• Annual Conference of KIPS
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• 2016.10a
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• pp.181-183
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• 2016

적지종심작전 부대는 적 후방에서 활동함에 따라 원거리 지휘통신을 위해 AM 무전기를 사용하게 된다. 하지만 AM 무전기의 데이터 전송속도는 매우 낮기 때문에 이를 적지종심작전 부대에서 활용되는 군 모바일 단말기는 AM 무전기 특성에 맞는 데이터 통신에 대한 최적화 설계가 적용되어야 되다. 본 연구에서는 AM 무전기 특성인 응답송신대기시간, 송신 패킷 간격을 고려한 ACK 송신 대기시간, 재전송 시간 조정, 일정 시간 후 자동 전송되는 데이터 제한 등의 설계를 적용, 실 지형에서의 시험을 통해 데이터 전송의 최적화 설계가 필요함을 제시하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.1
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• pp.116-126
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• 1997

As the digital system with high sampling rates is required to process numerous data, it is difficult to realize the real time processing for this system. By using the nonlinear energy tracking signal operator, in this paper four kinds of AM/FM demodulators are proposed and designed by the undersampling scheme of decreasing the sampling rate. Particularly, the undersampling frequency and 3dB bandwidth are controllable of these systems and their conditions are respectively. Through the analysis of the designed detectors, useful results are obtained in respect to characteristics and errors.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.181-184
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• 2003

The Four-Ball Tester has been widely used as a tool to charaterize lubricity for long time. In order to understand more acurate properties of lubricants, more test methods have been developed. Among the test methods, SRV test method was compared to Four-Ball Tester in this paper.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.149-151
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• 2003

This report describes the adhesibility of the polyurea greases. Generally, Polyurea greases were divided into three classes, aliphatic, alicyclic, and aromatic, according to the differences of the terminal alkyl group. The adhesion properties of polyurea greases were tested with Adhesion Tester by In-house method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.5
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• pp.711-718
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• 1999

Some of modern communication systems make use of broadband digital modulation with 5 MHz and 10 MHz. In the broadband communication systems, the nonlinear properties of power amplifier have a great effect on all systems. This paper analyzed the ACPR characteristics of WLL reverse link power amplifier with the varying AM and PM nonlinearities and suggests the required backoff from 1 dB compression point to satisfy the ACPR specifications. Also the comparions between the measured and the simulated characteristics are presrnted.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.841-846
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• 1995

대전지역 토양에서 추출한 흄산(TJHA)과 Am(III), Eu(III)의 착물형성에 대한 안정도상수를 추출용매 di-2-ethylhexyl phosphoric acid와 희석제 toluene을 사용하여 용매추출법으로 구하였다. 이온강도가 0.1M NaCIO$_4$에서 TJHA의 총 carboxylate capacity를 직접 전위차적정법으로 분석한 결과 3.757 meq/g이고, apparent pKa는 5.15 이었다. TJHA와 Am(III) 및 Eu(III)의 조건부 안정도상수의 log$\beta$1 값과 log$\beta$2 값을 흄산의 이온화도 함수로 구한 결과, Eu-TJHA은 0.1M NaClO$_4$일때 log $\beta$1=5.948$\alpha$ + (6.83 $\pm$ 0.3) 및 log $\beta$2 = 5.687$\alpha$ + (10.44 $\pm$ 0.4)이며, Am-TJHA은 log$\beta$$_1$= 4.004 $\alpha$ + (6.96 $\pm$ 0.2) 및 log$\beta$$_2$= 3.719 $\alpha$ + (11.71 $\pm$ 0.2)이었다.

• Mycobiology
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• v.30 no.1
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• pp.13-17
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• 2002

The genomic DNAs were extracted from roots of Glycine max and Sorghum bicolor, and compared with those from spores of two arbuscular mycorrhizal(AM) fungi, Glomus mosseae and Scutellospora heterogama. The partial small subunit(SSU) of ribosomal RNA genes were synthesized and amplified by polymerase chain reaction with the fungal specific primers, AM1 and NS31. By the recent molecular techniques, the presence of another AM fungal DNA were confirmed in the roots of two plants, and three sequences of rDNA fragments amplified were identified to be close to those of G. caledonium, G. fasiculatum and G. proliferum. The two AM fungi, both, were found to colonize at the cortical layers of plant roots collected in the fields, together.

• Bulletin of the Korean Chemical Society
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• v.23 no.4
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• pp.555-562
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• 2002

Isomers based on the RS and EZ geometrical isomerism of the neutral, deprotonated species of HMPAO and their complexes with zinc(Ⅱ) ion have been investigated by semiempirical AM1 optimization method. The Hartree-Fock energies on AM1 geometries o f HMPAO species were calculated with HF/6-31G* methods. Twenty-two isomers of the neutral and twenty isomers of the deprotonated species of HMPAO have been found. The presence of four EE-series isomers of both zinc(Ⅱ) complexes with the neutral and deprotonated HMPAO have been expected and the SREE typical isomer of both types of complexes is the most stable isomer. Energies of complexation of zinc(Ⅱ)/HMPAO isomers with AM1 geometries were calculated by HF/ 6-31G*method. Due to the complexations with zinc(Ⅱ), the structural reorganizations of some isomers of the neutral HMPAO have been occurred. The optimized geometrical parameters of the related conformations have been discussed in terms of their stabilities and existences.

• Archives of Pharmacal Research
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• v.16 no.3
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• pp.175-179
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• 1993

Gas chromoatography with flame ionization detector (FID) along with mass spectrometry (GC/MS) were used for the screening and quantification of methamphetamine (MA) and its major metabolite, amphetamine (AM0, in blood and urine in eleven fatal cases in which MA abuse was suspected. Postmortem blood MA varied from $0.5-30.2\;\mu{g/ml}$, while Am levels ranged from none detected (6 of 11 cases) to 4.8 .mu.g/ml. Additionally, distribution studies were performed in three of these cases in which tissue smaples were available for evaluation. Liver contained the highest ocncentration of MA among the tissu samples. In eight of the eleven cases, when no other direct cause of death was evident (i.e. 3 cases of traumatic dath0, either no blood AM was found or the ratio of MA/AM was 3.4 or greater. These data are consistent with acute MA use followed by death due to acute drug intoxication or by the occurrence of hypersensitivity and reverse seen in cases of chronic drug abuse.

• YAKHAK HOEJI
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• v.37 no.4
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• pp.356-361
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• 1993

A sensitive method for the determination of methamphetamine(MA) and amphetamine(AM) in hair was developed by gas chromatography/mass spectrometry using stable isotope-labeled internal standards, amphetamine-d$_{5}$ and methamphetamine-d$_{5}$. Hair sample was washed with MeOH, incubated with MeOH(I% HCI) overnight at $37^{\circ}C$ while stirring and extracted using solid phase extraction column on a vacuum manifold. The extract obtained was pentafluoropropionated, and applied to GC/MS. The calibration curves of MA and AM were linear from 2.5 to 250 ng (r>0.99 for both). The limit of detection was 0.1 ng/mg in hair and cut-off level was set at 0.25 ng/mg for both. Hair samples of 27 MA abusers showed positive results in the range 0.7 to 106.8 ng/mg. AM, its metabolite, was detected in 20 out of 27 samples. The ratio of MA versus AM was 4.6~38.3 in specimens. Hair analysis for methamphetamine by GC/MS is an effective method for identifying long-term drug abusers.