• Title/Summary/Keyword: Change Visualization

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A Study on Aerodynamic Characteristics of Flapping Motion (플래핑 운동의 공기역학적 특성에 관한 연구)

  • Kim Yoon-Joo;Oh Hyun-Taek;Chung Jin Taek;Choi Hang-Cheol;Kim Kwang-Ho
    • Journal of the Korean Society of Visualization
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    • v.3 no.2
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    • pp.63-70
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    • 2005
  • Birds and insects flap their wings to fly in the air and they can change their wing motions to do steering and maneuvering. Therefore, we created various wing motions with the parameters which affected flapping motion and evaluated the aerodynamic characteristics about those cases in this study. As the wing rotational velocity was fast and the rotational timing was advanced, the measured aerodynamic forces showed drastic increase near the end of stroke. The mean lift coefficient was increased until angle of attack of $50^{\circ}$ and showed the maximum value of 1.0. The maximum mean lift to drag ratio took place at angle of attack of $20^{\circ}$. Flow fields were also visualized around the wing using particle image velocimetry (PIV). From the flow visualization, leading-edge vortex was not shed at mid-stroke until angle of attack of $50^{\circ}$. But it was begun to shed at angle of attack of $60^{\circ}$.

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A Study on Position Estimation of Movable Marker for Localization and Environment Visualization (위치인식 및 환경 가시화를 위한 이동 가능한 마커 위치 추정 연구)

  • Yang, Kyon-Mo;Gwak, Dong-Gi;Han, Jong-Boo;Hahm, Jehun;Seo, Kap-Ho
    • The Journal of Korea Robotics Society
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    • v.15 no.4
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    • pp.357-364
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    • 2020
  • Indoor localization using an artificial marker plays a key role for a robot to be used in a service environment. A number of researchers have predefined the positions of markers and attached them to the positions in order to reduce the error of the localization method. However, it is practically impossible to attach a marker to the predetermined position accurately. In order to visualize the position of an object in the environment based on the marker attached to them, it is necessary to consider a change of marker's position or the addition of a marker because of moving the existed object or adding a new object. In this paper, we studied the method to estimate the artificial marker's global position for the visualization of environment. The system calculates the relative distance from a reference marker to others repeatedly to estimate the marker's position. When the marker's position is changed or new markers are added, our system can recognize the changed situation of the markers. To verify the proposed system, we attached 12 markers at regular intervals on the ceiling and compared the estimation result of the proposed method and the actual distance. In addition, we compared the estimation result when changing the position of an existing marker or adding a new marker.

Analysis of the Research on Augmented Reality Using Knowledge Domain Visualization based on Co-Citation Analysis (동시인용분석 기반 지식영역 가시화 기법을 활용한 증강현실 연구 분석)

  • Lee, Jeonghwan;Lee, Jae Yeol
    • Korean Journal of Computational Design and Engineering
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    • v.18 no.5
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    • pp.309-320
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    • 2013
  • Augmented reality (AR) is considered to be an excellent user interface to a 3D information space embedded within physical reality. For this reason, it has been applied to various applications such as design, medical service, interaction, and collaboration. However, there is no formal way of analyzing the research trend and evolution of augmented reality. This paper identifies the research trend and change in augmented reality (AR) via co-citation analysis. The co-citation analysis provides how the AR research has evolved, who are main contributors, and which papers suggest essential and influencing impact. To systematically analyze the cocitation, we have retrieved 1,145 papers from the Web of Science and applied a scientomertric analysis using CiteSpace. Based on the co-citation analysis of authors and documents, it is possible to analyze the evolution of augmented reality, key authors and papers, and breakthroughs. We have also compared the proposed approach with survey papers written by experts so that the result of the co-citation analysis can compromise the qualitative result done by experts, and thus it can provide a different view and insight for visualizing the research on augmented reality.

Flow Characteristics around Archimedes Wind Turbine according to the Change of Angle of Attack (받음각 변화에 따른 아르키메데스 풍력발전 날개 주위의 유동장 변화)

  • Li, Qiang;Kim, Hyun Dong;Ji, Ho Seong;Kim, Kyung Chun
    • Journal of the Korean Society of Visualization
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    • v.11 no.1
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    • pp.28-33
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    • 2013
  • This paper describes aerodynamic characteristics of an Archimedes spiral wind turbine with various angles of attack. The range of angles was controlled from $-30^{\circ}$ (clockwise) to $+30^{\circ}$ (clockwise). The rotating speed of wind turbine at the same angle of attack in both directions was different. The reason why the-maximum rotational speed was observed at $15^{\circ}$ in clockwise direction can be explained based on angular momentum conservation. Quantitative flow visualization around Archimedes wind turbine blade was carried out between $-15^{\circ}$ (clockwise) and $+15^{\circ}$ (counter clockwise) using high resolution PIV method. The relationship between drag force and rotating speeds was discussed. From these results, optimum design on yawing system of Archimedes spiral wind turbine may provide high efficiency on small wind power system.

Visualization of Air Absorption Induced by Free Surface Vortex in the Pump Sump Using Multi-phase Flow Simulation (펌프 섬프장내 자유표면 보텍스에 의한 공기흡입 현상의 가시화)

  • Park, Young-Kyu;Li, Kui. Ming.;Choi, Yoon-Hwan;Lee, Yeon-Won
    • Journal of the Korean Society of Visualization
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    • v.9 no.3
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    • pp.59-64
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    • 2011
  • In this study the change of free surface vortex is expressed through the time volume fraction using multiphase unsteady condition in sump, because in previous studies of the pump sump did not represent the behavior of the free surface vortex exactly due to the reason it was calculated using single phase and steady condition. The reliability of the computational analysis is verified through comparing experimental results with that of present numerical analysis. Homogeneous free surface model is used to apply interactions of air and water. The results show that the free surface vortex can be identified on the isotropic surface at air volume fraction 1%~5%. The vortices make an air column from the free surface to the sump intake and are created and destroyed repeatedly. The behavior of free surface vortex at numerical analysis is quite similar to experimental test. The result of vortex motion according to time, works on a cycle.

Development of a DMU System Operated on a PDM System (PDM 시스템에서 운용되는 DMU 시스템 개발)

  • 이강수;이상헌
    • Korean Journal of Computational Design and Engineering
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    • v.8 no.3
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    • pp.157-166
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    • 2003
  • In this paper, we explain the DMU (digital mockup) system based on the PDM system. Most manufacturing companies are trying to develop a competitive product by increasing the quality, shortening time to market (TIM) and reducing the cost of a product. Some technologies such as SE (System Engineering), CE (Concurrent Engineering), QFD (Quality Function Development), CI (Cost Innovation) and some systems such as CAD (Computer-Aided Design), CAE (Computer-Aided Engineering), CAM (Computer-Aided Manufacturing), PDM (Product Data Management) and visualization system are adopted for these purposes. Specially, DMU system utilizes a visualization system that shows the 3D shape of a product on the computer and it gives a quick intuition to a person whether he/she is an engineer or not. It also can induce the effects of CE and QFD. SO, 0 company is developing a DMU system integrating CAD, visualization and PDM system. The main feature of the developed DMU system is that it is entirely integrated with PDM system, which means that the 3D shape of any part or assembly can be retrieved through PDM system. The DMU system will change the development process, which will increase the competitiveness of a developed product.

Flow Characteristics in a Human Airway model for Oral Cancer Surgery by PIV Experiment and Numerical Simulation (PIV 측정 및 수치해석을 이용한 구강암 수술에 따른 기도 형상 내 유동 특성)

  • Hong, Hyeonji;An, Se Hyeon;Seo, Heerim;Song, Jae Min;Yeom, Eunseop
    • Journal of the Korean Society of Visualization
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    • v.19 no.3
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    • pp.115-122
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    • 2021
  • Oral cancer surgery typically consists of resection of lesion, neck dissection and reconstruction, and it has an impact on the position of hyoid bone. Therefore, morphological change of airway can occur since the geometric parameter of airway is correlated with the hyoid bone. Airflow is affected by geometry of the airway. In this study, flow characteristics were compared between pre- and post-surgery models by both particle image velocimetry (PIV) and numerical simulation. 3D model of upper airway was reconstructed based on CT data. Velocity is accelerated by the reduced channel area, and vortex and recirculation region are observed in pre- and post-surgery models. For the post-surgery model, high pressure distribution is developed by significantly decreased hydraulic diameter, and the longitudinal flow stream is also interrupted.

Preliminary Study on the Factors Analysis of Change Order-Claim in Design-Build Project (설계시공일괄입찰공사의 설계변경 클레임요인 분석에 관한 기초 연구)

  • Ryu, Hyeok-Jun;Park, Byung-Ju;Yoo, Seung-Kyu;Kim, Ju-Hyung;Kim, Jae-Jun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.129-130
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    • 2012
  • Although the order of Design-Build is being expanded by increasing construction scale and demanding hybrid function, the suitable regulation of the contracts is not settled. Design-Build is way by government because there are big construction of much government leading in contract relation high position occupy. So, case that prebendary's claim institution develops by litigation is very rare. But, recently Design-Build is magnified. So, these dispute factors is becoming visualization gradually. The contract system is needed to be consistent by international standard to deal with the problem. This study suggests the useful solutions in detail concerned with the main factor of change order claim by each Design-Build phases through practical sorting and analysis of the causes of Change Order-Claim.

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GIS Based Realistic Weather Radar Data Visualization Technique

  • Jang, Bong-Joo;Lim, Sanghun
    • Journal of Multimedia Information System
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    • v.4 no.1
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    • pp.1-8
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    • 2017
  • In recent years, the quixotic nature and concentration of rainfall due to global climate change has intensified. To monitor localized heavy rainfalls, a reliable disaster monitoring and warning system with advanced remote observation technology and high-precision display is important. In this paper, we propose a GIS-based intuitive and realistic 3D radar data display technique for accurate and detailed weather analysis. The proposed technique performs 3D object modeling of various radar variables along with ray profiles and then displays stereoscopic radar data on detailed geographical locations. Simulation outcomes show that 3D object modeling of weather radar data can be processed in real time and that changes at each moment of rainfall events can be observed three-dimensionally on GIS.

Visualization Study of Dragonfly Type Wing : Reduced Frequency (잠자리 유형 날개의 가시화 연구 : 무차원 진동수)

  • Kim Song Hak;Chang Jo Won
    • 한국가시화정보학회:학술대회논문집
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    • 2004.11a
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    • pp.14-17
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    • 2004
  • A purpose of this visual experiment is to investigate the effect of reduced frequency qualitatively by examining wake pattern change for insect flying motion. Insect is composed of two pair wing with forewing and hindwing, flying motion of insect is performed pitching and plunging so it makes a separation over the wings. The separation affects at the wake pattern and changed wake pattern has an influence on lift, drag and propulsion. This experiment is conducted by using a smoke wire technique and a camera is fixed at hindwing to take a photograph of wake. An electronic device is mounted below test section to find exact the mean positional angle of wing. The reduced frequency in experiment is 0.15, 0.3 and 0.45. We obtained the result which that reduced frequency is closely related to wake pattern that determines flight efficiency.

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