• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4159-4169
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• 2022

Hydrogen mitigation using Passive Autocatalytic Recombiners (PARs) has been widely accepted methodology inside reactor containment of accident struck Nuclear Power Plants. They reduce hydrogen concentration inside reactor containment by recombining it with oxygen from containment air on catalyst surfaces at ambient temperatures. Exothermic heat of reaction drives the product steam upwards, establishing natural convection around PAR, thus invoking homogenisation inside containment. CFD models resolving individual catalyst plate channels of PAR provide good insight about temperature and hydrogen recombination. But very thin catalyst plates compared to large dimensions of the enclosures involved result in intensive calculations. Hence, empirical correlations specific to PARs being modelled are often used in integral containment studies. In this work, an experimentally validated CFD model of PAR has been employed for developing an empirical correlation for Indian PAR. For this purpose, detailed parametric study involving different gas mixture variables at PAR inlet has been performed. For each case, respective values of gas mixture variables at recombiner outlet have been tabulated. The obtained data matrix has then been processed using regression analysis to obtain a set of correlations between inlet and outlet variables. The empirical correlation thus developed, can be easily plugged into commercially available CFD software.

• The Journal of Information Systems
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• v.32 no.4
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• pp.69-94
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• 2023

Purpose Social networking service (SNS) platforms employ distinct networking strategies to meet the varying needs of their users, resulting in divergent sets of technological functionalities offered by each platform. Consequently, unique features on various SNSs give rise to distinct social issues. Moreover, the available technical coping mechanisms for users vary significantly across platforms. Design/methodology/approach Therefore, this study analyzes the factors affecting technical coping intention based on technical functions of SNSs for users exposed to cybercrime, such as sexual harassment. We divide coping intention into active and passive coping intention. Furthermore, this research focuses on trust as an antecedent of coping intention and verifies how human and system-like trust affects two coping intentions in different directions. Findings Findings reveal that system-like trust significantly affects both active and passive coping intention as a belief in whether the technology will work properly. However, in the case of human-like trust, trust in the platform provider was found to negatively affect passive coping, which is considered unsocialized behavior on SNS platforms. Therefore, both human-like and system-like trust for the platform must be appropriately applied to cope with the problem while activating the platform.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.17-22
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• 2005

This paper presents a improvement equivalent circuit model for Miniaturized LTCC bandpass filter with two transmission zeros using feed-back capacitor. The bandpass filter equivalent circuit is evaluated by parallel network analysis. Besides, the filter is modeled by proposed passive element modeling algorithm in previous work. Compared to the equivalent circuit of established paper that is configured by excepted capacitance between ground plate and signal plate, this model can include that. The result, the LTCC bandpass filter reduce layers and the size is more smaller.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.520-524
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• 2004

In this work, a novel spherical 3-dof parallel mechanism is proposed and analyzed. The mechanism consists of three RRPS serial subchains and an additional passive 3-dof type serial subchain. Three RRPS serial subchains alone may form a structure of 6-DOF Stewart Platform mechanism. However, in the proposed mechanism, an additional passive serial subchain acts as constraints to restrict the output motion of the mechanism within 3-DOF spherical space. The closed form solutions of position analysis of the proposed mechanism and its first-order kinematic model are derived. Then its workspace size and kinematic characteristics are examined via kinematic isotropic index.

• Journal of KSNVE
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• v.11 no.2
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• pp.241-248
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• 2001

The present paper describes experimental and computational work to augment the magnitude of the impulsive wave. An experiment was performed using a simple shock tube with an open end and numerical calculations were carried out to solve the unsteady, axisymmetric, inviscid, compressible governing equations. The control strategy applied was to alter the exit geometry of a straight tube to a sudden enlargement tube and a flare tube. The effects of the configurations of the tube exit on the magnitude of the impulsive wave were investigated over the range of the weak shock Mach number from 1.01 to 1.10. The results obtained were compared to those of the straight tube tests. The numerical result predicted the magnitude of the experimented impulsive waves with a good accuracy. The present passive control technique enabled the magnitude of the impulsive wave to augment by about 23 percent, compared to that of the straight tube of no control.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.678-681
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• 2002

In this paper, Characterization for several 3-D embedded passive elements with different structures was performed. The equivalent circuit optimization for embedded inductor was performed by HSPICE simulation software. After extracting each parameter values, the difference of parameter from each structure was examined. From this work, effective characterization of passive devices with similar structure will be possible.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.669-672
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• 2003

With the advances on wireless internet technology, many research on minimization of wireless LAN is on the progress. To apply passive components in MCM, characteristic analysis of passive components is essential. In this paper, three square spiral inductors were modeled by HSPICE using PEEC (Partial Element Equivalent Circuit) method. Afterwards, Monte-Carlo analysis was performed to evaluate the optimized parameters. This work will give an idea on PEEC modeling of spiral inductor, and enable researchers with predictive data before large scale manufacturing.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.543-544
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• 2008

Nowadays, the research on the system integration using various technologies, like MCM-C, MCM-L and MCM-D. Especially, MCM-D technology is suitable for mmwave application due to its high resolution of patterning and thermal property similar to that of semiconductor devices. In this work, integrated passive devices like inductor, capacitor and resistor are evaluated on the GaAs substrate and their characteristics are examined. And finally, the Wilkinson power divider using lumped IPD are evaluated on GaAs substrate and it shows low insertion loss below 0.5 dB and the isolation over 15 dB.

• Journal of the Optical Society of Korea
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• v.3 no.2
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• pp.74-79
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• 1999

We present a simple design rule for a passive temperature-compensating optical package. We also present experimentally that a package fabricated by using the design rule compensates the temperature dependence of the resonant wavelength of an optical long period fiber grating by varying the strain inside the fiber, The package fabricated in this work consists of two pieced of brass tube, 10 mm long, and a piece of nylon rod, 45.4 mm long. It is shown that the package can compensate the temperature-induce wavelength shifts of the long period grating to a range of 6.8 pm/$^{\circ}C$, compared with 0..48 nm/$^{\circ}C$ for an uncompensated grating. The reduced strength of the fiber caused by exposure to ultraviolet limits the performance of the package to the range operating temperature form -3 $^{\circ}C$ to 7$0^{\circ}C$.

• Journal of the Korea Society of Computer and Information
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• v.23 no.5
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• pp.47-53
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• 2018

This study is aimed to determine types of job values which is searched by 242 university student in Gwangju, to study characteristics of each type, and to analyze key competency of each type. The data were analyed with PASW 18.0 using frequency analysis, k-mean cluster analysis, crosstabs and one-way ANOVA. According to findings, first of all, university student types of job values are divided into 4 groups; a type of intrinsic job values(27.7%), a type of active job value(32.2%), a type of external job value(12.4%), a type of passive job value(27.7%). Secondly, the type of job values showed statistically significant difference only in the monthly allowance of socio-economic variables. Thirdly, the type of job values showed statistically significant difference 'communication', 'mathematics', 'problem solving', 'self development', 'resource management', 'interpersonal skills', 'technical ability', 'understanding organizations' and 'work ethics'.