탄소섬유쉬트의 보강길이에 따른 R/C보의 휨 거동

신성우,안종문,이광수,반병렬,염성기,Shin, Sung Woo,Ahn, Jong Mun,Lee, Kwang Soo,Ban, Byung Lyul,Yeom, Sung Ki 한국구조물진단유지관리공학회 1998 한국구조물진단유지관리공학회 논문집 Vol.2 No.1

It is demanded to obtain the design data for bond length of the strengthening carbon fiber sheets. An objectives of this study is to provide preliminary data of rational strengthening design method which is adequate to current domestic status. The present experimental study was performed to evaluate flexural strengthening effects of steel reinforced concrete beams strengthened with carbon fiber sheets. Following conclusions can be extracted. It is revealed that the maximum load carrying capacity is increased up to 9% when the reinforced concrete beams were strengthened with 1-ply of carbon fiber sheet which is half-width of beam. The performance of reinforced concrete sections were improved due to the strengthening carbon fiber sheets on the tensile side of beams. It is believed that the strengthening length of carbon fiber sheets must be provided as (0.5l+3d) to secure the ductile capacity of above three for the flexural strengthening of reinforced concrete beams.

일최대풍속 데이터를 이용한 구조설계용 기본풍속 산정

신성우,권구안,이종원,Shin, Sung-Woo,Kwon, Koo-Ahn,Lee, Jong-Won 대한건축학회 2011 대한건축학회논문집 Vol.27 No.7

The regions with newly organized meteorological observatory do not have sufficient amount of wind speed data for the extremal analysis, so it is difficult to estimate the Basic Wind Speed using the extremal analysis. Therefore, it is necessary to find a way how to estimate the Basic Wind Speed using the extremal analysis with a few amount of data. This study focuses on the estimation of the Bagic Wind Speed using the daily maximum wind speed data by utilizing the Davenport distribution based Bi-Weibull distribution.

차원 축소된 표면파 투과 함수와 인공신경망을 이용한 콘크리트 구조물의 균열 깊이 평가 기법

신성우,윤정방,Shin, Sung-Woo,Yun, Chung-Bang 한국전산구조공학회 2007 한국전산구조공학회논문집 Vol.20 No.3

현장에서 콘크리트 구조물의 균열 깊이를 추정하기 위한 자기 보정 표면파 투과 측정과 측정된 투과 함수의 차단주파수를 이용하는 기존의 방법은 측정 조건에 따른 투과 함수의 변동성이 매우 커서 실제로 적용하기가 어려운 단점이 있다. 본 연구에서는 차단주파수와 같이 특정 주파수를 선정하여 균열 깊이를 추정하는 방법 대신에 측정된 자기 보정 표면파 투과 함수 자체를 균열 깊이 추정에 이용하는 방법을 제안하고자 한다. 이를 위하여 다양한 균열 깊이에서 측정된 자기 보정 표면파 투과 함수를 주성분 분석법을 이용하여 차원을 축소한 후, 축소된 투과 함수를 인공신경망의 입력으로 사용하여 이로부터 균열 깊이를 추정하는 방법을 제시하였다. 한편, 제안된 방법의 유효성을 판단하기 위하여 서로 다른 균열 깊이를 가진 5개의 실험체에 대하여 실험적인 연구를 수행하였으며, 실험 결과 제안된 방법이 콘크리트 구조물이 균열 질이 평가에 매우 유효한 방법임을 알 수 있었다. Determination of crack depth in filed using the self-calibrating surface wane transmission measurement and the cutting frequency in the transmission function (TRF) is very difficult due to variations of the measurement conditions. In this study, it is proposed to use the measured full TRF as a feature for crack depth assessment. A Principal component analysis (PCA) is employed to generate a basis of the measured TRFs for various crack cases. The measured TRFs are represented by their projections onto the most significant principal components. Then artificial neural networks (NNs) using the PCA-compressed TRFs is applied to assess the crack in concrete. Experimental study is carried out for five different crack cases to investigate the effectiveness of the proposed method. Results reveal that the proposed method can be effectively used for the crack depth assessment of concrete structures.

고강도 경량 콘크리트의 부착특성

신성우,이광수,최명신,김현식,Shin, Sung-Woo,Lee, Kwang-Soo,Choi, Myung-Shin,Kim, Hyun-Sik 한국콘크리트학회 1999 콘크리트학회지 Vol.11 No.2

최근들어 그 필요성이 증대되고 있는 경량 콘크리트의 경우, 부착강도의 저하를 고려하여 ACI 규준에서는 부착길이 보정계수를 도입하여 안전율을 높이고 있으나, 경량 콘크리트가 고강도화됨에 따라 어느 정도 부착강도의 증징이 있을 것으로 판단된다. 따라서 ACI 규준에서 정하고 있는 경량 콘크리트에 대한 부착길이 보정계수 ${\lambda}$=1.3을 고강도 경량 콘크리트에 적용할 경우 그 적정성 여부에 대한 검토가 필요하다. 본 연구에서는 고강도 경량 콘크리트의 부착특성을 알아보기 위하여 콘크리트 압축강도, 피복두께, 철근직경, 부착길이 등을 변수로 하여 Pull-out 실험을 실시하였다. 실험결과 부착응력은 콘크리트 압축강도 제곱근과 피복두께가 증가함에 따라 증가하였고, 철근직경과 부칙길이가 증가함에 따라 감소하였으며, 파괴양상은 피복두께에 따라 쪼개짐 파괴와 뽑힘 파괴를 나타내었다. 고강도 경량 콘크리트의 부착응력을 보통중량 콘크리트보다는 큰 값을 나타낸다. 따라서 ACI 규준에서 정하고 있는 경량 콘크리트 부착길이 보정계수를 고강도 경량 콘크리트에 적용할 경우 경량 콘크리트의 고강도화에 따른 부착응력 상승효과를 고려하여 하향조정하여야 할 것으로 판단된다. 또한 피복두께 2.5$d_b$ 이상일 경우 적용하는 피복두께 보정계수 0.8은 고강도 경량 콘크리트에도 그대로 적용할 수 있음을 알 수 있다. Recently, it is increased the use of High-Strength Light-Weight Concrete(HLC) in the high-rise buildings and mega-structures. But there are a few research on the bond behavior of HLC, so it need to study about that. The present study was performed to investigate the bond characteristics of HLC. Major test variables include concrete compressive strength(f'c), concrete cover(c), bond length (${\ell}_{db}$), and bar diameter($d_b$). Test results indicate that the bond stress of HLC is increased with the increment of $\sqrt{f'_c}$ and concrete cover, bond stress is decreased with increment of bond length and bar diameter. And the final failure mode such as splitting or pullout failure is significantly affected by the concrete cover to bar diameter ratios(C/$d_b$). Test results were compared with ACI code and other proposed equations. The bond stress of HLC is higher than that of normal-strength normal-weight concrete, but lower than that of high-strength normal-weight concrte. Considering the present test results, modification factor(${\lambda}$= 1.3) of bond length in ACI 318-95 code for light-weight concrete is may have to be reviewed to apply to HLC.

고강도 경량 철근콘크리트보의 전단보강 효과

신성우,이광수,안종문,최명신,Shin, Sung-Woo,Lee, Kwang-Soo,Ahn, Jong-Mun,Choi, Myung-Shin 한국콘크리트학회 1999 콘크리트학회지 Vol.11 No.1

본 연구에서는 전단보강비율에 따른 고강도경량 철근콘크리트보의 전단거동을 규명하기 위하여 15개의 실험체를 제작하여 실험하였다. 실험변수는 전단스팬비(a/d=2.5, 3.5, 4.5)와 전단보강근비($0{\sim}1.0_{ACI}{\rho}_v$)이고 큰크리트의 압축강도 (439kg/$cm^2$)와 주철근비(0.02023)는 일정하게 하였다. 실험결과, ACI 규준식은 고강도경량 철근콘크리트보에서 큰크리트의 전단내력은 과소평가하는 반면 전단보강근의 전단내격은 과대평가하는 것으로 나타났다. 큰크리트의 전단강도($V_{cr}$)식에서 경량콘크리트에 대한 추가적인 전단강도저감계수 ${\lambda}$=0.85는 경량콘크리트의 고강도화에 따라서 다소 상향조정하여 사용할 필요가 있는 것으로 보인다. 또한, 전단보강근의 전단강도는 보통중량콘크리트보와 같이 전단보강비율에 직선적으로 비례하는 것이 아니라 그 제곱근에 비례하는 경향을 보였으며, 따라서 고강도경량 철근콘크리트보에서 전단보강근의 유효성(전단보강의 효과)은 보통중량콘크리트에 비해 떨어진다고 볼 수 있다. In this study, fifteen reinforced high-strength lightweight concrete(HLC)beams were tested to investigate shear behavior of specimens according to shear reinforcement ratio. Test variables are shear span to effective depth ratio(a/d=2.5, 3.5, 4.5) and shear reinforcement ratio(0~1.0${\rho}_{v,ACI}$). Concrete compressive strength and tensile steel reinforcement ratio are constantly 439kg/$cm^2$ and 0.0203, respectively. Test results for the HLC beams showed that ACI code equation underestimates the shear strength of concrete($V_c$), and overestimates the shear strength of shear reinforcements($V_s$). It is revealed that the effectivenesses of shear reinforcements of reinforced HLC beams are lower than those of normal weight concrete beams. Then, the shear strengths of shear reinforcements are increased in proportion not to first degree of shear reinforcement ration but to square root of them.

주식 투자 영역에서의 한글 자연어 처리 시스템의 설계 및 구현

신성우(Sungwoo Shin),이일병(Yillbyung Lee) 한국정보과학회 언어공학연구회 1990 한국정보과학회 언어공학연구회 학술발표 논문집 Vol.1990 No.11

신경회로망을 적용한 기능경사 내열 복합재의 최적설계

신성우(S. W. Shin),박형종(H. J. Park),조진래(J. R. Cho) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.8

For the high temperature engineering applications, materials used are required to possess superior thermo-mechanical performances, such as high temperature strength and creep resistance, especially fracture toughness and thermal shock resistance. So, laminated composites have been used for several decades as a heat-resisting material. But, there exists one inevitable disadvantage in classical laminate composites. To resolve this problem, a notion of functionally graded materials(FGM) was introduced. In FGMs, a material composition varies continuously from one end to the other of graded layer. In oder to find suitable volume fraction distribution in the graded layer for relaxing thermal stress, we apply optimization technique and neural network algorithm. The purpose of the use of neural network is to minimize the total CPU time by reducing the number of finite element analysis. As well, we confirmed that the neural network leads to reliable approximation of the objective function.

타이어 접지압 분포특성 규명을 위한 신경회로망 적용연구

신성우(S. W. Shin),정현성(H. S. Jeong),조진래(J. R. Cho),김남전(N. J. Kim),김기운(K. W. Kim) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.4

Tire is a very important part of automobile because it supports entire automobile weight. As well, it characterizes major tire and automobile performances. Here, we intend to analyse contact pressure characteristics of tire by using neural algorithm. The tire analysis includes very difficult issues such as contact treatment, nonlinear material behavior and 3D analysis for contact pressure, and which requires considerably long CPU time. In order to minimize the numerical analysis cost, we employ a neural network for learning the tire contact pressure behavior.

자연진동을 이용한 건물의 시스템 판별

신성우 ( Shin Sung-woo ),유석형 ( Yoo Suk-hyeong ) 한국구조물진단유지관리공학회 2006 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.10 No.1

The measurement chain to collect accelerations at selected points in large civil engineering structures due to natural vibration has been established, and a large scale test on twenty four story buildings has been performed Measurement system consists of force-balanced type sensors with high dynamic range, DAQ with several input ranges and USB interface, and a control module capable of varying the sampling frequency without limit, for instance from 1Hz to 1kHz. From measured acceleration records, useful information such as natural frequencies, damping ratios and mode shapes were extracted from the analysis chain consisting of signal processing, peak-picking and sto-chastic subspace identification modules. Comparing with the predicted results by FEM, the present hybrid evaluation system is acceptable when considering the fact that the analysis only relies on the output without measuring the input.

서포트 벡터 머신을 이용한 건설업 안전보건관리비 예측 모델

신성우 ( Sung Woo Shin ) 한국안전학회(구 한국산업안전학회) 2017 한국안전학회지 Vol.32 No.1

The aim of this study is to develop construction safety and health management cost prediction model using support vector machine (SVM). To this end, theoretical concept of SVM is investigated to formulate the cost prediction model. Input and output variables have been selected by analyzing the balancing accounts for the completed construction project. In order to train and validate the proposed prediction model, 150 data sets have been gathered from field. Effects of SVM parameters on prediction accuracy are analyzed and from which the optimal parameter values have been determined. The prediction performance tests are conducted to confirm the applicability of the proposed model. Based on the results, it is concluded that the proposed SVM model can effectively be used to predict the construction safety and health management cost.