• Korean Journal Plant Pathology
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• v.1 no.1
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• pp.22-27
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• 1985

Localized resistance against a virulent race of Erysiphe graminis f. sp. hordei by prior inoculation of a virulent or an avirulent race of the same fungus was induced on the near-isogenic barley leaves. Induced resistance could be detected within one hour following challenge inoculation with a virulent or an avirulent inducer race, hut the resistance increased greatly as the interval between the two inoculations was increased, showing the highest level by 6-9 hours of exposure to the inducer race. The level of the induced resistance was proportional to the amount of inducer inoculum applied. The resistances elicited by virulent or avirulent inducer races were similar with respect to the level of resistance and the time needed for its induction.

• Economic and Environmental Geology
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• v.36 no.1
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• pp.49-58
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• 2003

To analyze the anisotropic characteristics of fractured aquifer, variations of streaming potential were measured during and after pumping over several wells at the two test sites. Surface electrical resistivity survey, normal resistivity logging, and slug test were performed at the wells to identify the hydrogeological structure. Applying the results to the recently suggested model, the aquifer of the two test sites showed confined characteristics. Anisotropic direction appeared in using equi-potential maps from self-potential monitoring results matched well with the results of the hydrogeological test. The self-potential monitoring method adopted in this study would be useful for providing a more reliable information on the anisotropy of aquifer in the pumping test at single well.

• Journal of the Korean earth science society
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• v.36 no.1
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• pp.59-67
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• 2015

An electrical resistivity survey is widely conducted for the safety management of embankment. In this study we investigated how a tidal variation affects the interpretation of electrical resistivity monitoring data of the embankment located in west coast. We monitored the variation of electrical resistivity on the coastal embankment where there was a high tidal variation for 3 days in every 3 hours. Electrical resistivity monitoring data showed a variation of resistivity distribution in specific area according to the time, which demonstrated some correlation with a tidal height variation. Therefore, we highly recommend that a tidal effect be considered when electrical resistivity survey is conducted on the embankment where there is a high tidal variation. For further study, we need a long term electrical resistivity monitoring and analyzing on tidal variation.

• Geophysics and Geophysical Exploration
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• v.8 no.3
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• pp.218-223
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• 2005

This study considers to electrical resistivity characteristics for clay minerals types and contents in fractured and fault zone. The electrical resistivity is measured for an artificial agar specimen with clay minerals instead of a natural rock. The artificial agar specimen with clay minerals was special worked in study. The clay minerals used are Kaolinite and Montmorillonite in test, the clay mineral contents increases until $0\~40\%$ to the same specimen. As results, the electrical resistivity of the specimen decreased gradually as the clay mineral contents increases for all types of clay minerals. Montmorillonite shows remarkably lower resistivity than Kaolinite, although its clay content is fewer than that of Kaolinite. Also, a proposed experimental expression shows a good correlation coefficient as high as 0.89 or more in all clay minerals.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.206.2-206.2
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• 2013

무기물/유기물 나노복합체로 제작한 유기 쌍안정성 형태의 메모리 소자는 공정이 단순하고 뛰어난 유연성을 갖고 있기 때문에 플렉서블 메모리 소자에서 많은 연구가 진행되고 있다. 그러나 다양한 연구에도 불구하고 절연성 고분자 박막 내부에 분산 된 나노입자를 이용하여 제작한 저항성 구조의 비휘발성 메모리 소자의 전하수송 메커니즘에 대한 연구는 미흡하다. 본 연구에서는 CuInS2 (CIS)/ZnS 나노입자가 분산되어 있는 절연성 고분자 박막을 사용한 기억소자의 전하수송 메커니즘을 규명하였다. 본 연구는 indium-tin-oxide (ITO)가 코팅된 플렉서블 polyethylene terephthalate (PET) 기판을 화학물질로 세척한 후 CIS/ZnS 나노입자와 절연성 고분자인 poly(N-vinylcarbazole)가 혼합된 용액을 스핀코팅 방법으로 도포했다. 도포된 용액에 열처리를 하여 용매를 제거한 후, 형성된 박막을 저항 변화 층으로 사용하였다. 제작된 메모리 소자는 Al 상부 전극을 고 진공에서 열 증착 방식을 이용하여 PET/ITO/CIS-ZnS 나노입자가 분산된 절연성 고분자/Al 구조를 갖는 저항성 기억 소자를 제작하였다. 소자의 전류-전압 (I-V) 특성 결과는 같은 전압에서 전도도가 높은 상태 (ON)와 낮은 상태 (OFF)가 존재하는 걸을 관찰하였다. 실험을 통해 두 상태 변화를 일으키는 일정 전압을 가하기 전까지 각각의 ON 또는 OFF 상태를 계속 유지하여 비휘발성 메모리 소자로 활용할 수 있음을 확인 할 수 있었다. ON 또는 OFF 상태의 전기적 스트레스를 측정으로 ON과 OFF 상태가 안정성을 가지는 것을 관찰 하였다. I-V 특성 결과를 기초로 메모리 소자의 전하수송 메커니즘을 규명 하였다.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.345-351
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• 2011

This study was carried out to develop a model system using selection method for disease resistant plant breeding programs using a herbicide bialaphos-resistant patII gene as a gene-based marker. Spraying bialaphos could eliminate the susceptible plants from the segregating populations such as ${F_2}^{\prime}s$ and thereafter. Tomato cv. Momotaro-yoke was transformed with patII gene 60 independent transformants were acquired. Total 42 transformants were analyzed in transgene copy numbers by Southern blotting and the segregation ratios for the bialaphos resistance. Statistical analysis revealed that the transgene copy numbers and the segregation ratios were not always coincided, especially having the tendency of underestimating the real numbers of the transgenes in the multicopy lines. A two-stepwise screening method was applied to select $T_1$ tomato plants which linked the transgenic patII to a disease resistance gene (I2 and Ve). Based on the resistant to susceptible ratios, T-20 plant was finally selected due to the estimated linkage 12-13 cM between the patII gene to the I2 gene on chromosome 11. This newly developed system could be applied to any economical crop in breeding programs.

• Korean journal of applied entomology
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• v.29 no.3
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• pp.194-200
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• 1990

The diamondback moth (Plutella xylostella L.) was selected over 24 generations with fenvalerate. The resulting resistant strain was tested to study development of insecticide resistance and cross resistance to some insecticides in the laboratory. Insecticide resistance of diamondback moth at the 24th generation devleoped 66.2 fold compared to the parent strain for fenvalerate. The fenvalerate selected strain exhibited 145 fold, a high level of cross resistance to deltamethrin, and also showed 17.4-45.0 fold cross resistance to alphamethrin, cypermethrin, fenvalerate, permethrin, and tetramethrin in the pyrethroid insecticides. The fenvalerate selected strain showed 2.5-4.3 fold, low cross resistance to diazinon, dichlorvos, EPN, BPMC, cabaryl, and methomyl. However, it did not show cross resistance to acephate, fenitrothion, phenthoate, and carbofuran.

• Korean journal of applied entomology
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• v.30 no.1
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• pp.1-9
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• 1991

Cross-resistance and inheritance of resistance in laboratory-selected strains of the brown planthopper to various types of the insecticides were investigated. The fenobucarb-selected ($R_{f}$), carbofuran-selected($R_{c}$), and diazinon-selected($R_{d}$) strains were 50.3, 49.2 and 5.8 times less sensitive to the corresponding insecticides than th susceptible strain. both $R_{f}$ and $R_{c}$ strains were highly resistant to the other carbamate insecticides, and moderately resistant to cypermethrin and deltamethrin, but nearly not resistant to fenvalerate and the organophosphorus insecticides except malathion and phenthate. Moderate resistance to malathion and phenthoate in the $R_{f}$ and $R_{c}$ strains was obtained at the rate of 13.0-12.0 and 8.5-7.5 times, respectively. The $R_{d}$ strain showed low levels of resistance to the carbamate, organophosphorus and pyrethroid insecticides, but negatively correlated cross-resistance to fenvalerate. Resistance of the brown planthopper to all the test insecticides was inherited by partially dominant autosomal factor(s).

• Geophysics and Geophysical Exploration
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• v.22 no.3
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• pp.160-167
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• 2019

Resistivity inversion result may be distorted if the seepage line fluctuation within central core with the change of reservoir water level as well as the conductivity of the reservoir water is not taken into consideration because the reservoir dike is composed of three-dimensional (3D) resistivity structure. Consequently, to accurately analyze the resistivity changes inside the reservoir dike according to the change of reservoir water level, 3D electrical resistivity modeling for the 2D survey line considering topography and physical properties of dam components was carried out. In addition, 2D inversion was performed with the simulated 2D resistivity data for a given 3D model in order to compare it with the inversion result of real field data. For 283 reservoirs in Korea, 2D inversion results for the simulated 2D data and field 2D resistivity data were compared. Finally, the reservoirs with an inversion ratio of 50% or less were selected as reservoirs that require further precise investigation.

• Geophysics and Geophysical Exploration
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• v.24 no.3
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• pp.98-112
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• 2021

We followed and extended the algorithm originally made by Das (1995) to calculate the electric potential and field induced by electric current in arbitrary anisotropic layered structure. We confirmed all the theoretical contents and coded the corresponding program to acquire the electric potential and field. Further we extended to forward estimation of apparent resistivity to be attained by electrical resistivity survey on anisotropic layered structure with differing the electrode spacing and azimuth of anisotropy. The effects of anisotropy were reviewed by considering some examples.