• Journal of Korean Society of Industrial and Systems Engineering
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• v.16 no.27
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• pp.83-89
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• 1993

In order to model the Group Technology Problem three formulations are used, that is, generally the following formulations are used: (1) Matrix formulation, (2) Mathematical programming formulation, (3) Graph formulation. In the case of Matrix formulation, it is difficult to discribe the situation using the multi-job machine. But this paper proposed the model of Group Technology using the multi-job machin, taking the method of making practical application of principle of similarity coefficient.

• Bulletin of the Korean Mathematical Society
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• v.51 no.6
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• pp.1605-1614
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• 2014

In continuation to the investigation initiated by Ferraz, Goodaire and Milies in [4], we provide an explicit description for the Wedderburn decomposition of finite semisimple group algebras of the class of finite groups G, such that $$G/Z(G){\simeq_-}C_2{\times}C_2$$, where Z(G) denotes the center of G.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.615-615
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• 2006

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.303-306
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• 2003

최근 정보통신시장이 성숙기에 도달함에 따라, 기존 통신을 기반으로 한 타 분야와의 통합 또는 융합에 대한 관심이 매우 높다. 그 중 유무선 통합은 종래에는 분리된 영역이라고 여겨왔던 유선과 무선 영역이 서로 부분적으로 또는 단계적으로 연결, 공유 또는 통합되는 현상이다. 본 논문에서는 유무선 통합 서비스에 대한 개념과 국내외의 유무선 통합 서비스 현황을 살펴보고 향후 발전방향을 논한다.

• Proceedings of the SAREK Conference
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• 2003.07a
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• pp.246-246
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• 2003

• Journal of Welding and Joining
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• v.30 no.4
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• pp.10-13
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• 2012

• Molecules and Cells
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• v.27 no.5
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• pp.577-582
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• 2009

The development of a high-throughput functional genomic screening provides a novel and expeditious approach in identifying critical genes involved in specific biological processes. Here we describe a cell-based cDNA screening system to identify the transcription activators of BiP, an endoplasmic reticulum (ER) chaperone protein. BiP promoter contains the ER stress element which is commonly present in the genes involved in unfolded protein response (UPR) that regulates protein secretion in cells. Therefore, the positive regulators of BiP may also be utilized to improve the recombinant protein production through modulation of UPR. Four BiP activators, including human UDP-glucose:glycoprotein glucosyltransferase 1 (HUGT1), are identified by the cDNA screening. Overexpression of HUGT1 leads to a significant increase in the production of recombinant erythropoietin, interferon ${\gamma}$, and monoclonal antibody in HEK293 cells. Our results demonstrate that the cDNA screening for BiP activators may be effective to identify the novel BiP regulators and HUGT1 may serve as an ideal target gene for improving the recombinant protein production in mammalian cells.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.521-523
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• 2010

Reseatch and Analysis on the DGPS radiobeacon propagation measurement of Domestic ferry lines Starting with maritime DGPS Base stations of Palmido, Ochongdo which have been operated since 1999, truly our nation has become the most powerful country possessed with total of 17 DGNSS base stations in the field of DGNSS operation infrastructure. This paper intents to consider the development direction of the country's DGNSS services as identifying the services range of the maritime DGPS base stations in the south coast domestic ferry lines which sections are Busan$\rightarrow$Jeju, Jeju$\rightarrow$Nokdong.

• Journal of Korea Foundry Society
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• v.38 no.1
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• pp.9-15
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• 2018

Electromagnetic continuous casting (EMCC) was used to fabricate Ti-6Al-4V alloys with properties suitable for medical applications. Ti-6Al-4V alloy ingots fabricated by EMCC were subjected to heat treatment, such as residual stress removing (RRS), furnace cooling after solution treatment (ST-FC) and water-cooling after solution treatment (ST-WC), in order to obtain characteristics suitable for the standard. After component analysis, the microstructure and mechanical properties (tensile strength and elongation) were evaluated by ICP, gas analysis, OM, SEM, a Rockwell hardness tester and universal testing machine. The Ti-6Al-4V alloy ingot fabricated by EMCC was fabricated without segregation, and the lamellar structure was observed in the RRS and ST-FC specimens. The ST-WC specimen showed only martensite structure. As a result of evaluating the mechanical properties based on the microstructure results, we found that the water-cooled heat treatment condition after the solution treatment was most suitable for the Ti-6Al-4V ELI standard.

• Journal of the Optical Society of Korea
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• v.19 no.6
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• pp.687-694
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• 2015

A photoluminescence (PL) imaging method using a vision camera was employed to inspect InGaN/GaN quantum-well light-emitting diode (LED) epi-wafers. The PL image revealed dark spot defective regions (DSDRs) as well as a spatial map of integrated PL intensity of the epi-wafer. The Shockley-Read-Hall (SRH) nonradiative recombination coefficient increased with the size of the DSDRs. The high nonradiative recombination rates of the DSDRs resulted in degradation of the optical properties of the LED chips fabricated at the defective regions. Abnormal current-voltage characteristics with large forward leakages were also observed for LED chips with DSDRs, which could be due to parallel resistances bypassing the junction and/or tunneling through defects in the active region. It was found that the SRH nonradiative recombination process was dominant in the voltage range where the forward leakage by tunneling was observed. The results indicated that the DSDRs observed by PL imaging of LED epi-wafers were high density SRH nonradiative recombination centers which could affect the optical and electrical properties of the LED chips, and PL imaging can be an inspection method for evaluation of the epi-wafers and estimation of properties of the LED chips before fabrication.