• Journal of the Korean Ceramic Society
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• v.40 no.1
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• pp.37-45
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• 2003

The dielectric and sintering characteristics of composites made by substituting Ca ion to Ba-site and Zr ion to Ti site in $(Ba{1-x}Ca_x)(Ti{0.96-yZr_ySn_{0.04})O_3$ $(0.15{\leq}x{\leq}0.20,\;0.09{\leq}y{\leq}0.14)$ were investigated. As the content of Ca was more than 15 mol%, composite was formed by precipitating the second phase whose main element was $CaTiO_3$ and the fraction of the second phase was increased. The curie temperature of composites was depended on Ca concentration, $-1.7^{\circ}C$ per mol% and the maximum dielectric constant of composite was decreased by the rate of 200/mol%. The substitution of Zr ion decreased the curie temperature by the rate of $10^{\circ}C$ per mol% and the maximum dielectric constant was decreased by 217/mol% due to the increase of diffuse phase transition. The density and insulation breakdown characteristics were improved by suppressing the abnormal grain growth due to the increase of second phase. We developed the composition of Y5U (EIA standard) condenser which had high breakdown voltage and dielectric constant by controlling diffuse phase transition by the addition of Zr ion into composite.

• The Journal of the Korea Contents Association
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• v.4 no.4
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• pp.33-43
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• 2004

In this paper, a traffic trend analysis based SNMP algorithm is proposed for improving the problem of existing traffic analysis using SNMP. The existing traffic analysis method has a vulnerability that is taken much time In analyzing by using a threshold and not detected a harmful traffic at the point of transition. The method that is proposed in this paper can solve the problems that the existing method had, simultaneously using traffic trend analysis of the day, traffic trend analysis happening in each protocol and MIB object analysis responding to attacks instead of using the threshold. The algorithm proposed in this paper will analyze harmful traffic more quickly and more precisely; hence it can reduce the damage made by traffic flooding attacks. When traffic happens, it can detect the abnormality through the three analysis methods previously mentioned. After that, if abnormal traffic overlaps in at least two of the three methods, we can consider it as harmful traffic. The proposed algorithm will analyze harmful traffic more quickly and more precisely; hence it can reduce the damage made by traffic flooding attacks.

• Journal of IKEEE
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• v.8 no.1 s.14
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• pp.12-21
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• 2004

Error control is one of major concerns in many electronic systems. Experience shows that most malfunctions during system operation are caused by transient faults, which often mean abnormal signal delays that may result in violations of circuit element timing constraints. This paper presents a novel CMOS-based concurrent timing error detector that makes a flip-flop to sense and then signal whether its data has been potentially corrupted or not by a setup or hold timing violation. Designed circuit performs a quiescent supply current evaluation to determine timing violation from the input changes in relation to a clock edge. If the input is too close to the clock time, the resulting switching transient current in the detection circuit exceeds a reference threshold at the instant of the clock transition and an error is flagged. The circuit is designed with a $0.25{\mu}m$ standard CMOS technology at a 2.5 V supply voltage. The validity and effectiveness are verified through the HSPICE simulation. The simulation results in this paper shows that designed circuit can be used to detect setup and hold time violations effectively in clocked circuit element.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1482-1504
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• 2007

An electrical railway system uses high voltage system for train traction and low voltage system for train control. Railway systems are broadly distributed across mountains, sea sides and cities. Electrical accidents provoke the death and injury of a human being and the damage of the equipment by the overcurrent due to the catenary dropping and by the overvoltage due to lightning. Grounding systems are adopted for the protections of the system from the overcurrent and the overvoltage. Isolation grounding for each system can be easily installed. However, the closed circuits between grounding systems can be occurred. The currents flow through the closed circuits cause the abnormal operation of the system. To overcome the problem of the isolation grounding, the equipotential bonding is usually adopted. The equipotential bonding should have very small grounding resistance. In this paper, we showed the transition from the isolation grounding system to the common grounding system and presented the comparison and the analysis of two grounding systems by simulation. In addition, we proposed the direction for a new grounding system of electric railway.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2000.11a
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• pp.91-97
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• 2000

The conventional model did not take momentum conservation into consideration when the electron absorbs and emits the photons. II-ray provides momentum conservations on any directions of the entering photons, and also the electrons have radial momentum conservations and fully elastic bouncing between two atoms, in the new atom model. Conventional atom model must be criticized on the following four points. (1) Natural motions between positive and negative entities are not circular motions but linear going and returning ones, for examples sexual motion, tidal motion, day and night etc. Because the radius of hydrogen atom's electron orbit is the order of 10$^{-11}$ m and the radia of the nucleons in the nucleus are the order of 10$^{-l4}$m and then the converging n-gamma rays to the nucleus have so great circular momentum, the electron can not have a circular motion. We can say without doubt that any elementary mass particle can have only linear motion because of the n-rays' hindrances, near the nucleus. (2) Potential energy generation was neglected when electron changes its orbit from outer one to inner one. The h v is the kinetic energy of the photo-electron. The total energy difference between orbits comprises kinetic and potential energies. (3) The structure of the space must be taken into consideration because the properties of the electron do not change during the transition from outer orbit to inner one even though it produces photon. (4) Total energy conservation law applies to the energy flow between mind and matter because we daily experiences a interconnection between mind and body. An understanding of the mechanisms responsible for the control of normal proliferation and differentiation of the various cell types which make up the human body will undoubtedly allow a greater insight into the abnormal growth of cells, A large body of biochemical evidence was eventually used to generate a receptor model with an external ligand binding domain linked through a single trans-membrane domain to the cytoplasmic tyrosine kinase and autophosphory-lation domains. The ligand induced conformational change in the external domain generates either a push-pull or rotational signal which is transduced from the outside to the inside of cell.l.ell.

• Journal of the Korean Vacuum Society
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• v.16 no.4
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• pp.298-304
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• 2007

We have studied the effect of $N_2$ flow rate on the structural and optical properties of GaN nanorods grown on (111) Si substrates by radio-frequency plasma-assisted molecular-beam epitaxy. The hexagonal shape nanorods with lateral diameters from 80 to 190 nm with increasing $N_2$ flow rate from 1.1 to 2.0 sccm are obtained. However, the ratio of length (thickness) and compact region increases with increasing $N_2$ flow rate up to 1.7 sccm and then saturate. From the photoluminescence, free exciton transition is clearly observed for GaN nanorods with low $N_2$ flow rate. And the PL peak energies are blue-shifted with decreasing diameter of the GaN nanorods due to size effect. Temperature-dependent photoluminescence spectra for the nanorods with $N_2$ flow rate of 1.7 sccm show an abnormal behavior like "S-shape" with increasing temperature.

• Development and Reproduction
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• v.16 no.1
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• pp.59-67
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• 2012

Previously, we found that $Zap70$ (Zeta-chain-associated protein kinase) expressed in the mouse oocytes and played significant role in completion of meiosis specifically at MI-MII (metaphase I-II) transition. Microinjection of $Zap70$ dsRNA into the cytoplasm of germinal vesicle oocyte resulted in MI arrest, and exhibited abnormalities in their spindles and chromosome configurations. The purpose of this study was to determine the mechanisms of action of $Zap70$ in oocyte maturation by evaluating downstream signal networking after $Zap70$ RNAi (RNA interference). The probe hybridization and data analysis were used by Affymetrix Gene Chip Mouse Genome 430 2.0 array and GenPlex 3.0 (ISTECH, Korea) software, respectively. Total 1,152 genes were up (n=366) and down (n=786) regulated after $Zap70$ RNAi. Among those genes changed, we confirmed the expressional changes of the genes involved in the regulation of actin cytoskeleton and MAPK (mitogen-activated protein kinase) signaling pathway, since the phenotypes of $Zap70$ RNAi in oocytes were found in the changes in the chromosome separation and spindle structures. We confirmed the changes in gene expression in the actin skeletal system as well as in the MAPK signaling pathway, and concluded that these changes are main cause of the aberrant chromosome arrangement and abnormal spindles after $Zap70$ RNAi.

• Journal of Integrative Natural Science
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• v.4 no.2
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• pp.113-120
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• 2011

Brassinosteroids (BRs) are plant steroid hormones that play essential roles in growth and development. Mutations in BR-signaling pathways cause defective in growth and development like dwarfism, male sterility, abnormal vascular development and photomorphogenesis. Transition from vegetative to reproductive growth is a critical phase change in the development of a flowering plant. In a screen of activation-tagged Arabidopsis, we identified a mutant named abz126 that displayed longer hypocotyls when grown in the dark on MS media containing brassinazole (Brz), an inhibitor of BRs biosynthesis. We have cloned the mutant locus using adapter ligation PCR walking and identified that a single T-DNA had been integrated into the ninth exon of the GIGANTEA (GI) gene, involved in controling flowering time. This insertion resulted in loss-of-function of the GI gene and caused the following phenotypes: long petioles, tall plant height, many rosette leaves and late flowering. RT-PCR assays on abz126 mutant showed that the T-DNA insertion in GIGANTEA led to the loss of mRNA expression of the GI gene. In the hormone dose response assay, abz126 mutant showed: 1) an insensitivity to paclobutrazole (PAC), 2) an altered response with 6-benzylaminopurine (BAP) and 3) insensitive to Brassinolide (BL). Based on these results, we propose that the late flowering and tall phenotypes displayed by the abz126 mutant are caused by a loss-of-function of the GI gene associated with brassinosteroid hormone signaling.

• Journal of the Korean housing association
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• v.21 no.4
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• pp.51-58
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• 2010

In the modernization process of the city, urbanization raised a variety of social issues. Urbanization brought noticeable changes in dwelling patterns, such as drastic changes in the housing lifestyle, that revolved around the metropolitan areas of Seoul and Busan etc. before and after the expansion of economic growth. Especially in 1985, when 23.8% of the country's population was concentrated in Seoul, the imbalance of housing supply and demand caused a vast range of housing shortage. The shortage, that resulted from public sector mishandling of natural housing demand, lead to the occurrence of private sector rental housing. The occurrence of this abnormal rental housing supply, became a major cause of Korea's typical lease system called 'Co-dwelling', where the leaseholder and tenant physically lives in the same residence. The leaseholder and tenant's 'Co-dwelling' started from partial renting of traditional Korean-style housing and transformed with the transition of dwelling form and time. However, after 1985, legalization of multi-family housing, Korean rental housing started to be planned in the beginning of it's housing construction and to be produced as an independent space with separate circulation. Also in terms of facility, it changed from partial renting of a space within the residence to an assembly of small individual spaces. However, the background of this deep-rooted 'Co-dwelling' lease system, in different forms and periods of residence, is still based on the lack of public sector rental housing supply and private sector supply of rental space to utilize extra space, 'Jeonsei' payment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.9
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• pp.766-771
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• 2009

Lead-free $0.94(Na_{0.5}K_{0.5})NbO_3$-0.06Ba$(Ti_{0.9}Sn_{0.1})O_3$ [0.94NKN-0.06BTS] ceramics doped with 1 mol% $MnO_2$ were synthesized by a conventional solid state method. The phase transitional behavior and piezoelectric properties of the ceramics sintered at various temperatures were investigated. The 0.94NKN-0.06BTS ceramics sintered at $1050^{\circ}C$, having morphotropic phase boundary of orthorhombic and tetragonal phases, exhibited a microstructure with abnormal grain growth. A diffused phase transition behavior for all the specimens was verified as high degree of diffuseness (${\gamma}$) values from 1.45 to 1.79. A high piezoelectric constant of $d_{33}=256$ pC/N and a satisfactory electromechanical coupling factor of $k_p=42%$ were obtained for the relatively dense 0.94NKN-0.06BTS ceramics sintered at $1050^{\circ}C$.