• 한국미생물·생명공학회지
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• 제13권4호
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• pp.383-389
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• 1985

전분을 발효할 수 있는 새로울 효모균수의 개발을 목적으로 PEG를 fusogen으로 사용하여 이속 효모간 원형질체 융합을 시도하였다. 원형질체 융합에 사용한 친균주의 genetic marker로는 상보적 영양요구성을 이용하였고 각각의 영양요구성이 상호보완되어 최소배지상에 자라는 colony를 융합체로하였다. S. cerevisiae와 C. tropicalis의 이속간 원형질체의 융합빈도는 $10^{-4}$에서 $10^{-6}$ 정도였으며, 원형질체 융합에 있어서 PEG 4,000. 30%가 가장 좋은 효과를 나타내었다. 최적 pH는 8.0이었으며, PEG의 처리효과는 온도가 상승함에 따라 증가하여 35$^{\circ}C$에서 최적을 나타내었고 또한 Ca이온의 첨가에 의해서도 증가하였는데 Ca 이온의 촉진효과는 1mM과 100mM 농도 사이에서 최고를 나타내었다.

• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1345-1356
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• 2021

Damage to nuclear power plants causes human casualties and environmental disasters. There are electrical facilities that control safety-related devices in nuclear power plants, and seismic performance is required for them. The 2016 Gyeongju earthquake had many high-frequency components. Therefore, there is a high possibility that an earthquake involving many high frequency components will occur in South Korea. As such, it is necessary to examine the safety of nuclear power plants against an earthquake with many high-frequency components. In this study, the shaking table test of electrical facilities was conducted against the design earthquake for nuclear power plants with a large low-frequency components and an earthquake with a large high-frequency components. The response characteristics of the earthquake with a large high-frequency components were identified by deriving the amplification factors of the response through the shaking table test. In addition, safety of electrical facility against the two aforementioned types of earthquakes with different seismic characteristics was confirmed through limit-state seismic tests. The electrical facility that was performed to the shaking table test in this study was a motor control center (MCC).

• 정보처리학회 논문지
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• 제13권2호
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• pp.41-47
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• 2024

시간 및 주파수 영역에서 각각 학습한 모델 간에 성능 차이가 발생할 경우, 앙상블을 수행하더라도 개별 모델 간의 성능 불균형으로 인하여 앙상블의 성능이 오히려 저하되는 현상을 확인할 수 있었다. 따라서, 본 논문은 시간 영역과 주파수 영역에서 특징을 추출하고, 이들을 융합한 단계적 학습 방법을 통해 파이프라인 누출 감지의 정확성을 높이기 위한 누출판별 기법을 제안한다. 이 방법은 두 단계의 학습 과정으로 이루어지며, 먼저, 단계 1에서는 시간 영역과 주파수 영역에서 독립적으로 모델 학습을 수행하여 도메인별로 주어진 데이터로부터 중요한 특징들을 효과적으로 추출하도록 하였다. 단계 2에서는 사전학습 완료된 각 모델로부터 해당 분류기를 제거한 후, 두 도메인의 특징들을 서로 융합하고 새로운 분류기를 추가하여 재학습을 수행하였다. 본 논문에서 제안하는 전이학습 기반 특징융합 기법은 시간 및 주파수 영역에서 추출된 특징들을 융합하여 모델 학습을 수행함으로써, 두 영역의 특징이 상호 보완적으로 작용하여 모델이 다양한 정보를 활용함으로 인해 99.88%의 높은 정확도를 달성하여 파이프 누수 감지에 있어 우수한 성능을 입증하였다.

• 한국산학기술학회논문지
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• 제6권1호
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• pp.94-103
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• 2005

고강도 저발포 스티로폼을 고온고압 수증기를 사용하지 않고 초고주파를 사용하여 제조하는 공법을 개발하였다. 주파수 13.6 MHz이고 출력 7kW의 전자기파와 3배 발포분을 원료로 사용하였다. 유전가열방식이 스팀방식보다 내부 융착성에서 우수하였으며, 모분 온도 $105-110^{\circ}C$에서 내부 융착성이 가장 우수하였다.

• 한국분말재료학회지
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• 제24권5호
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• pp.351-356
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• 2017

Tin dioxide nanoparticles are prepared using a newly developed synthesis method of plasma-assisted electrolysis. A high voltage is applied to the tin metal plate to apply a high pressure and temperature to the synthesized oxide layer on the metal surface, producing nanoparticles in a low concentration of sulfuric acid. The particle size, morphology, and size distribution is controlled by the concentration of electrolytes and frequency of the power supply. The as-prepared powder of tin dioxide nanoparticles is used to fabricate a gas sensor to investigate the potential application. The particle-based gas sensor exhibits a short response and recovery time. There is sensitivity to the reduction gas for the gas flowing at rates of 50, 250, and 500 ppm of $H_2S$ gas.

• 한국기계가공학회지
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• 제10권6호
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• pp.22-26
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• 2011

The application of fast tool servo (FTS) for diamond turning has been investigated extensively. This paper focuses on the fabrication of the sinusoidal microstructure on a roller, which generated by a piezoelectric-assisted FTS. The influence of the machining parameters on the microstructure configuration was investigated. The experiment results point out that the configuration of the machined microstructure depends mainly on the spindle speed, the diameter of roller and the driving frequency of FTS. The calculation method of the microstructure dimension was reported. The turning test results show that the diamond tool can be moved up to 1kHz without any reinjected vibration in the machining and the peak-to-valley amplitude of the machined sinusoidal microstructure is about 12<${\mu}m$

• Corrosion Science and Technology
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• 제9권1호
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• pp.8-11
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• 2010

During PEO (plasma-electrolytic-oxidation) treatment of titanium, the relationship between the thickness of oxide film and the measured electrical information was investigated. A simple real time monitoring method based on the electrical information being gathered during PEO treatment is proposed. The proposed method utilizes the current flowing from a high frequency voltage source to calculate the resistance of an oxide film, which is converted into the thickness of an oxide film. This monitoring method can be implemented in PEO system in which an oxide film is grown by constant or pulsed voltage/current sources.

• 미생물학회지
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• 제26권4호
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• pp.298-304
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• 1988

Antibiotic resistance plasmids (RP4, pMG1, R679 and R91-5) were used as primary selective markers to detect the fusants in Pseudomonas spp. By using plasmid marker, clones containing both plasmids of parental strains were obtained as fusants by direct selection. The spheroplast fusion was occured not only between strains of interspecies, but also between strains of intergenus such as Pseudomonas and E. coli. The frequencies of fusant formation were variable from $2.8\times 10^{-1}$ to $6.0\times 10^{-4}$ -4/. In addition, chromosomal recombinants were formed among the clones with both parental plasmids in frequencies of 0.44-1.3%. The fusant formation frequency between interspecies of intraspecies was not different markedly, but stability of plasmids in fusants correlated with the phylogenic smilarity of the parental strains.

• Journal of the Korean Physical Society
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• 제73권12호
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• pp.1873-1878
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• 2018

We have investigated the ionic conductivity and dielectric relaxation in $Li_2B_4O_7$ (LBO) and $Li_2O-B_2O_3-Ta_2O_5$ (LBTO) glasses. The sample was synthesized by using the melt quenching method. The frequency dependence of the electrical data from the LBO and LBTO glasses has been analyzed in the frameworks of the impedance Cole-Cole formalism and the universal power-law representation driven by the modified fractional Rayleigh equation. The potential barriers in the LBO and the LBTO glasses turn out to be the same. Comparing with the dc and ac activation energies of the LBO glass, these energies of the LBTO glass decrease due to the increasing Coulomb interaction of inter-cationic interaction.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권3호
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• pp.653-669
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• 2024

Dynamic scene deblurring is a complex computer vision problem owing to its difficulty to model mathematically. In this paper, we present a novel approach for image deblurring with the help of the sharp reference image, which utilizes the reference image for high-quality and high-frequency detail results. To better utilize the clear reference image, we develop an encoder-decoder network and two novel modules are designed to guide the network for better image restoration. The proposed Reference Extraction and Aggregation Module can effectively establish the correspondence between blurry image and reference image and explore the most relevant features for better blur removal and the proposed Spatial Feature Fusion Module enables the encoder to perceive blur information at different spatial scales. In the final, the multi-scale feature maps from the encoder and cascaded Reference Extraction and Aggregation Modules are integrated into the decoder for a global fusion and representation. Extensive quantitative and qualitative experimental results from the different benchmarks show the effectiveness of our proposed method.