• Journal of Aerospace System Engineering
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• v.12 no.2
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• pp.37-45
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• 2018

A two-axis gimbal-type antenna for a Compact Advanced Satellite (CAS) is used to efficiently transmit high resolution image data to a ground station. In this study, we designed the structure of a two-axis gimbal-type antenna while applying a launch lock device to secure its structural safety under a launch environment. To validate the effectiveness of the structural design, a structural analysis of the antenna was performed. First, a modal analysis was performed to investigate the dynamic responses of the antenna with and without the mechanical constraints of the launch lock device. In addition, a quasi-static analysis was performed to confirm the structural safety of the antenna structure and bolt I/Fs between the antenna base and the satellite. The suitable range of constraint force on the launch lock device was also determined to ensure the structural safety and mechanical gapping of the ball & socket interfaces, which places multi-constraints on the azimuth and elevation stage of the antenna.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.3
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• pp.11-19
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• 2008

Background subtraction, which separates moving objects in video sequences, is an essential technology for object recognition and tracking. However, background subtraction methods are often confused by shadow regions and this misclassification of shadow regions disturbs further processes to perceive the shapes or exact positions of moving objects. This paper proposes a method for shadow elimination which is based on shadow modeling by color information and Bayesian classification framework. Also, because of dynamic update of modeling parametres, the proposed method is able to correspond adaptively to illumination changes. Experimental results proved that the proposed method can eliminate shadow regions effectively even for circumstances with varying lighting condition.

• Journal of Digital Contents Society
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• v.6 no.4
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• pp.201-208
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• 2005

In high-technology digital age that change everyday fast, Web became most familiar and essential tool to public. Since creation of web, web began from the first step web that offer simple information and contents. and now, it have developed to step offer dynamic contents that various multimedia components are combined. In future, it will develop to the next generation, intelligence style Semantic Web that Meta Communication of meaning-base is possible. In this paper, we examine about concept and characteristic of Semantic web that is a point technology in next generation. Also, we studied about example and practical use in personalized contents side that is based on Semantic Meta-Communication system. Semantic web is value industry field that has infinite possibility and has necessary of a lot of studies and development yet. Therefore in digital age, we expect this paper will help for space construction of more mature communication.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.5
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• pp.552-557
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• 2014

The objective of the This study is to access the speed performance employing the sea trial test and CFD with the our own designed and manufactured one-man boat. The overall design process including hull form design was explained. The sea trial was carried out with a manufactured boat in the clam sea. Brake power at the design speed of a boat through the sea trial was measured as 1680 W. The flow computation was conducted considering free surface and dynamic trim using a commercial CFD code(STAR-CCM+). The result of computation provided the information that residual resistance is bigger than fraction's at design speed. The total efficiency were predicted based on the sea trial and CFD. The Total efficiency was divided into shaft efficiency and quasi-propulsive efficiency. By using quasi-propulsive efficiency, it becomes possible to predict speed performance of boat in future. The results can provide information regarding hull form design, performance analysis and development of a boat in future.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.3
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• pp.261-268
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• 2004

Analysis on forest through satellite image data can be obtained from normalized burn ration (NBR) and normalized difference vegetation index (NDVI) from descriptive information of reflection on the earth's surface recorded each waveband. This study focuses on the efficiency of NBR through comparative analysis after obtaining NBR and NDVI of images form 1 you, 2 years and just after the forest fire and the time of forest-preserved of the area before the forest fire in Sacheon myeon, Cangneung City where the forest fro broke out. As a result, it shows dynamic changes with greater range that differences between NBR images rather than differences between NDVI images, which means it would be better to use NBR image for the analysis of the degrees of damages from forest fire or the status of vegetation restoration and also NBR image more distinctly shows both than NDVI image in forest fro damage area.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6C
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• pp.535-543
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• 2002

In order to overcome disadvantages of existing centralized network management systems that use simple objects, dynamic object platforms are proposed as alternative systems. So the distributed network management systems are implemented using various distributed platform such as CORBA and Java-RMI. Subsequently mobile agent-based platforms are proposed. The mobile agent-based platform can additionally provide flexibility and scalability to network management system that CORBA or Java-RMI based platforms do not support. In this paper, we address an architecture to solve the problem of the occurrence of additional traffic by using mobile agent and to save resources of network element. Our proposal in this paper is an efficient network management architecture using motile agents. And we make use of mobile agents for minimizing of traffic that can happen when mobile agents moves. Also we design agents using information architecture of TMN for efficient resource management of network element and improvement of operation performance.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.795-802
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• 2018

This study describes the semantic theoretic interpretation through the extensive use of semantic metaphors for intensive web interface with information and the metaphoric value of metaphors for interface design. Common factors that influence web design are empirical establishment and verification for generating web symbols and these are have important elemental perspectives that are used to assess the usefulness and key elements of the site. In addition, the structure of the screen has begun to change dynamically from the application of web technological functions, and the media functions have become important to make web standards when implementing visual structuring from the perspective of semiotic. Instead of using a technical expression approach to examine semiotic, a semiotic approach is applied to create aesthetic codes through the human-computer interface in terms of semiotic in a variety of natural and universal fields. Based on this, it is used as means of communication to convey the intended meaning to users so as to highlight the importance of the usability issues and metaphors user interface.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.9
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• pp.1081-1094
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• 2016

KREONET is a principal national R&E network running by KISTI in Korea. It uniquely provides production research network services for around 200 non-profit research and educational organizations, based on hybrid (IP and non-IP) network infrastructure. However, KREONET is limited to meet various needs of new network services for advanced Science & Technology (S&T) users because its infrastructure is inherently derived form classical hardware-based, fixed and closed environments. So, KREONET-S is designed to provide advanced S&T services to catch up with time-to-research and time-to-collaboration. In this paper, we present a system architecture of KREONET-S based on network infrastructure that consists of data and control planes separately. Furthermore, we propose and describe VDN service which is capable of building a virtual dedicate & bandwidth-guaranteed network for S&T group dynamically. we implement VDN application on KREONET-S and then perform performance analysis for proving that KREONET-S system and VDN application can be a good solutions to cope with new network paradigms for various advanced S&T applications and users.

• Archives of design research
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• v.18 no.3 s.61
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• pp.191-198
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• 2005

Menu is the most common interaction tool to select and execute a specific menu item from multiple menu options. With the very rapid increasing amount of information, various new menu designs have been developed. In this research, the pull-down menu, fisheye menu and grid menu were tested to compare the performance time, error rate, simplicity, usefulness, user friendliness, and overall user preference of each menu type. The grid menu was more efficient in selection speed than the pull-down and fisheye menus when the number of menu-items was 50 and 100. The time needed to choose a menu-item with a grid menu was less affected by the size of menu. The pull-down and the grid menus were considered to be more satisfactory, simple, user friendly, and useful than the fisheye menu. 42.3 percent of subjects indicated that the grid menu was their preferred selection tool among the menus. The grid menu is an efficient and robust alternative menu choice for small and middle size menu list. Further study is required to examine the possibility of grid menu on mobile devices.

• Broadcasting and Media Magazine
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• v.11 no.4
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• pp.118-131
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• 2006

With rapid development in ultra fast communication and digital multimedia, the realistic broadcasting technology, that can stimulate five human senses beyond the conventional audio-visual service is emerging as a new generation broadcasting technology. In this paper, we introduce a haptic broadcasting system and related core system and component techniques by which we can 'touch and feel' objects in an audio-visual scene. The system is composed of haptic media acquisition and creation, contents authoring, in the haptic broadcasting, the haptic media can be 3-D geometry, dynamic properties, haptic surface properties, movement, tactile information to enable active touch and manipulation and passive movement following and tactile effects. In the proposed system, active haptic exploration and manipulation of a 3-D mesh, active haptic exploration of depth video, passive kinesthetic interaction, and passive tactile interaction can be provided as potential haptic interaction scenarios and a home shopping, a movie with tactile effects, and conducting education scenarios are produced to show the feasibility of the proposed system.