• ETRI Journal
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• v.32 no.6
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• pp.891-900
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• 2010

In this paper, a map-matching (MM) algorithm which combines an estimated position with digital road data is proposed. The presented algorithm using a virtual track is appropriate for a MEMS-based pedestrian dead reckoning (PDR) system, which can be used in mobile devices. Most of the previous MM algorithms are for car navigation systems and GPS-based navigation system, so existing MM algorithms are not appropriate for the pure DR-based pedestrian navigation system. The biggest problem of previous MM algorithms is that they cannot determine the correct road segment (link) due to the DR characteristics. In DR-based navigation system, the current position is propagated from the previous estimated position. This means that the MM result can be placed on a wrong link when MM algorithm fails to decide the correct link at once. It is a critical problem. Previous algorithms never overcome this problem because they did not consider pure DR characteristics. The MM algorithm using the virtual track is proposed to overcome this problem with improved accuracy. Performance of the proposed MM algorithm was verified by experiments.

• Progress in Medical Physics
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• v.13 no.1
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• pp.32-36
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• 2002

For Intensity Modulated Radiation Therapy(IMRT), the spatial resolution of intensity map(IM) is limited by the width of multi-leaf collimator, which would make an effect on the conformity of the target, as well as organs at risk. Several Methods are suggested to increase the spatial resolution, which can be categorized by the hardware-dependent technique and the software-based technique. However the best solution might be to make the width of MLC finer. it has several obstacles in the respects of technical difficulty and cost. This preliminary study is designed to investigate the clinical effectiveness of the virtual-micro IMRT(VMIMRT) technique, one of the software-based technique. A particular intensity map was created, which has 42$\times$54 pixel dimension ,0.5cm pixel size and 15 intensity levels. Using this intensity map, segment fields of IMRT were generated with 1$\times$lcm, 0.5$\times$1cm, 0.5$\times$0.5cm(VMIM) beamlet size, respectively As results, we found that there was no evidence of improvement for VMIMRT, compared with the 0.5$\times$lcm beamlet size which can be delivered by 1cm width MLC. The reason seems to be due to the constraint of VMIMRT. Further study is required to prove the benefit of the VIMRT in clinical case like head and neck cancer, where is expected that higher resolution than 1cm is necessary.

• Journal of Broadcast Engineering
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• v.14 no.5
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• pp.601-615
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• 2009

This paper proposes an efficient depth-map coding method for generating virtual-view images in 3D-Video. Virtual-view images can be generated by the view-interpolation based on the depth-map of the image. A conventional video coding method such as H.264 has been used. However, a conventional video coding method does not consider the image characteristics of the depth-map. Therefore, this paper proposes an adaptive depth-map coding method that can select between the H.264/AVC coding scheme and the proposed gray-coded bit plane-based coding scheme in a unit of block. This improves the coding efficiency of the depth-map data. Simulation results show that the proposed method, in comparison with the H.264/AVC coding scheme, improves the average BD-rate savings by 7.43% and the average BD-PSNR gains by 0.5dB. It also improves the subjective picture quality of synthesized virtual-view images using decoded depth-maps.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.658-660
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• 2017

가상현실은 실감형 콘텐츠를 제작하는 대표적인 분야로 교육, 엔터테인먼트, 의료, 국방, 항공 등 다양한 분야에서 활용할 수 있는 가능성을 보여주고 있어 주목을 받고 있다. 가상현실을 이용한 예술전시는 디지털 미디어를 극대화한 형태라 할 수 있어 최근에 가상현실 전시회로써 다양한 콘텐츠의 구현이 가능하다. 본 연구는 관람객에게 HMD를 이용한 미디어 가상전시를 경험하게 하고 작가의 의도와 보여주고자 하는 시나리오의 의미가 잘 전달될 수 있도록 하는 방법론을 제안한다. 제안한 방법에 의해 콘텐츠를 개발하는데 있어 체험의 몰입도를 높이기 위해 실제 크기의 3D 모델링을 진행하였고, 범프맵(bump map), 노말맵(normal map)과 큰 해상도의 텍스쳐를 제작하여 사용함으로 대중(관람객들)에게 하여금 현실의 오브젝트와 차이점을 느끼지 못하도록 구현 한다.

• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.1
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• pp.1-9
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• 2017

The scale of disaster and damage witnessed in the 2004 Indian Ocean Tsunami and the 2011 Great East Japan Tsunami has motivated researchers in developing foolproof disaster mitigation techniques for safety of coastal communities. This study focuses on developing tsunami hazard map by numerical modeling at Imwon Port to minimize losses of human beings and property damage when a real tsunami event occurs. A hazard map is developed based on inundation maps obtained by numerical modeling of 3 past and 11 virtual tsunami cases. The linear shallow-water equations with manipulation of frequency dispersion and the non-linear shallow-water equations are employed to obtain inundation maps. The inundation map gives the maximum extent of expected flooded area and corresponding inundation depths which helps in identifying vulnerable areas for unexpected tsunami attacks. The information can be used for planning and developing safety zones and evacuation structures to minimize damage in case of real tsunami events.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.831-838
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• 2011

Computer vision research area, a division of computer graphics application area that creates realistic visualization in computer, conducts vigorously researches on developing realistic 3D model or virtual environment. As the popularization and development of 3D display makes common users easy to experience a solid 3D virtual reality, the demand for virtual reality contents are increasing. This paper proposes 3D panorama system using depth point location-based depth map generation method. 3D panorama using depth map gives an effect that makes users feel staying at real place and looking around nearby circumstances. Also, 3D panorama gives free sight point for both nearby object and remote one and provides solid 3D video.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.9
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• pp.1245-1248
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• 2020

Elderly people living alone need smart care for independent living. Recent advances in artificial intelligence have allowed for easier interaction by a computer-controlled virtual human. This technology can realize services such as medicine intake guide for the elderly living alone. In this paper, we suggest an intelligent virtual human and present our virtual human toolkit for controlling virtual humans for a senior citizen living alone. To make the virtual human motion, we suggest our authoring toolkit to map gestures, emotions, voices of virtual humans. The toolkit configured to create virtual human interactions allows the response of a suitable virtual human with facial expressions, gestures, and voice.

• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.819-826
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• 2002

The mobile vector map services for mobile devices, specially for PDA, are being popularized with the advent of KVM (Kilobytes Virtual Machine). However, the services for cellular phone have some problems for implementation, which are the restrictions of bandwidth, resource of the phone, etc. Thus, these restrictions force to develop new map database exclusively for cellular phone services. But, this approach needs high costs and could not support multi user view for a same area. Therefore, we suggest new client/server system for mobile vector map services, using existing general map database, and design and implement the system. The suggested system, which has minimized functions at client and processes map simplification works at sever, makes it possible to serve mobile vector map without developing new map database only for cellular phone.

• Korean Journal of Computational Design and Engineering
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• v.19 no.3
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• pp.272-280
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• 2014

Most of the car navigation systems pzrovide 2D or 3D virtual map-based driving guidance. One of the important issues is how to reduce cognitive burden to the driver who should interpret the abstracted information to real world driving information. Recently, an augmented reality (AR)-based navigation is considered as a new way to reduce cognitive workload by superimposing guidance information into the real world scene captured by the camera. In particular, head-up display (HUD) is popular to implement AR navigation. However, HUD is too expensive to be set up in most cars so that the HUD-based AR navigation is currently unrealistic for navigational assistance. Meanwhile, smartphones with advanced computing capability and various sensors are popularized and also provide navigational assistance. This paper presents a research on cognitive effect and responsiveness of an AR navigation by a comparative study with a conventional virtual map-based navigation on the same smartphone. This paper experimented both quantitative and qualitative studies to compare cognitive workload and responsiveness, respectively. The number of eye gazing at the navigation system is used to measure the cognitive effect. In addition, questionnaires are used for qualitative analysis of the responsiveness.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.544-546
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• 2011

The popularization and development of 3D display makes common users easy to experience a solid 3D virtual reality, the demand for virtual reality contents are increasing. This paper proposes VR panorama system using vanishing point location-based depth map generation method. VR panorama using depth map gives an effect that makes users feel staying at real place and looking around nearby circumstances.