• 대한임베디드공학회논문지
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• 제12권3호
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• pp.185-192
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• 2017

Due to the characteristics of low power, high durability and high density, NAND flash memory is being heavily used in various type of devices such as USB, SD card, smart phone and SSD. On the other hand, because of another characteristic of flash cell with the limited number of program/erase cycles, NAND flash memory has a short lifetime compared to other storage devices. To overcome the lifetime problem, many researches related to the wear leveling have been conducted. This paper presents a method called a TCB (Tracking Cold Blocks) using more reinforced constraint conditions when classifying cold blocks than previous works. TCB presented in this paper keeps a MCT (Migrated Cold block Table) to manage the enhanced classification process of cold blocks, with which unnecessary migrations of pages can be reduced much more. Through the experiments, we show that TCB reduces the overhead of wear leveling by about 30% and increases the lifetime up to about 60% compared to BET and BST.

• BMB Reports
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• 제51권2호
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• pp.59-64
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• 2018

The airway epithelium is the first place, where a defense mechanism is initiated against environmental stimuli. Mucociliary transport (MCT), which is the defense mechanism of the airway and the role of airway epithelium as mechanical barriers are essential in innate immunity. To maintain normal physiologic function, normal oxygenation is critical for the production of energy for optimal cellular functions. Several pathologic conditions are associated with a decrease in oxygen tension in airway epithelium and chronic sinusitis is one of the airway diseases, which is associated with the hypoxic condition, a potent inflammatory stimulant. We have observed the overexpression of the hypoxia-inducible factor 1 (HIF-1), an essential factor for oxygen homeostasis, in the epithelium of sinus mucosa in sinusitis patients. In a series of previous reports, we have found hypoxia-induced mucus hyperproduction, especially by MUC5AC hyperproduction, disruption of epithelial barrier function by the production of VEGF, and down-regulation of junctional proteins such as ZO-1 and E-cadherin. Furthermore, hypoxia-induced inflammation by HMGB1 translocation into the cytoplasm results in the release of IL-8 through a ROS-dependent mechanism in upper airway epithelium. In this mini-review, we briefly introduce and summarize current progress in the pathogenesis of sinusitis related to hypoxia. The investigation of hypoxia-related pathophysiology in airway epithelium will suggest new insights on airway inflammatory diseases, such as rhinosinusitis for clinical application and drug development.

• 음성과학
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• 제15권2호
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• pp.55-65
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• 2008

Recently, the multi-model based speech recognizer has been used quite successfully for noisy speech recognition. For the selection of the reference HMM (hidden Markov model) which best matches the noise type and SNR (signal to noise ratio) of the input testing speech, the estimation of the SNR value using the VAD (voice activity detection) algorithm and the classification of the noise type based on the GMM (Gaussian mixture model) have been done separately in the multi-model framework. As the SNR estimation process is vulnerable to errors, we propose an efficient method which can classify simultaneously the SNR values and noise types. The KL (Kullback-Leibler) distance between the single Gaussian distributions for the noise signal during the training and testing is utilized for the classification. The recognition experiments have been done on the Aurora 2 database showing the usefulness of the model compensation method in the multi-model based speech recognizer. We could also see that further performance improvement was achievable by combining the probability density function of the MCT (multi-condition training) with that of the reference HMM compensated by the D-JA (data-driven Jacobian adaptation) in the multi-model based speech recognizer.

• 한국정밀공학회지
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• 제32권2호
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• pp.179-184
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• 2015

In the recent field of Machining, with the improving efficiency of processing, the index table is a key unit according to the increase of parts in available processing when working with the three axes at the same time. As an essential product of MCT, the index tables effect an influence on product quality of machined parts. Therefore, it is necessary to design the shape of index table with stability, high stiffness, lightweight structure. In this study, the optimal shape of index table was proposed using by design of experiment. The maximum displacement and stress analysis were carried out by using FEM software. The optimized shape was verified by using the statistical software. The results of shape optimization were confirmed that both displacement and stress were reduced in comparison with initial model.

• 한국게임학회 논문지
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• 제17권3호
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• pp.63-70
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• 2017

인공지능 연구에서 바둑은 위치평가의 어려움과 엄청난 분기수로 인해 가장 도전적인 보드게임으로 여겨지고 있다. 몬테카를로 트리탐색은 이러한 문제점을 극복할 수 있는 고무적인 돌파구이다. 알파고의 숨겨진 아이디어는 주어진 위치에서의 승률을 예상하여 깊은 탐색을 유도한 후 가장 고무적인 착수를 찾아내는 것이었다. 본 논문에서는 무전략 MCTS를 활용하여 9줄바둑에서 프로기사들이 최상의 첫수로 여기는 천원점이 옳다는 것을 확인했으며, 또한 가장 유행하는 첫 수들의 평균승률을 비교했다.

• 반도체디스플레이기술학회지
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• 제18권3호
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• pp.133-139
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• 2019

The utilizations of ceramics in the modern industries are increasing due to the desirable combinations of electrical, mechanical and physical properties found in ceramics. Ceramic materials are brittle, hard, strong in compression, weak in shearing and tension which is prone to affect the defects such as scratch, crack and breakage during the machining. Generally, the defects of the ceramic machining are generated from the structural vibrations of the machine. In this study, the dynamic characteristics of a machining center for ceramic machining were investigated to analyze the structural vibrations for the improved stability. Frequency response test and computer simulation have been conducted for the analysis and the design improvement. The improved design is suggested to suppress vibrations for the higher stability of the machine and further to reduce vibrations. And the result shows that simple design alterations without any change of major parts of the machine can reduce the vibration of the machine effectively.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2003년도 춘계 학술발표대회
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• pp.103-103
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• 2003

This study was carried out to investigate of the biologically active components in germinating Mung bean(Phaseolus radiata L.) and Buckwheat (Fagopyrum esculentum Moench) seeds. During the initial germination, germination ratio of 24 hours pre-soaking Mung bean and Buckwheat seeds were higher about 2∼3% than that of non-soaking. This experiment also was peformed to observe cytotoxic effect of the germinating seeds(germination length : 2, 5, 10mm) extracts against cancer cell lines including human lung carcinoma(Calu-6), human breast adenocarcinoma(MCT-7), human great intestine carcinoma(Caco-2) and human leukemia carcinoma(AML-2/WT). The growth of the cancer cells in medium containing Mung bean and Buckwheat extracts were significantly inhibited degree in proportion to the length of germination seeds, Especially, the results show that a significant shrinkage of Calu-6 cells was observed when the cells were exposed into extract of 10mm germination seeds in germinating Mung bean and Buckwheat seeds.

• 한국게임학회 논문지
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• 제18권5호
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• pp.77-82
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• 2018

바둑은 최상의 착점을 찾기 위해 컴퓨터가 완전탐색을 하여 모든 가능한 착점들을 탐색할 수 없는 가장 복잡한 보드게임이다. AlphaGo 이전에 모든 강력한 컴퓨터바둑 프로그램들은 게임트리 내 매우 큰 분기수와 국면평가에서의 어려움을 극복하기 위해 몬테카를로 트리탐색(Monte-Carlo Tree Search)을 사용해 왔다. 본 논문에서는 MCTS를 활용하여 초소형 바둑에서의 최상의 수순과 덤의 크기를 알고자 했다. 2줄바둑에서의 게임결과는 빅이 되었으며 덤의 크기는 0집, 반면에 3줄바둑에서는 흑이 항상 승리하고 덤의 크기는 9집이 되어야 함을 알아냈다.

• 한국염색가공학회지
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• 제16권5호
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• pp.1-7
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• 2004

Because acid dyes and reactive dyes require acidic condition for adsorption and alkaline condition for fixation respectively, it is difficult to dye nylon/cotton blends in one-bath one-step dyeing method. In this paper we tried to find out the suitable dye and dyeing condition for one-bath one-step dyeing of nylon/cotton blends. MNT type reactive dyes showed higher exhaustion on cotton as compared with MCT type dyes at neutral pH, which means that the MNT type reactive dyes are preferable for one-bath one-step dyeing method. The optimum condition for one-bath one-step dyeing of nylon/cotton blends was found to be pH 7. Wash fastness of fabrics dyed with half-milling type acid dyes was superior to that of fabrics dyed with levelling type acid dyes, when MNT type reactive dyes were used together.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.597-598
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• 2003

I. Objectives Endodontic success depends on thoroughly cleaned and completely obturated root canal system. Effective cleaning and obturation will be achieved by well shaped canal. Numerous methodologies evaluating the efficacy and safety of canal preparation has been developed and the use of micro-computed tomography(MCT) in endodontic research is one of the latest innovations. This scientific tools could overcome the inherent limitations of other methodologies, and possesses the ability to visualize morphological characteristics in a detailed and accurate manner without destruction of the tooth and offers reproducible data in all three dimensions. The purpose of this study was to determine the optimal master apical file size with less transportation and more efficiency in removing the infected dentin. For this purpose we evaluated the transportation of canal center and change of untouched area after preparation sequentially from ＃25 file through ＃40 file with 3 different instruments：Stainless steel(SS) K-type hand instruments(MANI, Japan), ProFile.04 instruments (Dentply Tulsa Dental, USA) and Lightspeed instruments(Lightspeed Technology, San Antonio, USA) using micro-computed tomography.(omitted)