• Title/Summary/Keyword: Cube Model

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A Development of Semi-automatic Trawl-net Surfaces Reconstruction System using Motion Equations and User Interactions (운동 방정식과 사용자 상호작용을 적용한 반자동 트롤 그물 표면 재구축 시스템 개발)

  • Yoon, Joseph;Park, Keon-Kuk;Kwon, Oh-Seok;Kim, Young-Bong
    • Journal of Korea Multimedia Society
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    • v.20 no.8
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    • pp.1447-1455
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    • 2017
  • In a trawl-net simulation, it is very important to process the physical phenomenons resulting from real collisions between a net and fishes. However, because it is very difficult to reconstruct the surface with mass points, many researchers have generally detect the collision using an approximation model employing a sphere, a cube or a cylinder. These approaches occur often result in inaccurate movements of a fish due to the difference between a real-net and a designed-net. So, many systems have manually adjusted a net surface based on actual measurements of mass points. These methods are very inefficient because it needs much times in an adjustment and also causes more incorrect inputs according to a rapid increment in the number of points. Therefore, in this paper, we propose a reconstruction method that it semi-automatically reconstructed trawl-net surfaces using the equation of motion at each mass point in a mass-spring model. To get an easy start in a beginning step of the spread, it enables users to get interactive adjustment on each mass point. We had designed a trawl-net model using geometrical structures of trawl-net and then automatically reconstructed the trawl-net surface using scale-space meshing techniques. Last, we improve the accuracy of reconstructed result by correction user interaction.

The Fatigue Evaluation of Structural Steel Members under Variable-Amplitude Loading (변동하중을 받는 강구조부재의 피로거동 해석)

  • Chang, Dong Il;Kwak, Jong Hyun;Bak, Yong Gol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.8 no.2
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    • pp.167-175
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    • 1988
  • The principle objective of this study is to evaluate the fatigue behavior of structural steel components of highway bridges subjected to service stresses. The main aspects of this investigation are; 1) a measurement and statistical analysis of service stress cycles observed in highway bridge. 2) fatigue tests under equivalent constant-amplitude(CA) loading and simulated variable-amplitude(VA) loading 3) a evaluation of the fatigue behavior under VA-loading by eqivalent root mean cube (RMC) stress range. Theoretically, the RMC model is adequate in evaluation of fatigue behavior under VA-loading, because the regression coefficient (m) of crack growth rate is 3 approximately. The result of fatigue test shows that the RMC model is fitter than the current RMS model in fatigue evaluation under VA-loading. The interaction effects and sequence effects under VA-loading affect little fatigue life of structural components. As the transition rate of stress ranges is higher, the crack growth rate is higher.

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Research of Next Generation IoF-Cloud based Smart Geenhouse & Services (차세대 IoF-Cloud 기반 스마트 온실 및 서비스 연구)

  • Cha, ByungRae;Choi, MyeongSoo;Kim, BongKook;Cheon, OhSeung;Han, TaeHo;Kim, JongWon;Park, Sun
    • Smart Media Journal
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    • v.5 no.3
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    • pp.17-24
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    • 2016
  • Korean agriculture is currently experiencing difficulties as a cause of rural depopulation, aging of rural population, grain self-sufficiency rate decline, and deepening of climate change. It is necessary to ensure our country's agriculture industrial competitiveness in accordance with opening of FTA imports expanded. To ensure the underdeveloped competitive, Korean government defines the 3rd generation model from 1st generation model to extend the smart farms of Korean types. The agriculture smarting overcomes the growth limitations of agriculture, and efforts to develop 6th + ${\alpha}$ industry. In this paper, We define and verify the IoF(Internet of Farming)-Cloud based substantial services about 2rd generation model, and propose a greenhouse of IoF-Cloud testbed.

3D Motion of Objects in an Image Using Vanishing Points (소실점을 이용한 2차원 영상의 물체 변환)

  • 김대원;이동훈;정순기
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.11
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    • pp.621-628
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    • 2003
  • This paper addresses a method of enabling objects in an image to have apparent 3D motion. Many researchers have solved this issue by reconstructing 3D model from several images using image-based modeling techniques, or building a cube-modeled scene from camera calibration using vanishing points. This paper, however, presents the possibility of image-based motion without exact 3D information of scene geometry and camera calibration. The proposed system considers the image plane as a projective plane with respect to a view point and models a 2D frame of a projected 3D object using only lines and points. And a modeled frame refers to its vanishing points as local coordinates when it is transformed.

A Daily Production Planning Method for Improving the Production Linearity of Semiconductor Fabs (반도체 Fab의 생산선형성 향상을 위한 일간생산계획 방법론)

  • Jeong, Keun-Chae;Park, Moon-Won
    • Journal of Korean Institute of Industrial Engineers
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    • v.41 no.3
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    • pp.275-286
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    • 2015
  • In this paper, we propose a practical method for setting up a daily production plan which can operate semiconductor fabrication factories more stably and linearly by determining work in process (WIP) targets and movement targets. We first adjust cycle times of the operations to satisfy the monthly production plan. Second, work in process (WIP) targets are determined to control the production progress of operations: earliness and tardiness. Third, movement targets are determined to reduce cumulated differences between WIP targets and actual WIPs. Finally, the determined movement targets are modified through a simulation model which considers capacities of the equipments and allocations of the WIPs in the fab. The proposed daily production planning method can be easily adapted to the memory semiconductor fabs because the method is very simple and has straightforward logics. Although the proposed method is simple and straightforward, the power of the method is very strong. Results from the shop floor in past few periods showed that the proposed methodology gives a good performance with respect to the productivity, workload balance, and machine utilization. We can expect that the proposed daily production planning method will be used as a useful tool for operating semiconductor fabrication factories more efficiently and effectively.

VLC Channel Model Considering Indirect Light (간접 조명 환경 실내 가시광 통신의 채널 모델)

  • Lee, Jung-Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38C no.8
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    • pp.706-712
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    • 2013
  • In this paper, channel modeling of VLC(Visible Light Communication) was investigated under indirect lightning circumstance which was the way that all phontons started from LED(Light Emitting Diode) were reached on the floor with NLOS paths. I supposed width(6m), depth(4m), height(2.2m) cube room circumstance for VLC communication channel and supposed that 4 LEDs were located at 2m height, which emitted photons at the direction of wall and ceiling. Channel characteristics, which were power attenuation and delayed receiving of light signal, were abstracted from receivers(PDs) which were located at 0.5m above from floor. The availability of channel was verified via BPSK based communication simulation.

Web Information Extraction and Multidimensional Analysis Using XML (XML을 이용한 웹 정보 추출 및 다차원 분석)

  • Park, Byung-Kwon
    • Journal of Korea Multimedia Society
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    • v.11 no.5
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    • pp.567-578
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    • 2008
  • For analyzing a huge amount of web pages available in the Internet, we need to extract the encoded information in web pages. In this paper, we propose a method to extract and convert web information from web pages into XML documents for multidimensional analysis. For extracting information from web pages, we propose two languages: one for describing web information extraction rules based on the object-oriented model, and another for describing regular expressions of HTML tag patterns to search for target information. For multidimensional analysis on XML documents, we propose a method for constructing an XML warehouse and various XML cubes from it like the way we do for relational data. Finally, we show the validness of our method through the application to US patent web pages.

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Uncertainty Analysis of Fire Modeling Input Parameters for Motor Control Center in Switchgear Room of Nuclear Power Plants (원자력발전소 모터제어반 스위치기어실 화재 모델링 입력변수 불확실성 분석)

  • Kang, Dae-Il;Yang, Joon-Eon;Yoo, Seong-Yeon
    • Fire Science and Engineering
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    • v.26 no.2
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    • pp.40-52
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    • 2012
  • This paper presents the uncertainty analysis results of fire modeling input parameters for motor control center in switchgear room of nuclear power plants. FDS (Fire Dynamics simulator) 5.5 was used to simulate the fire scenario and Latin Hyper Cube Monte Carlo simulations were employed to generate random samples for FDS input parameters. The uncertainty analysis results of input parameters are compared with those of the model uncertainty analysis and sensitivity analysis approaches of NUREG-1934. The study results show that the input parameter uncertainty analysis approach may lead to more conservative results than the uncertainty analysis and sensitivity analysis methods of NUREG-1934.

Development of Rendering Techniques for Particle-based Flow Simulation (입자 기반 유동 시뮬레이션의 렌더링 기술 개발)

  • Lee, Byung-Hyuk;Park, Jong-Chun;Jang, Young-Su;Kim, Sang-Hyun
    • Journal of Ocean Engineering and Technology
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    • v.23 no.1
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    • pp.38-42
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    • 2009
  • Recently, various particle based simulation techniques, which solve the Navier Stokes and continuity equations, have been developed and applied to complicated engineering problems. However, although progress is being made on their visualization or rendering techniques, these are still insufficient. In this study, to render a smooth configuration for a free surface, a rendering technique was developed that included the generation of density fields from the location information for simulated particles and the creation model for a polygonal surface. The developed rendering technique was applied to the visualization of a dynamic free surface flow interacting with a structure using a particle based simulation technique.

Analysis of NOx Emissions in Thrbulent Nonpremixed Hydrogen-Air Jet Flames with Coaxial Air (동축 수소 확산화염에서의 NOx 생성 분석)

  • Park, Y.H.;Kim, S.L.;Moon, H.J.;Yoon, Y.B.;Jeung, I.S.
    • Journal of the Korean Society of Combustion
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    • v.5 no.1
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    • pp.19-30
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    • 2000
  • The characteristics of NOx emissions in pure hydrogen nonpremixed flames with coaxial air are analyzed numerically for the three model cases of coaxial air flames classified by varying coaxial air velocity and/or fuel velocity. In coaxial air flames, the flame length is reduced by coaxial air and can be represented as a function of the ratio of coaxial air to fuel velocity. Coaxial air decreases flame reaction zone, resulting in reducing flame residence time significantly. Finally, the large reduction of EINOx is achieved by the decrease of the flame residence time. It is found that because coaxial air can break down the flame self-similarity law, appropriate scaling parameters, which are different from those in the simple jet flames, are recommended. In coaxial air flames, the flame residence time based on the flame volume produces better results than that based on a cube of the flame length. And some portion of deviations from the 1/2 scaling law by coaxial air may be due to the violation of the linear relationship between the flame volume and the flame reaction zone.

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