• Proceedings of the Korea Multimedia Society Conference
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• 1998.10a
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• pp.149-154
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• 1998

본 논문에서는 월드와이드웹상에서 3차원 인터페이스를 기술하는 표준 사양인 VRML과 자바의 EAI(External Authoring Interface)를 통하여 사용자 간에 발생하는 상호작용들을 동기화 시키는 방법을 소개한다. 제시한 방법에서는 별도의 독립적인 응용프로그램을 작성하거나 동기화를 위하여 확장된 VRML을 사용할 필요없이 웹브라우저와 바로 호환하여 사용할 수 있으며 기존의 방대한 웹문서와 연계가 쉬우므로 범용적인 자료구축이 가능하다. 하지만, 가장 최근의 VRML97에서조차도 VRML이 제시하는 가상공간 다중 사용자 환경의 지원은 아직 미비하다. 더 이상 단순히 3차원 월드를 탐험하는 시기는 지났으며, 같은 공간상에서 혼자가 아닌 여럿이 함께 하는 다중 사용자 환경을 제공해야 할 것이다. 이에 자바의 네트웍 기능과 가상공간의 외부에서 동적으로 월드를 제어할 수 있는 EAI를 이용하여 부족했던 다중 사용자 환경을 지원함으로써 가상 공간 시스템을 구축할 수 있다. 그러나, 가상 공간에서 일어나는 이벤트는 단지 동일 브라우저에서만 유효하기 때문에 다른 사용자에게 전달할 때는 이벤트를 원격지의 이벤트와 연동하기 위하여 다른 방법이 필요하다. 사용자 상호작용 시스템에 있어서 이러한 이벤트를 결정하는 가장 중요한 요소는 아바타의 행동양식(avatar's behavior)이라 할 수 있다. 가상 공간에서 일어나는 이벤트의 대부분이 사용자에 의해서 발생되는 것들이다. 즉, 아바타의 행위에 따라서 사용자 서로 간에 상호작용이 일어나게 되며 이들 이벤트를 서로 동기화 함으로써 실시간 3차원 상호작용 시스템을 구현한다. 이렇게 구현된 시스템을 구현한다. 이렇게 구현된 시스템은 전자 상거래, 가상 쇼핑몰, 가상 전시화, 또는 3차원 게임이나 가상교육 시스템과 같은 웹기반 응용프로그램에 사용될 수 있다.물을 보존·관리하는 것이 필요하다. 이는 도서관의 기능만으로는 감당하기 어렵기 때문에 대학정보화의 센터로서의 도서관과 공공기록물 전문 담당자로서의 대학아카이브즈가 함께 하여 대학의 공식적인 직무 관련 업무를 원활하게 지원하고, 그럼으로써 양 기관의 위상을 높이는 상승효과를 낼 수 있다.하여는, 인쇄된 일차적 정보자료의 검색방법등을 개선하고, 나아가서는 법령과 판례정보를 위한 효율적인 시스템을 구축하며, 뿐만 아니라 이용자의 요구에 충분히 대처할 수 잇는 도서관으로 변화되는 것이다. 이와 함께 가장 중요한 것은 법과대학과 사법연수원에서 법학 연구방법에 관한 강좌를 개설하여 각종 법률정보원의 활용 내지 도서관 이용방법에 관하여 교육하는 것이다.글을 연구하고, 그 결과에 의존하여서 우리의 실제의 생활에 사용하는 $\boxDr$한국어사전$\boxUl$등을 만드는 과정에서, 어떤 의미에서 실험되었다고 말할 수가 있는 언어과학의 연구의 결과에 의존하여서 수행되는 철학적인 작업이다. 여기에서는 하나의 철학적인 연구의 시작으로 받아들여지는 이 의미분석의 문제를 반성하여 본다. 것이 필요하다고 사료된다.크기에 의존하며, 또한 이러한 영향은 $(Ti_{1-x}AI_{x})N$ 피막에 존재하는 AI의 함량이 높고, 초기에 증착된 막의 업자 크기가 작을 수록 클 것으로 여겨진다. 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을 확인할수 있지만 엄밀히 생각하여 보면 이러한 예의 경우도 최락의 총체적인 외형은 마찬가지로 $\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$순응

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.225-231
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• 2022

Transcendence of space and time, virtual reality, augmented reality, etc. are being realized through the latest technologies in the era of the 4th industrial revolution. In a situation where they are currently experiencing artificial intelligence, augmented reality, big data, etc., the degree of interest in the latest technologies of the 4th industrial revolution for radiology students, the necessary competencies in the 4th industrial revolution era, and the prospect of the radiation field employment environment in the 4th industrial revolution era The purpose of this study was to find out the level of awareness of From February 7th to February 18th, 2022, surveys on awareness were analyzed using questionnaires for 2nd and 3rd year students in the Department of Radiology at S University in Daegu. As a result of the study, the level of interest in 3D modeling was shown to be the highest with an average of 3.34 ± 1.09 points, and interest in big data and artificial intelligence was also shown with an average of 3.27 ± 1.17 and 3.33 ± 1.07 points. In addition, the correlation between the awareness of the necessary competencies in the 4th industrial revolution era and the awareness of the prospects for employment in the radiation field in the 4th industrial revolution era was the highest (r=0.778, p<0.01), and the interest in the latest technologies in the 4th industrial revolution and the 4th industrial revolution It was found that there was also a correlation between the perceptions of the necessary capabilities of the times (r=0.694, p<0.01). In the era of the 4th industrial revolution, it is judged that it is necessary to strengthen professional education that can handle the latest technologies such as 3D printing, artificial intelligence, and big data, and to strengthen employment capabilities related to the latest technologies in the field of radiation medical technology.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.899-915
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• 2018

In this study, in order to construct an eco-friendly advanced road transportation network, the multi-layer tunnel, which is a small-sized car road, is designed to have a height of less than 60 cm. However, the shape of the tunnel is low and the height of the traffic sign is small. In order to solve these problems, traffic sign characters were designed in three dimensions, and the possibility of applying the design of the three - dimensional sign that can obtain greater visibility than the existing signs at the same distance and the possibility verification through virtual simulation were performed. The three-dimensional sign is horizontally installed on the ceiling of the multi-layer tunnel. To be seen vertically, it is enlarged by a certain ratio by the perspective, and the width and height are enlarged. Respectively. In addition, 3D simulation was performed to verify the visibility of the stereoscopic signs when the driver ran through the stereoscopic sign design specifications. As a result of the design and experimental study, it was confirmed that the stereoscopic sign could be designed through the theoretical formula and that it could provide the driver with a larger traffic sign character because there is no limitation of the facility limit compared to the existing vertical traffic sign. Also, we confirmed that it can be implemented in the side wall by using the stereoscopic sign design principle installed on the ceiling part. It was confirmed that the design of the stereoscopic sign can be designed to be smaller as the distance that the driver visually recognizes the sperm is shorter, the height of the protrusion vertically at the lower part of the stereoscopic sign becomes higher. As a result of 3D simulation running experiment based on the design information of the stereoscopic sign, it was confirmed that the stereoscopic sign is visually the same as the vertical sign at the planned distance. Although the detailed research and institutional improvement of stereoscopic signs have not been made in Korea and abroad, it is evolved into a core technology of new road traffic facilities through various studies through the possibility of designing and applying stereoscopic signs developed through this study Expect.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.1
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• pp.59-76
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• 2020

As a continuous increase in demand for the transportation infrastructure in the metropolitan area, the renovation of existing metropolitan and urban railway lines for the rapid transport system requires the construction of sidetrack that can operate local and express trains simultaneously. However, the construction of sidetrack after stopping the operation of the existing subway line causes a lot of economic losses, therefore it is essential to study the tunnel enlargement scheme during the operation of the existing subway tunnel. Accordingly, in this paper, basic research on the enlargement plan of the existing subway tunnel was carried out for the renovation of the existing subway line. In order to investigate the method for the sidetrack construction, the Government Complex Gwacheon station on the Gwacheon line of subway line 4 was selected as a virtual research station. Subsequently, four construction plans including tunnel cross-sectional plan for each section were reviewed and constructability and economic feasibility were compared. Finally, the stability assessment was conducted for the selected construction plan which was considered to be relatively unstable by 3-D full numerical analysis considering the sidetrack construction process.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.430-436
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• 2018

Special railway vehicles for track maintenance are equipped with a tamping device that adjusts various track trajectories to reduce the vibration of rolling stock and improve ride quality during trains passing over a track. The development of a simulator that can confirm the error of the actual tamping work is important for reducing human error in the linearization of the track misalignment. In this study, to improve the reality and training effect of conventional 2D simulator, 3D simulator modeling was implemented for tamping work of special railway vehicles in virtual space. The problem of buffering during high screen quality of tamping work was solved using the Unwrap UVW mapping technique of a low polygon extracted from high quality polygon modeling. The human error in the training of the tamping work was detected by the principle of circle and square collision when the tamping tyne and the sleeper collided. In addition, vibration of the driving chair was generated at the same time as the collision, and the number of the sleeper strikes is displayed on the simulator exercise screen. Owing to the scattering of railway ballast protruding from the sleepers, which had a serious effect on the safety of the vehicle, the gravel bouncing effect of the tamping unit was applied.

• Tunnel and Underground Space
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• v.29 no.5
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• pp.332-345
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• 2019

Maximum dip vector of individual joint plane, which can be uniquely defined on the hemispherical projection plane, has been established by considering its dip and dip direction. A new stereographic projection method for the rock slope analysis which employs the maximum dip vector can intuitively predict the failure modes of rock slope. Since the maximum dip vector is uniquely projected on the maximum dip point of the great circle, the sliding direction of discontinuity plane can be recognized directly. By utilizing the maximum dip vector of discontinuity both the plane sliding and toppling directions of corresponding blocks can be discerned intuitively. Especially, by allocating the area of high dip maximum dip vector which can form the flanks of sliding block the potentiality for the formation of virtual sliding block has been estimated. Also, the potentiality of forming the triangular-sectioned sliding block has been determined by considering the dip angle of joint plane the dip direction of which is nearly opposite to that of the slope face. Safety factors of the different-shaped blocks of triangular section has been estimated and compared to the safety factor of the most hazardous block of rectangular section. For the wedge analysis the direction of crossline of two intersecting joint planes, which has same attribute of the maximum dip vector, is used so that wedge failures zone can be superimposed on the stereographic projection surface in which plane and toppling failure areas are already lineated. In addition the maximum dip vector zone of wedge top face has been delineated to extract the wedge top face-forming joint planes the orientation of which provides the vital information for the analysis of mechanical behavior of wedge block.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.5
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• pp.245-256
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• 2002

Shadows are important elements in producing a realistic image. Generation of exact shapes and positions of shadows is essential in rendering since it provides users with visual cues on the scene. It is also very important to be able to create soft shadows resulted from area light sources since they increase the visual realism drastically. In spite of their importance. the existing shadow generation algorithms still have some problems in producing realistic shadows in real-time. While image-based rendering techniques can often be effective1y applied to real-time shadow generation, such techniques usually demand so large memory space for storing preprocessed shadow maps. An effective compression method can help in reducing memory requirement, only at the additional decoding costs. In this paper, we propose a new image-barred shadow generation method based on image warping. With this method, it is possible to generate realistic shadows using only small sizes of pre-generated shadow maps, and is easy to extend to soft shadow generation. Our method will be efficiently used for generating realistic scenes in many real-time applications such as 3D games and virtual reality systems.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.4
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• pp.249-256
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• 2022

The implant prosthesis of anterior maxilla requires careful consideration in planning. In order to satisfy both esthetic and functional needs of a patient, fusion of intra-oral scan in Cone-beam computed tomography (CBCT) and facial scan can be considered. Bony structures and soft tissues captured in CBCT and occlusal surfaces of intra oral scan were incorporated into personal characteristics from facial scan. The patient had insufficient buccal bone on maxillary anterior area. The maxillary implants could not be placed on the most ideal position. However, the "top down" approach completed by computer-generated arranging of teeth in implant planning and surgery with surgical guide resulted in esthetically and functionally satisfying result regardless of the limitation. Careful diagnosis with digital technique and the usage of surgical guide resulted in successful surgery and esthetic restoration. The temporary fixed prostheses were designed, restored and evaluated. The patient was not satisfied with the first design of temporary prosthesis, which showed uneven space distribution between teeth due to the position of maxillary implant. The design was modified by changing proximal emergence contours and line angle to alter the perceived since of incisors. The patient was satisfied with the new design of provisional restoration. A digital occlusion analyzer (Arcus Digma II, KaVo, Leutkirch, Germany) was used to measure inherent condylar guidance and anterior guidance of a patient to provide a definitive prosthesis.

• Tunnel and Underground Space
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• v.33 no.4
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• pp.281-298
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• 2023

Continuous research efforts are being devoted to unmanned mobile platforms for lunar exploration. There is an ongoing demand for real-time information processing to accurately determine the positioning and mapping of areas of interest on the lunar surface. To apply deep learning processing and analysis techniques to practical rovers, research on software integration and optimization is imperative. In this study, a foundational investigation has been conducted on real-time analysis of virtual lunar base construction site images, aimed at automatically quantifying spatial information of key objects. This study involved transitioning from an existing region-based object recognition algorithm to a boundary box-based algorithm, thus enhancing object recognition accuracy and inference speed. To facilitate extensive data-based object matching training, the Batch Hard Triplet Mining technique was introduced, and research was conducted to optimize both training and inference processes. Furthermore, an improved software system for object recognition and identical object matching was integrated, accompanied by the development of visualization software for the automatic matching of identical objects within input images. Leveraging satellite simulative captured video data for training objects and moving object-captured video data for inference, training and inference for identical object matching were successfully executed. The outcomes of this research suggest the feasibility of implementing 3D spatial information based on continuous-capture video data of mobile platforms and utilizing it for positioning objects within regions of interest. As a result, these findings are expected to contribute to the integration of an automated on-site system for video-based construction monitoring and control of significant target objects within future lunar base construction sites.