• 제목/요약/키워드: small scale model

검색결과 1,205건 처리시간 0.027초

철근콘크리트 축소모형의 유사동적실험과 진동대 실험을 위한 상사법칙 연구 (A Study on Similitude Law for Pseudodynamic Tests and Shaking Table Tests on Small-scale R/C Models)

  • 양희관;서주원;조남소;장승필
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2006년도 학술발표회 논문집
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    • pp.545-552
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    • 2006
  • Small-scale models have been frequently used for seismic performance tests because of limited testing facilities and economic reasons. However, there are not also enough studies on similitude law for analogizing prototype structures accurately with small-scale models, although conventional similitude law based on geometry similitude is not well consistent in their inelastic seismic behaviors. When fabricating prototype and small-scale model of reinforced concrete structures by using the same material, added mass is demanded from a volumetric change and scale factor could be limited due to aggregate size. Therefore, it is desirable to use different materials for small-scale model. In our recent study, a modified similitude law was derived depending on geometric scale factor, equivalent modulus ratio and ultimate strain ratio. And quasi-static and pseudo-dynamic tests on the specimens are carried out using constant and variable modulus ratios, and correlation between prototype and small-scale model is investigated based on their test results. In this study, tests on scaled model of different concrete compressive strength aye carried out. In shaking table tests, added mass can not be varied. Thus, constant added mass on expected maximum displacement was applied and the validity was verified in shaking table tests. And shaking table tests on non-artificial mass model is carried out to settle a limitation of acceleration and the validity was verified in shanking table tests.

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Assessment of Dispersion Coefficients and Downward Positions of Water Spray for Small-Scale Release of Chlorine Gas

  • Jang, Seo-Il;Kim, Youngran;Yu, Wooyun;Shin, Dongil;Park, Kyoshik;Kim, Tae-Ok
    • 한국가스학회지
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    • 제19권1호
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    • pp.51-56
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    • 2015
  • To assess downward positions of water spray for the small-scale release of chlorine gas, dispersion coefficients for the Gaussian dispersion model were validated at the small-scale release experiment. And the downwind distances of water spray were assessed with the simulated results. As results, the Gaussian plume model using the Briggs' dispersion coefficient well estimated the dispersed characteristics for small-scale release of chlorine gas. The best adequate downwind position of water spray is the position of the maximum concentration of chlorine at the ground level. And the adequate vertical and horizontal dimensions of water spray consider the maximum width and height of cloud.

FRP복합체로 보강된 실물모형 RC보의 보강재 강성에 따른 휨 보강성능 (Flexural Performance of Full-scale RC Beams Strengthened with Different Amount of FRP Composite)

  • 최기선;유영찬;김긍환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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    • pp.125-128
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    • 2006
  • Many research have been carried out concerned with the flexural performance of FRP composite in a various ways. Most of them, however, have used a small-scale specimen, so haven't been fully verified by full-scale model test. In this study, a full-scale RC beam model test for flexural strengthening with CFRP composites has been performed in order to verify test results obtained through a series of small-scale model test with respect to FRP stiffness affecting strengthening performance in the previous studies. A total of 4 specimens have been manufactured including control beam. The specimens strengthened with CFRP composites consist of 3 different CFRP stiffness with 2 types of CFRP composite. Consequently, the purpose of this study is to estimate influence of the size effect of specimens and FRP stiffness on the flexural performance. As a result, the effective strain of FRP composite is inversely proportional to FRP stiffness and ensures the same performance with small-scale model test.

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The use of small scale model testing to compare connection methods of steel purlins

  • Urquhart, Stephen M.;Kavanagh, Kenneth T.
    • Structural Engineering and Mechanics
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    • 제6권5호
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    • pp.571-582
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    • 1998
  • Testing of steel roof purlins is usually performed on full scale models in large vacuum test rigs. To undertake a comparison between web cleat connected purlins and flange bolted purlins a series of tests were performed on a 1:4 small scale model vacuum test rig. Various modelling issues need to be addressed to ensure reasonable comparison with actual constructed roof framing methods but still be suitable for an economical comparison between the connection methods. Model test results were supported by, and found to be in reasonable agreement with, deflection predictions from computer models based on finite element methods. This paper discusses the testing methods adopted and the value of small scale model testing programs as a means of obtaining comparisons between framing options.

Influence of shear preload on wave propagation in small-scale plates with nanofibers

  • Farajpour, M.R.;Shahidi, A.R.;Farajpour, A.
    • Structural Engineering and Mechanics
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    • 제70권4호
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    • pp.407-420
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    • 2019
  • In the present work, an attempt is made to explore the effects of shear in-plane preload on the wave propagation response of small-scale plates containing nanofibers. The small-scale system is assumed to be embedded in an elastic matrix. The nonlocal elasticity is utilized in order to develop a size-dependent model of plates. The proposed plate model is able to describe both nanofiber effects and the influences of being at small-scales on the wave propagation response. The size-dependent differential equations are derived for motions along all directions. The size-dependent coupled equations are solved analytically to obtain the phase and group velocities of the small-scale plate under a shear in-plane preload. The effects of this shear preload in conjunction with nanofiber and size effects as well as the influences of the elastic matrix on the wave propagation response are analyzed in detail.

A Study on Korean Sentiment Analysis Rate Using Neural Network and Ensemble Combination

  • Sim, YuJeong;Moon, Seok-Jae;Lee, Jong-Youg
    • International Journal of Advanced Culture Technology
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    • 제9권4호
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    • pp.268-273
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    • 2021
  • In this paper, we propose a sentiment analysis model that improves performance on small-scale data. A sentiment analysis model for small-scale data is proposed and verified through experiments. To this end, we propose Bagging-Bi-GRU, which combines Bi-GRU, which learns GRU, which is a variant of LSTM (Long Short-Term Memory) with excellent performance on sequential data, in both directions and the bagging technique, which is one of the ensembles learning methods. In order to verify the performance of the proposed model, it is applied to small-scale data and large-scale data. And by comparing and analyzing it with the existing machine learning algorithm, Bi-GRU, it shows that the performance of the proposed model is improved not only for small data but also for large data.

소형가스루프 시험조건에서 소형 공정열교환기 시제품의 고온구조해석 (High-Temperature Structural Analysis on the Small-Scale PHE Prototype under the Test Condition of Small-Scale Gas Loop)

  • 송기남;홍성덕;박홍윤
    • 한국압력기기공학회 논문집
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    • 제8권1호
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    • pp.1-7
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    • 2012
  • A PHE (Process Heat Exchanger) is a key component required to transfer heat energy of $950^{\circ}C$ generated in a VHTR (Very High Temperature Reactor) to the chemical reaction that yields a large quantity of hydrogen. A small-scale PHE prototype made of Hastelloy-X is being tested in a small-scale gas loop at Korea Atomic Energy Research Institute. In order to properly evaluate the high-temperature structural integrity of the small-scale PHE prototype, it is very important to impose a proper constraint condition on its structural analysis model. For this effort, we tried to impose several constraint conditions on the structural analysis model and consequently fixed a proper and effective displacement constraints.

소형 탈선 시뮬레이터 축소모델 동특성 해석에 관한 연구 (A study on the Dynamic analysis of 1/5 scale derailment simulator model)

  • 이세용;엄범규;강부병;이희성
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.337-342
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    • 2011
  • A roller rig has been widely used in the study about dynamic stability and railway safety. However, the cost for constructing the roller rig and the difficulty in adjusting the design parameters for vehicle systems lead to the development of a small scale simulator which is cheaper than the large scale test systems and easy to control the parameters affecting dynamic characteristics of the railway vehicle. For the operation of the small scale test system called a small scale simulator, it is required to investigate the performance and characteristics of the system. This could be achieved by a comparative study between an analysis and an experiment. This paper presented the analytical model which could be used for verifying of the test results and understanding of the physical behavior of the dynamic system comprising the small scale bogie and the simulator.

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Small-World 망과 Scale-Free 망을 위한 일반적인 망 생성 방법 (Generalized Network Generation Method for Small-World Network and Scale-Free Network)

  • 이강원;이재훈;최혜진
    • 한국통신학회논문지
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    • 제41권7호
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    • pp.754-764
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    • 2016
  • 최근 들어 다양한 SNS(Social Network Service)에 대한 이해와 분석을 위해 가장 중요한 두 종류의 망인 small-world와 scale-free망에 대한 많은 연구가 수행되고 있다. 본 연구에서는 두 개의 입력 파라미터를 적절히 조정함으로서 small-world 망, scale-free 망 혹은 두 개의 성질을 동시에 모두 갖는 망을 생성 할 수 있는 보다 일반화된 망 생성 방법을 제안하였다. 두개의 입력 파라미터중 하나는 small-world 성질을 나태내주는 파라미터고 다른 하나는 scale-free와 small-world 성질 모두를 나타내주는 파라미터다. Small-world와 scale-free를 나타내주는 망의 성질로 군집계수, 평균 최단거리 그리고 power-law 상수를 이용하였다. 본 연구에서 제안한 방법을 사용하면 small-world 망과 scale-free 망의 성질과 관계에 대한 보다 명확한 이해를 할 수 있다. 다양한 여러 예제들을 통하여 두 개의 입력 파라미터들이 군집계수, 평균 최단거리 그리고 power-law 상수에 미치는 영향을 검증하였다. 이를 통해 어떠한 입력 파라미터들의 조합이 small-world 망, scale-free 망 혹은 두 개의 성질을 모두 갖는 망을 생성 할 수 있는지를 조사하였다.

스크럼을 활용한 소규모 소프트웨어 개발 기반의 소프트웨어 프로세스 인증 모델 (A Software Process Certification Model of Small sized Software Development Using Scrum)

  • 송인오;류성열;이성은
    • 한국컴퓨터정보학회논문지
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    • 제16권4호
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    • pp.215-223
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    • 2011
  • 소규모의 프로젝트에 소프트웨어 프로세스 인증 모델을 적용하기에는 참여인력 구성, 프로젝트 관리 및 품질 보증 등을 위한 활동과 문서 작성에 많은 어려움이 있다. 본 연구는 애자일 방법인 스크럼과 정보통신산업진흥원에서 제시한 SP인증 모델의 필수요소들을 결합하여 소규모 소프트웨어 개발에 적합한 소프트웨어 프로세스 인증 모델을 제시한다. 제시한 모델은 SP인증 획득에 필요한 최소한의 수행활동, 그리고 산출물을 정의하였다. 제시 모델은 16개의 프로세스와 58개의 수행활동으로 구성되며 39개의 산출물이 작성된다. 제시한 모델을 중소표준프로세스와 비교한 결과 수행활동은 38%, 작성문서는 20% 감소하여 소규모 프로젝트에서 부담이 경감되었음을 확인하였다. 그리고 제시 모델의 활용 가능성을 검증하기 위하여 2개의 소규모 프로젝트에 적용한 결과, 스크럼 프로세스만으로 진행한 프로젝트와 비교하여 추가인원 없이 체계적인 관리를 할 수 있었고, 정해진 기간 안에 프로젝트를 완료하였으며 SP인증 2등급 획득하여 그 유용성을 검증하였다.