트러스 형태에 따른 스태거드트러스 골조시스템의 내진성능 평가

홍윤수,유은종,나창순 한국전산구조공학회 2017 한국전산구조공학회논문집 Vol. No.

본 연구의 목적은 트러스의 형태를 바꿔가며 엇갈린 트러스(STF) 시스템의 내진성능을 평가하는 것이다. 예제 구조물은 10층의 철골조 사무실 건물이며, 시스템별로 각각 프랫트러스, 하우트러스, 와렌트러스, 케이트러스와 비렌딜트러스를 적용 하였다. 중력하중, 풍하중, 지진하중을 고려한 구조해석을 실시하여 부재에 높은 DCR을 만족하는 단면을 산정한 후 고유주 기, 밑면전단력과 층간변위를 산출하였다. 그 후, 역량스펙트럼법을 통해 1.2배의 설계지진(DE)과 최대고려지진(MCE)에 대 한 성능점을 산정하고, STF 시스템의 항복여부 및 소성힌지의 분포를 파악하여 구조기준에서 제시한 목표성능수준을 만족 하는지 살펴보았다. 평가 결과, 모든 시스템이 해당 목표성능수준을 만족하였으며, 시스템의 경제성 및 효율성을 따져보았을 때, PR10이나 VR10이 가장 적합한 것으로 나타났다. The purpose of this study is to evaluate the seismic performance of Staggered Truss Frame(STF) system while changing a shape of truss. The model of this project is a office building of ten floors with Pratt, Howe, Warren, K and Vierendeel truss system applied on each model. Next step is to select the section of elements which satisfy the highest demand capacity ratio by structure design considering gravity load, earthquake load and wind load and then calculate natural period, base shear and story drifts. On the basis of these values, Capacity Spectrum Method(CSM) shows the plastic behavior of STF system such as performance point of Design Earthquake(DE) and Maximum Considered Earthquake(MCE), yield state, plastic hinge etc. to be compared with other truss systems. As a result, Vierendeel STF system especially was found to have the highest strength and stiffness to the corresponding earthquake and all the models for each truss shape fulfilled the target performance level.

링크의 초과강도 예측에 의한 편심가새골조의 역량설계

홍윤수,유은종,Hong, Yunsu,Yu, Eunjong 한국전산구조공학회 2021 한국전산구조공학회논문집 Vol.34 No.5

편심가새골조(EBF)의 역량설계법에 의하면, 링크가 완전항복 및 변형경화 상태일 때 기둥, 링크외부보, 가새(비소산 부재)는 탄성거동해야 한다. 현행 AISC 341은 역량설계에 필요한 변형도경화계수(SHF)를 1.25로 제시하고 있으나, 실제로 건물이 고층 규모일수록 모든 링크가 이처럼 동등한 수준의 초과강도에 도달할 가능성은 매우 낮아진다. 본 연구에서는 링크의 SHF를 정밀하게 예측하는 방법을 제안함으로써, 역량설계법의 목적을 달성하면서 구조물량을 절감하고자 하였다. 제안한 방법의 효과를 검증하기 위해 선형해석을 2회 수행하여 SHF를 예측하고, 이를 비선형 해석결과와 비교하였다. 다음으로 비선형 해석에 의한 응답을 분석하여 구조물의 한계상태에서 비소산 부재들의 항복 여부를 확인하였다. 그 결과, 본 연구의 방법으로 설계된 구조물은 링크의 SHF를 정확히 예측함으로 인해 물량이 큰 폭으로 절감되었으며, 비소산 부재들도 모두 탄성상태를 만족하는 것으로 나타났다. According to the capacity design of eccentrically braced frames (EBFs), non-dissipative members such as columns, link-exterior beams, and braces must remain within the elastic region when a fully-yielded and strain-hardened link transmits force to them. The current AISC 341 standard suggests a strain-hardening factor (SHF) of 1.25 for a link under capacity design, regardless of its properties. However, all the links in an EBF are not likely to yield simultaneously to the extent to which the overstrength corresponding to 1.25 times their expected strength is attained, especially for high-rise buildings. Considering this phenomenon, a technique to predict the SHF of links at the limit state of the structure is proposed in this paper. The exact prediction of the links' SHF could save structural quantities dramatically while achieving the principle of capacity design. To validate the effectiveness of this technique, SHF values predicted by conducting linear analysis were compared with those evaluated by nonlinear analysis. Furthermore, the maximum demand-to-capacity ratios of the non-dissipative members were calculated to verify whether they would remain elastic at the limit state of the structure. Consequently, EBFs designed by the proposed method showed substantially economical quantities through the exact prediction of the SHFs, and the intention of capacity design was successfully achieved.

다목적 최적화 기법을 이용한 편심가새골조의 역량설계

홍윤수,유은종 한국전산구조공학회 2020 한국전산구조공학회논문집 Vol.33 No.6

본 연구에서는 철골편심가새골조 시스템을 대상으로 다목적최적화기법을 통해 설계를 수행하고 그 결과를 분석하였다. 최적화 설 계를 위해 유전 알고리즘의 일종인 NSGA-II를 활용하였다. 여기서, 목적함수는 이율배반적 관계를 갖는 구조물량과 층간변위로 하여 최소화되고, 제약조건에는 구조기준에서 요구하는 내력비, 링크의 회전각 등을 포함하였다. 제약조건은 최적화 알고리즘 내에서 각 항목을 위반할수록 목적함수 값을 크게 증가시키는 벌금함수의 형태를 가지고 있다. 설계기준에서 EBF 시스템의 설계규정은 링크 부재만 항복이 허용되며 나머지 부재는 링크 항복 시 발생되는 부재력을 탄성상태에서 견디도록 의도한 역량설계법에 기초한다. 그러나 최적화를 통해 도출된 결과 중 일부는 구조기준의 설계조항은 만족하지만 특정층 링크에 소성변형이 집중되어 연약층을 형성함 으로써 기준에서 의도하는 역량설계의 원칙을 위배하는 결과가 나타났다. 이를 해결하기 위해 모든 링크의 전단 초과강도계수 중 최 대값이 최소값의 1.25배를 넘지 않도록 하는 제약식을 추가하였다. 새로운 제약식을 추가한 경우 모든 최적해는 설계기준과 역량설계의 원칙을 준수하는 것으로 나타났다. 모든 설계안에서 보 경간에 대한 링크의 길이비는 전단링크의 범주에 해당하는 10% ~ 14%였다. 전체적으로 설계안들은 링크의 초과강도 계수비가 가장 지배적인 제약으로 작용하였으며, 구조기준의 요구사항 중 층간변위와 내력비 등의 항목에서 허용치에 비해 매우 보수적으로 설계되었다. The structural design of the steel eccentrically braced frame (EBF) was developed and analyzed in this study through multiobjective optimization (MOO). For the optimal design, NSGA-II which is one of the genetic algorithms was utilized. The amount of structure and interfloor displacement were selected as the objective functions of the MOO. The constraints include strength ratio and rotation angle of the link, which are required by structural standards and have forms of the penalty function such that the values of the objective functions increase drastically when a condition is violated. The regulations in the code provision for the EBF system are based on the concept of capacity design, that is, only the link members are allowed to yield, whereas the remaining members are intended to withstand the member forces within their elastic ranges. However, although the pareto front obtained from MOO satisfies the regulations in the code provision, the actual nonlinear behavior shows that the plastic deformation is concentrated in the link member of a certain story, resulting in the formation of a soft story, which violates the capacity design concept in the design code. To address this problem, another constraint based on the Eurocode was added to ensure that the maximum values of the shear overstrength factors of all links did not exceed 1.25 times the minimum values. When this constraint was added, it was observed that the resulting pareto front complied with both the design regulations and capacity design concept. Ratios of the link length to beam span ranged from 10% to 14%, which was within the category of shear links. The overall design is dominated by the constraint on the link's overstrength factor ratio. Design characteristics required by the design code, such as interstory drift and member strength ratios, were conservatively compared to the allowable values.

트러스 형태에 따른 스태거드트러스 골조시스템의 내진성능 평가

홍윤수,유은종,나창순,Hong, Yoon-Soo,Yu, Eun-Jong,Rha, Chang-Soon 한국전산구조공학회 2017 한국전산구조공학회논문집 Vol.30 No.5

본 연구의 목적은 트러스의 형태를 바꿔가며 엇갈린 트러스(STF) 시스템의 내진성능을 평가하는 것이다. 예제 구조물은 10층의 철골조 사무실 건물이며, 시스템별로 각각 프랫트러스, 하우트러스, 와렌트러스, 케이트러스와 비렌딜트러스를 적용하였다. 중력하중, 풍하중, 지진하중을 고려한 구조해석을 실시하여 부재에 높은 DCR을 만족하는 단면을 산정한 후 고유주기, 밑면전단력과 층간변위를 산출하였다. 그 후, 역량스펙트럼법을 통해 1.2배의 설계지진(DE)과 최대고려지진(MCE)에 대한 성능점을 산정하고, STF 시스템의 항복여부 및 소성힌지의 분포를 파악하여 구조기준에서 제시한 목표성능수준을 만족하는지 살펴보았다. 평가 결과, 모든 시스템이 해당 목표성능수준을 만족하였으며, 시스템의 경제성 및 효율성을 따져보았을 때, PR10이나 VR10이 가장 적합한 것으로 나타났다. The purpose of this study is to evaluate the seismic performance of Staggered Truss Frame(STF) system while changing a shape of truss. The model of this project is a office building of ten floors with Pratt, Howe, Warren, K and Vierendeel truss system applied on each model. Next step is to select the section of elements which satisfy the highest demand capacity ratio by structure design considering gravity load, earthquake load and wind load and then calculate natural period, base shear and story drifts. On the basis of these values, Capacity Spectrum Method(CSM) shows the plastic behavior of STF system such as performance point of Design Earthquake(DE) and Maximum Considered Earthquake(MCE), yield state, plastic hinge etc. to be compared with other truss systems. As a result, Vierendeel STF system especially was found to have the highest strength and stiffness to the corresponding earthquake and all the models for each truss shape fulfilled the target performance level.

혈액투석 환자의 소양증 양상과 관련된 인자 분석

홍윤수 ( Yoon Soo Hong ),이금희 ( Keum Hee Lee ),김귀경 ( Kwi Kyung Kim ),이주영 ( Joo Young Lee ),황은아 ( Eun Ah Hwang ),한승엽 ( Seung Yeup Han ),박성배 ( Sung Bae Park ),김현철 ( Hyun Chul Kim ) 대한신장학회 2008 춘계학술대회 초록집 Vol.28 No.1

혈액투석환자 중 소양증군과 비소양증군의 특성 비교연구

박정숙,홍윤수,이금희,김귀경,이혜란 기초간호학회 2009 Journal of korean biological nursing science Vol.11 No.1

생활수준의 향상과 현대의학의 발달로 노령 인구의 급격한 증가와 더불어 과거에 비해 만성 질환자의 빈도가 급성질환 에 비해 현저히 증가하고 있다. 일반적으로 사구체여과율이 50-60 mL/min 이하로 감소되었을 때 임상증상이 나타나며 15 mL/min 미만으로 감소하면 생명 유지를 위해 투석 또는 신장이식과 같은 신 대체요법이 필수적이다(Kim et al., 2006). 만성신부전 환자 수는 전 세계적으로 매년 증가하는 추세에 있으며, 국내의 경우도 최근 10여 년간 지속적으로 증가하였 으며 혈액투석을 받고 있는 환자 수는 2005년 27,246명에서 2006년 29,031명으로 7.5%의 증가율을 보이고 있다(The Korean Society of Nephrology, 2007). 신대체요법 중 가장 널리 사용되고 있는 혈액투석요법은

지역특성을 반영한 지진손실평가

김준형,홍윤수,유은종 한국지진공학회 2023 한국지진공학회논문집 Vol.27 No.6

When an earthquake occurs, the severity of damage is determined by natural factors such as the magnitude of the earthquake, the epicenter distance, soil properties, and type of the structures in the affected area, as well as the socio-economic factors such as the population, disaster prevention measures, and economic power of the community. This study evaluated the direct economic loss due to building damage and the community’s recovery ability. Building damage was estimated using fragility functions due to the design earthquake by the seismic design code. The usage of the building was determined from the information in the building registrar. Direct economic loss was evaluated using the standard unit price and estimated building damage. The standard unit price was obtained from the Korean Real Estate Board. The community’s recovery capacity was calculated using nine indicators selected from regional statistical data. After appropriate normalization and factor analysis, the recovery ability score was calculated through relative evaluation with neighboring cities.

트러스 형태에 따른 스태거드트러스 골조시스템의 구조특성에 관한 연구

나창순,홍윤수,유은종 한국전산구조공학회 2017 한국전산구조공학회논문집 Vol.30 No.3

This paper analyzed structural behaviors of the staggered truss system, typically used in low seismicity regions, resisting the lateral loads such as wind and seismic load. A comparative study of cost and efficiency was carried out by analysing and designing the 10- and 20-story buildings with various types of truss, including pratt, howe, warren, K-, and vierendeel, which may typically be used in staggered truss system. In design, column and truss members are selected in group, and the efficiency of the member design was judged by average demand capacity ratio of the all members in same group. And economic analysis of the system was investigated by the quantity of the structural members. As a result, staggered truss system with the pratt truss and warren truss showed the most economical and efficient performance for 10-story building, and 20-story building, respectively.

혈액투석 중 동영상을 이용한 운동요법이 혈액투석환자의 심리적 웰빙, 우울 및 혈액화학지표에 미치는 효과

안경순(Ahn, Kyung-soon),홍윤수(Hong, Yon-Soo),조영제(Cho, Young-Je),손명희(Son, Myung-Hee),신영희(Shin, Yeong Hee) 계명대학교 간호과학연구소 2015 계명간호과학 Vol.19 No.1

Purpose: This study investigated the effects of the exercise guided by video taped program during hemodialysis on psychological wellbeing, depression and blood chemicals of the patients with end stage renal failure. Method: This study used a nonequivalent control group pretest-posttest design. The experimental group (n=31) received 15-20 minutes of low-intensity exercise guided by video during hemodialysis, 3 times a week for 8 weeks, and usual care. The control group (n=31) received usual care only. The main outcome measures include Wellbeing Picture Scale, CES-D, and blood chemical indices. Results: After an 8-week intervention, significant improvements were noted in both Wellbeing Picture Scale scores (t=-2.09, p=.048) and CES-D scores (t=2.77, p=.009) and serum K level(t=-2.57, p=.016). Conclusion: A low-intensity exercise guided by video during hemodalysis is a complementary, safe, and effective clinical treatment modality in hemodialysis patients.

Delayed Perforation Occurring after Endoscopic Submucosal Dissection for Early Gastric Cancer

강수훈,이경호,이현우,박가은,홍윤수,민병훈 대한소화기내시경학회 2015 Clinical Endoscopy Vol.48 No.3

Delayed perforation is a very rare complication of endoscopic submucosal dissection (ESD), with a reported incidence of 0.1% to 0.45%. Few reports exist on the clinical features and outcomes of delayed perforation after ESD, and it is unclear whether the optimal management strategy is emergency surgery or endoscopic closure with conservative treatment. Here, we report two cases of delayed perforation occurring after ESD for early gastric cancer. In both cases, lesions were located in the antrum, and tumor depths were confined to the mucosal layer. Total procedure times for ESD were 25 and 45 minutes, respectively. Because delayed perforation may be associated with excessive thermal damage and necrosis of the muscle layer, treatment with emergency surgery should be used instead of conservative management in cases of delayed perforation after ESD.