• 제목/요약/키워드: Korean geophysics

검색결과 1,236건 처리시간 0.028초

DISTANCES OF GLOBULAR CLUSTERS BASED ON HIPPARCOS PARALLAXES OF NEARBY SUBDWARFS

  • SAAD SOMAYA MOHAMED;LEE SANG-GAK
    • 천문학회지
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    • 제34권2호
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    • pp.99-109
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    • 2001
  • In the present study we have determined the distance moduli for seven globular clusters M2, M3, Ml0, M12, NGC 2808, NGC 6229, and NGC 6752, whose metallicities are in the range -1.54 < [Fe/H] < -1.10. We have derived distances for them by the main-sequence fitting method using a sample of local subdwarfs, whose accurate parallaxes are taken from the Hipparcos Catalog. The derived distance moduli are 15.52 for M2, 14.98 for M3, 14.23 for Ml0, 14.03 for M12, 15.56 for NGC 2808, 17.34 for NGC 6229, and 13.29 for NGC 6752.

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Analysis of the Program for Training Pre-service Earth Science Teachers: Focusing on College Curriculum

  • Ahn, Yumin;Shin, Yoonjoo
    • 한국지구과학회지
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    • 제41권4호
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    • pp.391-404
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    • 2020
  • This study identified and examined earth science education department programs in Korea. Major courses provided by 11 universities and their course requirements were analyzed, and the main research results are as follows. First, many basic courses, other major requisite, and elective courses are provided in geology, astronomy, and atmospheric science. oceanography, geophysics, earth environmental science, and natural disaster and energy resources had fewer major requisite courses provided in addition to basic courses, and few elective courses were offered. Second, many courses in science education focused on earth science, while others focused on general science and there were few courses that covered education theory regarding the specific subject. Third, science course application requirements emphasized the understanding of science in general or of earth science specifically. From the above results, additional studies are proposed to reflect on the current state and supplement these programs.

Improved Free-air Gravity Anomalies by Satellite Altimetry

  • Kim, Jeong-Woo;Roman, Daniel-R.
    • 대한원격탐사학회지
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    • 제17권4호
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    • pp.297-305
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    • 2001
  • Ocean satellite altimetry-implied free-air gravity anomalies have had the shortest wavelengths removed during the processing to generate the optimal solution between multiple radar altimeter missions. ERS-1 168day mission altimetry was residualized to a reference geoid surface generated by integrating Anderson & Knudsen’s free-air gravity anomalies for the Barents Sea. The altimetry tracks were reduced and filtered to extract the shortest wavelengths (between 4 and 111 km) from both ascending and descending tracks, respectively. These data were recombined using existing quadrant-swapping techniques in the wavenumber domain to generate a correlated, high frequency gravity field related to the local geologic sources. This added-value surface adjusted the reference free-air gravity anomalies to better reflect features in the gravity field at a wavelength related to the distance between altimetry ground tracks.

Outbreak of Water Mass into the East Coast of Japan Evident in the Kuroshio Extension in June 2001

  • Yang Chan-Su;Suga Toshio
    • 대한원격탐사학회지
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    • 제20권5호
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    • pp.307-313
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    • 2004
  • The trajectories of 8 autonomous profiling floats deployed in the Kuroshio Extension region in February 2001 are used to depict the circulation pattern at the surface and 2000db. The corresponding sea surface topography maps created from satellite altimeter and dynamic height climatology were compared with the tracks of nearly coincident floats and were found to agree well in most cases except for the period June 5 to 16 2001. It is shown that over the period the conspicuous breakaway of the floats from an expected path is possibly associated with the abnormal path of the Kuroshio Extension such as an outbreak event, as revealed by AVHRR infrared and SeaWiFS chlorophyll-a images and cruise data in cross sections.

R을 이용한 지진자료 처리 (Seismic Data Analysis using the R)

  • 정태웅;;윤숙영
    • 지구물리와물리탐사
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    • 제11권4호
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    • pp.379-384
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    • 2008
  • R언어는 통계적 계산과 그래픽을 위한 무료 소프트웨어로 유닉스 뿐 아니라 MS 윈도우상에서도 잘 구동되며, 명령어가 이해하기 쉽고 명령에 대한 Help 기능이 컴퓨터상에서 대화형으로 잘 구비되어 있다. 수많은 패키지에 의해 여러 분야에서 활용되고 있는데, 'RSEIS' 패키지를 사용하면 그래픽에 의한 지진자료처리 작업이 매우 수월하여 그 예를 소개한다.

Combining Geostatistical Indicator Kriging with Bayesian Approach for Supervised Classification

  • Park, No-Wook;Chi, Kwang-Hoon;Moon, Wooil-M.;Kwon, Byung-Doo
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.382-387
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    • 2002
  • In this paper, we propose a geostatistical approach incorporated to the Bayesian data fusion technique for supervised classification of multi-sensor remote sensing data. Traditional spectral based classification cannot account for the spatial information and may result in unrealistic classification results. To obtain accurate spatial/contextual information, the indicator kriging that allows one to estimate the probability of occurrence of classes on the basis of surrounding observations is incorporated into the Bayesian framework. This approach has its merit incorporating both the spectral information and spatial information and improves the confidence level in the final data fusion task. To illustrate the proposed scheme, supervised classification of multi-sensor test remote sensing data set was carried out.

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단보: 감마선 스펙트로미터 자료의 짙을 향상시키기 위한 방사성원소 비의 사용에 대하여 (Short note: on the use of radioelement ratios to enhance gamma-ray spectrometric data)

  • Minty, Brian
    • 지구물리와물리탐사
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    • 제14권1호
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    • pp.116-120
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    • 2011
  • 방사성원소 비는 방사성 특성의 미묘한 변화를 지도형태의 자료로 만드는데 유용하다. 그러나 방사성원소비를 계산하는 전통적인 방법은 만약 비를 구성하는 방사성원소 중 단 하나라도 평균값에 비해 적은 분산을 갖는 농축 추정치를 갖는다면 방사성원소비 지도 작성에 중요한 영향을 주지 못하게 되어 커다란 한계를 갖게 된다. 이와는 달리 만약 비를 구하기 전에 분자와 분모를 모두 거의 같은 평균과 분산으로 정규화 시켜준다면 방사성원소들은 지도가 작성되는 영역에서 원소들 사이의 차이를 부각시키는데 동일하게 기여하게 될 것이다.

Sub-surface imaging and vector precision from high resolution down-hole TEM logging

  • Chull, James;Massie, Duncan
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2005년도 제7회 특별심포지움 논문집
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    • pp.11-18
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    • 2005
  • Filament inversion routines are highly effective for target definition whenever total-field DHTEM vectors can be obtained using three-component logging tools. However most cross-hole components contain significant noise related to sensor design and errors in observation of probe rotation. Standard stacking methods can be used to improve data quality but additional statistical methods based on cross-correlation and spatial averaging of orthogonal components may be required to ensure a consistent vector migration path. Apart from assisting with spatial averaging, multiple filaments generated for successive time-windows can provide additional imaging information relating to target geometry and current migration. New digital receiver systems provide additional time-windows to provide better tracking options necessary for high-resolution imaging of this type.

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DSR 연산자에 의한 파동장 외삽을 이용한 중합전 데이터밍 (Prestack Datuming by Wavefield Depth Extrapolation using the DSR Equation)

  • 지준
    • 지구물리와물리탐사
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    • 제2권1호
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    • pp.54-62
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    • 1999
  • 본 논문은 파동장의 심도방향으로의 외삽(extrapolation)을 사용한 중합전 데이터밍 기법을 소개한다. 데이터밍 알고리즘의 유도를 위해, 우선 평면에 정의되어 있는 파동장을 임의의 굴곡을 갖는 면으로 외삽을 수행하는 모델링 연산자를 대수학적으로 구한 후, 이러한 모델링 연산자와 어드조인트(adjoint)관계에 있는 연산자를 대수학적으로 구하여 데이터밍 연산자를 얻게된다. 본 논문에서 사용된 취합전 모델링 연산자는 이미 널리 쓰이고 있는 중합전 마이그레이션(prestack migration) 중의 하나인 survey sinking 방법의 모델링에 해당하는 double square root(DSR)식이 사용되었다.

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지자기 구조해석에 의한 해저년대의 측정과 해산의 자기기기반구조의 연구 (Age Dating of Seafloor by Interpretation of Geomagnetic Structure and Study on the Magnetic Basement of the Sea Mount)

  • 신기철;한건모
    • 한국해양공학회지
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    • 제4권1호
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    • pp.35-42
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    • 1990
  • The area where age dating of the seafloor and interpretation of geomagnetic basic structure are conducted is also important in the aspect of geophysics. Near the sea mount (water depth to the top is 3900m and 6500m to the bottom), there are Mesozoic magnetic lineations at the sea-side flank along the trench axis. A two dimensional model analysis of Talwani and Heirtzler(1964) and a three dimensional model analysis of Talwani are performed by using data obtained from the marine proton magnetometer. Distribution, direction of the lineation, amplitude and period of magnetic anomaly are correlated and analysed with speed of the plate movement and lineation of the sea mount. In the west and north-west Pacific there are lots of huge sea mounts retaining the history of oceanic crust. This indicates that geomagnetic basis subsided into the oceanic crust and has interest in the aspects of the isostasy theory of the gravity.

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