고압 수증기 내에서 산화막 형성에 관한 연구

박경희,안순의,구경완,왕진석 충남대학교 산업기술연구소 2000 산업기술연구논문집 Vol.15 No.2

This paper shows experimentally that oxide layer on the p-type Si-substrate can grow at low temperature(500℃∼600℃) using high pressure water vapor system. As the result of experiment, oxide layer growth rate is about 0.19Å/min at 500℃, 0.43Å/min at 550℃, 1.2Å/min at 600℃ respectively. So, we know oxide layer growth follows reaction-controlled mechanism in given temperature range. Consequently, granting that oxide layer growth rate increases linearly to temperature over 600℃, we can expect oxide growth rate is 5.2Å/min at 1000℃. High pressure oxidation of silicon is particularly attractive for the thick oxidation of power MOSFET, because thermal oxide layers can grow at relatively low temperature in run times comparable to typical high-temperature. 1 atm conditions. In the condition of higher-temperature and high-pressure steam oxidation. the oxidation time is reduced significantly.

건축공사시방서에서의 KS규격의 국제인증방안에 관한 연구

김경식,이재섭,김용수,이규진,조용훈,최완철,전재열,이현수,구재동,이기환 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

The purpose of this research is make out construction specifications for International Construction. Using off-shore products incur cost increase and longer delivery term of construction. and inconvenient on International Construction. Expand the range of additional local products conforming to performance. Life Cycle Cost. maintainability. operability. user's acceptability, etc.. And this study is suggest the standard formats and the techniques for construction specification.

600Watt 급 LED 조명등의 열 해석 및 방열 설계

구경완(Kyoung-Wan Koo),한재섭(Jae-Sup Han),신부현(Buhyun Shin),김영식(Youngshik Kim),유봉조(Bong-Jo Ryu) 대한전기학회 2021 전기학회논문지 Vol.70 No.4

This paper deals with thermal flow analysis of LED lighting that is widely used in athletic facilities, underpass, household luminaries, etc. Recently, LED lighting is in the process of replacing the existing light sources based on the advantages of eco-friendliness, energy efficiency, high lifespan, etc. However, the heat generated from LED may lower the reliability of LED lighting by raising the temperature of chips. In this paper, it is verified that changing the form of the existing flat heatsink to a mechanically twisted structure without using a heat pipe for a 600-watt LED lighting is more effective for convectivity. Thermal analysis has been performed using a software, Solidworks-Flow Simulation 2017 version. The temperature analysis also has been performed according to the change of thickness of a heat sink at the room temperature. Through the analysis, average temperatures of the heatsink with 1.5 thickness are lower than that of the heatsink with 1.0 or 1.2 thickness.

정기건강진단에 대한 근로자의 만족도에 영향을 미치는 요인

구정완,임현우,이강숙,정치경,박정일,김보경 카톨릭대학산업의학센타 산업의학연구소 1999 韓國의 産業醫學 Vol.38 No.4

For the purpose of disclosing the factors associated with workers' satisfaction, the questionnaire survey on awareness, trust and satisfaction with periodic health examination, was carried out on 985 workers(male 708, female 277) who had taken periodic health examination in 38 small scale of workplace and 5 medium scale of workplace around Seoul area during the period from October, 1998 to February, 1999. The results were as follow: 1. Significant factors influencing the awareness of health examination were more than 40 years old and work duration more than 10 years. 2. Significant factors influencing the trust of health examination were more than 40 years old and absence of symptom at check-up and awareness. 3. Awareness influenced significantly on the satisfaction of health examination. 4. The awareness and trust of health examination were not associated with the scale of workplace but satisfaction of health examination showed relations with the medium workplace. In conclusion, this study suggested that health education should be reinforced and workers be voluntarily and actively participated in designing process to increase workers' satisfaction of periodic health examination.

Free Paper Session : Pancreatic Diseases ; The Efficacy Of Intensive Medical Treatments In Patients With Severe Acute Pancreatitis And Infected Necrotizing Pancreatitis

( Kyoung Hoon Rree ),( Dong Wan Seo ),( Ji Young Kim ),( Tae Yoon Lee ),( Sang Soo Lee ),( Sung Koo Lee ),( Myung Hwan Kim ) 대한소화기학회 2007 SIDDS Vol.9 No.-

Background/Aims: Necrotizing pancreatitis complicated with infection (IPN) is the main risk factor of morbidity and mortality in severe acute pancreatitis (SAP), and immediate surgical debridement of the septic focus have been widely accepted for this codition. However, surgical inter vention in systemic inflammatory state also contains a high mortality by itself and better treatment strategy is required. Our aim was to evaluate the efficacy of intensive non-surgical treatment in patients with SAP including INP. Methods: 101 patients [age (median, range, years): 51, 19-85; gender (M:F): 80:21] with SAP with necrosis (APACHE II score≥8, or Ranson`s score≥3, and pancreatic necrosis on CT scan) were retrospectively analyzed. IPN was confirmed by FNA. Intensive medical treatment including prophylactic antibiotics coverage, fluid resuscitation, organ preserving supportive measures, and percutaneous (PCD) or endoscopic drainage (ED) were applied. Surgery was conducted when there was no clinical improvement after the initial intensive medical treatment or immediate acute complications such as bowel perforation and panperitonitis were developed. Results: Mean values of Ranson`s score, APACHE II, and CT severity index were 4.86±1.88, 11.44±5.3, and 8.16±1.80, respectively. Among 101 patients, FNA and drainage procedures was performed in 51 patients, 47 PCD, 3 ED, and 1 combined PCD and ED. Forty-three patients received antibiotics only. Twenty-two patients required surgical intervention, 15 from drainage group and 7 from antibiotics only group. Microorganisms were identified in 38 patients and were treated with 23 PCD, 11 surgery with external drainage, 1 surgery only. The mortality rates of intensive medical treatment group and surgically treated group in SAP (INP) patients were 12.7% and 22.7% (4.3% and 16.6%), respectively. Conclusions: Intensive medical treatment comprising PCD and/or ED for INP showed favorable outcome in a substantial portion of patients.

Choledochal Cyst Associated the with Anomalous Union of Pancreaticobiliary Duct ( AUPBD ) Has a More Grave Clinical Course Than Choledochal Cyst Alone

(Hye Kyoung Song),(Myung Hwan Kim),(Seung Jae Myung),(Sung Koo Lee),(Hong Ja Kim),(Kyo Sang Yoo),(Dong Wan Seo),(Hyun Joo Lee),(Byeong Cheol Lim),(Young Il Min) 대한내과학회 1999 The Korean Journal of Internal Medicine Vol.14 No.2

N/A Objective:Previous pathObjective: Since choledochal cyst is frequently associated with the anomalous union of pancreaticobiliary duct(AUPBD), AUPBD has been regarded to be the etiologic factor of choledochal cyst. However, the clinical significance of AUPBD an patients with choledochal cyst has not been clearly defined. Therefore, to clarify the significance of AUPBD in choledochal cyst patients, we compared the clinical features of patients with choledochal cyst according to the presence or absence of AUPBD. Methods: Among 52 cases which were diagnosed as choledochal cyst out of 5,037 ERCP referrals between August 1990 and December 1996, we selected 44 cases, in which the pancreaticobillary junction was clearly visualized on cholangio-pancreaticography. These cases were divided into AUPBD-present group (n=28) and AUPBD-absent group (n=16). Clinical features were compared between the two groups. Furthermore, in AUPBD-present group, clinical data were also analyzed according to Kimura's classification of AUPBD. Results: In our study, AUPBD was associated with choledochal cyst in 28 (64%) cases. AUPBD was found only in type I and IV according to Todani's classification of choledochal cyst. There were no significant differences between the AUPBD-present group and the AUPBD-absent group in the incidence of gallstone disease, while the incidence of acute inflammation was 93% (26/28) in the AUPBD-absent group (p<0.01). Carcinoma developed only in the AUOBD-present group (9/28, 32%) (p<0.05). Pancreatic disorders (I.e. pancreatic stone, pancreatitis or pancreatic cancer) occurred in 12 of 28 cases in the AUPBD-present group(43%), while only in 1 of 16 cases in the AUPBD-absent group(6%)(p<0.05). Conclusion: AUPBD associated with choledochal cyst may have implications not only as a possible etiologic factor but also as an important factor that may affect the clinical course, surgical planning and prognosis. In cases with choledochal cyst, we should make an effort to evaluate the presence of AUPBD.

노인마취의 임상적 고찰

김완식,박동호,심재철,황영희,차영덕,유희구,서병태,장경덕,서정국,김유재 대한마취과학회 1983 Korean Journal of Anesthesiology Vol.16 No.2

In contrast to younger patients, old peoples frequently manifest more than one pathologic process, mainly degenerative diseases and neoplasia. Nearly all have some degree of arteri-osclerosis, even if this is not clinically diagnosed, and many have associated chronic cardiac, renal, hepatic, or pulmonary disease. The surgein and the anesthesiologist must see that their clincial decisions are tied to a physiologic understanding dased on exact quantification of the specific hemodynamic, respira-tory, renal, and metabolic factors which may play a decisice role in influencing the final outcome to a major operative procedure. From May 1972 to Dec 1980, the Department od anenthesiology, Hanyang University, Col-lege were analyzed clinically according to age, sex, department, phsical status, anesthetic technique and agent, anesthesia time, length of admission, laboratoty studise (chest X-ray, EKGm arterial blood gas), and postoprative complications (mortality and causes og death) the results are as follows: 1) Out of 25.857 anesthetized patients 517(2.0%) were over 64 years of age and 290 were males(56.1%) and 227 females(43.9%). 2) In the surgical group, 246 cases(47.6%) were from general surgery; 81 cases (15.7%), orthopedic surgry; 78 cases(15.1%), urology; and 67cases(12.9%), neurosugery respectively. 3) In the classification of physical status, 33 cases(6.4%) were class 1, 269 cases(52.0%) class 2, 181 cases(35.0%) class 3, 28 cases(5.4%) class 4, and 6 cases(1.2%) class 5, Emerg-ency cases were 137 cases(26.5%) and 380 cases(73.5%) eere elevtive. 4) Concernign premedication-150 cases(29.0%) were premedicated with atropine sulfate plus Valium and 93 cases had no premedication. 5) There were 425 cases of general anesthesia(82.2%) and 92 cases of regional anesthesia(17.8%). The major anesthetic was halothene, 362 cases(70.0%). The rechnic in 419 cases(81.0%) was circle type with endotracheal intubation. Anesthesia duration was within 1 hour for 70 cases(13.5%), within 2 hours for 158 cases(30.0%), and within 3 hours in 144 cases(27.9%). 6) Preoperative laboratory findings were as follows: The chest X-ray suggested that 199 cases(45.9%) were within nomal limits, 56 cases (12.9%) had hypertensive heart disease, 56 cases(12.9%) had pulmonary tuberculosis, and 38 cases(5.1%) had senile lung fibrosis. The EKG, which ws done on 85% of the patients, ravealed that 193 cases(44.0%) were within narmal limits, 61 cases(13.9%) showed left ventricual hypertrophy, and 38 cases(8.7%) had myocardial ischemia. In the preiperative arteral blood gas studies of 56 cases the results were almost all within narmal limits. 7) Postoperative complications were as follows: 52 cases showed wound infection or bleeding, 20 cases had pneumonia, and 18 cases atelectasis. There were a number of miscellaneous complications. 8) The overall mortality rate was 5.8%. The differnce of mortality rate related to the age was not statistically significant,(p>0.1) and the mortality rateed ot physical status was statistically significanct.(p<0.005). 9) As the cause of death-1 cases(36.7%) had transtentorial herniation, 2 cases(6.7%) sepsis, 2 cases(6.7%) hypobolemiam, and 1 cases(3.3%) had pulmonary edema.

유리규산 분진이 주물작업 근로자들의 환기기능에 미치는 영향

김경아,정치경,구정완 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.1

In order to study the exposure level of silica dust and the effects of silica dust on ventilatory function, respirable dust samples were collected by personal air samplers using NIOSH method 0500 from the selected foundry operations, and ventilatory function tests were performed on 209 male foundry workers and 239 male control subjects. Ventilatory indices such as forced vital capacity(FVC), one-second forced expiratory volume(FEV₁), ratio of FEV1 to FVC(FEV₁%), maximal mid-expiratory flow(MMF), peak expiratory flow rate(PEFR) and maximal expiratory flow at 25, 50 and 75% of expired FVC(FEF25, FEF50, FEF75) were obtained by analyzing forced expiratory spirogram and maximal expiratory flow-volume curve which were simultaneously measured by Vitalography in standing position. The results were as follows: 1. The average quartz concentrations of respirable dust were the highest in melting operation(0.079㎎/㎥) and followed by molding operation(0.051㎎/㎥), finishing operation(0.041㎎/㎥) and coremaking operation(0.023㎎/㎥) in the descending order. 2. No significant differences for mean values of all ventilatory indices expressed as percent of predicted value were demonstrated between smokers and nonsmokers in foundry workers and control subjects. 3. Mean values of all ventilatory indices except FVC of foundry workers were significantly lower than those of control subjects. 4. Mean values of FEV₁%, MMF, FEF25, FEF50, FEF75 expressed as percent of predicted value tended to decrease with increasing cumulative dust exposure. 5. In foundry workers, proportions of workers with low MMF, FEF50 and FEF75 were markedly higher than those with other indices, and were significantly increased with increasing cumulative dust exposure. 6. In foundry workers, 2 workers(1.0%) were diagnosed as silicosis and the profusion of radiographic opacities were category 1/0 and q type. With the above considerations in mind, it suggested that increasing exposure of silica dust be associated with progressive deterioration in ventilatory function of an obstructive nature and that MMF, FEF50 and FEF75 be more sensitive indices in the detection of the early obstructive changes of air flow of workers exposed to silica dust.

근로자 건강증진 실천에 영향을 미치는 요인

김은경,김병권,박종태,김형렬,구정완 대한산업의학회 2007 대한직업환경의학회지 Vol.19 No.1

목적: 본 연구에서는 사업장 근로자들의 건강증진 실천 현황을 알아보고, 실천에 있어서 장애요인이 되는 것이 무엇인지 파악하여 효율성과 실효성이 있는 사업장 건강 증진 사업의 발전방향을 모색하는데 그 목적을 두었다. 방법: 경기도 K대학병원, 서울시의 C대학병원에서 보건관리대행사업 또는 국고지원사업을 받고 있는 사업장 중 서울경기지역의 사업장 규모별 비율을 고려하여 사업장 규모별로 사업장 근로자수의 20%를 대상으로 사업장 건강증진사업 현황에 대한 설문조사를 시행하였다. 결과: 대상자 중 건강증진 활동을 하고 있는 비율은 51.3%로 나타났으며 건강증진을 실천하고 있는 경우, 금연을 하고 있다는 응답이 가장 많았고 실천의 계기로는 TV 또는 언론매체의 자극에 의한 경우가 33.4%, 건강진단에서 이상 소견 및 건강이상을 느껴서 시작한 경우가 22.1%였다. 근로자들이 가장 필요로 하는 사업장내 건강증진프로그램은 운동이 41.9%로 가장 높았고, 스트레스 관리가 그 뒤를 이었다. 건강증진사업에 대한 기대 정도는 상당히 효과가 있다고 응답하거나 어느 정도 효과가 있을 것이라고 응답한 경우가 84.8%로 건강증진사업에 대하여 근로자들이 긍정적으로 평가하고 있으며 기대도가 높은 것을 확인할 수 있었다. 건강증진 실천 여부에 영향을 주는 요인은 근로자의 건강상태, 직무자율성 등으로 나타났다. 결과: 개인의 의지 부족이나 시간, 비용 등이 건강증진 활동의 장애요인으로 작용하고, 근로자의 건강상태나 직무자율성 등이 건강증진 실천에 영향을 주고 있는 것으로 나타났다. 장애요인은 개인의 건강증진 실천 의지를 북돋아 주기 위한 사업장 단위의 근로자의 건강증진 활동의 유지 및 지지를 위한 프로그램 강화를 통해 극복할 수 있다. 또한 사업주의 시간적 배려, 사업주와 국가의 경제적 지원책, 지역사회 공공 체육시설 이용 개방 등을 고려할 필요가 있다. 건강증진 활동 실천집단과 비실천집단에 연령, 학력, 결혼여부, 연봉, 근무 일정 등의 차이가 있었는데 이를 통해 건강관리에 있어 시간, 경제, 개인의 생활환경이나 지식수준이 관여한다고 볼 수 있다. 결론: 이상의 결과를 통해 볼 때 건강증진 활동의 효과에 대해서 84.8%가 긍정적으로 평가하고 있다는 것을 알 수 있다. 현재 사업장 건강증진 활동은 금연이나 운동을 중심으로 이루어지고 있으나 본 연구 결과 운동이나 스트레스 관리에 대한 요구도가 높은 것을 확인할 수 있었다. 이에 따라 근로자들의 운동을 위해 사용이 용이한 운동 시설을 마련해야 하며 본 연구에서 긍정적으로 평가 되었던 바와 같이 사업장 밖에 공공 건강증진시설의 확대 방안을 강구하고, 스트레스 관리를 위한 구체적인 방안을 마련해야 할 것이다. Objective: The aim of this paper was to develop efficient and practical health promotion strategies in the workplace by investigating both the present status of health promotion and the barriers to its practice. Methods: A questionnaire was administered to 20% of industrial workers in the workplaces which receives the health care agency enterprise or are supported by a grant from the national treasury, K University Hospital in Gyeong-Gi province, and C University Hospital in Seoul. Results: According to the questionnaire survey, 51.3% workers were practicing health promotion activities and smoking cessation was the most common method among them. Regarding the factors that prompt workers to commence health promotion activities, TV or the mass media had a 33.4% effect, followed by a 22.1% effect for an abnormal finding at regular health screening. The most necessary health promotion activity in the workplace was exercise (41.9%), followed by stress management. When asked about their expectations of the health promotion program, 84.8% of the respondents answered that they expected it to be significantly or somewhat effective. Factors affecting the health promotion activities of workers were worker' s health status and job control. Conclusions: This study demonstrated that workers evaluate health promotion activities positively and that some workers are unable to participate in these activities despite their willingness to do so due to the barrier of circumstances. To encourage worker' s participation, the government and employers should remove barriers.

뇌전증 환자의 업무 적합성 평가에 관한 증례

김경한(Kyoung-Han Kim),최민(Min Choi),김세은(Se-Eun Kim),장태원(Tae-Won Jang),김형렬(Hyoung-Ryoul Kim),구정완(Jung-Wan Koo) 대한직업환경의학회 2012 대한직업환경의학회지 Vol.24 No.3