• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.157-163
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• 2002

Consideration for parallel operation in a high power system has been increased due to the advantages of parallel operation like as high productivity, simplicity of design, and redundancy of power. This paper discussed the parallel operation of DC-DC Converter, Which Can be used as a high power system, is studied. Based on the small signal model of DC-DC Converter, the simple and exact power stage model of parallel operation system is derived and the parallel operation system using current balance method for the uniform current distribution among the parallel operation system is discussed. To verify the high performance of the proposed DC-DC converter system for parallel operation, the simulation test of the parallel operation, which has 2 Converter modules, is accomplished.

• 제어로봇시스템학회논문지
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• 제6권6호
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• pp.492-499
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• 2000

In this paper, realization techniques of the parallel processing and the parallel network system for image processing are described. The parallel image processing system is constructed by the characterization of image processing and processor. Several problems are solved to achieve effective parallel processing and processor networking with the particular properties of image processing, which are reduction of communication quantity, equalization of load and delay depreciation on communication. A parallel image input device is developed for the flexible networking of parallel image processing. An abnormal region detection algorithm which is the basic function in machine vision is applied to evaluate the constructed parallel image processing system. The performance and effectiveness of the system are confirmed by experiments.

• International Journal of Reliability and Applications
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• 제12권2호
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• pp.103-116
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• 2011

A series-parallel system with independent but non-identical components is considered. The expressions have been derived for the joint reliability importance (JRI) of m (${\geq}2$) components, chosen from a series-parallel system. JRIs of components of two different series-parallel systems are studied analytically and graphically.

• Industrial Engineering and Management Systems
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• 제4권2호
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• pp.117-122
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• 2005

An assembly system (AS), a valuable tool for mass production, is generally composed of a number of workstations and a transport system. While the workstations perform some preplanned operations, the transport system moves the assemblies by special designed pallets from one station to another. One common problem associated with automatic assembly systems is that some assembly operations may have relatively long cycle times. As a consequence, the productivity, as determined by the operations with the longest cycle time, can be reduced significantly. Therefore, special forms of parallel workstations were developed to improve the performance of an assembly system. In this paper, three most commonly used parallel stations: on-line, off-line and tunnel-gated stations in a free transfer assembly system are studied via discrete event simulation. Our findings revealed that the off-line parallel system has the best performance because the two independent parallel stations can lower the buffer requirement; reduce the sensitivity to variability of processing time and balance of a line. On-line parallel systems were found to have a relatively poor performance, because the operations of two parallel stations block each other, and higher buffer capacity is required to achieve similar capacity. The tunnel-gated system was more efficient than the on-line system since the first parallel station can operate independently. More importantly, we have quantified the productivity of the three different strategies mentioned. Engineers can choose the optimal strategies for installing parallel stations under their working environment.

• Journal of applied mathematics & informatics
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• 제5권2호
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• pp.277-284
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• 1998

The reliability and an estimate for it are derived for series-parallel and parallel-deries stress-strength model under assumption that all components are subjected to a common stress. We also obtain the asymptotic normal distribution of the estimate.

• 한국철도학회논문집
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• 제8권1호
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• pp.1-5
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• 2005

This paper has presented the parallel cyclic redundancy check (CRC) technique that performs CRC computation in parallel superior to the conventional CRC technique that processes data bits serially. Also, it has showed that the implemented parallel CRC circuit has been successfully applied to the inductively coupled passive RFTD system working at a frequency of 13.56㎒ in order to process the detection of logical faults more fast and the system has been verified experimentally. In comparison with previous works, the proposed RFID system using the parallel CRC technique has been shown to reduce the latency and increase the data processing rates about 15％ In the results. Therefore, it seems reasonable to conclude that the parallel CRC realization in the RFID system offers a means of maintaining the integrity of data in the high speed RFID system.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제1권1호
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• pp.119-124
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• 2001

In this pattern recognition on the large volumes of remote sensing satellite images, the inference time is much increased. In the case of the remote sensing data [5] having 4 wavebands, the 778 training patterns are learned. Each land cover pattern is classified by using 159, 900 patterns including the trained patterns. For the fuzzy classification, the 778 fuzzy rules are generated. Each fuzzy rule has 4 fuzzy variables in the condition part. Therefore, high performance parallel fuzzy inference system is needed. In this paper, we propose a novel parallel fuzzy inference system on T3E parallel computer. In this, fuzzy rules are distributed and executed simultaneously. The ONE_To_ALL algorithm is used to broadcast the fuzzy input to the all nodes. The results of the MIN/MAX operations are transferred to the output processor by the ALL_TO_ONE algorithm. By parallel processing of the fuzzy rules, the parallel fuzzy inference algorithm extracts match parallelism and achieves a good speed factor. This system can be used in a large expert system that ha many inference variables in the condition and the consequent part.

• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.1212-1220
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• 2013

In general, for a large power system like DC distribution system for buildings, several power converters are modularized for parallel operation. However, in parallel operation, inconsistency of parameters in each module causes circulating current in the whole system. Circulating current is directly related to loss, and, therefore, it is most important for the safety of the power system to supply the suitable current to each module. This paper proposes a control method to reduce circulating current caused during parallel operation. Accordingly, the validity of parallel operation system including response characteristics and normal state was verified by simulation and experiment result.

• 정보기술과데이타베이스저널
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• 제6권1호
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• pp.59-72
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• 1999

A study on workflow system as an automated business processing system is done recently. However, it did not consider various dependencies between parallel tasks. Therefore, this paper proposes modeling and verification of workflows with various parallel dependencies. For this, firstly, we propose four dependencies to specify various parallel dependencies between tasks. They contain sequential starts, parallel starts, sequential commits, and parallel commits. Secondly, we suggest a method to specify various parallel dependencies on workflow graph. Thirdly, we propose a verification method to detect contradictions on workflow specifications.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1235-1240
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• 2004

This paper has presented the parallel cyclic redundancy check (CRC) technique that performs CRC computation in parallel superior to the conventional CRC technique that processes data bits serially. Also, it has showed that the implemented parallel CRC circuit had been successfully applied to the inductively coupled passive RFID system working at a frequency of 13.56MHz in order to process the detection of logical faults more fast and the system had been verified experimentally. In comparison with previous works, the proposed RFID system using the parallel CRC technique has been shown to reduce the latency and increase the data processing rates in the results. Therefore, it seems reasonable to conclude that the parallel CRC realization in the RFID system offers a means of maintaining the integrity of data in the high speed RFID system.