• Journal of Broadcast Engineering
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• v.19 no.2
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• pp.268-271
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• 2014

Conventional forward error correction (FEC) code rate decision schemes using analytical source coding distortion model and channel-induced distortion model are usually complex, and require the typical process of model parameter training which involves potentially high computational complexity and implementation cost. To avoid the complex modeling procedure, we propose a simple but accurate joint source-channel distortion model to estimate channel loss threshold set for optimal FEC code rate decision.

• Journal of Communications and Networks
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• v.10 no.4
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• pp.384-395
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• 2008

Random network coding can be viewed as a single block code applied to all source packets. To manage the concomitant high coding complexity, source packets can be partitioned into generations; block coding is then performed on each set. To reach a better performance-complexity tradeoff, we propose a novel concatenated network code which mixes generations while retaining the desirable properties of generation-based coding. Focusing on the code's erasure performance, we show that the probability of successfully decoding a generation on erasure channels can increase substantially for any erasure rate. Using both analysis (for small networks) and simulations (for larger networks), we show how the code's parameters can be tuned to extract best performance. As a result, the probability of failing to decode a generation is reduced by nearly one order of magnitude.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.11-19
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• 2021

A software system is required to change during its life cycle due to various requirements such as adding functionalities, fixing bugs, and adjusting to new computing environments. Such program code modification should be considered as carefully as a new system development becase unexpected software errors could be introduced. In addition, when reusing open source programs, we can expect higher quality software if code changes of the open source program are predicted in advance. This paper proposes a Convolutional Neural Network (CNN)-based deep learning model to predict source code changes. In this paper, the prediction of code changes is considered as a kind of a binary classification problem in deep learning and labeled datasets are used for supervised learning. Java projects and code change logs are collected from GitHub for training and testing datasets. Software metrics are computed from the collected Java source code and they are used as input data for the proposed model to detect code changes. The performance of the proposed model has been measured by using evaluation metrics such as precision, recall, F1-score, and accuracy. The experimental results show the proposed CNN model has achieved 95% in terms of F1-Score and outperformed the multilayer percept-based DNN model whose F1-Score is 92%.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.796-800
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• 2006

In this paper, we developed an e-loaming contents for C programming language using Linux and open source software, not using commercial integrated development tool like Microsoft's Visual Studio. In most programming language courses, students study or practice the programming language by editing source code compiling and running the executable code by commercial software like Visual Studio which installed on each PC. This way of learning has some difficulties in total cost of purchasing software and using other PCs which donot have proper software installed. To overcome this situation and enable loaming anywhere, with any device, at anytime, we propose a way of utilizing Linux and open source software in Web-based learning environment. In this environment students can input their source code on the form of broweser and get the result instantly from the server.

• Journal of Advanced Navigation Technology
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• v.10 no.3
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• pp.250-255
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• 2006

In digital multimedia society, we usually use the digital sound music ( Mp3, wav, etc.) system instead of analog music. In the middle of generating or recording and transmitting, if we embed the digital code which is useful to music information, we can easily select as well as classify the music title by using Mp3 player that embedded sound source classification system. In this paper, sound source classification system which could be classify and search a music informations by way of user friendly scheme is implemented. We performed some experiments to testify the validity of proposed scheme by using implemented system.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.12
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• pp.1345-1354
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• 2015

This paper, information communication code standard($KS{\times}1001$, confirmation in 2004), as definded in Hangul Character Code Hangul AMI/HDB-3 the code set for the new system Hangul consonant and vowel tables presented. The result of the existing system and the code set ($4{\times}4$) bit source coding rules for comparing the frequency of use Hangul consonant and vowel tables(The National Institute of The Korea Language) and statistices showed that 44% of the data processing efficiency is improved.

• Earthquakes and Structures
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• v.12 no.1
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• pp.91-108
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• 2017

Superstructures and isolation systems of seismically isolated buildings located close to active faults may observe increased seismic demands resulting from long-period and high-amplitude velocity and displacement pulses existent in near-fault ground motions as their fundamental periods may be close to or coincident with these near-fault pulse periods. In order to take these effects into account, the 1997 Uniform Building Code (UBC97) has specified near-source factors that scale up the design spectrum depending on the closest distance to the fault, the soil type at the site, and the properties of the seismic source. Although UBC97 has been superseded by the 2015 International Building Code in the U.S.A., UBC97 near-source factors are still frequently referred in the design of seismically isolated buildings around the world. Therefore it is deemed necessary and thus set as the aim of this study to assess the necessity and the adequacy of near-source factors for seismically isolated buildings. Benchmark buildings of different heights with isolation systems of different properties are used in comparing seismic responses obtained via time history analyses using a large number of historical earthquakes with those obtained from spectral analyses using the amplified spectrums established through UBC97 near-source factors. Results show that near-source factors are necessary but inadequate for superstructure responses and somewhat unconservative for base displacement response.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.5
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• pp.229-234
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• 2017

Because of the invisible nature of software and the bad coding habits (bad smell) of the existing developers, there are many redundant codes and unnecessary codes, which increases the complexity and makes it difficult to upgrade software. Therefore, it is required a code visualization so that developers can easily and automatically identify the complexity of the source code. To do this, it is necessary to construct SW visualization tool based on open source software and redefine the coupling and cohesion according to the object oriented viewpoint. Specially to identify a bad smell code pattern, we suggest how to plug-in diverse parsers within our tool. In this paper, through redefining coupling and cohesion from an object oriented perspective, we will extract bad smell code patterns within source code from inputting any pattern into the tool.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.4
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• pp.334-341
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• 2023

The purity of hydrogen finally purified in the hydrogen purification process system is greatly influenced by the uniformity of the purification temperature of the dry tower. A in-house code that can be easily used by field designers has been developed to predict the capacity of the appropriate heat source and the time to reach the temperature of the dry tower. A code was developed to predict unsteady heat transfer using Visual Basic for Applications. To verify the developed code, a grid independence test was performed, and finally, calculations were performed for two cases. In the first case, the time for the temperature of the heater jacket to reach 360℃ was about 1,400 seconds when the supply heat source was 1,000 W. And in the second case, the time for the temperature of the heater jacket to reach 360℃ was about 710 seconds when the supply heat source was 2,000 W. It was confirmed that the developed code well describes the actual test data of the regeneration process of adsorption and desorption, and it is judged that the code developed in the design process of various capacity systems will be effectively applied to the heat capacity calculation in the future.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.2107-2110
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• 2002

소프트웨어를 설계, 구현하는데 있어서의 어려움이란 주변 환경이나 제반 기술 등과 같은 어려움도 있겠지만 실제 프로그래머가 작성하는 소스코드의 복잡성도 그 원인중의 하나라 할 수 있다. 이와 같은 문제의 해결을 위해서는 소스코드의 접근이나 이의 테스트를 위한 결합 등의 유연성이 높은 소프트웨어 기술이 필요한 실정이다. 이에 따라 AOP(Aspect-Oriented Programming) 기술을 이용하여 소스코드 자체의 접근 및 그의 처리를 용이하게 하여 복잡한 시스템의 개발이나 기존 시스템의 관리에 있어 효율을 높이고자 한다.