• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.397-408
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• 2004

The aim of this paper is to study the interaction between adjacent buildings with different foundation levels under earthquake loading conditions. Buildings and soil are represented by two different models. In the first case, the building itself is modeled with standard frame elements, whereas the soil behavior is simulated by a special grid model, In the second case, the building and soil are represented by plane stress or plane strain elements. The modulus of elasticity of the ground as well as the varying relations of inertia have a strong influence on the section forces within the buildings. The interaction between the two buildings is demonstrated and discussed via numerical examples using the proposed method.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.444-448
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• 1998

This paper presents the results of an experimental investigation on the compaction and compressive strength of polypropylene fiber reinforced soils. This study has been performed to obtain the physical properties of PFRS(polypropylene fiber reinforced soil) such as strain-stress relationships, OMC(optimum moisture contents) and ${\gamma}$$_{dmax}$ (maximum dry unit weight), with four different concentrations(i.e., 0.1%, 0.3%, 0.5% and 1.0% weights) of mono-filament and fibrillated polypropylene fibers. The test results indicate an appreciable increase in strength due to addition of fibers. OMC is increased with the concentration ratio of fiber, but ${\gamma}$$_{dmax}$ is decreased. From the viewpoint of strength, the fibrillated polypropylene fiber soil is more effective than the mono-filament polypropylene fiber soil.oil.

• Microbiology and Biotechnology Letters
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• v.23 no.1
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• pp.91-97
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• 1995

The 543 microbial strains were isolated from the rhizosphere in ginseng root rot-suppressive soil. From these, isolate KGM-100 was finally selected for the screening of powerful antagonistic bacterium for the soil-born Fusarium solani causing root rot of many important crops. The isolate KGM-100 was identified as Pseudomonas aeruginosa. Antibiotics produced by the P. aeruginosa KGM-100 were partially characterized as heat-stable and low-molecular weight antibiotics. The strain also produced siderophore, which was assumed to be pseudobactin. Pot test showed approximately 30-50% biological control effects when Fusarium solani-infected soil was treated with the P. aeruginosa KGM-100.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.34-39
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• 1998

For more convenient and rapidly isolation of Bacillus thuringiensis subsp. israelensis(Bti), 1) heat treatment spore forming bacteria, 2) growth in enrichment culture media for Bacillus sp. and 3) selection of bacteria producing a lecithinase for Bacillus thuringiensis subsp. israelensis, were performed. Spore forming bacteria were counted 4.8 $\times $ 10$^{8}$cells/g soil on NAPGCY media, 9.2 $\times $ 10$^{7}$cells/g soil on NA media, and 3.6 $\times $ 10$^{8}$cells/g soil on NAAC media, respectively. Bacteria producing only a lecithinase were reached at 25.2% on medium contained egg york, bacteria only producing a delta-endotoxin were reached at 23.2% by phase contrast microscope, and bacteria producing a lecithinase & a delta-endotoxin simultaneously were reached at 13.7%. Bacillus thuringiensis which producing a lecithinase and a delta-endotoxin simultaneously among bacteria producing a lecithinase, were reached at 56.5%; A half of Bacillus thuringiensis was produced a delta-endotoxin, but not produced a lecithinase. Among 8 isolates of Bacillus thuringiensis, two strain of Bti which has a mosquito-cidal toxin, were detected by PCR using a specific primer of $\delta $-endotoxin gene from Bti.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.163-170
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• 2001

This paper presents results of nonlinear analyses for underground structures including both the soil-structure interaction and nonlinear behavior of concrete material. For this purpose, a hybrid method is employed, in which a dynamic analysis technique for a linear soil-structure interaction system and a general purpose FE program are combined in hybrid and practical manners. A couple of nonlinear analyses are carried out for framed structures in multi-layered half space soil medium. The yielding of concrete structure is considered by a multi-linear stress- strain relationship. The numerical results suggest that ductile design fur the intermediate columns in the underground framed structure is substantially important in aseismic design.

• Journal of Ocean Engineering and Technology
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• v.22 no.6
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• pp.1-6
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• 2008

Anchors have been commonly used to as foundation systems of the structures that require the uplift resistance. Recently anchors have been used in ocean sediment for mooring systems to stabilizeoffshore structures. In the saturated clayey soil however suction developed between the soil and andchor and affects the uplift capacity of anchor. To estimate the uplift capacity of the andchor accurately, the failure mechanisms of the andchor by the uplift force should also be correctly assumed. The uplift capacity is usually expressed in terms of breakout factors with respect to embedment ratio. In this paper, a two-dimensional plane strain numerical investigation into the vertical uplift capacity of a plate andchor in a clayey soil is described. The breakout factor against their corresponding values of embedment ratio was calculated and plotted along a single curve. The modes of failure mechanism at shallow and deep andchors are also presented.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.940-951
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• 2009

A comparative study on dynamic and static measurement of initial stiffness was conducted. Because soil stiffness decreases even at very small strains, the initial stiffness has been measured by dynamic tests using shear wave velocity measurement. On the other hand, due to the advance of local strain measurement, the triaxial testing device is capable of measuring the static initial stiffness. It has been known that initial stiffness measured by static triaxial tests is generally lower than that measured by dynamic tests possibly due to the limitation of static measurement of displacement at very small strains. This study presents experimental results indicating that the elastic shear moduli could be the same both in dynamic and static measurements owing to the soil anisotropy induced by anisotropic stresses.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1997.04a
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• pp.265-272
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• 1997

This paper presents the result of an international cooperative research on the post-correlation analysis of forced vibration tests and the prediction of earthquake responses of a large-scale seismic test structure. Through the post-correlation analysis, the properties of the soil layers are revised so that the best correlation in the responses may be obtained compared with the measured force vibration test data. Utilizing the revised soil properties as the initial linear values, the seismic responses are predicted for an earthquake using the equivalent linearlization technique based on the specified strain dependent characteristics of the shear moduli and damping ratios. It has been found that the predicted responses by the equivalent nonlinear procedure are in excellent agreement with the observed responses, which those using the initial properties are fairly off from the measured results.

• The Korean Journal of Mycology
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• v.44 no.4
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• pp.360-364
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• 2016

Fungal strain KNU16-005 was isolated from field soil in Jeollabuk-do, Korea. Based on its morphological characteristics and phylogenic analysis using internal transcribed spacer regions of rDNA, ${\beta}$-tubulin and translation elongation factor 1-alpha gene sequences of KNU16-005 were identified as Neopestalotiopsis australis. This species has not been previously reported in Korea.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1747-1755
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• 2008

Design of the reinforced roadbed thickness is concerned with safe operation of trains at specified levels of speed, axle load and tonnage. There are two methods for evaluating it. One is using an experimental equation and the other is using elastic theory with considering axle load, material properties of subsoils and allowable elastic settlement. Multi-layered theory is used to determine reinforced roadbed thickness by RTRI. Although their reinforced roadbed thickness is designed with an objective of achieving a minimum standard 2.5mm of settlement on the subgrade surface, it is hardly applied to real design. Li(1994) has suggested the experimental model which design approach is to limit plastic strain and deformations for the design period. It is worth due to adopting soil equivalent number of repeated load application. Moreover, it has been a more advanced method than existing design methods because including resilient modulus of subsoil beneath track, soil deviator stress caused by train axle loads and MGT. In this paper, it is analyzed under domestic track conditions to estimate the reinforced roadbed thickness with different soil types.