• Journal of Fisheries and Marine Sciences Education
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• v.20 no.3
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• pp.410-415
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• 2008

To evaluate the performance of nucleate boiling heat transfer between a plain and micro-fin surfaces, the experimental tests have been carried out under various conditions with fluorinert liquid FC-72, which is chemically and electrically stable. Two kinds of micro fins with the dimensions of $200{{\mu}m}{\times}20{{\mu}m}$ and $100{{\mu}m}{\times}10{{\mu}m}$ (width x height) were fabricated on the surface of a silicon chip. The experiments were performed on the liquid subcooling of 5, 10 and 20K under the atmospheric condition. The presented data showed a similar trend in the comparison with result of Rainey & You. Due to its expanded surface areas, the heat flux properties has been significantly enhanced on micro-fin surface comparing to the plain surface.

• Tribology and Lubricants
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• v.10 no.1
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• pp.69-77
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• 1994

Oil flow pass of hermetic scroll compressor with back pressure chamber was described. Dynamic analysis was preceded in order to obtain the loads on the lubricating contacts. The mobility method of dynamically loaded journal bearings was applied to the crank jornal bearing and lower main bearing, and they could be designed to operate under fluid film lubrication. From the consideration of their film thicknesses and oil flow rates, optimal bearing clearances or other bearing dimensions could be assessed. The major friction loss was calculated to be from the axial force between the two scrolls. Therefore, it was suggested that the designers should be careful to reduce the over-turning moment on the orbiting scroll.

• Structural Engineering and Mechanics
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• v.75 no.5
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• pp.607-620
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• 2020

A numerical study is carried out to assess the dynamic response and damage level of one- and two-way reinforced concrete (RC) panels subjected to explosive loads by using finite element LS-DYNA software. The precision of the numerical models is validated with the previous experimental test. The calibrated models are used to conduct a series of parametric studies to evaluate the effects of panel wall dimensions, concrete strength, and steel reinforcement ratio on the blast-resistant capacity of the panel under various magnitudes of blast load. The results are used to develop pressure-impulse (P-I) diagrams corresponding to the damage levels defined according to UFC-3-340-02 manual. Empirical equations are proposed to easily construct the P-I diagrams of RC panels that can be efficiently used to assess its safety level against blast loads.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.22-23
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• 2011

As device dimensions shrink, it is increasingly important to develop fabrication methods that can create sub-15 nm features of regular or arbitrary geometry in a rapid, parallel, and efficient process. This talk will discuss approaches based on self-assembling hybrid polymers containing Si. The thin films of those materials systems can generate well-ordered periodic arrays of dots or lines. For achieving, long-range ordering, it is helpful to use lithographically-defined templates, which are in general much larger than the length-scale of self-assembled nanostructures. For example, the self-assembly of polymer nanostructures can easily be templated using an array of nanoscale topographical elements that act as guiding templates or surrogates for one of two microdomains. The solvent-vapor-induced tunability of pattern dimension and morphology will be discussed as well. Those material systems can excellently serve for high-precision self-assembly that can provide good resolution, reliability, and controllability and be considered as an option for a future nanomanufacturing technology.

• Economic and Environmental Geology
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• v.24 no.1
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• pp.57-62
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• 1991

This study presents results of thermal stress calculations around the uplifted province within the continental lithosphere. A set of thermal stresses for the uplifted provinces are calculated using by assumption of two dimensions along the extension of the strike. The calculations utilize thermoelastic displacement potential function. Thermal stress distribution-faulting conditions inferred from this study are consistent with the suggested surface heat flow and place an important constraint on the thermal state of the uplifted provinces within the continental lithosphere.

• Transactions of the Society of Information Storage Systems
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• v.3 no.2
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• pp.81-85
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• 2007

Reliability of a hard disk drive depends on the head disk interface (HDI) characteristics. Particularly, the disk media and the head can be damaged due to contact between the two components during operation. The contact may occur due to particles being introduced into the disk/slider interface or due to direct contact between the slider and the disk. Such contacts may be induced by external vibration or abnormal operation of the HDI. In this work the characteristics of scratches generated on the disk surface were investigated. The scratches were generated by impacting the hard disk. The type of scratches was analyzed with respect to their shape and dimensions.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.4
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• pp.510-519
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• 2015

Concerning the issue of high-dimensions, hybrid uncertainties of randomness and intervals including implicit and highly nonlinear limit state function, reliability analysis based on the hybrid uncertainty reliability mode combining with back propagation neural network (HU-BP neural network) is proposed in this paper. Random variables and interval variables are as input layer of the neural network, after the training and approximation of the neural network, the response variables are obtained through the output layer. Reliability index is calculated by solving the optimization model of the most probable point (MPP) searching in the limit state band. Two numerical cases are used to demonstrate the method proposed in this paper, and finally the method is employed to solving an engineering problem of the aerospace friction plate. For this high nonlinear, small failure probability problem with interval variables, this method could achieve a good analysis result.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2008.10b
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• pp.301-306
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• 2008

The World Wide Web (WWW) has continued to grow at very rapid speed in both the sheer volume of traffic and size and the complexity of Web sites. Web Analytics Industry also has been growing rapidly. Web Analytics is to analyze web log files to discover accessing patterns of web pages. In this paper, we identify factors which can affect the continuous usage intention of a firm using services in web analytics services and empirically validate the relationships between the identified factors. For this purpose, we analyze 174 Korea firms. The analysis results show that the satisfaction is significantly associated with service quality and switching cost and the service usage period is not significantly associated with continuous service usage intention. We measure the service quality using SERVQUAL. It turn out that two dimensions of SERVQUAL, reliability and empathy are significantly associated with satisfaction, but another dimension of SERVQUAL, responsibility, is not. Finally, satisfaction is significantly associated with continuous service usage intention.

• KSBB Journal
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• v.9 no.5
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• pp.512-517
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• 1994

The morphology of fungal growth, which is an important variable for separability and rheological property of fermented medium, was quantified with fractal geometry. Fractal dimensions were determined for submerged growth of two industrially important fungi, Aspergillus niger and Aspergillus oryzae. The tendency of pellet formation was related to the fractal dimension of fungi.

• Journal of the Korean Home Economics Association
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• v.36 no.12
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• pp.129-143
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• 1998

The purpose of this study was to develop a Korean Coping Strategy Scale and to examine coping characteristics of Korean housewives form urban low-income families using this Scale. Two hundred and forty mothers were either interviewed or filled out this Coping Strategy Scale and Demograpic Information Questionnaire. The Coping Strategy Scale consisted of 14 items under 4 dimensions of problem-solving, support-seeking, emotion-regulation/explosion, and abandonment. Item analysis and construct validation were found acceptable. The alpha coefficient of the Scale was 73. The results showed that the mothers used problem-solving most as a coping strategy, followed by supportseeking and emotion-regulation/explosion. Abandonment coping strategy was used least frequently. The demographic variables of mother's and their husbands' age, duration of marriage, income and expenditure per moth were significantly related to mothers' coping strategies.