• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.274-276
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• 2008

At the stage of content convergence into cell phone, technologies for geo-spatial information sharing and searching are being developed. Currently, 2D portable navigation map for mobile navigation is provided by communication companies, but geobrowers for 3D geo-information in cell phone are under developing. In this study, 3D feature transformation among X3D-M3G-KML, on mobile and web environments, is dealt with as the first stage for the further mobile 3D web application. As well, it is possible to real-time interoperable 3D geo-information exchange issues within both environments.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.4
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• pp.367-378
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• 2020

This paper introduces the development of the iterative multiple signal classification (MUSIC)-based direction-of-arrival (DOA) estimation system using a rotator that can control the direction of antenna for the global navigation satellite system (GNSS) interference. The system calculates the spatial spectrum according to the noise eigenvector of all dimensions to measure the number of signals (NOS). Also, to detect the false peak, the system adjusts the array antenna's direction and checks the change's peak angles. The phase delay and gain correction values for system calibration are calculated in consideration of the chamber's structure and the characteristics of radio waves. The developed system estimated DOAs of interferences located about 1km away. The field test results show that the developed system can estimate the DOA without NOS information and detect the false peak even though the inter-element spacing is longer than the half-wavelength of the interference.

• Journal of the Korea Computer Graphics Society
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• v.18 no.2
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• pp.63-72
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• 2012

As BIM(Building Information Modeling) is widely used in the construction process the need for exploring building models realistically is also growing. In this paper, we present a 3D stereoscopic navigation method for virtual buildings considering virtual perception. We first find out factors that may cause virtual discomfort while navigating stereoscopic building models, and then develop a method for automatically adjusting the range of virtual camera separation. In addition, we measure each user's JND(Just Noticeable Difference) in depth to adjust virtual camera separation and movement. The presented method can be used for various architectural applications by creating user-customized 3D stereoscopic contents.

• Journal of Sensor Science and Technology
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• v.16 no.3
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• pp.220-228
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• 2007

For many applications particularly in navigation system, a three-dimensional representation improves the usability of information. This paper introduces 3D Graphical User Interface (GUI) of indoor location tracking system, 3D Navigation View. The application provides users a 3D visualization of the indoor environments they are exploring, synchronized with the physical world through spatial information obtained from indoor location tracking system. It adopts widely used Virtual Reality Modeling Language (VRML) to construct, represent, distribute and render 3D world of indoor environments over Internet. Java, an all-purpose programming language is integrated to comprehend spatial information received from indoor location tracking system. Both are connected through an interface called External Authoring Interface (EAI) provided by VRML. Via EAI, Java is given the authority to access and manipulate the 3D objects inside the 3D world that facilitates the indication of user's position and viewpoint in the constructed virtual indoor environments periodically.

• Archives of design research
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• v.16 no.3
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• pp.71-80
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• 2003

Virtual Reality fields see the popularization era. Desk-top VR industries are under rapid development, concentrating on various Web VR applications. Performing user navigation in 3D virtual space is a complicate process in which one is looking for a way with understanding logical structures established in a virtual space and noticing established interactions. It is not a process established by a user, but a technical, skillful and conceptual process carefully designed and constructed at the pre-production stage. Therefore, in this paper technical, skillful and conceptual basic theories, related with the interactive navigation in a 3D virtual space, are thoroughly discussed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.341-343
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• 2014

3D 지리정보 통합 플렛폼을 활용하여 해양교통시설 정보 및 이를 운영하기 위한 다양한 부가정보(기상, 낙뢰, 지진, AIS 등)를 매쉬업하여 표출함으로서 해양교통시설을 효과적으로 운영관리하고 이를 활용하여 서비스 이용자 접근성을 보다 표리하게 제공할 수 있는 방안을 제시하고자 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.71-76
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• 2006

With the rapid development of spatial infrastructure in US, Europe, Japan, China and India, there is no doubt that the next generation Global Navigation Satellite System (GNSS) will improve the integrity, accuracy, reliability and availability of the position solution. GNSS is becoming an essential element of personal, commercial and public infrastructure and consequently part of our daily lives. However, the applicability of GPS in supporting a range of location-sensitive applications such as location based services in an urban environment is severely curtailed by the interference of the 3D urban settings. To characterize and gain in-depth understanding of such interferences and to be able to provide location-based optimization alternatives, a high-fidelity 3D urban model of Melbourne CBD built with ArcGIS and large scale high-resolution spatial data sets is used in this study to support a comprehensive simulation of current and future GNSS signal performance, in terms of signal continuity, availability, strength, geometry, positioning accuracy and reliability based on a number of scenarios. The design, structure and major components of the simulator are outlined. Useful time-stamped spatial patterns of the signal performance over the experimental urban area have been revealed which are valuable for supporting location based services applications, such as emergency responses, the optimization of wireless communication infrastructures and vehicle navigation services.

• Journal of Sensor Science and Technology
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• v.16 no.2
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• pp.110-114
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• 2007

In this paper we present 3-D Navigation View, a three-dimensional visualization of indoor environment which serves as an intuitive and unified user interface for our developed indoor location tracking system via Virtual Reality Modeling Language (VRML) in web environment. The extracted user's spatial information from indoor location tracking system was further processed to facilitate the location indication in virtual 3-D indoor environment based on his location in physical world. External Authoring Interface (EAI) provided by VRML enables the integration of interactive 3-D graphics into web and direct communication with the encapsulated Java applet to update position and viewpoint of user periodically in 3-D indoor environment. As any web browser with VRML viewer plug-in is able to run the platform independent 3-D Navigation View, specialized and expensive hardware or software can be disregarded.

• 한국HCI학회:학술대회논문집
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• 2006.02b
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• pp.633-638
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• 2006

We investigated the importance and efficiency of active and passive exploration on the recognition of objects in a variety of virtual environments (VEs). In this study, 54 participants (19 males and 35 females) were randomly allocated into one of two navigation conditions (active and passive navigation). The 3D visual display was presented through HMD and participants used joysticks to navigate VEs. The VEs consisted of exploring four rooms (library, office, lounge, and conference room), each of which had 15 objects. 'Active navigation' was performed by allowing participants to self-pace and control their own navigation within a predetermined time limitation for each room. 'Passive navigation' was conducted by forced navigation of the four rooms in random order. Total navigation duration and objects for both navigations were identical. After navigating VEs, participants were asked to recognize the objects that had been in the four rooms. Recognition for objects was measured by response time and the percentage of correct, false, hit, and miss responses. Those in the active navigation condition had a significantly higher percentage of hit responses (t (52) = 4.000 p < 0.01), and a significantly lower percentage of miss responses (t (52) = -3.763, p < 0.01) in object recognition than those in the passive condition. These results suggest that active navigation plays an important role in spatial cognition as well as providing a better explanation about the efficiency of learning in a 3D-based program.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.421-423
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• 2003

3D 가상환경 개발 초기 단계에서부터 효과적인 Navigation을 위해서 Navigation Aid에 대한 연구가 꾸준히 진행되어왔다. 그러나 지금까지는 환경 구조의 중요 지점만을 정리한 요약 형태의 정보를 제공하는 방법이 주를 이루고 있어서, Navigation 대상 환경에 익숙지 않은 사용자에게 환경구조를 이해하게 하는 인지적 부담을 주고 있다. 본 논문에서는 사용자의 Navigation을 위한 인지적 부담을 최소화 하는 토픽맵을 적용한 투어코스 자동생성 및 생성보조 시스템을 본 Navigation Aid 시스템이 적용된 가상 환경을 통해서 제안했다. 이는 현실세계에 존재하는 환경을 가상환경을 통해 사전방문 하거나 효과적인 이동경로를 선정하는데 도움을 줄 수 있을 것으로 기대한다.