http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Bac Xuan Nguyen,D. Mahinda Vilathgamuwa,Gilbert Foo,Peng Wang,Andrew Ong 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6
LCL network is one of the best choices for compensating bidirectional inductive power transfer (BIPT) systems. However, H ? Bridge power converter of the conventional BIPT systems generates highly distorted AC current which results in reduced overall system efficiency particularly in high power BIPT systems. In order to overcome this drawback, a multilevel converter (MC) with selective harmonic distortion (SHE) modulation method is presented in this paper to eliminate high order harmonic components in converter voltages at both sides of BIPT systems. The proposed MC topology is constructed using a modified H ? Bridge converter with minimum number of power switches. The proposed topology is suitable for low to medium power applications. The simulation results demonstrate the feasibility of the proposed scheme.
One-step Physical Method for Synthesis of Cu Nanofluid in Ethylene Glycol
Bac, L.H.,Yun, K.S.,Kim, J.S.,Kim, J.C.,Rhee, C.K. The Korean Powder Metallurgy Institute 2010 한국분말재료학회지 (KPMI) Vol.17 No.6
The Cu nanofluid in ethylene glycol was prepared by electrical explosion of wire, a novel one-step method. The X-ray diffraction, field emission scanning electron microscope and transmission electron microscope were used to study the properties of Cu nanoparticles. The results showed that the nanoparticles were consisted of pure face-centered cubic structure and near spherical shape with average grain size of 65 nm. Ultraviolet-visible spectroscopy (UV-Vis) confirmed Cu nanoparticles with a single absorbance peak of Cu surface plasmon resonance band at 600 nm. The nanofluid was found to be stable due to high positive zeta potential value, +51 mV. The backscattering level of nanofluid in static stationary was decreased about 2% for 5 days. The thermal conductivity measurement showed that Cu-ethylene glycol nanofluid with low concentration of nanoparticles had higher thermal conductivity than based fluid. The enhancement of thermal conductivity of nanofluid at a volume fraction of 0.1% was approximately 5.2%.
Characterization and Stability of Silver Nanoparticles in Aqueous Solutions
Bac, L.H.,Gu, W.H.,Kim, J.C.,Kim, B.K.,Kim, J.S. The Korean Powder Metallurgy Institute 2012 한국분말재료학회지 (KPMI) Vol.19 No.1
In this work, the silver nanoparticles have been synthesized by electrical explosion of wire in three liquid mediums: deionized water (DIW), polyvinylpyrrolidone (PVP) and sodium dodecyl benzene sulfonate (SDBS) solutions. Absorption in the UV-visible region of these suspensions was measured in the range of 300-800 nm. A surface plasmon peak was observed at ~400 nm in all suspensions in measured wavelength range. Particle size was analyzed by transmission electron microscope. It showed that the particles had nearly spherical shape in all samples. The average particle sizes prepared in DIW, PVP and SDBS solution were 37, 31 and 27 nm, respectively. Stability of the suspensions was estimated by multiple light scattering method. The presence of PVP and SDBS surfactants in the exploding medium resulted in enhanced stability of the silver suspensions.
Preparation and Stability of Gold Colloid by Electrical Explosion of Wire in Various Media
Bac, L. H.,Yun, G. S.,Kim, J. S.,Choi, H. S.,Kim, J. C. American Scientific Publishers 2011 Journal of Nanoscience and Nanotechnology Vol.11 No.2
<P>Gold colloids were prepared by electrical explosion of wire in various media: cold water (0 degrees C), room temperature water (25 degrees C), hot water (80 degrees C), 0.01 M polysorbate surfactant 20 (TW 20) solution, mixture of 0.01 M TW 20 and 0.01 M ascorbic acid. The size distribution of nanoparticles measured by transmission electron microscope was found to shift to a smaller size with a decrease of temperature and a presence of TW 20 surfactant. The multiple light scattering results showed that medium temperature and ambient medium of explosion process is much influence on the stability of colloid. The gold colloid prepared in cold water is unstable in comparison with one prepared in warm and hot water. The best stability of gold colloid obtained with explosion medium of TW 20 and ascorbic acid solution.</P>
Bac Tran Le,Jung-Eun Park 한국예방수의학회 2023 예방수의학회지 Vol.47 No.4
Previous studies have shown that proline mutations in the heptad repeat region stabilize the coronavirus spike (S) protein in a pre-fusion state. To understand the impact of proline substitutions on the fusogenicity of the S protein, we engineered the swine acute diarrhea syndrome coronavirus (SADS-CoV) S protein with two proline substitutions (S-PP) and examined its fusogenicity using dual-split-protein based cell-cell fusion assay. Unlike the wild-type S (S-WT), S-PP rarely formed syncytia. Additionally, protein expression of S-PP was impaired compared to S-WT, as previously reported. Our results indicate that pre-fusion stabilized S protein is unable to induce membrane fusion and provide a better understanding of SADS-CoV S and vaccine antigen design.
Sketch Recognition Using LSTM with Attention Mechanism and Minimum Cost Flow Algorithm
Bac Nguyen-Xuan,이귀상 한국콘텐츠학회 2019 International Journal of Contents Vol.15 No.4
This paper presents a solution of the ‘Quick, Draw! Doodle Recognition Challenge’ hosted by Google. Doodles are drawings comprised of concrete representational meaning or abstract lines creatively expressed by individuals. In this challenge, a doodle is presented as a sequence of sketches. From the view of at the sketch level, to learn the pattern of strokes representing a doodle, we propose a sequential model stacked with multiple convolution layers and Long Short-Term Memory (LSTM) cells following the attention mechanism [15]. From the view at the image level, we use multiple models pre-trained on ImageNet to recognize the doodle. Finally, an ensemble and a post-processing method using the minimum cost flow algorithm are introduced to combine multiple models in achieving better results. In this challenge, our solutions garnered 11th place among 1,316 teams. Our performance was 0.95037 MAP@3, only 0.4% lower than the winner. It demonstrates that our method is very competitive. The source code for this competition is published at: https://github.com/ngxbac/Kaggle-QuickDraw.