• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.04a
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• pp.126-127
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• 2007

AZ91D 마그네슘합금상에 MAO방법을 통한 산화막 성장에 관해 연구하였다. 주요 처리조성물은 NaOH, $Na_3\;C_6H_5O_7$, $Na_4\;P_2\;O_7$이며, 양극에 Mg 샘플을, 음극에 스텐레스 플레이트를 고정하여 설치후 인가전압 50V, 2분간에 걸쳐 Mg 표면에 Micro arc에 의한 산화막이 성장되었다. 산화막 측정 결과 20회 시행후 평균 15.5um 두께를 가졌으며, 막 성장후 표면은 균일하였으며, 밝은 갈색을 띄었다. 염수농도 5%의 염수분무테스트에서는 72시간 경과후에도 5%이내의 우수한 내부식성을 보였다.

• Bulletin of the Korean Chemical Society
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• v.15 no.6
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• pp.502-506
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• 1994

The results of kinetic studies on the reactions of 2-phenyl-l-propyl arenesulfonates with anilines and benzylamines in methanol at $55.0^{\circ}C$ are reported. The transition state variation with the substituents in the nucleophile (X) and leaving group (Z) is in accord with that expected from a negative ${\sigma}_{XZ}$ value. A stronger nucleophile and nucleofuge lead to a greater extent of bond-making and -breaking. Somewhat greater magnitude of ${\sigma}_{XZ}$ compared to the nearly constant value for the similar processes at a primary carbon atom has been interpreted to result from a partial contribution of the concurrent frontal displacement path.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11b
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• pp.565-570
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• 1996

$^{32}$P는 순수한 $\beta$$^{-}$ 방출핵종(방출에너지 ＝ 1.71 MeV, 반감기 ＝ 14.3일)이며 의료용, 표지화합물 합성용, 유전공학 실험용 등으로 널리 사용되므로 고품질의 $^{32}$P의 수요에 부응하기 위해 감압증류법을 개발하였는 바 그 방법과 결과는 다음과 같다. 연구로 2호에서 중성자 조사된 황 표적을 감압 증류용기내에서 5~10 mmHg의 감압하에 200~30$0^{\circ}C$로 가열하여 황을 증류해 낸 다음 묽은 염산을 역류시켜 넣고 $^{32}$P 를 울궈냈다. 이 용액을 이온교환 수지로 정제하여 약 60 mCi/batch의 정제 $^{32}$P를 얻었다. 이온교환수지에 흡착되는 $^{32}$P의 방사능은 전체의 3% 미만이었고 여기에 흡착되는 불순 핵종은 $^{131}$ Ba, $^{85}$ Sr, $^{59}$ Fe, $^{65}$ Zn, $^{60}$Co이었다. 이 방법으로 얻은 $^{32}$P 최종제품은 핵종순도 >99%, 방사화학적 순도 >98%, 고형성분 함량 <1.2 mg/mL 이어서 그 품질이 우수함을 알 수 있었다.

• Bulletin of the Korean Mathematical Society
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• v.56 no.3
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• pp.745-756
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• 2019

We obtain Lipschitz type characterization and double integral characterization for Fock-type spaces with the norm $${\parallel}f{\parallel}^p_{F^p_{m,{\alpha},t}}\;=\;{\displaystyle\smashmargin{2}{\int\nolimits_{{\mathbb{C}}^n}}\;{\left|{f(z){e^{-{\alpha}}{\mid}z{\mid}^m}}\right|^p}\;{\frac{dV(z)}{(1+{\mid}z{\mid})^t}}$$, where ${\alpha}>0$, $t{\in}{\mathbb{R}}$, and $m{\in}\mathbb{N}$. The results of this paper are the extensions of the classical weighted Fock space $F^p_{2,{\alpha},t}$.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.11a
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• pp.163-164
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• 2018

본 논문에서는 양방향 예측 모드에서 LIC(Local Illuminance Compensation)의 복잡도 감소를 위한 방법을 제안한다. 제안하는 방법은 현재 CU 가 양방향 예측 모드일 경우 움직임 보상 단계에서 예측 블록 두 개를 가중 평균을 낸 뒤 LIC 를 수행함으로써 양방향 예측모드에서 LIC 를 한번만 수행하여 기존 LIC 대비 낮은 복잡도를 보인다. 제안하는 방법의 성능 평가를 위하여 RA(Random Access) 조건에서 MPEG 표준 실험 영상의 B, C, D 클래스를 이용하여 BD-rate 를 VTM-2.0.1 과 비교한다. 실험결과로서 본 논문에서 제안하는 방법이 VTM2.0.1 대비 BD-rate 성능 관점에서 Y, U, V 각각에 대하여 평균 0.17, 0.17, 0.23 의 성능 향상을 보인다.

• Transactions of Materials Processing
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• v.31 no.2
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• pp.81-88
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• 2022

Numerical analysis and dynamic material properties are required to analyze the behavior of workpiece during an electrohydraulic forming (EHF) process. In this study, EHF experiments were conducted under three conditions (6, 7, 8 kV). Dynamic material properties of Al 5052-H34 were inversely estimated through an ANN (Artificial Neural Network) model constructed based on LS-Dyna analysis results. Parameters of Cowper-Symonds constitutive equation, C and p, were used to implement dynamic material properties. By comparing experimental results of three conditions with ANN model results, optimized parameters were obtained. To determine the reliability of the derived parameters, experimental results, LS-Dyna analysis results, and ANN results of three conditions were compared using MSE and SMAPE. Valid parameters were obtained because values of indicators were within confidence intervals.

• Journal of Korean Vacuum Science & Technology
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• v.5 no.2
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• pp.38-42
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• 2001

We investigated physical properties of ion-beam mixed Fe/si multilayerd films(MLF) prepared by rf sputtering onto glass substrates at room temperature. Such an ion-beam treatment has led to noticeable changes in the structural and physical properties of the MLF: the formation of a new phase which is characterized by a crystalline silicide with a low coercivity and Tc = 550 K. In contrast to the as-prepared state, the ion-beam mixed MLF contains two magnetic phases. One of them is a very soft (Hc < 2 Oe), but microscopically homogeneous one with M$\sub$eff/=6.7 kG.

• International Journal of Computer Science & Network Security
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• v.23 no.11
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• pp.73-76
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• 2023

We introduce DCNN and DRAE appraoches for compression of medical videos, in order to decrease file size and storage requirements, there is an increasing need for medical video compression nowadays. Using a lossy compression technique, a higher compression ratio can be attained, but information will be lost and possible diagnostic mistakes may follow. The requirement to store medical video in lossless format results from this. The aim of utilizing a lossless compression tool is to maximize compression because the traditional lossless compression technique yields a poor compression ratio. The temporal and spatial redundancy seen in video sequences can be successfully utilized by the proposed DCNN and DRAE encoding. This paper describes the lossless encoding mode and shows how a compression ratio greater than 2 (2:1) can be achieved.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.5
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• pp.298-302
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• 2016

In this work, $LiMn_2O_4$ and $LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$ cathode materials are mixed by some specific ratios to enhance the practical capacity, energy density and cycle performance of battery. At present, the most used cathode material in lithium ion batteries for EVs is spinel structure-type $LiMn_2O_4$. $LiMn_2O_4$ has advantages of high average voltage, excellent safety, environmental friendliness, and low cost. However, due to the low rechargeable capacity (120 mAh/g), it can not meet the requirement of high energy density for the EVs, resulting in limiting its development. The battery of $LiMn_2O_4-LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$ (50:50 wt%) mixed cathode delivers a energy density of 483.5 mWh/g at a current rate of 1.0 C. The accumulated capacity from $1^{st}$ to 150th cycles was 18.1 Ah/g when the battery is cycled at a current rate of 1.0 C in voltage range of 3.2~4.3 V.

• Journal of the Korean Applied Science and Technology
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• v.11 no.2
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• pp.121-127
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• 1994

1-(2-hydroxyethyl)-2-undecyl-2-imidazoline[I] was converted into various types of sulfonated or sulfated amphoteric surfactants as following. 1-(2-hydroxyethyl)-1-(3-sulfonatedpropyl)-2-undecyl-2-imidazolium[III] 1-(2-sulfatedethyl)-1-methyl-2-undecyl-2-imidazolium[IV] 1-dioxylethylene methyl sulfonated-1-methyl-2-undecyl-2-imidazoliun[V] N-[N'-(2-hydroxyethyl)-N-(3-sulfonatedpropylammonio]ethyl dodecanoyl amide[VI] Mono sodium N-[N'-(2-hydroxyethyl)-N'-disulfonatedpropylammonio]ethyl dodecanoyl amide[VII] N-[N'-(2-hydroxyethyl-N'-(2-hydroxypropl-N'(3-sulfonatedpropyl)ammonio] ethyl dodecanoyl amide[VIII] The alkylimidazolines could be readily hydrolyzed to give amidoamines, but by quaternerization, hydrolysis stability of imidazoline and amide type amphoteric surfactantes were increased in the alkali and acid conditions. Also, at least three carbon chains introduce to the main group, water solubility was sparingly increased.