Box Girder 해석 프로그램의 개발

조용덕,이용재 건국대학교 산업기술연구원 1995 건국기술연구논문지 Vol.20 No.-

박스 거더는 현수교나 사장교와 같은 교량의 건설에 많이 사용되고 있다. 박스 거더의 거동은 Bending, Shear, Warping torsion, Distortion으로 이루어진다. 박스 거더 거동의 해석이 일반적인 거더의 해석보다 난이해서, 이를 쉽게 해석할 수 있는 컴퓨터 프로그램의 도입이 필요하게 되었다. 프로그램을 계속 발전시킬 수 있도록 박스 거더의 기본이론을 정리하고, 3절점 1요소의 박스 거더 기본모델을 가지고 유한요소법으로 강성 매트릭스를 구축하여, 박스 거더 거동해석 컴퓨터 프로그램을 만들었다. 프로그램의 검증을 위해 타논문의 모델을 이용하여 예제 분석을 실시하였고, 정확한 결과값을 얻을 수 있었다. Thin walled box girders are widely used in modern bridge construction such as suspension and cable-stsyed bridges. This walled beam theory including warping torsion, distortion and shear effect, is combined with finite element method. Three node beam element which has nine degree of freedom in each node is incorporated into computer program. Example box girders are analyzed by this program.

일개 자동차 부품공장 근로자에서 초음파로 측정한 수근관 형태와 수근관증후군 위험도

김덕수,정해관,임현술,권용욱,이종민,조대현,최대섭 大韓産業醫學會 2002 대한직업환경의학회지 Vol.14 No.3

목적 : 일개 사업장의 생산직 근로자를 대상으로 손목 계측치 및 초음파를 이용한 수근관 계측치의 상관성 분석을 통하여 수근관증후군 발생에 관여하는 개인의 감수성 및 위험요인을 파악하여 생산직 근로자들의 수근관증후군 예방에 활용하고자 본 연구를 수행하였다. 방법 : 경주시에 위치한 자동차 방음재를 생산하는 사업장에 생산직 근로자 남자 24명, 여자 11명 등 총 35명을 대상으로 2000녀 4월과 2000년 10월 반드시 각 설문조사, 이학적검사, 전기진단검사를 실시하였으며, 2000년 10월에는 초음파를 이용한 수근관계측도 실시하였다. 결과 : 수근관증후군의 신체계측 요인에 따른 분석에서는 수근관 전치/폭 비가 0.17 미만인 군에 비하여 0.17 이상인 군에서 통계적으로 유의하게 높았다(p<0.05). 총 수근관 면적(두께×폭)은 300 ㎟이상인 군에 비하여 300㎟ 미만인 군에서 통계적으로 유의하게 높았다(p<0.05). 성별을 통제변수로 처리한 신체 계측치간 상간 분석에서는 수근관폭은 전기진단 검사와 음의 상관성을 보였으며, 수근관 두께는 전기진단 검사와 양의 상관성을 보였다. 수근관 두께/폭 비는 전기진단 검사와 양이 상관성을 보였으며, 수근관비 전치/두께 비는 전기진단 검사 결과와 음의 상관성을 보였다. 하부 수근관 면적[폭×(두께-전치)]은 전기진단 검사와 양의 상관성을 보였으며, 상부 수근관 면적(폭×전치)은 전기진단 검사와 음의 상관성을 보였다. 또한 수근관 전치의 상대적 비가 클수록 수근관증후군의 회복이 유의하게 좋았다. 결론 : 수근관증후군은 수근관 폭이 좁을수록, 수근관 두께가 두꺼울수록, 수근관 전치가 작을수록 수근관증후군 위험도가 증가한다. 저자들은 초음파를 이용한 수근관 형태의 측정은 수근관증후군의 발생의 내적 요인에 대한 중요한 정보를 제공하면 수근관증후군 발생 및 회복의 개별적 위험요인을 예측하는데 중요한 근거를 제공하는 것으로 판단하였다. Objectives: This study was conducted to evaluate individual susceptibility to carpal tunnel syndrome (CTS) by ultrasonographic measurement of the carpal tunnel configuration in workers doing repetitive work. Methods: The study subjects consisted of 24 male and 11 female workers in a soundproof material manufacturing company in Gyeongju. We conducted a self-reported questionnaire survey, a physical examination and an electrodiagnostic study (EDS) in April 2000. After the examination, jobs were rearranged for workers with CTS. A follow up physical examination. EDS, and measurement of the carpal tunnel by ultrasonography was done six monsths later. Results: Of those studied. prevalence or CTS was 63.6/100 persons among women and 29.2/100 persons among men. Mean depth and width of wrist was shorter in those with CTS compareal to the controls (p<0.05). The risk of CTS was higher in workers whose carpal tunnel ratio (displacement/width) was 0.17 or higher (OR 7.13, 95% confidence interval 1.18-43.1), and in workers whose carpal tunnel area was less than 300 ㎟ (OR 8.00, 95% confidence interval 1.18-68.5). Carpal tunnel depth and depth/width ratio had a positive correlation with motor latency of the median nerve and median-ulnar sensory latency difference (p<0.05). whereas the carpal tunnel width. displacement/depth ratio, and area (width×displacement) had a negative correlation with median nerve latencies after adjusting for gender. Workers who showed an improvement in the clinical stage of CTS after job rearrangement had a significantly lower carpal tunnel displacement/width ratio and displacement/depth ratio. They also had smaller upper carpal tunnel area (width×displacement) and larger upper carpal tunner\l area [(depth-displacement)×width] than the controls (p<0.05). Conclusions:Ultrasonographic measurement of the carpal tunnel is a good predictor of susceptibility and prognosis of CTS in workers doing repetivive work.

급성 근골격병변의 치료에 이용한 국소도포용 PIROXICAM GEL의 효과

김기용,조덕연,김영태 최신의학사 1985 最新醫學 Vol.28 No.6

복합열화환경 하에서의 단면복구재의 철근부식특성 평가에 관한 실험적 연구

김영덕,박종호,조봉석,김용로,권영진,김무한 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

The duties of the restorative material are to bear up against stress and to protect reinforcement corrosion. So the restorative material are estimated by various kinds of strength, permeability and etc. But to evaluate performance of the restorative material accurately, it is necessary to estimate their reinforcement corrosion directly in environment of combined deterioration. In this study, to evaluate performance of restorative materials, we compare their properties in terms of compressive and bending strength and permeability of water and air with actual reinforcement corrosion like ratio of corrosion area, weight reduction and corrosion velocity of steel bar under environment of complex deterioration. The results showed that strength and permeability of restorative materials are similar but their reinforcement corrosions are very different. And there is a case that strength and permeability of restorative material are better than normal concrete but reinforcement corrosions are worse.

극단값分布의 母數에 대한 붓스트랩 推定

姜錫福,趙容德 嶺南大學校 基礎科學硏究所 1996 基礎科學硏究 Vol.16 No.-

We propose the estimators of the parameters of the extreme value distribution when the scale parameter is known and unknown. We compare the proposed estimators of the parameters with the maximum likelihood estimator (MLE) in the extreme value distribution in the sense of mean square errors (MSE) through Monte Carlo method.

지속성 외래복막투석 환자들의 예후에 영향을 미치는 요인들에 관한 고찰

권혁만,김찬덕,조지형,장민화,최혁준,이현철,박자용,박선희,김용림 대한신장학회 2004 대한신장학회잡지 Vol.23 No.2

비화농성 삼출성 복수를 동반하는 질환에서 복막 침생검의 진단적 의의

정종훈,서용태,오덕환,채종구,정춘해,조건국 朝鮮大學校 附設 醫學硏究所 1986 The Medical Journal of Chosun University Vol.11 No.1

Percutaneous needle biopsies of peritoneum with Abrams needle and Cope needle were done un 64 patients with non-purulent exudative ascites, who was admitted to the department of internal medicine, Chosun University hospital, from January 1978 to Deccmber 1983. The diagnostic significance and safety of the needle biopsy was estimated. The results were as follows. 1. Adequate peritoneal tissue for pathological diagnosis was obtained in 53 cases(82.8%) among 64 cases. (Abrams needle 84.8%, Cope needle 80.6%) 2. Definitive diagnosis was obtained in 31 cases among 53 cases (58.6%). (Tuberculosis 23 cases, malignancy 8 cases). 3. As compared final diagnosis with biopsy result, the rate of final diagnosis corresponding with biopsy diagnosis was 58.8% in tuberculosis and 26.3%, in malignancy, but the rate of biopsy diagnosis corresponding with final diagnosis was 100% in both tuberculosis and malignancy. 4. Cases of chronic non-specific inflammation which were diagnosed by biopsy were 13cases(24.5%)among 53 cases, and among these cases, tuberculosis was 69.2% and malignancy 30.8% on final diagnosis and among 53 cases, histologically normal was 9 cases(16.9%) of which 33.3% was tuberculosis and 66.7% was malignancy on final diagnosis. 5. Of the malignant cases on final diagnosis, Positive cytologic examination of ascitic fluid was 16.7% 6. Primary losions of cancerous peritonitis were stomach cancer (38.9%) hepatocellular cancer(22.2%) colon cancer (11.1%) ovarian cancer (11.1%) Pancreatic cancer (5.6%). 7. Complication of percutaneous peritoneal biopsy was local swelling with leakage of ascitic fluid and the accident rate were 36.4,% in Abraham needle and 3.2% in Cope needle.

Sustainability of highly porous oil adsorbents based on biodegradable polycaprolactone(PCL)

Yong Uk Cho(조용욱),Seung Jae Lee(이승재),Hee Kyeong Kim(김희경),Nae-un Kang(강내운),Young-Sam Cho(조영삼),Kyoung Duck Seo(서경덕) 대한기계학회 2020 대한기계학회 춘추학술대회 Vol.2020 No.12

Reusability evaluation of biodegradable PCL (polycaprolactone) oil absorbent with porous structure

Yong Uk Cho(조용욱),Hee Kyeong Kim(김희경),Nae-Un Kang(강내운),Seung Jae Lee(이승재),Young-Sam Cho(조영삼),Kyoung Duck Seo(서경덕) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4

Oil leakage is one of the problems in pollution. To solve this problem, oil absorbent has been used. But the absorbent containing oil is landfilled as waste, and it causes serious problems since it takes a long time to degrade in the nature. Recently, a few studies have been taking place in reducing time by changing materials, but still have a challenge. In this study, an oil absorbent was fabricated using PCL (a biodegradable material that can be degraded by bacteria and fungi), via particle leaching method, and the ratio of PCL and salt was maintained at 1:6 wt%. To examine the porous structure inside, SEM images was captured. Moreover, oil absorption capacity was experimentally determined. Furthermore, to separate oil from absorbent, different oil removal methods (simple washing, simple melting, combination of washing and melting) were tested and the remaining oil contents were analyzed by TGA (thermo-gravimetric analysis). As a result, the absorbent made of PCL has enough ability to absorb oil and it is sustainable enough to allow 20 cycles. Also melting method show smallest the remaining oil contents among other removal methods.

Oil-collecting of biodegradable PCL(polycaprolactone) oil absorbent

Yong Uk Cho(조용욱),Hee Kyeong Kim(김희경),Nae-Un Kang(강내운),Seung-Jae Lee(이승재),Young-Sam Cho(조영삼),Kyoung Duck Seo(서경덕) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.6

Oil is one of the important resources in the world since industrial revolution. However, in the case of an oil spill, most of the oil could become tragic waste, and it could adversely affect the environment. Research to solve this problem has been actively carried out in recent years, and most of them have been studied to make a material that absorbs oil. Notwithstanding, there are still areas to be challenged. In this study, an experiment was conducted to extract the oil in the absorbent which is made by PCL (polycaprolactone), a biodegradable material. The oil absorbent was made using method called SLUP(salt leaching using powder) and its oil absorbing ability was investigated. To remove residual oil from the absorbent after squeezing process, different residual oil removal methods(simple washing, simple melting, sonication in ethanol or isopropyl alcohol) were demonstrated. Moreover, the amount of residual oil was confirmed by using TGA (thermogravimetric analysis). As a result, it was found that the lowest amount of residual oil remained when the melting method was opted comparing to other methods. [그림 본문 참조]