• Title/Summary/Keyword: the earth

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Development of Multimedia Database for Earth Science Learning (지구과학 학습을 위한 멀티미디어 학습 자료 데이터베이스 개발)

  • Lee, Won-Kook;Kim, Yeo-Sang;Kim, Chil-Young;Kim, Jong-Hun;Kim, Hee-Soo
    • Journal of the Korean earth science society
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    • v.21 no.2
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    • pp.116-127
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    • 2000
  • This study is aimed at the development of multimedia learning program for earth science in the middle and high school. This program was made of HTML format and includes a variety of texts, graphs, pictures, drawings, animations, and moving image materials. And it was composed of six database elements(learning context, terminology dictionary, practical science, inquiry actvity, image material, and test item). The results of applying this program to students and teachers gave affirmative answers. The program is being offered on an internet website under Institute of Science Education of Kongju National University.

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Perceptions on Earth Scientists' Workings of High School Students (지구과학자가 하는 일에 대한 고등학생들의 인식)

  • Cheong, Cheol;Kim, Yun-Ji
    • Journal of the Korean Society of Earth Science Education
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    • v.9 no.3
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    • pp.243-254
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    • 2016
  • This study investigated that internalized images of earth scientist's work of 110 high school students who complete a course in Earth Science I through drawing. As a result that reflected the character of earth science as a school subject, it is shown that nearly half of the students believe that earth scientist's working place is outside. An object of study is limited to such areas as astronomy and geology, it says that students has little understanding of areas of atmospheric and oceanic sciences. There are lots of answers that tools for working are telescope or microscope, it reveals a huge difference between the results of advanced research that analyzed the typical experimental devices, and students realized that working is not invention but survey. We should try students to recognize earth scientist as a job with relation to their future.

Study of seismic performance of super long-span partially earth-anchored cable-stayed bridges

  • Zhang, Xin-Jun;Yu, Cong;Zhao, Jun-Jie
    • Structural Engineering and Mechanics
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    • v.72 no.1
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    • pp.99-111
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    • 2019
  • To investigate the seismic performance of long-span partially earth-anchored cable-stayed bridge, a super long-span partially earth-anchored cable-stayed bridge scheme with main span of 1400m is taken as example, structural response of the bridge under E1 seismic action is investigated numerically by the multimode seismic response spectrum and time-history analysis, seismic behavior and also the effect of structural geometric nonlinearity on the seismic responses of super long-span partially earth-anchored cable-stayed bridges are revealed. The seismic responses are also compared to those of a fully self-anchored cable-stayed bridge with the same main span. The effects of structural parameters including the earth-anchored girder length, the girder width, the girder depth, the tower height to span ratio, the inclination of earth-anchored cables, the installation of auxiliary piers in the side spans and the connection between tower and girder on the seismic responses of partially ground-anchored cable-stayed bridges are investigated, and their reasonable values are also discussed in combination with static performance and structural stability. The results show that the horizontal seismic excitation produces significant seismic responses of the girder and tower, the seismic responses of the towers are greater than those of the girder, and thus the tower becomes the key structural member of seismic design, and more attentions should be paid to seismic design of these sections including the tower bottom, the tower and girder at the junction of tower and girder, the girder at the auxiliary piers in side spans; structural geometric nonlinearity has significant influence on the seismic responses of the bridge, and thus the nonlinear time history analysis is proposed to predict the seismic responses of super long-span partially earth-anchored cable-stayed bridges; as compared to the fully self-anchored cable-stayed bridge with the same main span, several stay cables in the side spans are changed to be earth-anchored, structural stiffness and natural frequency are both increased, the seismic responses of the towers and the longitudinal displacement of the girder are significantly reduced, structural seismic performance is improved, and therefore the partially earth-anchored cable-stayed bridge provides an ideal structural solution for super long-span cable-stayed bridges with kilometer-scale main span; under the case that the ratio of earth-anchored girder length to span is about 0.3, the wider and higher girder is employed, the tower height-to-span ratio is about 0.2, the larger inclination is set for the earth-anchored cables, 1 to 2 auxiliary piers are installed in each of the side spans and the fully floating system is employed, better overall structural performance is achieved for long-span partially earth-anchored cable-stayed bridges.

A Study on Design of Metadata for Global Earth Observation Data (지구관측자료 메타데이터 설계에 관한 연구)

  • Ahn, Bu-Young;Han, Jeong-Min;Kwon, Oh-Kyoung;Joh, Min-Su
    • Journal of Information Management
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    • v.39 no.2
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    • pp.211-234
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    • 2008
  • Recently, the frequency and scale of natural disasters such as typhoons, flood, earthquakes, and tidal waves from earthquakes has been increasing. Several nations have recognized that earth observation is essential for protecting the Earth's environment. However, as the data format from earth observation varies depending on areas, institutes, and countries, sharing and exchange between data is difficult. Thus, we have a metadata standardization scheme suitable for the domestic situation to allow exchange of data between societal benefit areas with reference to principles of data sharing and exchange that are discussed on GEO (Group on Earth Observation). We have also designed metadata schemes required to identify the metadata situation of earth observation data being used for 9 societal benefit areas of GEOSS(Global Earth Observation System of Systems).

A Case Study of Service Education Activities Applying Mathematics into a Place-Based Earth Science Program: Measuring the Earth's Size (수학과 연계한 장소기반 지구과학 프로그램에 대한 교육봉사활동 사례 연구: 지구의 크기 측정)

  • Yu, Eun-Jeong;Kim, Kyung Hwa
    • Journal of the Korean earth science society
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    • v.40 no.5
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    • pp.518-537
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    • 2019
  • This study examined the implications of a place-based earth science program integrated with Mathematics. 11 pre-service earth science teachers and 22 middle school students participated in the service education activities of earth science for 30 hours focusing on the measurement of the earth's size through earth science experiments as part of the middle school curriculum. In order to minimize errors that may occur during the earth's size measurement experiments using Eratosthenes's shadows length method of the ancient Greek era, the actual data were collected after triangulation ratios were conducted in the locations of two middle schools: one in remote metropolitan and the other in rural area. The two schools' students shared the final estimate result. Through this process, they learned the mathematical method to express the actual data effectively. Participants, experienced the importance and difficulty of the repetitive and accurate data acquisition process, and also discussed the causes of errors included in the final results. It implies that a Place-Based Earth Science Program activity can contribute to students' increased-understanding of the characteristics of earth science inquiry and to developing their problem solving skills, thinking ability, and communication skills as well, which are commonly emphasized in science and mathematics in the 2015 reunion curriculum. It is expected that a place-based science program can provide a foundation for developing an integrated curriculum of mathematics and science.

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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Analysis on New Research Opportunities and Strategies for Earth Sciences in the United States (미국 지질과학분야 신규 연구주제 및 전략분석)

  • Kim, Seong-Yong;Ahn, Eun-Young;Bae, Jun-Hee;Lee, Jae-Wook
    • Economic and Environmental Geology
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    • v.49 no.1
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    • pp.43-52
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    • 2016
  • The essential role of the Division of Earth Sciences(EAR) in the Directorate of Geoscience(GEO) of National Science Foundation of America(NSF) is to support basic research aimed at acquiring fundamental knowledge of the Earth system that can be directly applied to the United States' strategic needs. The 2011 Committee on New Research Opportunities in the Earth Sciences(NROES) of the National Academy of Sciences(NAS) identified specific areas of the basic earth science research scope of the EAR that were poised for rapid progress during the next decade. Quantified by interdisciplinary approaches, the Committee highlighted the following topics relating to the EAR Deep Earth Processes and Surface Earth Processes sections: (1) the early Earth; (2) thermochemical internal dynamics and volatile distribution; (3) faulting and deformation processes; (4) interactions among climate, the Earth surface processes, tectonics, and deep Earth processes; (5) co-evolution of life, environment, and climate; (6) coupled hydrogeomorphic-ecosystem response to natural and anthropogenic change; and (7) interactions of biogeochemical and water cycles in terrestrial environments. We also promote future research challenges such as the critical zone studies. In order to promote more active such a huge future research challenges, additional research support policies are needed.

Stability and Earth Pressure Distribution of Excavated Earth Retaining Wall by Centrifugal Model Tests (원심모형실험에 의한 굴착 흙막이벽의 안정 및 토압분포)

  • Kim, Y.C.;Lee, C.K.;Kim, H.J.;Ahn, K.K.;Lee, M.W.;Heo, Y.
    • Journal of the Korean Society of Safety
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    • v.12 no.3
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    • pp.139-146
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    • 1997
  • In this study, centrifugal model tests were performed to investigate the behavior of excavated earth retaining wall with the depth of excavation and different types of wall(aluminum, steel panel). Jumunjin standard sand was used for foundation soil. The raining method was adopted to form the required relative density of the model ground. The lateral earth pressure measured from tests were compared with estimated active earth pressure by Rankine's theory. The test results have shown that the earth pressure acting on the retaining wall and the rotation displacement of the wall are influenced by the depth of excavation and the type of wall. It was found from the test results that the deformation of the wall increases with the depth of excavation.

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Analyzing Causes of Seasonal Changes Displayed by Primary Teachers at the Equator

  • Chae, Dong-Hyun
    • Journal of The Korean Association For Science Education
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    • v.29 no.7
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    • pp.759-766
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    • 2009
  • This study was conducted to examine 10 Belizean teachers' conceptions about the causes of seasonal change. This research was conducted with an integrated method using a open ended written test and an interview which included a drawing. There are four categories, explained by the teachers, as the causes of seasonal changes. They are; climate, rotation of the earth on its axis, revolution of the earth around the sun, and the tilting of earth's axis as it revolves. Most teachers misunderstood that the first of three categories was responsible for seasonal change. Second, it is more effective to use the integrated method shown in this research than to use only a written test when seriously investigating the causes and understanding of seasonal change. Third, 8 out of 10 teachers could not correctly explain the causes of seasonal change. The reasons for seasonal change seemed to be hard for the informants to understand even though it was taught in elementary, middle, high school, and college elective classes.

SOLAR ACTIVITY AND SPACE ENVIRONMENT (태양활동과 우주환경)

  • YUN HONG SIK
    • Publications of The Korean Astronomical Society
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    • v.14 no.2
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    • pp.83-89
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    • 1999
  • The Earth is exposed to constant outflow of the solar wind from the outer layers of the Sun, and violent transient events taking place from active regions increase the energy flux of both radiation and particles leaving the Sun. Thus the space surrounding the Earth is a highly dynamic environment that responds sensitively to changes in radiation, particles and magnetic field arriving from the Sun. Nowadays, it becomes increasingly important to understand how the physical system of Earth-space works and how the space around the Earth connects to interplanetary space. In the present paper we describe how explosive solar events, such as CME(Coronal Mass Ejection) and flares affect the Earth-space environment and how the space weather reacts to them. Practical consequences are presented to demonstrate why a broader view of Earth's environment is greatly needed to cope with modern day's inhabitation problem in a rapidly developing space age.

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