• Title/Summary/Keyword: Earth Systems

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Design of Passive Treatment Systems for Mine Drainage Waters

  • Jeen, Sung-Wook
    • Journal of Soil and Groundwater Environment
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    • v.22 no.2
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    • pp.1-9
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    • 2017
  • Passive treatment systems are commonly used for remediation of mine drainage waters because they do not require continuous chemical inputs and operation. In this study, the selection and design criteria for such systems were evaluated, particularly the two most commonly used ones, i.e., permeable reactive barriers (PRBs) and vertical flow biological reactors (VFBRs). PRBs and VFBRs are operated on the same principles in terms of biochemical reaction mechanisms, whereas differences relate to configuration, engineering, and water management. In this study, each of these systems were described with respect to key design variables, such as metal removal mechanisms and removal rates, effectiveness and longevity, general design and construction, flow capacity, and cost. The information provided from this study could be used as a design guideline when a passive treatment option is considered for potential remediation of a mine site.

Current Development Status of Payload Data Handling Unit for Earth Observation Satellite (지구관측 위성용 탑재체자료처리장치 개발 동향)

  • Lee, Jong-Tae;Lee, Sang-Gyu;Yong, Sang-Soon;Yi, Ho-Sang;Lee, Seung-Kun;Song, Jin-Huan;Kwak, Sin-Ung
    • Current Industrial and Technological Trends in Aerospace
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    • v.9 no.1
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    • pp.90-101
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    • 2011
  • In this article, we introduce the technologies and trend of technical evolution of Payload Data Handling Unit (PDHU) for Earth Observation Satellites. As well, we review the efforts for the Koreanization of PDHU so far, and conclude with some suggestions for future work.

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Effects of Systems Thinking on High School Students' Science Self-Efficacy (시스템 사고가 고등학생의 과학 자기 효능감에 미치는 영향)

  • Lee, Hyundong;Lee, Hyonyong
    • Journal of the Korean earth science society
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    • v.37 no.3
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    • pp.173-185
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    • 2016
  • The purpose of this study is to investigate the effects of systems thinking on high school students' self-regulatory efficacy and self-confidence that constitute science self-efficacy. We set self-regulatory efficacy as a factor of students' systems thinking affects their self-confidence on science through self-regulatory efficacy. A total of 210 students were sampled from general high schools and 188 valid cases were analyzed. The instrument has 39 items that consist of 20 items measuring systems thinking and 19 items of science self-efficacy. The result of the exploratory factor analysis indicated that 20 items for systems thinking, 8 items for self-regulatory efficacy, 4 items for self-confidence are reasonable. Testing the goodness of fit of a structural equation model, it turn out to be appropriate (${\chi}^2$=344.498, df=242, TLI= .921, RMSEA= .044) using 24 items (mental model, personal mastery, systems analysis, self-regulatory efficacy, and self-confidence were constructed). In addition, the mental model, which is one factor of systems thinking, is mediated by self-regulatory efficacy that affects self-confidence directly and/or indirectly. The results suggest that systems thinking affects science self-efficacy directly and indirectly. Utilizing systems thinking in science education can produce a theoretical basis in improving students' confidence and self-efficacy about science.

Ocean tide-induced secular variation in the Earth-Moon dynamics

  • Uchida, Natsuki;Shima, Hiroyuki
    • Coupled systems mechanics
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    • v.7 no.5
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    • pp.611-626
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    • 2018
  • We theoretically consider a possible influence of periodic oceanic tides on non-periodic changes in the dynamics of the Earth and Moon over a long time scale. A particular emphasis will be placed on the contribution from rotating tidal waves, which rotate along the inner edge of an oceanic basin surrounded by topographic boundary. We formulate the angular momentum and the mechanical energy of the rotating tidal wave in terms of celestial parameters with regard to the Earth and Moon. The obtained formula are used to discuss how the energy dissipation in the rotating tidal wave should be relevant to the secular variation in the Earth's spin rotation and the Earth-Moon distance. We also discuss the applicability of the formula to general oceanic binary planets subject to tidal coupling.

Feasibility study on corrosion monitoring of a concrete column with central rebar using BOTDR

  • Sun, Yijie;Shi, Bin;Chen, Shen-En;Zhu, Honghu;Zhang, Dan;Lu, Yi
    • Smart Structures and Systems
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    • v.13 no.1
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    • pp.41-53
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    • 2014
  • Optical fiber Brillouin sensor in a coil winding setup is proposed in this paper to measure the expansion deformation of a concrete column with a central rebar subjected to accelerated corrosion. The optical sensor monitored the whole dynamic corrosion process from initial deformation to final cracking. Experimental results show that Brillouin Optical Time Domain Reflectometer (BOTDR) can accurately measure the strain values and identify the crack locations of the simulated reinforced concrete (RC) column. A theoretical model is used to calculate the RC corrosion expansive pressure and crack length. The results indicate that the measured strain and cracking history revealed the development of the steel bar corrosion inside the simulated RC column.

Visualization System for Earth Environmental Data Base

  • Ikoma, Eiji;Kitsuregawa, Masaru
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.280.1-285
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    • 1998
  • The earth's environmental problems have attracted serious attention worldwide. Various kinds of environmental data, such as remote sensing data, have become available for examining. Although this data is crucial to understanding such problems, there has become an over-abundance in variety of size, format, and filetype which makes it difficult for researchers to handle. We feel that earth environmental researchers should not be burdened by such cumbersome tasks. Therefore, we are developing a digital library for earth environmental information and a VRML based data visualization system for it. Even now, content-based image retrieval systems have many problems attributed to the degree of difficulty in implementing them. Thus, we are trying to visualize this data so that researchers can utilize it more efficiently, effectively, and easily. A great advantage for VRML users is that people can see environmental data from any perspective above the earth and with any resolution easily. Also by using MPEG-movie, users can observe the changes of data drawn from time series files.

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A study on the role and application technology of the space explorer (우주 탐사선에서 파일 시스템의 역할 및 응용 기술 연구)

  • Koo, Cheol-Hea;Ju, Gwang-Hyeok
    • Aerospace Engineering and Technology
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    • v.12 no.2
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    • pp.91-98
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    • 2013
  • Computing environment of space explorer including LEO (Low Earth Orbit), GEO (Geosynchronous Earth Orbit) satellite may be considered as the same category of embedded system on the ground. But with comparison with personal computing environment it is widely accepted that the space computing is outdated and behind of state of the art. Especially file system which is nearly essential item in all ground computing environment including personal computer, workstation and server is rarely used in space explorer till lately. In this paper, a study of ESA PUS (Packet Utilization Standard) and CCSDS (Consultative Committee for Space Data Systems) community's activity, international trend, and applicable technical application for applying file system in oder to use these standards for utilizing the file system to deep space explorer is described.

A Method and System to Compensate Vertical Component of 3-Dimensional Magnetic Field Sensor Using The Earth's Field (지구자계를 이용한 3축 자계센서의 수직성분자계 보정방법 및 장치)

  • Jung Young-Yoon;Lim Dae-Young;Ryoo Young-Jae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.16 no.3
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    • pp.297-302
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    • 2006
  • In this paper, a method and system to compensate vertical component of 3-dimensional magnetic field sensor using the earth's field was described. Output of magnetic field sensor have a output offset that is generated setting angle error of magnetic sensor and gain error. Thus, to using the magnetic field sensor, it must be compensated. The compensation of magnetic field sensor is required at shield space. However, using the earth's field, output offset of the sensor can be simply compensated. And, we designed system for compensation of the sensor. The proposed method and system are verified usefulness through experimental.