• 한국기계가공학회지
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• 제3권3호
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• pp.24-31
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• 2004

A successful on-line monitoring system for conventional machining operations has the potential to reduce cost, guarantee consistency of product quality, improve productivity and provide a safer environment for the operator. In fine-shape machining, typical signs of tool problems such as vibration, noise, chip flow characteristics and visual signs are almost unnoticeable without the use of special equipment. These characteristics increase the importance of automatic monitoring in fine-shape machining, however, sensing and interpretation of signals ar more complex. In addition, the shafts of the mini-tools break before the typical extensive cutting edge of the tool gets damaged. In this study, the existence of a relationship between the characteristics of the cutting force and tool usage was investigated, and tool breakage detection algorithm by LabVIEW was developed and the following results are obtained. It was possible to use a relative error compare which mainly used in established experiment and investigated tool breakage detection algorithm in time domain which can detect AE and cutting force signals more effective and accurate.

• 대한기계학회논문집B
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• 제33권5호
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• pp.381-388
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• 2009

In some portions of nuclear piping systems, stratification phenomena may occur due to the density difference between hot and cold stream. When the temperature difference is large, the stratified flow under diverse operating conditions can produce high thermal stress, which leads to unanticipated piping integrity issues. The objectives of this research are to examine controvertible numerical factors such as model size, grid resolution, turbulent parameters, governing equation, inflow direction and pipe wall. Parametric three-dimensional computational fluid dynamics analyses were carried out to quantify effects of these parameters on the accuracy of temperature profiles in a typical nuclear piping with complex geometries. Then, as a key finding, it was recommended to use optimized mesh of real piping with the conjugated heat transfer condition for accurate thermal stratification analyses.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.1725-1727
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• 2016

Breast cancer contributes to approximately 23% of the cancer cases identified and 14% of cancer related deaths worldwide. Including a strong association between genetic and environmental factors, breast cancer is a complex and multi factorial disorder. Two high penetration breast cancer susceptibility genes (BRCA1 and BRCA2) have been identified, and germ line mutations in these are thought to account for between 5% and 10% of all breast cancer cases. The human BRCA1 gene, located on 17q, is involved in the regulation of cell proliferation by aiding in DNA repair, transcriptional responses to DNA damage and cell cycle check points. Mutations in this gene enhance cell proliferation and facilitate formation of tumors. Two mutations, the 185 deletion of AG and the 4627 substitution from C to A, are founder mutations in the BRCA1 gene for breast cancer in Asian populations. Allele specific PCR was performed to detect these selected mutations in 120 samples. No mutation of 4627 C to A was detected in the samples and only one of the patients had the 185 del AG mutation in the heterozygous condition. Our collected samples had lower consanguinity and family history indicating the greater involvement of environmental as compared to genetic factors.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.192-196
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• 2005

Abstract Oligotrophic microbial fuel cells (MFCs) were tested for the continuous monitoring of low biochemical oxygen demand (BOD) by using artificial wastewater, containing glucose and glutamate, as check solution. Ten times diluted trace mineral solution was used to minimize the background current level, which is generated from the oxidation of nitrilotriacetate used as a chelating agent. The feeding rate of 0.53 ml/min could increase the sensitivity from 0.16 to 0.43 ${\mu}$A/(mg BOD/l) at 0.15 ml/min. The dynamic linear range of the calibration curve was between 2.0 and 10.0 mg BOD/l, and the response time to the change of 2 mg BOD/l was about 60 min. The current signal from an oligotroph-type MFCs increased with the increase in salts concentration, and the salt effect could be eliminated by 50 mM phosphate buffer.

• 복식
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• 제52권7호
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• pp.1-11
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• 2002

The shape of floral Pattern in the Period of Baroque could be divided single. bunch and vine. The style of representation was stylized, abstract and realistic. the most of style was stylized. The type of composition was fullness, independent and scattered. Floral patterns were shaped simple and complex and components of design could be classified into flower and leaf. flower and fruit. flower and band. bunch of flower, flower and geometry. flower and pot, flower and animal. flower and crest. Kinds of flower were tulip. common marigold, lily, carnation, small bel]flower. lotus, acandus leaf, pomegranate, strawberry. pine cone and abstract anonymous flower which were unfolded by repeat. Characters of floral Pattern were classical elegance, taste of royalty and lively and damask, velvet, brocade which made with gold and silver so, those were a very brilliant and gorgeous. Characters of design were illustrated plane style and stylization where developed arranged on front by repeat or repeat symmetric of vertical. Art, costumes and textiles in this era were a very rich and colorful. The result of study on Baroque's floral pattern will be used to develope a various textile design and chance to be adopted classical pattern into aesthetic value in our time.

• Journal of Advanced Marine Engineering and Technology
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• 제11권1호
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• pp.72-79
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• 1987

When the wall temperature is very high, a stable vapor film covers the heat transfer surface. The vapor film creates a strong thermal resistance when heat is transferred to the liquid though it. This phenomenon, called "film boiling" is very important in the heat treatment of metals, the design of cryogenic heat exchangers, and the emergency cooling of nuclear reactors. In the practical engineering problems of the transient cooling process of a high temperature wall, the wall temperature history, the variation of the heat transfer coefficients, and the wall superheat at the rewetting points, are the main areas of concern. These three areas are influenced in a complex fashion such factors as the initial wall temperature, the physical properties of both the wall and the coolant, the fluid temperature, and the flow state. Therefore many kinds of specialized experiments are necessary in the creation of precise thermal design. The object of this study is to investigate the heat transfer characteristics in the transient cooling process of a high temperature wall. The slow transient cooling experiment was carried out with a copper block of high thermal capacity. The block was 240 mm high and 79 mm O.D.. The coolant flowed throuogh the center of a 10 mm diameter channel in the copper block. In the copper block, three sheathed thermocouples were placed in a line perpendicular to the flow. These thermocouples were used to take measurements of the temperature histories of the copper block.

• 한국기계가공학회지
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• 제18권12호
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• pp.59-66
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• 2019

In this study, we developed a novel laser sintering deposition system (LSDS) based on solid free-form fabrication (SFF) technology as it has the potential to fabricate complex geometries with controllable architecture for bone tissue engineering applications. The 3D biphasic calcium phosphate (BCP) scaffolds were fabricated with a pore size of 800㎛, a line width and height of 1000㎛, and an overall size of 8.2×8.2×8.0 mm3 according to the design of experiment (DOE) results. Additionally, an optimized manufacturing process using response surface analysis was established to fabricate 3D BCP scaffolds. The fabricated 3D BCP scaffolds were sintered at 950℃, 1050℃, 1150℃, and 1250℃ according to sintering processes with a furnace. As the sintering temperature increased, the porosity increased. Through the compressive strength test, the 3D BCP scaffolds sintered at 1050℃ presented good results of about 0.76 MPa. These results suggest that fabrication methods for 3D bioceramic scaffolds using LSDS may meet the basic requirements for bone tissue engineering.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 추계학술대회 논문집
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• pp.238-243
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• 2003

The solar cells should be operated at the maximum power point because its output characteristics are greatly fluctuated on the variation of insolation, temperature and load. The output power of solar cell is DC, therefore it is necessary to install an inverter among electric power converts. The inverter have to supply a sinusoidal current and voltage to the load and the interactive utility line. In the paper, the proposes a photovoltaic system designed with a step up chopper and single phase PWM voltage source inverter. Synchronous signal and control signal was processed by microprocessor for stable modulation. The step up chopper operates in continuous mode by adjusting the duty ratio so that the photovoltaic system tracks the maximum power point of solar cell without any influence on the variation of insolation and temperature because solar cell has typical dropping character. The single phase PWM voltage source inverter consists of complex type of electric power converter to compensate for the defect, that is, solar cell cannot be developed continuously by connecting with the source of electric power, from 10 to $20\%$. The single phase PWM voltage source inverter operates in situation that its output voltage is in same phase with the utility voltage. The inverter supplies an ac power with high factor and low level of harmonics to the load and the utility power system.

• KIEAE Journal
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• 제11권6호
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• pp.19-28
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• 2011

This study examines the current status on the supply of community facilities based on the supply criteria of present welfare facilities. Analyzing satisfaction of residents about community facilities based on physical supply criteria. The study sets up the concept and proposed trend of the related studies and distinction through the examination of previous researches. Next, the present systematical supply criteria, was used to make indication in order to propose the promotion of improvement on supply criteria for community facilities. Multi dimensional analyzing system and the satisfaction level of the community facility was used to analyze the relationship between the two. The direction of policy improvement according to the analysis is as per the following. First, it is necessary to improve supply criteria of household to guarantee the minimal amount of space. Second, specification of the minimum distance of community facility to residential area in the complex is needed. Also, the presentation of bottom boundary line of the formation area size to expand the size up to minimal level of size is needed. Third, resident exercise facility supply criteria among the community facility supply criteria need to be improved from the number of household base to the size for each household base. Forth, resident resting facility criteria among the community facility supply criteria should be changed from the present criteria of one facility per five hundred households.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제13권1호
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• pp.46-58
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• 2007

최근 많은 소프트웨어 개발 프로젝트들은 지속적으로 요구사항들이 변경되는 대규모의 복잡한 시스템이며 컴포넌트 기반이나 제품계열 소프트웨어 개발 방식과 같이 아키텍처 기반으로 소프트웨어를 개발하고 있다. 이러한 소프트웨어 개발환경에서 생산성이나 유지보수 향상을 위해서는 무엇보다도 유연하고 확장 가능한 아키텍처가 필요하다. 본 논문에서는 CBD(Component Base Development) 기반의 비즈니스 어플리케이션 개발 및 유지보수 시 생산성과 유지보수 향상을 위해 필요한 유연성과 확장성 품질속성을 가진 소프트웨어 아키텍처를 제시하고 이들 품질속성을 달성하기 위한 방법들을 아키텍처 모델을 통해 설명한다. 또한, 본 논문에서는 최근 프리젠테이션(Presentation) 프레임워크(Framework)로 잘 알려진 Struts와 JBean이라 불리는 본 논문에서 제안한 프레임워크의 성능을 비교했다. JBean 프레임워크는 프리젠테이션 프레임워크와 비즈니스 로직 프레임워크를 가지고 있기 때문에 공정한 실험을 위해 JBean에서 비즈니스 로직 프레임워크에 관련된 모듈을 제거하고 단지 프리젠테이션단 프레임워크만 가지고 실험을 한 결과 JBean의 프리젠테이션 단 프레임워크가 평균 초당 18개의 거래를 더 처리하고 있다.