• Title/Summary/Keyword: earth work

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Automated Image Receiving and Processing System for Landsat 7

  • Park, Sung-Og;Kim, Moon-Gyu;Kim, Tae-Jung;Ji-Hyeon, Shin;Choi, Myung-jin;Park, Jeong-Hyun
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.573-577
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    • 2002
  • The Landsat Program is the longest running enterprise for acquisition of imagery of the Earth from space. The first Landsat satellite was launched in 1972 and the most recent, Landsat 7, was launched on April 15, 1999. The Landsat satellites have acquired millions of images. The Landsat 7 receiving station is installed at more than 25 sites and will be installed in Korea. This paper will address the work being carried out for the development of image receiving and processing system for the Landsat 7 image data, which will be used at ground station of Landsat 7 in Korea.

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Remediation of Contaminated Groundwater: Change of Paradigm for Sustainable Use

  • Lee, Jin-Yong;Lee, Kang-Kun
    • Journal of Soil and Groundwater Environment
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    • v.18 no.6
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    • pp.1-7
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    • 2013
  • Groundwater development and use have been increasing in Korea causing frequent occurrences of related hazards such as groundwater level decline, land subsidence, and groundwater contamination. To tackle these groundwater problems, central and local governments have set-up and maintained many groundwater monitoring programs such as the National Groundwater Monitoring Network and the Groundwater Quality Monitoring Network, which collect very valuable data on the overall status of domestic groundwater to aid proper groundwater management. However, several problems mainly related to the remediation of contaminated groundwater remain unresolved. Recently, there have been some incidents related to the contamination of groundwater, and these have drawn the concern of the Korean people. Although groundwater contamination has been investigated in detail, actual groundwater remediation work has not yet been implemented. The remediation of the contaminated groundwater must begin immediately in order to sustain the eco-system service of clean groundwater and enhance the welfare of the Korean people.

Equivalent period and damping of SDOF systems for spectral response of the Japanese highway bridges code

  • Sanchez-Flores, Fernando;Igarashi, Akira
    • Earthquakes and Structures
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    • v.2 no.4
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    • pp.377-396
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    • 2011
  • In seismic design and structural assessment using the displacement-based approach, real structures are simplified into equivalent single-degree-of-freedom systems with equivalent properties, namely period and damping. In this work, equations for the optimal pair of equivalent properties are derived using statistical procedures on equivalent linearization and defined in terms of the ductility ratio and initial period of vibration. The modified Clough hysteretic model and 30 artificial accelerograms, compatible with the acceleration spectra for firm and soft soils, defined by the Japanese Design Specifications for Highway Bridges are used in the analysis. The results obtained with the proposed equations are verified and their limitations are discussed.

Research on Transition of Road Bed of Wuhan-Guangzhou Passenger Line and Bridge

  • Kang, Bo-Soon;Jun, Yang
    • International Journal of Railway
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    • v.2 no.4
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    • pp.180-186
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    • 2009
  • High speed railway challenge the design, construction and maintaining of traditional railway, many traditional design concepts have been changed. Transition of railway and bridge has two main problems. one is that different lines have different ability of resisting distortion in area of trial load, which was known that problem of smooth transition of stiffness, the other is that differential settlement between artificial structure and earth structure cause bending of railway. The two problems have effect on train moving. The principle of processing transition of railway and bridge is same in world, but it is difficult to find relationship between design standard of transition, vehicle performance, line standard, design speed and so on form documentation and data reports. Based on mechanics, the paper analyzed dynamic performance of transition of high speed railway, studied various rough elements which is effective to train moving, built mathematical model of interaction of train and transition of high speed railway and developed numerical simulation software. In various different work conditions, we did great quantity of numerical simulation, comprehensive analysis and performance analysis.

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The fire-risks of cost-optimized steel structures: Fire-resistant and hot-rolled carbon steel

  • Garcia, Harkaitz;Cuadrado, Jesus;Biezma, Maria V.;Calderon, Inigo
    • Structural Engineering and Mechanics
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    • v.78 no.1
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    • pp.67-75
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    • 2021
  • This work studies the behaviour of a steel portal frame selection under fire exposure, considering both span lengths and fire exposure times as variables. Such structures combine carbon steel (S275), fireproof micro-alloyed steel (FR), and coatings of intumescent paint with variable thicknesses, improving thereby the flame retardant behaviour of the steel structure. Thus, the main contribution of this study is the optimization of the portal frames by combining both steels, analysing the resulting costs influence on the final dimensions. Besides, the topological optimization of each steel component within the structure is also defined, in accordance with the following variables: weather conditions, span, paint thickness, and cost of steel. The results mainly confirmed that using both FR and S275 grades with intumescent painting is the Pareto optimum when considering performance, feasibility and costs of such portal frames widely used for industrial facilities.

Revised Geology and Geological Structures of the Northeastern Chungnam Basin in the Southwestern Korean Peninsula

  • Yujung Kwak;Seung-Ik Park;Jeong-Yeong Park;Taejin Choi;Eun Hye Jeong
    • Economic and Environmental Geology
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    • v.55 no.6
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    • pp.597-616
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    • 2022
  • The Chungnam basin is a crucial area for studying the Mesozoic crustal evolutionary history of the Korean Peninsula. This study reports the revised geology and new isotopic ages from the northeastern Chungnam Basin based on detailed geological mapping and LA-ICP-MS zircon U-Pb analysis. Our renewed geologic map defines intra-basin, basin-bounding, and basement fault systems closely related to hydrothermal gold-bearing quartz vein injections. Here, we propose the directions of (micro)structural and geochronological future work to address issues on the relationship between the tectonic process, basin evolution, and hydrothermal fluid migration in the southwestern Korean Peninsula.

Structural Stability Study on the Location and Installation form of H-beam Backfill Applied to Top-Down Construction Method (역타공법에 적용되는 뒷채움재 위치 및 설치 형태에 대한 구조 안정성 연구)

  • Shim, Hak-Bo;Jeon, Hyun-Soo;Seok, Won-Kyun;Park, Soon-Jeon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.179-179
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    • 2021
  • Top-Down construction method is a method of connecting a beam to a column and using a strut to support earth retaining walls. This method has the advantage of reducing the process of underground construction by reducing the work of installation. Recently, there are a lot of cases of damage and defect occurring in H-beam backfill applied to Top-Down construction method and the concrete slab supporting H-beam backfill. For this, appropriate methods were suggested through finite element analysis of the position and installation form of the H-beam backfill.

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Uncertainty Quantification of Thermophysical Property Measurement in Space and on Earth: A Study of Liquid Platinum Using Electrostatic Levitation

  • Jannatun Nawer;Takehiko Ishikawa;Hirohisa Oda;Chihiro Koyama;Douglas M. Matson
    • Journal of Astronomy and Space Sciences
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    • v.40 no.3
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    • pp.93-100
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    • 2023
  • A study of uncertainty analysis was conducted on four key thermophysical properties of molten Platinum using a noncontacting levitation technique. More specifically, this work demonstrates a detailed reporting of the uncertainties associated with the density, volumetric thermal expansion coefficient, surface tension and viscosity measurements at higher temperatures for a widely used refractory metal, Platinum using electrostatic levitation (ESL). The microgravity experiments were conducted using JAXA's Electrostatic Levitation Furnace (ELF) facility on the International Space Station and the terrestrial experiments were conducted using NASA's Marshal Space Flight Center's ESL facility. The performance of these two facilities were then quantified based on the measurement precision and accuracy using the metrological International Standards Organization's Guide to the Expression of Uncertainty Measurement (GUM) principles.

COVID-19 vaccines development in Africa: a review of current situation and existing challenges of vaccine production

  • Emmanuel Lamptey;Ephraim Kumi Senkyire;Dooshima Aki Benita;Evans Osei Boakye
    • Clinical and Experimental Vaccine Research
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    • v.11 no.1
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    • pp.82-88
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    • 2022
  • Following the development of the coronavirus disease 2019 (COVID-19) vaccines and the launching of vaccination, the World Health Organization has reported that the African Continent is lagging in the race to vaccinate its population against the deadly virus. The Continent has received a limited number of vaccines, implying that vaccine production needs to be scaled up in Africa. In this review, we summarize the current situation concerning COVID-19 vaccine development in Africa, progress made, challenges faced in vaccine development over the years and potential strategies that will harness vaccine production success.

The Analysis of planning methode and case study for Model 'Climate Change Adaptation City' (기후변화 적응도시 모델개발을 위한 계획기법 및 사례 분석)

  • Kim, Jongkon
    • KIEAE Journal
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    • v.12 no.4
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    • pp.13-19
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    • 2012
  • The Earth's surface temperature still continues to rise, and extreme weather phenomena such as heat waves, drought, and precipitation have been repeated every year. It is reported that international communities attribute the main cause of the Earth's surface temperature rise to the excessive use of the fossil energy. Recently, the damage caused by climate change is getting worse, and the place where we live is suffering the most. Cities have been continuously growing not only meeting the basic functions of human habitation, work and leisure but also being places for various economic and social activities. But Cities, the victims of climate change, have grown only considering human needs and convenience rather than predicting their physical and ecological systems(Albedo effects, urban microclimate, resources and energy of the circulatory system, etc). In other words, the cities offer the cause of the problems of climate change, and even worsen the extreme weather phenomena without coping with them. Therefore, it is urgent priorities to protect the climate, to prevent the causes of the extreme weather phenomena and to enhance the adaptive capacity for the worse weather events. This study is to derive the concept for adapting to these climate changes which can make cities escape from exposure to these climate change impacts and make themselves safer places to live. And it analyzes some European cities and present developing models to implement planning methods. In this study, the concept of the climate adaptive cities will be suggested to prepare the adaptation measures for urban planners, and climate change adaptation models will be presented by analyzing some preliminary cases.