• Journal of the Korean Society of Tobacco Science
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• v.20 no.2
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• pp.153-159
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• 1998

The vein necrotic strain of Potato Virus Y (PVY - VN) and black shank (Phyto-phthora parasitica var. nicotianae) are the two major diseases causing severe damages especially in burley tobacco (N. tabacum L.) area in Korea. A new tobacco variety, KB 111, resistant to PVY and black shank disease, was developed by Korea Ginseng & Tobacco Research Institute in 1997. It is a male sterile(MS) F$_1$ hybrid of the cross between MS TC 613 and KB 108. KB 111 was compared to Burley 21 on the agronomic characteristics and disease resistances in performance tests: It possessed upright growth habit and flowered two days later than Burley 21. It was resistant to both PVY and black shank and yielded about 3% more cured leaf than Burley 21, but other characteristics are very simiar to those of Burley 21. The chemical composition and physical properties of the cured leaf of KB 111 were as much acceptable as those of Burley 21 while it produced average yield of good quality leaf and appeared to resistant to PVY and black shank disease on regional farm test in 1998.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.613-618
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• 2011

To develop clubroot resistant Chinese cabbage inbreds, IT 033820, a clubroot resistant turnip, was cross pollinated with a Chinese cabbage inbred of BP 079. From 2005, conventional breeding and microspore culture method performed using these F1 plants as parental materials. In 2007, conventional breeding method resulted in 21 F3 inbreds. After inoculation of clubroot race 4, one inbred showing 83% resistant was selected and registered as 'onkyo 20036ho' in 2008. From 2005, we scanned hybrid cultivars using micro spore culture and developed many doubled haploid (DH) lines in Chinese cabbage. Using Chinese cultivar of 'oong-baek 2ho' we developed 26 DH inbreds in 2007. After inoculation of clubroot race 4, one DH inbred showing 77% resistant and yellow inner leaf color was selected and registered as 'onkyo 20034'in 2008. We found conventional breeding method was effective using introduced germplasm showing low germination. However, when using hybrid cultivar as starting material, microspore culture method was powerful for developing various inbred in short time.

• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.101-106
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• 2008

To identify inheritance of clubroot disease resistance genes in Chinese cabbage, seedling tests of $BC_1P_1,\;BC_1P_2$, and $F_2$ populations derived from $F_1$ hybrid(var. CR Saerona) using single spore isolate(race 4 identified with William's differential host) from Plasmodiophora brassciae were conducted. Resistance(R) and susceptible(S) plants segregated to 1:0 in backcross to the resistant parent. The $F_2$ population segregated in a 3(R):1(S) ratio. This result implied that the resistance of clubroot disease is controlled by a single dominant gene to the race 4 of P. brassicae in CR Saerona. To develop DNA markers linked to clubroot resistance genes, 185 plants of CR Saerona among $F_2$ populations were used. A total of 300 arbitrary decamer was applied to $F_2$ population using BSARAPD(Bulked segregant analysis-Randomly amplified polymorphic DNA). One RAPD marker linked to clubroot resistance gene in CR Saerona($OPJ_{1100}$) was identified. This marker was 3.1 cM in distance from resistance gene in $F_2$ population. This marker may be useful for a marker-assisted selection(MAS) and gene pyramiding of the clubroot disease resistant gene in Chinese cabbage breeding programs.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.2
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• pp.168-175
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• 2003

A new algorithm based on Genetic Algorithms is proposed f3r solving process optimization problems formulated in MINLP, GDP and hybrid MINLP/GDP. This work is focused especially on the design of the Genetic Algorithm suitable to handle disjunctive programming with the same level of MINLP handling capability. Hybridization with the Simulated Annealing is experimented and many heuristics are adopted. Real and binary coded Genetic Algorithm initiates the global search in the entire search space and at every stage Simulated Annealing makes the candidates to climb up the local hills. Multi-Niche Crowding method is adopted as the multimodal function optimization technique. and the adaptation of probabilistic parameters and dynamic penalty systems are also implemented. New strategies to take the logical variables and constraints into consideration are proposed, as well. Various test problems selected from many fields of process systems engineering are tried and satisfactory results are obtained.

• Plant Biotechnology Reports
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• v.2 no.2
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• pp.145-152
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• 2008

Aerides vandarum and Vanda stangeana are two rare and endangered vandaceous orchids with immense floricultural traits. The intergeneric hybrids were synthesized by performing reciprocal crosses between them. In vitro germination response of the immature hybrid embryos was found to be best on half-strength Murashige and Skoog medium supplemented with 20% (v/v) coconut water/liquid endosperm from tender coconut. Determination of hybridity was made as early as the immature seeds or embryos germinated in vitro, using randomly amplified polymorphic DNA (RAPD) markers. Out of 15 arbitrarily chosen decamer RAPD primers, two were found to be useful in amplification of polymorphic bands specific to the parental species and their presence in the reciprocal crosses. However, a decisive profile that can identify the reciprocal crosses could not be provided by RAPD. Amplification of the trnL-F non-coding regions of chloroplast DNA of the parent species and hybrids aided easy identification of the reciprocal crosses from the fact that maternal inheritance of chloroplast DNA held true for these intergeneric hybrids. Subsequent restriction digestion of the polymerase chain reaction (PCR) amplified trnL-F non-coding regions of chloroplast DNA also consolidated the finding. Such PCR-based molecular markers could be used for early determination of hybridity and easy identification of the reciprocal crosses.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.83-92
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• 2015

xBrassicoraphanus line BB#5, a new synthetic intergeneric hybrid between Brassica rapa L. ssp. pekinensis and Raphanus sativus L. var. rafiphera induced by N-methyl-N-nitroso-urethane mutagenesis in microspore culture, shows high seed fertility and morphological uniformity. Dual-color fluorescence in situ hybridization (FISH) using 5S and 45S rDNA probes and genomic in situ hybridization (GISH) using B. rapa genomic DNA probe were carried out to analyze the chromosome composition and the meiosis pairing pattern compared to its parental lines. The somatic chromosome complement is 2n = 38, which consists of 17 metacentric and two submetacentric chromosomes with lengths of 2.18 to $5.01{\mu}m$. FISH karyotype analysis showed five and eight pairs of 5S and 45S rDNA loci. GISH meiosis pairing analysis showed that 19 complete bivalents were most frequent and accounted for 42% of the 100 pollen mother cells examined. Based on chromosome number, size, morphology, rDNA distribution, and meiosis pairing pattern, both parental genomes of B. rapa and R. sativus appear to exist in xBrassicoraphanus line BB#5, demonstrating its genome integrity. Such stable chromosome constitutions and meiotic pairing patterns in somatic and meiotic cells are very rare in natural and synthetic intergeneric hybrids. Chromosomal studies and genetic and phenotypic changes in allopolyploids a re discussed. The results p resented h erein will b e usef ul f or f urther g enomic s tudy o f xBrassicoraphanus lines and their improvement as promising new breeding varieties.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.574-585
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• 2015

This paper aims to improve the performance of conventional direct torque control (DTC) drives proposed by Takahashi by extending the idea for 5-level inverter. Hybrid cascaded H-bridge topology is used to achieve inverter voltage vector composed of 5-level of voltage. Although DTC is very popular for its simplicity but it suffers from some disadvantages like- high torque ripple and uncontrollable switching frequency. To compensate these shortcomings conventional DTC strategy is modified for five levels voltage source inverter (VSI). Multilevel hysteresis controller for both flux and torque is used. Optimal voltage vector selection from precise lookup table utilizing 12 sector, 9 torque level and 4 flux level is proposed to improve DTC performance. These voltage references are produced utilizing a hybrid cascaded H-bridge multilevel inverter, where inverter each phase can be realized using multiple dc source. Fuel cells, car batteries or ultra-capacitor are normally the choice of required dc source. Simulation results shows that the DTC drive performance is considerably improved in terms of lower torque and flux ripple and less THD. These have been experimentally evaluated and compared with the basic DTC developed by Takahashi.

• Structural Engineering and Mechanics
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• v.16 no.2
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• pp.127-139
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• 2003

Reinforced concrete buildings with shearwalls are very efficient to resist earthquake disturbances. In general, reinforced concrete frames are governed by flexure and shearwalls are governed by shear. If a structure included both frames and shearwalls, it is generally governed by shearwalls. However, the ductility of ordinary reinforced concrete is very limited. To improve the ductility, a series of tests on framed shearwalls made of corrugated steel was performed previously and the experimental results were compared with ordinary reinforced concrete frames and shearwalls. It was found that ductility of framed shearwalls could be greatly improved if the thickness of the corrugated steel wall is appropriate to the surrounding reinforced concrete frame. In this paper, an analytical model is developed to predict the horizontal load-displacement relationship of hybrid reinforced concrete frame-steel wall systems according to the analogy of truss models. This analytical model is based on equilibrium and compatibility conditions as well as constitutive laws of corrugated steel. The analytical predictions are compared with the results of tests reported in the previous paper. It is found that proposed analytical model can predict the test results with acceptable accuracy.

• Smart Structures and Systems
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• v.22 no.2
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• pp.139-150
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• 2018

A variable electromotive-force generator (VEG), which is a modified generator with an adjustable overlap between the rotor and the stator, is proposed to expand the operational range of a regular generator through a simple and robust active control strategy. It has a broad range of applications in hybrid vehicles, wind turbines, water turbines, and similar technologies. A mathematical model of the VEG is developed, and a novel prototype is designed and fabricated. The performance of the VEG with an active control system, which adjusts the overlap ratio based on the desired output power at different rotor speeds for a specific application, is theoretically and experimentally studied. The results show that reducing the overlap between the rotor and the stator of the generator results in reduced torque loss of the generator and an increased rotational speed of the generator rotor. A VEG can improve the fuel efficiency of hybrid vehicles; it can also expand operational ranges of wind turbines and water turbines and harness more power.

• Polymer(Korea)
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• v.33 no.4
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• pp.333-341
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• 2009

Polypropylene (PP)/functionalized multiwalled carbon nanotube (F-MWNT) nanocomposites were prepared by using solution intercalation method with different F-MWNT loads. The PP composite films, which contain dodecanol-MWNT (DDO-MWNT) or dodecylamine-MWNT (DDA-MWNT) as reinforcing additive, were evaluated by thermomechanical properties, morphology, electrical conductivity and gas permeability. The images from electron microscopy (SEM and TEM) showed that F-MWNTs were homogeneously dispersed in PP matrix, while they were agglomerated in some other part. The addition of F-MWNT could improve thermomechanical properties of the films. The maximum enhancement was observed at 2 wt% F-MWNT. DDO-MWNT was more effective than DDA-MWNT for both tensile modulus and optical transparency of the films.