• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.794-801
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• 2021

This study examined the mechanical strength and corrosion resistance of a dissimilar joint with an aluminum alloy and steel by resistance element spot welding. SPFC980 steels and Al5052 alloys were applied as the base materials. S20C steels were assembled on Al5052 for the riveting element before the electric resistance welding process. The SPFC980-S20C riveted Al5052 was welded at a 6.5 kA current and 250 kgf/㎠. As a result, the engraved S20C elements formed unstable nuggets after the spot welding processes. In contrast, in the embossed S20C elements, exceptional mechanical properties, such as robust corrosion resistance and fatigue resistance, were obtained by structurally sound joints. The correlation between the microstructure and mechanical properties were examined by microstructural investigations and FEM simulations. The corrosion reliability of element spot-welded SPFC980-Al5052 dissimilar joints was investigated systematically.

• Journal of Sensor Science and Technology
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• v.21 no.3
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• pp.172-179
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• 2012

This paper presents the design and analysis of a vibration-driven electromagnetic energy harvester that uses a multi-pole magnet. The physical backgrounds of the vibration electromagnetic energy harvester are reported, and an ANSYS finite element analysis simulation has been used to determine the different alignments of the magnetic pole array with their flux lines and density. The basic working principles for a single and multi-pole magnet are illustrated and the proposed harvester has been presented in a schematic diagram. Mechanical parameters such as input frequency, maximum displacement, number of coil turns, and load resistance have been analyzed to obtain an optimized output power for the harvester through theoretical study. The paper reports a maximum of 1.005 mW of power with a load resistance of $1.9k{\Omega}$ for 5 magnets with 450 coil turns.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1272-1274
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• 2013

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.175-177
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• 2007

An analysis on a passive current sharing characteristics of a multi-phase synchronous buck converter is presented. The passive current sharing method is simple but its characteristics depend on the converter equivalent resistance and PWM uniformity. In this paper, the load sharing and power consumption of the passive current sharing system for the converter equivalent resistance and duty ratio inequalities are investigated through the simulation and experiment.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.413-421
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• 2011

The main objective of this study was to develop the multi-resistance lines to insects(brown planthopper; BPH, rice green leafhopper; GRH) and disease(blast; BL, bacterial blight; BB and rice stripe virus disease;RSV) with good grain quality and plant type by combining conventional breeding and marker assisted selection(MAS) and to eliminate the linkage drag effects between Bph1 gene and culm length, we conducted MAS of Bph1 gene in advanced backcross and double cross progenies. 'Nampyeong', 'Junam' and 'Milyang220' were used as the parent in this study. 'Milyang220' was used as the donor of brown planthopper resistance gene Bph1 with tall culm length. Two backcross progenies were developed using two recipients 'Nampyeong' carrying GRH resistance gene Grh3(t) with good grain appearance and 'Junam' harboring bacterial blight resistance gene Xa3 with short culm length. Two $BC_1$ generations were resulted from the backcrossing of the $F_1$ plants with recurrent parents 'Nampyeong' and 'Junam'. The second rounds of backcrossing($BC_2$) were derived from the cross of selected resistant $BC_1F_1$ plants based on heterozygous genotype of RM28493 linked to Bph1 gene. The double crossed population was constructed from the cross of between each heterozygous $BC_2F_1$ plants at RM28493 locus of '$Nampyeong^*3$ / Milyang220' and '$Junam^*3$ / Milyang220'., The homozygous alleles in Bph1 gene were selected using co-dominant DNA marker RM28493 in double crossed population. Eighty-five lines with multi-resistance to BL, BB, RSV, GRH and BPH were selected by bio-assay and MAS in generation of double crossing. The culm length, head rice ratio and yield of the selected multi resistance lines was ranged from 71 to 88 cm, from 51 to 93%, from 449 to 629 kg/10a. respectively. We can select a promising multi resistance line similar with 'Nampyeong' of major agronomic traits such as culm legnth, head rice ratio and yield. It was designated as Milyang265. Finally this study was developed the multi resistant varieties against to insects and diseases with the good grain quality 'Milyang265' by the advanced backcross and double cross combining MAS and it can be used as genetic resources of multi-resistance to insect and diseases in rice breeding programs.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.39-48
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• 2016

In this paper, we propose thermal resistance compact model of FinFET structure that has hexagon shaped source/drain. The heating effect and thermal properties were increased by reduced size of the device, and thermal resistance is an important factor to analyze the effect and the properties. The heat source and each contact that is moved heat out were set up in transistor, and domain is divided by the heat source and the four parts of contacts : source, drain, gate, substrate. Each contact thermal resistance model is subdivided as a easily interpretable structure by analyzing the temperature and heat flow of the TCAD simulation results. The domains are modeled based on an integration or conformal mapping method through the structure parameters according to its structure. First modeled by analyzing the thermal resistance to a single fin, and applying the change in the parameter of the channel increases to improve the accuracy of the thermal resistance model of the multi-fin/ finger. The proposed thermal resistance model was compared to the thermal resistance by analyzing results of the 3D Technology CAD simulations, and the proposed total thermal resistance model has an error of 3 % less in single and multi-finl. The proposed thermal resistance model can predict the thermal resistance due to the increase of the fin / finger, and the circuit characteristics can be improved by calculating the self-heating effect and thermal characterization.

• Progress in Superconductivity and Cryogenics
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• v.6 no.2
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• pp.20-24
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• 2004

Bi-2223 wire, the first-generation high temperature superconducting (HTS) wire, was successfully commercialized and various electrical machinery and equipment are actively being developed in many countries. Because its critical current is too small to realize the lossless conducting part of electric power system with a HTS wire, multi-HTS paths are used to enlarge the critical current of HTS system. Though the resistance generated in HTS wire by transport current is very small, the difference of it in multi-path is the additional reason which causes the non-uniform current sharing in multi-HTS path except the well known reason, the difference of inductance between each path. In this paper, experimental research on current sharing of multi-strand and multi-stacked HTS wire was implemented. The whole critical current of multi-HTS paths is not equal to sum of critical current of each path because of non-uniform current sharing occurred in this paths. It was verified experimentally that Bi-2223 wires have different resistance generated by same transport current even if they was manufactured in same progress of work. Current sharing phenomenon was affected by difference of resistance and self and mutual inductance.

• Journal of the Society of Disaster Information
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• v.3 no.2
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• pp.147-169
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• 2007

This study investigates the reinforcing effects of the Multi-bar Spring nails with respect to the conventional Soil-nails in artificial slopes. Based on wide experience related to design and construction, soil nails have been widely applied to reinforce slope in the world. Multi-bar spring nails are one of the improved soil nailing methods. These method maximizes bending, shearing, pull-out resistance for those multi-nails, not unit nail, that are inserted in the borehole using special spacer at regular intervals. In addition, because cutting plane is confined effect resulting from a pressured plate at the end of the nails with compression spring equipment, slope stability is secured using MS-nailing method. Analyzing bending, pull-out, shearing condition of MS-nail, it was examined throughly elastic region, load transfer capacity, reinforcing effect on cutting plate of MS-nails. In addition, Pilot and laboratory tests, numerical analysis were carried out to verify the superiority of MS-nailing method. In case, MS nailing method is applied to reinforce artificial slope, it was analyzed that bending, pull-out, shearing resistance was increased more than existing nailing method was applied. In this study, it was shown that surface failure was more or less prevented using MS-nailing method, confining effect on cutting plane using spring stuck to flexible equipment.

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1067-1073
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• 2006

Cisplatin, a platinum coordinated complex, is a widely used antineoplastic agent for the treatment of metastatic tumors of the testis, metastatic ovarian tumors, lung cancer, advanced bladder cancer and many other solid tumors. The cytotoxic action of the drug is often thought to be associated with its ability to bind DNA to form cisplatin-DNA adducts. The development of resistance to cisplatin during treatment is common and constitutes a major obstacle to the cure of sensitive tumors. Although to understand the clinically relevant mechanisms of resistance, many studies have been aimed at clarifying the biochemical/molecular alterations of cisplatin-resistance cells, these studies did not conclusively identify the basis of cellular resistance to cisplatin. In this review, cisplatin resistance was discussed in terms of the relevant transporters, such as copper transporters (CTRs), organic cation transporters (OCTs) and multi-drug resistance related transporters (MDRs). These transporters seem to be contributed to cisplatin resistance through the reduction of drug accumulation in the cell. Better understanding the mechanism of cisplatin resistance associated with transporters will provide the useful informations for overcoming the cisplatin resistance.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2619-2623
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• 2014

Aim: To investigate signaling pathways for reversal of EGF-mediated multi-drug resistance (MDR) in hepatocellular carcinoma (HCC) models. Materials and Methods: HCC MDR cell strain HepG2/adriamycin (ADM) and SMMC7721/ADM models were established using a method of exposure to medium with ADM between low and high concentration with gradually increasing concentration. Drug sensitivity and reversal of multi-drug resistance by EGF were determined and the cell cycle distribution and apoptosis were analyzed by flow cytometry. Phosphorylation of ERK1, ERK2, ERK5 and expression of Bim were detected by Western blotting. Results: The results showed that HepG2/ADM and SMMC7721/ADM cells were resistant not only to ADM, but also to multiple anticancer drugs. When used alone, EGF had no anti-tumor activity in HepG2/ADM and SMMC7721/ADM cells in vitro, while it increased the cytotoxicity of ADM. EGF induced cell apoptosis and G0/G1 phase cell cycle arrest in HepG2/ADM And SMMC7721/ADM cells, while enhancing activity of p-ERKs and up-regulated expression of BimEL. Conclusions: EGF might enhance the chemosensitivity of HepG2/ADM and SMMC7721/ADM cells via up-regulating p-ERKs and BimEL protein.