• Journal of Digital Convergence
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• v.18 no.9
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• pp.441-451
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• 2020

The study was conducted with the aim of identifying the impact of competition anxiety on dance immersion and performance in high school students majoring in dance. As of 2020, online surveys were conducted on students majoring in dance at high schools in Seoul and the metropolitan area. A total of 222 people's data were processed by applying t-test, one-way variable analysis, correlation and multiple regression analysis through SPS 18.0 for Windows, resulting in the following conclusions. First, male students were more confident in their condition than female students, and students who recognized that their family's economic power was in the middle class were more aware. In addition, it was found that the group perceived that economic power was at the top of the list was higher than the median. Second, cognitive anxiety and self-confidence have been shown to have a static effect on immersion into dance. Third, cognitive anxiety and self-confidence have been shown to have a static effect on the achievement of uselessness. Fourth, immersion in dance appeared to be a powerful parameter related to competition anxiety and achievement of dance. To sum up the above conclusions, competition among high school students majoring in dance has been shown to increase their performance by immersing themselves in dance, but further studies of these psychological variables are expected to have side effects.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.1
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• pp.22-30
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• 2004

As an information-oriented society comes, many people use PC and depend on database that network server has. However, the online data can be missed when a blackout happens and also a power failure effects on standard of judgment on Power Quality. Thus, it is reason of a trend using interruption-free live-line work when a trouble happens to power system. However, the 83％ among the number of people who receive an electric shock experience when a laborer is doing interruption-free live-line works. In interruption-free method, the education and the training problem has been issued. However, we have a few instructors for that training. Furthermore, the trainees have short training period, just 4 weeks. In this paper, to develope the method that has no restriction of a time and place and reduce the wasteful materials, immersion type virtual reality(or environment) technology is used. The users of a 3D immersion type VR training system can interact with the system by doing same action in the real safe environment. Thus, it can be valuable to apply this training system to a dangerous work like as "Interruption-free live-line work exchanging COS(Cut-Out-Switch)". In this program, the user works with a instruction on the window and speaker and can't work other tasks until each part of the task completed. The workers using this system can use their hands and viewpoint movement as he is in a real environment but the trainee can't use all parts and senses of a real body with the current VR technology. Despite of this weak point, when we consider the trends of improvement in electrical devices and communication technology, we can say that 3D graphic VR application has a high potentiality.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.809-814
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• 2005

In this work, the thermal properties of epoxy coating system on the liner plate in the containment structure of nuclear power plants had been examined by irradiation and design basis accident (DBA) conditions. The effect of immersion in hot water on adhesion strength of the coating system had been also studied. The glass transition temperature ($T_g$) and thermal stability of ET-5290/carbon steel A 32 epoxy coating systems were measured by DSC and TGA analyses, respectively. Contact angle measurements were used to determine the effect of immersion on the surface energetics of epoxy coating system, with a viewpoint of surface free energy. Adhesion tests were also executed to evaluate the adhesion strength at interfaces between carbon steel plate and epoxy resins. As a result, it was found that the irradiation led to an improvement of internal crosslinked structure in cured epoxy systems, resulting in significantly increasing the thermal stability, as well as the $T_g$. Also, the immersion in hot water made a role in the post-curing of epoxy resins and increased the mechanical interlocking of the network system, resulting in increasing the adhesion strength of the epoxy coating system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.04a
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• pp.165-172
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• 1993

A non-linear mathematical model has been developed for the dynamic analysis of the reactor internals. The model includes a lumped mass and stiffness with non-linear members such as gap-spring. As hydrodynamic couplings have also been considered in the model, the effect of fluid/structure interaction between internals components due to their immersion in a confining fluid can be studied for the dynamic response analysis. The reactor internals responses for seismic and pipe break excitations have been calculated for the case of with-and without-hydrodynamic couplings.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2840-2851
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• 2022

Electric boilers (EBs) are the backup steam source for the auxiliary steam system of high-temperature gas-cooled reactor nuclear power plants. When the plant is in normal operations, the EB is always in hot standby status. However, the current hot standby operation strategy has problems of slow response, high power consumption, and long operation time. To solve these problems, this study focuses on the optimization of hot standby operations for the EB system. First, mathematical models of an electrode immersion EB and its accompanying deaerator were established. Then, a control simulation platform of the EB system was developed in MATLAB/Simulink implementing the established mathematical models and corresponding control systems. Finally, two optimization strategies for the EB hot standby operation were proposed, followed by dynamic simulations of the EB system transient from hot standby to normal operations. The results indicate that the proposed optimization strategies can significantly speed up the transient response of the EB system from hot standby to normal operations and reduce the power consumption in hot standby operations, improving the dynamic performance and economy of the system.

• International Commerce and Information Review
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• v.9 no.2
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• pp.257-283
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• 2007

As Global industrial structure is diversified, multinational corporations accomplished fast internationalization to introduction of new management policy by development of an IT technology. Enterprise' business environment is changing transcending border. To overcome raging waves of change accident and to be secured enterprise's future, the logistics is recognized the third profit source joining in curtailment of sale enlargement, production cost. To seek cost saving or reform in logistics class that is last area of pursuit of profits within ancient city life in the fast lane from these viewpoint, importance of study that integrates and manages international logistics bases supply neck walk is emphasized. Specially, to meet on in terms of competitive power security regarding curtailment of logistics cost is available through link between logistics bases, various consumer's request, merchandise and service logistics management that supply fixed quantity as is reliable in right place at good season was embossed by point game plan of business management, and SCM efficiency anger of mortification international logistics activity importance of study that see at that dominate competitive advantage point bring. This study analyzes interrelation and presents model for integration of international logistics bases supply network with supply network habit at factor and supply chain, and supply network activity in integration of supply chain process and production. Also, it establishes following method of study to achieve study purpose for actual proof analysis for integration sequence of international logistics bases supply network. Specially, immersion of network and supply network, very high interrelation appeared by thing which is with international logistics base supply network integration. The integration of international logistics base supply network means that the enterprises which give trust and sincerity deal with market environment change positively and can decide proceeding of various cooperative work. Also, it means the possibility by necessity of cooperative relation and interdependence to continuous immersion and normative immersion, for the maintain of long business relations.

• Journal of Mechanical Science and Technology
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• v.15 no.1
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• pp.98-107
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• 2001

Continuing efforts to achieve increased circuit performance in electronic package have resulted in higher power density at chip and module level. As a result, the thermal management of electronic package has been important in maintaining or improving the reliability of the component. An experimental investigation of thermosyphonic boiling in vertical tube and channel made by two parallel rectangular plates was carried out in this study for possible application of the direct immersion cooling. Fluorinert FC-72 as a working fluid was used in this experiment. Asymmetric heated channel of open periphery with gap size of 1, 2, 4 and 26mm and uniformly heated vertical tubes with diameter of 9, 15 and 20mm were boiled at saturated condition. The boiling curves from tested surfaces exhibited the boiling hysteresis. It was also found that the gap size is not a significant parameter for the thermosyphonic boiling heat transfer with this Fluorinert. Rather pool boiling characteristics appeared for larger gap size and tube diameter. The heat transfer coefficients measured were also compared with the calculation results by Chens correlation.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.8-14
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• 2008

For nondestructive inspection of electron beam (EB) welding part in automotive power transmission assembly, a pulse-echo ultrasonic testing apparatus in water immersion has been applied using the ultrasonic waves with a frequency of 10MHz. However various problems have appeared during the ultrasonic inspection, which led to some significant mistakes in automatic quality evaluation of the welding parts. Experimental study showed that the state of water couplant medium containing some amount of contaminants, rusts and anti-corrosion agents had considerable influences on the reduction of ultrasonic amplitudes during wave propagation. The amplitude reduction depending on the coupling medium state could bring about some mis-diagnoses for defects in the welding parts. The results proposed that for a reliable inspection of defects in welds the state of water medium should be kept in about 15 volume fractions (vol.%) of anti-corrosion agents and in minimized contaminants.

• Journal of the Korean institute of surface engineering
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• v.51 no.5
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• pp.291-296
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• 2018

In this study, we carried out an ultrasonic-chemical decontamination process with immersion type, reproduced in the laboratory. The corrosion damage characteristics, depending on kind of materials and ultrasonic process time, were investigated. Inconel 600, which showed lower corrosion potential and higher corrosion current density than that of STS 316, revealed severer corrosion damage and higher weight-loss rate than STS 316. Weight-loss rate of Inconel 600 increased with increasing ultrasonic process time. On the other hands, STS 316 presented a negligibly small corrosion damage, which was almost indistinguishable from visual observation. There was no effect of ultrasonic process time on the weight-loss rate of STS 316.

• Corrosion Science and Technology
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• v.16 no.1
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• pp.8-14
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• 2017

The corrosion behavior of a ferritic/martensitic steel T91 exposed to an aqueous solution containing chloride and sulfate ions is investigated depending on the stimulated all-volatile treatment (AVT) and under oxygenated treatment (OT) conditions. The corrosion of T91 steel under OT condition is severe, while the corrosion under AVT condition is not. The co-existence of chloride and sulfate ions has antagonistic effect on the corrosion of T91 steel in both AVT and OT conditions. Unlike to corrosion resistance in the aqueous solution, OT pretreatment provides T91 steel lower oxidation-resistance than VAT pretreatment. From scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis, the lower corrosion resistance in the aqueous solution by VAT conditions possibly is due to the formation of pits. In addition, the lower oxidation resistance of T91 steel pretreated by OT conditions is explained as follows: the cracks formed during the immersion under OT conditions accelerated peeling-off rate of the oxide film.