• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.3
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• pp.71-82
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• 2009

As a solution to spectrum under-utilization problem, Cognitive radio (CR) introduces a dynamic spectrum access technology. In the area, one of the most important problems is how secondary users (SUs) should choose between the available channels, which means how to achieve load balancing between channels. We consider spectrum load balancing problem for CR system in frequency domain and especially in time domain. Our objective is to balance the load among the channels and balance the occupied time length of slots for a fixed channel dynamically in order to obtain a user-optimal solution. In frequency domain, we refer to Dynamic Noncooperative Scheme with Communication (DNCOOPC) used in distributed system and a distributed Dynamic Spectrum Load Balancing algorithm (DSLB) is formed based on DNCOOPC. In time domain, Spectrum Load Balancing method with QoS support is proposed based on Dynamic Feed Back theory and Hash Table (SLBDH). The performance of DSLB and SLBDH are evaluated. In frequency domain, DSLB is more efficient compared with existing Compare_And_Balance (CAB) algorithm and gets more throughput compared with Spectrum Load Balancing (SLB) algorithm. Also, DSLB is a fair scheme for all devices. In time domain, SLBDH is an efficient and precise solution compared with Spectrum Load Smoothing (SLS) method.

• International journal of advanced smart convergence
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• v.7 no.3
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• pp.130-139
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• 2018

This study is to analyze the relationship between character and human semantic production through research on character visualization artworks and to develop a creative platform that visually expresses the formative and semantic dynamics of characters using the results will be. The 3D spatial interaction system using the character visualization proposed generates the transformation of the character in real time using the interaction with user and the deconstruction of the character structure. Transformations of characters including the intentions of the viewers provide a dynamic visual representation to the viewer and maximize the efficiency of meaning transfer by producing various related meanings. The method of dynamic deconstruction and reconstruction of the characters provided by this system creates special shapes that viewers cannot imagine until now and further extends the interpretation range of the meaning of the characters. Therefore, the proposed system not only induces an active viewing attitude from viewers, but also gives them an opportunity to enjoy watching the artwork and demonstrate creativity as a creator. This system induces new gestures of the viewer in real time through the transformation of characters in accordance with the viewer''s gesture, and has the feature of exchanging emotions with viewers.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.3
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• pp.371-379
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• 2011

In this paper, we propose a development methodology of interactive stereoscopic image display system. In our case, we consider a multiple touch recognition technique as the interaction method. That's because we want to guarantee multiple user access and interaction to the content without any restriction. In this case, however, some restrictions are occurred on account of the distance between display and participants. For this reason, this paper propose an invisible interaction surfaces which are generated in the air. This surface is utilized as interaction medium instead of the display wall. We also present an effective way to generate and edit interactive stereoscopic images based on Game Engine.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.12B
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• pp.1060-1065
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• 2003

As the Internet continues to grow, network games are widely spreaded. For most network games, many users' meet on a server causes a heavy load to the sewer, which in turn brings inconvenience to the user. Moreover, it demands increased expense to the service provider for deploying additional servers. In this paper, we propose a hybrid distributed system for network games. In our proposed system, a client is independents of the server and exchanges information directly with other clients. The client depends on servers only for the update information. The proposed methodology classifies messages according to the characteristics of information that the message handles and applies either client-to-server and pear-to-pear communication for processing messages which increases the efficiency of systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2937-2943
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• 2013

This paper introduces a real-time flocking simulation framework through radial basis function(RBF). The proposed framework first divides the entire environment into a grid structure and then assign a vector per each cell. These vectors are automatically calculated by using RBF function, which is parameterized from user-input control lines. Once the construction of vector field is done, then, flocks determine their path by following the vector field flow. The collision with static obstacles are modeled as a repulsive vector field, which is ultimately over-layed on the existing vector field and the inter-individual collision is also handled through fast lattice-bin method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1986-1992
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• 2009

A user often searches a data by inputting a variant such as the abbreviation or substring of a word, or a misspelled word. The simple approach to the searching for variants is to build a variants dictionary. However, it entails enormous cost and time and can not handle variants by misspelling. Approximate searching, searching by approximate string matching, is a good approach to the searching. A problem in the approach is that it cannot handle variants by abbreviations. This paper propose a method for searching various variants including abbreviations and misspelled words, by using the trie indexing. First, this paper shows a variant matching method with the calculation of path weighted-metric. In addition, it provides variant searching algorithm to reduce the search time.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1587-1596
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• 2016

This paper presents an interactive locomotion controller using motion capture data and inverted pendulum model. Most of the data-driven character controller using motion capture data have two kinds of limitation. First, it needs many example motion capture data to generate realistic motion. Second, it is difficult to make natural-looking motion when characters navigate dynamic terrain. In this paper, we present a technique that uses dimension reduction technique to motion capture data together with the Gaussian process dynamical model (GPDM), and interpolates the low-dimensional data to make final motion. With the low-dimensional data, we can make realistic walking motion with few example motion capture data. In addition, we apply the inverted pendulum model (IPM) to calculate the root trajectory considering the real-time user input upon the dynamic terrain. Our method can be used in game, virtual training, and many real-time applications.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.5
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• pp.991-1000
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• 2019

The flying-disc game has started since 1940. It has been spreading rapidly in Korea since 2007, mainly in elementary schools. Additionally, as sports science has been developed, research on flying discs has been continued to build a monitoring system for technological improvement and efficiency. In this paper, we acquire information on the user's flying-disc using 9-axis motion sensor and GPS. Then we propose a method for wireless transmission using Bluetooth 5.0. Specifically, the HW platform was designed and implemented not only to monitor a real-time data but also to compare and analyze rotational speed, flight trajectory, and a count of disc rotation through post-processing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.451-454
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• 2009

There are a lot of multimedia functions getting included in mobile devices recently, not only simple audio but visual functions as well, such as video playing, game and web browsing. Such the visual multimedia functions brought the strong requirement for much bigger LCD Display and high resolution. And the brightness of LCD is also one of major requirements and it is required to be more bright However, LCD brightness is limited to increase because of power consumption. It occupies nearly 30% of the whole system power. This thesis suggests an effective and simple method of adjusting the LCD backlight brightness, considering a characteristic of battery and user pattern.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.97-102
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• 2021

In this study, we developed the service that can efficiently making friends among college students in metaverse world. Metaverse technology has recently emerged as an important topic across the industry.' The development of virtual and augmented reality technologies, which have emerged as a new paradigm to drive the next generation of the Internet, is bringing us closer to the metaverse world. Metaverse is spreading around the gaming, entertainment, music, and content industries[1]. In particular, as non-face-to-face transitions have accelerated since the COVID-19 outbreak, lifestyles and industrial sites are rapidly changing beyond untacting to metaverseization, a three-dimensional virtual space. After discovering the needs of users through surveys and interviews, the research method added functions to the service that matched those needs. Users were pleased that they could make friends who matched their preferences and tastes, play like a game in a virtual world called metaverse, and customize their avatars to their liking. It was also very fresh to customize the goods so that they could be gifted and kept by themselves.