• Proceedings of the KSME Conference
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• 2004.04a
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• pp.246-251
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• 2004

Nano-indentation is used for measuring mechanical properties of thin films such as elastic modulus and hardness. For ductile materials, pile-up around the indenter causes the calculation of inaccurate projected contact area. This phenomenon was found by measurement of indentation shape using an atomic force microscope. In present study finite element analysis of nano-indentation was performed to compensate the effects of pile-up on the contact area. The result of finite element analysis was compared with that of nano-indentation for a ductile material. The analysis has demonstrated that the true contact area is greater than that calculated by nano-indentation. It is verified that the consideration of the effects of pile-up in nanoindentation for ductile materials using the finite element method is reasonable.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.419-425
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• 2010

In order to examine the P.H.C pile raw material using glass forming ceramic. The used materials is ordinary portland cement, waste TFT-LCD glass powder and reactive agent(Ca$(OH)_2$). The first experiment is characteristics analysis of the waste TFT-LCD glass powder, For the second experiment is mortar and concrete compressive strength for using of the concrete file raw material for waste TFT-LCD glass powder. The results of experiment showed that the substitution ratio of 10% waste TFT-LCD glass powder and 1% reactive agent(Ca$(OH)_2$) was excellent at a point of view for the physical characteristic. The study's most important finding is that the recycling of waste TFT-LCD glass powder.

• Proceedings of the KAIS Fall Conference
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• 2004.06a
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• pp.172-175
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• 2004

This paper analyzes the effects of Ge profiles shape of SiGe heterojunction bipolar transistors (HBT's) for high frequency application. Device simulations using ATLAS/BLAZE for the SiGe HBT with trapezoidal or triangular Ge profile are carried out to optimize the device performance. An HBT with $15\%$ triangular Ge profile shows higher cut-off frequency and DC current gain than that with $19\%$ trapezoidal Ge profile. The cut-off frequency and DC gain are increased from 42GHz to 84GHz and from 200 to 600, respectively. The SiGe HBT has been fabricated using a production CVD reactor.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1150-1152
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• 2005

This paper deals with inductance profile of linear switched reluctance motor. Inductance profile of LSRM calculate at align and unalign position using magnetic equivalent circuit method. Magnetic equivalent circuit method of this paper used method of reference[3],[4], but this method used modification on account difference of design specification Also, analysis result compares with data that is derived through an experiment, and proved validity.

• The KIPS Transactions:PartA
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• v.13A no.1 s.98
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• pp.45-52
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• 2006

To perform on-line maintenance for Distributed Information System, it is indispensable to disseminate files to participant nodes in the network. When users' requests for file deployment occur simultaneously in a short period a deployment server falls into overload phase, which is often called Flash Crowds. h common solution to avoid Flash Crowds is to increase hardware capacity. In this paper, we propose a software solution based on P2P, which does not cost any additional expense. In the proposed solution, nodes in the network are grouped into subnetworks one of which is composed of only neighboring nodes. In each subnetwork, copies of deployment files can be transferred to each other. Consequently, it brings about the effect of load balancing in deployment server. To raise the effectiveness, target files for deployment are packed into one package. Before being transferred, each package is divided into multiple equal-sized segments. A deployment server in a normal phase transmits a package requested from nodes in segment units. However a deployment server is overloaded, if segments already exist in the subnetwork participant nodes in the subnetwork receive necessary segments from neighboring nodes. In this paper, we propose data structures and algorithm for this approach and show performance improvement through simulation.

• Clean Technology
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• v.19 no.2
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• pp.156-164
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• 2013

In this study, we analyzed the operational characteristics of a 0.25 MW methanation pilot plant. Isothermal reactor controled the heat released from methanation reaction by saturated water in shell side. Methanation process consisting of isothermal reactor and adiabatic reactor had advantages with no recycle compressor and more less reactors compared with methanation process with only adiabatic reactors. In case that $H_2$/CO ratio of syngas was under 3, carbon deposition occurred on catalyst in tube side of isothermal reactor and the pressure of reactors increased. In case that $H_2$/CO ratio was maintained around 3, no carbon deposition on catalyst in tube side of isothermal reactor was found by monitoring the differential pressure of reactors and by measuring the differential pressure of several of tubes filled with catalyst before and after operating. It was shown that CO conversion and $CH_4$selectivity were over 99, 97%, respectively, and the maximum $CH_4$productivity was $695ml/h{\cdot}g-cat$.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.3
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• pp.32-43
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• 2010

This paper presents deblocking filter for low-complexity video decoder. Baseline profile of the H.264/AVC used for mobile devices such as mobile phones has two times higher compression performance than the MPEG-4 Visual but it has a problem of serious complexity as using 1/4-pel interpolation filter, adaptive entropy model and deblocking filter. This paper presents low-complexity deblocking filter for decreasing complexity of decoder with preserving the coding efficiency of the H.264/AVC. In this paper, the proposed low-complexity deblocking filter decreased 49% of branch instruction than conventional approach as calculating value of BS by using the CBP. In addition, a range of filtering of strong filter applied in intra macroblock boundaries was limited to two pixels. According to the experimental results, the proposed low-complexity deblocking filter decreased -0.02% of the BDBitrate comparison with baseline profile of the H.264/AVC, decreased 42% of the complexity of deblocking filter, and decreased 8.96% of the complexity of decoder.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3653-3659
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• 2009

Inter-prediction is always the main bottleneck in H.264/AVC baseline profile. This paper describes an efficient inter-prediction hardware architecture design. H.264/AVC decoder supports various block types but reference software considers only the $4{\times}4$ block when the reference block is being fetched. This causes duplicated pixels which needs extra fetch cycles. In order to eliminate some of the duplicated pixels, the $8{\times}8$ and $4{\times}4$ blocks were considered in the previous design. If the block size is larger than or equal to the $8{\times}8$ block, it will be decomposed into several $8{\times}8$ blocks and if the block size is smaller than the $8{\times}8$ block it will be decomposed into several $4{\times}4$ blocks. Comparing with the reference software, the maximum and minimum cycle reduction of the previous design are 41.5% and 28.2% respectively. For further reduction of the fetch cycles, the various block types are considered in this paper. As a result, the maximum cycle reduction is 18.6% comparing with the previous design.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.198-199
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• 2013

본 논문에서는 리튬공기(Li-Air) 배터리를 소개하고 전기화학적 특성분석을 간단히 진행하였다. 우선, 리튬공기 배터리의 동작원리를 소개하고 기존 리튬이온(Li-Ion) 배터리와의 차이점을 제시하였다. 각 만방전압에 따른 배터리의 전기화학적 특성분석을 위해 방전용량 및 임피던스 특성커브를 분석하였다. 더불어, 향후 State-of-charge(SOC) 추정을 위한 데이터를 위해 Open-circuit voltage(OCV) 및 실제 충방전 전류 프로파일에 따른 충방전 전압을 분석하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06a
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• pp.319-320
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• 2008