• 한국융합학회논문지
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• 제4권4호
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• pp.21-29
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• 2013

2차원 QR Code는 1차원 바코드의 용량, 크기, 방향에 대한 한계를 개선하였으며, 방대한량의 데이터를 압축하여 저장할 수 있는 능력을 갖추고 많은 응용분야에서 사용되고 있다. 최근에는 QR Code를 인식할 수 있는 스마트 폰의 도입과 사용의 증대로 QR Code의 도입이 급속도로 확산되었다. 하지만 다양한 정보를 저장할 수 있는 QR Code의 디코딩 기술에 대한 구체적인 문서화가 없는 상태이다. 따라서 본 논문에서는 QR code의 인코딩에 따른 디코딩 과정에 대해 구체적인 처리 절차와 알고리즘을 제시하고 예를 통해 디코딩 과정을 상세히 이해시키는데 연구목적이 있다.

• 전자공학회논문지
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• 제50권5호
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• pp.121-127
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• 2013

작은 입력신호의 spectral-amplitude-code(SAC) optical code-division multiple-access (OCDMA) 시스템에는 nonideal symmetric balance incomplete block design(BIBD) code의 사용이 효율적이나 충분한 사용자를 수용하지 못하는 단점이 있다. 이를 극복하기 위하여 본 논문에서는 ideal BIBD code를 공간 코드로 사용하고 nonideal code를 파장 코드로 사용하는 two-dimensional(2-D) BIBD code를 제안한다. 사용자 수에 따른 bit error-rate(BER) 분석을 통하여 제안하는 2-D BIBD code가 1-D BIBD code에 비하여 최대사용자 수를 현저하게 증가시킬 수 있음을 알 수 있다.

• ETRI Journal
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• 제38권3호
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• pp.529-539
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• 2016

Recently, a product-matrix (PM) framework was proposed to construct optimal regenerating codes for homogeneous distributed storage systems (DSSs). In this paper, we propose an extended PM (EPM) framework for coding of heterogeneous DSSs having different repair bandwidths but identical storage capacities. Based on the EPM framework, an explicit construction of minimum remote-repair bandwidth regenerating (MRBR) codes is presented for a specific heterogeneous DSS, where two geographically different datacenters with associated storage nodes are deployed. The data reconstruction and regeneration properties of the MRBR code are proved strictly. For the purpose of demonstration, an example implementation of MRBR code is provided. The presented MRBR code is the first optimal strict-regenerating code for heterogeneous DSSs. In addition, our proposed EPM framework can be applied to homogeneous systems also.

• Journal of Ginseng Research
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• 제41권3호
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• pp.339-346
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• 2017

Background: In this study, we investigated how to convert the Panax ginseng DNA sequence code and chemical fingerprints into a two-dimensional code. In order to improve the compression efficiency, GATC2Bytes and digital merger compression algorithms are proposed. Methods: HPLC chemical fingerprint data of 10 groups of P. ginseng from Northeast China and the internal transcribed spacer 2 (ITS2) sequence code as the DNA sequence code were ready for conversion. In order to convert such data into a two-dimensional code, the following six steps were performed: First, the chemical fingerprint characteristic data sets were obtained through the inflection filtering algorithm. Second, precompression processing of such data sets is undertaken. Third, precompression processing was undertaken with the P. ginseng DNA (ITS2) sequence codes. Fourth, the precompressed chemical fingerprint data and the DNA (ITS2) sequence code were combined in accordance with the set data format. Such combined data can be compressed by Zlib, an open source data compression algorithm. Finally, the compressed data generated a two-dimensional code called a quick response code (QR code). Results: Through the abovementioned converting process, it can be found that the number of bytes needed for storing P. ginseng chemical fingerprints and its DNA (ITS2) sequence code can be greatly reduced. After GTCA2Bytes algorithm processing, the ITS2 compression rate reaches 75% and the chemical fingerprint compression rate exceeds 99.65% via filtration and digital merger compression algorithm processing. Therefore, the overall compression ratio even exceeds 99.36%. The capacity of the formed QR code is around 0.5k, which can easily and successfully be read and identified by any smartphone. Conclusion: P. ginseng chemical fingerprints and its DNA (ITS2) sequence code can form a QR code after data processing, and therefore the QR code can be a perfect carrier of the authenticity and quality of P. ginseng information. This study provides a theoretical basis for the development of a quality traceability system of traditional Chinese medicine based on a two-dimensional code.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2005년도 한국컴퓨터종합학술대회 논문집 Vol.32 No.1 (A)
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• pp.490-492
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• 2005

본 논문에서는 별도의 충돌 방지 메커니즘이 필요 없는 orthogonal code를 태그 ID로 부여함으로써 태그 인식을 간단하게 하는 메커니즘에 대해 설명한다. 첫 번째 적용 메커니즘으로 Local환경에서 Orthogonal code가 적용될 수 있는 여러 가지 응용 분야를 제안하고 두 번째로 Orthogonal code를 기존 ID 체계의 일부분으로 사용하여 anti-collision algorithm의 효율을 높이는 방법을 제시한다. 마지막으로 orthogonal code ID의 개수가 많아짐에 따라 code bit수가 길어지는 문제를 해결하기 위하여 code를 블록화 하여 사용 bit를 줄이는 메커니즘을 제시한다.

• 정보과학회 논문지
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• 제41권11호
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• pp.935-942
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• 2014

오늘날 소프트웨어는 규모가 크고 시장 출하 기간의 단축 상황에서도 고품질 이슈가 중요하다. 그리고 산업 현장에서는 빠른 개발을 위해 아직도 코드 중심 개발에 초점을 두고 있다. 따라서 1) 개발자의 나쁜 코드 개발 습관의 개선 측면 그리고 2) 소프트웨어 비설계화, 비문서화 및 코드 내부 구조 비가시화의 유지보수 측면 등을 해결해야 한다. 이에 코드 가시화의 필요성이 대두되고 있다. 본 논문에서는 객체지향 코드의 내부 구조 시각화 방법을 위해 Tool-Chain을 이용한 내부 구조 가시화 방법과 품질 개선 절차를 제안한다. 사례로써 NIPA의 SW Visualization 기법을 실제 객체 코드에 적용한다. 먼저 객체지향 코드의 모듈 단위를 클래스로 정의하고, 코드의 정량적 분석 및 가시화를 통해 코드의 복잡도(Code Complexity)를 줄이고자 하였다.

• 천문학회보
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• 제40권2호
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• pp.38.2-38.2
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• 2015

Development of a new code for magnetohydrodynamic (MHD) phenomena in fusion plasma is under progress through a collaboration between plasma physicists, mathematicians, and astrophysicists. The code employs approaches different from those of existing codes. For instance, it is based on a finite difference scheme of high-order and high accuracy, complying conservation laws. The new code will have characteristics distinguished from those of commonly used code such as M3D and NIMROD. Here we will report the progress of the code development.

• 대한수학회보
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• 제54권4호
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• pp.1095-1110
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• 2017

The t-wise intersection is a useful property of a linear code due to its many applications. Recently, the second author determined the t-wise intersection of a relative two-weight code. By using this result and generalizing the finite projective geometry method, we will present the t-wise intersection of a relative three-weight code and its applications in this paper.

• 대한수학회보
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• 제54권3호
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• pp.731-736
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• 2017

It is well-known that there exists a constant-weight $[s{\theta}_{k-1},k,sq^{k-1}]_q$ code for any positive integer s, which is an s-fold simplex code, where ${\theta}_j=(q^{j+1}-1)/(q-1)$. This gives an upper bound $n_q(k,sq^{k-1}+d){\leq}s{\theta}_{k-1}+n_q(k,d)$ for any positive integer d, where $n_q(k,d)$ is the minimum length n for which an $[n,k,d]_q$ code exists. We construct a two-weight $[s{\theta}_{k-1}+1,k,sq^{k-1}]_q$ code for $1{\leq}s{\leq}k-3$, which gives a better upper bound $n_q(k,sq^{k-1}+d){\leq}s{\theta}_{k-1}+1+n_q(k-1,d)$ for $1{\leq}d{\leq}q^s$. As another application, we prove that $n_q(5,d)={\sum_{i=0}^{4}}{\lceil}d/q^i{\rceil}$ for $q^4+1{\leq}d{\leq}q^4+q$ for any prime power q.

• Nuclear Engineering and Technology
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• 제46권5호
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• pp.655-666
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• 2014

The CUPID code has been developed at KAERI for a transient, three-dimensional analysis of a two-phase flow in light water nuclear reactor components. It can provide both a component-scale and a CFD-scale simulation by using a porous media or an open media model for a two-phase flow. In this paper, recent advances in the CUPID code are presented in three sections. First, the domain decomposition parallel method implemented in the CUPID code is described with the parallel efficiency test for multiple processors. Then, the coupling of CUPID-MARS via heat structure is introduced, where CUPID has been coupled with a system-scale thermal-hydraulics code, MARS, through the heat structure. The coupled code has been applied to a multi-scale thermal-hydraulic analysis of a pool mixing test. Finally, CUPID-SG is developed for analyzing two-phase flows in PWR steam generators. Physical models and validation results of CUPID-SG are discussed.