• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.2
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• pp.139-146
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• 2009

In this study, an assessment is made for the helicopter vibration reduction of composite rotor blades using an active twist control concept. The piezoceramic shear actuation mechanism along with elastic couplings of composite blades is used for vibration reduction. The rotor blades are modeled as composite box-beams with actuator layers bonded on the outer surfaces of the thin-walled section. The governing equations of motion for helicopter blades are obtained using Hamilton's principle. A time domain unsteady aerodynamic theory with free wake model is used to obtain the airloads. Various rotor configurations with different elastic couplings with appropriate actuator placement are used to investigate the hub vibration characteristics. Numerical results show that a substantial reduction of $N_b$/rev hub vibration can be achieved using the optimal control algorithm.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.13-22
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• 2021

The clinical decision support system uses accumulated medical data to apply an AI model learned by machine learning to patient diagnosis and treatment prediction. However, the existing black box-based AI application does not provide a valid reason for the result predicted by the system, so there is a limitation in that it lacks explanation. To compensate for these problems, this paper proposes a system model that applies XAI that can be explained in the development stage of the clinical decision support system. The proposed model can supplement the limitations of the black box by additionally applying a specific XAI technology that can be explained to the existing AI model. To show the application of the proposed model, we present an example of XAI application using LIME and SHAP. Through testing, it is possible to explain how data affects the prediction results of the model from various perspectives. The proposed model has the advantage of increasing the user's trust by presenting a specific reason to the user. In addition, it is expected that the active use of XAI will overcome the limitations of the existing clinical decision support system and enable better diagnosis and decision support.

• Current Photovoltaic Research
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• v.2 no.4
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• pp.177-181
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• 2014

$Cu_2ZnSn(S_xSe_{1-x})_4$ (CZTSSe) absorber thin films were prepared on Mo coated soda lime glass substrates by sulfo-selenization of sputtered stacked Zn-Sn-Cu precursor thin films. The Zn-Sn-Cu precursor thin films were sulfo-selenized inside a graphite box containing S and Se powder using rapid thermal processing furnace at $540^{\circ}C$ in Ar atmosphere with pre-treatment at $300^{\circ}C$. The effect of different S/Se ratio on the structural, compositional, morphological and electrical properties of the CZTSSe thin films were studied using XRD (X-ray diffraction), XRF (X-ray fluorescence analysis), FE-SEM (field-emission scanning electron microscopy), respectively. The XRD, FE-SEM, XRF results indicated that the properties of sulfo-selenized CZTSSe thin films were strongly related to the S/Se composition ratio. In particular, the CZTS thin film solar cells with S/(S+Se)=0.25 shows best conversion efficiency of 4.6% ($V_{oc}$ : 348 mV, $J_{sc}$ : $26.71mA/cm^2$, FF : 50%, and active area : $0.31cm^2$). Further detailed analysis and discussion for effect of S/Se composition ratio on the properties CZTSSe thin films will be discussed.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.421-431
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• 2021

It has been suggested that some toothpastes have the potential to promote hair growth. However, there was no scientific verification on the hair growth effect of toothpaste and no scientific report on major active ingredients in toothpaste. In this work, toothpaste and its constituents were applied topically over the shaved skin of C57BL/6 mice and evaluated. Results indicated that toothpaste showed hair growth effect. Also, the effect of toothpaste constituents on the proliferation rate of keratinocyte cells was investigated. The mixture solution of 𝛼-tocopherol acetate, l-menthol, and stevioside, each of that was known to promote hair growth and other toothpaste constituents were applied topically on mouse skin. When the mixture solution was included, hair growth effect was observed in mice. Transcriptome analysis was performed using the dorsal epidermis of mice from the group treated with toothpaste, the mixture which are presumed to be active ingredients for hair growth, and from mice used for the control group. As a result of analyzing the genes whose expression was significantly changed in each treatment group, the gene patterns of the two groups were very similar. Also, when functional genomic analysis was performed, genes with functions related to hair growth regulation showed a high extent of the change in both groups. Hair growth-related genes whose expression was changed in both groups included keratin, keratin-related proteins, forkhead box, and sonic hedgehog. Therefore, the hair growth effect of toothpaste is thought to be due to the effect of a mixture of 𝛼-tocopherol acetate, l-menthol, and stevioside.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.86.2-86.2
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• 2015

Cu2ZnSn(S,Se)4 thin film solar cells have been fabricated using sputtered Cu/Sn/Zn metallic precursors on Mo coated sodalime glass substrate without using a toxic H2Se and H2S atmosphere. Cu/Sn/Zn metallic precursors with various thicknesses were prepared using DC magnetron sputtering process at room temperature. As-deposited metallic precursors were sulfo-selenized inside a graphite box containing S and Se pellets using rapid thermal processing furnace at various sulfur to selenium (S/Se) compositional ratio. Thin film solar cells were fabricated after sulfo-selenization process using a 65 nm CdS buffer, a 40 nm intrinsic ZnO, a 400 nm Al doped ZnO, and Al/Ni top metal contact. Effects of sulfur to selenium (S/Se) compositional ratio on the microstructure, crystallinity, electrical properties, and cell efficiencies have been studied using X-ray diffraction, Raman spectroscopy, field emission scanning electron microscope, I-V measurement system, solar simulator, quantum efficiency measurement system, and time resolved photoluminescence spectrometer. Our fabricated Cu2ZnSn(S,Se)4 thin film solar cell shows the best conversion efficiency of 9.24 % (Voc : 454.6 mV, Jsc : 32.14 mA/cm2, FF : 63.29 %, and active area : 0.433 cm2), which is the highest efficiency among Cu2ZnSn(S,Se)4 thin film solar cells prepared using sputter deposited metallic precursors and without using a toxic H2Se gas. Details about other experimental results will be discussed during the presentation.

• Journal of Microbiology
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• v.39 no.1
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• pp.37-41
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• 2001

The fission yeast Schizosaccharomyces pombe contains two distinct superoxide dismutase (SOD) activities, one in the cytosol encoded by the $sod2^{+}$ gene and the other in mitochondria. The $sod2^{+}$ gene encoding putative mitochondrial manganese superoxide dismutase (MnSOD) was isolated from the S. pombe genomic library using a PCR fragment as the probe. The nucleotide sequence of the $sod2^{+}$ gene and its flanking region (4051 bp HindIII fragment) was determined. An intron of 123 nt in size was predicted and confirmed by sequencing the cDNA following reverse transcription PCR. The predicted Sod2p consists of 218 amino acid residues with a molecular mass of 24,346 Da. The deduced amino acid sequence showed a high degree of homology with other MnSODs, especially in the metal binding residues at the active site and their relative positions. The transcriptional start site was mapped by primer extension at 231 at upstream from the ATG codon. A putative TATA box(TATAAAA) was located 58 nt upstream from the transcriptional start site and putative polyadenylation sites were located at 1000, 1062, and 1074 nt downstream from the ATG start codon.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1756-1760
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• 2004

Circulating Fluidized-Bed (CFB) boilers which have been operated in Korea were manufactured by the design technology of foreign leading companies. As they are not active to transfer their technology, domestic companies don't have the enough ability to design it independently yet. Doosan Heavy Industries & Construction Co. Ltd. and Korean Institute of Energy Research are trying to develop and improve the particle re-circulating device among the components of CFB boiler. Our purpose is to control the amount of particles leaving the re-circulating system by adjusting utility air and reuse the heat of circulating particles. The results of experiments with cold model system show that a fluidization state in the particle re-circulating device is very stable when the amount of utility air is supplied to its wind box with 2.29 times of minimum fluidization velocity. Also the amount of particles entering the riser don't increase linearly when the amount of utility air is supplied over 2.5 times of minimum fluidization velocity. Now we are testing its functional run with the hotstate experiment set-up.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2367-2374
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• 2011

Today's digital broadcasting services based on DVB-SI standard are provided a two-way broadcast. However, using the power of STB if the user does not use a waste of time spent on standby power is becoming a serious problem. Accordingly, for energy savings both at home and abroad to actively promote green policies, but highly functional STB, the internal software to automatically update the appropriate scheduling techniques are not shown, power usage does not meet the standard can. Therefore, In this paper We analyze the current STB technology and the problems, as proper use of power to the standard STB design scheme and the automatic software installation method of operation is presented.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.2
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• pp.1-10
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• 2020

The technology and market size of image sensors continue to develop thanks to the release of image sensors that exceed 100 million pixels in 2019 and expansion of black box camera markets for vehicles in addition to existing mobile applications. We review the technology flow of image sensors that have been constantly evolving for 40 years since Hitachi launched a 200,000-pixel image sensor in 1979. Although CCD has made inroads into image sensor market for a while based on good picture quality, CMOS image sensor (CIS) with active pixels has made inroads into the market as semiconductor technology continues to develop, since the electrons generated by the incident light are converted to the electric signals in the pixel, and the power consumption is low. CIS image sensors with superior characteristics such as high resolution, high sensitivity, low power consumption, low noise and vivid color continue to be released as the new technologies are incorporated. At present, new types of structures such as Backside Illumination and Isolation Cell have been adopted, with better sensitivity and high S/N ratio. In the future, new photoconductive materials are expected to be adopted as a light absorption part in place of the pn junction.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.28-38
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• 2023

Plant viruses are responsible for worldwide production losses of numerous economically important crops. The most common plant RNA viruses are positivesense single-stranded RNA viruses [(+)ss RNA viruses]. These viruses have small genomes that encode a limited number of proteins. The viruses depend on their host's machinery for the replication of their RNA genome, assembly, movement, and attraction to the vectors for dispersal. Recently researchers have reported that chloroplast proteins are crucial for replicating (+)ss plant RNA viruses. Some chloroplast proteins, including translation initiation factor [eIF(iso)4E] and 75 DEAD-box RNA helicase RH8, help viruses fulfill their infection cycle in plants. In contrast, other chloroplast proteins such as PAP2.1, PSaC, and ATPsyn-α play active roles in plant defense against viruses. This is also consistent with the idea that reactive oxygen species, salicylic acid, jasmonic acid, and abscisic acid are produced in chloroplast. However, knowledge of molecular mechanisms and functions underlying these chloroplast host factors during the virus infection is still scarce and remains largely unknown. Our review briefly summarizes the latest knowledge regarding the possible role of chloroplast in plant virus replication, emphasizing chloroplast-related proteins. We have highlighted current advances regarding chloroplast-related proteins' role in replicating plant (+)ss RNA viruses.