• Title/Summary/Keyword: Earth unit

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A Comparative Study on the Earth Science Curricula at High School Level in Foreign Countries (외국의 고등학교 지구과학 교육과정의 비교 연구)

  • Kwon, Chi-Soon;Hwang, Kyung-Hee
    • Journal of The Korean Association For Science Education
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    • v.10 no.2
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    • pp.55-66
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    • 1990
  • This study aimed at identifying the characteristics of current Earth Science Curricula in several countries in terms of their format, objectives and contents and discussing about them. The curricula(including textbooks) were collected from 6 countries The United States of America, England, Australia, Japan and The Republic of China. Here are the results of this study ; 1. Earth Science should be teached in high school and assigned at least 8-10 unit. 2. In Earth Science objectives, scientific inquiry methods through observation and experiment and mutual relationship among science, technology and society must be stressed. 3. The contents of Earth Science must did with experimental and activity rather than understanding in order to induce students to how more intersts in Earth Science. 4. There is a growing tendency for Earth Science Education to be attached importance to life environment and career education.

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Characteristics and Stratigraphy of Late Quaternary Sediments on a Macrotidal Mudflat Deposit of Namyang Bay, Western Coast of Korea

  • Lim, D. I.;Choi, J. Y.;Jung, H. S.
    • Journal of the Korean earth science society
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    • v.24 no.1
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    • pp.46-60
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    • 2003
  • In Namyang Bay of western Korea, macrotidal-flat deposits are divisible into three late Quaternary units: Unit M1 of upper marine mud, Unit T1 of middle siderite-bearing terrestrial clay, and Unit M2 of lower marine mud. Unit M1 represents typical Holocene intertidal mudflat deposits, showing a coarsening-upward textural trend. It probably resulted from the continual retrogradation of tidal flat during the mid-to-late Holocene sea-level rise. Reddish brown-color Unit T1 consists of homogeneous clay with abundant freshwater siderite grains and plant remains. Unit T1 is clearly separated from the overlying Unit M1 by a sharp lithologic boundary. Radiocarbon age, siderite grains and lithologic features indicate that Unit T1 is originated from freshwater bog or swamp deposition infilling the localized topographic lows during the early Holocene age. Overlain unconformably by early Holocene swamp clay, Unit M2 is orange to yellow in color and mottled, suggesting significant degree of weathering during the sea-level lowstand. Such subaerial oxidation is confirmed in the vertical profiles of geotechnical properties, clay mineral assemblages and magnetic susceptibility. Unit M2 appears to be correlated with the upper part of the late Pleistocene tidal deposits developed along the western Korean coast. The sedimentary succession of the Namyang-Bay tidal-flat deposit provides stratigraphic information for the Holocene-late Pleistocene unconformity and also permits an assessment of the preservation potential of the late Pleistocene marginal marine deposit along the western coast of Korea.

Late Quaternary Stratigraphy and Depositional Environment of Tidal Sand Ridge Deposits in Gyeonggi Bay, West Coast of Korea (서해 경기만 조석사주 퇴적층의 제4기 후기 층서 및 퇴적환경)

  • Choi, Jae-Yong;Kwon, Yi-Kyun;Chung, Gong-Soo
    • Journal of the Korean earth science society
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    • v.33 no.1
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    • pp.1-10
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    • 2012
  • Analysis on high-resolution seismic and core data reveals that the sedimentary strata in Gyeonggi Bay consists of four sedimentary units (Unit I-IV, from top to bottom) formed during the late Quaternary period. Unit I is interpreted as sediments of tidal flat and channel-fill deposits, formed during the Holocene transgression. Unit II is divided into shallow-marine facies unit in offshore area and channelized fluvial to estuarine facies unit in nearshore sand ridge and tidal flat. Unit III is considered as tidal flat deposits with the uppermost severely weathered and oxydized layers. This unit is composed of shallow marine sedimentary successions formed during the MIS-5 highstand. The lowermost Unit IV rests on Mesozoic basement rocks, considered as the shallow marine and shelf deposits formed before the MIS-5 lowstand.

Analysis of influence factors on the seismic earth pressure acting on gravity walls (중력식 옹벽에 작용하는 배면 동적 토력의 영향 인자 분석)

  • 윤석재;김성렬;김명모
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.09a
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    • pp.75-82
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    • 2002
  • The Mononobe-Okabe method is generally used to evaluate the dynamic earth force for the seismic design of retaining walls. However, the Mononobe-Okabe method does not consider the effects of the dynamic interactions between the backfill soil and the wall. In fact, a phase difference exists between the inertia force and the seismic earth pressure. In this study, shaking table tests were peformed on gravity walls retaining dry backfill sand to analyze the influence of several parameters (the unit weight of the wall, the input acceleration and base friction) on the development of the seismic earth pressure. The experiments revealed that the magnitude of the inertia force mobilized during seismic loading affected the seismic earth pressure. The difference in the phase angles between the inertia force and the seismic earth pressure was retained at 180 degrees before the wall failed but its magnitude changed significantly as the wall began to fail.

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The effects of learning strategies unit time based core achievement standard of science (과학과의 핵심성취기준에 근거한 단위시간 수업전략 효과)

  • Lee, Yong-Seob;Kim, Soon-Shik
    • Journal of the Korean Society of Earth Science Education
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    • v.7 no.2
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    • pp.169-179
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    • 2014
  • The purpose of this study is to research about the effects on improvement academic achievement of students based on the core learning standards of science. The researcher selected experimenter and started this study as a graduate student who is majoring in science education, experimenter chose to study 48 Sixth graders in elementary schools in B city for research group(24 students), Comparison group(24 students). The study was conducted from March to the end of July 2014. The teacher who is doing activity of professor in research group and the comparison group is science education specialist. Researcher and experimenter frequently exchange their opinions for control variables of teacher. The results are as follows. First, based on unit time strategies based on core achievement standards classes are effective in improving students' academic achievement. Elementary school teacher has difficulty in teaching for all subjects based on unit time strategies. Second, based on unit time strategies based on core achievement standards classes showed high level of satisfaction in perception of students. Thus it can be seen that teaching strategies of unit time based on the core achievement standards is effective to academic achievement improvement. The proposal for further study based on the results is as follows. First, research is needed to study the teaching methods that have practical and theoretical study time and lesson application opportunity for teaching strategies of curriculum unit time. Second, experimental studies that using strategies of unit time based on the core achievement standards are needed about learning method that can be applied in a variety of subjects.

Development and Application of the CPS Instructional Program for the Astronomy Section of Highschool Science (고등학교 과학 천문분야의 CPS수업프로그램 개발 및 적용)

  • Shin, Seon-Young;Kim, Soon-Shik;Choi, Gwang-Sun;Choi, Sung-Bong
    • Journal of the Korean Society of Earth Science Education
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    • v.4 no.2
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    • pp.108-115
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    • 2011
  • The purpose of this study was to develop and apply a creative problem-solving(CPS) program of instruction for earth science. After the earth science sections of high school science textbooks were analyzed, a theme of instruction was selected from the first-year unit 'the origin and evolution of the universe', and a CPS model of instruction. 32 high school sophomores and juniors who were the members of an astronomy club in the city of Gimhae, South Gyeongsang Province, participated in the program, and they took a test in scientific creative problem-solving skills before and after the experiment to grasp the effect of the program on their creative problem-solving skills. Besides, a survey was conducted to find out their awareness of the program. As a result of implementing the CPS program based on the CPS model of instructional for the unit 'the origin and evolution of the universe', the program turned out effective at boosting the scientific creative problem-solving skills of the students. To be specific, they made a significant progress in validity and scientificity, but that's not the case for elaboration and originality. When their awareness of the CPS program was checked, they expected the program to spark their interest in astronomy and be beneficial to the improvement of their creative problem-solving skills, but they didn't rate group activities high on the ground that the group activities weren't performed smoothly. The findings of the study suggest that the CPS instructional program for the unit 'the origin and evolution of the universe' based on the CPS model of instruction had a good effect on the improvement of the scientific creative problem-solving skills of the students.

Interference Probability Calculation of Frequency Sharing Between Non-Geostationary-Satellite Orbit Mobile Earth Station and Land Mobile Station (비정지궤도 위성이동지구국과 육상이동간의 주파수 공유에 따른 간섭 확률 계산)

  • 박지웅;최재훈;김희동
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.7
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    • pp.1807-1816
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    • 1998
  • The interference probability between non-geostationary-statellite orbit mobile station is calculated when the two systems are sharing the frquency band below 1 GHz. The probability density function of a mobile earth station(MES) is calculated based on the established propagation model and then, a probability of exceeding the threshold level is derived. By changing the average transimission per unit time of total MSS(Moblie satellite service) area and the ratio of transmitters for specific area, we obtain the average transmission per unit time for the area under consideration. From this, the exceedance probability for the given pfd threshold level is evaluated. The exceedance probability is increased as the average transmissio per unit time and ratio become larger. Also the effect of filter isolation between channels is accounted for.

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An Analysis the Contents Related to a Subject 'Earth and Moon' from Elementary Science Textbooks of the 2009 Revised Curriculum and 2015 Revised Curriculum ('지구와 달' 주제와 관련된 초등학교 2009 개정 과학교과서와 2015 개정 과학교과서 내용 분석)

  • Lim, Cheonghwan;Chae, Donghyun
    • Journal of the Korean Society of Earth Science Education
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    • v.11 no.3
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    • pp.237-243
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    • 2018
  • The purpose of this study is to analyze the contents related to a subject 'Earth and Mooon' from elementary science textbooks of the 2009 revised curriculum and elementary science textbooks of the 2015 revised curriculum. For the research, the team selected and analyzed the contents of the 'Earth and Moon' unit in the elementary science textbooks of the 2009 revised curriculum and 2015 revised curriculum. As a result of the research, first, there has been no significant change in achievement standards of the curriculum as the science textbook revised from 2009 curriculum to 2015 curriculum. Second, the two curriculum did not differ much in specific textbook contents statement or development, but they showed much change in presentation of exploration activities in curriculum as well as the specific exploration activities presented in the textbooks. Third, compared to science textbooks of the 2009 revision the 2015 revision used more pictures and illustrations. Forth, there have been few changes related to experimental observation, but the activities to organize the unit in 2015 revision have been strengthened compared to the 2009 revision.

Establishment of Guardrail Distance for Safety of Reinforced Earth Retaining Wall by Vehide Collision (차량충돌에 대한 보강토 옹벽 안전성 확보를 위한 가드레일 설치거리)

  • Park, Kwon;Hong, Ki-Nam;Ahn, Kwang-Kuk
    • Journal of the Korean Society of Safety
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    • v.24 no.5
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    • pp.57-62
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    • 2009
  • In this study, the numerical analyses regarding the distance between the guardrail and the reinforced earth wall as parameter were performed to determine the safe distance of guardrail installed on reinforced earth wall from the reinforced earth wall. The analyses were fulfilled by increasing the distance between the guardrail and reinforced earth wall from 150mm to 750mm. The computer program used in this research is LS-DYNA, which is very' popular in analysis of vehicle collision. Ford single unit truck in NCAC was employed as the model of vehicle and the velocity of vehicle collision was 80km/hr. As a results of analyses, the safety of guardrail was secured regardless of the distance between the guardrail and block of reinforced earth wall. However, to secure the safety of block of reinforced earth wall the distance between the guardrail and block of reinforced earth wall should be over 600mm.