• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.13.2-13.2
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• 2009

전도성 고분자는 재료의 경제적 측면 이외에 반도체로서의 다양한 전기적 특성, 생물학적 적합성, 다양한 합성 가능성 등의 우수한 장점을 지니고있어 많은 분야에 응용되고 있다. 그러나 유기물질이라는 한계로 인하여 기존 nano/microfabrication에서 일반적으로 적용되는 패터닝 방법을 적용하는데 어려움이있다. 따라서 많은 연구자들이 독립적인 나노 크기 개체를 만든 후 이의 자가 조립, 혹은 이와 유사한 방법에 의해 소자를 형성하고자 하는 노력을 기울이고 있다.이러한 bottom-up방식에 의한 소자 구성은 나노크기의 전도성 고분자 물질을 소자화하는데에는 성공하고 있으나, 복잡한 패터닝과 다양한 크기의 나노구조체를 정확한 위치에 정렬시키는 문제에 있어서 명확한 해답을 제시하지 못하는 실정이다. 본 연구에서는 현재 보편적으로 이용되고 있는 금속의nano/microfabrication공정과 전도성 폴리머의 전해합성를 복합화하여 고정밀도 및 다양한 패턴의 나노 소자를 구현하고자하였다. 이를 위하여 전해합성 조건에 따른 polypyrrole의전기적 특성을 평가하였으며, 하부 금속전극관의 복합적층화를 통한 접촉저항의 최소화를 구현하고자 하였다. 또한 이와 같은 self-alignedelectropolymerization방법을 이용하여 구성된 nano/micro 소자의 gas sensor 및 bio sensor로서의 적용가능성에 대하여평가하였다.

• Journal of the Korean Applied Science and Technology
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• v.37 no.5
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• pp.1200-1207
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• 2020

We have fabricated the supercapacitor composed of porous activated carbon, metal-organic framework (MOF) with polymer based solid state electrolyte as a "ion gel" and characterized its electrochemical behaviour as a function of the MOF contents. The electrochemical properties of the supercapacitor were analyzed via cyclic voltammetry(CV), electrochemical impedance spectroscopy(EIS) and galvanostatic charge/discharge test. As a results, the supercapacitor based on porous activated carbon/MOF composite showed the highest capacitance value at 0.5 wt% of MOF contents and decreased capacitance with increase MOF contents over the 0.5 wt%. Consequently, the porous activated carbon/MOF composite based supercapacitor is applicable to various aspect for energy storage device.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1153-1159
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• 2015

Recently, synthetic biopolymers and bioceramics such as poly (${\varepsilon}$-caprolactone)(PCL), hydroxyapatite, tricalcium phosphate, biphasic calcium phosphate(BCP), and zirconia have been used as substrates to generate various tissues or organs in tissue engineering. Thus, the purpose of this study was the characterization of $ZrO_2$/BCP/PCL(ZBP) scaffold for bone tissue regeneration. Based on the result of single-line test, blended 3D ZBP scaffolds with fully interconnected pores and new complex pore pattern of $45^{\circ}+135^{\circ}$-type and staggered-type were successfully fabricated using a polymer deposition system. Furthermore, the effect of ZBP scaffold on mechanical property was analyzed. In addition, in vitro cell interaction of ZBP scaffold on MG63 cells was evaluated using a cell counting kit-8(CCK-8) assay.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.10a
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• pp.192-195
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• 2003

최근 첨단기술 집약형 자동화 시스템과 정보기술의 발달에 따라 산업은 고도화, 정밀화되고 있다. 특히 안전분야 중 기능성 고분자 재료의 응용 분야로서 carbon black, carbon fiber, graphite, 금속 분말 등의 전도성 충전재를 고분자 matrix에 혼입하여 전도성 복합재료를 성형가공하는 기술이 개발되고 있다. 이를 이용한 복합성형체는 과전류 차단, 회로 보호, 전자파 차폐효과 등의 특성을 이용한 electrical hazard 감소 효과, 제어설비, 자동화 설비, 제조설비 등 각종 산업설비의 정밀제어, 과전류차단 및 외란 방지 등에 다양한 용도로 활용되고 있다.(중략)

• Proceedings of the Membrane Society of Korea Conference
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• 1997.10a
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• pp.124-126
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• 1997

1. 서론 : 투과증발이란 비다공성 고분자막을 이용하여 수착, 확산, 및 증발기구를 통해 액체혼합물을 분리하는 기술이다. 따라서 투과증발의 분리효율은 고분자막의 종류 및 형태의 다양성뿐만 아니라 여러 단계의 기구 특성에 의해 결정된다. 일반저긍로 투과증발막의 성능은 분리하고자 하는 물질에 대한 선택도와 투과도로서 나타날 수 있다. (중략) 본 연구에서는 Poly(dimethylsiloxane)과 세라믹 지지체의 복합막을 이용하여 IPA(Isopropanol)/물 계에서의 여러 조업변수에 따른 IPA의 분리특성을 연구하였다.

• Korean Journal of Computational Design and Engineering
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• v.4 no.2
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• pp.121-126
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• 1999

Existing data structures for non-manifold solid modelers use basic dat entities, such as vertex, edge, loop, face, shell, and region to find adjacency relationships. But, no one clearly identified what additional types of data entitles are necessary to represent incidence relationships. In this paper, we classified the boundary information of vertex, edge, face , and region from the 3-D space view. As the results we can clearly define the boundary information required for adjacency relationships. The existing B-rep data structures for solid modeler are compared whether they have the required boundary information.

• Membrane Journal
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• v.26 no.6
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• pp.432-448
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• 2016

In the last decade, various types of energy harvesting and conversion systems based on ion exchange membranes (IEMs) have been developed for eco-friendly power generation and energy-grid systems. In these membrane-based energy systems, high ion selectivity and conductivity properties of IEMs are critical parameters to improve efficiency of the systems such as proton exchange membrane fuel cells, anion exchange membrane fuel cells, redox flow batteries, water electrodialysis for hydrogen production, and reverse electrodialysis. This article suggests variable approaches to overcome trade-off limitation of polymeric membrane ion transport properties by reviewing various types of composite ion-exchange membranes including novel inorganic-organic nanocomposite membrane, surface modified membranes, cross-linked and pore-filled membranes.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.11a
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• pp.166-171
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• 2002

폐자원의 재활용은 현재 미래산업을 발전시키는데 중요한 변수로 작용하고 있으며, 폐플라스틱의 경우 통신 케이블 덕트, 고속전철용 케이블 덕트, 선박용 구조체등 고부가가치 제품으로의 기술개발이 활발히 진행되고 있다. 폐 Polyolefin 계열의 수지는 성형가공이 적절한 MFI(Melt flow index)와 뛰어난 기계적 물성, 가공 성형성 등으로 인해 다양한 형태와 용도로 recycling되고 있으나, 재생시 다수 Grade에 의한 분별, 분리수거의 어려움, 상용성결여, 난연성 부재 그리고 70% 대의 기계적 물성 회복율로 인해 그 용도가 제한되고 있는 실정이다.(중략)

• Composites Research
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• v.23 no.6
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• pp.14-18
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• 2010

Among the factors that threaten spacecraft, Micrometeoroid and Orbital Space Debris(MMOD) cause damage to spacecraft and impact velocity is about 8~70km/s. Nowadays, various Whipple Shield are studied and applied to protect spacecraft. As the materials used to Shielding System, aluminum is usually used but composite is also used increasingly. So this study compared characteristics of hypervelocity impact of Aluminum and composites through finite element analysis. The Projectile was a spherical shape using Aluminum 2017-T4, and aluminum plate was using Aluminum 6061-T6, CFRP plate was using T300/5208. Initial impact velocity of projectile was 1km/s. As a result, kinematic energy of projectile decreased to about 64J and about 63J for aluminum plate and CFRP plate, respectively after impact. Although both results is almost same about the absorption of impact energy, you can think the CFRP has good ballistic characteristic, because CFRP is lighter about 1.7 times compared with density of aluminum.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.14-22
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• 2001

Off-line handwritten numeral recognition is a very difficult task and hard to achieve high recognition results using a single feature and a single classifier, since handwritten numerals contain many pattern variations which mostly depend upon individual writing styles. In this paper, we propose handwritten numeral recognition system using hybrid features and combined classifier. To improve recognition rate, we select mutually helpful features -directional features, crossing point feature and mesh features- and make throe new hybrid feature sets by using these features. These hybrid feature sets hold the local and global characteristics of input numeral images. And we implement combined classifier by combining three neural network classifiers to achieve high recognition rate, where fuzzy integral is used for multiple network fusion. In order to verify the performance of the proposed recognition system, experiments with the unconstrained handwritten numeral database of Concordia University, Canada were performed. As a result, our method has produced 97.85% of the recognition rate.