• Korean Journal of Remote Sensing
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• v.22 no.5
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• pp.351-356
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• 2006

Based on current practical needs for geo-spatial information on mobile platform, the main theme of this study is a design and implementation of dynamic 3D terrain rendering system using spaceborne imagery, as a kind of texture image for photo-realistic 3D scene generation on mobile environment. Image processing and 3D graphic techniques and algorithms, such as TIN-based vertex generation with regular spacing elevation data for generating 3D terrain surface, image tiling and image-vertex texturing in order to resolve limited resource of mobile devices, were applied and implemented by using graphic pipeline of OpenGL|ES (Embedded System) API. Through this implementation and its tested results with actual data sets of DEM and satellite imagery, we demonstrated the realizable possibility and adaptation of complex typed and large sized 3D geo-spatial information in mobile devices. This prototype system can be used to mobile 3D applications with DEM and satellite imagery in near future.

• The Journal of Korea Robotics Society
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• v.4 no.1
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• pp.74-80
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• 2009

This paper presents a remote monitoring and simulation system for a building cleaning mobile robot. It provides a tool of convenient 3D graphical map construction including network camera image viewer and status information of the robot. The 3D map is reconstructed from existing 2D building CAD data with DXF format using OpenGL graphic API. Through this system, it is possible to monitor and control the cleaning mobile robot from remote place. A practical experiment is performed to show the reliability and convenience of the monitoring system. The proposed system is expected to give efficient way of control and monitoring to building cleaning mobile robot.

• Journal of Korea Multimedia Society
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• v.22 no.8
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• pp.897-912
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• 2019

The growth of domestic fashion industry market went sluggish affected by long-term slow growth and shrinking consumer sentiment since 2012, and the entire market has shown a slight growth since 2017. Yet only some conglomerates or global businesses experience this growth. Small and medium-sized fashion companies or rising fashion designers in South Korea, face real limitations and problems poor capital, lack of professional workforce, experience, information and educational opportunity as well as difficulty of acquiring distribution network, which lead to further polarization between conglomerates and small businesses. Thus, this study proposed mobile virtual viewer system-based collaborative application prototype capable of overcoming limitations and problems drawn by analyzing business environment of domestic brands launched by rising fashion designers. Especially, through applied template-based 3D virtual fashion design technology and performing the entire process in the virtual reality beyond spatial and temporal restraints, it is assumed that more effective and efficient outcomes can be obtained compared to the previous method.

• Korean Journal of Computational Design and Engineering
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• v.18 no.4
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• pp.258-266
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• 2013

In shipbuilding, 2D manufacturing drawings are crucial for building a ship. Even various types of 3D models are being utilized for supporting ship manufacturing, which does not reduce the importance of 2D drawings. Recently things are changing in the shipbuilding industry. To reduce the number of 2D drawings or to reduce the quantity of information contained in 2D drawings, some attempts that can substitute for 2D drawings are being made. One of the attempts is to visualize lightweight 3D manufacturing models in a mobile device. In this paper, a method for displaying lightweight 3D models of a ship in an Android based device is introduced. To overcome the problem with parsing JT files in Android system, JT files are parsed in a Windows based server and as-simple-as-possible visualization data are transmitted to an Android based viewer. A comparison result with a commercial system is also given.

• Korean Journal of Computational Design and Engineering
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• v.12 no.6
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• pp.413-421
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• 2007

3D rendering is becoming a common feature of mobile application programs with the rapid advance of mobile devices. Since the existing rendering engines do not provide triangulation functions, mobile 3D programs have focused on an efficient handling with pre-tessellated geometry. In addition, triangulation is comparatively expensive in computation, so it seems that the triangulation cannot be easily implemented on mobile devices with limited resources. Triangulation of 3D geometry is the essential process of visualization of 3D model data and many different triangulation methods have been reported. We developed a light and fast visualization process that involves constrained triangulation based on Voronoi diagram and applied it to a mobile computer application. In this paper, we applied kd-tree to the original incremental construction algorithm and produced new O(nlogn) incremental construction algorithm. And we show a simple and efficient constrained triangulation method based on Voronoi diagram. This paper also describes an implementation of mobile STEP data viewer as an application of our proposed algorithms.

• Journal of Information Processing Systems
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• v.12 no.4
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• pp.612-630
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• 2016

As mobile augmented reality technologies are spreading these days, many users want to produce augmented reality (AR) contents what they need by themselves. To keep pace with such needs, we have developed a mobile AR contents builder (hereafter referred to as MARB) that enables the user to easily connect a natural marker and a virtual object with various interaction events that are used to manipulate the virtual object in a mobile environment so that users can simply produce an AR content using natural photos and virtual objects that they select. MARB consists of five major modules-target manger, virtual object manager, AR accessory manager, AR content manager, and AR viewer. The target manager, virtual object manager and AR accessory manager register and manage natural target markers, various virtual objects and content accessories (such as various decorating images), respectively. The AR content manger defines a connection between a target and a virtual object with enabling various interactions for the desired functions such as translation/rotation/scaling of the virtual object, playing of a music, etc. AR viewer augments various virtual objects (such as 2D images, 3D models and video clips) on the pertinent target. MARB has been developed in a mobile application (app) format in order to create AR contents simply using mobile smart devices without switching to a PC environment for authoring the content. In this paper, we present the detail organizations and applications of MARB. It is expected that MARB will enable ordinary users to produce diverse mobile AR contents for various purposes with ease and contribute to expanding the mobile AR market based on spread of a variety of AR contents.

• Journal of the Korea Computer Graphics Society
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• v.19 no.1
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• pp.11-20
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• 2013

This paper introduces a user interface for large 3D meshes in mobile systems, which have limited memory, screen size and battery power. A large 3D mesh is divided into partitions and simplified in multi-resolutions so a large file is transformed into a number of small data files and saved in a PC server. Only selected small files specified by the user are hierarchically transmitted to the mobile system for 3D browsing and rendering. A 3D preview in a pop-up shows a simplified mesh in the lowest resolution. The next step displays simplified meshes whose resolutions are automatically controlled by the user interactions. The last step is to render a set of detailed original partitions in a selected range. As a result, while minimizing using mobile system resources, our interface enables us to browse and display 3D meshes in mobile systems through real-time interactions. A mobile 3D viewer and a 3D app are also presented to show the utility of the proposed user interface.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.53-54
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• 2008

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.1
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• pp.7-12
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• 2012

In this paper, we present an effective viewpoint estimation algorithm for the Moving parallax barrier method of 3D display mobile device. Moving parallax barrier is designed to overcome the biggest problem, the limited view angle. To accomplish it, the position of the viewer's eyes or face should be estimated with strong stability and no latency. We focus on these requirements in the poor performance of mobile processors. We used a pre-processing algorithm in order to overcome the various illumination changes. And, we combined the conventional Viola-Jones face detection method and Optical-flow algorithm for robust and stable viewpoint estimation. Various computer simulations prove the effectiveness of the proposed method.

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.369-374
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• 2016

Recently, due to the rapid development of smart computing technology, there have been a lot of studies on 3D navigation, and consequently the advanced commercial 3D navigation system and 3D VTS system are on the market. Even the 3D technology is well known and wide spreaded, unfortunately, the secret of code behind is still unleashed. The purpose of this paper is to show the basic methodologies to display ENC features under 3D display environment to meet the requirement of S-52 standards. The OpenGL ES is used to develop 3D ENC Viewer for further use on mobile platforms and web based vessel monitoring system. P articularly, area object triangulation, complex line drawing, polygon pattern filling and symbol drawing by texture mapping are explained in detail. The result of performance test is shown as table for correlation of SENC file size to display speed.