간행물

한국지구과학회지 KCI 등재 The Journal of The Korean Earth Science Society

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제31권 제5호 (2010년 9월) 11

1.
2010.09 구독 인증기관 무료, 개인회원 유료
The Pyeongan Supergroup can be divided into seven lithostratigraphic units (Moscovian to Early Triassic?) in the Samcheok coalfield and four lithostratigraphic units (Bashkirian to Artinskian) in the Yeongwol coalfield of South Korea. On the basis of fusulinid biostratigrapic data in the Yeongwol coalfield, the boundary between the Carboniferous and Permian strata of the Pyeongan Supergroup has been considered as unconformity since the Kasimovian and Gzhelian strata are missing. Protriticites and Triticites, which are the cosmopolitan index fusulinids indicating the Kasimovian and Gzhelian age, are not found from the uppermost part of the Geumcheon and Pangyo Formations. Recently some fusulinids such as Xenostaffella koreaensis, Hanostaffella magna, and Fusulina danyangensis found from the uppermost part of the Geumcheon and Pangyo Formations are recognized as the early Kasimovian-type fusulinids, although the upper Kasimovian- to Gzhelian-type fusulinids are still missing.
4,200원
2.
2010.09 구독 인증기관 무료, 개인회원 유료
Some materials belonging to the Leptostrobus myeongamensis Kim were found in the Upper Triassic Amisan Formation, Nampo Group, Korea. This species is closely associated with the foliage of Czekanowskia ex gr. rigida Heer. Although none of Leptostrobus myeongamensis Kim has been found in organic connection with Czekanowskia leaves, it is considered that they belong to the same taxa based on their common occurrence. The occurrence of Leptostrobus myeongamensis Kim from the Late Triassic floras of Korea is one of the oldest records in the Mesozoic floras found in the world.
4,000원
3.
2010.09 구독 인증기관 무료, 개인회원 유료
Spatial estimation of environmental variables has been regarded as an important preliminary procedure for decision-making. A minimum variance criterion, which has often been adopted in traditional kriging algorithms, does not always guarantee the optimal estimates for subsequent decision-making processes. In this paper, a geostatistical framework is illustrated that consists of uncertainty modeling via stochastic simulation and risk modeling based on loss functions for the selection of optimal estimates. Loss functions that quantify the impact of choosing any estimate different from the unknown true value are linked to geostatistical simulation. A hybrid loss function is especially presented to account for the different impact of over- and underestimation of different land-use types. The loss function-specific estimates that minimize the expected loss are chosen as optimal estimates. The applicability of the geostatistical framework is demonstrated and discussed through a case study of copper mapping.
4,200원
4.
2010.09 구독 인증기관 무료, 개인회원 유료
The population of House sparrow (Passer domesticus), once a very common bird, has declined markedly in most parts of the world including India. Sparrows were distributed widely in the district Hoogly, West Bengal, India. However over the past few decades, they became not so common in this part of the wo rld. A study has been conductedto establish the database for their current population and to assess the possible causes of their decline at Bandel (22˚52'22"N/88˚22'53"E) placed beside the river Hoogly from September 2008 to May 2009. After prolonged searching, a relatively dense population of sparrow (total subject 270) was found in busy areas of railway station and a nearby market in Bandel. The behavior of these birds was studied extensively from early morning to late night. The noise level of the area varied from 35 to 95 dB with an average of 70.6 dB from 04:30 am-10:30 pm, IST. It was also observed that the sparrows took rest on the site of the tree where the illumination level was low (30-45 lux). Sparrows residing at the Bandel station are habituated with the loud noise, being undisturbed by passing trains. Thus, it can be concluded that in spite of heavy noise of trains, crowdy travelers, and lack of nest sites, they remain at the station because of availability of food in the nearby roadside market. Based on this observation, sound pollution and availability of food are not responsible for their decline.
4,000원
5.
2010.09 구독 인증기관 무료, 개인회원 유료
A probability prediction model for tropical cyclone (TC) genesis in the Northwestern Pacific area was developed using the logistic regression method. Total five predictors were used in this model: the lower-level relative vorticity, vertical wind shear, mid-level relative humidity, upper-level equivalent potential temperature, and sea surface temperature (SST). The values for four predictors except for SST were obtained from difference of spatial-averaged value between May and January, and the time average of Niño-3.4 index from February to April was used to see the SST effect. As a result of prediction for the TC genesis frequency from June to December during 1951 to 2007, the model was capable of predicting that 21 (22) years had higher (lower) frequency than the normal year. The analysis of real data indicated that the number of year with the higher (lower) frequency of TC genesis was 28 (29). The overall predictability was about 75%, and the model reliability was also verified statistically through the cross validation analysis method.
4,200원
6.
2010.09 구독 인증기관 무료, 개인회원 유료
Real-time rainfall monitoring is of great practical importance over the highly populated Indochina area, which is prone to natural disasters, in particular in association with rainfall. With the goal of d etermining near real-time half-hourlyrain estimates from satellite, the three-layer, artificial neural networks (ANN) approach was used to train the brightness temperatures at 6.7, 11, and 12-μm channels of the Japanese geostationary satellite MTSAT against passive microwavebased rain rates from Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and TRMM Precipitation Radar (PR) data for the June-September 2005 period. The developed model was applied to the MTSAT data for the June-September 2006 period. The results demonstrate that the developed algorithm is comparable to the PERSIANN (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks) results and can be used for flood monitoring across the Indochina area on a half-hourly time scale.
4,000원
7.
2010.09 구독 인증기관 무료, 개인회원 유료
Sea surface wind field was retrieved from high-resolution SIR-C SAR data by using CMOD algorithms off the east coast of Korea. In order to extract wind direction information from SAR data, a two-dimensional spectral analysis method was applied to the normalized radar cross section of the image. An 180˚-ambiguity problem in the determination of wind direction was solved by selecting a direction nearest to the wind vector of the ECMWF reanalysis data. Comparison of the wind retrieval patterns with the ECMWF and NCEP/NCAR dataset showed RMS errors in the range of 1.30 to 1.72 ms-1. In contrast, comparison of wind directions revealed large errors of greater than 60˚, which is enormously higher than the permitted limit of about 20˚ for satellite scatterometer winds. Compared with wind speed results from different algorithms, wind vectors based on commonly-used CMOD4 algorithm showed good agreement with those derived by other algorithms such as CMODIFR2 and CMOD5, particularly at medium winds from 4 to 8 ms-1. However, apparent discrepancy appeared at low winds (〈 4 ms-1). This study also addressed an importance of accurate wind direction data to improve the accuracy of wind speed retrieval and discussed potential causes of wind retrieval errors from SAR data.
4,500원
8.
2010.09 구독 인증기관 무료, 개인회원 유료
In this research, we investigated the historical development and ways of improvement of the teacher employment test (TET, hereafter) in Korea. This paper consists of three parts. The first part details the secondary science teacher education system in Korea. The second part elaborates upon the development of the TET since 1990's. The third part provides conclusion by addressing ways to improve science teacher education and employment systems in Korea. After all, the keen competition for teacher education and the demanding entry test ensure that secondary science teachers are selected from a pool of candidates with high academic achievement. Korean teacher employment system in general places more weight on subject knowledge. Although we cannot simply conclude that Korean science teachers must have profound knowledge in the subject matter and are competent in pedagogy, it stands to reason that the teachers could be more competent in performing their roles than those of many western countries with an acute shortage of teachers. We also suggested future directions and ways of improvement regarding teacher education and the TET in Korea.
4,300원
9.
2010.09 구독 인증기관 무료, 개인회원 유료
The purposes of this case study were (1) to explore one experienced teacher's views on Earth Systems Education and (2) to describe and document the characteristics of the Earth Systems Education (ESE) curriculum provided by an exemplary middle school science teacher, Dr. J. All the essential pieces of evidence were collected from observations, interviews with the experienced teacher and his eighth grade students, informal conversations, document analysis, and field notes. The NUD*IST for MS Windows was used for an initial data reduction process and to narrow down the focus of an analysis. All transcriptions and written documents were reviewed carefully and repeatedly to find rich evidence through inductive and content analysis. The findings revealed that ESE provided a conceptual focus and theme for organizing his school curriculum. The curriculum offered opportunities for students to learn relevant local topics and to connect the classroom learning to the real world. The curriculum also played an important role in developing students' value and appreciation of Earth systems and concern for the local environment. His instructional strategies were very compatible with recommendations from a constructivist theory. His major teaching methodology and strategies were hands-on learning, authentic activities-based learning, cooperative learning, project-based learning (e.g., mini-projects), and science field trips. With respect to his views about benefits and difficulties associated with ESE, the most important benefit was that the curriculum provided authentic-based, hands-on activities and made connections between students and everyday life experiences. In addition, he believed that it was not difficult to teach using ESE. However, the lack of time devoted to field trips and a lack of suitable resource materials were obstacles to the implementation of the curriculum. Implications for science education and future research are suggested.
5,700원
10.
2010.09 구독 인증기관 무료, 개인회원 유료
This study aimed to explore how to characterize the earth science inquiry in schools in terms of science teaching interaction and constructivist teaching practice. The constructivist teaching practices were analyzed with Reformed Teaching Observation Protocol (RTOP) in three aspects including (1) student oriented class implementation, (2) subject knowledge and representation, and (3) classroom communication. Fourteen earth science classes were observed and scored with RTOP. The class was evaluated to be transitional stage in terms of constructivist teaching, e.g., moving toward student-centered teaching practice. Especially, Korean teachers tend to lean their classes more on propositional knowledge than procedural knowledge. To interpret science teaching interactions, an earth science teacher with a RTOP top rank was selected. Her class was then videotaped for detailed analysis. I adopted the analytical framework of communicative approaches and discourse patterns among the five aspects of interactions presented by Mortimer and Scott (2003). It was found that this earth science teacher used more authoritative patterns than the dialogic. In addition, she used IRE discourse pattern more frequently. Interestingly, teachers interacted with their students more frequently in the form of repeated (or IRE chain pattern), that is IRFRF (teacher initiation-student response-teacher feedback-student response-teacher feedback) in the context of dialogic communicative approaches, while simple IRE occurred in an authoritative approach. In earth science classrooms, typical interaction may well be constructed in the form of IRFRF chains to allow students free conjectures and abduction.
4,000원
11.
2010.09 구독 인증기관 무료, 개인회원 유료
This study presents the development of an elevated subsidence inversion over a surface low pressure system, which was formed along the Changma front or Meiu-Baiu front. The results of our analysis strongly suggest that the inversion is dissimilar to those formed in anticyclonic situations but is instead similar to the onion-shaped sounding found in wake low. The present analysis indicates that the observed elevated inversion resulted from the intrusion of stratospheric air associated with tropopause folding.
4,000원