• 제목/요약/키워드: physical scale modeling

검색결과 94건 처리시간 0.029초

역T형 옹벽의 지진시 거동특성 Part I : 수치해석 모델링 기법의 검증 (Seismic Behavior of Inverted T-type Wall under Earthquake Part I : Verification of the Numerical Modeling Techniques)

  • 이진선
    • 한국지진공학회논문집
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    • 제20권1호
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    • pp.1-8
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    • 2016
  • Permanent deformation plays a key role in performance based earthquake resistant design. In order to estimate permanent deformation after earthquake, it is essential to secure reliable response history analysis(RHA) as well as earthquake scenario. This study focuses on permanent deformation of an inverted T-type wall under earthquake. The study is composed of two separate parts. The first one is on the verification of RHA and the second one is on an effect of input earthquake motion. The former is discussed in this paper and the latter in the companion paper. The verification is conducted via geotechnical dynamic centrifuge test in prototype scale. Response of wall stem, ground motions behind the wall obtained from RHA matched pretty well with physical test performed under centrifugal acceleration of 50g. The rigorously verified RHA is used for parametric study to investigate an effect of input earthquake motion selection in the companion paper.

On scale-dependent stability analysis of functionally graded magneto-electro-thermo-elastic cylindrical nanoshells

  • Asrari, Reza;Ebrahimi, Farzad;Kheirikhah, Mohammad Mahdi
    • Structural Engineering and Mechanics
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    • 제75권6호
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    • pp.659-674
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    • 2020
  • The present paper employs nonlocal strain gradient theory (NSGT) to study buckling behavior of functionally graded magneto-electro-thermo-elastic (FG-METE) nanoshells under various physical fields. NSGT modeling of the nanoshell contains two size parameters, one related to nonlocal stress field and another related to strain gradients. It is considered that mechanical, thermal, electrical and magnetic loads are exerted to the nanoshell. Temperature field has uniform and linear variation in nanoshell thickness. According to a power-law function, piezo-magnetic, thermal and mechanical properties of the nanoshell are considered to be graded in thickness direction. Five coupled governing equations have been obtained by using Hamilton's principle and then solved implementing Galerkin's method. Influences of temperature field, electric voltage, magnetic potential, nonlocality, strain gradient parameter and FG material exponent on buckling loads of the FG-METE nanoshell have been studied in detail.

Simulation of Electric Vehicles Combining Structural and Functional Approaches

  • Silva, L.I.;Magallan, G.A.;De La Barrera, P.M.;De Angelo, C.H.;Garcia, G.O.
    • Journal of Electrical Engineering and Technology
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    • 제9권3호
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    • pp.848-858
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    • 2014
  • In this paper the construction of a model that represents the behavior of an Electric Vehicle is described. Both the mechanical and the electric traction systems are represented using Multi-Bond Graph structural approach suited to model large scale physical systems. Then the model of the controllers, represented with a functional approach, is included giving rise to an integrated model which exploits the advantages of both approaches. Simulation and experimental results are aimed to illustrate the electromechanical interaction and to validate the proposal.

Application of QuickBird Satellite Image to Storm Runoff Modeling

  • Kim, Sang-Ho;Lee, Mi-Seon;Park, Geun-Ae;Kim, Seong-Joon
    • 대한원격탐사학회지
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    • 제23권1호
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    • pp.15-20
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    • 2007
  • This study is to apply QuickBird satellite image for the simulation of storm runoff in a small rural watershed. For a $1.05km^2$ watershed located in Goesan-Gun of Chungbuk Province, the land use from the QuickBird image was produced by on-screening digitising after ortho-rectifying using 2 m DEM. For 3 cases of land use, soil and elevation scale (1:5,000, 1:25,000 and 1:50,000), SCS-CN and the watershed physical parameters were prepared for the storm runoff model, HEC-HMS (Hydrologic Modelling System). The model was evaluated for each case and compared the simulated results with couple of selected storm events.

가상 조작기를 이용한 3D 모델링 및 시뮬레이션 (3D Modeling and Simulation using Virtual Manipulator)

  • 박희성;김호동
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2011년도 춘계학술발표대회
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    • pp.547-550
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    • 2011
  • The purpose of this paper is to verify and validate the maintenance tasks of the construction of a nuclear facility using a digital mock-up and simulation technology instead of a physical mock-up. Prior to the construction of a nuclear facility, a remote simulator that provides the opportunity to produce a complete digital mock-up of the PRIDE (Pyroprocess Integrated Inactive DEmonstration Facility) region and its remote handling equipment, including operations and maintenance procedures has been developed. In this paper, the system architecture and graphic user interface of a remote simulator that coincides with the extraordinary nature of a nuclear fuel cycle facility is introduced. In order to analyze the remote accessibility of a remote manipulator, virtual prototyping that was performed it by using haptic device of external input devices under a 3D full-scale digital mock-up is explained.

치과기공사의 건강관련 삶의 질에 영향을 미치는 심신 자각증상 요인에 관한 연구 (A study of the psychosomatic self-reported symptom factors affecting health-related quality of life(HRQOL) among the dental technicians)

  • 권순석;백승학
    • 대한치과기공학회지
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    • 제33권1호
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    • pp.79-92
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    • 2011
  • Purpose: This study is to present substantial data for the development of practicable health related programs with which the dental technicians can enjoy better quality of life. To this end, we have surveyed the self-reported psychosomatic symptoms of the dental technicians in Korea and figured out their current health problems. Methods: Out of the random selection of the registered dental offices of Dental Technicians in Korea, 2,000 working dental technicians were asked to fill out the questionnaire from January 19 to April 30, 2009. We collected the 1,525 sheets of the questionnaire and took frequency analysis, t-test, analysis of variance and structural equation modeling using SPSS Win 12.0 and AMOS program. Results: Concerning the modes of the subjects' appealing of their psychosomatic self-symptoms, scale point of the mental health turned out 18.68, which is higher than the physical health that scored 17.28. In the case of the results from the standardized scores of the sub items, scale point of aggressiveness scored the highest(20.14), whereas that of mouth and annus scored the lowest (15.29). Additionally, the overall satisfaction rates of the health related quality of life was 67.89. Regarding the health related quality of life, self reported mental symptoms(-.736) was more influential than physical symptoms(0.29). Conclusion: The psychosomatic self reported symptoms of the dental technicians proved higher than other occupations, whereas health related quality of life was very low. Consequently, it seems vital to lessen the mental symptoms and the sub items concerned.

디지털 트윈 개념을 적용한 프로토타이핑 기반 디자인 프로세스: 기초연구 (Prototyping-based Design Process Integrated with Digital-Twin: A Fundamental Study)

  • 김진웅;김성아
    • 한국BIM학회 논문집
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    • 제9권4호
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    • pp.51-61
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    • 2019
  • In the general manufacturing sector, prototyping used to reduce the risks that can arise with new conceptual products. However, in AEC area, it does not mass-produce a building, so the prototype itself becomes a building. Therefore, it is challenging to have prototyping of the same scale as the real thing, and the prototyping process in architecture is very inefficient. The prototyping process in the design stage typically assumes making a scaled model, partial model, or digital model. However, it is difficult for these models to correspond to the actual building and the environment of time and space such as scale, material, environment, load, physical properties and deformation, corrosion, etc., unlike the actual building. When using the digital twin concept in the prototyping process, it is possible to measure performance from the design stage to the operation stage. The digital twin was found by a method for monitoring based on physical twins and real-time linkage in the operation stage. Therefore, if the digital twin concept is applied at the design stage, it is possible to predict performance using not only current performance but also history information using real-time information. In order to apply the digital twin concept to the prototyping design process, we analyze the theoretical considerations and the prototyping design process of the digital twin, analyze the cases and research results where the prototyping design was applied, Provide an applied prototyping design process. The proposed process is tested through a pilot project and analyzed for potential use.

인터넷 통신에서 고속 TCP 프로토타입을 이용한 지연 제어 (Delay Control using Fast TCP Prototype in Internet Communication)

  • 나하선;김광준;나상동
    • 한국정보통신학회논문지
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    • 제7권6호
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    • pp.1194-1201
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    • 2003
  • 본 논문에서는 고속 프로토타입 TCP 트래픽 제어 프레임워크를 TCP 기반의 신뢰할 수 있는 전송 및 윈도우 기반 혼잡제어로 확대한다. TCP의 소요 대역폭 응답의 적극성을 LTS(large time scale) 네트워크 상태의 함수 형태, 즉 RTT(round-trip time)가 결정한 피드백 루프의 한계를 넘어서는 정보의 형태로 조정하는 LTS 모듈과 TCP를 연계시키는 방법으로 수행한다. 특히, TCP 트래픽의 ACK를 지연시키는 메커니즘을 제시하고, 제어된 ACK 흐름은 TCP 활동의 트래픽 특성을 비교 평가한다. 링크 사용 또는 버퍼 점유에 대한 정보를 사용함으로서 혼잡 제어에 대한 ACK 지연을 통보할 수 있고, ACK 지연 메커니즘을 다양한 네트워크 노드에서 구현된다. 본 논문에서는 이러한 혼잡 제어를 통한 연결의 공정성 뿐 아니라 고속 TCP 프로토타입이 패킷 손실을 보다 효과적으로 줄이며, 시뮬레이션 결과를 통해 요구된 버퍼 크기에 대한 처리량이 뛰어남을 입증하였다.

자기유사성 네트워크에서 트래픽 제어에 의한 성능 개선 (Adaptive Data Hiding Techniques for Secure Communication of Images)

  • 석경휴;나상동
    • 한국통신학회논문지
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    • 제29권6B호
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    • pp.575-583
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    • 2004
  • 본 논문에서는 MTS 정체 프레임워크를 윈도우 기반 정체 제어, 특히 TCP로 확장하고 TCP의 대역폭 소비 반응의 적극성을 LTS 자기유사성 네트워크 상태의 함수 형태에서 연구한다. RTT가 결정한 피드백 루프의 시간 한계를 초과하는 정보의 형태로 조정하는 LTS 제어모듈과 TCP를 연계시키는 방법으로 연구하며, 또 정보는 개연적인 특성을 갖고 여러 시간대에 걸쳐 분산되는 기존 윈도우를 기반으로 실현되기 때문에, 이를 효과적으로 활용할 수 있는 방법으로 개선하고, MTS TCP의 성능을 자기 유사성 트래픽의 물리적 모델링에 기반 한 시뮬레이션을 벤치마크 환경을 통해 수행된다. 본 논문은 자기유사성 트래픽 조건에서 프로토콜 스택의 전송 프로토콜 변화의 영향을 파악 및 평가하는 방법론을 활용하고, 과중한 워크로드 조건에서 시뮬레이션을 통해 성능 개선을 평가 비교한다.

Exploring the Latent Trait and the Measurement Properties of Korean World Health Organization Quality of Life-BREF Measure Applied to Cancer Survivors

  • Bongsam Choi
    • 한국전문물리치료학회지
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    • 제30권2호
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    • pp.120-127
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    • 2023
  • Background: In general, measurement qualities of cross-culturally adapted quality of life (QOL) measures are altered in many aspects, although versions of them are well-validated measures. The latent trait and measurement qualities of the QOL measures for cancer-related samples should be considered when developing cross-culturally adapted measures. Objects: To investigate the latent trait of the translated into Korean World Health Organization Quality of Life-BREF (WHOQOL-BREF) administered to different cancer survivors who had palliative rehabilitation care service (PRCS). Methods: A cross-sectional study with 139 cancer survivors who had an experience of cancer survivorship with PRCS were conducted with a two-step analytic procedure including exploratory factor analysis (EFA) to confirm the latent trait and Rasch rating scale modeling to investigate the measurement qualities of the cross-culturally adapted WHOQOL-BREF measure. Results: While the original WHOQOL-BREF measure constitutes a 4-latent trait, the EFA reveals that 24 items constitute six substantial factors. The item loadings are predominantly spread over factors 1 through 4 in a mixed manner of the latent traits, while the loadings of 'physical health' and 'environmental health' latent traits show similarity to what the original measure intended to assess. The latent trait of the cross-culturally adapted WHOQOL-BREF measure administered to different cancer survivors is likely to reveal more dimensions than the original WHOQOL-BREF measure. Person reliability (i.e., analogous to Cronbach's alpha) and separation are measured with 0.92 and 3.48, respectively. All items except the one item (medical treatment item) fit the Rasch rating model. Conclusion: Findings suggest that the latent trait and the measurement qualities of the cross-culturally adapted WHOQOL-BREF measure should be taken into consideration when applying versions of it to various populations.