• Structural Engineering and Mechanics
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• v.32 no.2
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• pp.321-335
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• 2009

When a roof frame is subjected to the airblast loading, the conventional way to analyze the damage of the frame or design the frame is to use single degree of freedom (SDOF) model. Although a roof frame consists of beams and girders, a typical SDOF analysis can be conducted only separately for each component. Thus, the rigid body motion of beams by deflections of supporting girders can not be easily considered. Neglecting the beam-girder interaction in the SDOF analysis may cause serious inaccuracies in the response values in both Pressure-Impulse curve (P-I) and Charge Weight-Standoff Diagrams (CWSD). In this paper, an inelastic two degrees of freedom (TDOF) model is developed, based on force equilibrium equations, to consider beam-girder interaction, and to assess if the modified SDOF analysis can be a reasonable design approach.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.38-44
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• 2003

Artificial blasts, defined as seismo-acoustic events, were discriminated from natural earthquakes in the Korean Peninsula by the seismo-acoustic analysis. Total 197 seismo-acoustic events corresponding to 9 percent of seismic events in 2002 were analyzed and classified as artificial surface blasts. Events distribution pattern of the seismo-acoustic events in 2002 was similar to the previous result in 1999-2001, except for two regions. Newly determined seismo-acoustic events were added to the previous artificial blast database. To extend infrasound detection capability, new small-scale infrasound array(TJIAR) was installed in KIGAM. Preliminary analysis for the small array was conducted to discriminate artificial blasts in the southwestern part of the Korean Peninsula. The small array discriminated S seismo-acoustic events during short period analysis. And two infrasound arrays(TJIAR and CHNAR) were used to determine approximate sound source location by cross bearing method.

• Journal of the Korea Society for Simulation
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• v.27 no.1
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• pp.101-109
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• 2018

Field experiments as well as numerical analyses with finite element analysis codes are two valuable and complemental ways to understand the structural response under explosive blast load. However, there seems to be only limited information available about finite element analysis and experimental validation on the response of structural components under internal explosions. For complementary use of the two ways, the numerical analyses should be validated with field experiments by comparing their results. In this paper, a small-scaled reinforced concrete building with a room is employed for experimental investigations. An amount of TNT is detonated at the center of the room. Pressure at three different sites in the room, displacement of centers of two walls, and damage patterns of four walls are measured and compared to results from numerical analyses. The experimental results are much similar to the numerical analyses results. The finite element analysis code ANSYS AUTODYN is employed to numerically analyze both pressure distribution inside the room and response of walls subjected to blast pressure. The feasibility and validity of the numerical analysis on the reponses of structural components under internal explosions are discussed in terms of structural damage assessment, and evaluated as the same damage in the analysis and the experiments.

• Journal of Electrical Engineering and Technology
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• v.10 no.5
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• pp.2046-2051
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• 2015

Currently, most high-voltage gas circuit breakers (CBs) include asymmetrical geometries in the shield, the tank, the hot-gas exhaust, and the connection parts for bushings. For this reason, a 3-dimensional (3-D) analysis of the insulation capability is necessary, rather than a 2-D analysis. However, a 3-D analysis has difficulties due to the computational time and complex modeling. This paper presents a 3-D analysis considering the asymmetry in high-voltage gas CBs and a technique to reduce the calculation time. In the proposed technique, the arc plasma requiring the most computational time is first calculated by a 2-D analysis. Then, the results such as pressure, temperature, and velocity are input as a source for the 3-D analysis. This technique is applied to a 145kV self-blast-type CB and the analysis result exhibits good agreement with the experimental result.

• Journal of the Korea Institute of Building Construction
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• v.4 no.4
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• pp.63-70
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• 2004

The objective of this study is to evaluate the compressive strength of recycled aggregate concrete by the non-destructive testing. Main experimental variables were the replacement level of recycled aggregate and blast-furnace slag, which were divided into two series according to recycled aggregate maximum size. Test results showed that a recycled aggregate had a significant influence on the non-destructive testing results, such as rebound number, Ultrasonic pulse velocity, and frequency. A prediction model of compressive strength considering the replacement level of recycled aggregate was suggested by multi-regression analysis and was compared with test results.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1287-1289
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• 1995

For the analysis of hot gas flow due to arc in puffer type $SF_6$ gas circuit breakers(GCBs), a program has been developed by adding function for arcing to the Fluid-in Cells(FLIC) method, which is often used for a two dimensional compressible flow problems, utilizing a simplified enthalpy flow arc model available for arcing. In this paper, the results of arc modelling for 800kV GCB are presented and compared with that of cold gas flow in the interrupters. It is shown that the nozzle clogging is the dominating factor in the pressure rise of the puffer chamber. It permits to estimate the dielectric strength of interrupters.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.205-208
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• 2015

Some euryalid specimens were collected with fishing nets from Mipo, Gyungsangnamdo and Aewol, Jejudo Island, Korea. They were identified as Gorgonocephalus eucnemis (${M\ddot{u}ller}$ & Troschel, 1842), belonging to family Gorgonocephalidae of order Euryalida, which was new to the Korean fauna. Their molecular analyses were done with newly intended COI primers of mitochondrial cytochrome oxidase I (COI) gene for the accurate molecular identification. The Korean G. eucnemis was coincident with this NCBI species as a result of Blast analysis, which showed the 99% similarity. In the current study, three Gorgonocephalus species have been reported from Korea.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.271-274
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• 2007

Lately, there are actively proceeding in making a plan for subway construction, a high-speed railway construction and a expansion of road and also all kinds of large-scaled construction in Korea. Construction works were delayed from noises and vibrations occurred by usage of a large-sized construction equipments and driven and also blast or there were often stopped from them under construction. Therefore, this study was modeling operation of the cyclic loading and conforming effects from grasping displacement-changing method through a variable analysis.

• Research in Plant Disease
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• v.25 no.4
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• pp.205-212
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• 2019

Analysis of differentially expressed genes has assisted discovery of gene sets involved in particular biological processes. The purpose of this study was to identify genes involved in appressorium formation in the rice blast fungus Magnaporthe oryzae via analysis of cDNA-amplified fragment length polymorphisms. Amplification of appressorial and vegetative mycelial cDNAs using 28 primer combinations generated over 200 differentially expressed transcript-derived fragments (TDFs). TDFs were excised from gels, re-amplified by PCR, cloned, and sequenced. Forty-four of 52 clones analyzed corresponded to 42 genes. Quantitative real-time PCR showed that expression of 23 genes was up-regulated during appressorium formation, one of which was the MCK1 gene that had been shown to be involved in appressorium formation. This study will be providing valuable resources for identifying the genes such as pathogenicity-related genes in M. oryzae.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.183-188
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• 2002

When Concrete work during winter is placed, it has anxiety that concrete freeze at low temperature. As concrete's freezing cause reduction of durability, it is necessary for mixing to pay attention to Air content and W/C ratios. Accordingly, in this study, we set up three series and evaluate a frost-resistance of concrete with admixture, like fly-ash and blast-furnace slag, for early curing method and types of chemical admixture..The study is composed as; I series : Analysis for early curing method and types of chemical admixture in laboratory II series : Analysis for early curing method and types of chemical admixture in batcher plant and measured concrete' temperature. The result of this study, it was more effective the use of super-plasticizers than air entraining agent.