• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1646-1652
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• 2010

The communication in wireless sensor network is divided into several layers, because of each of them do their role, the wireless communication is possible, the MAC (Medium Access Control) layer of the one of sensor network communications layer is used to the data errors, control flow, and manage resources. Using MAC Protocol, it ensures the communication between sensor node. In this paper, highlighted the energy efficiency of the S-MAC, T-MAC protocol it emphasized the efficiency of energy by lessening the woken time of all nods effectively, transmitting and receiving the control packet on only necessary nods through use of a method that RTS packet is added to SYNC packet and making other nods sleep. On sending SYNC+RTS packet and receiving the packet, nod noticed that it wasn't necessary to be awaked on this period, would be in Sleep mode, demonstrated mathematically that energy is more effective than existing protocol, and simulated with MATLAB.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.255-264
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• 2009

Soils containing vanishing materials lead changes in the microstructure of particulate media due to water inflow. Thus, dissolution renders some local unstability. As the moisture contents decease, the component of the vanished materials may affects on the cementation of paniculate materials. This cementation phenomenon has a huge influence on the stiffness, strength and stability under lower stress level. The goal of this study is to introduce the cementation effects on a compressional wave velocity, a shear wave velocity, and the resonant frequency of shear waves. The glass bead and salt water with different mole contents are used. Test results show that the changes of shear and compressional wave velocities consist of three stages. In the first region, compressional wave velocities increase and shear wave velocities decrease with a decreases in reducing water contents from 100% to 90~95%. In the second region, shear and compressional wave velocities become stable at 90~95% to 10% of the water contents. In the third region, shear and compressional wave velocities increases dramatically with a decrease in the water content due to the capillary force and cementation of salt. Furthermore, the resonant frequency of the shear waves shows similar phenomenon. Specimens prepared by glass beads and salt water are proved to be able to provide a meaningful insight in under structural behaviors of the cementation.

• KSBB Journal
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• v.14 no.4
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• pp.434-439
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• 1999

A wild yeast S-13 which has excellent killer toxin activity to gas-producing yeast of traditional Doenjang and Kochujang was selected among forty seven strains of Meju yeasts and identified as Hansenular capsulata S-13 by investigation of the morphological, cultural and physiological properties. The optimal conditions for the production of killer toxin were investigated. H. capsulata s-13 showed the higest killer toxin activities when it was cultured up to the late-log phase of 36 hr in YEPD medium (pH4.5) at $25^{\circ}C$ H. capsultara S-13 showed killer toxin activities to seven strains of industrial yeasts such as S. cerevisiae, C. veratilis and P. membranaefacieus.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.13-18
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• 2007

Eruption disturbance is an abnormal state of eruption that occurs over a broad chronologic age range. There are many factors that influence eruption such as premature loss of primary teeth, supernumerary tooth, local disease, tongue, lip, mastication muscle and trauma. The purpose of this study was to determine the prevalence, patterns and tooth position that have eruption disturbance in children in Seoul, Korea. The subjects were 8,010 new patients who visited the department of Pediatric dentistry of Seoul National University Dental Hospital in 2004-2005. Clinical and radiographic records of the patients were reviewed by the primary investigator who is a pediatric dentist. Notable eruption disturbances included delayed eruption, early eruption and ectopic eruption and the prevalence of eruption disturbance was 8.79%.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.2 s.57
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• pp.123-127
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• 2006

In this study, we evaluated the crow's fret of 95 Korean female by using mechanical assessments; Skin-Visiometer SV 600 and Dermascan C. Transparency profilometry (Skin Visiometer) were using a very thin skin print which allowed parallel light to pass through and was analysed immediately after production. High-frequency (20 MHz) ultrasonography (Dermascan C) enabled non-invasive evaluation in skin thickness and echodensity. We found a correlation between skin roughness and dermal density. Particularly, we showed a significant correlation between skin roughness (R2) and dermal thickness. Also, we demostrated a significant negative correlation between dermal density and dermal thickness (p < 0.05). Therefore, the ultrasonography system might be considered a very useful method in wrinkle evaluation with the transparency profilometry. Further study will be required.

• The Korean Journal of Mycology
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• v.39 no.3
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• pp.194-197
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• 2011

Forty eight strains of yeast were cultured in potato dextorse(PD) broth at $30^{\circ}C$ for 24 hr and centrifuged with 12,000 rpm for 20 min. After concentrated the cultures, antihypertensive angiotensin I-converting enzyme(ACE) inhibitory activities of its concentrates were investigated. Among them, the concentrates from Saccharomyces cerevisiae Y183-3 showed the highest ACE inhibitory activity of 71.8%. The ACE inhibitor from Saccharomyces cerevisiae Y183-3 was maximally produced when Saccharomyces cerevisiae Y183-3 cultured in PD broth at $30^{\circ}C$ for 36 hr.

• Elastomers and Composites
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• v.44 no.2
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• pp.122-133
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• 2009

Rubbers, such as natural rubber, polybutadiene, styrene-butadiene rubber, nitrile-butadiene rubber, chlorinated rubber and EPDM, have been continuously improved in response to a heavy demand and a new property requirement from industry. One of the best ways to realize the improvement is the modification of rubbers through chemical reactions, which produce materials with novel properties. In this review, chemical modification reactions of rubbers that contain carbon-carbon double bond units either in their main backbone or as a side group were briefly summarized. The chemical reactions introduce functional groups or functional polymer chains to polymer backbone, which transform a classical rubber to a highly functional material. Especially, we focused on a controlled/"living" radical polymerization techniques, with which a revolutionary broadening of the spectrum of the materials with well defined molecular weight, molecular weight distribution, chain end-functionality and architectures become possible.

• Microbiology and Biotechnology Letters
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• v.14 no.4
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• pp.305-310
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• 1986

To improve the starch fermentation ability of yeast, hybrids were introduced by protoplast fusion of S. cerevisiae and S. diastaticus. The protoplasts of parental auxotrophic cells were fused in the presence of 10 mM CaCl$_2$and 30% of polyethyleneglycol (M.W 4, 000). The frequencies of fusant formation varied depending upon the strains used and were 3.51$\times$10$^{-4}$ to 5.04$\times$10$^{-4}$ for the regenerated protoplasts. The strains capable of extensive starch hydrolysis produce only 10% to total fusants. The 4 strains were finally selected by the results of starch fermentation and genetic stability test. The DNA content and cell volume of the fusants were greater than those of the parental strains.

• Annual Conference on Human and Language Technology
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• 2004.10d
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• pp.53-61
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• 2004

일반적으로 중국어의 명사구는 기본명사구(base noun phrase), 최장명사구(maximal noun phrase) 등으로 분류된다. 최장명사구에 대한 정확한 식별은 문장의 전체적인 구조를 파악하고 정확한 구문 트리(parse tree)를 찾아내는데 중요한 역할을 한다. 본 논문은 두 단계 학습모델을 이용하여 최장명사구 자동식별을 진행한다. 먼저 기본명사구, 기본동사구, 기본형용사구, 기본부사구, 기본수량사구, 기본단문구, 기본전치사구, 기본방향사구 등 8가지 기본구를 식별한다. 다음 기본구의 중심어(head)를 추출해 내고 이 정보를 이용하여 최장명사구의 식별을 진행한다. 본 논문에서 제안하는 방법은 기존의 단어레벨의 접근방법과는 달리구레벨에서 학습을 진행하기 때문에 주변문맥의 정보를 많이 고려해야 하는 최장명사구 식별에 있어서 아주 효과적인 접근방법이다. 후처리 작업을 하지 않고 기본구의 식별에서 25개 기본구 태그의 평균 F-measure가 96%, 평균길이가 7인 최장명사구의 식별에서 4개 태그의 평균 F-measure가 92.5%로 좋은 성능을 보여주었다.

• Composites Research
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• v.28 no.4
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• pp.226-231
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• 2015

Various characteristics(thermal expansion, microstructure, etc.) and mechanical properties of CNT-aluminum nano composites manufactured by volume production system were evaluated. Also, formability and durability were evaluated for potential applications in automotive parts, via compared with high-elasticity material (A390) and the current commercial product. As a result, this composite has excellent mechanical properties and formability, therefore, to verity its potential for application as light and high strength materials in automobile part.