• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.366-367
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• 2011

The DC distribution system iis a new promising topologies in a field of future smart distribution system. This system has high efficiency and reliability. So it is expected that there would be an increase in the installation of DC distribution systems. In this paper, the parameter of the DC/DC converter impact on customer's the power quailty in the DC distribution system when the fault occurred. For the analysis, DC network to be modeled using PSCAD/EMTDC. The fault is occurred at phase A in secondary side of MTR which is AC system. Then compared voltage and power at the customer side by varying the capacity of capcitor in the DC/DC converter.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.350-353
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• 1991

This study develops an expert system which solves the problems of the MTr/feeder overloads and the feeder constraints in automated radial distribution systems. Then, the objective is to perform the network reconfiguration by switching the tie and sectionalizing switches which eliminates the system violation, while achieving the load balance of the MTrs/feeders. To reduce the search space, an expert system based on heuristic rules is presented, and implemented in AI language Prolog. This system adopts the best-first tree search technique. The computational results are also prepared to show the performance of the heuristic algorithm developed.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1885-1887
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• 2000

In this paper we introduce preventative and diagnostic systems developed to prevent substations from accidental fault of electric power transmitting apparatus. We propose monitoring and diagnostic system for ultra high voltage GIS and main transformer of 765kV substations as an example of preventative and diagnostic techniques being applied in Korea. We also present a guideline to construct and manage an expert system for this purpose. Finally, an engineering solution as a substation management support system is proposed.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.198-200
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• 2001

In this paper, we describe the developed learning tool of expert system for preventive diagnosis of substation power equipments. The expert system was programmed by using the diagnosis methods as like gas analysis in oil and partial discharge, hottest temperature, the current of OLTC driving meter, the current of fan and pump in MTr and driving coil current in GCB and leakage current in LA. The learning tool is composed of the expert system and the explanation of diagnosed examples and the applied rules and it well worked according to the rule.

• International Journal of Quality Innovation
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• v.6 no.2
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• pp.116-130
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• 2005

While there are many successful cases where application of the TQM model has reaped substantial benefits (Corcoran, 1996; Hayday, 1996 and Massey, 1996), there is little attempt to further develop the TQM model to meet organisations' development needs. The purpose of this paper is introduce the process of development of a fit-for-purpose management system model to meet the development needs of the MTR Corporation Limited, a metro company of Hong Kong. The new management system model is formulated based on the previous research results, on TQM but comprises a new approach to bridging their pitfalls. The formulation of the TMS elements is based on the common factors of four National Quality Awards (Japan, USA, Europe and Australia) and the critical factors developed by seven studies. These studies include those of Saraph et al. (1989), Flynn et al. (1994), Anderson et al. (1995), Powell (1995), Handfield and Ghosh (1995), Black and Porter (1996), and Ahire et al. (1996).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2089-2094
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• 2009

The fault current has increased due to growth of distributed generations for the large power demand in power distribution system. To solve some problem such as excess of the circuit breaker's cut-off ratings, the superconducting fault current limiter(SFCL) has been progressed. However, the operational characteristics of the relay is changed by SFCL. Therefore, the proper impedance for the SFCL should be selected to keep protective coordination with the SFCL when SFCL is introduced on the neutral line of main transformer in distribution system. In this paper, the proper normal conducting resistance was suggested to solve the problem in case of the protection coordination with SFCL.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.275-277
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• 2001

In this paper a preventative and diagnostic system for high and ultra high voltage electric power transmission apparatus is proposed to secure substation normal operation. The proposed system consists of monitoring sub-system and diagnostic sub-system, which are mainly for GIS and main transformer, and the system will be applied for newly established 765kV class substation in Korea. Some guideline for combination with substation control system are presented, and engineering solution as an improved substation automation system is also proposed.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1413-1418
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• 2003

In this study, the topology optimization is applied to the design of a piezoelectric microactuator satisfying the specific mean transduction ratio(MTR). The optimization problem is formulated to minimize the difference between the specified and the current mean transduction ratio. In order to analyze the response of the piezoelectric-structure coupled system, both the structural and the electric potential are considered in the finite element method. The optimization problem is resolved by using Sequential Linear Programming(SLP) and the results of test problems show that the design of a piezoelectric microactuator with specified mean transduction ratio can be obtained.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.2
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• pp.206-213
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• 2004

In this study, the topology optimization is applied to the design of a piezoelectric microactuator satisfying the specific mean transduction ratio(MTR). The optimization problem is formulated to minimize the difference between the specified and the current mean transduction ratio. In order to analyze the response of the piezoelectric-structure coupled system, both the structural and the electric potential are considered in the finite element method. The optimization problem is resolved by using Sequential Linear Programming(SLP) and the results of test problems show that the design of a piezoelectric microactuator with the specified mean transduction ratio can be obtained.

• Molecules and Cells
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• v.40 no.9
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• pp.632-642
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• 2017

The DevSR (DosSR) two-component system, which is a major regulatory system involved in oxygen sensing in mycobacteria, plays an important role in hypoxic induction of many genes in mycobacteria. We demonstrated that overexpression of the kinase domain of Mycobacterium tuberculosis (Mtb) PknB inhibited transcriptional activity of the DevR response regulator in Mycobacterium smegmatis and that this inhibitory effect was exerted through phosphorylation of DevR on Thr180 within its DNA-binding domain. Moreover, the purified kinase domain of Mtb PknB significantly phosphorylated RegX3, NarL, KdpE, TrcR, DosR, and MtrA response regulators of Mtb that contain the Thr residues corresponding to Thr180 of DevR in their DNA-binding domains, implying that transcriptional activities of these response regulators might also be inhibited when the kinase domain of PknB is overexpressed.