• 제목/요약/키워드: Building parameterization

검색결과 14건 처리시간 0.02초

CFD 모델을 이용한 건물군 주변의 흐름 특성 연구 (A Study on the Characteristics of Flows around Building Groups Using a CFD Model)

  • 이한경;김재진;이영곤
    • 대기
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    • 제25권3호
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    • pp.501-510
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    • 2015
  • In this study, the characteristics of flows around building groups are investigated using a computational fluid dynamics (CFD) model. For this, building groups with different volumetric ratios in a fixed area are considered. As the volumetric ratio of the building group increases, the region affected by the building group is widened. However, the wind-speed reduced area rather decreases with the volumetric ratio near the ground bottom (z ${\lesssim}$ 0.7H, here, H is the height of the building group) and, above 0.7H, it increases. As the volumetric ratio decreases (that is, space between buildings was widened), the size of recirculation region decreases but flow recovery is delayed, resulting in the wider wind-speed reduced area. The increase in the volumetric ratio results in larger drag force on the flow above the roof level, consequently reducing wind speed above the roof level. However, above z ${\gtrsim}$ 1.7H, wind speed increases with the volumetric ratio for satisfying mass conservation, resultantly increasing turbulent kinetic energy there. Inside the building groups, wind speed decreased with the volumetric ratio and averaged wind speed is parameterized in terms of the volumetric ratio and background flow speed. The parameterization method is applied to producing averaged wind speed for 80 urban areas in 7 cities in Korea, showing relatively good performance.

Robust finite element model updating of a large-scale benchmark building structure

  • Matta, E.;De Stefano, A.
    • Structural Engineering and Mechanics
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    • 제43권3호
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    • pp.371-394
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    • 2012
  • Accurate finite element (FE) models are needed in many applications of Civil Engineering such as health monitoring, damage detection, structural control, structural evaluation and assessment. Model accuracy depends on both the model structure (the form of the equations) and the model parameters (the coefficients of the equations), and can be generally improved through that process of experimental reconciliation known as model updating. However, modelling errors, including (i) errors in the model structure and (ii) errors in parameters excluded from adjustment, may bias the solution, leading to an updated model which replicates measurements but lacks physical meaning. In this paper, an application of ambient-vibration-based model updating to a large-scale benchmark prototype of a building structure is reported in which both types of error are met. The error in the model structure, originating from unmodelled secondary structural elements unexpectedly working as resonant appendages, is faced through a reduction of the experimental modal model. The error in the model parameters, due to the inevitable constraints imposed on parameters to avoid ill-conditioning and under-determinacy, is faced through a multi-model parameterization approach consisting in the generation and solution of a multitude of models, each characterized by a different set of updating parameters. Results show that modelling errors may significantly impair updating even in the case of seemingly simple systems and that multi-model reasoning, supported by physical insight, may effectively improve the accuracy and robustness of calibration.

부산지역 빌딩 분포 상세화에 따른 중규모 순환 특성 (Characteristics of Mesoscale Circulation with the Detailed Building Distribution in Busan Metropolitan Area)

  • 손정옥;이화운;이순환
    • 한국환경과학회지
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    • 제21권2호
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    • pp.203-215
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    • 2012
  • In order to clarify the impacts of thermal difference in atmospheric boundary layer due to the different sophistication of building information in Busan metropolitan areas, several numerical simulations were carried out. ACM (Albedo Calculation Model) and WRF (Weather Research and Forecasting) was applied for estimating albedo and meteorological elements in urban area, respectively. In comparison with coarse aggregated and small buildings, diurnal variation of albedo is highly frequent and its total value tend to be smaller in densely aggregated and tall buildings. Estimated TKE and sensible heat flux with sophisticatedly urban building parameterization is more resonable and valid values are mainly induced by urban building sophistication. The simulation results suggest that decreased albedo and increased roughness due to skyscraper plays an important role in the result of thermal change in atmospheric boundary layer.

비정형 건축물의 외장재 제작 시공을 위한 3D 스캐닝에 의한 역 설계 프로세스 검토 (Review of Reverse Design Process for Freeform Envelope Using 3D Scanning)

  • 김성진;박성진;류한국
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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    • pp.17-18
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    • 2015
  • In manufacturing industry, image scanning technique has made enormous progress in past decades. 3D models have been also very important to continuously monitor the related spatial information for freeform buildings. The process of shape making of 3D scanning is as follows: mesh surface segmentation, NURBS surface generation, and parametric solid model generation. We will review the process and applying process. Especially in the construction industry, 3D data collection by laser scanning has become an high quality 3D models. Therefore, in this research, we have an effort to review construction of reverse design process for freeform envelope using 3D scanning. The technology enables many 3D shape engineering and design parameterization of reverse engineering in the construction site.

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해양 생태모델링 고찰 (A Brief Introduction to Marine Ecosystem Modeling)

  • 김해철;조양기
    • 한국해양학회지:바다
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    • 제18권1호
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    • pp.21-31
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    • 2013
  • 생태모델은 생태계 구성 요소간의 관계를 수치적으로 표현하여 생태계 내에 존재하는 다양한 요인들의 시간에 따른 내재적 변동과 외부 조건의 변화에 따른 반응을 예측하는데 유용한 도구다. 해양 생태모델은 학제간 공동 연구결과를 토대로, 보다 체계적이고 종합적인 접근 방법을 통해, 최근 수 십 년 동안 많은 발전을 이룩하였다. 이 글은 해양 생태모델의 이론적 배경을 살피고, 모델 수립 시 고려해야 할 사항 및 최근 동향에 대하여 소개한다.

비정형 건축물의 외장 패널의 선제작과 시공을 위한 역설계 프로세스와 사례 분석을 통한 시사점 도출 (Implications Deduction through Analysis of Reverse Engineering Process and Case Study for Prefabrication and Construction of Freeform Envelop Panels)

  • 류한국;김성진
    • 한국건축시공학회지
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    • 제16권6호
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    • pp.579-585
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    • 2016
  • 3차원 이미지 스캐닝 기술은 복잡한 비정형 건축물의 외피의 정확한 형상과 위치 데이터를 확보하는데 효과적이다. 3차원 이미지 스캐닝 기술의 세부 과정인 점 군집화, 메쉬표면 분리, 넙스 표면 생성, 파라메트릭 솔리드 모델을 통하여 비정형 건축물의 형상을 구축할 수 있다. 이에 본 연구는 비정형 건축물의 외장재 제작과 시공을 위한 3차원 이미지 스캐닝에 의한 역설계 프로세스와 사례 분석을 통하여 시사점을 도출한다. 본 연구의 결과는 역설계 기술을 사용한 3차원 형상 기술과 설계 요소화 방법을 다양한 건설 프로젝트에 활용할 수 있을 것으로 판단된다.

도심 실제 거칠기 적용과 장래 도심 개발계획에 따른 국지 기상장 변화 수치 모의 (The Effect of Atmospheric Flow Field According to the Urban Roughness Parameter and the Future Development Plan on Urban Area)

  • 최현정;이화운;김민정
    • 한국환경과학회지
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    • 제19권6호
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    • pp.703-714
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    • 2010
  • In this study, we analyzed the impact of orographic and thermal forcing on the atmospheric flow field over the urban metropolitan areas on urban artificial buildings and future development plan. Several numerical experiments have been undertaken in order to clarify the impacts of the future development plan on urban area by analyzing practical urban ground conditions, we revealed that there were large differences in the meteorological differences in each case. The prognostic meteorological fields over complex areas of Seoul, Korea are generated by the PSU/NCAR mesoscale model(MM5). we carried out a comparative examination on the meteorological fields of topography and land-use that had building information and future development plan. A higher wind speed at daytimes tends to be forecasted when using new topography and land use data that have a high resolution with an appropriate limitation to the mixing height and the nocturnal boundary layer(NCB). During nighttime periods, since radiation cooling development is stronger after development plan, the decreased wind speed is often generated.

감지 패턴 인식에 의한 가스센서의 선택성 연구 (A Study on the Selectivity of Gas Sensors by Sensing Pattern Recognition)

  • 이성필
    • 센서학회지
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    • 제20권6호
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    • pp.428-433
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    • 2011
  • We report on the building of a micro sensor array based on typical semiconductor fabrication processes aimed at monitoring selectively a specific gas in ambient of other gases. Chemical sensors can be applied for an electronic nose and/or robots using this technique. Microsensor array was fabricated on the same chip using 0.6${\mu}m$ CMOS technology, and unique gas sensing patterns were obtained by principal component analysis from the array. $SnO_2$/Pt sensor for CO gas showed a high selectivity to buthane gas and humidity. $SnO_2$ sensor for hydrogen gas, however, showed a low selectivity to CO and buthane gas. We can obtain more distinguishable patterns that provide the small sensing deviation(the high seletivity) toward a given analyte in the response space than in the chemical space through the specific parameterization of raw data for chemical image formation.

L4/L5 디스크 환자 진단을 위한 동적 근전도 신호의 정량화 기법 개발 (Parameterization of Dynamic Electromyographic Signal for Diagnosing L4/L5 Disc Patients)

  • 현수돈;김정룡
    • 대한산업공학회지
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    • 제24권2호
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    • pp.297-309
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    • 1998
  • Numerical parameters have been developed to diagnose L4/L5 disc patients during repetitive flexions and extensions. Electromyography(EMG) has been used to define the muscle excitation and movement cycle in this study. Twenty healthy subjects and twenty L4/L5 disc patients were recruited for the experiment. The subjective pain levels of patients were recorded as $3.7{\pm}1.6$ according to visual analogue scale where 10 was the maximum pain level. Variance ratio of motion cycle was suggested as a new parameter to examine the consistency of the trunk movement. The results indicated that the temporal EMG pattern such as peak time difference between Quadriceps and Hamstrings, the duration of coexcitation between Erector spinae and Rectus abdominis muscle pairs showed a statistically significant difference between healthy subjects and patients. Variance ratio of External oblique and Internal oblique also showed a statistically significant difference. It is expected that those results could be used for diagnosis by building a database for various back pain patients and healthy subjects. This method can eventually help physicians for early diagnosis and prevention of low back disorders.

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전역 최적화기법과 파라메트릭 변환함수를 이용한 선형 최적화 (Hull Form Optimization using Parametric Modification Functions and Global Optimization)

  • 김희정;전호환;안남현
    • 대한조선학회논문집
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    • 제45권6호
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    • pp.590-600
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    • 2008
  • This paper concerns the development of a designer friendly hull form parameterization and its coupling with advanced global optimization algorithms. As optimization algorithms, we choose the Partial Swarm Optimization(PSO) recently introduced to solve global optimization problems. Most general-purpose optimization softwares used in industrial applications use gradient-based algorithms, mainly due to their convergence properties and computational efficiency when a relatively few number of variables are considered. However, local optimizers have difficulties with local minima and non-connected feasible regions. Because of the increase of computer power and of the development of efficient Global Optimization (GO) methods, in recent years nongradient-based algorithms have attracted much attention. Furthermore, GO methods provide several advantages over local approaches. In the paper, the derivative-based SQP and the GO approach PSO are compared with their relative performances in solving some typical ship design optimization problem focusing on their effectiveness and efficiency.