• Title/Summary/Keyword: Modeling step

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Realistic 3-dimensional using computer graphics Expression of Human illustrations (컴퓨터그래픽스를 이용한 사실적인 3D 인물 일러스트레이션의 표현)

  • Kim, Hoon
    • Archives of design research
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    • v.19 no.1 s.63
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    • pp.79-88
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    • 2006
  • A human face figure is a visual symbol of identity. Each different face per person is a critical information differentiating each person from others and it directly relates to individual identity. When we look back human history, historical change of recognition for a face led to the change of expression and communication media and it in turn caused many changes in expressing a face. However, there has not been no time period when people pay attention to a face more than this time. Technically, the advent of computer graphics opened new turning point in expressing human face figure. Especially, a visual image which can be produced, saved, and transferred in digital has no limitation in time and space, and its importance in communication is getting higher and higher. Among those visual image information, a face image in digital is getting more applications. Therefore, 3d (3-dimensional) expression of a face using computer graphics can be easily produced without any professional techniques, just like assembling puzzle parts composed of the shape of each part ands texture map, etc. This study presents a method with which a general visual designer can effectively express 3d type face by studying each producing step of 3d face expression and by visualizing case study based on the above-mentioned study result.

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A Study on DEM-based Automatic Calculation of Earthwork Volume for BIM Application

  • Cho, Sun Il;Lim, Jae Hyoung;Lim, Soo Bong;Yun, Hee Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.2
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    • pp.131-140
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    • 2020
  • Recently the importance of BIM (Building Information Modeling) that enables 3D location-based design and construction work is being highlighted around the world. In Korea, the road map has been established to settle the design based on BIM using drone survey results by 2025. As the first step, BIM would be applied to road construction projects worth more than 50 billion Korean Won from 2020. On the other hand, drone survey regulation has been enacted and the data for drone survey cost were also included on Standard of construction estimate in 2020. However, more careful improvement is required to reflect drone survey results in BIM design and construction. Currently, Engineering instructions and Standard of construction estimate specifies that earthwork volume must be calculated by cross section method only. So it is required to add the method of DEM (Digital Elevation Model) based volume calculation on these regulations to realize BIM application. In order for that, this study verified the method of DEM based earthwork volume calculation. To get an accurate DEM for accurate volume computation, drone survey was carried out according to the drone survey regulation and then could get an accurate DEM data which have errors less than 3cm in X, Y and 6.8cm in H. As each DEM cell has 3D coordinate component, the volume of each cell can be calculated by obtaining the height of area of the cell then total volume is calculated by multiplying total number of cells by volume of each cell for the construction area. Verification for the new calculation method compare with existing method was carried out. The difference between DEM based volume by drone survey and cross section based volume by traditional survey was less than 1.33% and it can be seen that new DEM method will be able to be applied to BIM design and construction instead of cross section method.

Comparison Study on the Performances of NLL and GMM for Estimating Diffusion Processes (NLL과 GMM을 중심으로 한 확산모형 추정법 비교)

  • Kim, Dae-Gyun;Lee, Yoon-Dong
    • The Korean Journal of Applied Statistics
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    • v.24 no.6
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    • pp.1007-1020
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    • 2011
  • Since the research of Black and Scholes (1973), modeling methods using diffusion processes have performed principal roles in financial engineering. In modern financial theories, various types of diffusion processes were suggested and applied in real situations. An estimation of the model parameters is an indispensible step to analyze financial data using diffusion process models. Many estimation methods were suggested and their properties were investigated. This paper reviews the statistical properties of the, Euler approximation method, New Local Linearization(NLL) method, and Generalized Methods of Moment(GMM) that are known as the most practical methods. From the simulation study, we found the NLL and Euler methods performed better than GMM. GMM is frequently used to estimate the parameters because of its simplicity; however this paper shows the performance of GMM is poorer than the Euler approximation method or the NLL method that are even simpler than GMM. This paper shows the performance of the GMM is extremely poor especially when the parameters in diffusion coefficient are to be estimated.

Comparative Analysis for Numerical Modeling of Tidal Current on Geum River Estuary (금강하구 해역에 대한 조류 수치모델링의 비교 해석)

  • Kang, Sung-Jun;Park, Young-Ki
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3583-3589
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    • 2010
  • The semi-implicit scheme proposed by Backhaus is introduced to solve two-dimensional shallow water equation. This mothod is applied for the numerical model solving surface elevation and velocity field of Geum River estuary. For the verification of the method, numerical solutions by this model are compared with ones by Heap's well known explicit model. Solutions of two models resemble each other. The time-step chosen for the semi-implicit scheme turned out to be 3 to 6 times longer than explicit model depending on the stringent CFL criterion. The computation time could be reduced at least 50%. It was proved that this scheme is easy to handle dry banks which can be seen in Geum River estuary and numerical stability is obtained for long time computation.

Health Level 7 Version 3 based Generating Clinical Document Architecture for Medication Administration System (HL7 버전 3 기반의 투약관리시스템을 위한 임상문서구조의 생성)

  • Kim, Genun-Hee;Cho, Su-Mi;Lee, Eun-Joo;Kim, Hwa-Sun;Cho, Hune
    • Journal of Korea Multimedia Society
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    • v.11 no.3
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    • pp.386-397
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    • 2008
  • This study proposes the actualization of a standard data model for activities through the development of clinical document architecture for medication administration using the health level 7 development frameworks(HDF) process based on object oriented analysis and development method of health level 7 V 3. Medication administration is the most common activity performed by clinical professionals at healthcare settings. A standardized information model and structured hospital information system are necessary to achieve evidence-based clinical activities. We had used HDF and various tools(Rose tree, RMIM designer, V3 generator) to create the clinical document architecture(CDA). This allowed us to illustrate each step of the HDF in the administration of medication. This study generated a information model of the medication administration process, which is one clinical activity. It should become a fundamental conceptual model for understanding international standard methodology by information technology(IT) developers with the objective of modeling healthcare information systems.

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Evaluation of Relative Emission of Image Plate by Using Relative Sensitivity in Computed Radiography System (컴퓨터 방사선영상시스템에서 비감도를 이용한 영상판의 상대적 발광량 평가)

  • Seoung, Youl-Hun
    • The Journal of the Korea Contents Association
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    • v.14 no.11
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    • pp.355-361
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    • 2014
  • The aim of the present study was to evaluate a relative emission of image plate (IP) in computed radiography (CR) system by using relative sensitivity in film/screen methods. The characteristic curve was obtained by using the uniform aluminum 11-step wedge penetrometer. X-ray exposure factors on radiographic digital image were 50 kVp, 10 mAs. We adjusted zero of all parameter of algorithms (MUSICA) so proximate to raw data and applied to 200 of exposure class. Modeling on relative emission of IP are used IP without fading time and IP after 4 hours, 8 hours, 12 hours, 24 hours in the respective storage after X-ray exposure. The results of this study showed that the sensitivity point density at the measuring of relative sensitivity in CR was suited pixel values of the 2000 easy to relatively measure the characteristic curve and when relative sensitivity is decreased, the amount of light emitted from the image signal for generating was also decreased. In conclusion, the proposed method of measurement of relative sensitivity can be utilized to evaluate the quantity of relative emission of IP in CR system.

Recent results on the analysis of viscoelastic constitutive equations

  • Kwon, Youngdon
    • Korea-Australia Rheology Journal
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    • v.14 no.1
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    • pp.33-45
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    • 2002
  • Recent results obtained for the port-pom model and the constitutive equations with time-strain separability are examined. The time-strain separability in viscoelastic systems Is not a rule derived from fundamental principles but merely a hypothesis based on experimental phenomena, stress relaxation at long times. The violation of separability in the short-time response just after a step strain is also well understood (Archer, 1999). In constitutive modeling, time-strain separability has been extensively employed because of its theoretical simplicity and practical convenience. Here we present a simple analysis that verifies this hypothesis inevitably incurs mathematical inconsistency in the viewpoint of stability. Employing an asymptotic analysis, we show that both differential and integral constitutive equations based on time-strain separability are either Hadamard-type unstable or dissipative unstable. The conclusion drawn in this study is shown to be applicable to the Doi-Edwards model (with independent alignment approximation). Hence, the Hadamardtype instability of the Doi-Edwards model results from the time-strain separability in its formulation, and its remedy may lie in the transition mechanism from Rouse to reptational relaxation supposed by Doi and Edwards. Recently in order to describe the complex rheological behavior of polymer melts with long side branches like low density polyethylene, new constitutive equations called the port-pom equations have been derived in the integral/differential form and also in the simplifled differential type by McLeish and carson on the basis of the reptation dynamics with simplifled branch structure taken into account. In this study mathematical stability analysis under short and high frequency wave disturbances has been performed for these constitutive equations. It is proved that the differential model is globally Hadamard stable, and the integral model seems stable, as long as the orientation tensor remains positive definite or the smooth strain history in the flow is previously given. However cautious attention has to be paid when one employs the simplified version of the constitutive equations without arm withdrawal, since neglecting the arm withdrawal immediately yields Hadamard instability. In the flow regime of creep shear flow where the applied constant shear stress exceeds the maximum achievable value in the steady flow curves, the constitutive equations exhibit severe instability that the solution possesses strong discontinuity at the moment of change of chain dynamics mechanisms.

Development of a Transportation Demand Analysis Model ${\ulcorner}$AllWayS-Windows Version${\lrcorner}$ (종합 교통수요 예측모형 "사통팔달:윈도우즈"의 개발)

  • Shim, Dae-Young;Cho, Joong-Rae;Kim, Dong-Hyo
    • Journal of Korean Society of Transportation
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    • v.22 no.2 s.73
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    • pp.19-26
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    • 2004
  • AllWayS(AWS, Satongpaldal in Korean) is the first comprehensive computer software in Korea that is developed for the transportation demand modeling. The original DOS version software was recently receded for Windows environment. Traditional 4-step transportation demand forecasting process is incorporated in the software under graphical user interface environment. AWS is able to compose or edit graphic transportation networks data by each scenario which could be the subject of an analysis. Besides, it use database structure that can handle every data of a scenario such as networks, O/D, and socio-economic data, etc. We expect this integrated process could provide each analyst with efficient and easy to use tool for their analysis. Each models in this software is based on traditional algorithms and the results were compared to existing software, EMME/2 and it showed similar results.

A Performance Modeling of the Lean NOx Trap Catalyst with GT-POWERTM (GT-POWERTM를 이용한 Lean NOx Trap 촉매 성능 모델링)

  • Kim, Hyunjun;Han, Manbae;Jeon, Ji-Yong;Kim, Tae-Min
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.6
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    • pp.64-71
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    • 2013
  • In this study we designed a lean $NO_x$ trap (LNT) model with $GT-POWER^{TM}$ program and then the LNT model was compared to the bench flow reactor test results. This model consists of 9 kinetic reactions to represent the main steps of NO oxidation, $NO_x$ adsorption, $NO_x$ release and then its reduction. The comparison was performed on the operating conditions at the space velocity of 50,000 1/hr and 80,000 1/hr with the temperature range of $200^{\circ}C{\sim}500^{\circ}C$ with the even spaced temperature step of $50^{\circ}C$. The experimental results show that the $NO_x$ conversion efficiency was enhanced by the temperature up to $350^{\circ}C$ and then decayed at higher temperatures. The LNT model predicts the similar trend of the $NO_x$ conversion efficiency to the experimental results below $350^{\circ}C$, but overestimates above $350^{\circ}C$. This overestimation comes from the higher reduction efficiency which was obtained by the different reduction gas composition such as $C_3H_6$ in the model to replace $CH_4$, $C_2H_4$ in the bench test.

Calibrating Stereoscopic 3D Position Measurement Systems Using Artificial Neural Nets (3차원 위치측정을 위한 스테레오 카메라 시스템의 인공 신경망을 이용한 보정)

  • Do, Yong-Tae;Lee, Dae-Sik;Yoo, Seog-Hwan
    • Journal of Sensor Science and Technology
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    • v.7 no.6
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    • pp.418-425
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    • 1998
  • Stereo cameras are the most widely used sensing systems for automated machines including robots to interact with their three-dimensional(3D) working environments. The position of a target point in the 3D world coordinates can be measured by the use of stereo cameras and the camera calibration is an important preliminary step for the task. Existing camera calibration techniques can be classified into two large categories - linear and nonlinear techniques. While linear techniques are simple but somewhat inaccurate, the nonlinear ones require a modeling process to compensate for the lens distortion and a rather complicated procedure to solve the nonlinear equations. In this paper, a method employing a neural network for the calibration problem is described for tackling the problems arisen when existing techniques are applied and the results are reported. Particularly, it is shown experimentally that by utilizing the function approximation capability of multi-layer neural networks trained by the back-propagation(BP) algorithm to learn the error pattern of a linear technique, the measurement accuracy can be simply and efficiently increased.

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