• Journal of Power System Engineering
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• v.18 no.3
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• pp.73-78
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• 2014

Recently, Free cooling system usage has increased at many buildings in intermediate and winter season. Free cooling system is used to reduce the energy consumption of refrigeration in that season. Free cooling system is refrigeration system using cooled water. In general, this system is applied with the building having refrigeration load at all time such as a data center. In this study, energy consumption of a data center taking free cooling system in Ulsan was evaluated by the software HYSYS. the main result is as in the following : free cooling system is effective from January to April and from November to December. In case of Ulsna in 2013, using free coolng system is able to spend refrigeration energy of about 15% less than existing system. According to this result, it is appropriated that free cooling system is used in building having refrigeration load at all time such as data center.

• Journal of Applied Biological Chemistry
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• v.50 no.3
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• pp.164-169
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• 2007

Three coniferous essential oils were extracted from Abies koreana, Cryptomeria japonica, and Torreya nucifera by hydrodistillation. The chemical composition of each oil was analyzed by GCMS, and their antimicrobial activities were tested against two bacteria and one yeast strains. Fortyseven compounds were identified from A. koreana oil, 39 from C. japonica, and 59 from T. nucifera. Main components of the essential oils were limonene (23.5%), bornyl acetate (17.9%), ${\alpha}-pinene$ (11.1%), and camphene (10.2%) in A. koreana, kaurene (26.3%), ${\gamma}-eudesmol$ (19.0%), elemol (6.9%), and sabinene (5.1%) in C. japonica, limonene (13.5%), ${\delta}-cadinene$ (10.5%), ${\alpha}-bisabolol$ (10.2%), and ${\alpha}-copaene$ (7.7%) in T. nucifera. Among the three coniferous trees tested, the essential oils of A. koreana exhibited higher and broader antimicrobial activity against the tested organisms than those of C. japonica and T. nucifera.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.311-314
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• 2007

Citrus sunki Hort. ex Tanaka is one of several Jeju-native citrus fruits. A number of biological properties for citrus fruits have been suggested, however little is known about those of C. sunki. The present study tested whether fermented product of C. sunki peel (FSP) might affect the activities of enzymes regulating ethanol metabolism. Effects on body weight gain as well as on fatty liver formation were also investigated. The activities of alcohol dehydrogenase and aldehyde dehydrogenase were stimulated remarkably by FSP. Excessive ethanol-induced cytotoxicity was also prevented by FSP in HepG2 cells. FSP decreased the weight gain and fatty liver formation induced by a high-fat diet in mice. From these results, FSP might be a potent source of neutraceuticals useful for preventing ethanol-induced health problems.

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.212-215
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• 2009

요구되는 접착력과 그라프트율을 만족시킬 수 있는 변성폴리프로필렌의 제조 기술 확립을 목표로 변성폴리프로필렌의 최적 합성을 위한 과산화물, 변성폴리프로필렌의 최적 합성을 위한 촉매 및 반응몰비, 변성폴리프로필렌의 최적 합성을 위한 반응온도, 반응시간 확립을 통한 변성 PP 제조기술을 개발하였으며, $90{\Phi}$ extruder에서 상업 생산을 위한 공정 제어 기술 확립과 접착력과 그라프트율 등을 나타내는 변성폴리프로필렌의 최적 합성 조건 확립을 통한 폴리프로필렌 엘라스토머 복합수지용은 물론 강관 코팅용, 시트 및 필름용 등의 변성 폴리프로필렌 제조기술을 개발하였다. 이들 변성 PP를 활용하여 매트릭스 및 필러, 분산 조건 변경 시험, 엘라스토머 폴리프로필렌 컴파운드 최적 분산 조건 확립, 엘라스토머 폴리프로필렌 컴파운드 pilot 생산 및 제품 분석을 통하여 초고강성 범퍼, 룸미러 케이스 소재, 인패널, 도어용으로 사용될 수 있는 자동차 부품용 폴리프로필렌 복합수지 개발을 완료하였다.

• Journal of the Korea Society of Computer and Information
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• v.13 no.3
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• pp.189-196
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• 2008

In this modern society, a main tendency of crime is to increase in the incidence frequency of cyber crime. Varied criminal techniques from simple crimes to highly specialized crimes appear through cyber space. With the expansion of Internet spread, ordinary people increasingly have an opportunity to have access to information media and their possibilities to be involuntary associated with crimes get higher. In this sense, its seriousness is great. This study examined the present state of cyber crimes that appear through their several types and characteristics and the problems of police response to cyber crimes, and suggest effective response of police officer.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.331-336
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• 2002

Satellite positioning technology has been widely used in all kinds of military and civil land, marine, space and aeronautical target positioning tasks, navigation activities and accurate surveying measurements since 90s in the last century due to it advantage in providing all-weather, real-time, three dimensional and high precision positioning information, as well as speed and accurate timing information. By now, it has already formed a new hi-tech industry basically. This paper briefly reviews the development of the global satellite positioning and navigation technologies including the basic information of China′s "Plough navigation system", introduces the history of satellite positioning technology and its major application fields as well as the status quo of this being industrialized trade in China, gives an account of the writers′ vision for the application and prospect of the satellite positioning technologies in China, and approaches the tactics and stresses of the satellite positioning technology′s application and its industrialization future in China.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.34-39
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• 2014

In this study, the structural analysis and the modal analysis are conducted to investigate the stress level, the deformation characteristics and the natural modes of the casing of a planetary gear reducer for a 800kW grade pulverizer mill. The casing is subjected to the load, 2800 kN, from the lump coals in the pulverizing process. Because of the symmetry, the half portion of the reducer casing is modeled for the stress analysis. But the full model is used to find out the eigenvalues and natural modes for the modal analysis. The contact conditions are applied between the thrust pad bearing and the adjacent contacting parts. The results shows that the casing structure has the sufficient strength and stiffness to support the load under consideration. ANSYS version 15 is employed to perform the numerical study.

• Progress in Superconductivity and Cryogenics
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• v.23 no.4
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• pp.56-60
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• 2021

The microwave Radar used for special purposes in the past is being applied in various areas due to the technological advancement and cost reduction, and is particularly applied to autonomous driving in the automobile field. The FMCW (Frequency Modulated Continuous Wave) Radar can acquire level information of liquid in vessel based on the beat frequency obtained by continuously transmitting and receiving signals by modulating the frequency over time. However, for cryogenic fluids with small impedance differences between liquid medium and gas medium, such as liquid nitrogen and liquid hydrogen, it is difficult to apply a typical Radar-based level meter. In this study, we develop an 80 GHz FMCW Radar for level measurement of cryogenic fluids with small impedance differences between media and analyze its characteristics. Here, because of the low intrinsic impedance difference, most of the transmitted signal passes through the liquid nitrogen interface and is reflected at the bottom of the vessel. To solve this problem, a radar measurement algorithm was designed to detect multiple targets and separate the distance signal to the bottom of the vessel in order to estimate the precise position on the liquid nitrogen interface. Thereafter, performance verification experiments were performed according to the liquid nitrogen level using the developed radar level meter.

• Advances in concrete construction
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• v.7 no.1
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• pp.11-22
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• 2019

A comprehensive assessing approach for durability of reinforced concrete structures dealing with the corrosion process of rebar subjected to the attack of aggressive agent from environment was proposed in this paper. Corrosion of rebar was suggested in the form of combination of global corrosion and pitting. Firstly, for the purposed of considering the influence of rebar's radius, a type of Plane Corrosion Model (PCM) based on uniform corrosion of rebar was introduced. By means of FE simulation approach, global corrosion process of rebar regarding PCM and LCM (Linear Corrosion Model) was regressed and compared according to the data from Laboratoire $Mat{\acute{e}}riaux$ et $Durabilit{\acute{e}}$ des Constructions (LMDC). Secondly, pitting factor model of rebar in general descend law with corrosion degree was introduced in terms of existing experimental data. Finally, with the comprehensive numerical simulation, the durability of an existing arch bridge was studied in depth in deterministic way, including diffusion process and sectional strength of typical cross section of arch, crossbeam and deck slab. Evolution of structural capacity considering life-cycle rehabilitation strategy indicated the degradation law of durability of reinforced arch bridges.

• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.334-345
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• 2018

Spore-forming Bacillus species are commercially available probiotic formulations for application in humans. They have health benefits and help prevent disease in hosts by combating entero-pathogens and ameliorating antibiotic-associated diarrhea. However, the molecular and cellular mechanisms of these benefits remain unclear. Here, we report the draft genome of a potential probiotic strain of Bacillus clausii B106. We mapped and compared the probiotic profile of B106 with other reference genomes. The draft genome analysis of B106 revealed the presence of ADI pathway genes, indicating its ability to tolerate acidic pH and bile salts. Genes encoding fibronectin binding proteins, enolase, as well as a gene cluster involved in the biosynthesis of exopolysaccharides underscored the potential of B106 to adhere to the intestinal epithelium and colonize the human gut. Genes encoding bacteriocins were also detected, indicating the antimicrobial ability of this isolate. The presence of genes encoding vitamins, including Riboflavin, Folate, and Biotin, also indicated the health-promoting ability of B106. Resistance of B106 to multiple antibiotics was evident from the presence of genes encoding resistance to chloramphenicol, ${\beta}$-lactams, Vancomycin, Tetracycline, fluoroquinolones, and aminoglycosides. The findings indicate the significance of B. clausii B106 administration during antibiotic treatment and its potential value as a probiotic strain to replenish the health-promoting and disease-preventing gut flora following antibiotic treatment.