• Title/Summary/Keyword: Earth system model

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A Study on the Legislation Types and Prescriptions of American Earth Building Codes (미국 흙건축 법규의 법제화 유형 및 규제내용 분석)

  • Kim, Jeong-Gyu
    • KIEAE Journal
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    • v.8 no.3
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    • pp.19-26
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    • 2008
  • The purpose of this study is to analyze the legislation types and prescriptions of American earth building codes. The process of this study is as follows: (1) To understand the legislation background of American earth building codes, this study investigated the history and present state of earth building techniques which is used in USA. (2) To understand the legislation method and procedure of American earth building codes, this study investigated the legislation system of American building codes and the process of model building codes development and adoption. (3) To provide basic data for the legislation of Korean earth building codes or guidelines, this study analyzed American earth building codes about adobe, compressed earth block and rammed earth. The result of this study is as follows: (1) To meet need of a single coordinated set of national model building codes in the United States, the nation's three model code groups decided to form the International Code Council and the first edition of the International Building Code was published in 1997. In the International Building Code there are prescriptions on adobe construction. (2) There are three legislation types of earth building codes in USA. First is to use prescriptions of International Building Code on adobe construction. Second is that State governments establish and issue a separate document under its own title. The last is that local jurisdictions adopt International Building Code with amendments or additional rules. (3) On the base of analysis of American earth building codes, this study proposed the legislation process and direction of Korean earth building codes and guidelines.

A Study on the Earth's Variation Model to Adopt Ship's Digital Compass (선박용 디지털 컴퍼스에 적용하기 위한 지구편차 모형 개발)

  • Saha Rampadha;Yim Jeong-Bin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.06b
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    • pp.87-90
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    • 2006
  • The Earth's spherical harmonic model of the main field and of the secular variation, of the geomagnetic field gives the intensity and geomagnetic structure at any location around the earth, assuming an undistorted, steady state field that no external sources or localized earth anamalies. To consider the practical use of a ship's digital compass in earth's magnetic field, Earth's spherical harmonic model is searched for the related practical methods and procedures as a basic study in this work.

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Machine Learning-based Atmospheric Correction for Sentinel-2 Images Using 6SV2.1 and GK2A AOD (6SV2.1과 GK2A AOD를 이용한 기계학습 기반의 Sentinel-2 영상 대기보정)

  • Seoyeon Kim;Youjeong Youn;Jonggu Kang;Yemin Jeong;Soyeon Choi;Yungyo Im;Youngmin Seo;Chan-Won Park;Kyung-Do Lee;Sang-Il Na;Ho-Yong Ahn;Jae-Hyun Ryu;Yangwon Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.5_3
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    • pp.1061-1067
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    • 2023
  • In this letter, we simulated an atmospheric correction for Sentinel-2 images, of which spectral bands are similar to Compact Advanced Satellite 500-4 (CAS500-4). Using the second simulation of the satellite signal in the solar spectrum - vector (6SV)2.1 radiation transfer model and random forest (RF), a type of machine learning, we developed an RF-based atmospheric correction model to simulate 6SV2.1. As a result, the similarity between the reflectance calculated by 6SV2.1 and the reflectance predicted by the RF model was very high.

Prediction Skill of GloSea5 model for Stratospheric Polar Vortex Intensification Events (성층권 극소용돌이 강화사례에 대한 GloSea5의 예측성 진단)

  • Kim, Hera;Son, Seok-Woo;Song, Kanghyun;Kim, Sang-Wook;Kang, Hyun-Suk;Hyun, Yu-Kyung
    • Journal of the Korean earth science society
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    • v.39 no.3
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    • pp.211-227
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    • 2018
  • This study evaluates the prediction skills of stratospheric polar vortex intensification events (VIEs) in Global Seasonal Forecasting System (GloSea5) model, an operational subseasonal-to-seasonal (S2S) prediction model of Korea Meteorological Administration (KMA). The results show that the prediction limits of VIEs, diagnosed with anomaly correlation coefficient (ACC) and mean squared skill score (MSSS), are 13.6 days and 18.5 days, respectively. These prediction limits are mainly determined by the eddy error, especially the large-scale eddy phase error from the eddies with the zonal wavenumber 1. This might imply that better prediction skills for VIEs can be obtained by improving the model performance in simulating the phase of planetary scale eddy. The stratospheric prediction skills, on the other hand, tend to not affect the tropospheric prediction skills in the analyzed cases. This result may indicate that stratosphere-troposphere dynamic coupling associated with VIEs might not be well predicted by GloSea5 model. However, it is possible that the coupling process, even if well predicted by the model, cannot be recognized by monotonic analyses, because intrinsic modes in the troposphere often have larger variability compared to the stratospheric impact.

Earth Pressure Acting on the Model Wall due to Repeating Surcharge Load(I) (반복상재하중에 의해 모형벽체에 작용하는 토압(I))

  • Chon, Yong-Baek
    • Journal of the Korean Society of Industry Convergence
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    • v.5 no.1
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    • pp.65-74
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    • 2002
  • This paper intends to investigate such effects through experiments. The contents of the investigation are effects of position of repeated loading and unloading, passing frequency. For the purpose of the investigation an experimental load-deflection system is developed and the system is possible to measure deflection of the wall and earth pressure due to different size of strip loading and cyclic loading. The findings from the experiments are as follows: 1. As repeated loading approaches to the wall, the measured horizontal residual earth pressure agrees well with Rowe's empirical formula, while as the loading is far from the wall the earth pressure consists with Boussinesq's and Spangler's formulas. Also it is found that below 0.6m depth from ground surface the effects of repeated loading can be nearly neglected. 2. From comparison analyses of earth pressure theories and experimental results, a reagression equation is suggested herein, and earth pressure at any depth and maximum earth pressure due to cyclic loading can be estimated from the equation.

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Determination of Multilayer Earth Model Using Genetic Algorithm

  • Kang, Min-Jae;Boo, Chang-Jin;Kim, Ho-Chan
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.7 no.3
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    • pp.171-175
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    • 2007
  • In this paper a methodology has been proposed to compute the parameters of the multilayer earth model using a genetic algorithm(GA). The results provided by the GA constitute the indispensable data that can be used in circuital or field simulations of grounding systems. This methodology allows to proceed toward a very efficient simulation of the grounding system and an accurate calculation of potential on the ground's surface. The sets of soil resistivity used for GA are measured in Jeju area.

Detection of Active Fire Objects from Drone Images Using YOLOv7x Model (드론영상과 YOLOv7x 모델을 이용한 활성산불 객체탐지)

  • Park, Ganghyun;Kang, Jonggu;Choi, Soyeon;Youn, Youjeong;Kim, Geunah;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.38 no.6_2
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    • pp.1737-1741
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    • 2022
  • Active fire monitoring using high-resolution drone images and deep learning technologies is now an initial stage and requires various approaches for research and development. This letter examined the detection of active fire objects using You Look Only Once Version 7 (YOLOv7), a state-of-the-art (SOTA) model that has rarely been used in fire detection with drone images. Our experiments showed a better performance than the previous works in terms of multiple quantitative measures. The proposed method can be applied to continuous monitoring of wide areas, with an integration of additional development of new technologies.

Future Change Using the CMIP5 MME and Best Models: I. Near and Long Term Future Change of Temperature and Precipitation over East Asia (CMIP5 MME와 Best 모델의 비교를 통해 살펴본 미래전망: I. 동아시아 기온과 강수의 단기 및 장기 미래전망)

  • Moon, Hyejin;Kim, Byeong-Hee;Oh, Hyoeun;Lee, June-Yi;Ha, Kyung-Ja
    • Atmosphere
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    • v.24 no.3
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    • pp.403-417
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    • 2014
  • Future changes in seasonal mean temperature and precipitation over East Asia under anthropogenic global warming are investigated by comparing the historical run for 1979~2005 and the Representative Concentration Pathway (RCP) 4.5 run for 2006~2100 with 20 coupled models which participated in the phase five of Coupled Model Inter-comparison Project (CMIP5). Although an increase in future temperature over the East Asian monsoon region has been commonly accepted, the prediction of future precipitation under global warming still has considerable uncertainties with a large inter-model spread. Thus, we select best five models, based on the evaluation of models' performance in present climate for boreal summer and winter seasons, to reduce uncertainties in future projection. Overall, the CMIP5 models better simulate climatological temperature and precipitation over East Asia than the phase 3 of CMIP and the five best models' multi-model ensemble (B5MME) has better performance than all 20 models' multi-model ensemble (MME). Under anthropogenic global warming, significant increases are expected in both temperature and land-ocean thermal contrast over the entire East Asia region during both seasons for near and long term future. The contrast of future precipitation in winter between land and ocean will decrease over East Asia whereas that in summer particularly over the Korean Peninsula, associated with the Changma, will increase. Taking into account model validation and uncertainty estimation, this study has made an effort on providing a more reliable range of future change for temperature and precipitation particularly over the Korean Peninsula than previous studies.

The Comparative Experiment of Geogrid Reinforcement Types with Construction Stage on Segmental Retaining Walls (블록식 보강토 옹벽에서의 시공단계별 보강재 타입에 따른 거동비교)

  • Lee, Sung-Hyouk;Lee, Jin-Wook;Choi, Chan-Yong
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.4
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    • pp.1-8
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    • 2012
  • In this study, the earth pressure, displacement and strain were compared with reinforcement types at segmental retaining wall through full scale model test. The test results found that the measurement of earth pressure and displacement at wall for the fully reinforced retaining wall are different from those for the partly reinforced retaining wall. The analyses of these results would suggest that the used of geoogrid allowed the vertical earth pressure and displacement at wall to be reduced. The horizontal earth pressure in upper and lower part of wall can change with reinforcement type and earth deformation and were larger than the active and the rest pressure. Also, the lateral earth pressure and displacement of wall have a very high a correlation. It was found that the strain contour distribution of reinforcements was occurred a large strain at cental part of wall in segmental retaining wall system.

Effect of Joint Spacing on the Earth Pressure Against the Support System in a Jointed Rock Mass

  • Son, Moorak;Adedokun, Solomon
    • Journal of the Korean GEO-environmental Society
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    • v.17 no.1
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    • pp.29-37
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    • 2016
  • This study examined the magnitude and distribution of earth pressure on the support system in a jointed rock mass due to the different joint spacing as well as varying the rock type and joint condition (joint shear strength and joint inclination angle). Based on a physical model test and its numerical simulation, a series of numerical parametric analyses were conducted using a discrete element method. The results showed that the magnitude and distribution of earth pressure were strongly affected by the different joint spacing as well as the rock type and joint condition. In addition, the study results were compared with Peck's earth pressure for soil ground, which indicated that the earth pressure in a jointed rock mass could be considerably different from that in soil ground. The study suggests that the joint spacing as well as the rock type and joint condition are important factors affecting the earth pressure in a jointed rock mass and they should be considered when designing a support system in a jointed rock mass.