• Journal of the Korean Graphic Arts Communication Society
• /
• v.19 no.1
• /
• pp.75-85
• /
• 2001

This study confirmed different results according to the molecular weight and pore properties of treated pulp. In this study the pre-treated enzyme material was increasing the beating speed compared with non-treated one. And it was observed that the change of freeness according to the combination ratio depended upon the pores size of pulp and that fibers became flexible owing to the physical deformation of fibers themselves through pre-treated enzyme increasing the flexibility of fibers to increase the contact area of fiber and thus resulting in the increase of specific surface area, the increase of fiber bonding strength and the increase of beating speed.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2011.04a
• /
• pp.290-291
• /
• 2011

본 논문에서는 열-전기-기계 하중 하의 지능형 복합재료 보 모델을 전산점근해석기법에 기초하여 개발하였다. 열-전기-기계 하중 하의 구조물은 지난 십년간 많은 연구가 있어왔으나, 주로 고전적 보 모델에 기반을 두어 진행되어져 왔다. 멀티피직스 환경하의 구조물은 여러 가지 하중의 조합과 이에 따른 연성효과의 고려가 필수적이다. 따라서 공학적인 가정이 없는 점근해석기법은 보다 정확한 등가 보 모델을 개발하는데 있어 기반요소가 될 수 있다. 본 연구에서는 3차원 멀티피직스 구성방정식으로부터 출발하여 점근기법을 적용 체계적으로 등가 보 모델을 유도하고 그 해석 결과를 고찰하고자 한다.

• The Journal of Korean Academy of Prosthodontics
• /
• v.38 no.4
• /
• pp.421-426
• /
• 2000

조직공학은 결손된 조직의 구조 및 기능을 신속히 수복할 수 있도록 적절한 생체소재, 세포, 활성인자 세가지 구성요소를 적절히 조합하는 것이다. 이렇게 하므로써 결손된 조직을 대체할 수 있는 세포에 대한 부착, 이동, 증식, 분화조건을 최적상태로 만들어 주는 것이다. 이러한 관점에서 치아임플랜트의 조직 공학적 적용은 다음 몇가지 관점을 고려할 수 있다. 첫째, 인공치아 임플랜트도 넓은 의미에서 그 자체로서 조직공학의 범주에 들어간다고 할 수 있다. 따라서 결손된 치아의 구조 및 기능을 신속히 회복시킬 수 있도록 조직공학적인 관점에서 검토할 수 있다. 생체소재는 표면에너지의 관점에서, 세포는 골모세표와 섬유모세포관점에서, 활성인자는 세포분화 촉진인자의 관점을 고려할 수 있다. 둘째, 치아임플랜트의 기능회복 촉진을 위한 조직공학기법을 부가적으로 적용하는 것이다. 임플랜트와 생체조직사이에 기능성 조직을 신속히 형성시키므로써 임플랜트의 기능회복을 촉진하는 적절한 생체소재, 세포, 활성인자를 적절히 이용하는 정통 조직공학기법을 적용하는 것이다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.11a
• /
• pp.152-154
• /
• 2010

본 연구에서는 내용 기반의 텍스타일 이미지 검색 시스템을 구축하였다. 텍스타일 이미지에 대한 색상, 질감, 모양 특성 추출 조합을 각각 혹은 가중치를 이용한 방법으로 검색한다. 검색은 사용자 인터페이스에서 오라클 데이터베이스 시스템에서 제공되는 이미지의 색상, 질감 특성 값에 대한 검색과 결과 피드백을 보면서 진행된다. 또 검색 대상 이미지들을 유사도에 따라 다차원 비례법에 의하여 2차원 화면에 클러스터링하여 전체 이미지의 군집화 특성을 쉽게 파악할 수 있는 기능을 구현하였다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.9
• /
• pp.559-568
• /
• 2020

Epidermal growth factor (EGF) is a hormone protein that affects cell growth and proliferation, and has various medical applications. In the present study, the gene of human EGF was codon-optimized with E. coli and the expression vector was constructed by cloning into pRSET. In order to obtain the recombinant human EGF in an active form rather than an inclusion body, chaperone co-expression was attempted along with codon optimization, for the first time. The expressed human EGF was isolated in the pure form by performing Ion Exchange Chromatography in two consecutive runs. ELISA analysis showed that the activity of purified EGF was greater than 99%, which is similar to commercially available EGF. Cell proliferation test confirmed that the recombinant human EGF has the ability to promote cell proliferation of human skin fibroblasts. The human EGF expression system of this study gives a significant amount of protein, and does not require the renaturation step and the additional chromatographic system to remove a fusion contaminant, thereby providing a very useful alternative to conventional expression systems for the preparation of recombinant human EGF.

• Korean Journal of Food Science and Technology
• /
• v.28 no.1
• /
• pp.169-178
• /
• 1996

Target parameters such as water solubility index (WSI), intrinsic viscosity (IV), water holding capacity (WHC), oil holding capacity (OHC), soluble dietary fiber (SDF) and microstructure were investigated on three different screw configurations during twin-screw extrusion of wheat bran. WSI of raw wheat bran (RWB) was 13.7%, while that of extrudates ranged $16.3{\sim}23.2%$ when extruded using screw configurations with 5 reverse screw elements (RSE). It was found that the moisture content of RWB greatly affected WSI of extrudates. IV of wheat bran extrudates increased from 10.6 ml/g of RWB to $37.86{\sim}44.37\;ml/g$ of extrudates extruded using 3, 4 and 5 RSE, whose trend was highly related to the moisture content of RWB and the extrusion pressure. Multiplication of IV and soluble solid (SS) content exhibited good correlation $(R^2=0.85)$ with specific mechanical energy (SME). The results suggested that SS and molecular size are an important factor governed by the SME in solubilization of wheat bran. WHC increased with increasing feed rate and moisture content, while OHC decreased. SDF increased from 2.68% of RWB to $4.32{\sim}6.48%$ of extruded wheat bran, indicating the significant breakdown of cell wall components. Microstructure of the extrudates showed the distinct patterns of degradation and solubilization of cell wall structure, depending on the moisture content of RWB.

• Journal of Korean Society of Steel Construction
• /
• v.18 no.2
• /
• pp.161-171
• /
• 2006

paper presents the results of a three-dimensional study of the natural vibration of laminated composite rectangular plates with various combinations of clamped and free boundaries. The Ritz method was used to obtain the stationary values of the associated Lagrangian, with displacements approximated using mathematicaly complete, characteristic orthogonal polynomials. The correctness of the three-dimensional model was established through a convergence study of the non-dimensional frequencies, followed by a comparison of the analytical findings in the existing literature. The wide scope of additional three-dimensional frequency results explains the influence of a number of geometrical and material parameters for angle-ply and cross-ply laminated plates, namely aspect ratio (${\mathcal{a/b}}$), thickness ratio (${\mathcal{a/h}}$), orthotropy of material, number of plies (${\mathcal{N}}$), fiber orientation angle (${\theta}$), and stacking sequence.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.7 no.1
• /
• pp.1-7
• /
• 2003

The carbon composite tube can play an important role in replacing or complementing longitudinal and transverse reinforcing steels by providing ductility and strength for conventional columns. In this study, both the experimental and analytical investigations of axial behavior of large-scale square concrete columns confined by carbon composite tube are presented. The specimens are filament-wound carbon composite with 90$^{\circ}$+30$^{\circ}$, 90$^{\circ}$+45$^{\circ}$ winding angle respect to longitudinal axis of tube. The instrumented large-scale concrete-filled composite tubes(CFCT) are subjected to monotonic axial loads exerted by 10,000kN UTM. The influence of winding angle, thickness of tube on stress-strain relationships of the confined columns is identified and discussed. Proposed equations to predict both the strength and ductility of confined columns by carbon composite tube demonstrate good correlation with test data obtained from large-scale specimens.

• Journal of the Korea Concrete Institute
• /
• v.25 no.6
• /
• pp.667-674
• /
• 2013

Improving the earthquake resistance of buildings through seismic retrofitting using steel braces can result in brittle failure at the connection between the brace and the building, as well as buckling failure of the braces. This paper proposes a new seismic retrofit methodology combined with glass fiber sheet (GFS) and non-compression X-brace system using carbon fiber (CFXB) for reinforced concrete buildings damaged in earthquakes. The GFS is used to improve the ductility of columns damaged in earthquake. The CFXB consists of carbon fiber bracing and anchors, to replace the conventional steel bracing and bolt connection. This paper reports the seismic resistance of a reinforced concrete frame strengthened using the GFS-CFXB system. Cyclic loading tests were carried out, and the hysteresis of the lateral load-drift relations as well as ductility capacities were investigated. Carbon fiber is less rigid than the conventional materials used for seismic retrofitting, resulting in some significant advantages: the strength of the structure increased markedly with the use of CF X-bracing, and no buckling failure of the bracing was observed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.5
• /
• pp.3602-3609
• /
• 2015

HPFRCC is characterized by a very low water-to-binder ratio which induce extremely large autogenous shrinkage at early age. The restriction of such autogenous shrinkage through the use of forms and reinforcing bars will increase substantially the risk of excessive residual stresses and shrinkage cracking. The exact understanding of the shrinkage behavior and studies on solutions to reduce shrinkage should be imperatively undertaken for further application of HPFRCC to real structures. Therefore, this paper investigated the mechanical properties of HPFRCC with respect to the eventual introduction of expansive admixture(EA) and shrinkage reducing agent (SRA) in the mixture. Autogenous shrinkage test was conducted considering the coefficient of thermal expansion (CTE) measured at early age so as to examine the effects of EA and SRA on the autogenous shrinkage behavior of HPFRCC.