• The Journal of Korean Association of Computer Education
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• v.18 no.4
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• pp.63-70
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• 2015

Program source code is a set of complex syntactic information which are expressed in text forms, and contains complex logical structures. Structural and logical complexity inside source code become barriers in applying visualization techniques shown in traditional big-data approaches when the volume of source code become over ten-thousand lines of code. This paper suggests a procedure for making visualization of structural characteristics in source code. For this purpose, this paper defines internal data structures as well as inter-procedural relationships among functions. The paper also suggests a means of outlining the structural characteristics of source code by visualizing the source codes with network forms The result of the research work can be used as a means of controling and understanding the massive volume of source code.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.39-47
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• 2021

Lempel-Ziv coding is one of the most famous source coding schemes. The output of this source coding is usually a non-uniform code, which requires additional source coding, such as arithmetic coding, to reduce a redundancy. However, this additional source code increases complexity and decoding latency. Thus, this paper proposes the optimal maximum a-posteriori (MAP) receiver for non-uniform source non-orthogonal multiple access (NOMA) with symmetric superposition coding (SSC). First, we derive an analytical expression of the bit-error rate (BER) for non-uniform source NOMA with SSC. Then, Monte Carlo simulations demonstrate that the BER of the optimal MAP receiver for the non-uniform source improves slightly, compared to that of the conventional receiver for the uniform source. Moreover, we also show that the BER of an approximate analytical expression is in a good agreement with the BER of Monte Carlo simulation. As a result, the proposed optimal MAP receiver for non-uniform source could be a promising scheme for NOMA with SSC, to reduce complexity and decoding latency due to additional source coding.

• 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.

• 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.

• Journal of Internet Computing and Services
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• v.7 no.5
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• pp.95-108
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• 2006

The digital contents expand into software source code and maintenance of technology and IPR about source code have a very important meaning to international competition, The recognition about software security is very low specially among these Intellectual Property Rights. On occurring disputation property, we have to prove the fact, there is a problem to discriminate the original source code, Also, it is hard to accurate decision that is correct to complexity and the lack of read and understand ability even if software is reproduced. In this paper, we don't enforce distinction about software reproduction by one individual code unit. And we developed digital license prototype of XML that can distinguish reproduction based on structural conformability of whole source codes. Software has Context Free Grammar in structure and presents BNF notation type, it is apt to present hierarchical structure. Then, we can express architecture of software source code by hierarchical structure to discriminate structural conformability. In this paper, we make a study of the digital licence prototype for discriminate the original source code. Reserved words of software source code by parsing express to XML file that have hierarchical structure. Then, we can express architecture of software source code by tree structure form instead of complex source code.

• KIISE Transactions on Computing Practices
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• v.21 no.2
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• pp.148-153
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• 2015

In our domestic software industries, it is focused on such a high quality development/ testing process, maturity measurement, and so on. But the real industrial fields are still working on a code-centric development. Most of the existing legacy systems did not keep the design and highly increased the code complexity with more patching of the original codes. To solve this problem, we adopt a code visualization technique which is important to reduce the code complexity among modules. To do this, we suggest a tool chaining method based on the existing open source software tools, which extends NIPA's Software Visualization techniques applied to procedural languages. In addition, it should be refactored to fix bad couplings of the quality measurement indicators within the code visualization. As a result, we can apply reverse engineering to the legacy code, that is, from programming via model to architecture, and then make high quality software with this approach.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.1
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• pp.30-35
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• 2013

Many function of railway signalling system which is in charge of most core function in a railway system are being operated by the software according to the development of computer technology. Accordingly, the source code testing to verify the safety of the railway signalling system software becomes to be more important, and related international standards highly recommend verifications on the source code also. For this reason, several related studies on vital source code verification were executed from several years ago in Korea. This paper performed tests through the application to railway signalling system being applied to the existing actual domestic railway sites through automated testing tools for coding rules of signalling system software and another signaling system software under development in Korea recently, and analyzed their results.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.9
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• pp.2074-2079
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• 1997

Much recent work has been done in the two related areas of source coding for data compression, and channel coding for data storage, respectively. We propose two (0, k) run-lengh limited(RLL) data compression codes for the storage that combine source and channel coding. It was shown that the propsoed codes approach the maximum code rate of (0, k) code as k increase. Thus, the overall code rate of storage system can be increased by using the combined source/channel coding as compared to the conventional 8/9 code which is popular in hard drive systems Functhermore, one can also reduce the complexity of modulation coding procedure by using already RLL constrained data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.4
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• pp.346-351
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• 2003

In spite of the size and complexity of software becomes large and complicated, the demand of rapid development, cost reduction, good productivity and good quality software is increasing in these days. Many methods were proposed for efficient software development such as various Case tools. Metrics, Process improvement model (CMM, SPICE, ISO9000) and etc. However, most of them we useful to manage the whole projects rather than an individual programming. In this paper, we introduced a system for quality assessment and complexity metrics for Java programs to assess the individual programmer's quality rather than team's quality. This system shows not only the metrics value for quality assessment but also the source code and the soucture of classes simultaneously.