용접공들의 면역능에 관한 연구

이수일,조봉수,김영욱,고광욱,조원근,김영실,강수용,황인경,조병만,김돈균 大韓産業醫學會 1997 대한직업환경의학회지 Vol.9 No.1

The authors examined human immunity indicators such as CD4, CD8, Natural Killer(NK) cell, IgG, IgA, and IgM, and heavy metals such as Pb, Cr, Cd to evaluate the health hazard of welders. We selected total 126 male subjects, 60 welders who had more than 5 year working history as an exposure group, and 66 office workers and medical college students as a control group. This immunity evaluation approach is the first newly designed study that has never been tried in past studies on welder's heath evaluation. And the results were as follows. 1. Total lymphocyte count of peripheral blood was significantly higher in welder group, 2,615±650 ea/㎕ compared with 2,368±681 ea/㎕ in control group(p>0.05). 2. The proportion of CD4, CD8, NK cell in welder group was 37.5±9.4%, 24.0±8.8%, and 21.0±9.5%, respectively, and 35.5±6.5%, 25.0±6.9%, and 19.6±8.8% in control group. CD4 and NK cell were slightly higher, and CD8 was slightly lower in welder group. but there was no statistical significance between two groups(p≥0.05). 3. IgG, IgA, and IgM in welder group were 15.9㎎/㎗, 2.7㎎/㎗ and 1.5㎎/㎗, respectively, and 15.6㎎/㎗, 2.9㎎/㎗ and 1.7㎎/㎗ in control group. There was no statistical significance between two groups(p≥0.05). 4. Blood lead, cadmium and chromium concentrations were 4.2±1.8㎍/㎗, 0.4±0.38㎍/㎗, 1.2±0.6㎍/㎗ in welder group and 3.2±1.7㎍/㎗, 0.44±0.29㎍/㎗, 1.1±0.6㎍/㎗ in control group, respectively, and these value were within normal ranges.

내장재의 연소 및 독성가스 발생 특성 : 방염 카페트, 방염 후처리 합판, 쇼파 내자를 중심으로 The focus for resist-carpet, resist-treatment plywood, sofa leather

김일수,류경옥 韓國火災 ·消防學會 1998 한국화재소방학회논문지 Vol.12 No.2

화재위험성이 큰 유흥업소에서 주로 사용하는 내장재중 방염 카페트, 방염 후처리 합판, 쇼파 레자등 3가지 시료에 대한 연소특성과 CO, CO_2, O_2, NO_x, SO_2, HCN, HCI등 독성가스를 검출하여 화재 위험성을 비교평가 하였다. 연소특성에 있어 방염 카페트가 방염 후처리 합판, 쇼파 레자 보다 연소가 잘 되었고, 폭연 연소가 일어났다. 모든 시료에서 CO의 발생은 연소시작 후 1분 이내에 치사농도를 상회(上 It was studied a compared estimation of the fire risk of the three kinds of the interior materials, such as a resist carpet, a resist-after-treatment plywood and sofa leather. Toxic gases, CO, CO_2, NO_x, SO_2, HCN, HCI were detected during the combustion of the samples. A resist-carpet was more combustible than the resist-after-treatment plywood and sofa leather in the combustion characteristics and has a blow-up-combustion of combustion in all the samples. The generation of CO reached the lethal doses in minute after the combustion was begun. NO_x and So_2 were detected not more that each of the lethal doses, while HCN was detected in the carpet 20.6 times than the sofa leather, and 4.6 times than the resist-after-treatment plywood. HCI was detected in the carpet 4.48 times than the sofa leather and 2.47 times than the resist-after-treatment plywood. It is conclusion that the carpet was the highest in the fire risk among the three kinds of the interior materials.

Ramsay-Hunt Syndrome 환자 1례에 대한 증례보고

김일수,송인선,유호상,손원택,오민석,송태원 대전대학교 한방병원 2001 惠和醫學 Vol.10 No.1

Ramsey-Hunt Syndrome occurs when herpes zoster after the facial nerve. It causes vesicular eruption of the pinna, external auditory meaturs and ear drum, severe otalgia with associated facial paralysis and vertigo. We experienced a case of Ramsay Hunt syndrome and managed it with oriental medicine's teatment and therapy of western medicine

유한요소법을 이용한 용접부의 열전달 및 잔류응력 해석에 관한 연구

김일수,김인권,문채주,정영재,안영호 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.5

This paper represents to develop a computer software system which is capable to analyze the phase transformation of high strength steel(BV-AH32) and to predict heat transfer and welding residual stress due to phase transformation during Gas Metal Arc(GMA) welding. The developed model was considered temperature dependent properties such as young's modules, coefficient of thermal expansion and yield stress as well as the double ellipsoidal heat distribution by the moving arc. From the results, it was found that the longitudinal and transverse residual stresses calculated by the coupled analysis of heat transfer, residual stress and phase transformation showed good agreement with the experimental data. In addition, the temperature distribution as well as longitudinal and transverse residual stresses of weldment by the 1-pass and 2-pass of welding were also determined.

유리 측대퇴 피판을 이용한 압궤수부손상 재건술

김수신,백세민,김동일 大韓成形外科學會 1987 Archives of Plastic Surgery Vol.14 No.1

Utilizing the lateral thigh flap as originally described by Se-Min Baek. in 1983, we have treated seven cases of reconstruction involving crushing injuries of the hand. This flap is derived from the third perforator of the deep femoral artery and accompanying wein as per Baek`s method. When a large skin flap was needed such as the case of crushing hand injuries, a lateral thigh flap was more useful than any other flap. From our experiences for reconstruction of crushing hand injuries, the following advantages of this flap are noted: 1. It is possible to obtain a large size of all skin flap. 2. It is relatively thin with a small amount of the subcutaneous fat. 3. The vascular pedicle is long (10㎝ or more), facilitating microvascular anastomosis. 4. The lateral thigh flap can be a sensory flap. 5. It can be accommodated easily to any operating position.

공기압 실린더의 위치제어기 선정에 관한 연구

김일수,김기우,정영재,손준식,송창재,박주석 한국공작기계학회 1999 한국생산제조학회지 Vol.8 No.6

This paper concentrates on the position control of a pneumatic cylinder under parameter variation. A closed-loop control is proposed to design the different controllers(P, PI, PID, PD controller) in order to choose the best controller based on the fast and accurate control of the system. It is shown that the control algorithm is robust and effective in attaining the fast and accurate position control of system under time-dependent parameter variation. Experimental results showed that PD controller law is effective to obtain the fast response and to increase the stability of the system. The method is a useful control algorithm which always automatically adjusts the position control in accordance with the error, using carrier wave of triangle type regardless of changes on the operating condition and physical differences between components.

한국과 중국 중학 과학교과서 힘과 운동 단원 비교 분석

김규용,김일수 濟州大學校 師範大學 科學敎育硏究所 1999 科學敎育 Vol.16 No.-

This study is aimed to compare and analyze the systems or science education o Korea and China by the choice of the units "Force and Motion" in the Korean middle school textbook for the first grade and Chinese middle school textbook I. The results from the study are as follows; First, both countries have the same purposes of improving scientific technology and society. However, there is a remarkable difference that China should educate their children's ideology. Second, with regard to the unit, "Force and Motion". Korean unit has much more pages, graphics pictures, examples, and experiments, while Chinese unit has more pictures, photos experiments, questions for practice and reading materials. Therefore the contents of the Korean textbooks are much better structured, compared to Chinese textbooks. Finally, the units of "Force and Motion" by the theory of Romey were compared and analyzed. As a result, the contents and the evaluation of the chapter summaries have a tendency of authority. In contrast, the questions in the final section of the textbook and the activity index for inducement of students' exploration have remarkable tendency of exploration. In addition, with regard to the pictures and graphics, Korean textbooks have a tendency of exploration, while Chnese textbooks have a tendency of authority.

고강도 콘크리트를 사용한 철근콘크리트 보의 전단 거동에 관한 실험적 연구

김창희,고봉수,은희창,서일교 제주대학교 공과대학 첨단기술연구소 2001 尖端技術硏究所論文集 Vol.12 No.2

The shear capacity of reinforced concrete beam depends on the strength of concrete, the amount and strength of shear reinforcement bars, the support conditions of end points etc. These factors makes the shear behavior or capacity of reinforced concrete beam be complicated. For the purpose of grasping the shear behavior and capacity of reinforced concrete beams, sixteen specimens were tested. Most of specimens showed the shear failure along with the yielding of longitudinal bars or crushing of compressive concrete. The effects on each of test variables were related to the shear capacity of reinforced concrete beams. And, the comparison of the test results and ACI code showed the reasonable agreement.

GMA 용접의 윗면 비드폭 선정을 위한 최적 공정변수들

김일수,Prasad,전광석 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.4

This paper aims to develop an intelligent model for predicting top-bead width for the robotic GMA(Gas Metal Arc) welding process using BP(Back-propagation) neural network and multiple regression analysis. Firstly, based on experimental data, the basic factor affecting top-bead width are identified. Then, BP neural network model and multiple regression models of top-bead width are established. The modeling methods and procedure are explained. The developed models are then verified by data obtained from the additional experiment, and the predictive behaviors of the two kind of models are compared and analysed. Finally the modeling methods, predictive behaviors and the advantages of each models are discussed.

전자동 자반건조기 제작에 이용할 Water Jet의 유동해석 모델

김일수,박창언,정영재,손준식,남기우 한국공작기계학회 1998 한국생산제조학회지 Vol.7 No.5

This paper concentrates on the development of a computational design program to determine nozzle size in water jet, combing the numerical optimization technique with the flow analysis code. To achieve the above objective, a two-dimensional model was developed for investigating the fluid flow in water jet and calculating the velocity and pressure distributions. The mathematical formulation as a standard R-ε model was solved employing a general thermofluid-mechanics computer program. PHOENICS code, which is based on the Semi-Implicit Method Pressure Linked Equations (SIMPLE) algorithm. The developed code was applied to water jet design to determine the nozzle size, and investigated the effect of the change of nozzle location. Calculated results showed that the flow pattern is not changed as the change of nozzle location.