• 한국표면공학회지
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• 제31권6호
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• pp.334-344
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• 1998

Yew coating pmccss t.o form a surface layer ol CrN phasc on mild steel (A81 1020!, AlSI Hi3, 1Cr-0.5Mo steel (ASTM A213 and Nickrl-base superalloy (Inconel 718) was developed. Surlaces of various alloys t,n.ateii by chromizing for the formation ol Cr diffusion layer was subsequently trcaled by plasma nitriding in order t.o form the hard CrS coating layer on the surfaces. This duplex plasma surface tri-atments of chromizing and plasma nitriding have induced a lormation of a duplex-lrcated surfacr hyer of approximat~ls 70-80 $\mu\textrm{m}$thickncss with a iargcly improved microiiardnrss up to approxiniateW 1500Hv(50gf). The main cause for the lage improvment in the surface hardncss is altribilted to [.he fact that CrN and $Fe_xN$ phases are created successfully by ccliromizins and plasma nilriding treatment. High tenipera1,urc wear resislance of the duplex-treated mild steel and HI3 steels at $600^{\circ}C$ was examined. Comparing the duplex-treated specimens with the specimens treated only by chromizing, the rcsults shovmi that, thc wear volume of the duplex-treated mild skcl and 1113 stcel aSt.er a wear test, at $600^{\circ}C$ were reduced hy a Iactor of 8 and 3, respectively. Characteristics of the CrS phase by duplrx treatment were compared with $CrN_x$,/TEX> film by ion plating and the wear behaviors of CrN film lormed by two different nroccsses arc nea.riy identical.

• Journal of Biosystems Engineering
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• 제35권4호
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• pp.224-230
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• 2010

The purpose of this study was to develop position control system of an electric actuator for automatic shuttle shifting of a tractor. The electric actuator was installed at the link of the forward-reverse gearshift of the tractor transmission, and controlled in the ranges of forward, neutral, and reverse positions. The position control system of the electric actuator was developed based on PID (Proportional Integral Derivative) controller and transfer function of the electric actuator. The coefficients of the PID controller were determined by Ziegler-Nichols (Z-N) method and optimized using simulation program. The prototype AMT (Automated Manual Transmission) test unit of the tractor was installed and used to evaluate the performance of the position control. The evaluation system for the control performance consisted of forward-reverse actuator, motor driver, and controller. The tests were conducted as the controlled positions of the actuator were changed from neutral position to forward, neutral, and reverse positions in sequence. The sequential tests were repeated 20 times. The operations of changing the gearshift were considered as the step response of the control system. Maximum overshoot, settling time, and steady-state error were analyzed. The results showed that performance of the position control system was reasonable and qualified. The maximum overshoots, the steady-state errors, and the settling times of the position control system were 10~20%, 1~5%, and 0.92~1.49 sec, respectively. The modifications of the electric actuator will be required to enhance the performance of position control during field operation.

• 한국통신학회논문지
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• 제30권12A호
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• pp.1174-1182
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• 2005

본 논문에서는 고속의 데이터 전송률(110Mbps${\~}$480Mbps)을 갖는 WPAN을 위해 IEEE802.15 TG3a의 표준안 중 하나로 제안된 MB-OFDM(Multi-Band OFDM) 시스템을 위한 새로운 채별 추정 기법을 제안한다. 제안한 추정기법은 타이밍 동기 등을 위해서 제시하고 있는 PS(Packet Synchronization)신호의 상관특성을 사용한 것으로 기존 LS(Least Square) 기반의 채널 추정 방법에 비해 잡음의 영향을 줄일 수 있는 장점이 있으며 채널 추정을 위해 만들어진 CE(Channel Estimation)신호를 사용하지 않아도 되기 때문에 프리엠블로 제시된 심볼의 수를 줄일 수 있는 장점이 있다. 성능분석을 위해 IEEE802.15 TG3a에서 제시하고 있는 S-V 채널하에서 기존의 방법과 제안한 채널추정 방법을 컴퓨터 모의실험 하였으며 그 결과 Eb/N0에서 약 1${\~}$1.5dB 정도의 성능을 향상시킬 수 있었다.

• The Plant Pathology Journal
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• 제16권6호
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• pp.306-311
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• 2000

A new strain of Cucumber mosaic virus (CMV) from easter lily (Lilium longiflorum), Ly2-CMV, was identified and compared to the well-characterized Mf-CMV (subgroupⅠ) and LS-CMV (subgroupⅡ) by host reaction in several indicator plants, dsRNA analysis, serological property, RT-PCR analysis, restriction enzyme profile of the PCR products and nucleotide sequence of coat protein (CP) gene. Remarkable differences in symptoms of Ly2-CMV were found between Mf-CMV or LS-CMV in tobacco plants and Datura stramoinium. Ly2-CMV induced small necrotic ringspots on the inoculated leaves of Nicotiana tabacum cvs. Xanthi nc and Burley 21 and D. stramonium, and failed to infect these species systemically. Of the indicator plants tested, N. benthamiana only reacted with systemic infection by inoculation of Lr2-CMV. In experiments of dsRNA analysis, serology and RT-PCR of CP gene, Ly2-CMV was come within subgroupⅠ CMV. However, restriction enzyme analysis of the PCR products using MspⅠ showed that Ly2-CMV was distinct to Mf-CMV. The CP gene of Ly2-CMV contains 657 nucleotides, and the nucleotide sequence is similar to that of Mf-CMV. There is also a high degree of conservation between their putative gene products in Ly2-CMV and Mf-CMV, with five amino acid changes in the 218 amino acids of the CPs.

• 한국잡초학회지
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• 제12권4호
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• pp.374-379
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• 1992

우리나라에서 재배(栽培)되거나 자생(自生)하는 약용식물(藥用植物) 28과(科)58종(種)에 대해 서 paraquat 추천량(推薦量) 0.8kg $ha^{-1}$에 대한 저항성(抵抗性)을 검정(檢定)하고, 지황(地黃)에 대한 paraquat의 약량별(藥量別), 처리(處理) 시기(時期) 및 횟수별, 그리고 타(他) 제초제(除草劑)들에 대한 영향(影響)을 조사(調査)하였다. 1. 58종(種의) 약용식물중(藥用植物中) paraquat에 저항성(抵抗性)을 보인 종(種)은 지황(地黃)뿐이었다. 2. 지황(地黃)은 paraquat 추천량(推薦量)의 4배량(倍量) 3.2kg $ha^{-1}$ 처리(處理)에서 무처리(無處理)와 거의 비슷한 생육(生育)을 나타냈으며, 4.8kg $ha^{-1}$에서도 10% 정도(程度)의 생육억제(生育抑制)를 보였다. 또한 추천량(推薦量) 0.8kg $ha^{-1}$ 처리(處理)는 2~8엽기(葉期)까지 지황(地黃)의 엽기(葉期)에 관계(關係)없이, 또한 3엽기(葉期)부터 20일(日) 간격(間隔)의 5회(回) 반복처리(反復處理)에서도 정상적(正常的)인 생육(生育)을 나타냈다. 3. 지황(地黃)은 glyphosate, 2,4-D, dicamba + 2, 4-D의 추천량(推薦量) 수준(水準) 처리(處理)에서는 완전(完全)히 고사(枯死)되었지만, paraquat 0.8kg $ha^{-1}$ 처리(處理)에서는 정상적(正常的)인 생육(生育)을 나타내어 생리적(生理的)인 선택성(選擇性)이 있음을 나타내었다.

• 한국잡초학회지
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• 제16권3호
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• pp.194-199
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• 1996

우리 나라 논에서 발생(發生)되는 논피와 돌피 그리고 식용피에 대하여 종자(種子) 크기와 초기(初期) 생육차이(生育差異)를 비교(比較)하고, 이들에 대한 피 방제용(防除用) 제초제(除草劑) molinate, esprocarb 및 mefenacet의 효과(效果)를 처리(處理) 엽기별(葉期別)로 검토(檢討)하였다. 논피 종자(種子)의 천립중(千粒重)은 돌피의 약 3배 정도 무거웠으나 식용피의 천립중(千粒重)과는 유의차(有意差)가 없었다. 파종후(播種後) 2.5엽기(葉期)에 도달하는데 식용피는 11일(日), 논피는 13일(日), 그리고 돌피는 14일(日)이 소요(所要)되었다. Molinate, esprocarb 및 mefenacet의 처리(處理)에 대하여 돌피는 논피에 비하여 보다 감수성(感受性)을 나타내었는데, 처리(處理) 엽기(葉期)의 진전(進展)과 함께 감수성(感受性)이 감소(減少)되었다. 한편 이들 제초제(除草劑)들에 대한 식용피의 반응(反應)은 1.5엽기(葉期)와 3.0엽기(葉期)사이의 처리(處理)에서 큰 차이(差異)가 없었다. Thiocarbamate계(系)의 esprocarb은 동계(同系)의 molinate에 비하여 피속(屬)에 대한 보다 강한 활성(活性)을 보였으며, 두 약제(藥劑) 모두 유효성분(有效成分) 함량(含量)이 높은 7G 제형(劑型)이 5G 제형(劑型)에 비하여 높은 활성(活性)을 보였다. 피 속간(屬間) 제초제(除草劑)에 대한 감수성(感受性) 차이(差異)는 종자(種子)크기에 따른 차이(差異)와는 關聯이 없지만, 종자(種子)크기는 초기(初期) 생육(生育) 단계(段階)에 영향(影響)을 미치며 이 초기(初期) 생육(生育) 단계(段階)즉 처리(處理) 당시(當時)의 엽기(葉期)에 따라 감수성(感受性) 차이(差異)를 나타낸다.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.651-656
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• 2012

Cationic immunoliposomes were prepared by conjugation of Fab' fragments of the recombinant humanized monoclonal antibody (HuCC49) against tumor-associated glycoprotein (TAG)-72 to sterically unilamella liposomes. The cationic immunoliposomes are composed of cationic lipid (O,O'-dimyristyl-N-lysyl aspartate, DMKD), cholesterol, and 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[maleimide(polyethyleneglycol)$_{2000}$] (DPPE-PEG-maleimide) with a molar ratio of 0.5:0.47:0.03. Plasmid DNA was effectively condensed by addition of transferrin (Tf) during the formation of anti-TAG-72 PEG-immunolipoplexes (PILPs). These anti-TAG-72 PILPs were able to adhere to the surface of TAG-72-overexepressing LS174T human colon cancer cells more effectively than conventional liposomes, thereby facilitating gene delivery in vitro. Furthermore, intravenous administration of the anti-TAG-72 PILPs into the tumor-carrying mice exhibited efficient localization of the reporter gene in the tumor tissues.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.181-181
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• 1999

Self-assembled monolayers(SAMs) of alkanethiol have been formed on the Cu(111) surfaces in vacuum. The thermal behavior of octanethiol-based SAMs on the Cu(111) surface have been examined in ultrahigh vacuum. Using X-ray photoelectron spectroscopy (XPS), it is found that the monolayers are stable up to about 500K in vacuum. Decomposition is signaled by a decrease in the intensity of C ls peak, accompanied by an increase of the intensity of the Cu 2p peak. However, the intensity of the S 2p peak doesn't change much as a function of annealing temperature. Thermal the decomposition mass spectra show that n-alkene is the predominant species desorbing from the surface in the 500-600K temperature range. The totality of these data leads to the conclusion that the monolayers decompose through the S-C bond cleavage by hydrogen elimination reaction, resulting in the desorption of hydrocarbon moiety as n-alkene. Following this initial decomposition step, Cu2S layers are observed on the surface. For comparison, attempts were also made to examine the thermal behavior of octanethiol-based SAMs on the Cu(111) surface in air. It has been shown that the SAMs on the Cu(111) surfaces begin to desorb with the oxidation of the thiolate to sulfonate at 400K. Upon annealing to 450K, the monolayer has almost completely desorbed as indicated by the virtual disappearance of the S 2p peak.

• Steel and Composite Structures
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• 제23권2호
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• pp.153-160
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• 2017

It is extremely important to be aware of the ballistic performances of engineering materials in order to be able to choose the lightest armor providing full ballistic protection in civil and military applications. Therefore, ballistic tests are an important part of armor design process. In this study, ballistic performance of plates made of carbon steel and cold worked tool steel against 7.62 mm AP (armor-piercing) bullets was examined experimentally and numerically in accordance with NIJ standards. Samples in different sizes were prepared to demonstrate the effect of target thickness on ballistic performance. Some of these samples were coated with titanium nitride using physical vapor deposition (PVD) method. After examining all successful and unsuccessful samples at macro and micro levels, factors affecting ballistic performance were determined. Explicit non-linear analyses were made using Ls-Dyna software in order to confirm physical ballistic test results. It was observed that the ballistic features of steel plates used in simulations comply with actual physical test results.

• 대한화학회지
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• 제32권3호
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• pp.195-202
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• 1988

Acetonitrile 용액중에서 3-phenyl-4-nitrosydnone의 전기화학전 환원을 direct current, differential pulse polarography, cyclic voltammetry 그리고 controlled potential coulometry 방법으로 연구하였다. Phenyl-N 단일 결합의 분리 이전에 nitro 기능기의 비가역적 전자 전달-화학반응(EC)기구의 진행으로 다전자 이동에 의한 amino(또한 hydroxylamino)기를 형성하고, 높은 음 전위 영역에서 2,3 비가역성 환원파의 일전자전달-화학반응에 의한 phenyl hydrazine을 생성하였다. 음극 반파 전위들은 cetyltrimethyl ammonium bromide의 억제 효과에 의해 음의 값으로 이동하였고 한편, sodium lauryl sulfate micelle은 높은 음전위 영역에서 제 2,3 환원파의 가역성산화 peaks를 보였다.