• Title/Summary/Keyword: 지구와 달

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Study of seismic wave propagation around tunnel (터널 주위의 탄성파 전파양상에 관한 연구)

  • Suh, Baek-Su;Oh, Seok-Hoon;Shon, Kwon-Ik;Lee, Sang-Chul
    • 한국지구물리탐사학회:학술대회논문집
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    • 2006.06a
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    • pp.291-296
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    • 2006
  • The aspect of wave propagation around cavity was investigated for the exact inversion of crosshole tomography data in order to understand the possibility of the existence of underground cavity. We found that the adequate frequency range for the tunnel investigation was about 2kHz to 5kHz, and the grid space was set up to 1/10 length of wavelength. The propagation of the seismic wave near the cavity may go through or detour the cavity according to the seismic velocity of inside of cavity. The detouring wave propagates with the seismic velocity of mother rock in spite of the velocity of inside of cavity. The smaller the velocity difference between the mother rock and cavity, the more frequent penetration of the seismic wave through the cavity was appeared.

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A Critical Approach to an Elementary Science Lesson Using a Digital Science Textbook (디지털 교과서를 활용한 초등 과학 수업에 대한 비평적 접근)

  • Lim, Heejun;Oh, Phil Seok
    • Journal of Science Education
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    • v.38 no.2
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    • pp.270-285
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    • 2014
  • The purpose of this study was to explore what a science lesson using a digital textbook looked like and what kinds of implications could be drawn from the lesson. The study qualitatively described a 4th grade science lesson in the unit of Earth and Moon, analyzed the structure of the lesson, and critically interpreted the meaning of it. It was revealed that the introduction of a digital science textbook did not bring about changes in the already patternized structure of elementary science instruction as well as in the manner of classroom interaction. The result was followed by discussion concerning the ways the use of a digital textbook could change elementary science instruction and enable new types of classroom interaction. It was suggested that negotiations should be reached about the nature of digital science textbooks and their developments and that the teacher's own pedagogical roles in the science classroom should be improved.

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The Effects of the Pre-learning Program Applied by ICT-based TGT (Teams-Games-Tournaments) Cooperative Module for Science Museum Excursion Regarding of the Earth and the Moon on the Science Related Attitude according to Gender (지구와 달 관련 과학관 체험 학습에서 ICT 활용 협동 학습(TGT) 모듈을 적용한 사전 학습 프로그램이 성별에 따라 과학 관련 태도에 미치는 효과)

  • Park, Sun-Heung;Shin, Young-Joon
    • Journal of Korean Elementary Science Education
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    • v.29 no.3
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    • pp.326-340
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    • 2010
  • TGT (teams-games-tournaments) cooperative learning is suggested as a method which enables both the individualized teaching-learning and the small group learning in students-centered open education. This study investigated the instructional effects of the pre-learning program applied by ICT-based TGT cooperative module for science museum excursion regarding of the earth and the moon on the science related attitude according to gender difference in elementary school science class. Three classes of third graders (N=87) at a elementary school were randomly assigned to the ICT-based TGT cooperative learning group, the ICT learning group, and traditional learning group. The students were taught about the planning of exploring the moon in the chapter of the earth and the moon, for 1 class hour. Prior to the instructions, the TOSRA(test of science related attitude) and achievement test were administered. Two-way ANCOVA results revealed that the scores of the ICT-based TGT cooperative learning group were significantly higher than the other learning groups for most of the TOSRA scales. However, there was a little significant difference among the three groups in the three distinct scales of TOSRA, Normality of Scientists, Leisure Interest in Science, and Career Interest in Science. Advantage/disadvantage and usefulness of ICT-based TGT cooperative learning were also discussed.

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Elementary School 5th Students' Understanding of the Illustrations on the Phase change of the Moon in Science Textbook of 2007 and 2009 Revised National Curriculum (2007과 2009 개정 과학교과서에 제시된 달의 위상 변화 삽화에 대한 초등학교 5학년 학생들의 이해)

  • Yang, Il-Ho;Kim, Jung-Yun;Lim, Sung-Man
    • Journal of the Korean Society of Earth Science Education
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    • v.8 no.1
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    • pp.56-65
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    • 2015
  • The purpose of this study is to investigate how elementary school student understands or students understand the illustrations on the phase change of the Moon in science textbook and to find out how textbook illustration helps students form the conception of the phase change of the Moon. To identify this purpose, we selected illustrations on the phase change of the Moon in the science textbook revised in 2007 and 2009 revised science textbook. For this study we selected and interviewed 20 students in the fifth grade. We integrated all data collected through interviews and created a transcription and a protocol and then, confirmed scientific conceptions related to the phase change of the Moon in students' illustration reading. The result are as followings: First, students read more scientific conceptions related to the phase change of the Moon in illustration of the 2009 revised science textbook which is presented with the universal observer's view point and the earth observer's view point. Second, students who find meaning in the various elements of the illustration and interpret with the integration of the various elements, get a lot of relevant information from illustration. All students have no differences recognizing the elements presented in illustration. But there are differences of contents of illustration reading depending on how students interpret the illustrations with integration of the various elements and if students cannot figure out the four scientific concepts needed to understand the phase change of the Moon, they ignore the information provided by illustration or analysis in their own way according to information provided by illustration. So misconception appears in this process.

Analysis of Educational Effects in Augmented Reality Combined Marker System (증강현실 조합형 마커시스템의 교육효과분석)

  • Ko, Youngnam;Kim, Chongwoo
    • Journal of The Korean Association of Information Education
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    • v.16 no.3
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    • pp.373-382
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    • 2012
  • Of computing skills in the field of multi-media, particularly augmented reality technology contents may provide realistic learning experiences with 3D pictures through the learners' manipulation activities. However, the marker systems in the existing studies were not well developed as to maintain the students' interest and concentration. In this study, we have designed the first lesson ("Earth and Moon") of 5th graders' science with augmented reality combined system so that we could deal with manipulation activities of the relationship between augmented objects, From the experimental study, using combined augmented reality contents made a significant difference in their learning achievement and motivation. Thus augmented reality combined system can be utilized for a variety of topics to maintain students' learning motivation.

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Application of Geophysical Exploration Methods to Seepage Bone Investigation of Dam Structures (제방누수조사에의 물리탐사기법의 활용(쌍극자배열 전기비저항탐사와 SP탐사를 중심으로))

  • Won Jong-Geun;Song Sung-Ho
    • 한국지구물리탐사학회:학술대회논문집
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    • 1999.08a
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    • pp.240-257
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    • 1999
  • More than 16 percent of the total 18,032 reservoirs over the country were reported to have leakage problems and need to be improved. Recently, a great deal of progress was made in geophysical survey techniques, particularly in electrical resistivity, and the techniques are used for variety of Purposes in groundwater and dam management due to its economical advantages. This document describes the re-evaluation of existing resistivity data including newly surveyed data, mapping of modeled value in 2-D analysis to locate seepage pathways, This contains also discussion results of more than eighteen years of professional experiences in the field of dam efficiency improvement. In comparison of surface resistivity data with several soil analysis data in laboratory, it is evident that the surface resistivity value shows a qualitative proportionality with the sand contents of the filling materials in earth dam. The result from the study also indicates that the SP method in subsurface investigation is effective to detect seepage in earth filled dam as well as piping through rock/earthfill dike.

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Geotechnical Exploration Technologies for Space Planet Mineral Resources Exploration (우주 행성 광물 자원 탐사를 위한 지반 탐사 기술)

  • Ryu, Geun-U;Ryu, Byung-Hyun
    • Journal of the Korean Geotechnical Society
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    • v.38 no.9
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    • pp.19-33
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    • 2022
  • Planarity geotechnical exploration missions were actively performed during the 1970s and there was a period of decline from the 1 990s to the 2000s because of budget. However, exploring space resources is essential to prepare for the depletion of Earth's resources in the future and explore resources abundant in space but scarce on Earth, such as rare earth and helium-3. Additionally, the development of space technology has become the driving force of future industry development. The competition among developed countries for exoplanet exploration has recently accelerated for the exploration and utilization of space resources. For these missions and resource exploration/mining, geotechnical exploration is required. There have been several missions to explore exoplanet ground, including the Moon, Mars, and asteroids. There are Apollo, LUNA, and Chang'E missions for exploration of the Moon. The Mars missions included Viking, Spirit/Opportunity, Phoenix, and Perseverance missions, and the asteroid missions included the Hayabusa missions. In this study, space planetary mineral resource exploration technologies are explained, and the future technological tasks of Korea are described.

Unsteady Free Convection Flow in Horizontal Channels with Arbitrary Wall Temperatures (임의의 벽면온도에 따른 수평채널에서의 비정상 자연대류운동)

  • Im, Goeng
    • The Journal of Engineering Research
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    • v.1 no.1
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    • pp.23-30
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    • 1997
  • Energy transfer by free convection arises in many engineering applications, such as a hot steam radiator for heating a room, refrigeration coils, electric transformers, heating elements and electronic equipments. Generally unsteady natural convection flow in a horizontal channel with arbitrary wall temperatures and the mathematical and physical basis of convection transport has been considered in general. A physically meaningful exact solution of the problem has been obtained in a closed form by the application of the standard finite sine transform technique. Influences of the governing parameters, the Prandtl number and the Rayleigh number, to bring the flow and heat transfer to final steady states have been discussed separately. For constant values of the arbitray wall temperatures and of the function, determining the average axial velocity, the final steady state is approached in different times respectively for the cases when the Prandtl number Pr>1 and Pr<1. It is also seen that the function, representing the axial temperature gradient, is influenced by none of the governing parameters : but the steady state flow is influenced only by the Rayleigh number. There are, of course, many applications. Free convection strongly influences heat transfer from pipes and transmission lines, as well as from various electronic devices. It is also relevant to the environmental sciences, where it is responsible for oceanic and atmospheric motions, as well as related heat transfer processes.

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Degradation Monitoring of Visible Channel Detectors on COMS MI Using Moon Observation Images (달 관측 영상을 이용한 천리안위성 기상탑재체 가시채널 검출기의 성능감쇄 분석)

  • Seo, Seok-Bae;Jin, Kyoung-Wook
    • Korean Journal of Remote Sensing
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    • v.29 no.1
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    • pp.115-121
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    • 2013
  • The first geostationary satellite in Korea, COMS (Communication, Ocean, and Meteorological Satellite), has been operating properly since its successful completion of the IOT (In Orbit Test). COMS MI (Meteorological Imager) acquires Earth observation images from visible and infrared channels. This paper describes a method to compute the degradation of the COMS visible detectors and the result of the degradation during the two years of the operation. The visible channel detectors' performance was determined based on the comparison between the instrument-based measurements and ROLO model-based values. The degradation rate of the visible channel detectors of COMS MI showed a normal condition.

Brief Note On The Radio Navigation Systems In The Sea Around Korea (한국근해에서의 전파항법 적용에 관한 고찰)

  • Song, Moo Young
    • 한국해양학회지
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    • v.14 no.2
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    • pp.78-85
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    • 1979
  • Korea has not any fixed station for Radio Navigation systems yet. In some part of the Korean Sea, however, Japanese stations can be utilized for the Radio Navigation. 3 Decca chains were proposed to install the Decca Navigation network for Korea. Only for the coverage area, 1 Decca chain is sufficient for the sea around Korea instead of 3 chains. At present, Omega system is the most recommendable for the positioning in the farther area. In nearshore area, Raydist or Decca Trisponder is is useful for obtaining the position with high accuracy.

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