Garment skin leather 표면 코팅에 사용된 폴리우레탄 수지는 polyethylene glycole(PEG)의 함유를 [NCO]/[OH] mole % 비로 달리하면서 합성하였으며, 합성된 폴리우레탄 수지의 기계적 특성은 SEM, FT-IR, UTM 등을 이용하여 측정하였다. 비이온성을 띄고 있는 PEG(poly ethylene glycol)의 [NCO]/[OH] mole % 비가 증가함에 따라 내굴곡성(건식, 습식)의 변화는 없었으며, 내마모도, 인장강 도수치가 낮아짐을 알 수 있었다. 반대로 연신율 물성은 증가함을 알 수 있었다. 점도 변화 측정 결과에 는 PEG의 [NCO]/[OH] mole % 증가에 따라 점도가 묽어짐을 알 수 있었다.

Nanosized and aggregated Y2O3:Eu Red phosphors were prepared by template method from metal salt impregnated into crystalline cellulose. The particle size and photoluminescent property of Y2O3:Eu red phosphors were controlled by variation of the calcination temperature and time. Dispersed nanosol was also obtained from the aggregated Y2O3:Eu Red phosphor under bead mill wet process. The dispersion property of the Y2O3:Eu nanosol was optimized by controlling the bead size, bead content ratio and milling time. The median particle size (D50) of Y2O3:Eu nanosol was found to be around 100 nm, and to be below 90 nm after centrifuging. In spite of the low photoluminescent properties of Y2O3:Eu nanosol, it was observed that the photoluminescent property recovered after re-calcination. The dispersion and photoluminescent properties of Y2O3:Eu nanosol were investigated using a particle size analyzer, FE-SEM, and a fluorescence spectrometer.

Zirconia nanoparticles were widely used as filler in order to get high refractive index layer. However, dispersion of nanoparticles is difficult due to their agglomeration in solvent. In this study, the dispersibility of the zirconia suspension is promoted by controlling the steric hindrance and electrostatic interactions through the adsorption of PEI according to alkali treatment time. Also, to induce improved dispersibility on suspension, we changed the dispersion conditions variously and fabricated an ink formulation method for the coating layer. Zirconia suspension was characterized by dynamic light scattering (DLS), Zeta potential measurement, Transmission Electron Microscope (TEM) and FT-IR. We were able to confirm that good dispersion of zirconia suspension by alkali treatment and PEI led to high refractive index.

Magnesium alloy is becoming known for the lightest material in the metallic materials. Recently the automotive industry has a variety application to the light weight parts replacement. This study focuses on the mechanical property improving through a tiny amount’s CNT addition into the magnesium alloy as AM60. The CNT material is an arduous combination of the metallic materials. Therefore this study is concentrating on the contact force growth for the CNT material. Consequently, the made CNT is produced by the CVD process using the magnesium catalyst. The CNT material has dispersive with mechanical process into the molten AM60 alloy. The mechanical experiment result that hardness is 18% increasing and tensile strength is 13% increasing, better than the raw AM60 alloy on this investigation.

Al2O3 nanosol dispersed under ethanol or N-Methyl-2-pyrrolidone(NMP) was studied and optimized with various dispersion factors and by utilizing the silane modification method. The two kinds of Al2O3 powders used were prepared by thermal decomposition method from aluminum ammonium sulfate(AlNH4(SO4)2) while controlling the calcination temperature. Al2O3 sol was prepared under ethanol solvent by using a batch-type bead mill. The dispersion properties of the Al2O3 sol have a close relationship to the dispersion factors such as the pH, the amount of acid additive(nitric acid, acetic acid), the milling time, and the size and combination of zirconia beads. Especially, Al2O3 sol added 4 wt% acetic acid was found to maintain the dispersion stability while its solid concentration increased to 15 wt%, this stability maintenance was the result of the electrostatic and steric repulsion of acetic acid molecules adsorbed on the surface of the Al2O3 particles. In order to observe the dispersion property of Al2O3 sol under NMP solvent, Al2O3 sol dispersed under ethanol solvent was modified and solventexchanged with N-Phenyl-(3-aminopropyl)trimethoxy silane(APTMS) through a binary solvent system. Characterization of the Al2O3 powder and the nanosol was observed by XRD, SEM, ICP, FT-IR, TGA, Particles size analysis, etc.

The sol-gel method is the simplest method for synthesizing monodispersed silica particles. The purpose of this study is to synthesize uniform, monodisperse spherical silica nanoparticles using tetraethylorthosilicate (TEOS) as the silica precursor, ethanol, and deionized water in the presence of ammonia as a catalyst. The reaction time and temperature and the concentration of the reactants are controlled to investigate the effect of the reaction parameters on the size of the synthesized particles. The size and morphology of the obtained silica particles are investigated using transmission electron microscopy and particle size analysis. The results show that monodispersed silica particles over a size range of 54-504 nm are successfully synthesized by the sol-gel method without using any additional process. The nanosized silica particles can be synthesized at higher TEOS/H2O ratios, lower ammonia concentrations, and especially, higher reaction temperatures.

결정성 탄소물질은 결합의 형태에 따라 carbyne (sp1, 1D 구조), graphite (sp2+π, 2D), diamond (sp3, 3D) 구조 로 나뉜다. 특히 sp2 결합에 기반한 나노물질은 fullerene (0D), 탄소나노튜브 (1D or quasi-2D), 그래핀 (2D) 으로 나뉜 다. 탄소나노튜브와 그래핀은 물리적으로 여러 가지 뛰어난 특성이 있어 구조재나 광전자 재료, 멤브레인 등 다양한 분 야에 응용가치가 높다. 하지만 이들 나노재료는 강하게 응집되는 성질이 있어 용액에 분산할 필요가 있다. 특히 이는 용 액 상에서 박리, 안정화의 과정을 거쳐야 안정적으로 분산된 상태를 유지할 수 있다. 본 고에서는 탄노나노튜브나 그래 핀이 용매에서 박리되어

본 연구의 목적은 트리아세테이트와 흡한속건성 PET 합연사로 구성된 복합직물의 염착량 증진 및 동일색상 염색 (union dyeing)을 위한 최적 혼합염색 조건을 찾는 것이다. 이를 위하여 E-type 분산염료(C.I. Disperse red 50)와 S-type 분산염료(C.I. Disperse red 92)를 혼합하여 1욕 혼합염색으로 염색온도, 염색시간, 염료의 혼합비율에 따른 염색직물의 흡진율, 염착율, 색상 및 색차를 측정하였다. 혼합염색의 염착평형은 100℃에서 일어났으나 염색된 직물의 K/S 값과 겉보기 색상을 비교해보았을 때 트리아세테이트와 흡한속건성 PET의 색이 동일한 색으로 발현되는 온도는 120℃임을 확인하였다. 염색 시간 증가에 따른 혼합염료 흡진율과 염착량의 변화는 크게 나타나지 않았으나 염색시간이 길수록 그리고 혼합염료를 사용할 경우 균일한 색상을 얻을 수 있었다. E-type에 S-type염료의 혼합비율을 적절히 조절하여 혼합염색 하면 단독염색 보다 E-type 염료의 색상과 차이 없이 염착량을 증대시킬 수 있었다.

Distributed genetic algorithm (DGA), also known as island model or coarse-grained model, is a kind of parallel genetic algorithm, in which a population is partitioned into several sub-populations and each of them evolves with its own genetic operators to maintain diversity of individuals. It is known that DGA is superior to conventional genetic algorithm with a single population in terms of solution quality and computation time. Several researches have been conducted to evaluate effects of parameters on GAs, but there is no research work yet that deals with structure of DGA. In this study, we tried to evaluate performance of various genetic algorithms (GAs) for the famous symmetric traveling salesman problems. The considered GAs include a conventional serial GA (SGA) with IGX (Improved Greedy Crossover) and several DGAs with various combinations of crossover operators such as OX (Order Crossover), DPX (Distance Preserving Crossover), GX (Greedy Crossover), and IGX. Two distinct immigration policies, conventional noncompetitive policy and newly proposed competitive policy are also considered. To compare performance of GAs clearly, a series of analysis of variance (ANOVA) is conducted for several scenarios. The experimental results and ANOVAs show that DGAs outperform SGA in terms of computation time, while the solution quality is statistically the same. The most effective crossover operators are revealed as IGX and DPX, especially IGX is outstanding to improve solution quality regardless of type of GAs. In the perspective of immigration policy, the proposed competitive policy is slightly superior to the conventional policy when the problem size is large.

본 연구에서는 최근 분리, 흡착과 같은 물리적인 수처리 공정이 중요해짐에 따라 Track-etched polycarbonate(PC) membrane이 친수성이며 균일한 기공크 기를 가지고 기계적 강도가 우수하다는 점을 이용하여 표면이 하전되어있는 입자를 포함한 콜로이드 용액의 제거능력에 대해 조사형 분리 특성을 파악하였다. 유화중합을 이용하여 각각 양전하, 음전하로 각각 하전된 균일하며 착색된 나노 입자(70 ~200nm)를 제조하고, SEM, DSC, FT-IR 및 제타 전위를 측정하여 라텍스의 특성을 파악하였다. 이후 PC membrane의 표면전하 및 기공크기와 입자의 표면전하 및 입자크기에 따른 수투과도 및 배제율을 조사하였다.

생체 내 필수 영양소이자 영양 보충제 성분인 아연과 철은 수용액 상에서 분산 안정성이 낮으며, 철의 경우 주변 환경의 영향으로 쉽게 산화되는 특성을 가지고 있다. 최근에는 이러한 문제점을 보완하기 위해 나노 기술을 이용한 식품 개발이 이루어지고 있는데, 본 연구에서 사용 된 소재인 SunActive Zn 및 SunActive Fe는 나노 크기의 식품용 아연과 철을 친수성 폴리머로 코팅함으로써 분산 안정성, 수용액상 용해도 및 관능 특성을 향상시켰으나 그에 따른 독성 및 흡수율에 대한 연구는 미비한 실정이다. 따라서 본 연구에서는 랫드에 28일 반복 경구투여에 의한 독성시험 을 수행하였으며, 약동학적 연구를 통해 흡수율을 규명하고자 하였다. 비교 연구를 위해 대조 물질로 산화아연(ZnO, 100 nm) 나노물질 및 ferric pyrophosphate를 각각 사용하였다. 그 결과 SunActive Zn 및 SunActive Fe는 반복투여에 의한 유의적 독성 현상을 보이지 않았으며, 폴리머 코팅에 의해 아연 및 철의 체내 흡수율이 향상될 수 있는 것으로 나타났다. 이와 같은 연구 결과는 기능성 성분 및 체내 필수 영양분의 흡수율을 향상시키기 위한 새로운 개발 전략 을 제시한다.

The objective of this study is to investigate patent trends of Daegu city which tries to introduce environment friendly energy and to develop new technology or new industry sprung from technology convergence on smart decentralized energy technology and other technologies. After applying network analysis to corresponding groups of technology or industry convergence, strategy for future energy convergence industry is provided. Patent data applied in Daegu city area are used to obtain research goal. The technology which contains several IPC codes (IPC Co-occurrence) is considered as a convergence technology. Path finder network analysis is used for visualizing and grouping by using IPC codes. The analysis results categorized 13 groups in energy convergence industry and reclassified them into 3 cluster groups (Smart Energy Product Production Technology Group, Smart Energy Convergence Supply Technology Group, Smart Energy Indirect Application Technology Group) considering the technical characteristics and policy direction. Also, energy industry has evolved rapidly by technological convergence with other industries. Especially, it has been converged with IT industry, and there is a trend that energy industry will be converged with service industry and manufacturing industry such as textile, automobile parts, mechanics, and logistics by employing infrastructure as well as network. Based on the research results on core patent technology, convergence technology and inter-industry analysis, the direction of core technology research and development as well as evolution on decentralized energy industry is identified. By using research design and methodology in this study, the trend of convergence technology is investigated based on objective data (patent data). Above all, we can easily confirm the core technology in the local industry by analyzing the industrial competitiveness in the macro level. Based on this, we can identify convergence industry and technology by performing the technological convergence analysis in the micro level. 1

It is important to select proper ground motions for obtaining accurate results from response history analyses. The purpose of this study is to propose an accurate and efficient method that does not require excessive computation for selecting and scaling ground motions to match target response spectrum mean and variance. The proposed method is conceptually simple and straightforward, and it does not use a simulation algorithm that requires a sophisticated subroutine program. In this method, the desired number of ground motions are sequentially scaled and selected from a ground motion library. The proposed method gives the best selection results using Sum of Square Error and has the smallest value(=0.14). Also, The accuracy and consistency of the proposed method are verified by comparing the selection results of the proposed method with those of existing methods.

다양한 질량비의 SiO2, Hollow SiO2 나노 파티클들을 Poly(methylmethacrylate) (PMMA) 용액에 분산하여 OLED 내부 광추출용 산란층을 제작 하였다. 구형의 실리카 나노 파티클들은 약 300 nm의 평균 입자 사이즈를 나타내었다. 실리카 나노 파티클 고분자 분산액은 스핀코팅을 통하여 기판위에 코팅 되어 제작되었다. 내부가 비어 있지 앉은 SiO2 나노 파티클 산란층의 경우 높은 산란 특성을 나타내었으며 (30wt%, 588 nm, Haze 0.37) Hollow SiO2 나 노 파티클의 경우 상대적으로 낮은 산란 특성을 나타내는 것을 확인할 수 있었다 (30 wt%, 588 nm, Haze 0.16). 하 지만 Hollow SiO2 나노 입자의 경우 매우 낮은 back-scattering으로 인한 높은 투과 특성을 나타내었다 (30 wt%, 588 nm, 85%). 또한 입자의 함량 증가에 따른 투과도의 감소와 산란의 증가 비가 상대적으로 매우 높음을 확인할 수 있었다.

To study the dispersion factors of silica sol prepared from fumed silica powder, we prepared silica sol under an aqueous system using a batch type bead mill. The dispersion properties of silica sol have a close relationship to dispersion factors such as pH, milling time and speed, the size and amount of zirconia beads, the solid content of fumed silica, and the shape and diameter of the milling impellers. Especially, the silica particles in silica sol were found to show dispersion stability on a pH value above 7, due to the electrostatic repulsion between the particles having a high zeta potential value. The shape and diameter of the impellers installed in the bead mill for the dispersion of fumed silica was very important in reducing the particle size of the aggregated silica. The median particle size (D50) of silica sol obtained after milling was also optimized according to the variation of the size and amount of the zirconia beads that were used as the grinding medium, and according to the solid content of fumed silica. The dispersion properties of silica sol were investigated using zeta potential, turbiscan, particle size analyzer, and transmission electron microscopy.

PPG와 PTMG의 몰비를 달리하면서 첨가하여 합성된 폴리우레탄 수지의 물리적 특성을 SEM, FT-IR, UTM 을 이용하여 측정하였다. 본 연구를 통해 4개의 메틸렌기를 포함한 PTMG의 몰비 가 증가함에 따라 내마모도(60.26 mg.loss), 인장강도(5.24 kgf/㎟)가 증가함을 알 수 있었다. 반대로 연 신율(297 %)은 감소함을 확인 할 수 있었으며. 톨루엔을 이용한 내용제성 물성측정 결과로부터 PTMG 의 반응 몰비 증가에 따른 물성 증감 효과는 없었다. 또한 PTMG의 몰비가 증가함에 따라 점도(4.8 cp) 가 상승함을 확인 할 수 있었다.

This study is the sequel of a companion paper (I. Algorithm) for assessment of the seismic performance evaluation of structure using ground motions selected by the proposed algorithm. To evaluate the effect of the correlation structures of selected ground motions on the seismic responses of a structure, three sets of ground motions are selected with and without consideration of the correlation structure. Nonlinear response history analyses of a 20-story reinforced concrete frame are conducted using the three sets of ground motions. This study shows that the seismic responses of the frames vary according to ground motion selection and correlation structures.

It is important to select an accurate set of ground motions when conducting linear and nonlinear response history analyses of structures. This study proposes a method for selecting ground motions from a ground motion library with response spectra that match the target response spectrum mean, variance and correlation structures. This study also has addressed the determination of an appropriate value for the weight factor of a correlation structure. The proposed method is conceptually simple and straightforward, and does not involve a simulation algorithm. In this method, a desired number of ground motions are sequentially selected from first to last. The proposed method can be also used for selecting ground motions with response spectra that match the conditional spectrum. The accuracy and efficiency of the proposed procedure are verified with numerical examples.

Buffalo leather 표면 코팅에 사용된 폴리우레탄 수지에 glycerol의 함유를 mole % 비로 달리 하면서 첨가 하였다. 합성된 폴리우레탄 수지의 기계적 특성은 SEM, FT-IR, UTM 등을 이용하여 측정 하였다. 친환경적인 고분자 수지의 관심이 고조됨에 따라 용제의 사용을 최소화한 buffalo leather 코팅에 사용되는 수분산 수지를 합성하였다. 지방족 3가 알콜인 glycerol의 mole % 비가 증가함에 따라 내마모 도, 인장강도가 감소함을 알 수 있었다. 반대로 연신율, 내굴곡 물성은 증가함을 알 수 있었다. Toluene 을 이용한 내용제성 물성측정 결과에는 glycerol의 mole % 증가에 따른 물성 증감 효과는 없었다.