면진구조의 동적특성에 따른 구조물의 진동거동에 관한 연구

김용주,강병두,전대한,김재웅 동아대학교 건설기술연구소 2001 硏究報告 Vol.25 No.1

Base isolation systems consists essentially of the installation of mechanisms which decouple the structure, and/or its contents, from potentially damaging earthquake-induced ground, or supports, motions. This decoupling is achieved by increasing the flexibility of the system, together with providing appropriate damping. In this paper, the effectiveness of base isolated structures under a variety conditions are evaluated and compared. The results of this study are as follow; Increasing the natural period and the damping capacity of the base isolated structures decreases structure's response to earthquake load. Base isolation can enhance the seismic performance of structures by increasing the fundamental period of the structure to beyond the energy-containing periods of earthquake motion, and by providing additional damping to dissipate motions that do develop. If period of base structure is longer than that of main structure, the natural period of combined structure approaches to that of base structure.

비선형 약산법에 의한 지진응답평가 비교

신기영,강병두,김재웅 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

In an effort to develop design methods based on performance it is clear that the evaluation of the inelastic response is required. The methods available to the design engineer today are nonlinear time history analyses, or monotonic static nonlinear analyses, or equivalent static analyses with simulated inelastic influences. Some codes proposed the capacity spectrum method based on the nonlinear static(pushover) analysis to determine earthquake-induced demand given the structure pushover curve. This procedure is conceptually simple but iterative and time consuming with some errors. This paper considers a nonlinear direct spectrum method to evaluate seismic performance of structure, without iterative computations, given the structural initial elastic period and yield strength from the pushover analysis, especially for multi degree of freedom structures. The purpose of this paper is to investigate accuracy and confidence of this method from a point of view of various earthquakes.

지진응답평가를 위한 비선형 약산법의 오차해석

박진화,강병두,노필성,김재웅 동아대학교 환경문제연구소 2003 硏究報告 Vol.25 No.2

Recently, a variety of methods are proposed to solve the problems shown in a existing performance-based design of structure. The most accurate one among analysis methods for the performance evaluation of structure is nonlinear time history analysis. However, the approximate analysis methods in aspect of practicality and simplicity are needed. Even though there are linear capacity spectrum method and nonlinear capacity spectrum method through nonlinear static analysis as the representative approximate methods, a repetitive calculation process is consumed and the result is also likely to be inaccurate. Therefore, this research presents nonlinear direct spectrum method which directly enables nonlinear maximum response to derive, after obtaining the yielding strength and the frequency of structure from pushover curves, without going through a series of calculation processes. Also, it is proposed to compare and examine the accuracy and practicality through an example structure.

다양한 구조특성에 따른 비선형 약산법들의 비교

신기영,강병두,김재웅 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

In performance-based design methods, it is clear that the evaluation of the nonlinear response is required. Some codes proposed the capacity spectrum method(CSM) based on the nonlinear static analysis to determine earthquake induced demand given the structure pushover curve. This procedure is conceptually simple but iterative and time consuming with some errors. The nonlinear direct spectrum method(NDSM) is proposed and studied to evaluate nonlinear response of structures, without iterative computations, given by the structural linear vibration period and yield strength from the pushover analysis, especially for shear buildings system. The purpose of this paper is to compare accuracy of approximate nonlinear methods with respect to various structure characteristics.

전신성 홍반성 낭창의 임상적 고찰

신영태,김종학,장윤경,양종오,구영선,강민규,황평주,나기량,이강욱,서광선 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

The epidemiology, diagnostic criteria, clinical features, symptoms and signs laboratory findings, kidney pathology, and clinicopathologic correlation of systemic lupus erythematosus(SLE) were analyzed. The 63 patients studied were managed at the Department of Internal medicine, CNUH, from January 1983 to December 1997. Kidney biopsy was performed in 53 patients out of 63 patients with SLE. The results were as follows: 1. The ratio of male to female was 1:26. They were 12 to 71 years old and mean age was 32.1 years old. The peak age incidence was 4th decades(30%). 2. The most frequent chief complaint on admission was generalized edema. Most patients complain two or more symptoms. 3. Immunologic and renal disorders were the most frequently observed in the ARA criteria of SLE. And the positive ANA, hematologic disorder, malar rash, and arthritis, were observed in order of frequency. 4. Among the 53 patients with renal biopsy, 30 patients revealed class Ⅳ lupus nephritis(56%), class II in 12 patients(23%), class V in 8 patients(15%) and class III in 2 patients(6%). 5. The cases of lupus nephritis represented as nephrotic syndrome were high in the class IV with 68% and class V with 86%. 6. Of 30 patients who can be followed up, 5 patients resulted in death(17 % of mortality). They "were 14 to 57 years old and mean age was 28 years old. Follow up duration were from 1 month to 6 years and 3 months, and mean duration was 1 year and 1 month, but 3 cases 7. The causes of death were as follows: Two cases were due to seizure and coma resulted from CNS involvement. One was sepsis due to miliary the & pneumonia. One was dilated cardiomyopathy and heart failure due to cardiac ac involvement. And the other one was sepsis and acute renal failure resulted from cellulitis. 8. Prednisolone was used in all patients basically, and methyl-prednisolone pulse therapy, antimalarials and alkylating agents were used in some cases. In the cases of combined therapy, the activity of SLE was well controlled.

성인 급성 신부전의 원인 및 예후인자 분석

구영선,장윤경,양종오,강민규,황평주,김종학,나기량,이강욱,신영태 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.2

Acute renal failure is a frequent complication in hospitalized patients and is strongly related to the mortality. The Clinical outcome and prognostic factors of acute renal failure(ARF) have been analyzed by many authors. The present study describes the etiologic and clinical aspects, as well as other factors related to mortality. All the patients suffering from acute renal failure admitted during the period of January 1993 - August 1998 were included in the study. The average age of the patients was 52±17 years and mortality rate was 24%. The causes of acute renal failure were hemorrhagic fever with renal syndrome(HFRS), sepsis, renal hypoperfusion, urinary tract obstruction, acute tubular necrosis, etc. The etiology of ARF was a significant prognostic factor on mortality in ARF. Other significant prognostic factors were oliguria, organ failure, use of vasoconstrictors, hypotension, serum bicarbonate, premorbid conditions, sepsis, neurologic complications, gastrointestinal bleeding. On the other hands, operation, sex, anemia, thrombocytopenia, hypoalbuminemia, BUN, serum creatinine, and hyperkalemia were not significant factors for the mortality. We conclude that major prognostic factors of acute renal failure arc premorbid conditions, sepsis and multiorgan failure, and they are responsible for persistent high mortality of acute renal failure despite of advances of medical care.

Dietary Exposure to Transgenic Rice Expressing the Spider Silk Protein Fibroin Reduces Blood Glucose Levels in Diabetic Mice: The Potential Role of Insulin Receptor Substrate-1 Phosphorylation in Adipocytes

박지은,정연재,박준범,김혜영,유영현,이광식,양원태,김도훈,김종민 한국발생생물학회 2019 발생과 생식 Vol.23 No.3

Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance (IR). T2DM is correlated with obesity and most T2DM medications have been developed for enhancing insulin sensitivity. Silk protein fibroin (SPF) from spiders has been suggested as an attractive biomaterial for medical purposes. We generated transgenic rice (TR) expressing SPF and fed it to diabetic BKS.Cg-m+/+Leprdb mice to monitor the changes in blood glucose levels and adipose tissue proteins associated with energy metabolism and insulin signaling. In the present study, the adipocyte size in abdominal fat in TR-SPF-fed mice was remarkably smaller than that of the control. Whereas the adenosine monophosphate-activated protein kinase (AMPK)-activated protein kinase and insulin receptor substrate 1 (IRS1) protein levels were increased in abdominal adipose tissues after TR-SPF feeding, levels of six-transmembrane protein of prostate 2 (STAMP2) proteins decreased. Phosphorylation of AMPK at threonine 172 and IRS1 at serine 307 and tyrosine 632 were both increased in adipose tissues from TR-SPFfed mice. Increased expression and phosphorylation of IRS1 at both serine 307 and tyrosine 632 in adipose tissues indicated that adipocytes obtained from abdominal fat in TR-SPF-fed mice were more susceptible to insulin signaling than that of the control. STAMP2 protein levels decreased in adipose tissues from TR-SPF-fed mice, indicating that STAMP2 proteins were reducing adipocytes that were undergoing lipolysis. Taken together, this study showed that TR-SPF was effective in reducing blood glucose levels in diabetic mice and that concurrent lipolysis in abdominal adipocytes was associated with alterations of AMPK, IRS1, and STAMP2. Increased IRS1 expression and its phosphorylation by TR-SFP were considered to be particularly important in the induction of lipolysis in adipocytes, as well as in reducing blood glucose levels in this animal model.

HOG-MLCM을 이용한 향상된 보행자 검출 알고리즘 설계

김평강(Pyeong-Kang Kim),김도영(Do-Young Kim),김형헌(Hyeong-Heon Kim),김태우(Tea-Woo Kim) 한국정보과학회 2015 한국정보과학회 학술발표논문집 Vol.2015 No.6

Fabrication and characterization of NbTi-Au-NbTi Josephson junctions

Pyeong Kang Kim,Heechan Bang,Bongkeon Kim,Yong-Joo Doh 한국초전도저온학회 (구 한국초전도저온공학회) 2022 한국초전도저온공학회논문지 Vol.24 No.4

Micro/nano-hybrid lens for enhancing light extraction using micro-milling and anodic aluminium oxide (AAO)

Kim, Shin Hyeong,Kim, Min Gu,Kang, Jeong Jin,Lee, Pyeong An,Kim, Bo Hyun,Cho, Young Hak IOP 2016 Journal of micromechanics and microengineering Vol.26 No.1

<P>In the recent past there has been much research towards increasing the transmission of light in optical systems by reducing the Fresnel reflection of radiation, as the reflection of light from surfaces seriously decreases the performance of an optical device. These drawbacks have been overcome by mainly two methods, which are anti-reflective coating and anti-reflective nanostructure formation.</P> <P>In this study, we developed a simple fabrication process for Al micro/nano hybrid lens (MNHL) moulds for efficient light extraction using micro-milling and anodic aluminum oxide (AAO). From these moulds, two different types of polymer MNHL were fabricated using hot-embossing; one was a polymer MNHL that was covered with nanostructures over the entire surface, and the other was one for which only the microlens surface was covered with nanostructures. Two different types of polymer MNHLs were evaluated and compared with each other concerning the light extraction performance. The MNHL with nanostructures only on the microlens surface exhibited a higher light extraction performance than the other by 20.7%. It is expected that the fabricated MNHL can be used for the amplification of small signals when observing the presence of bio-molecules dyed with a fluorescent material.</P>