• Steel and Composite Structures
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• 제27권6호
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• pp.717-725
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• 2018

One of the most important design criteria in military tunnels and armoured doors is to resist the blast loads with minimum structural weight. This can be achieved by using steel sandwich panels. In this paper, the nonlinear behaviour of steel sandwich panels, with different core materials: (1) Hollow (no core material); (2) Rigid Polyurethane Foam (RPF); and (3) Vulcanized Rubber (VR) under free air blast loads, was investigated using detailed 3D nonlinear finite element models in Ansys Autodyn. The accuracy of the finite element model proposed was verified using available experimental test data of a similar steel sandwich panel tested. The results show the developed finite element model can be reliably used to simulate the nonlinear behaviour of the steel sandwich panels under free air blast loads. The verified finite element model was used to examine the different parameters of the steel sandwich panel with different core materials. The result shows that the sandwich panel with RPF core material is more efficient than the VR sandwich panel followed by the Hollow sandwich panels. The average maximum displacement of RPF sandwich panel under different ranges of TNT charge (1 kg to 10 kg at a standoff distance of 1 m) is 49% and 53% less than the VR and Hollow sandwich panels, respectively. Detailed empirical design equations were provided to quantify the maximum deformation of the steel sandwich panels with different core materials and core thickness under a different range of blast loads. The developed equations can be used as a guide for engineer to design steel sandwich panels with RPF and VR core material under a different range of free air blast loads.

• Computers and Concrete
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• 제3권1호
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• pp.29-42
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• 2006

In this study, a novel education system for inspection of concrete bridges is presented. The new education approach uses virtual reality (VR) and three-dimensional computer graphics (3DCG) in training engineers to become bridge inspection specialists. The slow time-dependent deterioration of concrete bridges can be reproduced on the computer screen in any chosen time frame, thus providing the trainees with illustrative and educative insight into the deterioration problem. In the proposed VR/3DCG approach a three-dimensional model of concrete bridge, including surfaces, viewpoints and walkthrough paths is created. With the help of this virtual bridge model, an experienced bridge inspection specialist teaches the different deterioration phenomena of concrete bridges to the trainees. The new system was tested, and the inspection results from the case bridge showed that in comparison with the traditional Japanese bridge inspection education system, the new system gives better results. In addition to the improvement of quality of bridge inspections, the new VR/3DCG system-based education brings along some other, more intangible benefits.

• 토지주택연구
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• 제11권3호
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• pp.93-101
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• 2020

Recently, as a BIM-based construction simulation system, 4D CAD tools using virtual reality (VR) objects are being applied in construction project. In such a system, since the expression of the object is based on VR image, it has a sense of separation from the real environment, thus limiting the use of field engineers. For this reason, there are increasing cases of applying augmented reality (AR) technology to reduce the sense of separation from the field and express realistic VR objects. This study attempts to develop a methodology and BIM module for the pre-construction verification system using AR technology to increase the practical utility of VR-based BIM objects. To this end, authors develop an AR-based drawing verification function and drawing object-based 4D model augmentation function that can increase the practical utility of 2D drawings, and verify the applicability of the system by performing case analysis. Since VR object-based image has a problem of low realism to field engineers, the linking technology between AR object and 4D model is expected to contribute to the expansion of the use of 4D CADsystem in the construction project.

• 한국게임학회 논문지
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• 제17권6호
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• pp.19-28
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• 2017

최근 VR(Virtual Reality) 기술을 기반으로 하는 다양한 형태의 가상현실 콘텐츠가 개발되고 있다. 하지만 빠른 속도로 발전하고 있는 가상현실 디바이스 기술에 비해 이러한 디바이스를 적극적으로 활용하는 가상현실 기반 게임 콘텐츠 개발은 부진한 편이다. 본 논문에서는 가상현실 기술을 기반으로 하는 디바이스 중 사용자의 접근성이 높은 HMD(Head Mounted Display) 부착형 모바일 기기를 활용하여 가상현실 노래방을 두 가지 형태의 서로 다른 가상현실 재현방법론(실사기반의 3D 가상현실 공간 생성과 실사기반의 $360^{\circ}$ 영상 방식)으로 개발하고 이에 대한 사용자의 사실감과 몰입감에 대하여 사용자 테스트를 통해 비교 결과를 제시한다. 본 연구진은 논문의 비교 결과가 향후 모바일 기반 가상현실 콘텐츠 개발시 개발 지침으로 활용될 것으로 기대한다.

• 대한조선학회논문집
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• 제55권4호
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• pp.361-369
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• 2018

The ship surveyor makes a scheme of reasonable ship operation by examining whether the ship has been properly constructed in accordance with the rule of classification societies and international conventions or whether the facilities of the ship in operation meet the standard stipulated by law. Even though the ship surveyors of classification society generally consist of people who have the skill of design or operation of a ship, it takes a long time to train a surveyor to the maturity level. This paper describes the development of survey simulator based on virtual ship environment that enables the surveyor minimize trial and errors to survey the ships. By using VR(Virtual Reality) based survey simulator, surveyors possibly achieve improvement of competence in survey quality by means of safe and immersive training environment. In order to improve the usability and utility of the VR simulator, the ship 3D model has been generated using 3D CAD model for design and production in shipyard. Through this, we suggested the possibility of consistent use of 3D model as the digital twin of a ship.

• 한국인터넷방송통신학회논문지
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• 제10권4호
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• pp.83-90
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• 2010

본 논문에서는 촉감 처리기술의 특징인 VR기술과 햅틱디바이스인 Omni를 이용하여 VR공간에서 멀티 터치 포인터에 어류객체의 촉감을 제시하는 모델을 제안하고 가능성을 실험하였다. 본 실험을 위하여 Matlab/Simulink와 Handshake사의 proSENSE Virtual Touch Toolbox을 프로그래밍 툴로 사용하였고, 3D로 모델링 된 물고기 객체들의 자연스런 움직임을 묘사하기 위해 x, y, z축 각각의 움직임을 표현하는데 필요한 함수들을 사용하였다. 이러한 움직임들은 2명의 사용자가 각각 제어하는 멀티 포인트에 사실적인 물리 작용을 제공한다. 실험결과 3D 객체의 외형을 촉감만으로 인지하는 것과 숨 쉬는 상태를 촉감으로 느낄 수 있게 하는 것이 잘 표현되었고, 두 개의 멀티 포인터를 활용함으로 VR공간에서의 다중참여를 통한 게임이나 콘텐츠 개발이 가능함을 확인할 수 있었다.

• 한국자동차공학회논문집
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• 제13권2호
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• pp.149-156
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• 2005

In this paper, the VR(Virtual Reality) simulation system is developed to analyze driver's perceptive response on the ASV(Advanced Safety Vehicle). The ASV is the vehicle of next generation equipped with various warning systems. For the purpose, the VR simulation system consists of VR database, vehicle dynamic model, graphic/sound system, and driving system. The VR database which generates 3D graphic and sound information is organized for the driving reality. Mathematical models of vehicle dynamic analysis are constructed to represent the dynamic behavior of a vehicle. The driving system and the graphic/sound system provide a driver with the operation of a vehicle and the feedback of a driving situation. Also, the real-time simulation algorithm synchronizes the vehicle dynamic model with the VR database. To check the validity of the developed system, a simple scenario is applied to investigate driver's perceptive response time and vehicle acceleration on an emergency situation. It is confirmed that the proposed system is useful and helpful to design the FVCWS(Forward Vehicle Collision Warning System).

• 한국과학교육학회지
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• 제40권2호
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• pp.203-216
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• 2020

본 연구에서는 초등학교 교과 단원 '우리 몸의 소화와 순환'을 주제로 한 가상현실 기반 수업 프로그램의 개발과 적용을 통해 학생들의 인지적·정의적 측면의 향상 효과를 검증하고자 하였다. 이 연구를 위해 서울 소재 초등학교 6학년 105명의 학생을 대상으로 3차시에 걸쳐 가상현실 프로그램을 투입하고 사전 사후 모형 수행 수준 평가지를 수집하였으며, 21명의 학생들의 인터뷰 자료를 통해서 인지적·정의적 효과에 대한 학생들의 인식을 알아보았다. 이에 대한 결과는 다음과 같다. 첫째, 가상현실의 특성을 반영한 VR 프로그램을 개발함으로써 VR 콘텐츠의 학교 수업 적용 가능성을 보였다. 투입된 가상현실 프로그램 자료는 선행연구에 기반을 둔 가상현실 특성인 '조작', '감각화', '상호작용'을 반영하여 개발되었으며, 수업 시간에 프로그램의 이러한 특성들을 반영한 수업 활동을 하였다. 둘째, 가상현실 기반 생물 수업이 학생들의 '공간적 사고', '추상적 사고', 반영적 사고'와 같은 인지적 측면에 효과가 있음을 검증하였다. 인지적인 측면의 효과를 측정하기 위한 분석틀로 '구조', '기능', '시스템 표상화', '시각화', '표지' 요인으로 구성된 과학적 모형 수행 수준 분석틀을 사용하였으며, 모형 수행 수준의 변화를 비교한 결과 모든 영역에서 실험집단과 통제집단의 유의미한 차이가 있었다. 또한 학생들의 인터뷰를 통해서 어떤 가상현실의 특성이 반영되어 인지적 효과에 영향을 주었는지에 대한 학생들의 인식을 알아보았다. 셋째, 가상현실 기반 생물 수업이 '행위유발성', '현존감', '몰입감'을 높임으로써 정의적 측면에 효과가 있음을 인터뷰 자료를 통해서 확인하였다. 본 연구는 향후 가상현실 기반 생물 수업이 교실에 효과적으로 적용될 방향을 제시하는 데 기여할 것으로 기대된다.

• 한국자동차공학회논문집
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• 제12권4호
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• pp.163-172
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• 2004

Nowadays, to analyze the dynamic characteristics of the automotive driving system, the computer simulation linked up with VR(Virtual Reality) technology is treated as the useful method with the improvement of computing ability. In this paper, the VR simulation system has been developed to investigate the driving characteristics of the ASV(Advanced Safety Vehicle) equipped with an ACC(Adaptive Cruise Control) system. For the purpose, VR environment which generates 3D graphic and sound information of the vehicle, the road, the facilities, and the terrain has been organized for the driving reality. Mathematical models of vehicle dynamic analysis including the ACC model have been constructed for computer simulation. The ACC modulates the throttle and brake functions to regulate the vehicle speed so that vehicles could keep proper spacing. Also, the real-time simulation algorithm synchronizes vehicle dynamic simulation with the graphic rendering. With the developed VR simulation system, simple scenarios are applied to analyze the dynamic characteristics. It is shown that the VR simulation system could be useful to evaluate the adaptive cruise controlled vehicle on various driving conditions.

• 대한안전경영과학회지
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• 제1권1호
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• pp.207-216
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• 1999

Too many big accidents have been occurring in Korea during '90. Those were accidents of Sung-Soo Bridge in 1994 and Sam-Poong Department Store in 1995. It was confirmed that the causes of the accident were unreliable construction or building. Therefore, in this study are to use technique of virtual reality(VR) simulation in order to prevent construction accidents. To set up the VR in safety construction, Date Base of variables, VR model and expert system are needed. This system is to build expert system, to visualize of the VR system and navigation, and to find out design errors of construction. Therefore, the purpose of this was to analyze accident type of construction, and apply VR system for simulation technique.