• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.97-98
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• 2010

This paper discusses shear behavior of Joint with premix mortar and strain hardening cement composites(SHCC) with PVA and PE fibers. The main variables considered include the type of cement composites(premixed mortar, SHCC with hybrid fiber) and reinforcement. It was evaluated that shear load had a good accordance with the test and equation result.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.175-176
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• 2009

연성 기판을 기초로 하는 플렉서블 디스플레이 등의 연성 소자에 적용되는 TCO, 투습방지막의 기계적 특성을 시험하였다. 실제 사용 환경에서의 기계적 특성을 평가하기 위하여 굽힘시험과 인장시험을 적용하였다. PET 기판위에 PE-CVD 공정으로 성장된 실리콘 산화물 ($SiO_x$) 박막과 그 위에 스퍼터링 공정으로 성장된 투명 전도성 산화물 (TCO, Transparent Conducting Oxide) 박막의 시험 결과, 균열 생성 임계 변형량은 TCO 박막에 의해서 결정됨을 알 수 있었다. 따라서 향상된 기계적 특성을 얻기 위해서는 TCO 박막의 특성 제어가 필요하다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5A
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• pp.702-708
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• 2000

In this paper, we designed one-dimensional VLSI array with optimal pipeline period for high speed processing fractal image compression. The algorithm is derived which is suitable for VLSI array from axed block partition algorithm. Also the algorithm satisfies high quality of image and high compression-ratio. The designed VLSI array has optimal pipeline relied because the required processing time of PEs is distributed as same as possible. As this result, we can improve the processing speed up to about 3 times. The number of input/output pins can be reduced by sharing the input/output and arithmetic unit of the domain blocks and the range blocks.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.9
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• pp.86-94
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• 1998

This paper proposes a new fast block-matching algorithm, named MFSS(Modified Four-Step Search) algorithm, which has better performance and is more adequate for hardware realization than the existing fast algorithms. The proposed algorithm is suitable for hardware realization since it has a unique regularity during the search procedure. It is shown from simulation results that its performance is close to that of FS(Full Search) algorithm. This paper also proposes a VLSI architecture and presents some design results of a motion estimator and compensator which adopted the MFSS algorithm. The important aspects considered in designing a motion estimator and compensator are hardware complexity of design results, and total delay needed to generate the motion compensated data after finding the motion vectors. Hardware complexity is minimized by using just nine PE(Process Element)'s, and total delay is minimized by sharing search memory of the motion estimator and compensator.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.49-56
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• 2015

Ultra-High Strength Concrete(UHPC) has ultra-high material performance including high strength and high flowability. On the other hand it is less ductile than high ductile fiber reinforced cementitious composite. This study investigated the effect of combination of steel fiber and micro fiber on the tensile behavior of UHPC. Four types of UHPC containing combination of steel fiber, polyethylene(PE), polyvinyl alcohol(PVA), and basalt fiber were designed. And then uniaxial tension tests were performed to evaluate the tensile behavior of UHPC according to combination of fibers. And density was measured to evaluate whether micro fiber induces unintentional high pore or not. From the test results, it was exhibited that PE fiber with high strength is effective to improve the tensile behavior of UHPC and basalt fiber is effective to increase the cracking and tensile strength of UHPC. Furthermore, it was also verified that micro fiber does not make high pore.

• Membrane Journal
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• v.33 no.5
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• pp.257-268
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• 2023

Membrane capacitive deionization (MCDI) is a variation of the conventional CDI process that can improve desalination efficiency by employing an ion-exchange membrane (IEM) together with a porous carbon electrode. The IEM is a key component that greatly affects the performance of MCDI. In this study, we attempted to derive the optimal fabricating factors for IEMs that can significantly improve the desalination efficiency of MCDI. For this purpose, pore-filled IEMs (PFIEMs) were then fabricated by filling the pores of the PE porous support film with monomers and carrying out in-situ photopolymerization. As a result of the experiment, the prepared PFIEMs showed excellent electrochemical properties that can be applied to various desalination and energy conversion processes. In addition, through the correlation analysis between MCDI performance and membrane characteristic parameters, it was found that controlling the degree of crosslinking of the membranes and maximizing permselectivity within a sufficiently low level of membrane electrical resistance are the most desirable membrane fabricating condition for improving MCDI performance.

• Progress in Medical Physics
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• v.20 no.3
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• pp.125-131
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• 2009

In this study, the paclitaxel eluting stent (PES) was prepared by coating a biliary stent with paclitaxel using various biopolymer such as poly (vinyl acetate) (PVAc), poly (lactic-co-glycolic acid) (PLGA), Silicone rubber for restenosis prevention in gastrointestinal disease by a dip-coating method. Drug contents of PES were increased as surface area of stent, concentration and molecular weight of coating polymer increase. In $^1H-NMR$ specta, we know that drug did not change by confirming specific peaks of paclitaxel in PES. As shown in SEM image, PES prepared using various biopolymer is coated clearly and regularly except Silicone rubber coating polymer. In in vitro cell cytotoxicity test, bare stent showed low cytotoxic effect against CT-26 colon carcinoma cell line on 3 day. However, PES coated with PLGA 502H showed the highest cytotoxicity because PLGA 502H is biodegradable polymer and has less molecular weight than other coating polymer. These results suggest that PES coated various biopolymer can be prevented restenosis in gastrointestinal disease.

• Membrane Journal
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• v.30 no.4
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• pp.228-241
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• 2020

Separators, which produces physical layer between a cathode and anode, are getting enormous attention as the quality of the separator determines the performance of lithium ion batteries (LIBs). Porous membranes based on polyethylene (PE) and polypropylene (PP) are generally utilized as the separator of LIBs because of their high electrochemical stability and suitable mechanical strength. However, low thermal resistance and wettability of PE and PP membranes limited the potential of LIBs. Operating at the temperature exceeding the melting point of membranes, the separators change their structures which lead to short circuit of LIBs. Low wettability of the separators corresponds to low ionic conductivity which increases the cell resistance. To overcome these weaknesses of PE and PP separators, different types of separator were prepared by co-electrospinning, applying coating layer, forming core shell around membrane, and papermaking method. The synthesized separator greatly enhanced the heat resistance and wettability of separator and mechanical properties like flexibility and tensile strength. In this review different type of polymer membrane used as separator in lithium ion battery are discussed.

• Journal of Korea Water Resources Association
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• v.40 no.1 s.174
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• pp.89-99
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• 2007

Uncertainty analysis is used to eliminate the climatic variables of input nodes and construct the model of an optimal type from COMBINE-GRNNM-GA(Type-1), which have been developed in this issue(2007). The input variable which has the lowest smoothing factor during the training performance, is eliminated from the original COMBINE-GRNNM-GA (Type-1). And, the modified COMBINE-GRNNM-GA(Type-1) is retrained to find the new and lowest smoothing factor of the each climatic variable. The input variable which has the lowest smoothing factor, implies the least useful climatic variable for the model output. Furthermore, The sensitive and insensitive climatic variables are chosen from the uncertainty analysis of the input nodes. The optimal COMBINE-GRNNM-GA(Type-1) is developed to estimate and calculate the PE which is missed or ungaged and the $ET_r$ which is not measured with the least cost and endeavor Finally, the PE and $ET_r$. maps can be constructed to give the reference data for drought and irrigation and drainage networks system analysis using the optimal COMBINE-GRNNM-GA(Type-1) in South Korea.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.89-92
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• 2008

The seismic behavior of the lightly reinforced concrete frames (LRCFs) was controlled by the nonductile behavior of the critical regions. These critical regions require retrofit to improve the seismic behavior of the lightly reinforced concrete frames. Critical column end regions must be retrofit to increase the global ductility capacity. The objective of this research is to evaluate structural strengthening performance of lightly reinforced concrete frame with Strain hardening cement composite(SHCC) experimentally. The experimental investigation consisted of a cyclic load tests on 1/3-scale models of precast infill walls. Reinforcement detail of infill wall was variables in the experiment. The experimental results, as expected, show that the multiple crack pattern, strength, ductility and energy dissipation capacity are superior for specimen with SHCC infill wall due to bridging of fibers and stress redistribution in cement matrix.