• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1545-1546
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• 2011

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.11a
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• pp.155-158
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• 2009

원활한 방송 서비스를 제공하고 손쉬운 방송망 구축을 위해서 가장 중요한 것은 서비스 하 고자 하는 주파수 대역과 환경에 맞는 전파 모델을 선택하는 것이다. 적절한 전파 모델을 선택하여 수신 전계 강도를 정확하게 예상함으로써 효율적인 방송망을 설계할 수 있는 것이다. 방송망 주파수 대역에서 전파 분석 시 널리 이용되고 있는 모델은 ITU-R 권고안 P.1546 모델이다. 이 모델은 기존의 Okumura 나 Hata 모델처럼 측정을 기반으로 하여, 송신단 높이, 수신단 높이, 주파수, 거리, 시간율, 공간율 들을 고려하여 완성한 점대 영역 경로 손실 예측 모델이다. 측정을 기반으로 완성된 경로 손실 모델이기 때문에 실제 환경에 적용하기 위해서는 전계강도 예측 지역의 수신 환경 특성을 반영한 보정값을 더해줘야 한다. 이러한 문제를 해결하기 위해서 ITU-R 연구 3그룹은 지형 프로파일에 기반한 새로운 모델들을 개발하였다. 송, 수신단 사이의 지형 데이터가 고도화되면서 좀 더 정밀한 송, 수신단 사이의 지형 프로파일을 추출해 낼 수 있으며 이는 정확한 전계강도 예측을 가능하게 하였다. 이에 연구 3그룹은 고도화된 디지털 지형 데이터를 이용하여 자유 공간에서 경로 손실, 지형에 의한 회절 손실, 대류권 산란 손실 그리고 ducting 현상을 반영하여 전계강도를 산출해 내는 ITU-R P.1812 모델을 제안하였다. 본 논문에서 우리는 ITU-R 권고안 P.1812를 분석 구현하고 기존의 대표 모델인 P.1546 모델과의 비교 분석을 시도하였다.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.1
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• pp.40-47
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• 2013

By virtue of Rec. ITU-R P.1546 and geography information system, interference analysis for the fixed wireless system and radar has been presented based upon the frequency-distance rules with minimum coupling loss, and a comprehensive methodology for assessing interoperability between systems was examined in terms of received signal, protection ratio, frequency dependent rejection. Also to find the antenna gain from a discrimination angle, a useful S-I plane was introduced based on signal and interference vectors derived from the real map with geographic information. To show some computational results, geography information on the map was taken for the given area, and field strength and path profile were illustrated for the radar and fixed wireless system operating at 2.7 GHz, for convenience. In addition the interference effect of receiver was also checked as a function of radar beam direction including protection ratio and frequency dependent rejection. The developed interference analysis can be actually applied to evaluate interoperability for wireless systems in the VHF and UHF bands.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.116-124
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• 2012

Identification was performed in March 2008 for the 76 Enterococcus strains isolated from the Han-river, which is used as water supply for Seoul citizens. The antibiotic susceptibility, antibiotic resistant structural analysis, trans-conjugation, pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) were also carried out for the isolated strains. Among the isolated strains, 25 strains were E. casseliflavus, 4 strains were E. faecalis and 1 strain was E. hirae. Investigation of antibiotic susceptibility indicated that 15 strains demonstrated tolerance against vancomycin, and that 11 strains of E. faecium and 4 strains of E. casseliflavus were VRE. The vanA gene detection of the VRE strains revealed that 6 E. faecium strains were vancomycin-resistant Enterococcus faecium (VREF) possessing vanA. Analyses of transposon Tn1546 structure containing vanA demonstrated that Km36 and Km37 belonged to Tn1 type, Km20 and Km38 was Tn2 type, and Km39 and Km40 was Tn3 type. PFGE disclosed that among the 6 VREF strains, Km36 and Km37 exhibited equivalent subtype, while the rest 4 strains showed subtypes different to each other. MLST for the 6 VREF strains disclosed that 3 strains were ST78, while the rest 3 strains were ST18, ST192 and ST230, respectively. All these clonal complexes were derived from CC17 which has been isolated from clinical sources. 4 strains belonged to CC78, while the rest 2 strains were CC18 and CC192, respectively.

• The Science & Technology
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• v.9 no.8 s.87
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• pp.42-43
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• 1976

인류의 과학기술이 천체 외계에 까지 미치게 되었다. 천체역학의 역사적 배경을 살펴보면 1600년초기 Johannes Kepler(독1571~1630)가 그의 스승 Tycho Brahe(덴마크 1546~1601)의 천체 위치관측(특히 화성)자료를 분석하면서 천체역학의 세 법칙을 발견함에서 비롯되었다. 그후 거의 3세기반이 지난 20세기 후반에 와서 천체역학 혹은 궤도역학을 이용하여 인공위성을 띄우게 되는 실용기를 맞이한 것이다. 다른 공학을 보게되면 이론이 정립되고 그것이 하나의 기계화로서 실용화 되는 것이 수년내에 여러사람에게 혜택을 주게되지만 천문학의 일분야인 천체역학은 인공위성을 띄워서 과학연구를 비롯하여, 통신, 기상예보, 자원개발, 농사수확예보등 인류전체에게 혜택을 주기까지 무려 3세기반이 걸린 것이다.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1543-1546
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• 1987

In this paper, we give an overview of harmonious graphs and graceful graphs, identify the simply sequential and survey graceful graphs of wheels. Finally, we describe B-valuation of wheels which Can be used in graceful numbering.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1546-1549
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• 2006

We have developed $EPLaR^{TM}$, a new way of making flexible electrophoretic displays. The TFTs have the same good performance, reliability and mature manufacturing processes as TFTs used in LCD monitors and LCD-TVs. We are working with partners to show that plastic displays can be made in existing TFT-LCD factories alongside glass LCDS. In this talk we describe the EPLaR process and show results for TFT arrays on plastic made in a factory by standard ${\alpha}$-Si TFT processing.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1546-1552
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• 2004

Railway schedule is periodically modified so that it could yield more profit by means of adjusting the schedule to demand. Most of related works are applicable under the given demand, but did not deal with dynamic relation between demand and schedule. To our knowledge, the methodology considering the relation is only the profitability evaluation model developed by SNCF. Our study suggests how to adjust the schedule to demand and therefore obtain more benefits using the profitability evaluation model.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1546-1550
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• 2006

The purpose of this study was to assess the genetic variation and establish the relationship amongst breeds and strains using 15 chicken specific microsatellite markers. A total of 285 unrelated DNA samples from four Korean native chicken strains (Black strain of Korean native chicken; KL, Red Brown strain of Korean native chicken; KR, Ogol strain of Korean native chicken; KS and Yellow Brown strain of Korean native chicken; KY) and three introduced chicken breeds (F strain of White Leghorn; LF, K strain of White Leghorn; LK, Rhode Island Red; RC and Cornish; CN) were genotyped to estimate within and between breed genetic diversity indices. All the loci analyzed in 15 microsatellite markers showed a polymorphic pattern and the number of alleles ranged from 5 to 14. The polymorphism information content (PIC) of UMA1019 was the highest (0.872) and that of ADL0234 was the lowest (0.562). The expected total heterozygosity (He) within breed and mean number of observed alleles ranged from 0.540 (LF) to 0.689 (KY), and from 3.47 (LK) to 6.07 (KR), respectively. The genetic variation of KR and KY were the highest and the lowest within Korean native strains, respectively. The genetic distance results showed that Korean native chicken strains were separated with the three introduced chicken breeds clustered into another group. The lowest distance (0.149) was observed between the KR and KL breeds and the highest distance (0.855) between the KR and LK breeds. The microsatellite polymorphism data were shown to be useful for assessing the genetic relationship between Korean native strains and other foreign breeds.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.10
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• pp.1546-1550
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• 2007

This study aimed to provide basic information as the foundation for further studies on the assessment of velvet antler quality by investigating the changes in fatty acid, vitamin A and E, minerals and GAGs contents by development stage of antler in spotted deer (Cervus nippon). Twelve stags (aged 4 to 5 years) were divided into two groups and velvet antler harvested 40 days (FDG) and 60 days (SDG) after casting of the buttons from the previous set. Total saturated fatty acid was lower in FDG than SDG (p<0.05). Total monounsaturated fatty acid, conjugated linoleic acid (p<0.05), polyunsaturated fatty acid and ${\omega}$3 fatty acid were higher in FDG than SDG. The vitamin A content of FDG was higher than that of SDG, but the vitamin E content of FDG was lower than that of SDG (p<0.05). SDG had significantly higher calcium and phosphate content than FDG (p<0.05). The magnesium content showed a similar trend to the contents of calcium and phosphate, but there was no significant difference between SDG and FDG. Uronic acid content was higher in FDG than SDG but there was no significant difference. The contents of GAGs and sialic acid were significantly higher (p<0.05) in FDG than SDG. These results indicated that the longer stage of antler development had lower content of activating components and this lead to a decrease of antler quality.