• 제목/요약/키워드: Time Dependent

검색결과 6,943건 처리시간 0.036초

Long-term flexural cracking control of reinforced self-compacting concrete one way slabs with and without fibres

  • Aslani, Farhad;Nejadi, Shami;Samali, Bijan
    • Computers and Concrete
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    • 제14권4호
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    • pp.419-444
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    • 2014
  • In this study experimental result of a total of eight SCC and FRSCC slabs with the same cross-section were monitored for up to 240 days to measure the time-dependent development of cracking and deformations under service loads are presented. For this purpose, four SCC mixes are considered in the test program. This study aimed to compare SCC and FRSCC experimental results with conventional concrete experimental results. The steel strains within the high moment regions, the concrete surface strains at the tensile steel level, deflection at the mid-span, crack widths and crack spacing were recorded throughout the testing period. Experimental results show that hybrid fibre reinforced SCC slabs demonstrated minimum instantaneous and time-dependent crack widths and steel fibre reinforced SCC slabs presented minimum final deflection.

Extradosed PSC Box 교의 시공단계해석 (Construction Stage Analysis of Extradosed PSC Box Bridges)

  • 윤군진;이완수;이종신;김성찬
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.347-354
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    • 2001
  • Extradosed PSC Box bridges, newly emerging type of structures in construction market, have a characteristic in that external tendons are used for strengthening PSC Box girder like stay cables in cable stayed bridges. In this study, a series of constructions stage analysis procedure, including initial shape analysis, backward analysis and forward analysis, have been performed in order to investigate long-term behavior of extradosed PSC box bridges, using PCCAP-a computer program for time-dependent stage analysis of PSC cable stayed bridges. CEB-FIP 1978 model was used for the consideration of time-dependent effect of concrete material. Showing the validity of the analysis results with RM SPACE FRAME, it has been confirmd that time-dependent effects become less consequential as the stiffness of girder becomes larger.

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준비시간(準備時間)이 종속인 다단계(多段階) 생산(生産) 시스템의 집단일정계획(集団日程計劃) (Group Scheduling Problem in Multi - Stage Manufacturing Systems with Dependent Setup time)

  • 노인규;남희열
    • 대한산업공학회지
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    • 제12권2호
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    • pp.33-44
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    • 1986
  • This research is concerned with group scheduling problems in multi-stage manufacturing system with dependent setup time. The objective of the research is to develop and evaluate a heuristic algorithm for determining group sequence and job sequence within each group to minimize total tardiness in multi-stage manufacturing systems with sequence dependent group setup time. The group scheduling heuristic algorithm is developed and evaluated by comparisons with twenty-seven problems with the known optimum solutions and 144,000 random schedules of a large variety problems. The results indicate that the proposed heuristic algorithm gets the same optimum solutions for the problems and also provides the good solutions in comparison with the random schedules of the large variety problems. A numerical example is given to illustrate the heuristic algorithm.

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시간종속적 하이퍼미디어 시스템을 위한 SGML DTD의 설계 (Design of SGML DTD for Time-dependent Hypermedia Documents)

  • 김호진;이수진;최윤철
    • 한국정보처리학회논문지
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    • 제5권10호
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    • pp.2479-2497
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    • 1998
  • 하이퍼미디어시스템을 모델링하기 위해 제공되는 기존의 표준 모델들이나 SGML을 이용하여 설계된 하이퍼미디어 시스템들은 저마다 서로 다른 정보기술 및 저장 방법론을 제시하고 있어 이질적인 시스템간의 문서 교환이나 프리젠테이션을 어렵게 만들고 있다. 그리고 사용자 인터랙션의 처리나 시간종속적 멀티미디어 객체(time-dependent multimedia object)들의 표현에 있어서도 많은 제한점들을 가진다. 본 논문에서는 시간종속적 멀티미디어 객체들을 효율적으로 표현할 수 있고 사용자의 인터랙션에 따라 멀티미디어 객체들을 서로 다른 정보 영역으로 링크시키며 시간종속적 링크를 제공해 주는 시간종속적 하이퍼미디어 시스템(Time-dependent Hypermedia System)을 모델링하고, 그러한 하이퍼미디어 시스템을 기술하기 위한 SGML 문서타입 정의부(Document Type Definition : DTD)를 설계한다. DTD의 설계에 있어서는 멀티미디어 객체들의 동기화를 위한 스케줄링 메커니즘과 다양한 노드 형태의 기술에 중점을 두고, 사용자들에게 구조 및 개념 파악의 용이성을 제공하기 위해 모듈 개념을 적용하였다.

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PSC 교량용 설계강도 60MPa 이상 고강도 콘크리트의 실용화를 위한 시간의존적 변형 및 내구성에 관한 연구 (Time-Dependent Deformation and Durability of High-Strength Concrete over 60MPa for PSC Bridges)

  • 양준모;이주하;정해문;안태송;윤영수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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    • pp.5-8
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    • 2006
  • In this study, various fundamental experiments including durability and time-dependent deformation are performed to compile a database for a utilization of high-strength concrete for PSC bridges. In the mix design, concrete strength at early age when prestressing forces are introduced to the PSC member and slumpflow suitable for pumping of concrete are considered to make a concrete fit for PSC bridges. The main parameters investigated are the kinds and replacement ratios of mineral admixtures and low-heat cement. Experimental tests on durability include penetration of chloride ions, freezing-thawing, combined deterioration, and simple adiabatic temperature rise test. In addition, time-dependent deformation such as creep, drying and autogenous shrinkage, which is particularly important factor in the design and construction of PSC bridges, is tested and analyzed.

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TWO TONNEL PROJECTS IN SWELLING ROCKS

  • Lee, Young-Nam;Ha, H.B.
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1990년도 PROCEEDINGS OF THE FIRST KOREA-JAPAN JOINT GEOTECHNICAL SEMINAR ON EXCAVATION and TUNNELING IN URBAN AREAS
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    • pp.35-50
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    • 1990
  • This paper describes the importance of incorporating the titre-dependent deformation behaviour in the design and construction of tunnels in swelling rocks. Two tunnel projects, in which authors got involved in Canada, are chosen to demonstrate the importance. In diversion tunnels for Oldman River Dan Projects time-dependent deformation characteristics of the mudrocks obtained from teat tunnel program were neglected in the design and construction of the tunnels and several sectional of concrete lining in tunnels were cracked extensively. In SABNGS No.3 Projects an extensive experimental program was carried out to study time-dependent deformation behaviour of highly swelling Queenston shale, with the air of establishing the constitutional relationship for the rock-structure time interaction analysis.

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가변 중력장하의 밀폐 용기 내 자연 대류 (Natural Convection in an Enclosure under Time Dependent Gravity)

  • 김기현;현재민;곽호상
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 추계학술대회논문집B
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    • pp.556-561
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    • 2000
  • Comprehensive numerical computations are made of side-heated squire cavity which is exposed to time dependent external mechanical forcing. Numerical solutions are acquires to the governing two-dimensional Navier-Stokes equations for a Boussinesq fluid. Time dependent heat transfer characteristics of interior fluid are analyzed to illustrate resonance phenomenon. When system is exposed to pure sinusoidal mechanical forcing, the numerical results disclose that the basic mechanism of resonance of mechanical forcing is same as that of thermal forcing of Ref. [3, 9]. In comparatively small amplitude of mechanical forcing, thermal characteristics of the system are similar to basic system(${\varepsilon}=0$).

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Eigenvoice 병합을 이용한 연속 음성 인식 시스템의 고속 화자 적응 (Rapid Speaker Adaptation for Continuous Speech Recognition Using Merging Eigenvoices)

  • 최동진;오영환
    • 대한음성학회지:말소리
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    • 제53호
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    • pp.143-156
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    • 2005
  • Speaker adaptation in eigenvoice space is a popular method for rapid speaker adaptation. To improve the performance of the method, the number of speaker dependent models should be increased and eigenvoices should be re-estimated. However, principal component analysis takes much time to find eigenvoices, especially in a continuous speech recognition system. This paper describes a method to reduce computation time to estimate eigenvoices only for supplementary speaker dependent models and to merge them with the used eigenvoices. Experiment results show that the computation time is reduced by 73.7% while the performance is almost the same in case that the number of speaker dependent models is the same as used ones.

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Probabilistic time-dependent sensitivity analysis of HPC bridge deck exposed to chlorides

  • Ghosh, Pratanu;Konecny, Petr;Lehner, Petr;Tikalsky, Paul J.
    • Computers and Concrete
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    • 제19권3호
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    • pp.305-313
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    • 2017
  • A robust finite element based reinforced concrete bridge deck corrosion initiation model is applied for time-dependent probabilistic sensitivity analysis. The model is focused on uncertainties in the governing parameters that include variation of high performance concrete (HPC) diffusion coefficients, concrete cover depth, surface chloride concentration, holidays in reinforcements, coatings and critical chloride threshold level in several steel reinforcements. The corrosion initiation risk is expressed in the form of probability over intended life span of the bridge deck. Conducted study shows the time-dependent sensitivity analysis to evaluate the significance of governing parameters on chloride ingress rate, various steel reinforcement protection and the corrosion initiation likelihood. Results from this probabilistic analysis provide better insight into the effect of input parameters variation on the estimate of the corrosion initiation risk for the design of concrete structures in harsh chloride environments.

공기식 집열창 시스템이 설치된 건물의 동적부하 해석 (Time Dependent Thermal Load Analysis of the Building with an Airflow Window System)

  • 조성환;박상동
    • 설비공학논문집
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    • 제4권2호
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    • pp.82-95
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    • 1992
  • It has been known that the application of an airflow window system reduces the energy consumption compared with conventional double pane window in a building. But how to analyze thermal load in a building with an airflow window system has not been well known. so two kinds of method (Mode 1 and Mode 2) to analyze time dependent thermal load of the building with an airflow window system are presented in this study. The results of load analysis about the model building(total area : $4521m^2$, 3 floors) by Mode 2 show that the maximum cooling and heating load in a building with an airflow window system are decreased about 12-17% and about 19.5% than with double pane glass window, and yearly energy consumption with an airflow window system is saved about about 20% than with double pane glass window.

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