• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.119-119
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• 2000

In this research an induction motor vector control system was developed using Simulink and RTW(Real Time Workshop). On the Simulink window, control system is designed in the form of block diagrams, program codes are produced automatically with the RTW, then c compiler compiles the program codes. With this automatic real time program producing mechanism rapid prototyping is realized without the time-consuming manual program coding procedures. To show effectiveness of the proposed designing scheme a DSP-based induction motor vector control system was constructed and implemented

• Journal of Korean Institute of Industrial Engineers
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• v.17 no.2
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• pp.17-26
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• 1991

This paper discusses an expert system to generate part codes and construct part families, ESPCC, for the group technology application. The ESPCC, that is developed by using VP-Expert rule-based expert system development tool, embodies the specific knowledge of human experts to determine part codes consistent with the OPITZ classification and coding system. The ESPCC is implemented on an IBM compatible personal computers running MS-DOS.

• Journal of Communications and Networks
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• v.17 no.6
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• pp.582-591
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• 2015

A massive distributed storage system is the foundation for big data operations. Access latency performance is a key metric in distributed storage systems since it greatly impacts user experience while existing codes mainly focus on improving performance such as storage overhead and repair cost. By generating parity nodes from parity nodes, in this paper we design new XOR-based erasure codes hierarchical tree structure code (HTSC) and high failure tolerant HTSC (FH HTSC) to reduce access latency in distributed storage systems. By comparing with other popular and representative codes, we show that, under the same repair cost, HTSC and FH HTSC codes can reduce access latency while maintaining favorable performance in other metrics. In particular, under the same repair cost, FH HTSC can achieve lower access latency, higher or equal failure tolerance and lower computation cost compared with the representative codes while enjoying similar storage overhead. Accordingly, FH HTSC is a superior choice for applications requiring low access latency and outstanding failure tolerance capability at the same time.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.11
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• pp.36-42
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• 2010

This paper presents a hybrid approach to the construction of quasi-cyclic (QC) low-density parity-check (LDPC) codes based on parallel bundles in Euclidean geometries and circulant permutation matrices. Codes constructed by this method are shown to be regular with large girth and low density. Simulation results show that these codes perform very well with iterative decoding and achieve reasonably large coding gains over uncoded system.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.121-127
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• 2013

When input power is small, nonideal symmetric balance incomplete block design(BIBD) code design is effective in the spectral-amplitude-code(SAC) optical code-division multiple-access (OCDMA) system. But the number of simultaneous users is not sufficient. To overcome this property, we propose 2-D BIBD codes, where nonideal BIBD codes are used as spectral code and ideal BIBD codes are used as spatial codes. Analytical results show that the number of simultaneous users increases significantly.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1647-1650
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• 2002

In this paper, a class of multi-level spreading codes, i.e., ternary ZCD(zero-correlation duration) spreading codes are introduced. Novel ternary ZCD code sets are generated by carrying out a chip-shift operation of the ternary preferred pairs (TPP) with a ZCD of(0.75N+1)chips. Ternary ZCD codes have superior family size than the binary ZCD codes and they are effective for approximately synchronized (AS) CDMA

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.1966-1973
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• 1999

In this paper, we introduce the concept of a HAPS(High Altitude Platform Station) system which is expected to be a next generation communication system and suggest several error correcting codes to provide high quality services. Since a HAPS system encounters serious signal attenuation due to rain and scattering in the air, concatenated codes which have a high coding gain is considered to be a proper error correcting method. In this paper, we provide performance analyses result of two candidate coding schemes for a HAPS. The first one is a conventional concatenated coding scheme, and the second one is a iterative decoding method known as Turbo Codes.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3526-3539
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• 2022

Nuclear thermal-hydraulic system analysis codes have been developed to simulate nuclear reactor systems, which solve simplified governing equations by replacing source terms with constitutive relations for simulating entire reactor systems with low computational resources. For half a century, many efforts have been made for wider versatility and higher accuracy of system codes, but various factors can affect the code analysis results, and it was difficult to isolate these factors and interpret them individually. In this study, two system codes, RELAP5 and TRACE, which have many users and are highly reliable, are selected to analyze only the effects of constitutive relations. The influence of constitutive relations is analyzed using in-house platforms that replicate constitute relations of RELAP5 and TRACE equally to exclude factors that may affect analysis results, such as governing equation solvers and user effects. Among the various constitutive relations, the analysis is performed on the wall variables expected to have the most influence on the analysis results. Part 1 paper presents the methodology and wall friction model comparison, while Part 2 paper shows wall heat transfer comparison of the two selected codes.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2488-2498
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• 2021

The wall film-wise condensation plays an important role in the heat transfer processes of heat exchangers, refrigerators, and air conditioner. In the field of nuclear engineering, steam condensation is often utilized in safety systems to remove the core decay heat under both transient and accident conditions. In particular, passive containment cooling system (PCCS), are designed to ensure containment safety under severe accident conditions. A computational fluid dynamics (CFD) scale analysis has been conducted to calculate the heat transfer rate of the PCCS. However, despite the increase in computing power, there are challenges in the long-term transient simulation of containment using CFD scale codes. In this study, a heat structure coupling between the CFD and system analysis codes was performed to efficiently analyze PCCS. In addition, the component unstructured program for interfacial dynamics (CUPID) was improved to analyze the condensation behavior of ternary gas mixtures. Thereafter, the condensation heat transfer on the primary side was calculated using the improved CUPID and CFD code, whereas that on the secondary side was simulated using MARS. Both the coupled codes were validated against the CONAN facility database. Finally, conjugate heat transfer simulations with wall condensation in the presence of non-condensable gases were appropriately performed.

• Convergence Security Journal
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• v.23 no.1
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• pp.55-61
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• 2023

QR Code is a two-dimensional code in the form of a matrix that contains data in a square-shaped black-and-white grid pattern, and has recently been used in various fields. In particular, in order to prevent the spread of COVID-19, the usage increased rapidly by identifying the movement path in the form of a QR code that anyone can easily and conveniently use. As such, Qshing attacks and damages using QR codes are increasing in proportion to the usage of QR codes. Therefore, in this paper, a system was implemented to block movement to harmful sites and installation of malicious codes when scanning QR codes.