• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.187-189
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• 2003

3D 가상환경 사용자는 목표하는 지역 또는 대상을 찾아내고 이동하기 위해 Navigation 기술을 사용한다. 3D 가상환경 개발 초기 단계에서부터 효과적인 Navigation을 위해서 Navigation Aid에 대한 연구가 꾸준히 진행되어왔으나, 환경 구조의 중요 지점만을 정리한 요약 형태의 정보를 제공하는 방법이 주를 이루고 있다. 본 논문에서는 의미기반의 Navigation을 통해 원하는 지역 또는 대상을 찾아내고 이론 3D 가상환경에서의 이동으로 연결하는 방법을 제안했다. 의미기반의 Navigation Aid는 3D 가상환경 구조와 무관하게 사람들이 생각하는 측면에서의 Navigation을 지원한다. 따라서 Navigation 대상 환경 구조에 익숙지 않은 방문자라도 유용하게 사용할 수 있으며, 환경을 구성하는 객체들의 위치가 자주 변하더라도 사용자에게 동일한 Navigation 환경을 제공하는 장점을 갖는다.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.480-483
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• 2003

3D 가상환경 개발 초기 단계에서부터 효과적인 Navigation 을 위해서 Navigation Aid 에 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 Cognitive Load를 주고 있다. 본 논문에서는 주제를 이동 또는 세분화하는 과정을 통해 원하는 지역 또는 대상을 선별하여 찾아내고 이를 3D 가상환경에서의 이동으로 연결하는 온톨로지 기반의 Navigation Aid 를 제안했다. 따라서 Navigation 대상 환경 구조에 익숙지 않은 방문자라도 유용하게 사용할 수 있으며, 환경을 구성하는 객체들의 위치가 자주 변하더라도 사용자에게 동일한 Navigation 환경을 제공하는 장정을 갖는다.

• Journal of Game and Entertainment
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• v.2 no.1
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• pp.35-44
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• 2006

Objective of this study is to develop a 3D car navigation system that shows the driving direction to a destination through real-time 3-D panoramic views of the route. For the purpose, a new searching process was established to find the optimal driving direction based on the driver's current location and the real-time traffic situation and the TIP (tour into the picture) method was extended to implement a wide virtual environment. A virtual environment was built up by applying the extended TIP method to the panoramic images taken at a constant distance from a real road, and then, displayed 3-D navigation as clear as the real images. The car navigation system developed in this study provides the optimal driving direction and real-time traffic situation using 2-D navigation module and 3D navigation module.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.928-933
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• 2006

This paper aims to build a 2D/3D map navigation that the user can efficiently operate in terms of feeding attribute information after securing 2D/3D space data. This system provides 2D/3D screen navigation that supports variety of operational visual effects and displays the location that the user is retrieving. Also it presents picture information of buildings with higher resolution and URL, name of store, phone number, other related information. Effectiveness of this system is as follows: first, development and distribution of a new technology of 2D/3D spatial database that changes the previous 2D/3D based system concept to the 2D/3D based one. Second, increase of developmental productivity by utilizing the integrated 2D/3D spatial database for developing various interfaces. Finally, it provides security of the preemptive technological position with world class domestic 2D/3D spatial database technologies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1244-1251
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• 2003

In the paper, we develop the ‘Navigation Mechanism’ that can present the 3D space and trace the location in the user's viewpoint. Especially, using this mechanism, VRML tools are used to develop the virtual reality space in the internet. These mechanism can effectively represent the 3D virtual reality space and apply the many 3D related parts like architefure, education, entertainment and so on.

• Journal of the Ergonomics Society of Korea
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• v.23 no.1
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• pp.23-38
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• 2004

This study examines different types of navigation aids when a navigator performs target search tasks in Virtual Environments. The factors manipulated in this study include target information (None/Landmark). navigational difficulty (Easy/Difficult). and map types (None/2D Map/3D Map). Navigation performance was measured by using task completion time and the number of target locations that was remembered by the navigator. In addition, user satisfaction on the navigation aids was also measured by using a 7-point Likert's scale. The results showed that the user satisfaction on the landmark was high when the 3D Map was provided. The task completion time shortened when navigational difficulty was set at "easy." The number of remembered target locations was large when there was no landmark. It was also large with an easy navigation task. or a map (20 or 3D) provided. Guidelines for selecting navigation aids were proposed based on the results.

• Journal of Positioning, Navigation, and Timing
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• v.8 no.4
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• pp.201-208
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• 2019

Numerical integration is necessary for satellite orbit determination and its prediction. The numerical integration algorithm can be divided into single-step and multi-step method. There are lots of single-step and multi-step methods. However, the Runge-Kutta method in single-step and the Adams method in multi-step are generally used in global navigation satellite system (GNSS) satellite orbit. In this study, 4th and 8th order Runge-Kutta methods and various order of Adams-Bashforth-Moulton methods were used for GLObal NAvigation Satellite System (GLONASS) orbit integration using its broadcast ephemeris and these methods were compared with international GNSS service (IGS) final products for 7days. As a result, the RMSE of Runge-Kutta methods were 3.13m and 4th and 8th order Runge-Kutta results were very close and also 3rd to 9th order Adams-Bashforth-Moulton results. About result of computation time, this study showed that 4th order Runge-Kutta was the fastest. However, in case of 8th order Runge-Kutta, it was faster than 14th order Adams-Bashforth-Moulton but slower than 13th order Adams-Bashforth-Moulton in this study.

• Proceedings of the Korea Society of Design Studies Conference
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• 2005.05a
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• pp.130-131
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• 2005

• Journal of Positioning, Navigation, and Timing
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• v.3 no.2
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• pp.53-62
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• 2014

In the guided missile and unmanned vehicle system, the navigation system is one of the most important components. Recently, low-cost effective smart projectiles and guided bomb are being developed using MEMS based navigation system which has high-G, low-cost and small size. In this paper, locally developed MEMS based GPS/INS integrated navigation system will be introduced in comparison with the state of the art of MEMS based navigation system. And technical design and development method is described to satisfy the required performance of GPS receiver, MEMS inertial sensor assembly, navigation computer and software.

• Korean Journal of Computational Design and Engineering
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• v.22 no.1
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• pp.89-99
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• 2017

In order to make a virtual endoscopy system effective for exploring the interior of the 3D model of a human organ, it is necessary to generate an accurate navigation path located inside the 3D model and to obtain consistent camera position and pose estimation along the path. In this paper, we propose an approach to virtual navigation of blood vessels, which makes proper use of orthogonal contours and skeleton curves. The approach generates the orthogonal contours and the skeleton curves from the 3D mesh model and its voxel model, all of which represent the blood vessels. For a navigation zone specified by two nodes on the skeleton curves, it computes the shortest path between the two nodes, estimates the positions and poses of a virtual camera at the nodes in the navigation zone, and interpolates the positions and poses to make the camera move smoothly along the path. In addition to keyboard and mouse input, intuitive hand gestures determined by the Leap Motion SDK are used as user interface for virtual navigation of the blood vessels. The proposed approach provides easy and accurate means for the user to examine the interior of 3D blood vessels without any collisions between the camera and their surface. With a simple user study, we present illustrative examples of applying the approach to 3D mesh models of various blood vessels in order to show its quality and usefulness.