• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.93-96
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• 2008

This paper describes an efficient design of a multi-standard Viterbi decoder that supports multiple constraint lengths and code rates. The Viterbi decode. is parameterized for the code rates 1/2, 1/3 and constraint lengths 7, 9, thus it has four operation modes. In order to achieve low hardware complexity and low power, an efficient architecture based on hardware sharing techniques is devised. Also, the optimization of ACCS (Accumulate-Subtract) circuit for the one-point trace-back algorithm reduces its area by about 35% compared to the full parallel ACCS circuit. The parameterized Viterbi decoder core has 79,818 gates and 25,600 bits memory, and the estimated throughput is about 105 Mbps at 70 MHz clock frequency.

• Journal of the Institute of Convergence Signal Processing
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• v.4 no.2
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• pp.31-39
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• 2003

The MPEG-2 source coding algorithm is very sensitive to transmission errors due to using of variable-length coding. When the compressed data are transmitted, transmission errors are generated and error correction scheme is not able to be corrected well them. In the decoder error concealment (EC) techniques must be used to conceal errors and it is able to minimize degradation of video quality. The proposed algorithm is method to conceal successive macroblock errors of I-frame and utilize temporal information of B-frame and spatial information of P-frame In the previous GOP which is temporally the nearest location to I-frame. This method can improve motion distortion and blurring by temporal and spatial errors which cause at existing error concealment techniques. In network where the violent transmission errors occur, we can conceal more efficiently severe slice errors. This algorithm is Peformed in MPEG-2 video codec and Prove that we can conceal efficiently slice errors of I-frame compared with other approaches by simulations.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.91-99
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• 2014

The main game architectures for multiplayer online games are the traditional client-server architectures, multi-server architectures and P2P(peer-to-peer) architectures. P2P architectures, due to their distributed and collaborative nature, have low infrastructure costs and can achieve high scalability as well as fast response time by creating direct connections between players. However, P2P architectures face many challenges. Distributing a game among peers makes maintaining control over the game more complex. These architectures also tend to be vulnerable to churn and cheating. Providing consistency control in P2P systems is also more difficult since conflicting updates might be executed at different sites resulting in inconsistency. In order to avoid or correct inconsistencies, most multiplayer games use a primary-copy replication approach where any update to the object has to be first performed on the primary copy. This paper presents the primary-copy model with the update dissemination mechanism that provides consistency control over an object in P2P architectures for multiplayer online games. The performance for this model is evaluated through simulation experiments and analysis.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.6
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• pp.709-717
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• 2002

A new multi constant modulus algorithm (MCMA) for a blind decision feedback equalizer is proposed. In order to avoid the error propagation problem in the conventional DFE structure, Feed-Back Filter coefficients are updated only after Feed-Forward Filter coefficients are sufficiently converged to the steady state. Therefore, it has the problem of slow convergence speed characteristics. To overcome this drawback, the proposed MCMA algorithm uses not only new cost function considering the minimum distance between the received signal and the representative value containing the statistical characteristics of the transmitted signal, but also adaptive step-size according to the equalizer outputs to fast convergence speed of FBF. Simulations were carried out under the certified communication channel environment to evaluate a performance of the proposed equalizer. The simulation results show that the proposed equalizer has an improved convergence and SER performance compared with previous methods. The proposed techniques offer the possibility of practical equalization for cable modem and terrestrial HDTV broadcast (using 8-VSB or 64-QAM) applications.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.817-822
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• 2008

The computer game industry has been developed gradually because of development of graphics and communication industry, Games have an important role to peoples in various ages in their leisure life. Game has been changed into various forms with its development. With this movement, it is not only for simple amusement, but starts trying to use them for educational object. It is called Serious Game that intends to particular object and effect. Serious game has the important meaning to get some new useful things through its enjoyment which is the essence of games. Many people in various field have tried many categories of contents. Especially, education stands out among the other fields. Fields related with education have been studied extensively. This paper would suggest mathematics education game based on Augmented Reality. It is a board game for infants and young students. Augmented Reality is used to extend user's experience and multiplicity of the game. We also offer users a tool that helps them to create their own board for their active game participation.

• Horticultural Science & Technology
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• v.16 no.3
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• pp.358-360
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• 1998

Series of in vitro experiments in Lilium callosum were conducted to investigate efficient multiplication through finding the optimal cultural environment, and organogenic capability of cultural explants, and then to determine the progressive method for enhancing bulblet growth in Lilium callosum scale culture. Twenty-four hr photoperiod was most effective for the growth of bulblet and the formation of other organs. Optimum light intensity for bulblet growth was 2,500~5,000 Lux. When bulbets were subcultured, growth of bulblets were enhanced by removing excessive leaf blade. Number of bulblets per scale increased as mother scale size increased, whereas diameter of bulblet from the small size mother scale increased. Bulblet formation and development was induced when explants were placed above the medium to be exposed to more light.

• Ocean and Polar Research
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• v.33 no.1
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• pp.1-11
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• 2011

This study describes measurements of fast ice recorded on May 23, 2009, in Kongsfjorden (translated as 'Kongs Fjord'), an inlet on the west coast of Spitsbergen in the Svalbard Archipelago. Seasonal fast ice is an important feature for Svalbard fjords, both in relation to their physical environment and also the local ecosystem, since it grows seaward from the coast and remains in place throughout the winter. Ice thickness, snow, ice properties, and wind speed were measured, while SAR (Synthetic Aperture Radar) data was observed simultaneously observed two times from ALOS-PALSAR (L-band). Measured ice thickness was about 25-35 cm while the thickness of ice floe broken from fast ice was measured as 10-15 cm. Average salinity was 1.9-2.0 ppt during the melting period. Polarimetric data was used to extract H/A/alpha-angle parameters of fast ice, ice floe, snow and glacier, which was classified into 18 classes based on these parameters. It was established that the area of fast ice represents surface scattering which indicates low and medium entropy surface scatters such as Bragg and random surfaces, while fast ice covered with snow belongs to a zone of low entropy surface scattering similar to snow-covered land surfaces. The results of this study will contribute to various interpretations of interrelationships between H/A/alpha parameters and the wave scattering Phenomenon of sea ice.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.12
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• pp.1935-1940
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• 2009

This study investigates the actual wearing conditions of functional mountaineering garments in Korea and provides suggestions on the development of more effective functional mountaineering garments through the examination of consumer data. This survey was based on 107 respondents who enjoy mountaineering and was composed of 5 sections consisting of personal information, purchasing habits, essential features for mountaineering garments, satisfaction levels based on features and functions, and additional comments on the improvement of mountaineering garments. Respondents said that essential features for mountaineering garments are quick absorbing/drying, insulation, water and wind proof, and elasticity. These properties become more effective when users wear mountaineering garments in layers. They want lower prices and easy to wash garments. Therefore, it is necessary to consider not only the main functions, but also the needs of consumers for easy washing and price.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.160-164
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• 2003

Broadcasting environment of present our country is greeting period of transition that undergo a change to digital broadcasting system in analog broadcasting system continued for last several decades. With change of these broadcasting environment interest about various digital broadcasting contents industry that fill to digital broadcasting infra and unlawfulness reproduction prevention technology far digital broadcasting contents of high added value is rising. According as is converted to digital broadcasting environment interest about reproduction prevention is well-founded to be risen sensitively. First analog broadcasting environment can not remove perfectly error at transmission in receiver, but can reconstruct contents such as original by error correction function in receiver in the case of digital broadcasting environment. Secondarily, although quality of copy is dwindled than original repeat reproduction in case of analog, many copies are available innumerably regardless of number of times of copy keeping quality such as original in the case of digital And third element is possible easily to anyone to on-line along with development of internet in case of digital contents unlike analog. Under these background, this thesis wish to design and implement digital contents protection system to prevent unlawfulness reproduction and distribution of digital contents using Triple DES algorithm.

• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.110-121
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• 2009

In this paper, we propose the new method that offer detailed-information through relax the system memory limitation about 3D model to user. That method based on making LOD(Level of Detail) model from huge 3D data of structure cultural assets. In our method as transformed AOSP algorithm, first of all it create the hierarchical structure space about 3D data, and create the LOD model by surface simplification. Then it extract the ROI(Region of Interest) of user in simplified LOD model, and then do rendering by original model and same surface detailed-information after process the local detailed in extracted region. To evaluate the proposed method, we have some experiment by using the precise 3D scan data of structure cultural assets. Our method can offer the detailed-information same as exist method, and moreover 45% reduced consumption of memory experimentally by forming mesh structure same as ROI of simplified LOD model. So we can check the huge structure cultural assets particularly in general computer environment.