• Journal of the Korean Vacuum Society
• /
• v.14 no.4
• /
• pp.245-251
• /
• 2005

A high performance dual rocking magnet sputtering gun has been developed. The rocking magnet sputtering gun introduces full-face erosion by rapidly rocking the magnet in the region where the high plasma density is maintained. The newly developed dual rocking magnet sputtering gun whose target utilization was 77 percent achieved high performance in quality in the view of target utilization and target life-time comparing to the existing magnetron sputtering gun. The PIC-MCC target erosion simulation has been performed simultaneously. Comparing experimental target erosion profiles with simulated target erosion profiles, the simulation could estimate the tendency of the target erosion profiles but could not estimate an exact target erosion profile. If the simulation were improved more precisely, the cost reduction for the development of the multiple rocking magnet sputtering gun would be expected.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.12 no.1
• /
• pp.636-643
• /
• 2020

This study developed a method for simulating greenhouse gas (GHG) emissions considering changes in conditions that may occur during the actual operation of small ships. Additionally, we analyzed and compared the results of the proposed method with that of existing emission simulations according to life-cycle assessment (LCA), thus verifying the proposed method's effectiveness. Through the results of the study, we confirmed that the proposed method improves the simulation by considering emissions due to ship operation, whereas existing methods focus on emissions caused by raw material production. Additionally, the proposed method could identify and quantify the relationship between changes in operating conditions and GHG emissions. We expect this GHG emissions simulation technique to help improve the environmental performance of ships in the future.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1993.10a
• /
• pp.1264-1272
• /
• 1993

The software for unmanned control of three row typed rice combine has been developed using fuzzy logic. Three fuzzy variables were used : operating status of combine, steering, and speed. Eleven fuzzy rules were constructed and the eleven linguistic variables were used for the fuzzy rules. Six sensors were use of to get input values and sensor input values were quantified into 11 levels. The fuzzy output was infered with fuzzy inferrence which uses the correlation product encoding , and it must have been defuzzified by the method of center of gravity to use it for the control. The result of performance test using graphic simulation showed that the intelligently unmanned control of a rice combine was possible using fuzzy logic control.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.11
• /
• pp.5819-5826
• /
• 2013

Purpose: The purpose of this study was to examine the effects of the simulation-based training for advanced cardiovascular life support on the knowledge and competence of nursing students. Method: The subjects were 22 nursing students, who ungraduated D university. Data were analyzed with SPSS/Win 18.0 program. Results: There was a significant improvement in knowledge and competence after receiving than before training. Conclusion: Simulation-based training for advanced cardiovascular life support is effective strategy for increasing the knowledge and competence of nursing students and will can provide basic data in development of standardized emergency nursing education programs. Further research is needed in the comparative analysis about various learning of advanced cardiac life support education and a longitudinal study of maintenance the knowledge and competence.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.16 no.4
• /
• pp.116-121
• /
• 2012

The construction of underground structures such as box culverts for electric power transmission is increasing more and more, and the life extension of these structures is very important. Carbonation-induced corrosion in concrete may often occur in a high carbon dioxide environment. In this study, the risk of carbonation of two concrete box culverts in an urban area was evaluated by measuring the carbonation rate and concrete cover depth. Then, the carbonation-free service life at the depth of the steel was calculated, based on in situ information, by the Monte Carlo simulation. The service life of box culvert due to carbonation was estimated over 250 years via Monte Carlo simulation.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.18 no.6
• /
• pp.30-40
• /
• 2014

The demand of underground structure such as box culvert for electric power transmission is increasing more and more, and the service life extension of these structures is very important. Recent observations in field and experimental evidences show that even steel in concrete can be corroded by carbonation reaction of cover concrete. Carbonation-induced corrosion in concrete may often occur in a high carbon dioxide environment. In this study, the risk of carbonation of box culverts in our nation was evaluated by measuring the carbonation rate and concrete cover depth in field. Then, the service life due to carbonation at the cover depth was calculated by in situ information and the Monte Carlo simulation in a probabilistic way. Additionally, the accelerated carbonation test for the cracked beam specimen was executed and the crack effect owing to the carbonation process on the service life of box culvert was numerically investigated via Monte Carlo simulation based on the experimental results.

• Tribology and Lubricants
• /
• v.20 no.5
• /
• pp.252-258
• /
• 2004

In this study, using high cycle fatigue (HCF) criteria, the simulation of rolling contact fatigue is conducted under elliptical contact. The HCF criteria fall into three categories: the critical plane approach, the stress invariant approach and the approach based on the mesoscopic scale. The accurate calculation of contact stresses and subsurface stresses is essential to the prediction of crack initiation life. Contact stresses are obtained by contact analysis of a semi-infinite solid based on the use of influence functions and the subsurface stress field is obtained using rectangular patch solutions. The simulation results show that the critical load is decreasing rapidly and the site of crack initiation also moves rapidly to the surface from the subsurface when the friction coefficient exceeds a specific value for all of three fatigue criteria.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.22 no.2
• /
• pp.321-329
• /
• 1998

To ensure the structural integrity of the autofrettaged thick-walled cylinder subjected to cyclic internal pressure loading, the fatigue crack propagation life of the cylinder was evaluated. Stress intensity factors of the external cracked cylinder due to internal pressure and autofrettage loadings were calculated using the finite element method. The fatigue crack propagation lives of the cylinder based on the fracture mechanics concepts were predicted and compared to the experimental fatigue lives evaluated from the C-shaped simulation specimens. There were good correlations between the predicted and experimental fatigue lives within a factor of 3 for the single and double grooved C-shaped simulation specimens. Predicted fatigue crack propagation lives of the double grooved cylinders were about 1.5-5 times longer than those of the single grooved cylinders depending on the levels of autofrettage.

• Journal of International Society for Simulation Surgery
• /
• v.3 no.2
• /
• pp.49-59
• /
• 2016

3D printing is also known as additive manufacturing technique in which has been used in various commercial fields such as engineering, art, education, and medicine. The applications such as fabrication of tissues and organs, implants, drug delivery, creation surgical models using 3D printer in medical field are expanding. Recently, 3D printing has been developing for produce biomimetic 3D structure using biomaterials containing living cells and that is commonly called "3D bio-printing". The 3D bio-printing technologies are usually classified four upon printing methods: Laser-assisted printing, Inkjet, extrusion, and stereolithograpy. In the bio-printing, bio-inks (combined hydrogels and living cells) are as important components as bio-printing technologies. The presence of various types of bioinks, however, in this review, we focused on the bio-inks which enables bioprinting efficacy using hydrogels with living cells.

• Structural Engineering and Mechanics
• /
• v.9 no.6
• /
• pp.557-568
• /
• 2000

As time-variant reliability approaches become increasingly used for service life prediction of the aging infrastructure, the demand for computer solution methods continues to increase. Effcient computer techniques have become well established for the reliability analysis of structural systems. Thus far, however, this is largely limited to time-invariant reliability problems. Therefore, the requirements for time-variant reliability prediction of deteriorating structural systems under time-variant loads have remained incomplete. This study presents a computer program for $\underline{REL}$iability of $\underline{T}$ime-Variant $\underline{SYS}$tems, RELTSYS. This program uses a combined technique of adaptive importance sampling, numerical integration, and fault tree analysis to compute time-variant reliabilities of individual components and systems. Time-invariant quantities are generated using Monte Carlo simulation, whereas time-variant quantities are evaluated using numerical integration. Load distribution and post-failure redistribution are considered using fault tree analysis. The strengths and limitations of RELTSYS are presented via a numerical example.