• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.480-489
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• 2015

This study aimed to compare the education effect of easily accessible cardiopulmonary resuscitation (CPR) applications on smart-phones. The differences of performance and accuracy of CPR between animation CPR group and modified Pocket CPR group in Reserve Officers' Training Corps students of K university were evaluated by 2010 AHA guidelines. Data were collected from May 19, 2012 to May 20, 2012. There was no statistically significant difference between both of group in the performance and accuracy of CPR. However, the modified Pocket CPR group showed significant increase in the accuracy of chest compression depth (26.4%, p<.05), while the animation CPR group showed significant increase in the accuracy of chest compression location after the education (25.2%, p<.01). In conclusion, the methods using advantage and complementing disadvantage of animation CPR application and Pocket CPR application could help that people could easily access and perform to CPR.

• Tribology and Lubricants
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• v.37 no.4
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• pp.129-135
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• 2021

An air-bearing stage uses externally pressurized air as the lubricant between the stage and the rail. The supporting force generated by the supplied air makes the stage rise and move smoothly with extremely low friction. Mechanical contacts rarely happen, the bearing surfaces do not produce wear particles, and dust is not generated. It also has the advantage of having low energy loss and high precision. Because of its advantages, an air-bearing stage is used in several types of machines that require high precision. In this article, the effect of the pocket depth on the hammering phenomena of the air bearing is studied. An analysis program is developed to calculate the dynamic behavior of the stage by solving the Reynolds equation between the stage and the guideway and the equations of motion on the stage. The acceleration, constant movement, and deceleration are applied to the stage. The stage is modeled as a five-degree-of-freedom system. In the course of the dynamic behavior, the hammering phenomena occur under some special conditions. The deeper the pocket, the more unstable the behavior of the stage, and air hammering occurs when it exceeds a certain depth. In addition, the higher the supply pressure, the more unstable the behavior of the stage. However, hammering occurs even with a shallow pocket depth. Other conditions that affect the hammering phenomena are calculated and discussed.

• International Journal of Highway Engineering
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• v.10 no.2
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• pp.193-203
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• 2008

This study was conducted to investigate the feasibility of the expedite construction of new pavement systems using precast concrete slabs and to develop the design and construction guide based on the results of the experimental construction. Half scale concrete slabs were designed and fabricated and the optimal reinforcement design, linkages between the slabs in the longitudinal and transverse directions, and the grouting methods were investigated. The experimental construction was performed fast and easily by assembling two slabs in the longitudinal direction and the other two in the transverse direction. The slabs were leveled and the pockets and the space between the slab bottom and the underlying layer were grouted. From the experimental construction, details about the design and construction of the precast pavements were acquired. Finally, the design and construction guide for the newly constructed precast concrete pavement systems was developed.

• Journal of the Mineralogical Society of Korea
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• v.22 no.1
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• pp.1-11
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• 2009

Fine-grained peridotite xenoliths are rarely trapped in the basaltic rocks from the southeastern part of Jeju Island. Based on textural characteristics of the constituent phases showing uniform-sized, fine-grained tabular to mosaic grains with rare porphyroclastic relics, the studied samples can be defined as fine-grained, foliated porphyroclastic peridotites (FPP). Almost no significant difference among the FPPs in textures and major element compositions implies that the FPPs were derived from a structural domain, experiencing similar deformation events and deformation patterns. Moreover, the bimodal distribution with kink-banded porphyroclasts ($2{\sim}3mm$) and stain-free neoblasts ($200{\sim}300{\mu}m$), straight to gently curved grain boundaries with triple junctions, interstitial melt pockets, and microstructures for migrating grain boundary suggest that the studied samples went through dynamic recrystallization (${\pm}$ static recrystallization) in the presence of melt/fluid movement along foliation planes. No notable difference between the FPP and common protogranular xenoliths in major element compositions and geochemical evolution also implies that the FPP and protogranular xenoliths were from a similar horizon. Thus, the textural and geochemical characteristics of the FPPs reflects deformation events occurred at a localized and narrow zone within the lithospheric mantle beneath the Jeju Island. Although further detailed studies are necessary to define deformation events, the most possible process which could trigger deformation in the FPP in the rigid upper mantle was the ascending basaltic magma forming high-stress deformation zones. The suggested high-stress deformation zones in the lithosphere beneath the Jeju Island may be produced by paleo-faulting events related to the ascent of basalt magma before Jeju Island was formed.