• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.121-124
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• 2001

Dynamic Source Route(DSR) protocol is a simple and efficient routing protocol designed specially for use of the multi-hop Ad Hoc Network. DSR allows the network to be completely self-organized and self-configured without the need for any existing infrastructure or administration. DSR protocol consists of the two mechanisms of Router discovery and Router Maintenance, works entirely On-demand in all aspects. In this paper, we will present the performance of DSR protocol on the multi-hop wireless Ad Hoc Networks, illustrate it with simulation, and then analysis the algorism of DSR.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.9-14
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• 2002

We propose a new algorithm for blind source separation (BSS), in which frequency-domain independent component analysis (FDICA) and time-domain ICA (TDICA) are combined to achieve a superior source-separation performance under reverberant conditions. Generally speaking, conventional TDICA fails to separate source signals under heavily reverberant conditions because of the low convergence in the iterative learning of the inverse of the mixing system. On the other hand, the separation performance of conventional FDICA also degrades significantly because the independence assumption of narrow-band signals collapses when the number of subbands increases. In the proposed method, the separated signals of FDICA are regarded as the input signals for TDICA, and we can remove the residual crosstalk components of FDICA by using TDICA. The experimental results obtained under the reverberant condition reveal that the separation performance of the proposed method is superior to that of conventional ICA-based BSS methods.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1707-1709
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• 2003

This paper deals with the analysis of actual state and establishment method of the power source installations in the entertainment spaces. This paper shows the result that investigate actual state of the power source installations in the entertainment spaces. In this paper, in other to improve the safely and authoritativeness of entertainment spaces, an author propose establishment method of the power source installations in consideration of the special quality of stage equipments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.27 no.1
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• pp.135-138
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• 2023

In this paper, we study real-time error in the context of monitoring a binary information source through a delay system. To derive the average real-time error, we model the delay system as a discrete time Geo/D/1/1 queueing model. Using a discrete time three-dimensional Markov chain with finite state space, we analyze the queueing model. We also perform some numerical analysis on various system parameters: state transition probabilities of binary information source; transmission times; and transmission frequencies. When the state changes of the information source are positively correlated and negatively correlated, we investigate the relationship between transmission time and transmission frequency.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.709-710
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• 2008

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4692-4697
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• 2014

A micro-grid including photovoltaic source and Li battery has been installed and operated for several years at the campus of USF and been used as a test bed. Photovoltaic power source has been strongly influenced by the location, weather and climate of the installed area. To compensate for the uncertainty of photovoltaic source's power output, a Li battery is connected directly to the photovoltaic source and supplies electric power to the grid. The Li battery is operated to supply power output to the grid according to the charging or discharging mode of the battery based on the average power output of the photovoltaic source, which is calculated from the monitored data for several years. The grid of the photovoltaic and Li battery system is operated as a severe loading condition and the operating characteristics of PV source and Li battery cells are analyzed in detail.

• Journal of Energy Engineering
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• v.19 no.3
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• pp.143-150
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• 2010

Line source method of borehole system assumes the entire surrounding medium is uniform. However, thermal properties of grouting region are considerably different from those of surrounding soil. In this study we investigate the effect of grouting materials on the solution of line source method with the aid of numerical analysis. This numerical model generates the temperature of borehole fluid with which line source solution can be obtained. Then this solution can be compared with input condition of numerical model. The results of this comparison show that thermal conductivity and borehole thermal resistance of line source solution are approximately 86% and 91% of the input condition of numerical model. Chart method is developed in this study to find the numerical input conditions (thermal conductivity and borehole thermal resistance) from the line source solution. Thermal response test of test borehole is conducted, the results of which are approximately consistent with the Chart method. Thermal property changes of grouting materials on the line source solution are also examined.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.199-204
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• 2019

This study was designed to identify the expected effects and implications of STEAM education using open source-based knitwear to be designed as an open source task in the future by analyzing the current status, trends and case studies of domestic and foreign STEAM education using open source widely used in various fields. As a research method, the theoretical examination was conducted based on the literature research, and the current status and trend of STEAM education using open source at home and abroad were investigated and analyzed. As a result, the social interest in STEAM education using open source was confirmed to be increasing, and the education was designed for the purpose of generating interest, self directed learning ability, and creative thinking development, and the positive effects of the education were visible. Based on these implications, the expected effects of using an open source made knitter are presented and the design direction and significance of the STEAM training to be designed in the future are reviewed.

• Journal of KIISE:Software and Applications
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• v.35 no.7
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• pp.442-451
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• 2008

Most plagiarism detection systems evaluate the similarity of source codes and detect plagiarized program pairs. If we use the source codes in plagiarism detection, the source code security can be a significant problem. Plagiarism detection based on target code can be used for protecting the security of source codes. In this paper, we propose a new plagiarism detection technique for Java programs using bytecodes without referring their source codes. The plagiarism detection procedure using bytecode consists of two major steps. First, we generate the token sequences from the Java class file by analyzing the code area of methods. Then, we evaluate the similarity between token sequences using the adaptive local alignment. According to the experimental results, we can find the distributions of similarities of the source codes and that of bytecodes are very similar. Also, the correlation between the similarities of source code pairs and those of bytecode pairs is high enough for typical test data. The plagiarism detection system using bytecode can be used as a preliminary verifying tool before detecting the plagiarism by source code comparison.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.4
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• pp.709-722
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• 2022

The recent "Log4j Security Vulnerability Incident" has occurred, and the information system that uses the open source "Log4J" has been exposed to vulnerabilities. The incident brought great vulnerabilities in the information systems of South Korea's major government agencies or companies and global information systems, causing problems with open source vulnerabilities. Despite the advantages of many advantages, the current development paradigm, which is developed using open source, can easily spread software security vulnerabilities, ensuring open source safety and reliability. You need to check the open source. However, open source vulnerability scan tools have various languages and functions. Therefore, the existing software evaluation criteria are ambiguous and it is difficult to evaluate advantages and weaknesses, so this paper has developed a new evaluation criteria for the vulnerability analysis tools of open source