• Korean journal of applied entomology
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• v.29 no.3
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• pp.170-175
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• 1990

These studies were conducted to examine the mechanism of acaricidal resistance in the twospotted spider mite (Tetranychus urticae Koch). The resistant strains were obtained by succssive selection of five acaricides including carbonphenothion and ethion of organophosphorus compound, dicofol of organochlorine compound, cyhexatin of compound and biphenthrin of synthetic pyrethroid. Esterase isozymes were separated by polyacrlyamide gel susceptible strains. The differences of the esterase isozymes of the resistant strains were Est. 1, Est. 3 in the carbonphenothion-selected strain, Est. 3 in the ethion- and the cyhexatin-selected strains, Est. 1, Est. 3, Est. 7 in the dicofol-selected strain, Est. 7 in the biphenthrin-selected strain as compared to the susceptible strain. With the difference of electrophoretic bands and their activities, esterases were related to the resistant mechanism of tested acaricides.

• Genomics & Informatics
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• v.4 no.4
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• pp.170-172
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• 2006

ESTin is an easy-to-use tool that allows EST researchers to build a dbEST submission file with EST sequences and related data. The advantages of ESTin are its user-friendly interface, various editing functions, and rigorous validation function.

• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.4
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• pp.253-259
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• 1992

The esterase isozyme in tissue of wild legume plants were separated by horizontal starch gel electrophoresis. Extracts used in this study were prepared from fully expanded young leaf, cotyledon and radicle of seedling and root-nodule of Glycine sola, Vigna vexillata var. tsuscmensis and Trifoliwn repens. The results are as follows; 1. Each tissue examined had a characteristic banding pattcrn. Number of bands in each species, G. soja, V. vexillata, and T . repens, were 14, 8 and 1 1 bands, respectively. And difference in esterase isozyme bands were greater from tissue to tissue than difference between habitat. 2. Est-I, Est-2. Est-3 and Est-4 in G. soja, Est-I in V. vexillata and Est-l and Est-2 in T. repens showed strong cnzyme activity than other enzyme. 3. Esterase isozyme variation in G. soja and T . repens showed more variety than V. vexillata. This is resulted from many genotypic differences within species. 4. The main enLyme among thc esterase isozyme were Est-I. Est-2, Est-3 and Est-4.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.3
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• pp.259-266
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• 2004

In this paper. a new two types of EST(Emitter Switched Thyristor) structures are proposed to improve the electrical characteristics including the current saturation capability. Besides, the two dimensional numerical simulations were carried out using MEDICI to verify the validity of the device and examine the electrical characteristics. First, a vortical trench electrode EST device is proposed to improve snap-back effect and its blocking voltage. Second, a dual trench gate EST device is proposed to obtain high voltage current saturation characteristics and high blocking voltage and to eliminate snap-back effect. The two proposed devices have superior electrical characteristics when compared to conventional devices. In the vertical trench electrode EST, the snap-back effect is considerably improved by using the vertical trench gate and cathode electrode and the blocking voltage is one times better than that of the conventional EST. And in the dual trench gate EST, the snap-back effect is completely removed by using the series turn-on and turn-off MOSFET and the blocking voltage is one times better than that of the conventional EST. Especially current saturation capability is three times better than that of the other EST.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11C
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• pp.682-693
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• 2011

Energy spreading transform (EST) based modulation is an effective technique to combat frequency-selective fading in broadband wireless communication. It performs close to the inter-symbol interference (ISI)-free matched filter bound (MFB) only at the complexity of a linear detector. Originally, EST-based modulation has been proposed for QPSK. However, to fully utilize the capacity of multipath fading channels, higher-order modulations are also necessary. In this paper, we review the EST based modulation that has originally been proposed for QPSK and discuss its extension to 8 PSK and 16 QAM. The performance of the extended system is verified through simulation in Proakis B and 8-tap fading channel. The EST based modulation for 8 PSK shows the performance which is very close to MFB and the EST based modulation for 16 QAM shows the performance gap between its receiver and MFB.

• The Korean Journal of Pesticide Science
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• v.11 no.3
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• pp.171-178
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• 2007

Esterase isozymes were extracted from final instar larvae of M. saltuarius treated with selective diets and inhibitors. Twenty esterase isozymes were separated on 12% native-PAGE gel and stained with three different substrates(${\alpha}$-naphthyl acetate, ${\beta}$-naphthyl acetate, or ${\alpha}$-naphthyl butyrate). Interestingly, the isozymes of Est7(${\alpha}$-naphthyl acetate and ${\alpha}$-naphthyl butyrate) and Est6(${\beta}$-naphthyl acetate) were specifically activated in final instar larvae fed with the bark of Pinus koraiensis. However, we could not find any band from substrate ${\beta}$-naphthyl stearate. The esterase activities of Est3, Est6, and Est7 were inhibited by organophosphate and carbamate insecticides. In addition, The esterase activities of Est4, Est6, and Est7 were also inhibited by eserine. However, inhibition of esterase activities in methoprene, bornyl acetate, linal, cineol, and citral was not observed. However, It is necessary to reconfirm these results in vivo.

• The Korean Journal of Pesticide Science
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• v.11 no.3
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• pp.179-185
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• 2007

Esterase isozymes were investigated from digestive juice of M. saltuarius adults after pesticide treatment. Twelve esterase isozymes were separated on 12% native-PAGE gel and stained with three different substrates(${\alpha}$-naphthyl acetate, ${\beta}$-naphthyl acetate, and ${\alpha}$-naphthyl butyrate). Interestingly, the isozyme of Est1(${\alpha}$-naphthyl acetate) was strongly inhibited by the carbofuran and methomyl. The Est1 activity was completely inhibited by the chlorpyrifos and partially inhibited by methidation about 70 %. In addition, eserine suppressed esterase isozyme activities of Est1 about 70% and isozyme activities of Est2, Est3, and Est4 were weakly inhibited. ${\alpha}$-pinene did not suppressed esterase isozyme activities but activities of esterases were very weakly inhibited in camphor and bornyl acetate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.465-470
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• 2002

This study presents results of electro-phoretically detectable isozyme variation in Crossing Block (CB) lines of two-rowed barley maintained by the National Crop Experiment Station. The specific objectives were to determine allelic frequencies at the four Est loci(Est1, Est2, Est4, and Est5) and their distribution over 380CB lines of two-rowed barley. A total of 17 alleles were detected over the four Est loci in these lines. There were 4 alleles (Pr, Al, Ca, and Af at the Est1 locus and their frequencies were 69.7, 1.1, 28.4, and 0.8%, respectively. At the Est2 locus, 5 different alleles (Dr, Fr, Sp, Un and a recessive null allele) were detected and their frequencies were 2.9,84.5,0.5,2.1, and 10%, respectively. four alleles (Nz, Su, At, and null were detected at the Est4 locus and the allelic frequency of Su was about 84%. Four alleles(Mi, Pi, Te, and a null allele(od)) were detected at the Est5 locus and their frequencies were 34.2, 61.0, 2.4, and 2.4%, respectively. Based on the allelic frequencies over the four Est loci, 380 CB lines were classified into 25 genotypes. The most frequent genotypes were G1(Pr-Fr-Su-Mi) and G2(Pr-Fr-Su-Pi), and their frequencies were 28.1 and 39.5%, respectively. The frequencies of other genotypes were less than 10%.

• Transactions on Electrical and Electronic Materials
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• v.4 no.2
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• pp.15-19
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• 2003

In this paper, the new dual trench gate Emitter Switched Thyristor (DTG-EST) is proposed for improving snap-back effect which leads to a lot of serious problems of device applications. Also the parasitic thyristor that is inherent in the conventional EST is completely eliminated in this structure, allowing higher maximum controllable current densities for ESTs. The conventional EST exhibits snap-back with the anode voltage and current density 2.73V and 35A/$\textrm{cm}^2$, respectively. But the proposed DTG-EST exhibits snap-back with the anode voltage and current density 0.96V and 100A/$\textrm{cm}^2$, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.3
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• pp.183-189
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• 2010

In this paper, the trench gate emitter switched thyristor(EST) withl trench gate electrode is proposed for improving snap-back effect which leads to a lot of problems in device applications. The parasitic thyristor which is inherent in the conventional EST is completely eliminated in this structure, allowing higher maximum controllable current densities for ESTs. The dual trench gate allows homogenous current distribution in the EST and preserves the unique feature of the gate controlled current saturation of the thyristor current. The characteristics of the 1700 V forward blocking EST obtained from two-dimensional numerical simulations (MEDICI) is described and compared with that of a conventional EST. we carried out layout, design and process of EST devices.