• 제목/요약/키워드: Central band

검색결과 257건 처리시간 0.023초

Reverberation Mapping of Nearby AGN with Medium-band and LSGT

  • Kim, Joonho;Im, Myungshin;Choi, Changsu;Hwang, Sungyong
    • 천문학회보
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    • 제45권1호
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    • pp.34.2-34.2
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    • 2020
  • Reverberation mapping is one of the best ways to investigate the physical mechanism of broad-line regions around central supermassive black holes of active galactic nuclei (AGNs). It is usually used to estimate the masses of supermassive black holes. Although spectroscopic reverberation mapping has used to study dozens of AGN, spectroscopic monitoring campaign of large sample is expansive. Here, we present results of photometric reverberation mapping with medium-band photometry. We monitored five nearby AGN which were already studied with H-alpha emission line. Observation has been performed for ~3 months with ~3 days cadence using three medium-band filters installed in LSGT (Lee Sang Gak Telescope; 0.43m). We found 0.01-0.08 magnitude variations from differential photometry. Also time-lags between continuum light-curves and H-alpha emission line light-curves are found using JAVELIN software. The result shows that our study and previous studies are consistent within uncertainty range. In the near future, medium-band photometric reverberation mapping seems useful to study large AGN samples. We will present preliminary result of following study that report new time lag measurement of six AGNs in the similar way.

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초단파 레이다의 부엽 차단 기능에 대한 설계 및 구현에 대한 연구 (A Study on the Design and Implement of The Function of the Sidelobe Blanking of VHF Radar)

  • 김기중
    • 한국전자통신학회논문지
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    • 제15권4호
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    • pp.637-642
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    • 2020
  • 본 연구는 S대역 또는 X대역 레이다 보다 빔폭이 상대적으로 큰 저주파 대역을 사용하는 초단파 레이다의 SLB/BLB 설계 및 구현에 대한 연구이다. 초단파 대역의 안테나는 빔폭이 상대적으로 크기 때문에 부엽에서 반사된 표적 신호를 처리하지 않으면 주엽 신호에서 들어온 것으로 인식하여 레이다의 탐지 오경보율이 증가한다. 부엽 차단 방법은 배열 안테나의 중앙쪽 복사소자를 사용하여 배열안테나 전면부의 부엽 신호를 차단하고, 뒤쪽에서 들어오는 신호는 BLB 수신안테나 조립체를 통해 차단시킨다. 레이다 구현을 완료하여 모의 신호 발생장치를 활용한 시스템 단위의 부엽 신호 차단에 대한 시험을 통하여 SLB/BLB 신호가 제거되는 것을 시험을 통하여 확인하였다. 본 연구를 통하여 향후 안테나 크기 및 빔폭이 큰 저주파 대역 레이다용 배열안테나의 부엽 차단 기술 구현에 활용할 예정이다.

중심성 폐암 발견에 있어 협대역 내시경의 임상적 유용성 (Clinical Benefits of Narrow Band Imaging Bronchoscopy in Central Lung Cancer)

  • 박진경;조영선;장세진;박영수;최창민
    • Tuberculosis and Respiratory Diseases
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    • 제68권1호
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    • pp.16-21
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    • 2010
  • Background: Lung cancer is usually diagnosed at an advanced stage, resulting in a poor prognosis. The detection of these lesions at an earlier stage would be a clear benefit to patients. However, it is extremely difficult to detect carcinomatous lesions in the bronchial mucosal sites during a routine bronchoscopy. Methods: This study employed a novel optical technique, known as narrowband imaging (NBI), which allows noninvasive visualization of the microvascular structure of an organ's surface using reflected light. Results: Narrow band imaging was performed on 10 patients who were radiologically suspicious or had a high risk of lung cancer. The median age of the patients was 57.5 years (range, 44~81 years), and 80% of the patients were male. All lesions showed a microvascular proliferation pattern (dotted, tortuous and abruptly ending vessel) on the magnified NBI. Two lesions were confirmed histologically to be adenocarcinoma and the remaining lesions were squamous cell carcinomas. Two lesions were confirmed histologically to be a carcinoma in situ. Conclusion: NBI is a promising and potentially powerful tool for identifying carcinomas at an earlier stage or a central lesion during a routine bronchoscopy examination.

가두리 양식장 주변의 수중환경소음과 생물소음의 특성에 관한 연구 (A Study on the Characteristics of the Underwater Ambient Noise and Biological Noise in Fish Farm Cages)

  • 박태건
    • 수산해양기술연구
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    • 제35권1호
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    • pp.41-49
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    • 1999
  • This paper describes to analyze the underwater ambient noise and biological noise of cultivating fishes in the fish farm cages at the seawater Tongyong-kun, KyongNam and lake of Chungju, Chech'on, ChungBuk from 10 to 19 Oct. 1997, in order to find out the characteristics of these noises. The results obtained were as follows; (1) The ambient noise around the fish farm cages at lake of Chungju was 10~200Hz frequency range, 70~105dB spectrum level. The central frequency was 50~70Hz, changing of ambient noise was getting bigger than 10~200Hz in 200Hz~2kKz frequency by wind, water current. (2) The frequency of noise source around the fish farm cage at the seawater of Tongyong-kun was 20~200Hz, spectrum level was 80~100dB while feed factory was working around the fish farm cage. When feed factory did not work, noise source was 10~600Hz frequency range, 70~90dB spectrum level. It was 10dB less than that of while feed factory was working, and then the central frequency was 70Hz. (3) The vessel noise of excursion ship had changed largely at 100dB spectrum level in 10~500Hz frequency band, and the fishing boat had 20Hz~2kHz frequency range. (4) The biological noise in the fish farm cage at lake of Chungju, which was feeding of Cyprinus carpio, 2was 10~30Hz frequency, 70~104dB spectrum level. The central frequency was 75Hz. The biological noises in the fish farm cage at the seawater of Tongyong-kun, which were feeding and swimming noise, had very different spectrum pattern by species, and the frequency band was 10~800Hz.

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IMPROVING EMISSIVITY ESTIMATION IN RETRIEVING LAND SURFACE TEMPERATURE WITH MODIS DATA

  • Lin, Tang-Huang;Liu, Gin-Rong;Tsai, Fuan;Hsu, Ming-Chang
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.337-340
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    • 2007
  • Many researches conducted to investigate the relationship between surface emissivity and surface temperature in the past two decades and pointed out that the emissivity play a key role in applying remote sensing data to retrieve surface temperature. The task of surface temperature estimation is so important in many research fields, such as earth energy budgets, evapotranspiration, drought, global change and heat island effect. Therefore, it is indispensable to develop an effective and accurate technique to estimate the emissivity for accurate surface temperature estimations. This study developed an improved emissivity estimation technique for the use of surface temperature retrievals with MODIS data. The result of applying this improved technique using Band 31 of MODIS shows that the accuracy of estimated surface temperatures will be improved. This study also uses MODIS data observed in 2005 to establish the relationship between the surface emissivity correction factor and NDVI. Through the use of these correction factors, the land surface temperature can be retrieved more accurate with MODIS data.

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각초 수분이 궐련의 끝빠짐에 미치는 영향 (Effects of the Moisture Contents of Cut Tobaccos on Loose End of Cigarettes)

  • 양범호;정한주;안대진;김용옥
    • 한국연초학회지
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    • 제27권2호
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    • pp.201-206
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    • 2005
  • In this work, we studied the effects of the moisture contents of cut tobacco on loose end of cigarettes. The loose end of the cigarette groups decreased with the increase of moisture contents of the cut tobacco and especially the loose end of A and C groups decreased to $31\%\;and\;52\%$ with the increase of $1\%$ moisture contents. $A-13.5\%\;and\;B-14.0\%\;and\; C-14.0\%$ moisture samples showed the increase of the weight ratio of cut tobacco over 1.4mm cut length but the decrease under 1.4mm cut length. We concluded that the main reasons were regarded to reduction of small fragment tobaccos caused by increase of moisture contents and exception of air-suction transport of tobaccos to cigarette making machine. In spite of the moisture increase of cut tobaccos under fixed EPD(encapsulated pressure drop), the hardness of Band C sample groups were maintained constantly except A group. This result means that under fixed EPD, the weight of cut tobacco in cigarette rods increases to compensate the reduction of pressure drop by moisture increase of cut tobaccos.

경남지역 양돈장의 돼지증식성회장염 감염률에 대한 연구 (Survey of porcine proliferative enteritis for the pig farms in Gyeongnam district)

  • 박동엽;박애라;정은희;배재형;이국천;황보원;이민권
    • 한국동물위생학회지
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    • 제32권4호
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    • pp.361-368
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    • 2009
  • Porcine proliferative enteritis (PPE) is a transmissible gastroenteric disease caused by Lawsonia intracellularis. Clinically, PPE causes hemorrhagic diarrhea and sometimes death in growing pigs, but when the disease progresses to a chronic phase, the infected pig no longer displays significant symptoms. The purpose of the present studies were carried out to determine L. intracellularis in the pig farms and slaughter house, in Gyeongnam area. A survey of proliferative enteritis in pig was conducted using polymerase chain reaction (PCR) testing method, total 1,495 samples. PCR products showed a specific band at the 210bp, 329bp in the specimens of feces and mucosal scraping. Of 420 fecal specimens, 113 (26.9%) were identified as positive to PPE. Of 1,075 mucosal scraping specimens, 109 (10.1%) were identified as positive to PPE. Of total 1,495 specimens, 222 (14.8%) were identified as positive to PPE.

2.4/5 GHz 무선 LAN 액세스 포민트용 이중 공진 판형 안테나 설계 및 구현 (Design and Implementation of 2.4/5 GHz Dual-Band Plate Type Antenna for Access Point of Wireless LAN)

  • 이원규;손지명;한준희;양운근
    • 한국전자파학회논문지
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    • 제17권5호
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    • pp.401-407
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    • 2006
  • 본 논문에서는 2.4/5 GHz 이중 대역의 무선 LAN(Local Area Network) 액세스 포인트용으로 크기가 작고 가벼운 이중 공진 안테나를 제안한다. 무선 LAN용 안테나는 전방향성의 방사 패턴 특성을 보여야 한다. 먼저, 제안된 이중 공진 안테나는 전방향성의 방사 패턴을 얻기 위하여 중심에 직교 역삼각형 소자와 네 개의 공진 소자를 사방으로 위치시켰다. 또한, 중심에 직교 역삼각형 소자를 사용한 구조에서 제작이 용이하고 크기가 작은 안테나를 구성하기 위하여 중심 소자를 판형으로 변경하였다. 제안된 이중 공진 관형 안테나의 측정 결과 사용 주파수 대역에서 -12.8 dB 이하의 특성을 보였다. 이득 측정 결과 2.44 GHz에서 3.17 dBi, 5.77 GHz에서 5.38 dBi의 최대 이득을 나타내었으며 전방향성의 방사 패턴 특성을 보였다. 구현된 안테나는 무선 LAN의 액세스 포인트에 적용 가능한 성능을 나타내었다.

국내 감자바이러스 Y (PVY) 저항성 육성 계통에서 분리한 PVY Mutant의 특성 (Characteristics of Potato Virus Y (PVY) Mutant Isolated from PVY Resistance Breeding Line in Korea)

  • 김재현;금완수;이신호;김정수;전용호;정석훈;정열영;박용학
    • 한국연초학회지
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    • 제28권2호
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    • pp.100-110
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    • 2006
  • A mutant of Potato vims Y (PVY) was occurred in PVY resistance flue-cured tobacco breeding line KF0402 $(TC1146{\times}KF117)$ showing vein necrosis at Suwon in Korea. This isolate, PVY-SWM, was differentiated from other PVY based on biological properties and nucleotide sequence analyses of coat protein gene. PVY-SWM caused typical symptoms on 21 indicator plants as compared to the PVY-TOJC37. Remarkably, the PVY-SWM induced distinctly different symptom of systemic vein necrosis on tobacco cultivars V.SCR, PBD6, TN86, TN90, Virgin A Mutant (VAM), Wislica, NC744, KB108 and KB111, which were reported to have the recessive potyvirus resistance gene va. In RT-PCR assays with specific primers for detection of PVY, a single band of about 800bp in length was produced. The amplified DNA was cloned and the nucleotide sequence was determined. The coat protein gene of PVY-SWM showed 88.4%-99.0% and 92.5%-98.5% identities to the 12 different PVY isolates of Genbank Database at the nucleotide and amino acidi respectively. Multiple alignments as well as cluster dendrograms of PVY-SWM isolate revealed close phylogenetic relationship to the $PVY^{NTN}$ subgroup.

$\alpha$- and $\beta$-Amylase Isozyme Expresser Native Proteins in Tropical Silkworm Bombyx mori L.

  • Chattopadhyay, G.K.;Verma, A.K.;Sengupta, A.K.;Das, S.K.;Urs, S.Raje
    • International Journal of Industrial Entomology and Biomaterials
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    • 제8권2호
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    • pp.189-194
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    • 2004
  • Amylase isozyme based three multivoltine viz., N+p, Np, N+ $p^{cho}$ and two bivoltine-D6+p, D6p syngenic lines (Syn. L) were developed from germplasm (GP) stocks Nistari (N) and D6 respectively. haemolymph isozyme pattern at pH 7.0 and 8.5 depicted a total 11 number (Am $y_{1 to 6}$ at pH 7.0 and Am $y^{l to 5}$ at pH 8.5) of native proteins (NP) of various sizes are amylase isozyme expressers. Among eleven NPs, two NPs of 770 kDa (Am $y^{6}$ at pH 7.0) and 376 kDa (Am $y^3$ at pH 8.5) are $\alpha$-amylase expressers and remaining NPs of 370, 364, 350, 329 and 274 kDa at pH 7.0 and 206, 292, 416, 725 kDa at pH 8.5 are $\beta$-amylase expressers. Accordingly, digestive juice amylase isozyme pattern at aforesaid pH also depicted a total number of 10 NPs (Am $y^{1 to 5}$) at each pH 7.0 and 8.5 are amylase expressers of which NP of 387 kDa (Am $y^4$ at pH 7.0) and 780 kDa (Am $y^{5}$ at pH 8.5) are a-amylase expresser. Remaining NPs of 338,297 & 216 kDa at pH 7.0 and 370, 341, 329 &302 kDa at pH 8.5 are $\beta$-amylase expresser. Recurrent backcross lines (RBL) viz., N+pRBL and NpRBL were developed through introgression of high shell weight character (a multigenic trait) to be used further for congenic line (Con. L) development and to understand any association with introgressed character. Isozyme pattern in haemolymph of RBLs depicted only one $\alpha$-amylase of 770 kDa at pH 7.0 and 376 kDa at pH 8.0 with three and four respective $\beta$-amylase bands but in bivoltine lines numbers of $\beta$-amylase bands vary between 1 to 2 at aforesaid pH. Variability was also observed in digestive juice of multivolitine and its RBLs but bivoltine lines express null activity at both pH except appearance of one very week $\alpha$-amylase band D6+p at pH 8.5. Overall study suggests that not a single NP at both pH is common for expression of any band of amylase isozyme i.e., a totally different set of proteins are the amylase isozyme expresser at specific pH and no molecular factor of amylase is associated in developed RBLs which showed improvement on survival, single cocoon shell weight (SCSW) and single filament length over receptor parents.s.s.s.