표면곡률을 이용한 물체의 형상특징추출

조동욱,김지영,박웅규,윤상균,이성석,김태우 西原大學校 1992 西原大學 論文集 Vol.29 No.-

In this paper, a new shape feature extraction method of the objects using surface curvatures is described. First, the values of the H & K are calculated from range data as given input. Then objects are assigned in the form of 8 primitives by the signs of the H & K values. But existing methods have the difficulties with the complex object. Therefore, We propose the method for the complex primitives such as cone ridge and cone valley. Finally, the effectiveness of this paper is demonstrated by several experiment.

Transport Properties of Magnetic Tunnel Junctions Comprising NiFeSiB/CoFeB Hybrid Free Layers

Ji Ung Cho,Do Kyun Kim,Tan, R.P.,Isogami, S.,Tsunoda, M.,Takahashi, M.,Young Keun Kim IEEE 2009 IEEE transactions on magnetics Vol.45 No.6

<P>We report on the magneto-transport measurements of MgO magnetic tunnel junctions (MTJs) composed of NiFeSiB/CoFeB as the free layer for two different structures (top-type and bottom-type pinning). The magneto-transport properties of these MTJs were investigated by varying the thickness of the amorphous NiFeSiB layer for a fixed CoFeB thickness. The tunnel magnetoresistance (TMR), measured in both type of structures, exhibit the same or a higher amplitude (up to 230% measured at room temperature in the case of top-type device), comparing to the case of a single CoFeB free layer. These results suggest that hybrids free layers can be used as good candidates for MTJs with reduced saturation magnetization while keeping a high TMR ratio.</P>

Magnetoresistance Variation of Magnetic Tunnel Junctions with NiFeSiB/CoFeB Free Layers Depending on MgO Tunnel Barrier Thickness

Ji Ung Cho,Do Kyun Kim,Tian Xing Wang,Isogami, S.,Tsunoda, M.,Takahashi, M.,Young Keun Kim IEEE 2008 IEEE transactions on magnetics Vol.44 No.11

<P>We developed NiFeSiB/CoFeB hybrid free-layers for magnetic tunnel junctions (MTJs) with MgO tunnel barrier layers. These junctions show tunneling magnetoresistance (TMR) ratios and resistance-area (RA) values ranging from 118-209% and 36-2380 Omega mum<SUP>2</SUP> , respectively, obtained at room temperature. Compared to the CoFeB single free-layer case, the NiFeSiB/CoFeB hybrid free-layer approach has the advantage of lowering saturation magnetization. The low magnetization material would be effective to decrease the switching current in spin transfer torque (STT) switching. The experimental results show that the RA value depends not only on the thickness of the MgO barrier but also on the structure of the free layer used. Tunable in the TMR ratio and RA value using the design of the hybrid free-layer, our hybrid free-layered MTJs demonstrate a desirable lower RA value but a similar TMR ratio in comparison to the CoFeB free-layered ones.</P>

Transport Properties of Magnetic Tunnel Junctions Comprising NiFeSiB/CoFeB Hybrid Free Layers

Ji Ung Cho,Do Kyun Kim,Tian Xian Wang,Shinji Isogami,Masakiyo Tsunoda,Migaku Takahashi,Young Keun Kim 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Impact of Na2MoO4 nanolayers autogenously formed on tunnel-type Na0.44MnO2

Choi, Ji Ung,Jo, Jae Hyeon,Jo, Chang-Heum,Cho, Min Kyoung,Park, Yun Ji,Jin, Yongcheng,Yashiro, Hitoshi,Myung, Seung-Taek The Royal Society of Chemistry 2019 Journal of Materials Chemistry A Vol.7 No.22

<P>We propose the coating of tunnel-type Na0.44MnO2 cathode materials with multi-functional Na2MoO4 nanolayers for use in rechargeable sodium batteries. Electro-conducting Na2MoO4 nanolayers (electrical conductivity of ∼10<SUP>3</SUP> S cm<SUP>−1</SUP>) are autogenously formed on the surface of Na0.44MnO2 particles through the reaction of (NH4)2MoO4 with surface sodium residues <I>via</I> melt impregnation at 350 °C. The Na2MoO4-modified Na0.44MnO2 electrode delivers discharge capacities of ∼120.4 mA h (g-oxide)<SUP>−1</SUP> at 0.1C (12 mA g<SUP>−1</SUP>) and 79.7 mA h g<SUP>−1</SUP> at 50C (6 A g<SUP>−1</SUP>). Moreover, with continuous cycling at a rate of 60C (7.2 A g<SUP>−1</SUP>), the Na2MoO4-coated Na0.44MnO2 electrode is able to retain a capacity of approximately 56 mA h g<SUP>−1</SUP> without notable capacity fading for 1000 cycles. This achievement is attributed to the presence of Na2MoO4 on the active materials, which facilitates electron transfer during electrochemical reaction in Na cells. More interestingly, Na2MnO4 undergoes two-step HF scavenging to finally form MoO3−xF2x layers <I>via</I> an intermediate of H2MoO4 (MoO3·H2O) layers. The surface layers protect the active materials from HF attack in the electrolyte. These multi-functional effects of the Na2MoO4 and MoO3−xF2x surface layers are responsible for the long-term cycle stability of the cathode material for ultra-high-rate sodium storage applications.</P>

Identification of quantitative trait loci related to grain filling under low temperature condition

Jong-Min Jeong,Ung-Jo Hyun,Ji-Ung Jeung,Kyung-Ho Kang,Young-Chan Cho,Bo-Kyeong Kim 한국육종학회 2015 한국육종학회 심포지엄 Vol.2015 No.07

Low temperature is a major abiotic stress that adversely affects rice production in rice cultivation regions of the world. Low temperature during the rice growing season, can inhibit growth and development at any development stage, from germination to grain filling. Among the rice growth stage, reproductive stage was known as the most sensitive to low temperature, causing sterile grain and lead yield loss. However, low temperature during the grain filling stage also, may cause delay and incomplete grain maturation. In this study QTL analysis were performed to identify the QTLs associated with percent of grain filling under low temperature condition during the grain filling stage. A 139 RIL derived from a cross between ‘Milyang23’ (Tong-il, cold susceptible) and ‘Gihobyeo’(Japonica, cold tolerance) were exposed to air and water of 17℃ at the same time for 14 days during the grain filling stage. One significant QTL associated to percent of grain filling was detected on chromosome 7. This QTL could explain 14.7% of the phenotypic variance for percent of grain filling. We have the plan to confirm the detected QTL through further study.

PCR-based allele specific markers for bacterial blight resistance gene in rice.

Yeon-Jae Hur,Jong-Hee Lee,Ji-Ung Jeung,Ji-Yoon Lee,Jun-Hyun Cho,Hyun-Jin Park,You-Chun Song,Myung-Gyu Oh,Un-Sang Yeo,Choon-Woo Lee,Min-Hee Nam 한국육종학회 2012 한국육종학회 심포지엄 Vol.2012 No.07

The use of functional markers, it is expected to make direct identification about genetic diversity at DNA level and overcome the problem of recombination /linkage. These markers can be used to identify interesting alleles in a breeding program and indirectly select for the trait, saving money, time and labor. Bacterial blight of rice caused by Xanthomonas oryzaepv. Oryzae is a destructive disease in rice production worldwide. No bactericide is effective to control the bacterial blight disease yet. Xa3, which is a gene conferring resistance to BB of the rice plant has been previously characterized by map-based cloning. We have cloned and sequenced the Xa3/xa3 gene in Korean cultivar, Hwayoung, Ilmi and Goun with gene specific primers. Our work detected polymorphisms and PCR-based allele specific SNP markers were developed. Susceptible or resistant individuals from an F2 population developed from across between Milyang244 and Ilmi, Korean germplasms and near isogenic lines carrying BB resistance genes were screened with allele specific markers. We found that the genotype completely matched their phenotype to BB using ASP-primers. These markers could be effective to marker-assisted selection for the Xa3 gene in rice breeding programs.

Molecular analysis of T-DNA insertion mutant population for transgenic rice plants

Hyemin Lim,A-Ram Kim,Jung-Il Cho,Hyeon-So Ji,Ung-Han Yoon,Tae-Ho Kim,Gang-Seob Lee 한국육종학회 2014 한국육종학회 심포지엄 Vol.2014 No.07

We have generated 383 independent transgenic lines for genetically modified (GM) rice that contained GPD, UtrCSP, BrTSR15 and BrTSR53 genes overexpression constructs under the control of the constitutive CaMV 35S promoter. TaqMan copy number assay was determined inserted T-DNA copy number. Also FSTs analysis was isolated from 203 single copy T-DNA lines of transgenic plants and sequence mapped to the rice chromosomes. In analyzing single copy lines, we identified 95 FSTs, among which 37 (38.9%) were integrated into genic regions and 58 (61.1%) into intergenic regions. About 27 homozygous lines were obtained through multi-generations of planting, resistance screening and TaqMan copy number assay. To investigate the transgene expression patterns, quantitative real-time PCR analysis was performed using total RNAs from leaf tissue of single copy, intergenic region of T-DNA insertion and homozygous T2 plants. The mRNA expression levels of the examined transgenic rice were significantly increased in all of the transgenic plants. In addition, myc-tagged 35S::BrTSR15 and 35S::BrTSR53 transgenic plants were displayed higher levels of transgene protein than WT plants. These results may be useful for producing of large-scale transgenic plants or T-DNA inserted mutants in rice.

Effectiveness of marker-assisted backcrossing breeding for biotic resistance in rice

Jung-Pil Suh,Kshirod K. Jena,Young-Chan Cho,Ji-Ung Jeung,Yong-Jae Won,Im-Soo Choi,Jeom-Ho Lee,Myeong-Ki Kim,Chung-Kon Kim 한국육종학회 2013 한국육종학회 심포지엄 Vol.2013 No.07

The transfer of a biotic resistance gene from indica rice cultivars into japonica cultivars by conventional breeding methods often difficult due to high sterility of the progenies, poor plant type, and linkage drag. Molecular markers provide opportunities to map resistance genes and accelerate the application of marker-assisted backcross(MAB) breeding through the precise transfer of target genomic regions into the recurrent parent. The basis of MAB breeding is to transfer a specific gene/allele of the donor parent into the recurrent parent genome while selecting against donor introgressions across the rest of the genome. The effectiveness of MAB breeding depends on the availability of closely linked DNA markers for the target locus, the size of the population, the number of backcrosses and the position and number of markers for background selection. We have successfully developed Bph18 version of the commercially cultivated japonica elite cultivar by using MAB and incorporating the resistance gene Bph18 that conferred enhanced resistance to BPH. MAB breeding provides a new opportunity for the selective transfer of biotic resistance genes into elite indica rice cultivars devoid of linkage drag. In additon, molecular markers precisely estimate the introgression of chromosome segments from donor parents and can speed up the recipient genome recovery via background selection.

Tunnel-type β-FeOOH cathode material for high rate sodium storage via a new conversion reaction

Cho, Min Kyoung,Jo, Jae Hyeon,Choi, Ji Ung,Kim, Jongsoon,Yashiro, Hitoshi,Yuan, Shuai,Shi, Liyi,Sun, Yang-Kook,Myung, Seung-Taek Elsevier 2017 Nano energy Vol.41 No.-

<P><B>Abstract</B></P> <P>We have investigated a tunnel-type β-FeOOH cathode material for rapid sodium storage. Rietveld refinement of the X-ray diffraction (XRD) data obtained for β-FeOOH indicated that the structure was stabilized into [2 × 2] hollandite tunnel structure, and the adhesion of the β-FeOOH onto carbon nanotubes (CNTs) led to a high electrical conductivity of 3Scm<SUP>−1</SUP>. As a result, the β-FeOOH/CNTs composite electrode showed excellent electrode performance, with a discharge capacity of 205 mAh g<SUP>−1</SUP> and a coulombic efficiency of 88.5% in the voltage range of 1.1–4V during the first cycle, 131 mAh g<SUP>−1</SUP> after 200 cycles, and a capacity retention of 70% over 300 cycles at 10C (1920mAg<SUP>−1</SUP>). Based on the XRD, X-ray absorption, and time-of-flight secondary-ion mass spectroscopy results, we suggest a new conversion mechanism for the β-FeOOH cathode material in Na cells, namely, FeOOH + Na<SUP>+</SUP> + e<SUP>-</SUP> → FeO + NaOH. This conversion reaction produces NaOH as a byproduct, and the reaction is fairly reversible even at 10 C-rates.</P> <P><B>Highlights</B></P> <P> <UL> <LI> β-FeOOH/CNTs composite is suggested as an cathode material for Na-ion batteries. </LI> <LI> β-FeOOH/CNTs composite is activated by a new conversion reaction via Fe<SUP>3+/2+</SUP> redox. </LI> <LI> β-FeOOH/CNTs composite shows a high electric conductivity, 3Scm<SUP>−1</SUP>. </LI> <LI> β-FeOOH/CNTs composite is fairly reversible at high rates for a long term. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>We report on tunnel type β-FeOOH nano-stick particles embedded in carbon nanotubes. The β-FeOOH/CNTs composite represents rapid sodium storage capability via a new conversion reaction, which is fairly reversible at high rates for a long term.</P> <P>[DISPLAY OMISSION]</P>