• 제목/요약/키워드: observational

검색결과 1,772건 처리시간 0.022초

Nudging of Vertical Profiles of Meteorological Parameters in One-Dimensional Atmospheric Model: A Step Towards Improvements in Numerical Simulations

  • Subrahamanyam, D. Bala;Rani, S. Indira;Ramachandran, Radhika;Kunhikrishnan, P. K.
    • Ocean Science Journal
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    • 제43권4호
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    • pp.165-173
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    • 2008
  • In this article, we describe a simple yet effective method for insertion of observational datasets in a mesoscale atmospheric model used in one-dimensional configuration through Nudging. To demonstrate the effectiveness of this technique, vertical profiles of meteorological parameters obtained from GLASS Sonde launches from a tiny island of Kaashidhoo in the Republic of Maldives are injected in a mesoscale atmospheric model - Advanced Regional Prediction System (ARPS), and model simulated parameters are compared with the available observational datasets. Analysis of one-time nudging in the model simulations over Kaashidhoo show that incorporation of this technique reasonably improves the model simulations within a time domain of +6 to +12 Hrs, while its impact on +18 Hrs simulations and beyond becomes literally null.

포스트 모더니즘적 관점에서 살펴본 예비교사의 관찰 실습경험 (Pre-service Teachers' Observational Experience From Post-modernsist Perspective)

  • 안효진
    • 한국생활과학회지
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    • 제21권2호
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    • pp.197-211
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    • 2012
  • This purpose of this study was to explore the meaning and significance of experiences encountered by preservice teachers' during their observational practicum at day care centers. This study involved one cohort of 32 junior students who were majoring in early childhood education at a 4-year university. Data was analyzed using qualitative research methodology. The findings were as follows: 1) the meaning and significance of students'experiences related to observing children was to develop a trusting relationship with children and a cooperative relationship with teachers in an unfamiliar context. 2) the meaning and significance of students'experiences in observing children was to understand the children and their circumstance. 3) the meaning and significance of students'experience in observing children was to understand the importance of listening in child-teacher spoken interaction.

Building on successful existing collaborations with the University of Arizona

  • Kim, Jinyoung Serena
    • 천문학회보
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    • 제40권1호
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    • pp.70.2-70.2
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    • 2015
  • Scientific collaborations and observational programs have been on-going between astronomers in Korea and the Steward Observatory/University of Arizona. I will present such existing collaboration models/examples between research groups or individuals and astronomers in KASI or in other institutions and universities in Korea. Building on existing collaborations we would like to further develop opportunities for future scientific collaborations and encourage scholarly exchanges between students, researchers, and faculty members in Korea and Steward Observatory/University of Arizona. In this talk I will also discuss current status of observational programs of Korean astronomers using U of A facilities (MMT and Magellan), as well as successful collaboration examples between Steward Observatory and astronomical institutions in other countries.

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Introduction to 1M telescope of Deokheung Optical Astronomy Observatory, National Youth Science Center (NYSC)

  • Kang, Wonseok;Lee, Sang-Gak;Kwon, Sun-Gill
    • 천문학회보
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    • 제40권1호
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    • pp.86.4-87
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    • 2015
  • We will soon complete the installation of 1m telescope at Deokheung Optical Astronomy Observatory (DOAO), National Youth Space Center (NYSC). Before the test observation with NYSC 1m telescope, we present the specs of the 1M telescope and observational conditions of the DOAO site, such as the seeing data at DOAO and the atmospheric extinction coefficients obtained from the observations of standard stars and stellar clusters with 120mm and 150mm refractor in 2014. Since atmospheric extinction coefficients depend on the observational instruments as well as the atmospheric conditions of the site, the improved data with NYSC 1m telescope will be obtained right after the completion of 1M telescope installation. We are planning to invite all astronomers to use 1m telescope for their sciences via regular proposal processes in this year.

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FARADAY ROTATION OBSERVATIONS OF MAGNETIC FIELDS IN GALAXY CLUSTERS

  • CLARKE TRACY E.
    • 천문학회지
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    • 제37권5호
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    • pp.337-342
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    • 2004
  • The presence of magnetic fields in the intracluster medium in clusters of galaxies has been revealed through several different observational techniques. These fields may be dynamically important in clusters as they will provide additional pressure support to the intracluster medium as well as inhibit transport mechanisms such as thermal conduction. Here, we review the current observational state of Faraday rotation measure studies of the cluster fields. The fields are generally found to be a few to 10 $\mu$G in non-cooling core clusters and ordered on scales of 10 - 20 kpc. Studies of sources at large impact parameters show that the magnetic fields extend from cluster cores to radii of at least 500 kpc. In central regions of cooling core systems the field strengths are often somewhat higher (10 - 40 $\mu$G) and appear to be ordered on smaller scales of a few to 10 kpc. We also review some of the recent work on interpreting Faraday rotation measure observations through theory and numerical simulations. These techniques allow us to build up a much more detailed view of the strength and topology of the fields.

STANDARD STELLAR MODELS; $\alpha$ CEN A AND B

  • KIM YONG-CHEOL
    • 천문학회지
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    • 제32권2호
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    • pp.119-126
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    • 1999
  • The standard stellar models for $\alpha$ Cen A and B have been constructed without resorting to the arbitrary constraint of the Solar mixing length ratio. Assuming that the chemical compositions and the ages of the two stars are the same, series of models have been constructed. Using the observational constraints, [Z/X], we were able to constrain the number of the 'possible' models. We find that utilizing the observational constraints of [Z/X] the best models for $\alpha$ Cen system are with the initial Z = 0.03, X = 0.66$\~$0.67. In particular, the primary and the secondary stars may have the same mixing length ratio 1.6$\~$1.7, which is the same as that of the calibrated Solar model. And, the age of the system is about 5.4 Gyr. Finally, the large spacing of the p-modes is predicted to be 104 $\pm$ 4$\mu$Hz for $\alpha$ Cen A.

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뉴로 관측기를 이용한 교류서보 전동기 제어 (AC Servo Motor Control Using Neuro Observer)

  • 윤광호;김상훈;김낙교;남문현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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    • pp.69-71
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    • 2004
  • DC servo motors have a defect that they need a periodical maintenance because of a brush commutation and also they have a difficulty at high speed operation. In this reason, the use of AC Servo motors are increasing these days. In this paper, a proposed neuro observer is applied to speed control of AC servo motor. The proposed observer complement a problem that occur from increase of gain of High-gain observer in proportion to the square number of observable state variables. And also, the proposed observer can tune the gain obtained by differentiating observational error automatically by using the backpropagation training method to stabilize the observational speed. The excellence and feasibility of the proposed observer is proved by making a comparison test between the proposed observer and the others applied to the same AC servo motor.

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경희대학교 천문대의 천체관측 자료처리용 프로그램 개발 (DEVELOPMENT OF A COMPUTER PROGRAM FOR ASTRONOMICAL IMAGE DATA PROCESSING BY OBSERVATIONAL EQUIPMENT IN ASTRONOMICAL OBSERVATORY OF KYUNG HEE UNIVERSITY)

  • 김갑성
    • 천문학논총
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    • 제10권1호
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    • pp.135-146
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    • 1995
  • We have developed a graphic software for image processing of astronomical data obtained by observational equipment in Astronomical Observatory of Kyung Hee University. The essential hardware for running our computer program is simply composed of a PC with the graphic card to handle 256 colors and the color graphic monitor, including CCD camera system. Our software has been programmed in WINDOWS to provide good environments for users, by using various techniques of image processing on astronomical image data recorded in FITS format by KHCCD program(Jin and Kim, 1994) with a compressional mode. We are convinced that our results will be a fundamental and useful technique in the construction of data processing system and can be effectively used in any other observatories, as well as in data processing system of Kyung Hee University.

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