• Journal of Ocean Engineering and Technology
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• v.14 no.2
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• pp.1-6
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• 2000

Wave energy absorption by a flap equipped with a harbor in a water of finite depth is studied. The wave potential is calculated by a hybrid integral equation consisting of Green integral equations associated with Rankine and Kelvin Green functions. The absorbed wave energy is calculated by both the near-field and far-field methods. The present methods can be used for the design of a flap-harbor wave energy absorber since the numerical results by the two methods are in good agreement.

• Earthquakes and Structures
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• v.18 no.3
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• pp.391-405
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• 2020

The use of passive energy dissipation devices has been widely used in the construction industry to minimize the probability of damage occurred under intense ground motion. In this study, collapse margin ratio (CMR) and fragility curves are the main parameters in the assessment to characterize the collapse safety of the structures. The assessment is done on three types of RC frame structures, incorporating three types of dampers, viscoelastic, friction, and BRB dampers. The Incremental dynamic analyses (IDA) were performed by simulating an array of 20 strong ground motion (SGM) records considering both far-field and near-field seismic scenarios that were followed by fragility curves. With respect to far-field ground motion records, the CMR values of the selected frames indicate to be higher and reachable to safety margin more than those under near-field ground motion records that introduce a high devastating impact on the structures compared to far-field excitations. This implies that the near field impact affects the ground movements at the site by attenuation the direction and causing high-frequency filtration. Besides that, the results show that the viscoelastic damper gives better performance for the structures in terms of reducing the damages compared to the other energy dissipation devices during earthquakes.

• The Bulletin of The Korean Astronomical Society
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• v.32 no.1
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• pp.36.1-36.1
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• 2007

• Nuclear Engineering and Technology
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• v.53 no.2
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• pp.618-625
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• 2021

In this paper, the single-photon avalanche diodes (SPADs) featuring three different p-well implantation doses (∅_p-well) of 5.0 × 10¹², 4.0 × 10¹², and 3.0 × 10¹² atoms/cm² under the identical device layouts were fabricated and characterized to evaluate the effects of field enhanced mechanisms on primary dark pulses due to the maximum electric field. From the I-V curves, the breakdown voltages were found as 23.2 V, 40.5 V, and 63.1 V with decreasing ∅_p-well, respectively. By measuring DCRs as a function of temperature, we found a reduction of approximately 8% in the maximum electric field lead to a nearly 72% decrease in the DCR at V_ex = 5 V and T = 25 ℃. Also, the activation energy increased from 0.43 eV to 0.50 eV, as decreasing the maximum electric field. Finally, we discuss the importance of electric field engineering in reducing the field-enhanced mechanisms contributing to the DCR in SPADs and the benefits on the SPADs related to different types of radiation detection applications.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.363.2-363
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• 2001

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1867-1869
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• 1999

Pulse electric field induced electron emission from ferroelectrics has been studied with Pb$(Zr_xTi_{1-x})O_3$ ceramics with varying Zr/Ti ratio from 35/65 to 65/35, Electron emission was proved to be concentrated on the electrode edge by emission profile test and emission capture photographs. The 65/35 composition showed largest emission charge in lowest field and lowest emission threshold field. The emission characteristics are closely dependent on their ferroelectric properties in hysteresis curve. Electron emission charge increases with the polarization charge and emission threshold voltage is dependent on coercive field regardless of their composition. But dielectric constant has little relation with emission property. Electron emission charge increases exponentially with pulse electric field irrespective of composition. On the assumption that the surface potential is linear with the pulse electric field, electron emission can be regarded as a field emission at the electrode edge using Fowler-Nordheim plot of ln$(Q_e/E_{fe})$ to $1/E_{fe}$.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.37-37
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• 1999

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2015.10a
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• pp.171-172
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• 2015

• Asia Marketing Journal
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• v.16 no.1
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• pp.195-214
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• 2014

Many oil refinery companies have been proactively carried out marketing activities to survive in highly intensified service station industry. In 2012, SK Energy ranked number one in three customer satisfaction surveys (NCSI, KCSI, and KS-SQI). SK Energy's success is in its differentiated customer satisfaction business strategy. SK Energy has been implementing various marketing activities. As a part of the activities, it issued an affinity credit card with on spot discount privilege for the first time in the oil refinery industry. SK Energy also issued EnClean bonus card for OK Cashbag points that can be used for discounts at the service stations. On top of all, SK Energy generated point value-up with '3K Exclusive Privilege' program. In addition, team 'CS 119' was formed to noticeably improve the service. 'CS 119' visited each service station, diagnosed its CS service level then provided customized field training for improvement. Long-termimplementation of 'ACE Program', a field-base CS monitoring system, regularly checked customer satisfaction level. 'ACE Program' has significantly contributed improving SK Service Station's service quality and customer satisfaction. This case reviews customer satisfaction marketing activities SK Energy carried out. The focus is on distinctive factors that distinguish SK Energy's customer satisfaction marketing activities from competitors.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.521-522
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• 2004