem in hydraulic cylinder used in typical actuator Because they've got complex fluid dynamics. One of the fundamental problems associated with the hydraulic system is the pulsating flow in pipe lines, which can e tackled by the analysis under simplifying assumptions. The present study focuses on theoretic analysis and experimental study on the dynamics of laminar pulsating flow in a circular pipe. We analyze the propagation characteristics of the pressure pulse within a hydraulic pipe line taking into account the pulsating flow frequency variation. We also measure instantaneous pressure pulses within pipe line to identify the transfer functions. We conduct series of experiments to investigate the propagation characteristics of pressure pulse for various pressure of pulsating flow. The working fluid of the present study is ISO VG46 and the temperature ranges from 20 to 60℃ with normal pressure at 4000kPa. The flow rate is measured by using an ultrasonic flow meter. Pressures at fixed upstream and downstream positions are measured concurrently. The electric signals of the pressure sensor are stored and analyzed using a system analyzer(PKE 983 series). The frequency is varied in the range of 10~500Hz. The Reynolds number is kept below 2,000. In the present study, boundary condition was varied by installing a surge tank and an orifice at the end of pipe. Experimental and theoretical results were compared each other under various boundary conditions.

Heat Transfer Characteristics of a Miniature Two-Phase Closed Annular Thermosyphon

천원기,이영수 濟州大學校 産業技術硏究所 1995 산업기술연구소논문집 Vol.6 No.-

An experimental study on the heat transfer performance of a miniature two-phase closed thermosyphon is described. Water, ethanol and methanol have been tested as the working fluids. A visualization regarding the motion of liquid with boiling, scattering of liquid drops and condensation of vapor has been made to clarify the heat transfer mechanism in the miniature thermosyphon. Out of many possible controlling variables, the effects of (a) the insert thickness (b) the ratio of heated-length to cooled-length and (c) the heat flux, were investigated.

濕熱調理法에 의한 饌物類의 分析的 考察

李英子,李孝枝 漢陽大學校 韓國生活科學硏究所 1987 韓國 生活 科學 硏究 Vol.- No.5

I have studied the Kinds of side dishes and the changes of food by moist cooking method of Korean side dishes according as ages which included many Korean cook books written from 1670 to 1943. The results of study and analysis are as following. 1) There were Jim, Tang, Jockpyun, Sun, Jungol, Cho, Jochi, Jorim, Gigimi, Pyunyuk, Suran and Sundai cooked by moist cooking method. 2) Four Kinds of Sundai and five Kinds of Jockpyun were the food since 1670. Ten Kinds of Pyunyuk were the food since seventeen century. Seventeen Kinds of Jungol were the food since the early of eighteen century. Twenty-three Kinds of Jorim were the food since the niddle of eighteen Century. Two Kinds of Suran were the food since the late of eighteen century. 3) Used materials for Jungol, Jorim, Pyunyuk, Cho, Sundai, Suran and Jockpyum were meat, poultry, fish and shell fish, vegetables, mushrooms, dried fish, egg, bean curds, wheat flour, rice powder, starch and fruits. Seasonings were pepper, sesame powder, soy bean sauce, green onion, garlic, sugar, sesame oil, ginger, salt, sliced red pepper, glutamic sodium, honey, cinnamon, red pepper powder, red pepper paste, vinegar, mustard, clove, ginger powder and so on.

紅花의 造血作用에 對한 實驗的 硏究

徐榮培,李龍求,李永喆,閔平基 대한본초학회 2002 大韓本草學會誌 Vol.17 No.1

In order to investigate the haematopoietic effects of Carthami Flos on various experiments were studied. The results were obtained as follows: 1. In the proliferous effect of bone marrow cells, water extracts of Carthami Flos played an important role on the proliferating bone marrow cells compared with control group at low density. 2. The water extracts of Carthami Flos promoted the proliferation of the bone marrow cells into cluster, BFU-E, CFU-GEMM and colony. 3. In the bone marrow cells treated with CTX, the water extracts of Carthami Flos promoted the SCF, EPO, IL-4, IL-6 gene expression, but gene expression of its receptors, c-kit, EPO-R, TPO, c-mpl, EKLF, GATA-1 were not promoted significantly. According to the above results, water extracts of Cathami Flos promoted not only the differentiation

골프기능 수행과 몰입경험에 관한 연구

윤기운,조영권 한국스포츠리서치 2005 한국 스포츠 리서치 Vol.16 No.2

This study examined the flow experience and golf performance. 230 golfers completed the flow questionnaire. That is to assess flow experience in golf performance. Results of this study showed as follows ; The First, there were difference in flow experience of golfer as a function of ability level. participant period, and practice time. And, there was more flow experience of man golfer than that of woman golfer. Second, participant period of golfer have positive effect on flow experience. In Conclusions, Continuance period of golf participant is very important on flow experience in golf performance.