• 한국지진공학회논문집
• /
• 제24권1호
• /
• pp.29-37
• /
• 2020

This study is to investigate the effect of a retrofitted reinforced concrete frame with non-seismic details strengthened by embedded steel moment frames with an indirect joint, which mitigates the problems of the direct joint method. First, full-scale experiments were conducted to confirm the structural behavior of a 2-story reinforced concrete frame with non-seismic details and strengthened by a steel moment frame with an indirect joint. The reinforced concrete frame with non-seismic details showed a maximum strength of 185 kN at an overall drift ratio of 1.75%. The flexural-shear failure of columns was governed, and shear cracks were concentrated at the beam-column joints. The reinforced concrete frame strengthened by the embedded steel moment frames achieved a maximum strength of 701 kN at an overall drift ratio of 1.5% so that the maximum strength was about 3.8 times that of the specimen with non-seismic details. The failure pattern of the retrofitted specimen was the loss of bond strength between the concrete and the rebars of the columns caused by a prying action of the bottom indirect joint because of lateral force. Furthermore, methods are proposed for calculation of the specified strength of the reinforced concrete frame with non-seismic details and strengthened by the steel moment frame with the indirect joint.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
• /
• pp.11-14
• /
• 2000

We present an image retrieval method that improves retrieval rate by using the fusion of histogram and wavelet moment features. The key idea is that images similar to a query image are selected in DB by using the wavelet moment features. Then the result images are retrieved from the selected images by using histogram method. In order to evaluate the performance of the proposed method, we use Brodatz texture database, MPEG-7 T1 database and Corel Draw photo. Experimental result shows that the proposed method is better than each of histogram method and wavelet moment method.

• 한국자동차공학회논문집
• /
• 제6권1호
• /
• pp.222-233
• /
• 1998

A 4-point pure bending res machine is developed the evaluate the pure vending moment-rotation properties of the thin-walled tubes without imposing shear and tensile forces. The moment-rotation properties of the thin-walled tubes are measured up to and beyond collapse with the pure bending test machine. The test results are compared with those of finite element analyses and existing analytical solution.

• Ecology and Resilient Infrastructure
• /
• 제7권4호
• /
• pp.308-319
• /
• 2020

본 논문은 경북 영천시 서문보에 최근 건설된 다기능 어도의 현장 적용성을 검토하기 위해 해석 변수를 R/C Slab (S1), R/C+S/C Slab (S2) 및 지하이동통로 규격 (가로 × 세로)을 1.4 × 0.2 m, 1.4 × 0.3 m, 1.4 × 0.6 m와 유속 0.8 m/s, 1.2 m/s, 1.6 m/s 으로 구분하여 해석한 결과 서문보 설계식 안전성을 평가하였다. 서문보의 설계식 보다 R/C+S/C Slab타입이 지하이동통로 출구부는 휨모멘트와 최대응력은 각각 16 - 33%, 24 - 32%, 측벽은 각각 17 - 33%, 20 - 36%, 상부슬래브인 경우도 19 - 33%, 9 - 28% 적게 나타났다. 따라서 최대응력과 휨모멘트가 R/C+S/C Slab 타입이 구조 안전성이 확보되는 것으로 나타났다. 따라서 지하통로는 휨모멘트와 최대 응력이 각각 14%, 18%, 측벽은 17%, 15% 상부슬래브는 16%, 11%의 보완이 요구되는 것으로 판단된다. 이러한 결과는 지하이동통로 규격이 서문보 규격과 동일한 1.4 × 0.3 m 일 때가 1.4 × 0.2 m, 1.4 × 0.6 m보다 안전성이 가장 유리한 것으로 확인되었다. 또한 해석 및 분석 결과를 근거로 서문보 규모의 다기능 어도 적용 시 기본 자료로 활용이 기대된다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제18권6호
• /
• pp.50-59
• /
• 2014

본 논문에서는 경북 구미시 봉곡천에 최근 건설된 다기능어도를 대상으로 SAP2000으로 구조 해석하기 위한 변수를 R/C Slab, R/C+S/C Slab 및 지하이동통로 규격(가로${\times}$세로)을 $1m{\times}0.2m$, $1m{\times}0.4m$, $1m{\times}0.6m$와 유속 0.8m/s, 1.2m/s, 1.6m/s으로 구분하여 해석한 결과와 봉곡천 설계식을 비교하여 안정성을 검토하였다. 봉곡천의 설계식 보다 R/C+S/C Slab 타입이 지하이동통로 출구부는 휨모멘트와 최대응력은 각각 28~54%, 26~50%, 측벽은 24~47%, 17~31%, 상부슬래브인 경우도 10~27%, 4~20% 적게 나타났다. 따라서 최대응력과 휨모멘트가 R/C+S/C Slab 타입이 구조 안정성이 확보되는 것으로 나타났기 때문에 지하통로는 휨모멘트와 최대 응력이 27%, 25%, 측벽은 24%, 15% 상부슬래브는 14%, 10%의 보완이 요구되는 것으로 판단된다. 이러한 결과는 지하이동통로 규격이 봉곡천 규격과 동일한 $1m{\times}0.4m$일 때가 $1m{\times}0.2m$, $1m{\times}0.6m$ 보다 안정성이 가장 유리한 것으로 확인되었다. 또한 해석 및 분석 결과를 근거로 다기능어도 시공 시 기본 자료로 활용이 기대된다.

• 한국정보통신학회논문지
• /
• 제17권12호
• /
• pp.3001-3008
• /
• 2013

심음도(PCG, Phonocardiogram) 분석을 이용하여 심장의 판막과 관련된 질환을 진단하기 위해서는 먼저 심음 분할을 위해 심음의 주성분인 S1과 S2를 정확하게 찾아야 한다. 본 논문에서는 심음포락선의 모멘트 특성을 분석하고 이를 심음 분할에 적용하였다. 기존의 2차 모멘트를 이용한 심음 분할의 문제점을 분석하고, 심잡음이 있더라도 심음 주성분의 검출이 용이한 3차 모멘트에 기반한 방법을 제안하였다. 심음포락선은 심음 신호의 단구간 에너지를 이용하였으며, 3차 모멘트 궤적의 기울기 정보를 이용하여 심음 주성분을 검출하고 지속시간을 게이팅(gating) 하였다. 다양한 심잡음이 포함된 심음 신호에 대한 실험을 통해 제안한 방법이 기존의 2차 모멘트 기법보다 심잡음의 영향을 적게 받고 심음 주성분의 구간을 정확하게 검출 할 수 있음을 보였다.

• Nuclear Engineering and Technology
• /
• 제29권4호
• /
• pp.310-319
• /
• 1997

A finite element analysis of a trunnion pipe anchor is presented. The structure is analyzed for the case of internal pressure and moment loadings. The stress results are categorized into the average (membrane) stress, the linearly varying (bending) stress and the peak stress through the thickness. The resulting stresses are interpreted per Section III of the ASME Boiler and Pressure Vessel Code from which the Primary(B$_1$), Secondary(C$_1$) and Peak(K$_1$) stress indices for pressure, the Primary (B$_2$), Secondary(C$_2$) and Peak(K$_2$) stress indices for moment are developed. Based on the comparison between stress value by stress indices derived in this paper and stress value represented by the ASME Code Case N-391-1, the empirical equations for stress indices are effectively used in the piping stress analysis. Therefore, the use of empirical equations can simplify the procedure of evaluating the local stress in the piping design stage.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2003년도 추계 학술발표회논문집
• /
• pp.205-212
• /
• 2003

To evaluate the seismic performance of multistory building structures use an equivalent SDOF model. This paper presents a method of converting a MDOF system into an equivalent SDOF model. The principal objective of this investigation is to evaluate appropriateness of converting method through perform nonlinear time history analysis of a multistory building structures and an equivalent SDOF model. The hysteresis rules to be used an equivalent SDOF model is obtained from the pushover analysis. The conclusion of this study is following; A method of converting a MDOF system into an equivalent SDOF model through the nonlinear time history response analysis is valid. The representative lateral displacement of a moment resisting reinforced concrete frames is close to the height of the first modal participation vector $_1$$\beta$｛$_1$u｝=1. It can be found that the hysteresis rule of an equivalent SDOF model have influence on the time history response. Therefore, it is necessary for selecting hysteresis rules to consider hysteresis characteristics of a moment resisting reinforced concrete frames.

• Bulletin of the Korean Chemical Society
• /
• 제6권1호
• /
• pp.3-7
• /
• 1985

The general formulas for SCF atomic orbitals |5s > and |6p > have been derived separately by expressing the spherical harmonics part in terms of the coordinate($r_1,\;$r_2$) of the reference point, and by translating the exponential part, $r^4\;exp\;(-{\beta}r)$), in terms of $r_1,\;and\;r_2$ and the modified Bessel functions. Master formulas for overlap and dipole moment matrix elements are derived. The computed values of overlap and dipole moment matrix elements for hypothetical NO molecule are exactly in agreement with those for the previous methods.

• 대한수학회논문집
• /
• 제12권2호
• /
• pp.393-401
• /
• 1997

Let $A_1,A_2,\cdots,A_m$ and $B_1,B_2,\cdots,B_n$ be two sequences of events on a given probability space. Let $X_m$ and $Y_n$, respectively, be the number of those $A_i$ and $B_j$, which occur we establish new upper and lower bounds on the probability $P(X=r, Y=t)$ which improve upper bounds and classical lower bounds in terms of the bivariate binomial moment $S_{r,t},S_{r+1,t},S_{r,t+1}$ and $S_{r+1,t+1}$.