• Journal of KIISE:Software and Applications
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• v.31 no.10
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• pp.1332-1344
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• 2004

Upon development of information super-highway and multimedia-related technoiogies in recent years, more efficient technologies to transmit, store and retrieve the multimedia data are required. Among such technologies, firstly, it is common that the semantic-based image retrieval is annotated separately in order to give certain meanings to the image data and the low-level property information that include information about color, texture, and shape Despite the fact that the semantic-based information retrieval has been made by utilizing such vocabulary dictionary as the key words that given, however it brings about a problem that has not yet freed from the limit of the existing keyword-based text information retrieval. The second problem is that it reveals a decreased retrieval performance in the content-based image retrieval system, and is difficult to separate the object from the image that has complex background, and also is difficult to extract an area due to excessive division of those regions. Further, it is difficult to separate the objects from the image that possesses multiple objects in complex scene. To solve the problems, in this paper, I established a content-based retrieval system that can be processed in 5 different steps. The most critical process of those 5 steps is that among RGB images, the one that has the largest and the smallest background are to be extracted. Particularly. I propose the method that extracts the subject as well as the background by using an Image, which has the largest background. Also, to solve the second problem, I propose the method in which multiple objects are separated using RGB channel selection techniques having optimized the excessive division of area by utilizing Watermerge's threshold value with the object separation using the method of RGB channels separation. The tests proved that the methods proposed by me were superior to the existing methods in terms of retrieval performances insomuch as to replace those methods that developed for the purpose of retrieving those complex objects that used to be difficult to retrieve up until now.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.3
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• pp.268-275
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• 2003

In this paper, the capacity of VSG-CDMA system supporting multi-media service in the reverse link is analyzed by considering the two models according to the power control and user distribution. In analysis model I, assuming perfect power control and uniform distribution of users, the equation of blocking probability is calculated and the maximum number of voice and data user is derived in accordance with 1 % blocking probability. In analysis model II, it is analyzed by assuming power control error and non-uniform distribution of users. The result of analysis model I means the upper bound of system capacity in the 5 MHz wideband VSG-CDMA system, and the result of analysis model II shows the lower bound of system capacity. Also, the improved plan of performance for VSG-CDMA system is suggested by the analyzed result according to data activity and the value of $E_b/N_o$ in model II.

• Journal of Advanced Navigation Technology
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• v.6 no.3
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• pp.241-250
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• 2002

This paper presents a way to maximize transmission efficiency and reception ability through transmission diversity technology, which can be adapted to wireless multimedia OFDM system. The presented method is a comparative analysis between a case where parameter ${\alpha}$ for time average is 0.3, 1 with consideration of channel presumption with two types of rms delayed spread, which is 50nsec, 150nsec, for the performance analysis of STTC(Space-Time Trellis Code) using time-space ciphering method appropriate for MIMO channel, and performance in the case where presumed channel value from long training column section is applied to according frame in a single frame. The result showed that BER brought SNR improvement of 1.0 dB in $10^{-3}$ when ${\alpha}$ was 0.3 than using only the long training column, and showed increase of general performance improvement for the sake of time average rather than the case without.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11A
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• pp.1059-1065
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• 2010

Recently, analog broadcasting are being converted into digital radio broadcasts, Among the various ways that HD Radio is a candidate for the U.S. approach, Digital Radio will transmit a digital signal to existing analog FM/AM. It provides clear sound quality, traffic information, weather information and various value-added services. In addition, the converted digital radio will be able to meet demand to growing demand for analog FM. In this paper, Digital FM Radio system in the same frequency band using electric field strength of the received digital radio broadcasting interference effects were analyzed. And Digital FM Radio Receiver interference effects were analyzed by interference signal power and signal power. Results were confirmed by applying equation at minimum field strength and SNR.

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.11-18
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• 2011

The increasing of web users load to the excessive transmission traffic and system overload problems. To solve these problems, cluster systems are studied. In conventional cluster systems, when the request size is large owing to such types as multimedia and CGI, the particular server load and response time tend to increase even if the overall loads are distributed evenly. In this paper, we consider the methodology of efficient resource usage, specially distributed web cluster system. We develope an algorithm that distributes the load on the web cluster system to use the system resources, such as system memory equally. The response time is chosen as a performance measure on the various clustering models. And based on the concurrent user to the web cluster system, the response time is also examined as the number of users increases. Simulation experience with this algorithm shows that the response time and average throughput seems to have a good results compare to those with the other algorithm.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.2 no.2
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• pp.36-45
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• 2003

This paper presents a way to maximize transmission efficiency and reception ability through transmission diversity technology, which can be adapted to wireless multimedia OFDM (orthogonal FDM) system. The presented method gives a comparative analysis between a case where parameter a for time average is 0.3, i with consideration of channel presumption and two types of rms delayed proliferation, which is 50nsec, 150nsec, for the performance analysis of STTC (Space-Time Trellis Code) using time-space code method which is appropriate for MIMO channel, and performance, in the case, where presumed channel value from long training column section is applied to the according frame in a single frame. The result shows that BER brought SNR improvement of 1.0dB in $10^{-3}$ when a was 0.3 than using only the long training column, and shows an increasement of general performance improvement when the time average factor is used.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.8
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• pp.1384-1390
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• 2008

The TCP protocol is originally designed for wired network, however it performs very poor in wireless network due to different nature of wireless network from wired networks. In terms of TCP performance improvement in wireless Ad-hoc network, many researches show that small congestion window size of TCP connection can improve TCP performance. We propose a new TCP algorithm to improve TCP performance in wireless Ad-hoc network. The basic idea of our approach is that TCP receiver estimates the optimum window size and then sets congestion window limit of TCP sender to an optimum value by using the advertised window field in TCP ACK packet. From extensive computer simulation, the proposed algorithm shows superior performance than traditional TCP protocols in terms of packet delivery ratio and packet loss.

• Journal of the Korea Society of Computer and Information
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• v.14 no.12
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• pp.191-199
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• 2009

The integrated medical information system is an effective medical diagnosis assistance system which offers an environment in which medial images and diagnosis information can be shared. Because of the large-scale medical institutions and their cooperating organizations are operating the integrated medical information systems, they can share medical images and diagnosis information. However, this system can only stored and transmitted information without other functions. To resolve this problem and to enhance the efficiency of diagnostic activities, a medical image analysis system is necessary. In this paper, the proposed relationship method analyzes medical images for features generation. Under this method, the medical images have been segmented into several objects. The medical image features have been extracted from each segmented image. Then, extracted features were applied to the Relationship Method for medical image analysis. Several experimental results that show the effectiveness of the proposed method are also presented.

• Journal of the Korea Society of Computer and Information
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• v.14 no.9
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• pp.105-113
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• 2009

This paper is aimed at embodying the optimal system for foreign workforce supply of nation in order to introduce qualified foreign workers at the age of eleven thousand foreigners. It is difficult to employ foreign workers qualified and it makes job rosters' confidence fall down which is the supplementary resources when selecting due to the insufficient job seekers' detailed information. Therefore, the moving control system should be added in current system to deal with these problems. For this, in this paper, we propose that the moving picture embedded system applies to the current EPS utilizing multimedia, network and database technologies as regards adding the function of the moving picture synthesis to recent system. It also suggests the advanced foreign employment control system related to the advanced system which makes employers to hire foreign workers satisfying their requirements and demand.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.165-168
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• 2008

With the development of the information technology in recent years, the innovation of multimedia information technology also has been accelerated. Many fields of the digital image processing technologies as image data compression, recognition. restoration, etc. are now being studied actively. When transmitting and saving digital images, noise would be made, and we are using the image filters to remove the noise. The Image Filter used Digital Image Process basically has a two-dimensional structure. There are two methods of the filter's creation - One is reiterating one dimension, and the other is using an indivisible two-dimension image filter. The space domain method using mask is the latter one. That is inserting the value-multiplied pixels values faced each other when the two-dimension filter overlapped on input image- to the filter value's center position and the same position in the image. The image filter is being used widely along with one-dimension filter, according each noise. Most people are using various median filters to remove the impulse noise. However, in this paper, I suggested a powerful switching median filter and compared with conventional method for verification.