레이저와 2차원 배열의 광전검출기를 이용한 구조물의 변위측정 시스템의 개발에 관한 연구

강문필,이진이,김민수,김대정,최원하,강기훈,김종수,김훈 한국비파괴검사학회 2002 한국비파괴검사학회지 Vol.22 No.1

일반적으로 구조물은 외부의 정적 및 동적 하중과 외부환경으로 인하여 피로균열과 부식이 발생하며, 이것은 구조물의 변형을 유발하여 결국 파단으로 이어지기 때문에 균열과 부식의 검출 및 평가와 함께 구조물의 변형에 의한 진동, 변위 기울기와 같은 거동을 감시하는 것도 매우 중요하다. 이에 레이저 센서 시스템을 이용하여 이러한 거동을 측정하여 이상 유무를 모니터링할 수 있는 구조물 안전감시 시스템을 개발하였다. 본 시스템은 2차원으로 배열한 광전센서를 이용하여 구조물의 변형에 의해 유발된 광궤적의 변화를 감시하며 또한 데이터를 취득하고 신호처리 할 수 있는 운용 프로그램도 갖추고 있다. 본 연구에서는 개발한 안전 진단 시스템의 필드 적용에 앞서 실험실에서의 몇 가지 실험을 통하여 그 효용성을 검증하였다. A Safety Monitoring System using a laser and 2-D arrayed photo sensors is developed. To monitor of the deformation and small rotation of structure the developed optical system using 2-D photo sensor array was used to detect the variation of optical orbit of laser which was induced by deformation of the structure. Also, an operating program to manage the system and an algorithm for the data acquisition and the database are introduced. In this study, we demonstrated the capabilities of this system by laboratory experiments before applying the system to the field.

말기신부전 환자에서 혈액투석 전후의 QT간격분산 비교

강대웅,정지용,윤나라,안치용,김종오,신병철,정종훈,김현리 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.2

Background: Some cases of QT interval, corrected QT interval (QTc), QT dispersion (QTd) and corrected QT dispersion (QTcd) have been reported in ESRD, but these results are variable and the influence of a hemodialysis is still controversial, In this study, we investigated the effect of hemodialysis on QT and QTc interval and QT and QTc dispersion in patients with ESRD 15 min before and 15 minute after each hemodialysis. Methods: Sixty-seven patients with ESRD (men 33 & women 34) on three-times stable hemodialysis (>3 months) were randomly enrolled. Fifty control subjects with a similar age and normal renal function were enrolled from this hospital. Routine biochemical studies were measured pre- and post dialysis, at the time of the ECG. Plasma Na+, K+, BUN, creatinine, ionized calcium and phosphate were checked. Twelve-lead electrocardiographs were performed at 10㎜/mv and 50㎜/s using a HewIett-Packard Pagewriter 100, before and after a single hemodialysis session.The QT interval was measured from the onset of the QRS complex to the end of the T wave. If the end of the T wave was not clear in a particular lead then it was excluded from analysis. When U waves were present, the end of the T wave was taken as the nadir between the T and U waves. Each QT interval was corrected for heart rate using Bazett's formula (QTc==QT/√(RR)) (ms). The difference between maximal and minimal QT interval duration was defined as QT dispersion (QTd) in each of the 12 leads. Result: This study demonstrates that QT, QTd, QTcd is higher in hemodialysis patients compared with control subjects, and QT and QTd rise postdialysis to levels comparable to those seen acutely following myocardial infarction, when patients are at greatly increased risk of potentially fatal ventricular arrhythmias, Conclusions: QT interval and QT dispersion, markers of risk for arrhythmias and sudden death, are elevated in hemodialysis patients, and rise postdialysis. QT interval and QT dispersion is an easily obtainable, noninvasive, simple, inexpensive, and widely available method of risk stratification in uremic patients receiving chronic dialysis. Additional studies are needed to clarity whether increased postdialysis QT dispersion results in an increased occurrence of arrhythmias.

저가 후막 EL소자 제조 및 신뢰성 평가

강계원,김대연,이영훈,강봉석,박정현,최병호 금오공과대학교 산업기술개발연구원 2000 産業技術開發硏究 Vol.16 No.-

AC powder electroluminescence(EL) device consists of seven layers : PET substrate, transparent electrode, phosphor layer, dielectric layer, two layer metal electrodes and protective layer. Etch layer needs to control to improve electrical and optical properties. Both phosphor and dielectric layer among them is more important to increase its properties. For long-time reliability, proper choices of passivation and sealing material are essential. In this paper, influence of phosphor and dielectric layer thickness on EL performance is studied. Type of cellulos is selected as a sealing material to avoid moisture. To add two type of plasticizer to resin improves flexibility and passivation of EL devices. Through this experiments, technologies of fabrication low-cost thick film EL device can be established.

변압기 보호를 위한 Fuzzy Decision Making 알고리즘

강대훈,이승재,강상희,권태원 明知大學校 産業技術硏究所 1999 産業技術硏究所論文集 Vol.18 No.-

This paper presents a new fuzzy decision making algorithm for power transformer protection based on the Dempster-Shafer's theory of evidence. To distinguish internal faults from other transient states, four input variables are selected. Each time dependent fuzzy rule base is composed of twelve fuzzy if-then rules associated with their basic probability assignments (BPAs) for singleton - or compound-support hypotheses. Dempsters rule of combination is used to process the fuzzy rules and get the final decision. The proposed algorithm also has a capability to identify the inrush, over-excitation and external fault with current transformer (CT) saturation besides the internal fault.

혈액투석중인 말기신부전 환자에서 Fludrocortisone acetate (FCA) 투여 후 혈청 칼륨 저하 효과

류봉관,강대웅,정지용,윤나라,신병철,박경희,정종훈,김현리 朝鮮大學校 附設 醫學硏究所 2005 The Medical Journal of Chosun University Vol.30 No.1

Background: Hyperkalemia is a commonly encountered problem in dialysis patients with end-stage renal disease. In this study we evaluated the effect of mineralocorticoid therapy (fludrocortisono acetate) on serum potassium level in the serum of hyperkalemic end-stage renal disease patients. Methods: Fourteen patients on hemodialysis receiving fludrocortisone acetate (FCA) 0.1 mg/day were observed for 2 months periods. Consecutive monthly biochemical profiles were compared for the druration of the pre-and post-treatment of FCA. Result: Fourteen patients with mean age (±SE) of 51.5 years (4 males and 10 females) and mean hemodialysis period of 51.9 months were studied. Mean serum potassium levels significantly fell (p<0.05) during the post-FCA period (5.2±0.66 mEq/L) compared with potassium levels during the pre-FCA (5.8±0.43 mEq/L) period. Pre-and post-FCA values were not different for sodium, chloride, protein, albumin, AST/ALT, glucose, blood nitrogen, creatinine, phosphate and calcium. Conclusions: FCA appears to decrease serum potassium value in patients with end-stage renal disease. These results suggested that FCA could be effective to treat hyperkalemia without any adverse effect in patients undergoing hemodialysis.

화학과 생물 교과서에서 삼투 개념에 관한 설명 유형 분석

고영환,강대훈,박동조,김동욱,백성혜 한국과학교육학회 2002 한국과학교육학회지 Vol.22 No.4

이 연구에서는 고등학교와 대학교 화학과 생물 교과서에 제시된 삼투 개념에 대한 설명 유형 및 그림표현 유형을 분석하였다. 그리고 고등학교 화학Ⅱ 교과서와 생물Ⅱ교과서의 단원을 분석하였다. 분석 결과, 삼투현상에 대해서는 용매의 확산으로 설명하는 유형, 충돌로 설명하는 유형, 수화로 설명하는 유형, 농도의 평형으로 설명하는 유형 그리고 구멍을 막는 것으로 설명하는 유형 등 다섯 가지 유형으로 설명하고 있었다. 그리고 삼투 개념에 대한 설명 유형과 교과서에 제시된 그림 표현 유형 사이에 일치하지 않는 경우도 분석되었다. In this study, we analyzed types of explanation on osmosis concept that were represented in chemistry and biology textbooks of high school and college. There were 5 types of explanation on osmosis concept. The types of explanation were diffusion of solvent, collision, hydration, equilibrium of concentration and screen of holes. Last two types of explanation were classified into misconceptions. The various types of explanation on osmosis concept might cause to have be a reason that students had many misconceptions and to feel difficult to learn about osmosis concept. Many of textbooks is accord to types of concept explanation and figure explanation on osmosis but some is not

유지 투석중인 만성 신부전환자에서 허혈성 심질환의진단 지표로서의 심장트로닌-I의 유용성

신병철,강대웅,정지용,류봉관,서영욱,김정인,김범윤,김현리,정종훈 朝鮮大學校 附設 醫學硏究所 2004 The Medical Journal of Chosun University Vol.29 No.1

Background : Coronary disease is highly prevalent in patient with end stage renal disease (ESRD) and account for much of their observed morbidity and mortality. Troponin-I consistently maintains a high sensitivity and specificity and is most sensitive marker for ischemic heart disease (IHD). Method : We examed 49 hernodialyzed patients (22 male, 27 female) without evidence of acute coronary syndrome (ACS) for 6 months. Biochemical markers were measured in serial predialysis blood samples. For analysis, we used two cardio-specific assays for troponin-T (cTnT) as well as for troponin-I (cTnI) and compared the results with CK-MB (reference value ≤ 4.0 ng/mL) concentration. Results : Myocardial ischemia was observed in 47% (23/49) of patients. cTnT level above 0.1 ng/mL. and cTnI level above 0.5 ng/mL, were observed in 22% (11/49) and 20% (10/49) of patients respectively. cTnI revealed significantly higher positive rate in patients with myocardial ischemia than the patients without myocardial ischemia (43 % vs 30%) (p<0.05). cTnT and CK-MB revealed no difference in positive rate between the patients with and without myocardial ischemia (cTnT : 30% vs 15% and CK-MB : 30% vs 19%). The sensitivity and specificity of cTnI to myocardial ischemia were higher than those of cTnT and CK-MB (sensitivity 43% vs 30% and 30%. specificity 100% vs 85% and 81%). Conclusion: Both cTnT and cTnI are useful in ruling out myocardial injury in chronic renal failure patients. But. cTnI is a more sensitivity and excellent specificity of ischemic heart disease than cTnT and CK-MB in hemodialyzed patients. In patients with ischemic heart disease, the presences of DM and advanced age were higher than those in patients without ischemic heart disease (p<0.05). Among the baseline characteristics old age, elevated LDH and diabeties were significant more frequent in the patients with elevation of cardiac troponin-I (p>0.5 ng/mL) than those with cardiac troponin-I (p<0.5 ng/mL), p=0.038, p=0.049, and p=0.045, respectively. Our results suggest that these cTnI is the potential diagnostic marker for the prediction of IHD in ESRD patients.

에어로빅 웨이트트레이닝과 에어로빅 운동이 비만 여중생의 건강체력과 체조성에 미치는 영향

김기봉,김동훈,강대관 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.20 No.1

The purpose of this study was to analyze the effect of aerobic dance and aerobic weight training on health-related physical fitness and body composition in the in obese middle school girls who participated in regular and continuous exercise 12 weeks. 1. Differences and change of health-related physical fitness 1) Back muscle strength was significantly higher in Aerobic Dance Group than Aerobic Weight Training Group, and there were not significant differences in sit-ups, sit-and-reach and 800m run tine between two groups before training session, but there were not significant differences in all fitness factors between two groups after 12-week training. 2) In the changes of health-related fitness factors in each group before and after training, sit-and-reach and 8001n run time were significantly improved, but back muscle strength and sit-ups were not improved in Aerobic Dance Group, and back muscle strength, sit-ups and sit-and-reach were significantly improved, but 800111 run time was not improved in Aerobic. Weight Training Group. 2. Differences and Changes of Body Composition 1) There were not significant differences in all factors of body composition between two groups before and after training. 2) In the changes of body composition factors in each group before and after training, body weight, body fat and body mass index were significantly decreased, but %fat and lean body mass were not significantly changed in two groups.

Toluene, Xylene, Trichloroethylene 투여가 흰쥐의 시상하부와 뇌하수체의 GnRH, GnRH Receptor, Pit-1 유전자 발현에 미치는 영향

기노석,이종태,강대성,김대환,이채관,이헌,전진호,김정호,이채언 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.2

The workplace exposure of chemicals has steadily increased, therefore the concern for subsequent effect on reproductive outcome has been an important issue in occupational medicine. In previous studies, higher rates of spontaneous abortion, reduced fertility and menstrual disorder among women, and an impairement of sperm quantity and quality among men have been associated with a wide variety of chemical agents. This study was conducted to evaluate the effects of toluene, xylene and trichloroethylene(TCE) injection on the mRNA levels of GnRH, GnRH receptor and Pit-1 genes in male rats hypothalamus and pituitary and the effects on the plasma levels of FSH, LH, prolactin and testosterone. Sprague-Dawley male rats were divided into five groups of five each according to concentration of toluene, xylene and TCE. The rats were injected subcutaneously to 0, 50, 100, 200, 400 mg/kg body weight/day of toluene, xylene and TCE, respectively for 6 days. Rat brains were excised and hypothalamus and pituitary were separated. Reverse transcription-polymerase chain reaction (RT-PCR) and RNase protection assay(RPA) were used to evaluate the GnRH, GnRH receptor and Pit-1 mRNA levels. Plasma concentrations of FSH, LH, prolactin and testosterone were assayed by radioimmunoassay(RIA). The results were as follows; 1. GnRH, GnRH receptor and Pit-1 mRNA levels in toluene and xylene injected groups, and GnRH receptor mRNA levels in TCE injected group were lowered dose-dependently. Especially, GnRH receptor and Pit-1 mRNA levels in 200mg/kg of toluene injected group, and GnRH, GnRH receptor and Pit-1 mRNA levels in 400mg/kg of toluene injected group were significantly lower than control group (p<0.05). GnRH receptor and Pit-1 mRNA levels in 400mg/kg of xylene injected group, and GnRH receptor mRNA levels in 400mg/kg of TCE injected group were significantly lower than control group(p<0.05). 2. The plasma levels of prolactin and testosterone in 400mg/kg of toluene injected group, and LH in 100, 200 and 400mg/kg of xylene injected group, and testosterone in 400 mg/kg of TCE injected group were significantly lower than control group(p<0.05). In conclusion, we speculated that toluene and xylene affected reproductive system secondarily through hypothalamus-pituitary axis, and TCE affected directly through steroidogenesis. And we recommended that further study for assessment of the reproductive toxicity of mixed organic solvent exposures should be conducted.

중소기업형 통합일정관리 모듈의 개발

양성민,유대훈,송경동,강주선 경성대학교 생산기술연구소 1996 생산기술연구지 Vol.3 No.-

This research is performed for the purpose of helping small and medium enterprises in Pusan Korea through developing a Total Scheduling Module(TSM) considering their practical environments. The TSM consists of four sub-modules : a basic information sub-modules, a marketing information sub-module, an inventory control sub-module and a production control sub-module. And the TSM is developed for Network version under Client/Server environment.