간행물
한국지구과학회지 KCI 등재 The Journal of The Korean Earth Science Society
- 발행기관 한국지구과학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1225-6692 (Print)2287-4518 (Online)
- 수록기간 1979 ~ 2024
- 주제분류 자연과학 > 지구과학 자연과학 분류의 다른 간행물
- 십진분류KDC 450DDC 550
권호리스트/논문검색
제33권 제5호 (2012년 9월) 8건
1.
2012.09
구독 인증기관 무료, 개인회원 유료
To elucidate the mechanism associated with the development of heavy precipitation system, a field experiment was carried out in Jejudo (or Jeju Island) and Marado, Korea from 22 June to 12 July 2006. The synoptic atmospheric conditions were analyzed using the National Centers for Environmental Prediction-National Center for Atmospheric Research's (NCEP/NCAR) reanalyzed data, weather maps, and sounding data. The kinematic characteristics of each precipitation system were investigated by dual Doppler radar analysis. During the field experiment, data of four precipitation events with more than 20 mm rainfall were collected. In F case (frontal precipitation), a typical Changma front was dominant and the observation field was fully saturated. However there was no convective instability near the surface. LF case (low pressure accompanied with Changma front) showed strong convective instability near the surface, while a strong convergence corresponded to the low pressure from China accompanied with Changma front. In FT case (Changma front indirectly influenced by typhoon), the presence of a convective instability indicated the transport of near surface, strong additional moisture from the typhoon 'EWINIAR'. The convergence wind field was ground to be located at a low level. The convective instability was not significant in T case (precipitation of the typhoon 'EWINIAR'), since the typhoon passed through Jejudo and the Changma front was disappeared toward the northeastern region of the Korean peninsula. The kinematic (convergence and divergence) characteristics of wind fields, convective instability, and additional moisture inflow played important roles in the formation and development of heavy precipitation.
5,200원
2.
2012.09
구독 인증기관 무료, 개인회원 유료
One of the main problems concerning the shallow seismic survey is how to generate high frequency signals with large amplitudes using small seismic sources. If one could focus the seismic energy in the direction of the survey line, it will be much helpful in identifying the first break. In this research, we have used hammer as an impulsive source and compared the signal powers generated by different shapes of the hammer plates: circular, square, and rectangular. The experiment was conducted by calculating the power spectral density function to compare the frequency spectrum and signal power. In the direction perpendicular to the long side of the rectangular plate, the largest seismic energy with the highest frequency was achieved even with the same weights of hammer plates. Our conclusion is that it is more efficient to use a rectangular plate than a circular (or square) one when conducting a 2-D shallow seismic survey.
4,000원
3.
2012.09
구독 인증기관 무료, 개인회원 유료
The OGS model is configured and used for simulation of the LASGIT project. The modeling conditions and the simulation results from the previous work by Walsh and Calder (2009) are analyzed to see if the simulation configuration is done correctly and to apply for the LASGIT project. Except for the unrealistic modeling conditions used previously, the simulation results successfully demonstrated helium propagation that is typical for the two-phase flow. The results indicated that the relations of capillary pressure and the relative permeability against water saturation used previously should be updated. An elaborated simulation with more realistic parameters should be used to improve the weak points of preliminary work.
4,000원
4.
2012.09
구독 인증기관 무료, 개인회원 유료
The objective of this paper is to apply a newly developed wavelet-based semblance filtering and eigenvalue analysis to investigate the geomagnetic variations in some micro-earthquakes that had occurred in the Korean Peninsula. The wavelet-based filtering showed improved results in delineating the geomagnetic variations in relation to earthquake events from their background field. In addition, the eigenvalues analysis was also useful for the interpretation of three components geomagnetic fields during the earthquake events. The wavelet-based semblance analysis showed a prominent result for short-term geomagnetic variation related to the earthquake event, and the eigenvalue analysis was feasible to long-term geomagnetic variation. Considering the fact that the basement rock of the Korean Peninsula has a highly resistive electrical structure, it seems to be possible for small magnitude earthquakes to generate some distinguished geomagnetic variations.
4,600원
5.
2012.09
구독 인증기관 무료, 개인회원 유료
The purpose of this study is to investigate the characteristic changes of the Changma season in the 2000s. To accomplish this goal, we have used daily rainfall data collected over nearly 40 years (1971 to 2010). The average summer precipitation data including the Changma season were collected from 16 weather stations that are placed across the three major regions (i.e. central region, southern region, and Jeju region) as Korea Meteorological Administration divided. These precipitation data were analyzed to find out characteristic changes of the Changma season. Results of the precipitation data comparison among the major regions that, monthly average precipitation in the central region was the highest in July; its precipitation tended to increase from May to September. In the southern region, the precipitation amount was lowest in June and tended to increase in May, September, and August. In the Jeju region, the precipitation has been the highest in June and July for the past 30 years, whereas September has been highest month in the last 10 years. The precipitation amount in the Jeju region decreased both in June and July, whereas it tended to grow in May, August and September. A correlation coefficient formula by Karl Pearson has been used to find out correlations between the Changma season and the precipitation of the major regions in 2000s and normal years. It was found that the correlation coefficient has decreased from 0.723 to 0.524 in the 2000s (2001 to 2010) compared to normal years (1971 to 2000).
4,300원
6.
2012.09
구독 인증기관 무료, 개인회원 유료
The Mesozoic leucocratic granite in the northeastern margin of the Taebaeksan Basin was transformed to protomylonite and mylonite. Mylonitic foliations generally strike to NWWNW and dip to NE with the development of a sinistral strike-slip (top-to-the-northwest) shear sense. Grain-size reduction of feldspar in the mylonitized leucocratic granite occurred due to fracturing, myrmekite formation and neocrystallization of albitic plagioclase along the shear fractures of K-feldspar porphyroclasts. As the deformation proceeded, compositional layering consisting of feldspar-, quartz- and/or muscovite-rich layers developed in the mylonite. In the feldspar-rich layer, fine-grained albitic plagioclase and interstitial K-feldspar were deformed dominantly by granular flow. On the other hand, quartz-rich layers containing core-mantle and quartz ribbons structures were deformed by dislocation creep. Based on calculations from conventional two-feldspar and ternary feldspar geothermometers, mylonitization temperatures of the leucocratic granite range from 360 to 450˚C. It thus indicates that the mylonitization has occurred under greenschist-facies conditions. Based on the geochemical features and previous chronological data, the leucocratic granite was emplaced during the Middle Jurassic at volcanic arc setting associated with crustal thickening. And then the mylonitization of the granite occurred during the late Middle to Late Jurassic (150-165 Ma). Therefore, the mylonitization of the Jurassic granitoids in the Taebaeksan Basin was closely related to the development of the Honam shear zone.
4,900원
7.
2012.09
구독 인증기관 무료, 개인회원 유료
This study explored ways to implement a competencies-based curriculum in schools by reviewing exemplary cases that have introduced Key Competencies (KCs) in the school science curriculum. Since the OECD redefined key competencies as 'what people should know and do in order to lead a successful life in a well-functioning society', many countries have emphasized the use of a competencies-based curriculum. Foreign and domestic classroom cases, which have used a competencies-based curriculum in science teaching, were collected and analyzed. Through open-ended interviews with teachers and principals, we investigated changes of teachers' professional knowledge and practice that were evident as a result of the implementation of competencies-based curriculum in science class. Foreign science teachers suggested ways to relate competencies-based curriculum and science curriculum including maintaining a balance between competencies-based curriculum and content-based curriculum. They also integrated KCs into all subject-based curriculums, gave priority to KCs over subject matter knowledge, and developed KCs through teaching science contents that students wanted to learn. On the other hand, Korean science teachers suggested reconstructing competencies-based curriculum by extracting common attributes from the existing subject areas. They also made KCs realized through content teaching, and developed various KCs within science contexts. Implications of the competencies-based curriculum for science teaching and learning were discussed at the end.
4,000원
8.
2012.09
구독 인증기관 무료, 개인회원 유료
This study aimed to investigate the characteristics of pre-service elementary teachers' understanding about scientific inquiry in terms of designing exploration and reasoning that is used to formulate explanations based on evidence. The research context was an open inquiry with using the Science Writing Heuristic (SWH) template in which participant students were not provided with inquiry questions. As data, lab. 39 pre-service elementary teachers participated in this study while taking their science methods course. Analyses of the reports were framed by the cognitive processes of inquiry (Chinn and Malhotra, 2002) and each report was coded and analyzed by the framework of inquiry (Tytler and Peterson, 2004). Results showed that groups' works that utilized the SWH template encouraged the participants to interact each other about scientific inquiry. They came up with more relevant and testable questions for their scientific inquiry. It implicates that children will be able to have chances of testing their own questions more properly by using the SWH template in science classes just as the participants did in this study. The use of the SWH template would help pre-service teachers to teach appropriately how to test inquiry questions to their students in the future. Discussion was made to figure out the characteristics or Korean pre-service elementary teachers' understanding about scientific inquiry.
4,000원
