• 한국정밀공학회지
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• 제21권12호
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• pp.84-91
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• 2004

A CCD camera with a laser stripe was applied to realize the automatic weld seam tracking in GMAW. It takes relatively long time to process image on-line control using the basic Hough transformation, but it has a tendency of robustness over the noises such as spatter and arc tight. For this reason, it was complemented with adaptive Hough transformation to have an on-line processing ability for scanning specific weld points. The adaptive Hough transformation was used to extract laser stripes and to obtain specific weld points. The 3-dimensional information obtained from the vision system made it possible to generate the weld torch path and to obtain the information such as width and depth of weld line. In this study, a neural network based on the generalized delta rule algorithm was adapted for the process control of GMA, such as welding speed, arc voltage and wire feeding speed.

• International Journal of Korean Welding Society
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• 제3권2호
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• pp.46-52
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• 2003

The refinement of microstructure and phase transformation near the interface of pure copper/carbon steel dissimilar metals joints with various friction welding parameters have been studied in this paper. The microstructure of copper and carbon steel joints were changed to be a finer grain compared to those of the base metals due to the frictional heat and plastic deformation. The microstructure of copper side experienced wide range of deformed region from the weld interface and divided into very fine equaxied grains and elongated grains. Especially, the microstructures near the interface on carbon steel were transformed from ferrite and pearlite dual structure to fine ferrite, grain boundary pearlite and martensite due to the welding thermal cycle and rapid cooling rate after welding. These microstructures were varied with each friction welding parameters. The recrystallization on copper side is reason for softening in copper side and martensite transformation could explain the remarkable hardening region in carbon steel side.

• 한국분말재료학회지
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• 제18권6호
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• pp.496-501
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• 2011

In this study, the effect of milling time on the microstructure and phase transformation behaviors of Ni-12 wt.%B powders was investigated using vibratory ball milling process. X-ray diffraction patterns showed that the phase transformation of mixed Ni-B elemental powder occurred after 50 hours of milling, with a formation of nickel boride phases. Through the study of microstructures in mechanical alloying process, it was considered that ball milling strongly accelerates solid-state diffusions of the Ni and B atoms during mechanical alloying process. The results of X-ray photoelectron spectroscopy showed that most of B atoms in the powder were linked to Ni with a formation of nickel boride phases after 200 hours of milling. It was finally concluded that mechanical alloying using ball milling process is feasible to synthesize fine and uniform nickel boride powders.

• Journal of Plant Biotechnology
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• 제7권4호
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• pp.219-223
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• 2005

We investigated chemical-wounding effect on Agrobacterium-mediated Chinese cabbage transformation via vacuum infiltration. Pre-germinated or germinating Chinese cabbage seeds were infiltrated with Agrobacterium tumefaciens LBA4404 cells carrying either GUS gene (pBI121) or hepatitis B virus surface antigen DNA (pBIHBsAg). Prior to agroinfiltration process, the seeds were soaked in sodium hydrosulfite (SHS) solution or just in sterile water as a control. Comparative transformation efficiency was determined by both of histochemistry and ELISA. We could demonstrate that SHS solution treatment especially to 1-day or 2-days old germinating seeds efficiently improved transformation process, and therefore, transient expression level. This strongly indicated that Agrobacterium infection could be facilitated indeed by SHS-causing wounds on Chinese cabbage seeds.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1507-1509
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• 1997

Property of insulation of electric machine is severely affected by process of electrical tree growing. Partial discharges(PD) have been used to determine degradation of insulations. In this paper, PD quantities detected and analyzed are PD magnitudes, repetition rates, phase angle distribution of PD pulses, and wavelet transformation. The wavelet transformation is an extended method of fourier transformation. The fourier transformation is a powerful tool for signal analysis, but it can't include informations for time. However the wavelet transformation analysis can include on the informations of time and frequencies at the same time. This paper discusses correlation between process of electrical tree growing and characteristics of PD in LDPE specimens.

• 경영과정보연구
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• 제15권
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• pp.223-244
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• 2004

E-business is one of business innovations to get competitive advantage over other competing companies by utilizing information technology which can make to enhance the efficiencies and effectiveness through connecting one or several value activities. E-transformation is the process of business innovation to trans brick and motor companies to brick and click companies to accomodate e-business environments by means of digitalizing business strategy, business system, business process, and company cultures. In this results, the company can develop entirely new value chain of business and render enhanced services to customers. In this paper, I will represent several e-transformation evaluation models which are used to realize e-transformation(trans from brick and motor companies to brick and click companies). Also, I propose the strategic thrust model, which is composed of strategic targets (customer, suppliers, partners) and strategic tools(technology innovation, integration). This model is differentiated with evaluation models in that it can capture the rapidly changing business environments, especially strategic targets(customers, suppliers, partners).

• 문화기술의 융합
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• 제7권1호
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• pp.545-550
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• 2021

본 논문에서는 기업의 디지털 전환을 위한 여러 목표 중에서 로보틱스 프로세스 자동화를 위한 대학 교육과정을 개발한다. ICT 기술의 발전과 4차 산업혁명의 과정에서 기존의 아날로그 정보들은 이산화, 디지털화, 디지털 전환의 단계를 거쳐 변화해 왔다. 최근 디지털 전환은 기존의 산업 시스템과 비즈니스의 패러다임을 변화시키는 파괴적 혁명에 따른 필수적인 생존 전략으로 언급되고 있다. 이는 기업이 새로운 비즈니스 모델, 제품 및 서비스를 창출하기 위해 디지털 역량을 활용함으로써 고객 및 시장의 파괴적인 변화에 적응하거나 이를 추진하는 지속적인 프로세스로 정의되고 있는데 이를 위해 기업이나 단체의 프로세스 자동화가 중요한 요소로 자리 잡고 있다. 따라서 이러한 변화에 따른 대학에서의 로보틱스 프로세스 자동화를 위한 교육과정의 필요가 제기되고 있어 기업체를 중심으로 이루어져 왔던 관련 교육 내용을 대학교를 위한 교육과정으로 도입하기 위해 재설계하였다. 교육과정은 수강생들이 오토메이션 애니웨어의 이센셜 또는 고급 자격증을 취득할 수 있도록 구성되었다.

• 한국통신학회논문지
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• 제27권3A호
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• pp.231-239
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• 2002

본 논문은 반복적인 부호화 과정을 수행함으로써 준최적 변환 (sub-optimal transformation)을 얻을 수 있는 새로운 프랙탈 부호화 기법에 대해 기술한다. 최적 변환 (optimal transformation)은 원영상과 가장 가까운 끌개(attractor)를 생성시키는 변환으로 정의될 수 있다. 불행히도, 최적 변환을 찾는 것은 과다한 계산량으로 인해 실제적으로 불가능한 것으로 알려져 있다. 그러나, 본 논문에서는 프랙탈 변환 및 끌개에 관련된 몇 가지 새로운 정리들을 통해 특수한 경우에 대해 최적 변환을 얻을 수 있을 뿐만 아니라 좀 더 일반적인 경우에 대해서는 준최적 변환을 얻을 수 있음을 보인다. 그 정리들에 기초한 제안된 방법은 복호화 시 수행하는 반복적인 과정과 유사한 과정을 수행함으로써 준최적 변환을 얻는다. 그래서 제안된 방법은 계산량이 많아지는 단점을 가지지만 복원화질 면에서 우수한 특징을 가진다. 실제 영상에 대한 실험결과는 제안된 방법이 최적 방법에 가까우며, 기존의 방법에 비해 우수함을 입증한다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.226-229
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• 2008

Hot press forming is an advanced forming technology fur manufacturing of complex and crash-resistant automotive parts using ultra high strength steels. The 3-dimensional FE analysis of hot press forming process, in which process the deformation, heat transfer and phase transformation behavior are fully coupled, is carried out. The vast amount of material properties for the FE analysis is obtained from material properties calculation software which is based on thermodynamic calculations. The overall methodology for the FE analysis of HPF process and the analysis results are discussed here.

• 한국초등수학교육학회지
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• 제16권3호
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• pp.427-450
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• 2012

학생들이 사고를 조직하고 문제를 해결하며 의사소통을 하는 데 표상의 사용은 필수적이다. 본 연구는 초등학교 6학년 학생들이 수학적 문제를 해결하는 과정에서 나타내는 표상과 상호작용을 통한 표상의 변환과정을 분석함으로써, 학생들의 수학적 표상을 바르게 이해하고 올바른 표상 지도를 위한 시사점을 얻으려 하였다. 분석 결과 학생들은 한 가지 표상 방법보다는 두세 가지의 표상 방법을 사용하며, 학생-학생 간, 교사-학생 간의 상호작용은 표상의 정교화에 긍정적으로 영향을 주는 것으로 나타났다.