• Journal of the Korean Society of Systems Engineering
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• v.17 no.1
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• pp.1-10
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• 2021

In this paper we proposed the alternative analysis of reliability design using redundancy technique. First, we presented the process for establishing the reliability design alternative analysis process considering the active redundancy and the standby redundancy. and then, the case analysis of A driving equipment was performed in accordance with the reliability design alternative analysis process presented. In case the series reliability design result is not met with the reliability target value. so, the target item for redundancy design of A driving equipment were selected as items with a severity of two or higher. The redundancy design applied with active and standby redundancy techniques were analyzed using BlockSim software. As a result, it was analyzed that reliability design to active redundancy with one of two elements required for A driving equipment is the most efficient compared to the target value of reliability. The results of this study can be usefully used before the reliability design is performed.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.11
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• pp.1132-1137
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• 2011

Critical systems with high reliability feature fault tolerant redundancy. Conventional analytical reliability analysis methods that use the Reliability Block Diagram do not adequately reflect characteristics of the redundancy management system and are not suitable for this applications. This paper uses Monte-Carlo method to calculate the reliability of complicated redundant systems. The method was first validated for cases with analytical solutions. Then, the tool was successfully applied to analyze reliability of the flight control systems with a voter as redundancy management system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.6
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• pp.595-601
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• 2009

A flight control system for high reliability consists of complicated redundant structures. This redundancy can improve fault tolerant characteristics of system. So, a system manager is able to choose a suitable structure using analyzed quantitative data of various redundant structures. In this paper, we analyzed redundant characteristics and reliability. We defined necessary mathematical model for analysis tool. Then we compose a reliability block diagram analysis tool applying such defined analysis model using Simulink blocks. Finally we verified the analysis tool using a commercial tool.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.293-296
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• 1996

In this paper, we studied two image characteristics, similarity and smoothness, which give rise to local and global redundancy in image representation. The similarty means that any patterns in the image repeat itself anywhere in the rest of image. The smoothness means that the gray level values within a given block vary gradually rather than abruptly. In this sense, we propose a lossless medical image compression scheme which exploits both types of redundancy. This method segments the image into variable size blocks and encodes them depending on characteristics of the block. The proposed compression schemes works better than other compression schemes such as the huffman, the arithmetic, the Lempel-Ziv and the lossless scheme of JPEG.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3104-3110
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• 2011

This paper describes how to ensure safety of train by guaranteeing stable and continuous communication in RF-CBTC. CBTC System uses the wireless communication between onboard and wayside so that safety of wireless communication is the most important. Losing the position of train causes vital problem of train service. By losing the position of train, the other trains are blocked in the block and the train move by emergency mode so headway and safety cannot guaranteed. Therefore, safety is ensured by redundancy of wireless equipment. One of the ways to make redundancy is redundancy of equipment. However, the redundancy of equipment spends a lot of money to avoid interference in limited place like underground. Continuous communication is guaranteed by means of redundancy of wireless communication coverage to solve the problems even though one of the equipment is broken.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.827-839
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• 2021

Due to climate change and population growth, water scarcity is getting worse all over the world. Among various methods for desalination of seawater, the Multi-Effect Adsorptive Desalination method, which combines the existing Multi-Effect Desalination method and the Adsorptive Desalination method and can produce high-concentration-high-concentration freshwater, is emerging. Because the Multi-Effect Adsorptive Desalination method combines the two different methods, the system becomes complicated and the possibility of failure increases. Therefore, in this study, availability analysis was performed on the Multi-Effect Adsorptive Desalination process. A total of four types of reliability block diagrams were presented, and availability analysis was conducted based on them. The first form of a reliability block diagram is configured in series without any redundancy. The availability of the reliability block diagram composed of the serial system was found to be lower than the required availability. In order to increase availability, the redundancy to pumps and boiler are added to system. As a result of availability analysis, it was confirmed that designing desalination systems with redundancy to pump meets the 93% availability, which is typically required availability for various plants.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.8
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• pp.662-668
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• 2013

Mobile communication systems have been adopting link adaptive transmission schemes such as adaptive modulation and coding (AMC) and hybrid-ARQ (HARQ). Incremental redundancy (IR) HARQ scheme is known to be highly efficient in terms of throughput and power consumption and can be a good solution for mobile communication systems. In this paper, we propose an IR-HARQ scheme based on dual-diagonal parity-type block LDPC codes in which we define a transmission priority of coded bits and propose the sub-packet construction rule. We present the throughput performance of IR-HARQ with various modulation and coding and multi-antenna modes. Consequently, the proposed scheme provides the improvement of system throughput by elaborate link adaptation with CQI information.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.12
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• pp.1022-1032
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• 2002

A multibit DRAM BIST methodology reducing redundancy programming overhead has been proposed. It is capable of counting and locating faulty bits simultaneously with the test. If DRAM cells are composed of n blocks generally, the proposed BIST can detect the state of no error, the location of faulty bit block if there is one error and the existence of errors in more than two blocks, which are n + 2 states totally, with only n comparators and an 3 state encoder. Based on the proposed BIST methodology, the testing scheme which can detect the number and locations of faulty bits with the errors in two or more blocks, can be easily implemented. Based on performance evaluation, the test and redundancy programming time of 64MEG DRAM with 8 blocks is reduced by 1/750 times with 0.115% circuit overhead.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2355-2364
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• 2012

Recently, the novel loop-up table(N-LUT) method to solve the tremendous memory problem of the conventional look-up table (LUT) method as well as to increase the generation speed of hologram patterns has been proposed. But, as the resolution of an input 3-D object is enhanced, the number of object points to be calculated for generation of its hologram pattern also increases, which results in a sharp increase of the computation time. Therefore, in this paper, a new approach for fast generation of the hologram pattern of 3-D object images is proposed by using the block redundancy feature of 3-D object images and the N-LUT method. Experimental results show that in the proposed method the number of object points and the overall computation time have been reduced by 43.3 % and 47.9 %, respectively compared to those of the conventional method for the case of the $5{\times}5$ block size. These good experimental results finally confirm the feasibility of the proposed method.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.121-124
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• 2001

For efficient transmission of 3DTV video signals, it is necessary to eliminate the inherent redundancy between the stereo image pairs. Though disparity estimation provides a powerful tool for eliminating the redundancy, it is very time consuming. This paper presents a novel disparity estimation scheme based on the human visual property. The disparity vectors of image blocks spatially adjacent to the current block are used as initial guesses fur the disparity vector of the current block. In addition, mixed-resolution coding is applied to reduce the computational complexity of disparity estimation. Through computer simulations on a stereoscopic sequence we show that the proposed method gives rise .to visually pleasing results with much reduced computational complexity.