• Journal of the Korean Geophysical Society
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• v.5 no.4
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• pp.329-336
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• 2002

Electrical resistivity dipole-dipole, seismic refraction, and seismic reflection methods were performed to delineate the boundaries the Yongdong basin(Cretaceous) in terms of physical properties and to ultimately identify the margin architectures of the faults or unconformities. Higer resistivities (approximately >2000 ohm-m) most likely originate from the basement of the basin, contrasting with the lower resistivities from infilled sedimentary rocks. Faults at the eastern margin and unconformities at the western boundary are characterized as high-slope($70^{\circ}$) and gentle-slope($30^{\circ}$) gradients in the resistivity sections, respectively Such features for the boundaries are also suggested by the lower values of seismic velocity and resistivity for the western margin.

• Journal of Korean Society of Steel Construction
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• v.22 no.4
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• pp.389-398
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• 2010

The flexural strength of composite HSB I-girders under a positive moment was investigated using the moment-curvature analysis method to evaluate the applicability of the current AASHTO LRFD design specifications to such girders. A total of 2,391 composite I-girder sections that satisfied the section proportion limits of the AASHTO LRFD specifications was generated by the random sampling technique to consider a wide range of section properties. The flexural capacities of the sections were calculated inthe nonlinear moment-curvature analysis in which the HSB600 and HSB800 steels were modeled as an elasto-plastic strain-hardening material, and the concrete, as a CEB-FIP model. The effects of the ductility ratio and the compressive strength of the concrete slab on the flexural strength of the composite girders made of HSB and SM520-TMC steels were analyzed. The numerical results indicated that the current AASHTO LRFD equation can be used to calculate the flexural strength of composite girders made of HSB600 steel. In contrast, the current AASHTO LRFD equation was found to be non-conservative in its prediction of the flexural strength of composite HSB800 girders. Based on the numerical results of this study for 2,391 girders, a new design equation for the flexural strength of composite HSB800 girders in a positive moment was proposed.

• Research in Plant Disease
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• v.25 no.1
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• pp.1-7
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• 2019

The rice blast fungus, Magnaporthe oryzae, is one of the most economically important crop diseases. In addition, rice-M. oryzae interaction is a classical gene-for-gene host-pathogen system. Race variation in pathogen groups was proposed as the main mechanism for rapid break-down of resistance in newly introduced rice cultivars. These new pathogen race variations may be caused by changes in an avirulence gene, such as (i) point mutations, (ii) insertion of transposons, and (iii) frame shifts. The avirulence gene AVR-Pita1 is representative avirulence gene in which all of these mutations are reported. In this review, we present a useful information for avirulence gene AVR-Pita1 and its homologous genes AVR-Pita2 and AVR-Pita3. We also review examples that cause mutations in these evolutionarily significant genes.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.127-127
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• 2003

벼 도열병 저항성 조절과정을 연구하는 효율적인 방법은 돌연변이를 분리하여 해당유전자를 분석하는 것이다. 이를 위하여 벼에서 제조된 4가지 돌연변이 집단을 이용하여 도열병 저항성 돌연변이를 분리하였다. 실험재료로는 1) fast neturon을 처리하여 제조된 Moroberekan 2,000 라인, 2)T-DNA의 형질전환에 의해서 제조된 화영 1,000 라인, 3)DEB처리에 의해서 제조된 RIL260 3,000라인, 4) gamma ray 처리에 의해서 제조된 상해향혈나 10,000 라인 등이 사용되었다. 병 저항성이 감소된 돌연변이의 분리를 위하여 재료로 사용된 벼 품종과 비친화적 상호작용을 보이는 균주의 포자를 2-3주된 벼 잎에 직접 살포하는 방법을 이용하였다. 균주 접종 7 일 후에 blast lesion을 형성하거나 lesion mimic 표현형을 보이는 돌연변이 등 병저항성이 감소된 라인을 선별하였다. 현재까지 1) Moroberakan 5 라인, 2) 화영 4 라인, 3) RIL260 1 라인 등이 선별되었다. 이와 함께 병저항성이 현저히 증가된 돌연 변이를 선별하기 위하여 친화적인 균주를 사용한 실험에서는 상해향렬나 2 라인이 선별되었다. 선별된 돌연변이는 벼 도열병 저항성 유전자의 분리 및 저항성 조절기작을 연구하는데 효과적으로 사용될 것이다.

• Journal of Energy Engineering
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• v.10 no.2
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• pp.114-119
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• 2001

TRIGA Mark-II&III 연구로서의 운영과정에서 발생된 방사성 슬러리 함유 폐액에 대하여 음이온, 앙이온, 그리고 비이온 응집제를 첨가하였을 때의 여과 효과를 실험실 규모의 진공여과 장치로 연구하였다. 여과 실험 자료를 이용하여 Darcy’s Law에서 유도된 여과 케익 저항 값을 산출하였다. 응집제 사용으로 응집제를 사용하지 않은 경우롸 비교하여 케익 저항값의 개선은 있었지만, 수분함량은 증가하였다. 각각의 응집제 사용에 따른 침전율, 여과 케익의 수분함량, 그리고 여과 케익 저항 값을 비교한 결과 음이온 응집제 12~16ppm/$\ell$ waste를 사용하였을 경우가 가장 효과적인 것으로 나타났다.

• Proceedings of the KSEEG Conference
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• 2002.04a
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• pp.104-106
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• 2002

• Korean Journal Plant Pathology
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• v.1 no.2
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• pp.115-121
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• 1985

To improve methods of screening rice cultivars with field resistance to bacterial leaf blight, testing plant inoculation and neighbor plant inoculation were compared by using 33 rice cultivars. In the testing plant inoculation method, field resistance was evaluated by measuring the leaf areas diseased on the new leaves expanded after the inoculation. Varietal differences in field resistance were recognized more clearly by the testing plant inoculation method than by the neighbor plant inoculation method. Highly significant correlation was observed between the results of the two methods. Some rice cultivars such as, Seomjin, Hangangchal, Taebaeg, Samgang, Milyang 42, Asominori, Java 14, Chugoku 45 and 70X-46 showed remarkable field resistance to bacterial leaf blight. The testing plant inoculation method appeared desirable for screening rice cultivars for the qualitative and field resistance to bacterial leaf blight because of using less labor and less field area than neighbor plant inoculation.

• The korean journal of orthodontics
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• v.36 no.3 s.116
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• pp.207-217
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• 2006

Although ceramic brackets have been used widely for improved esthetics during treatment, ceramic brackets have some inherent problems; brittleness, attrition of the opposing teeth and high frictional resistance. This study was performed to understand the frictional resistance of the ceramic brackets, as well as to be a helpful reference for finding the solutions to the problem of frictional resistance. Three different kinds of brackets were used; metal bracket, polycrystalline ceramic brackets with a metal slot to reduce the high frictional resistance and monocrystalline ceramic brackets. The brackets were tested with a $.019{\times}.025$ stainless steel wire with a second order angulation of $0^{\circ}\;and\;10^{\circ}$, and the static and kinetic frictional forces were measured on the universal testing machine. The results of this study showed that the ceramic brackets, especially the monocrystalline ceramic bracket without a metal slot, generated higher frictional resistance than the metal bracket, and the frictional resistance was increased as the angulation between the bracket slot and the wire increased. Therefore, the development of the ceramic bracket with reduced frictional resistance and the prevention of excessive crown tipping during orthodontic treatment will lead to the simultaneous attainment of more efficient and improved esthetic treatment goals.

• Journal of the Korean Magnetics Society
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• v.8 no.5
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• pp.282-287
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• 1998

Dependence of magnetoresistance on base pressure and deposition rates of each Fe, Co, Cu layers in the $Fe(50{\AA}/[Co(17{\AA})/Cu(24{\AA})]_20$ multilayer thin films, prepared by dc magnetron sputtering on Corning glass, were investigated. AFM analysis, X-ray diffraction analysis, vibrating sample magnetometer analysis, and magnetoresustance measurement (4-probe method) were performed. The multilayer films deposited under low base pressure increases magnetoresistance ratio by preventing oxidation. Annealing for the samples at a moderate temperature allowed larger textured grain with no loss in the periodicity. Magnetoresistance ratio of the annealed multilayers was increased due to the increase antiferromagnetically coupled fraction of the film after annealing. Optimization of deposition rate was greater than 1 $\AA$/s for Fe, and 2.8 $\AA$/s for Cu. Deposition rate of Co showed a tendency of increasing of magnetoresistance ratio due to the formation of flat magnetic layer in case of high deposition rate of Co.

• The Journal of Engineering Geology
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• v.14 no.1
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• pp.21-28
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• 2004

Three-dimensional (3-D) resistivity inversion including a topographic effect can be considered theoretically to be the technique of acquiring the most accurate image in the interpretation of resistivity data, because it includes characteristic image that the actual subsurface structure is 3-D. In this study, a finite-element method was used as the numerical method in modeling, and the efficiency of Jacobian calculation has been maximized with sensitivity analysis for the destination block in inversion process. Also, during the iterative inversion, the resolution of inversion can be improved with the method of selecting the optimal value of Lagrange multiplier yielding minimum RMS(root mean square) error in the parabolic equation. In this paper, we present synthetic examples to compare the difference between the case which has the toprographic effect and the other case which has not the effect in the inversion process.