• 제목/요약/키워드: Data Modelling

검색결과 1,273건 처리시간 0.027초

강우자료의 스케일 효과가 비선형수문반응에 미치는 영향 (Investigating the scaling effect of the nonlinear response to precipitation forcing in a physically based hydrologic model)

  • 오남선;이길하
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2006년도 학술발표회 논문집
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    • pp.149-153
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    • 2006
  • 강우는 물과 에너지 순환에서 가장 중요한 역할을 한다. 이 연구에서는 원격탐사를 이용하여 추출한 강우자료의 불확실성 (uncertainty)이 수치수문모형에서 수문인자 (토양함수, 토양온도, 유출, 증발산, 열전도 등)를 모의할 때 공간 스케일의 영향을 검토해 보았다. 지상강우관측을 이용하여 보정된 WSR-88D (NEXRAD)에 의해 추출한 강우자료와 현장에서 측정된 기상자료를 입력 자료로 사용하여, 오프라인 CLM(Community Land Model) 수문모형을 세 가지의 다른 공간 스케일 $0.25^{\circ},\;0.5^{\circ}\;and\;1.0^{\circ}$에 대하여 수행하였다. 이어서 현장에서 측정된 기상자료는 고정시키고 동시공간에 해당하는 IR (Infrared) 밴드를 기반으로 하는 인공위성 강우자료로 대치시켜 같은 모형을 수행하여 비교 검토하였다. 이 연구에서는 물리적 이론을 기반으로 하는 CLM수문모형의 매개변수는 지표면-대기의 수문반응 (land-atmosphere interaction)을 적절하게 묘사하도록 정의되었다고 가정한다. 모형의 실험결과는 강우입력의 불확실성이 수문반응의 공간분포 결과에 어떻게 영향을 미치는지를 보여준다. 이 연구는 수문모형을 수행할 때 수문반응의 불확실성에 대한 정보를 제공해 주며, 결국은 기후 변화에 따른 수자원의 재분배를 이해하는데 이바지 할 것이다.

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Accuracy Comparison Between Image-based 3D Reconstruction Technique and Terrestrial LiDAR for As-built BIM of Outdoor Structures

  • Lee, Jisang;Hong, Seunghwan;Cho, Hanjin;Park, Ilsuk;Cho, Hyoungsig;Sohn, Hong-Gyoo
    • 한국측량학회지
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    • 제33권6호
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    • pp.557-567
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    • 2015
  • With the increasing demands of 3D spatial information in urban environment, the importance of point clouds generation techniques have been increased. In particular, for as-built BIM, the point clouds with the high accuracy and density is required to describe the detail information of building components. Since the terrestrial LiDAR has high performance in terms of accuracy and point density, it has been widely used for as-built 3D modelling. However, the high cost of devices is obstacle for general uses, and the image-based 3D reconstruction technique is being a new attraction as an alternative solution. This paper compares the image-based 3D reconstruction technique and the terrestrial LiDAR in point of establishing the as-built BIM of outdoor structures. The point clouds generated from the image-based 3D reconstruction technique could roughly present the 3D shape of a building, but could not precisely express detail information, such as windows, doors and a roof of building. There were 13.2~28.9 cm of RMSE between the terrestrial LiDAR scanning data and the point clouds, which generated from smartphone and DSLR camera images. In conclusion, the results demonstrate that the image-based 3D reconstruction can be used in drawing building footprint and wireframe, and the terrestrial LiDAR is suitable for detail 3D outdoor modeling.

Numerical simulation of dimensional changes during sintering of tungsten carbides compacts

  • Bouvard, D.;Gillia, O.
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 1997년도 추계학술강연 및 발표대회 강연 및 발표논문 초록집
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    • pp.7-7
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    • 1997
  • During sintering of very porous green bodies, as obtained by compaction of hard powders - such as tungsten carbide or ceramics - or by injection moulding, important shrinkage occurs. Due to heterogeneous green density field, gravity effects, friction on the support, thermal gradients, etc., this shrinkage is often non-uniform, which' may induce significant shape changes. As the ratio of compact dimension to powder size is very high, the mechanics of continuum is relevant to model such phenomena. Thus numerical techniques, such as the finite element method can be used to simulate the sintering process and predict the final shape of the sintered part. Such type of simulation has much been developed in the last decade firstly for hot isostatic pressing and next for die compaction. Finite element modelling has been recently applied to free sintering. The simulation of sintering should be based on constitutive equations describing the thermo-mechanical behaviour of the material under any state of stress and any temperature which may arise within the sintering body. These equations can be drawn either from experimental data or from micromechanical models. The experiments usually consist in free sintering and sinter-forging tests. Indeed applying more complex loading conditions at high temperature under controlled atmosphere is delicate. Micromechanical models describe the constitutive behaviour of aggregates of spheres from the deformation of two-sphere contact either by viscous flow or grain boundary diffusion. Such models are not able to describe complex microstructure and mechanisms as observed in real materials but they can give some basic information on the formulation of constitutive equations. Practically both experimental and theoretical approaches can be coupled to identify the constitutive equations. Such procedure has been performed for modelling the sintering of compacts obtained by die pressing of a mixture of tungsten carbide and cobalt powders. The constitutive behaviour of this material during sintering has been described by a linear viscous constitutive model, whose functions have been fitted from results of free sintering and sinter-forging experiments. This model has next been introduced in ABAQUS finite element code to simulate the sintering of heterogeneous green compacts of various geometries at constant temperature. Examples of simulations are shown and compared with experiments.

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저고도 무인기 교통관리 체계에서 무인기 비행패턴 분류 및 시뮬레이션 모형 개발 (Study on UAV Flight Patterns and Simulation Modelling for UTM)

  • 정규서;김세연;이금진
    • 한국항행학회논문지
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    • 제22권1호
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    • pp.13-19
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    • 2018
  • 본 논문에서는 저고도 무인기 교통관리 체계에서 운용될 무인기의 사용 용도별로 비행패턴을 분석하였고, 시뮬레이션 모형을 개발하였다. 무인기 비행패턴은 감시형, 선회형, 배송형 패턴으로 분류하였으며, 무인기 사용 용도별로는 농업, 시설 점검, 공공안전 및 보안, 물품 배송으로 총 네 가지 경우를 고려하였다. 또한 저고도 무인기 교통관리 체계에 적용할 공역 운용방식을 검증하기 위한 도구로써 시뮬레이션 모형을 개발하였다. 개발된 시뮬레이션 모형을 감시형 비행패턴에 적용해 보았으며, 그 결과 정해진 입력을 받아 주어진 비행패턴을 그리며 비행하는 것을 확인 및 검증하였다. 본 시뮬레이션 모형은 향후 무인기가 다양한 비행패턴을 그리며 해당 용도에 맞게 안전하고 효율적으로 운항할 수 있는지 검증하는데 사용될 예정이다.

PDA기반의 HRV분석 인터페이스에 대한 시뮬레이션의 재활치료용 생체계측 시스템 모델링의 구현 (Embodiment of living body measure system modelling for rehalititation treatment of simulation for HRV analysis interface of PDA base)

  • 김휘영;최진영;박성준;김진영;박성준;김희제
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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    • pp.2167-2168
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    • 2006
  • Mobilecomputer of offers more fundamental role than role assistance enemy of modem technology equipment and new Information Technology can reconsider, and reconstruct creatively accuracy of physiological concept. That military register symptoms are developed of disease, before far before rehalibitation, of for possibility that can intervene in process that motive change of military register symptoms after rehalibitation. But, that many parameters become analysis target and mathematical settlement and equalization system of noted data of that is huge, same time collection of all datas can lift difficulty etc.. These main weakness puts in structural relation between elements that compose system. Therefore, dynamics research that time urea of systematic adjustment has selected method code Tuesday nerve dynamics enemy who groping of approach that become analysis point is proper and do with recycling bioelectricity signal. Nature model of do living body signal digital analysis chapter as research result could be developed and scientific foundation groping could apply HSS (Hardware-software system) by rehalibitation purpose. Special quality that isdone radish form Tuesday of bioelectricity signal formation furthermore studied, and by the result, fundamental process of bodysignal in do structure circuit form of analog - digital water supply height modelling do can.

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음이온계 약물의 간수송과정에 있어서 대향수송의 약물동력학적 모델링 및 시뮬레이션 (Pharmacokinetic Modelling and Simulation of the Counter-transport in the Hepatic Transport of Organic Anions)

  • 송석길;이준섭;정연복
    • 약학회지
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    • 제49권4호
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    • pp.275-283
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    • 2005
  • The purpose of the present study was to kinetically investigate the carrier-mediated uptake in the hepatic transport of organic anions, and to simulate the 'in vivo counter-transport' phenomena, using kinetic model which was developed in this study. The condition that the mobility of carrier-ligand complex is greater than that of free carrier is not essential for the occurrence of 'counter-transport' phenomenon. To examine the inhibitory effects on the initial uptake of organic anions by the liver, it is necessary to judge whether the true counter-transport mechanism (trans-stimulation) is working or not. Effects of bromophenol blue (BPB) or bromosulfophthalein (BSP) on the plasma disappearance curves of a 1-anilino-8-naphthalene sulfonate (ANS) were then kinetically analyzed based on a flow model, in which the ligand is eliminated only from the peripheral compartment (liver compartment). Moreover, 'in vivo counter-transport' phenomena were simulated based on the perfusion model which incorporated the carrier-mediated transport and the saturable intracellular binding. The 'in vivo counter-transport' phenomena in the hepatic transport of a organic anions were well demonstrated by incorporating the carrier-mediated process. However, the 'in vivo counter-transport' phenomena may be also explained by the enhancement of back diffusion due to the displacement of intracellular binding. In conclusion, one should be more cautious in interpreting data obtained from so-called 'in vivo counter-transport' experiments.

도시의 지표형태학적 특성에 기반한 지면미기후 분석: 기온추정 및 평가 (Surface Micro-Climate Analysis Based on Urban Morphological Characteristics: Temperature Deviation Estimation and Evaluation)

  • 이채연;안승만;김규랑;권혁기;민재식
    • 대기
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    • 제26권3호
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    • pp.445-459
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    • 2016
  • Air temperature deviation (ATD) is one of major indicators to represent spatial distribution of urban heat island (UHI), which is induced from the urbanization. The purpose of this study is to evaluate the accuracy of air temperature deviation about Climate Analysis Seoul (CAS) workbench, which had developed by National Institute Meteorological Science and TU Berlin. Comparison and correlation analysis for CAS ATD including meso-scale air temperature deviation, local-scale air temperature deviation, total air temperature deviation, surface heat flux deviation, cold air production deviation among meso-scale numerical modelling variable in 'Seoul Region', micro-scale numerical modelling in 'Detail Region', and CAS workbench variable using observation data in ground stations. Comparison between night time OBS ATD and CAS ATD show that have most close values. Most of observations ($dT_{max}$ and $dT_{min}$) have highly positive ($dT_{SHP}$, $dT_{CA}$, MD, TD, $f_{BS}$, $f_{US}$, $f_{WS}$, $h_B$) and negative ($f_{VS}$, $f_{TV}$, $h_V$, Z) correlations. However, CAS workbench needs further improvement of both observational framework and analytical framework to resolve the problems; (1) night time OBS ATD of has closer values in compare with at high rise mountain area and (2) correlations are very dependable to meteorological scale.

부정적 정서 유통에 따른 대인관계 문제의 영성효과: 트라우마를 중심으로 (Spirituality's Impact on Posttraumatic Interpersonal Relation Regarding the Distribution of Negative Affect)

  • 이은성;최충익
    • 유통과학연구
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    • 제17권5호
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    • pp.103-111
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    • 2019
  • Purpose - This paper aims to examine a spirituality's impact on the posttraumatic interpersonal relationships of family violence with a structural equation model(SEM). This article starts with the research idea that family violence experience bring about negative emotion in terms of interpersonal relationship leading to the distribution of negative affect in social relationship. The research question of this study pinpoints on how family violence experience affects interpersonal relationship problems and how spirituality affects interpersonal relations problems. Based on the idea, we attempts to deal with spirituality's impact as a driving factor of transforming the distribution of negative affect. Research design, data, and methodology - The structural equation modelling(SEM) is employed as a analysis method of this study. SEM provides a chiefly cross-sectional statistical modelling method, and moreover it allows multiple variables to be associated with a latent variable in this analysis. 300 samples from Seoul, Gyeonggy and Gangwon are selected in the survey. We chose available 271 among them. Results - The results verify that trauma have placed an negative impact on personal relations. The study results also shows that the more serious get the degree of family violence trauma, the worse become interpersonal relationship problems. What is more interesting is that the degree of trauma's impact on interpersonal relation problems in male is higher than that of trauma's impact in female. It is mainly attributed to the fact that women are superior to men in terms of empathy ability and interpersonal relationship orientation. It can be noted that the well-managed spirituality will be able to make a great contribution towards reducing the degree of trauma caused by interpersonal relationships. Conclusions - The study results demonstrates that family violence have negative impacts on spirituality, while spirituality have an positive impacts on reduction the problems of interpersonal relationship. It has been found out that family violence trauma may cause negative affectivity in personal relations, which can distribute negative impacts regarding interpersonal relationship in society. This study also supports that spirituality will be able to function well as a helper, which may reduce the distribution of negative affect in society.

Filtration-induced pressure evolution in permeation grouting

  • Zhou, Zilong;Zang, Haizhi;Wang, Shanyong;Cai, Xin;Du, Xueming
    • Structural Engineering and Mechanics
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    • 제75권5호
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    • pp.571-583
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    • 2020
  • Permeation grouting is of great significance for consolidating geo-materials without disturbing the original geo-structure. To dip into the filtration-induced pressure increment that dominates the grout penetration in permeation grouting, nonlinear filtration coefficients embedded in a convection-filtration model were proposed, in which the volume of cement particles in grout and the deposited particles of skeleton were considered. An experiment was designed to determine the filtration coefficients and verify the model. The filtration coefficients deduced from experimental data were used in simulation, and the modelling results matched well with the experimental ones. The pressure drop revealed in experiments and captured in modelling demonstrated that the surge of inflow pressure lagged behind the stoppage of flow channels. In addition, both the consideration of the particles loss in liquid grout and the number of filtrated particles on pore walls presented an ideal trend in filtration rate, in which the filtration rate first rose rapidly and then reached to a steady plateau. Finally, this observed pressure drop was extended to the grouting design which alters the water to cement (W/C) ratio so as to alleviate the filtration effect. This study offers a novel insight into the filtration behaviour and has a practical meaning to extend penetration distance.

Quality monitoring of complex manufacturing systems on the basis of model driven approach

  • Castano, Fernando;Haber, Rodolfo E.;Mohammed, Wael M.;Nejman, Miroslaw;Villalonga, Alberto;Lastra, Jose L. Martinez
    • Smart Structures and Systems
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    • 제26권4호
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    • pp.495-506
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    • 2020
  • Monitoring of complex processes faces several challenges mainly due to the lack of relevant sensory information or insufficient elaborated decision-making strategies. These challenges motivate researchers to adopt complex data processing and analysis in order to improve the process representation. This paper presents the development and implementation of quality monitoring framework based on a model-driven approach using embedded artificial intelligence strategies. In this work, the strategies are applied to the supervision of a microfabrication process aiming at showing the great performance of the framework in a very complex system in the manufacturing sector. The procedure involves two methods for modelling a representative quality variable, such as surface roughness. Firstly, the hybrid incremental modelling strategy is applied. Secondly, a generalized fuzzy clustering c-means method is developed. Finally, a comparative study of the behavior of the two models for predicting a quality indicator, represented by surface roughness of manufactured components, is presented for specific manufacturing process. The manufactured part used in this study is a critical structural aerospace component. In addition, the validation and testing are performed at laboratory and industrial levels, demonstrating proper real-time operation for non-linear processes with relatively fast dynamics. The results of this study are very promising in terms of computational efficiency and transfer of knowledge to manufacturing industry.