• 제목/요약/키워드: physically based model

검색결과 250건 처리시간 0.029초

도시침수 모의 기술 국내 연구동향 리뷰: 2001-2022 (A review on urban inundation modeling research in South Korea: 2001-2022)

  • 이승수;김보미;최현진;노성진
    • 한국수자원학회논문집
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    • 제55권10호
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    • pp.707-721
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    • 2022
  • 본 총설연구에서는 도시침수 모의 기술의 체계와 발전 과정을 정리하고, 주요 성과와 한계점을 파악하여 향후 연구 방향과 도전 과제를 제시하였다. 이를 위해 2000년대 이후 국내 주요 학술논문집에 수록된 도시침수 모의 관련 논문 160여편을 분석하여 연구의 핵심 주제와 내용을 살펴본 후, 물리 및 데이터 기반 모형의 침수모의 세부 방법론별로 기술의 발전 현황에 대해 정리하였다. 또한, 국내 도시침수 모의 기술의 활용목적별 동향, 국외 및 연관 분야 연구동향에 대해서도 분석하였다. 국내 도시침수 모의 연구에서 Storm Water Management Model (SWMM) 모형을 활용하는 비율이 60%를 넘는 것으로 조사되었으며, 이중 배제(dual drainage)의 도시침수 물리 과정을 상세히 해석하는 국내 기술에 대한 연구가 필요한 것으로 판단되었다. 한편, 딥러닝(deep learning) 등 데이터 기반 모의 기술은 도시침수 해석의 새로운 분야로 자리매김하였다. 다만, 모형 훈련을 위한 극한기상조건에 대한 침수자료는 관측 만으로 확보할 수 없으므로, 고정확도 물리 모형과 데이터 기반 모형 연구는 상호보완적으로 진행되어야 할 필요가 있다. 도시침수 모의 기술은 인공지능이나 IoT, 메타버스 등 타 분야 신기술과의 접목이 활발히 이루어지고 있으며, 기후 위기 적응과 재해 피해 저감을 위해 지속적인 사회적 투자와 융합 연구가 필요한 분야로 판단된다.

Terrain Geometry from Monocular Image Sequences

  • McKenzie, Alexander;Vendrovsky, Eugene;Noh, Jun-Yong
    • Journal of Computing Science and Engineering
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    • 제2권1호
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    • pp.98-108
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    • 2008
  • Terrain reconstruction from images is an ill-posed, yet commonly desired Structure from Motion task when compositing visual effects into live-action photography. These surfaces are required for choreography of a scene, casting physically accurate shadows of CG elements, and occlusions. We present a novel framework for generating the geometry of landscapes from extremely noisy point cloud datasets obtained via limited resolution techniques, particularly optical flow based vision algorithms applied to live-action video plates. Our contribution is a new statistical approach to remove erroneous tracks ('outliers') by employing a unique combination of well established techniques-including Gaussian Mixture Models (GMMs) for robust parameter estimation and Radial Basis Functions (REFs) for scattered data interpolation-to exploit the natural constraints of this problem. Our algorithm offsets the tremendously laborious task of modeling these landscapes by hand, automatically generating a visually consistent, camera position dependent, thin-shell surface mesh within seconds for a typical tracking shot.

Tangible Space and Interactive Technology

  • Yoon, Joong-Sun;Yoh, Myeung-Sook
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.2687-2692
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    • 2003
  • Recent advancement in information technology requires new interpretations for the space among human, machines and environment. Investigation of space between information and human could lead to the proper ways, in which human and machines meet. Various concepts regarding space have been explored in terms of “virtual reality in cyberspace” and “embodiment in tangible space.” “Mom (embodiment),” space, virtuality, sensation/perception, and interactive technology are some of the key ideas to be explored. Human “Mom” is such a fundamental membrane through which human can interact with the environment physically and mentally. An embodied interaction paradigm, based on “Mom,” is investigated. This leads to interactive technology paradigm. Sound space is an invisible but a tangible space in a sense that it travels in emotional tremors and stimulates new sensations and perceptions. Three cases are introduced to experiment such tangible space as a new and proper interactive paradigm. Also, a historical model of interaction is reviewed, which includes electrical, symbolic, textual, graphical, tangible, and social interaction.

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RLSE Based Batteryless Telemetry Capacitive Sensor System

  • Lee, Joon-Tark;Kim, Kyung-Yup
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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    • pp.318-321
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    • 2003
  • In case, sensor system performs where it is difficult to access physically and it is in the poor environment, it is limited to communicate by using wire and installing power module in sensor system. In this paper, it suggests how information is obtained from telemetry sensor by means of inductive coupling without battery. Comparing with the telemetry sensor system of inductive coupling by the power supply, this system estimates the capacitance of sensor with high precision in using RLSE, not the process of modulation and demodulation. In order to activate this system, inductive model is used and in case of time variant parameter, telemetry sensor system which has got high rate in accuracy is implemented by using the forgetting factor.

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Use of uniform distribution for generating synthetic brightness temperature in passive microwave soil moisture retrieval

  • Lee Khil-Ha
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2005년도 학술발표회 논문집
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    • pp.19-28
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    • 2005
  • Passive microwave remote sensing technique have shown great potential for mon monitoring regional/global surface soil moisture. Given a single measurement at dual polarization/single frequency/single view angle, a strategic approach to artificially generating multiple microwave brightness temperatures is presented. And then the statistically generated microwave brightness temperature data are applied to the inverse algorithm, which mainly relies on a physically based microwave emission model and an advanced single-criterion multi-parameter optimization technique, to simultaneously retrieve soil moisture and vegetation characteristics. . The procedure is tested with dual polarized Tropical Rainfall Measurement Mission Microwave Imager (TRMM/TMI) over two different cover sites in Oklahoma and Beltsville field experimental data. The retrieval results are analyzed and show excellent performance.

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화력발전소 증기터빈용 12Cr 강의 저주기 피로거동 (Low Cycle Fatigue Behavior of 12Cr Steel for Thermal Power Plant Steam Turbine)

  • 강명수
    • 한국정밀공학회지
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    • 제19권8호
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    • pp.71-76
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    • 2002
  • In this study low cycle fatigue (LCF) behavior of 12Cr steel at high temperature are described. Secondly, comparisons between predicted lives and experimental lives are made for the several sample life prediction models. Two minute hold period in either tension or compression reduce the number of cycles to failure by about a factor of two. Twenty minute hold periods in compression lead to shorter lives than 2 minute hold periods in compression. Experiments showed that life predictions from classical phenomenological models have limitations. More LCF experiments should be pursued to gain understanding of the physical damage mechanisms and to allow the development of physically-based models which can enhance the accuracy of the predictions of components. From a design point-of-view, life prediction has been judged acceptable for these particular loading conditions but extrapolations to thermo-mechanical fatigue loading, for example, require more sophisticated models including physical damage mechanisms.

Energy and Mass Balance of Snowpack - Rapid snowmelt during Fohn events in the Takada plain -

  • 김선주
    • 한국농공학회지
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    • 제32권E호
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    • pp.88-94
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    • 1990
  • Several models physically based to predict the evolution of the snowpack have been proposed. Validity of these models for hourly estimation is, however, questionable, since they have been tested only on a daily basis. A computational model to predict the amount of snowpack on an hourly basis in terms of snowload from a set of meterological measurements was developed and investigated the rapid snowmelt conditions during Fohn events in the Takada plain.

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완전용입 풀의 진동을 이용한 형상측정에 관한 연구 (A Study on Weld Pool Oscillation for Pool Geometry Measurement)

  • 유중돈
    • Journal of Welding and Joining
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    • 제11권2호
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    • pp.62-73
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    • 1993
  • Weld pool oscillation for the full-penetration GTA welding process was investigated for its possible application to weld penetration control through theoretical modeling and experiment. Energy method was used to estimate the natural frequency of the molten pool having the physically-acceptable weld geometry and oscillation modes. An unique experimental system was built which had the data acquisiton and video capabilities so that the pool oscillation signals and molten pool surfaces could be monitored continuously. Pool oscillation was detected through arc voltage and arc light emission simultaneously. The signal from arc light emission showed good coherence with that from arc voltage, and arc light generated the higher quality signal. The molten pool was found to oscillate in different oscillation modes based on the travel speed and weld geometry. The natural frequency estimated from the theoretical model agreed reasonably well with the experimental results.

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경안천 유역에 대한 MIKE SHE모형의 적용 (Application of MIKE SHE Modeling System to the Gyeongancheon Watershed)

  • 임상준;김현준;장철희
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2003년도 학술발표논문집
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    • pp.463-466
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    • 2003
  • The physically based distributed modelling system, MIKE SHE, has been applied to the upper sub-watershed of the Gyeongancheon watershed. A horizontal grid square was constructed to represent the spatial variations in watershed characteristics, landuse, soil, and rainfall distributions. The hydraulic model MIKE 11 was also coupled with the MIKE SHE to simulate river flow in the main and tributaries of Gyeongancheon. The simulated daily stream flow at the outlet of the watershed was compared to the observed data for the period of 1988 to 1991. The results demonstrated the applicability of a comprehensive hydrological modelling system as management tool for watershed and floodplain.

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Complete Identification of Isotropic Configurations of a Caster Wheeled Mobile Robot with Nonredundant/Redundant Actuation

  • Kim Sung-Bok;Moon Byung-Kwon
    • International Journal of Control, Automation, and Systems
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    • 제4권4호
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    • pp.486-494
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    • 2006
  • In this paper, we present the complete isotropy analysis of a caster wheeled omnidirectional mobile robot (COMR) with nonredundant/redundant actuation. It is desirable for robust motion control to keep a COMR close to the isotropy but away from the singularity as much as possible. First, with the characteristic length introduced, the kinematic model of a COMR is obtained based on the orthogonal decomposition of the wheel velocities. Second, a general form of the isotropy conditions of a COMR is given in terms of physically meaningful vector quantities which specify the wheel configuration. Third, for all possible nonredundant and redundant actuation sets, the algebraic expressions of the isotropy conditions are derived so as to identify the isotropic configurations of a COMR. Fourth, the number of the isotropic configurations, the isotropic characteristic length, and the optimal initial configuration are discussed.