• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1195-1198
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• 2013

Nickel hexacyanoferrate supported palladium nanoparticles (Pd-NiHCF NPs) were synthesized and studied for oxygen reduction reactions in direct methanol fuel cell. The NiHCF support was readily synthesized by a comixing of $Ni(OCOCH_3)_2$ and equimolar $K_3[Fe(CN)_6]$ solution into DI water under rigorous stirring. After the preparation of NiHCF support, Pd NPs were loaded on NiHCF via L-ascorbic acid reduction method at $80^{\circ}C$. Pd-NiHCF NPs were electrochemically active for oxygen reduction reaction in 0.1 M $HClO_4$ solution. X-ray absorption near edge structure analysis was conducted to measure the white line intensity of Pd-NiHCF to verify the OH adsorption. As a comparison, carbon supported Pd NPs exhibited same white line intensity. This study provides a general synthetic approach to easily load Pd NPs on porous coordination polymers such as NiHCF and can provide further light to load Pd based alloy NPs on NiHCF framework.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.4 no.1
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• pp.23-36
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• 1995

The purpose of this artic1e is to compare soft tissue profiles between Korean adults with normal occ1usion and malocclusin and to identify the differences between them. The subjects of this cephalometric study were 40 males with normal occlusion(Group 1), 27 females with normal occlusion(Group 2), 28 adults with Angle's Class II malocclusion(Group 3) and 41 adults with Angle's Class III malocclusion(Group 4). The results of this study were as follows ; 1) People with Angle's Class II malocclusion had tendency to have more labial tipping of lower teeth than people with normal occ1usion. Through NOA angle measurement, it was determined that people with Angle's Class II malocclusion had more protruding midface than people with normal occlusion and people with Angle's Class III malocclusion had retruding midface. 2) Through Powell's esthetic triangle analysis, it was determined that people with Angle's Class II malocclusion had retruding chin and protruding nose. 3) No significant differences between people with normal occlusion and maloclusion could be identified by measuring soft tissue profile angle basis of S-NS plane. 4) There were significant differences between groups with normal occlusion and malocclusion by measuring Facial convexity angle(Significance level 99%). 5) By measuring the distance between each landmark basis of N-Pog plane, People with Angle's Class II malocclusion were identified as having more protruding midface, but there were no significant differences between people with normal occlusion and Angle's Class III malocclusion. 6) By measuring the vertical dimension of the face, it was determined that the lower facial height was higher than the upper facial height in all groups, particularly in group with Angle's Class III malocclusion. 7) By measuring the lips basis of E-line and S-line, it was determined that people with Angle's Class III malocclusion had more, protruding lower lips than people with normal occlusion, while people with normal occlusion, while people with Angle's Class II malocclusion had more protruding upper lips. By measuring the distance between the superior sulcus and inferior sulcus basis of H-line, people with Angle's Class II malocclusion had thicker upper lips than the other's.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.4
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• pp.331-338
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• 1992

The application of Connectionist expert system using neural network to fault diagnosis of power system is presented and compared with rule-based expert system. Also, the merits of Connectionist model using neural network is presented. In this paper, the neural network for fault diagnosis is hierarchically composed by 3 neural network classes. The whole power system is divided into subsystems, the neural networks (Class II) which take charge of each subsystem and the neural network (Class III) which connects subsystems are composed. Every section of power system is classified into one of the typical sections which can be applied with same diagnosis rules, as line-section, bus-section, transformer-section. For each typical section, only one neural network (Class I) is composed. As the proposed model has hierarchical structure, the great reduction of learning structure is achieved. With parallel distributed processing, we show the possibility of on-line fault diagnosis.

• Communications of the Korean Mathematical Society
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• v.11 no.1
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• pp.259-263
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• 1996

Let G be a topological group and X a G space. For a given nonequivariant vector bundle over X there does not always exist a G equivariant vector bundle structure. In this paper we find some sufficient conditions for nonequivariant real line bundles to have G equivariant vector bundle structures.

• Journal of The Korean Association of Information Education
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• v.15 no.4
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• pp.603-612
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• 2011

This study suggested an educational curriculum(12 class periods) in order for higher level elementary school students to learn programming in discretionary activity hours using a line tracer and evaluated achievement level based on the outcome of learning by class period to assess the possibility of success. As a result, it could confirm that the programming learning using the line tracer was more excellent in creativity than the computer programming learning. In addition, it has been found that the programming learning method using the line tracer had a potential to be successful as a new creative tool that could replace the computer.

• Journal of Korean Home Economics Education Association
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• v.21 no.2
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• pp.139-158
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• 2009

The purposes of this study are to develop cyber home study program on consumer life for youth in middle school students and to compare the learning effect of this program with that of teacher's off-line lecture in class. The contents of the middle school Home Economics. Technology textbooks was analyzed. Based on this analysis 4 cyber home study lesson plans on youth's consumer life were developed. The topics of lesson plan were as 'youth and consumer behavior', 'utilizing consumer information'. 'effective consumer choice', 'resolving consumer problems'. The cyber home study were composed of 5 steps which were 'guiding' $\rightarrow$ 'learning activities' $\rightarrow$ 'evaluation' $\rightarrow$ 'further study' $\rightarrow$ 'summery'. The second grade middle school students as an experimental group participated in cyber home study through on-line class. The control group of students who had same condition with the experimental group were taught by home economics teacher using traditional instructional methods in off-line class. After the experiment, the changes in consumer's attitudes and knowledge of both groups were analyzed using Analysis of Covariance. The significant improvements of consumer's attitudes and knowledge were found in both the experimental and control groups of students. However, the consumer's attitudes and knowledge of the students who were taught by the teacher in off-line class improved more than those of the students who studied using cyber home study program in on-line class. Thus, the following conclusion is made that the cyber home study could be one of the useful learning methods to aid traditional off-line teaching in class.

• Progress in Superconductivity and Cryogenics
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• v.5 no.2
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• pp.20-29
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• 2003

As power systems grow more complex and power demands increase, the need of underground transmission system is increasing gradually. But it is very difficult and high in cost to construct new ducts and/or tunnels for power cables in metropolitan areas. HTS (High Temperature Superconducting) cable can carry very high current densities with strongly reduced conductor loss and allow high power transmission at reduced voltage. Therefore HTS cable can transfer more power to be moved in existing ducts, which means very large economical and environmental benefits. A development project for a 22kV class HTS cable is ongoing at a research centers, and the cable manufacturer in Korea. In this paper, we carried out investigation for application of 22kV class HTS cable in Korean utility networks. The results show that the HTS cable is applicable to replace IPB in pumping-up power plant, withdrawal line in distributed generation, withdrawal line in complex power plant, and conventional under ground cable. Finally, as the cost of HTS wire and refrigeration drops, the technical and economical potential of HTS cable is evaluated positively.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.510-512
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• 2000

This paper describes the voltage induced at neutral line and the proper location of lightning arrester in combined 22.9 kV class distribution line jointed overhead line and cable each other Modeling is established in ATP Draw to perform simulation. Simulated distribution line at this paper consists of distribution line 4.2km and underground distribution line 2km. Overvoltage and induced voltage are analyzed at several point of combined line. Analysis results was compared to select the best point to install arrester. Such analysis technology will be applied to obtaining capacity and location of arrester in the similar combined distribution line.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.8
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• pp.132-139
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• 2011

Technical requirements for medium voltage class circuit breaker were harmonized by IEC and IEEE, and IEC newly adopted the requirements for class S2 circuit-breaker for overhead-line with the ratings of high-frequency TRV(Transient Recovery Voltage), which IEEE already adopted. Under these circumstances, KERI(Korea Electrotechnology Research Institute) studied testing technologies and facilities, which enable to perform interrupting capacity tests for class S2 circuit-breaker. As results, KERI could carry out interrupting capacity tests for medium voltage class circuit breaker rated up to 3-phase 52[kV] 40[kA], which satisfies the IEC standard.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.343-356
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• 2022

As a part of round robin analysis to develop a finite element elastic-plastic seismic analysis procedure for nuclear safety class 1 components, a series of parametric analyses was carried out on the simulated pressurizer surge line system model to investigate sensitivity of the analysis results to finite element analysis variables. The analysis on the surge line system model considered dynamic effect due to the seismic load corresponding to PGA 0.6 g and elastic-plastic material behavior based on the Chaboche combined hardening model. From the parametric analysis results, it was found that strains such as accumulated equivalent plastic strain and equivalent plastic strain are more sensitive to the analysis variables than von Mises effect stress. The parametric analysis results also identified that finite element density and ovalization option in the elbow elements have more significant effect on the analysis results than the other variables.