• Journal of Korea Game Society
• /
• v.4 no.3
• /
• pp.11-20
• /
• 2004

Virtual reality that we have seen from the movies in 80's and 90's is hawing near based on the rapid progress of science together with a computer technology. Various virtual reality system developments (such as VRML, HMD FishTank, Wall Type, CAVE Type, and so on) and the advancement of those systems make for the embodiment of virtual reality that gives more sense of the real. Virtual reality is so immersive that makes people feel like they are in that environment and enable them to manipulate without experiencing the environment at first hand that is hard to experience in reality. Virtual reality can be applied to the spheres, such as education, high-level programming, remote control, surface exploration of the remote satellite, analysis of exploration data, scientific visualization, and so on. For some connote examples, there are training of a tank and an aeroplane operation, fumiture layout design, surgical operation practice, game, and so on. In these virtual reality systems, the actual operation of the human participant and virtual workspace are connected each other to the hardware that stimulates the five senses adequately to lend the sense of the immersion. There are still long way to go, however, before long it will be possible to have the same feeling in the virtual reality as human being can have by further study and effort. In this thesis, the basic definition, the general idea, and the kind of virtual reality were discussed. Especially, CAVE typed in reality that is highly immersive was analyzed in definition, and then the method of VR programming and modeling in the virtual reality system were suggested by showing the restoration process of Kyongbok Palace (as the content of the original form of the culture) that was made by KISTI(Korea Institute of Science and Technology Information) in 2003 through design process in virtual reality system. Through these processes, utilization of the immersive virtual reality system was discussed and how to take advantage of this CAVE typed virtual reality system at the moment was studied. In closing the problems that had been exposed in the process of the restoration of the cultural property were described and the utilization plan of the virtual reality system was suggested.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2002.11a
• /
• pp.109-113
• /
• 2002

본 연구에서는 서로 다른 형태의 VR 디스플레이 장비인 가상워크벤치와 프로젝션 월을 연동한 이종협업 가상환경을 구축하고 이러한 환경에서 단일 빌딩을 모델링 하는 전과정을 입체적으로 시뮬레이션 할 수 있는 어플리케이션에 대하여 소개한다. 수평 형태의 가상워크벤치 상에서는 건축가와 일반 사용자 혹은 견습 디자이너가 함께 참여하여 빌딩의 형태 및 색상, 재질 등을 인터랙티브하게 변화시키면서 디자인 된 모델을 단계별로 입체 시뮬레이션 할 수 있도록 하였다. 대형의 스크린을 기반으로 하는 수직형 프로젝션 월에서는 디자인 된 빌딩의 입면도를 시뮬레이션하고 빌딩의 외부 및 주변 환경을 네비게이션 할 수 있도록 하여 동일한 모델을 서로 다른 시점에서 관찰하고 의견을 교환하여 이를 모델링에 반영할 수 있도록 하였다.

• Korean Institute of Interior Design Journal
• /
• v.20 no.5
• /
• pp.160-169
• /
• 2011

In Korea, the construction company has provided houses through apartment sales system. Residents have obtained a variety of information about their future house by visiting a sample house called "the model house" before they purchase home. Advanced technology such as web-based VOD or Virtual Model in recent years has gradually replaced those built environment. In 2009, the Ministry of Land, Transport and Maritime Affairs announced the restraint to the construction of sample houses. Instead, they highly recommended a Virtual Model House as an alternative solution. This study aimed to propose how to design the user-oriented virtual model house through the experiment and survey research. The 3D virtual model house of 85m$^2$ apartment was built and presented by two types (Type A: Bird's Eye View, Type B: Walk through View) on the web page. The subjects evaluated presence, spatial perception and cognition, and usability of each type after exploring them. The results are as follows. (1) The subjects' evaluation of presence showed Type B has more negative effects than Type A such as feeling dizzy or tired even if their values were not so high. (2) The subjects perceived and cognized both types of virtual model house more realistic for the expression of volume of space, the size of opening, and the arrangement of furniture than that of wall finishes and materials. (3) The usability of Type A was significantly higher than that of Type B.

• Fire Science and Engineering
• /
• v.26 no.6
• /
• pp.31-37
• /
• 2012

In this study, the fire risk of the curtain wall structure was compared with a general structure among the double envelope structure using a fire simulation program. To this end, a fire-story building curtain wall was modeled as virtual using the PyroSim based on a fire simulation program (FDS). And then, the fires occurred in the model, divided by curtain wall non-applied model and applied model, in the same structure and place. To identify the fire characteristics, smoke behavior characteristics, viewing distance, and volume fractions of CO and $CO_2$ were comparative analyzed. As a result, it was identified that the curtain wall applied model quickly filled with smoke from the top floor to under the floor compared to the curtain wall non-applied model. From this study, the fire risk of curtain wall structure was evaluated in detail using the fire simulations.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.6A
• /
• pp.411-418
• /
• 2012

In this study, behavior of unpatched and patched cylindrical shells with through-wall cracks has been estimated using numerical experiments, and patching effect of them has been investigated according to various patching parameters. To show credibility of numerical models considered, two ways such as h- and p-methods have been adopted. Also, domain integral method and virtual crack extension method have been considered to calculate energy release rates based on linear elastic fracture mechanics. For examples, the unpatched cylindrical shells with circumferential cracks under remote tension have firstly been analyzed to show the validity of finite element modeling with h-method or p-method, and then the results have been compared with literature values published. Next, the sensitive analysis of patch repaired problems in terms of thickness of patch and adhesive, shear modulus of adhesive, composite material type of patch, crack length, etc. has been carried out.

• Structural Engineering and Mechanics
• /
• v.55 no.5
• /
• pp.1037-1053
• /
• 2015

This paper presents finite element (FE) based pushover analysis of a reinforced concrete structure with a two-leaf cavity wall (TLCW) to estimate the performance level of this structure. In addition to this, an unreinforced masonry (URM) model was selected for comparison. Simulations and analyses of these structures were performed using the DIANA FE program. The mentioned structures were selected as two storeys and two bays. The dimensions of the structures were scaled 1:1.5 according to the Cauchy Froude similitude law. A shake table experiment was implemented on the reinforced concrete structure with the two-leaf cavity wall (TLCW) at the National Civil Engineering Laboratory (LNEC) in Lisbon, Portugal. The model that simulates URM was not experimentally studied. This structure was modelled in the same manner as the TLCW. The purpose of this virtual model is to compare the respective performances. Two nonlinear analyses were performed and compared with the experimental test results. These analyses were carried out in two phases. The research addresses first the analysis of a structure with only reinforced concrete elements, and secondly the analysis of the same structure with reinforced concrete elements and infill walls. Both researches consider static loading and pushover analysis. The experimental pushover curve was plotted by the envelope of the experimental curve obtained on the basis of the shake table records. Crack patterns, failure modes and performance curves were plotted for both models. Finally, results were evaluated on the basis of the current regulation ASCE/SEI 41-06.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.15 no.1
• /
• pp.285-291
• /
• 1991

A two-stage slit type virtual impactor based on the concept of the single stage virtual impactor has been designed, fabricated, and evaluated for the purpose of concentrating the suspended particles in the air with the size range of 1.8-4.5 .mu.m and handling large flow volume. Monodisperse methylene blue particles have been generated with vibrating orifice aerosol generator (VOAG). The separation efficiency and concentration efficiency have been measured by the UV-visible absorption spectrometry. Previous study for a single stage virtual impactor were used to determine the design parameters such as 50% cut-off sizes and dimensions of the two stage virtual impactor. The separation efficiency curve and 50% cut-off Stokes number(cut-off sizes) are not sensitive to the nozzle Reynolds number, but sensitive to the ratio between the minor flow rate and the total flow rate, The measured concentration efficiency was compared with the maximum concentration efficiency determined by the separation efficiencies of the first and the second stages. The differences between the measured and the maximum concentration efficiencies result from the wall loss due to the deposited particles on the internal walls inside the impactor.

• Korean Journal of Computational Design and Engineering
• /
• v.15 no.3
• /
• pp.167-177
• /
• 2010

In recent years, the use of high-resolution tiled display system which does not have restrictions on the size of the screen and implements various layout of tile is increasing in order to evaluate the digital mock-up in physical scale or explore large engineering data set in detail. In this study, we developed multi-channel distributed visualization system which provides a virtual reality-based visual contents using 3D open-source graphics engine. Efficient data structures and exchange methods were proposed as a scene synchronization technology in PC cluster environments. DLP-Cube based tiled visualization system which provides $5{\times}2$ layout of display wall was developed and we validated our approach using this system. In addition, we introduced integrated control program that administrates PC cluster environment in remote and controls the layout of display channels.

• Proceedings of the Korean Information Science Society Conference
• /
• 2002.04b
• /
• pp.586-588
• /
• 2002

본 논문에서는 반몰입 가상현실 장비인 프로젝션 월(projection wall)가 가상 워크벤치(virtual workbench) 시스템에 적응 가능한 카메라 트래킹 방법 을 제안한다. 제안하는 방법은 측량학에서 거리를 측정하기 위해 사용되어지는 삼각측량법(triangulation)이다. 이 방법은 스테레오 영상을 얻기 위해 사용되는 두 대의 카메라의 기종이 상이할 경우에도 적용이 가능하다는 장점이 있다. 또한, 넓은 트래킹 영역을 확보할 수 있기 때문에 프로젝션 월과 같은 수직형 스크린에 용할 경우 더욱 적합하다. 그리고, 본 논문에서는 신시간 드래킹 글 수행하기 위하여 변화 벡터(shift vector) 기반 위치 추정 방법을 도입하여 검색 시간을 단축시켰으며, 사용자 헤드 드래킹를 수행하기 위해 적외선 비컨을 서텨 글래스(shutter glass)에 부착하여 사용하였다.

• Journal of the Korea Computer Industry Society
• /
• v.5 no.2
• /
• pp.217-226
• /
• 2004

This paper proposes the electric stimulus tactile apparatus system(TESTAS) loaded on the haptic interface using ultrasonic motors (USMs) To touch the virtual object like wall in graphic, the 6 DOF haptic interface provides force feedback to users as if it is real. But the case of sharp virtual object like a puncture, it could not provided the sense of pain, but only the reaction-force. After the TESTAS had been loaded on this haptic interface, it could provide not only the force but also the pain to users. In this way, when users take the haptic and tactile informations at the same time, they easily have a correct understanding of virtual object.