• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.916-917
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• 2006

Solid Oxide Fuel Cell technology uses powder processes to produce electrodes with residual porosity by partially sintering a mixture of electronically and ionically conducting particles. We model porous fuel cell electrodes with 3D packings of monosized spherical particles. These packings are created by numerical sintering. Each particle-particle contact is characteristic for an ionic, electronic or electrochemical resistance. The numerical packing is then discretized into a resistor network which is solved by using Kirchhoff's current law to evaluate the electrode's electrochemical performance. We investigate in particular percolation effects in functionally graded electrodes as compared to other types of electrodes.

• 한국정밀공학회지
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• 제26권9호
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• pp.135-142
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• 2009

In the present study replication of microstructured surfaces by microinjection molding was carried out. For a fabrication of mold inserts, nickel microstructures having various characteristic dimensions were fabricated by nickel electroforming onto Si mother microstructures. In addition, reverse nickel microstructures based on the electroformed nickel microstructures were successfully realized by electroforming with passivation process. The fabricated nickel microstructures were used as mold inserts for a replication of microstructured surfaces by microinjection molding. Microinjection molding experiment was carried out under three different processing conditions, which revealed effects of a packing stage and mold wall temperature. The microinjection-molded microstructured surfaces were characterized by using an atomic force microscope (AFM). It was found that mold wall temperature could enhance replication quality resulting in the precise microstructured surfaces.

• 폴리머
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• 제29권3호
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• pp.308-313
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• 2005

광감응성 azobenzene 그룹이 분자의 주위 환경에 따라 광이성화 반응이 변화하는 것을 in-situ UV/Vis 분광 실험법과 광학 이방성 측정법을 이용하여 조사하였다. 4-Hyhoxyazobenzene을 포함하는 필름에 광조사함과 동시에 trans-isomer와 cis-isomer 특성 피크의 세기 변화를 측정하여 azobenzene 그룹의 가역적이며 반복적인 광이성화 반응을 알수 있었다. Azobenzene 자기조립체 박막이 입혀진 기판을 액정 셀의 배향막으로 사용하여 액정의 배향을 유도하였을 때, trans-azobenzene 그룹들이 조밀한 packing을 하며 기판에 수직으로 배열한 자기조립체 구조 때문에 액정 분자들도 수직 homeotropic 배향을 하였다. 이와 같은 자기조립체 박막의 액정 셀에 UV 빛을 노광하면 azobenzene그룹이 광이 성화 반응을 일으켜 cis-isomer로 변하게 되며, 이로 인해 액정의 배향이 수직에서 수평 planar 배향으로 변함을 알 수있었다.

• 한국식품조리과학회지
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• 제29권2호
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• pp.169-175
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• 2013

The purpose of this study was to provide the basic information necessary to efficiently run a coffee shop. It comparatively analyzes the relative importance and satisfaction of side menu selection characteristics through analyses on customer importance-satisfaction when selecting a side menu as well as their usage behavior of the side menu at coffee shops. According to reason price the analysis result on the differences in the coffee shop side menu importance and satisfaction, there was a difference because the importance of selecting a side menu was higher for the attributes of taste, health, packing & appearance, economics and personnel service compared to satisfaction among which the price of a side menu was found to be the top priority for improvement. The significance of coffee shop side menu for the respondents prior to usage as well as their satisfaction after usage was evaluated in order to comparatively analyze the relative importance and achievement of each characteristic through the IPA. The result indicated that the variables positioned in the Concentrate Here area (II) were related to economic feasibility such as reasonable price, appropriate price of set menu, telecommunication company affiliated service and coupon usage and point accumulation. As for the Keep up the Good Work area (I), there were many variables regarding personnel service including taste of side menu, blending with coffee, clean packing, clean packaging, staff's side menu knowledge, staff's quick response, staff's politeness and staff's sincere response. As for the variables in the Low Priority area (III), health variables on health such as nutritional value, eco-friendly food materials and calories were observed.

• 정보보호학회논문지
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• 제22권2호
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• pp.179-188
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• 2012

악성코드의 탐지 및 분석 회피 기술 중 실행 압축 기술은 악성코드의 용량을 줄이고 분석가가 코드를 분석할 때 혼란을 주도록 코드를 변형하고 있다. 따라서 악성코드의 확산이 용이해지고 분석하는데 시간이 오래 걸려 신속한 대응이 어렵게 만들고 있다. 최근에는 이러한 실행 압축된 악성코드에 대응하기 위하여 실행 압축 해제 관련 연구가 진행되고 있다. 실행 압축 프로그램은 실행되면 실행 압축을 해제하게 된다. 실행 압축 해제 때 압축되어 있던 데이터가 해제 되면서 실행 압축 파일의 데이터가 변경되거나 추가되어 데이터의 변화가 생기게 된다. 이때 이러한 변화 때문에 실행 압축 파일의 엔트로피 값이 변화하게 된다. 실행 압축 해제가 끝나게 되면 이러한 데이터 변화가 끝나고 실제적인 프로그램이 수행되므로 엔트로피 값이 변화하지 않게 된다. 그러므로 이러한 성질을 이용하여 실행 압축 해제되는 시점을 찾게 되면 실행 압축 알고리즘에 상관없이 실행 압축을 해제 할 수 있게 된다. 본 논문에서는 실행 압축 파일의 압축 해제 때의 엔트로피 값 변화량을 보고 실행 압축 해제가 끝나는 시점을 판단하여 실행 압축을 해제하는 방법을 제안한다.

• 대한소아치과학회지
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• 제33권1호
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• pp.139-145
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• 2006

하마종은 구강저에 발생하는 점액 낭종으로 주로 설하선과 관련된다. 즉, 하마종은 설하선 분비도관의 파열로 인하여 타액이 분비도관에서 빠져나와 주위의 연조직 내에 저류됨으로써 발생하는 가성 낭으로 정의되며, 원인은 설하선 도관의 파열이나 폐색이다. 하마종의 임상소견은 청색의 투명한 종창이 구강저의 소대를 중심으로 편측으로 발생하며, 무통성이며, 촉진시 파동성을 나타낸다. 조직소견은 결합 조직 내 와동이 형성되지만, 낭 벽은 상피세포가 아닌 육아조직으로 구성되는 가성 낭을 관찰할 수 있다. 하마종의 첫 번째 치료법으로는 하마종의 내벽이 구강점막의 일부가 되도록 만들어 주는 조대술을 고려할 수 있다. 본 증례는 특징적인 하마종의 임상소견을 보이는 환아에게 gauze-packing등을 동반한 조대술을 이용하여 치료한 증례로써 양호한 치료결과를 보여 보고하고자 한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.904-908
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• 2008

As the various industrial production machinery has come into being by development of industrial technology, the productivity of the basic industrial production machinery has improved and the international competitiveness of the one of Korea has strengthened. However, at the same time, noise from various industrial production machinery disturbs the quiet environment. There are 35 kinds of the noise emission machinery defined in the noise and vibration control act according to the horse power and the number of machinery. These were classified in 1992 through investigation from 1990 to 1991, and the characteristic of the noise emission machinery may be different from the past one. So we need to investigate the characteristics of the noise emitted by machinery to control it rightly. Also we need to investigate the new noise emission machinery which has come into being recently. In this survey, we measured sound intensity of 32 noise emission machinery to calculate the sound power levels of those and investigated the characteristic of the sound power level of those according to the frequency. From the survey, we found that the forging machine, concrete pipe and pile making machine, sawing machine, etc. are the noisy machinery. And the automatic packing machine, sewing machine, centrifuge, etc. are the silent machinery. Also the generator, the concrete pipe and pile making machine, the printing machine, etc. emit the low frequency noise, and the molding machine, the stone cutter, the metal cutter, etc. emit the high frequency noise. Lastly, we intented to propose the proper guide line of classifying noise emission machinery.

• Advances in concrete construction
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• 제1권4호
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• pp.341-358
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• 2013

Due to fast growth in urbanisation, a highly developed infrastructure is essential for economic growth and prosperity. One of the major problems is to preserve, maintain, and retrofit these structures. To meet the requirements of construction industry, the basic information on all the mechanical properties of various concretes is essential. This paper presents the details of development of various concretes, namely, normal strength concrete (around 50 MPa), high strength concrete (around 85 MPa) and ultra high strength concrete (UHSC) (around 120 MPa) including their mechanical properties. The various mechanical properties such as compressive strength, split tensile strength, modulus of elasticity, fracture energy and tensile stress vs crack width have been obtained from the respective test results. It is observed from the studies that a higher value of compressive strength, split tensile strength and fracture energy is achieved in the case of UHSC, which can be attributed to the contribution at different scales viz., at the meso scale due to the fibers and at the micro scale due to the close packing of grains which is on account of good grading of the particles. Micro structure of UHSC mix has been examined for various magnifications to identify the pores if any present in the mix. Brief note on characteristic length and brittleness number has been given.

• 폴리머
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• 제26권4호
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• pp.516-522
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• 2002

4급 암모늄기를 관능기로 갖는 아민화 아크릴계 이온교환섬유를 이용하여 연속식 흡착공정 중 linear alkylbenzene sulfonate(LAS)의 흡착특성을 확인하였다. 아민화 아크릴계 이온교환섬유의 LAS흡착성능은 온도가 증가함에 따라 증가하였으며 $40^{\circ}C$에서 최적 흡착성능을 나타내었다. 또한 컬럼 베드 충진비(L/D)의 변화에 따른 LAS 이온의 흡착능은 L/D>2에서 최대 흡착능을 나타내었다. pH 변화에 따른 LAS이온 흡착능은 pH가 증가함에 따라 증가하는 경향을 나타내었고, pH 7에서 최대 흡착능을 나타내었다. 유속변화에 따른 LAS 흡착능은 유속이 증가할수록 낮아졌으며 농도가 높을수록 떨어졌다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.275-278
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• 2007

In family mold, defects are frequently occurred by an excessive packing the smaller volume cavity during molding. Although runner size could be optimized by CAE analysis or experimental data, the filling imbalance is hardly avoided in the actual injection molding process by various means. Before this study, we developed a variable-runner system for balancing the cavity-filling for three resins (ABS, LDPE, and PA66) in the family-mold, and examined the effect of cross-sectional area reduction of a runner in the system. In this study, we examined the conditions of the pressure and temperature in the system with a CAE analysis. We also analyzed the influence of the rheological characteristic of resins to the balancing-capability of the system in order to help mold designers easily adopt the variable-runner system to their design.