• 제목/요약/키워드: B4 Mount

검색결과 45건 처리시간 0.025초

최정산 위성추적소의 천체관측 환경에 관한 조사 연구: I. SEEING 및 야천광 관측과 위성추적소의 활용 방안 (A STUDY ON THE ASTRONOMICAL OBSERVATIONAL ENVIRONMENTS AT THE CHOEJUNG-SAN GEODSS SITE: I. SEEING AND NIGHT SKY BRIGHTNESS MEASUREMENTS AND UTILIZING PLAN FOR THE GEODSS SITE)

  • 강용희;윤태석;박병곤;이기원;최영준;최은우
    • 천문학논총
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    • 제11권1호
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    • pp.177-196
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    • 1996
  • We have investigated the astronomical observational environments at the Choejung-san GEODSS site which is located at the south of Taegu, Korea. As a part of the investigation, seeing and night sky brightness were measured outside nearby the GEODSS site using the Celestron 8-inch portable reflector with $192{\times}165$ pixels Lynxx CCD camera during the period of December 1994 to April 1996. The average seeing values of 4.8 arcsecond in B filter and 5.1 arcsecond in V filter were determined using the IRAF software. These values might be overestimated and would be reduced by at least 1 arc second in both filters if they were measured by more stable telescope system with solid mount and under a dome. We also compare the average seeing value at the GEODSS site with those at three other observatories, the Bohyunsan Optical Astronomy Observatory, the Sobaeksan Optical Astronomy Observatory, and the Seoul National University Observatory, for justification of the above guess. Unfortunately the night sky brightness measurement was not successful mainly due to the short exposure time. The utilizing plan of the GEOSS site is discussed based on the average seeing value, naked-eye sky brightness measurement, analysis of the existing thirty-year weather data and twenty-year urban planning of the metropolitan Taegu city for the year of 2016.

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공주 송산리 고분군(公州 宋山里 古墳群)에서의 물리탐사와 무령왕릉(武寧王陵)의 구조분석 (Geophysical Exploration of Songsalli Ancient Tombs and Analysis of King Muryeong's Tomb Structure, Gongju)

  • 오현덕
    • 헤리티지:역사와 과학
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    • 제46권4호
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    • pp.4-23
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    • 2013
  • 공주 송산리 고분군(公州 宋山里 古墳群)은 7기의 무덤으로 구성되어 있으며, 그 중 7호분인 무령왕릉(武寧王陵)은 1971년에 5호분과 6호분의 배수로 공사 중 발견된 전축분이다. 당시 발굴조사는 무덤의 입구와 현실 내부의 측량조사, 유물수습을 중심으로 이루어졌다. 봉토부 조사에서 호석의 일부 잔존상황과 석회혼합토층을 확인하였으나 봉토를 더 깊이 제거하여 전축분의 외형구조까지는 조사하지 않았다. 발굴조사 후 6호분과 7호분에서 벽돌 손상, 습기와 곰팡이로 인한 벽화 손상이 발견되었다. 그 원인을 규명하기 위해 공주대학교가 1996년부터 1997년까지 물리탐사를 포함하여 송산리 고분군에 대한 종합 정밀조사를 실시한 바 있다. 그 결과를 바탕으로 1999년에 보수공사가 이루어지고 문화재보존을 목적으로 5, 6, 7호분은 영구 보존 조치되어 현재 일반인의 출입을 금하고 있는 상태이다. 이번 연구의 목적은 송산리 고분군 5, 6, 7호분의 지표 위에서 3차원 전기비저항 탐사, GPR 탐사를 실시하여 보수공사 이후의 지하의 상태를 파악하고 무령왕릉의 내부에서 GPR 탐사를 실시하여 전축분의 벽체의 두께와 외형적 구조를 파악하는 데 있다. 지표에서의 탐사결과, 3기의 고분 주변의 토양은 $5{\sim}90{\Omega}m$ 의 낮은 전기비저항 값을 나타내고 있어 토양이 갖는 함수율이 보수공사 이전처럼 여전히 높은 것으로 나타났다. 또한 GPR 탐사결과, 무령왕릉 현실의 벽체 축조방식은 약 35cm 길이의 벽전을 길이방향으로 두 장 잇댄(2B 벽돌쌓기) 약 70cm 두께임을 알 수 있었다. 반면 연도부는 약 80cm 두께로 측정되어 현실의 벽체와 같은 두 겹 구조에 눈썹아치가 복합된 구조로 추정된다. 그리고 천장의 외형은 내부의 모양과 같은 아치 구조임을 탐사결과를 통하여 추정할 수 있었다.

폐와 중추신경계를 침범한 효모균증(Cryptococcosis) 1예 (A Case of Cryptococcosis involving Lung and CNS without Underlying Disease)

  • 이민수;박상선;고영일;장안수;임성철;양주열;박형관;나현주;김영철;최인선;박경옥
    • Tuberculosis and Respiratory Diseases
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    • 제42권4호
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    • pp.618-623
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    • 1995
  • 저자들은 내원 3개월 전부터 발생한 두통을 주소로 내원하여 검사결과 폐와 중추신경계를 동시에 침범한 효모균증으로 진단된 56세 여자환자에서 amphotericin B로 6주간 치료한 후 fluconazole 200mg/day로 전환하여 3개월간 경구 투여하여, 증상 및 흉부 방사선 소견의 호전과 함께 뇌척수액 추적 검사상 호전되고 두부 전산화 단층촬영상 특이 소견은 발견하지 못한 1례를 경험하였기에 문헌고찰과 함께 이에 보고한다.

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LTCC 의사 유전체 공진기를 이용한 초소형 전압제어발진기 설계 (Design of a Ultra Miniaturized Voltage Tuned Oscillator Using LTCC Artificial Dielectric Reson)

  • 허윤성;오현석;정해창;염경환
    • 한국전자파학회논문지
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    • 제23권5호
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    • pp.613-623
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    • 2012
  • 본 논문에서는 LTCC(Low Temperature Co-fired Ceramics) 공정을 이용하여 다층 구조의 의사 유전체 공진기를 설계하고, 이를 HMIC(Hybrid Microwave Integrated Circuit) 형태의 증폭기, 위상천이기와 함께 폐루프를 구성하여 초소형 전압 제어 의사 유전체 공진기 발진기(Vt-ADRO: Voltage-tuned Artificial Dielectric Resonator Oscillator)를 제작하였다. 의사 유전체 공진기는 주기적인 도체 패턴과 적층을 통해 기존의 유전체 공진기보다 소형의 크기를 갖는 공진기이다. 의사 유전체 공진기의 형상은 기본 도체 패턴 원판형을 갖고 이것을 적층하는 구조를 선정하였으며, 공진기의 물리적 치수 및 적층 수에 따른 공진 특성을 분석하였다. 소형의 크기로 제작하기 위하여 LTCC 기판의 상부에 의사 유전체 공진기를 내장하고, 하부에 증폭기, 위상천이기를 집적하였다. 제작된 의사 유전체 공진기 발진기는 $13{\times}13{\times}3mm^3$로 초소형이며, SMT(Surface Mount Technology) 형태를 갖는다. 설계된 발진기는 설계 주파수에서 개루프 발진 조건을 만족하였으며, 폐루프 측정 결과, 발진 주파수는 조정 전압 0~5 V에서 2.025~2.108 GHz, 위상 잡음은 100 kHz offset에서 $-109{\pm}4$ dBc/Hz, 출력 전력은 $6.8{\pm}0.2$ dBm을 보이며, PFTN(Power Frequency Tuning Normalized) FOM(Figure Of Merit)은 -30.88 dB를 보인다.

LED 비디오월을 사용하는 방송환경에서 HD 카메라의 적정 초점거리 연구 (A Study on the Adequate HD Camera Focal Length in the Broadcasting Studio using LED Video Wall)

  • 최기창;권순철;이승현
    • 문화기술의 융합
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    • 제8권5호
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    • pp.713-721
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    • 2022
  • LED 비디오월을 방송 현장에서 사용하기 위해서는 몇 가지 알아두어야 할 사항이 있다. 첫째, 픽셀이 촘촘히 배열되어 있기 때문에 짧은 배열 주기로 인한 무아레 현상이 나타날 수 있고, 둘째, 픽셀 간의 거리(픽셀피치)가 촬영하는 카메라 이미지 센서에 기록될 수 있다. 무아레 현상이 발생하거나 픽셀피치가 관찰되게 되면 시청자의 입장에서는 불편함을 느끼게 된다. 무아레 현상은 카메라의 촬영거리나 각도를 조정하면서 감소시킬 수 있지만, 픽셀피치가 이미지 센서에 녹화되는 걸 방지하기 위해서는 LED 비디오월과 카메라와의 거리를 충분히 확보하거나, 거리가 확보된 상태에서도 픽셀피치가 녹화되지 않도록 방송 현장에서 사용되는 줌렌즈의 배율을 적절하게 변화시켜 운용해야 한다. 원하는 화각을 얻기 위해 배율을 변경시켜 초점거리를 변동시키게 되면 의도치 않게 픽셀피치가 녹화되는 결과를 초래할 수 있다. 본 논문에서는 비디오월과의 거리가 충분히 확보된 상태에서 줌렌즈의 배율을 변경하면서 픽셀피치가 관찰되지 않는 범위에 대해 알아보았다. LED 비디오월에 영상을 재생시켜 B4 마운트 줌렌즈를 장착한 HD 카메라와 서버를 사용해 LED 비디오월 상태를 녹화하였고, TV 화면으로 재생하여 픽셀피치가 관찰되는지 확인해 보았다.

트롤그물의 기본 성능에 관한 고찰 (Study on the basic efficiency of trawl net)

  • 오택윤;김영승;최석관;배재현;조삼광;박창두;안희춘;신종근;양원석;문대연
    • 수산해양기술연구
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    • 제42권3호
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    • pp.148-157
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    • 2006
  • A model experiment, simulation test using personal computer and real sea trial fishing were carried out to investigate the basic efficiency of bottom trawl net which can be used in the sea mount of North West Pacific, and experimental values were analyzed as the values of full-scale bottom trawl net. Hydrodynamic resistance for the full-scale trawl net according to the Koyama equation was 2.1 times higher than that of simulation and 2.4 times higher than that of model experiment at the average towing velocity. At the 3.5kt's of towing speed, net width of the full-scale trawl net was 2.5% smaller than that of simulation and 8.2% larger than that of model experiment. On the fishing experiment of the full-scale trawl net for the 3.5kt's of average towing speed, average net height of A group(same direction with external force) was 423.5% higher than that of model experiment and 457.1% higher than that of simulation and that of B group(opposite direction with external force) were 283.8% and 306.3% higher than in case of model experiment and Simulation respectively. Net mouth of the full-scale trawl net was 338.1-504.6% higher than those of model experiment and simulation in A group, and 525.2-745.3% higher in B group.

국내 냉동 및 냉방부문 온실가스 배출량 산정 - 2006 IPCC GL Tier 2b 적용 - (Estimation of Domestic Greenhouse Gas Emission of Refrigeration and Air Conditioning Sector adapting 2006 IPCC GL Tier 2b Method)

  • 신명환;유영숙;서경애;이수빈;임철수;이석조
    • 한국기후변화학회지
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    • 제3권2호
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    • pp.117-128
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    • 2012
  • 우리나라는 기후변화 대응과 경제성장의 선순환 구조를 정착하고, 온실가스 감축의무에 대한 국제사회의 요구와 압박에 효과적으로 대응하기 위해 많은 노력을 기울이고 있다. 특히 국제사회에 발표한 국가 온실가스 중기 감축목표(2020년 BAU 대비 30% 감축)의 이행을 위하여 부문별 업종별 온실가스 감축목표 설정 및 할당, 다(多)배출원에 대한 온실가스 에너지 목표관리제 적용 등 단계적인 온실가스 감축을 위한 정책을 추진 중에 있다. 이와 같은 제도의 성공적 정착과 시행을 위해서는 보다 정확하고 신뢰도 높은 부문별 온실가스 인벤토리가 필요하다. 특히 불소계 온실가스(HFCs, PFCs, $SF_6$)는 대표적 온실가스인 $CO_2$에 비교하여 GWP(global warming potentail)가 높아 지구온난화에 미치는 영향이 큼에도 불구하고, 우리나라에서는 아직까지 이에 대한 배출원 파악, 적용 가능한 활동자료 수집, 배출량 산정 등 체계적인 배출 통계 구축을 위한 연구가 부족한 실정이다. 따라서 본 연구에서는 불소계 온실가스 배출원 중 냉매(HFCs)를 사용하는 냉동 및 냉방부문을 중심으로 온실가스 배출량 산정방법론의 적용 타당성을 검토하였으며, 검토된 방법론을 이용하여 이동형 에어컨, 고정형 에어컨, 가정용 냉동장치, 상업용 냉동장치에 대한 온실가스 배출량을 산정하였다. 우선 방법론 측면에서 살펴보면, 냉동 및 냉방부문의 온실가스 배출량 산정에 있어 국가고 유배출계수 개발이나 산업부문의 활동 자료 통계 DB의 구축이 미비한 실정이므로 2006 IPCC 가이드라인의 Tier 2a(배출계수 접근법)보다는 Tier 2b(물질수지 접근법)가 적절하다고 판단된다. 2009년도 냉동과 냉방부문의 냉매사용에 따른 온실가스 배출량($CO_2eq.$) 산정 결과, 이동형 에어컨은 1,974,646 ton/year, 고정형 에어컨은 1,011,754 ton/year, 가정용 냉동장치는 4,396 ton/year, 상업용 냉동장치는 1,263 ton/year으로 총 2,992,037톤으로 산정되었다.

페르시아 파르티아[Parthia]왕조 남자복식 연구 (A Study on Men's Costumes of the Parthian Period in Persia)

  • 장영수
    • 복식
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    • 제56권4호
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    • pp.65-81
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    • 2006
  • This is the study on the costumes of Parthian Period in Persia which had powerful influences on the Occidental and Western cultures in B.C 3 to A.D 3. With different types of Parthian costumes in each period, this study shows what types of costumes people used to wear and how they were co-related with its surrounding cultures. The ancient costumes of Korea had something to do with the elements of the Northern part at that time. To make an intensive study of Korean ancient costumes, these Parthian costumes which are known to those of northern nomadic tribes are studied to provide basis elements for study between the Korean styles and the exotic styles. The basic forms of the Parthian styles were jackets and trousers. They consisted of three kinds of jackets such as those to be adjusted In the front, tunics and coats. As for trousers, they were divided into three types such as those with horizontal pleats, round-side pleats and vertical pleats. 1) The jacket to be adjusted in the front was long enough to reach the hip and fit the body reasonably tight, and its neckline was shaped into V-type. It was a very popular style among the people of high and low classes. 2) The tunics had narrow sleeves. It was a one-piece pattern which reached the knees. It was settled with a belt on the waist. Its neckline was shaped into the round but its slit was not cleat. Its styles were into tight-fit and drapery ones. 3) The coats were almost similar to the jacket to be adjusted in the front with short length, but they were entirely long and open. They appeared later than the short jackets and the people of high class seemed to wear these styles. 4) 1'rousers with horizontal pleats - They had almost horizontal pleats on them, and they were a little tight. They seemed to be the early style in the Parthian period. 5) Trousers with round side-pleats - With saggy side pleats on them, these trousers had round pleats like a drapery style. This pattern was also considered Hellenistic elements shown in the Parthian costumes. The trousers consisted of the underdrawers and the leggings (called salwar or shalwar), which is thought to emphasize its functionality for its wearer to mount a horse with more ease. 6) Trousers with vertical pleats - With straight vertical pleats on them, these trousers had some volumes and bias decorations in the middle of them. These styles were thought to be worn by the ruling class of the Parthia from early to late period.

Attributable Causes of Liver Cancer Mortality and Incidence in China

  • Fan, Jin-Hu;Wang, Jian-Bing;Jiang, Yong;Xiang, Wang;Liang, Hao;Wei, Wen-Qiang;Qiao, You-Lin;Boffetta, Paolo
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권12호
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    • pp.7251-7256
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    • 2013
  • Objectives: To estimate the proportion of liver cancer cases and deaths due to infection with hepatitis B virus (HBV), hepatitis C virus (HCV), aflatoxin exposure, alcohol drinking and smoking in China in 2005. Study design: Systemic assessment of the burden of five modifiable risk factors on the occurrence of liver cancer in China using the population attributable fraction. Methods: We estimated the population attributable fraction of liver cancer caused by five modifiable risk factors using the prevalence data around 1990 and data on relative risks from meta-analyses, and large-scale observational studies. Liver cancer mortality data were from the 3rd National Death Causes Survey, and data on liver cancer incidence were estimated from the mortality data from cancer registries in China and a mortality/incidence ratio calculated. Results: We estimated that HBV infection was responsible for 65.9% of liver cancer deaths in men and 58.4% in women, while HCV was responsible for 27.3% and 28.6% respectively. The fraction of liver cancer deaths attributable to aflatoxin was estimated to be 25.0% for both men and women. Alcohol drinking was responsible for 23.4% of liver cancer deaths in men and 2.2% in women. Smoking was responsible for 18.7% and 1.0%. Overall, 86% of liver cancer mortality and incidence (88% in men and 78% in women) was attributable to these five modifiable risk factors. Conclusions: HBV, HCV, aflatoxin, alcohol drinking and tobacco smoking were responsible for 86% of liver cancer mortality and incidence in China in 2005. Our findings provide useful data for developing guidelines for liver cancer prevention and control in China and other developing countries.

THE LUMINOSITY-LINEWIDTH RELATION AS A PROBE OF THE EVOLUTION OF FIELD GALAXIES

  • GUHATHAKURTA PURAGRA;ING KRISTINE;RIX HANS-WALTER;COLLESS MATTHEW;WILLIAMS TED
    • 천문학회지
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    • 제29권spc1호
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    • pp.63-64
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    • 1996
  • The nature of distant faint blue field galaxies remains a mystery, despite the fact that much attention has been devoted to this subject in the last decade. Galaxy counts, particularly those in the optical and near ultraviolet bandpasses, have been demonstrated to be well in excess of those expected in the 'no-evolution' scenario. This has usually been taken to imply that galaxies were brighter in the past, presumably due to a higher rate of star formation. More recently, redshift surveys of galaxies as faint as B$\~$24 have shown that the mean redshift of faint blue galaxies is lower than that predicted by standard evolutionary models (de-signed to fit the galaxy counts). The galaxy number count data and redshift data suggest that evolutionary effects are most prominent at the faint end of the galaxy luminosity function. While these data constrain the form of evolution of the overall luminosity function, they do not constrain evolution in individual galaxies. We are carrying out a series of observations as part of a long-term program aimed at a better understanding of the nature and amount of luminosity evolution in individual galaxies. Our study uses the luminosity-linewidth relation (Tully-Fisher relation) for disk galaxies as a tool to study luminosity evolution. Several studies of a related nature are being carried out by other groups. A specific experiment to test a 'no-evolution' hypothesis is presented here. We have used the AUTOFIB multifibre spectro-graph on the 4-metre Anglo-Australian Telescope (AAT) and the Rutgers Fabry-Perot imager on the Cerro Tolalo lnteramerican Observatory (CTIO) 4-metre tele-scope to measure the internal kinematics of a representative sample of faint blue field galaxies in the red-shift range z = 0.15-0.4. The emission line profiles of [OII] and [OIII] in a typical sample galaxy are significantly broader than the instrumental resolution (100-120 km $s^{-l}$), and it is possible to make a reliable de-termination of the linewidth. Detailed and realistic simulations based on the properties of nearby, low-luminosity spirals are used to convert the measured linewidth into an estimate of the characteristic rotation speed, making statistical corrections for the effects of inclination, non-uniform distribution of ionized gas, rotation curve shape, finite fibre aperture, etc.. The (corrected) mean characteristic rotation speed for our distant galaxy sample is compared to the mean rotation speed of local galaxies of comparable blue luminosity and colour. The typical galaxy in our distant sample has a B-band luminosity of about 0.25 L$\ast$ and a colour that corresponds to the Sb-Sd/Im range of Hub-ble types. Details of the AUTOFIB fibre spectroscopic study are described by Rix et al. (1996). Follow-up deep near infrared imaging with the 10-metre Keck tele-scope+ NIRC combination and high angular resolution imaging with the Hubble Space Telescope's WFPC2 are being used to determine the structural and orientation parameters of galaxies on an individual basis. This information is being combined with the spatially resolved CTIO Fabry-Perot data to study the internal kinematics of distant galaxies (Ing et al. 1996). The two main questions addressed by these (preliminary studies) are: 1. Do galaxies of a given luminosity and colour have the same characteristic rotation speed in the distant and local Universe? The distant galaxies in our AUTOFIB sample have a mean characteristic rotation speed of $\~$70 km $s^{-l}$ after correction for measurement bias (Fig. 1); this is inconsistent with the characteristic rotation speed of local galaxies of comparable photometric proper-ties (105 km $s^{-l}$) at the > $99\%$ significance level (Fig. 2). A straightforward explanation for this discrepancy is that faint blue galaxies were about 1-1.5 mag brighter (in the B band) at z $\~$ 0.25 than their present-day counterparts. 2. What is the nature of the internal kinematics of faint field galaxies? The linewidths of these faint galaxies appear to be dominated by the global disk rotation. The larger galaxies in our sample are about 2"-.5" in diameter so one can get direct insight into the nature of their internal velocity field from the $\~$ I" seeing CTIO Fabry-Perot data. A montage of Fabry-Perot data is shown in Fig. 3. The linewidths are too large (by. $5\sigma$) to be caused by turbulence in giant HII regions.

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