• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.11
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• pp.57-64
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• 2005

Large Eddy Simulation (LES) of turbulent premixed combustion flow is performed by using the dynamic subgrid scale model based on -equation describing the flame front propagation. After introducing the LES governing equations with dynamic subgrid scale (DSGS) model newly introduced into the -equation, the turbulent premixed combustion flow over backward facing step is analyzed to validate present formulation. The calculated results can predict the velocity and temperature of the combustion flow in good agreement with the experiment data.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.1
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• pp.93-97
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• 2012

Agricultural water reservoirs upstream of the intake on the basis of the intaking water volume is being made. Therefore, the supply capacity of reservoirs are not considered when the water balance analysis, storm water reservoirs are based on agriculture and further secured by the reservoir water is not used to using natural river water analysis. To overcome these problems can supply reservoirs are available to permit analysis of how much the quantity of water balance analysis, it should be reflected in the line to help. In this study, the natural daily flow data and apply the dimensions of the reservoir, and for more than 30 years of the long-term water balance analysis conducted by Date Youngsan river basin can supply reservoirs are large quantity of permits available is presented.

• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.106-109
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• 2006

A large eddy simulation with explicit filters on unstructured mesh is presented. Two explicit filters are adopted for reducing the aliasing error of the nonlinear convective term and measuring the level of subgrid scale velocity fluctuation, respectively. The developed subgrid scale model is basically eddy viscosity model which depends on the explicitly filtered fields and needs no additional ad hoc wall treatment such as van Driest damping function. As a validation problem, the flows around a sphere at several Reynolds numbers, including laminar and turbulent regimes, are calculated and compared to experimental data and numerical results in the literature.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.974-987
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• 2021

This paper presents ductile fracture simulation of full-scale cracked pipe for nuclear piping materials using the cohesive zone model (CZM). The main objective of this study is to investigate the applicability of CZM to predict ductile fracture of cracked pipes with various crack shapes and under quasi-static/dynamic loadings. The transferability of the traction-separation (T-S) curve from a small-scale specimen to a full-scale pipe is demonstrated by simulating small- and full-scale tests. T-S curves are calibrated by comparing experimental data of compact tension specimens with finite element analysis results. The calibrated T-S curves are utilized to predict the fracture behavior of cracked pipes. Three types of full-scale pipe tests are considered: pipe with circumferential through-wall crack under quasistatic/dynamic loadings, and with 360° internal surface crack under quasi-static loading. Computational results using the calibrated T-S curves show a good agreement with experimental data, demonstrating the transferability of the T-S curves from small-scale specimen.

• Journal of the Korean Operations Research and Management Science Society
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• v.5 no.1
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• pp.89-90
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• 1980

원래 다량자료의 정리(Large Scale Data Screening)는 어떤 정립된 이론에 의해 수행되는 것보다는 그 자료자체가 가지는 성격과 자원의 Availability 등을 고려하여 수행되는 것이 상례이다. 여기서는 여러 방법 중 자료가 모두 수치로 나타나는 경우 자료정리의 한 유용한 방법으로 회귀분석을 사용하는 방법에 대해 설명코자 한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.705-708
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• 2004

The spatial variability of the L- and C- band large scale remotely sensed soil moisture data, obtained during tire Southern Great Plain 1999 (SGP'99), was characterized. The results demonstrate that soil moisture data using L-band show the break in statistical symmetry (multiscaling behavior) with the variation of scale of observation, which is similar to that of the soil property such as sand content. Also, soil moisture data using C-band show single scaling behavior with the variation of scale of observation, which Is similar to that of the vegetation condition.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.499-502
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• 2015

Starburst galaxies have strong star formation activity and generate large scale outflows which eject a huge amount of gas mass. This process affects galaxy activity, and therefore, the detailed study of nearby starburst galaxies could provide valuable information for the study of distant ones. So far there have been only a few studies of galactic-scale molecular outflows due to the sensitivity limitation of telescopes. Our study provides two nearby examples, NGC 2146 and NGC 3628. We used Nobeyama Millimeter Array (NMA) CO(1-0) data, Chandra soft X-ray data, and NMA 3 mm data to study the kinematics of molecular outflows, their interaction with ionized outflows, and the star forming activity in the starburst region. We found that the gas ejected through molecular outflows is much more significant than that used to form stars.

• International Journal of Contents
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• v.17 no.1
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• pp.61-70
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• 2021

As the resolution of climate change scenario data applied with regional models increased, Earth System Grid Federation (ESGF) was established around major climate-related organizations to jointly operated and manage large-scale climate data. ESGF developed standard software to provide model output, observation data management, dissemination, and analysis using Peer to Peer (P2P) computing technology. Roles of each institution were divided into index and data nodes. Therefore, ESGF data node was established at APEC Climate Center in Korea on behalf of Asia to share data on climate change scenarios of CORDEX-East Asia (CORDEX-EA) to study climate changes in Eastern Asia. Climate researchers are expected to play a large role in researching causes of global warming and responding to climate change by providing CORDEX-EA regional model data to the world through ESGF data node.

• Communications for Statistical Applications and Methods
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• v.11 no.3
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• pp.465-474
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• 2004

Data visualization is the automation process and the discovery process to data sets in an effort to discover underlying information from the data. It provides rich visual depictions of the data. It has distinct advantages over traditional data analysis techniques such as exploring the structure of large scale data set both in the sense of number of observations and the number of variables by allowing great interaction with the data and end-user. We discuss the principles of data visualization and evaluate the characteristics of various tools of visualization according to these principles.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1046-1053
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• 2006

In the large scale recent reclaiming works performed within the wide spatial boundary, evaluation of long-term consolidation settlement and residual settlement of the whole construction area is sometimes made with the results of the limited ground investigation and measurement. Then the reliability of evaluation has limitations due to the spatial uncertainty. Additionally, in case of large scale deep excavation works such as urban subway construction, there are a lot of hazardous elements to threaten the safety of underground pipes or adjacent structures. Therefore it is necessary to introduce a damage prediction system of adjacent structures and others. For the more accurate analysis of monitoring information in the wide spatial boundary works and large scale urban deep excavations, it is necessary to perform statistical and spatial analysis considering the geographical spatial effect of ground and monitoring information in stead of using diagrammatization method based on a time-series data expression that is traditionally used. And also it is necessary that enormous ground information and measurement data, digital maps are accumulated in a database, and they are controlled in a integrating system. On the abovementioned point of view, we developed Geomonitor 2.0, an Internet based real time monitoring program with a new concept by adding GIS and geo-statistical analysis method to the existing real time integrated measurement system that is already developed and under useful use. The new program enables the spatial analysis and database of monitoring data and ground information, and helps the construction- related persons make a quick and accurate decision for the economical and safe construction.