• The Journal of Korean Academy of Prosthodontics
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• v.56 no.4
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• pp.278-286
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• 2018

Purpose: The purpose of this study was to evaluate the effect of healing abutment height and measurement angle on implant stability when using Periotest and AnyCheck. Materials and methods: 60 implants were placed into artificial bone blocks. After implant insertion, 2, 3, 4 and 5 mm healing abutments were installed on 15 specimens, respectively. Insertion torque value, implant stability test, Periotest value were measured. Insertion torque value was controlled between 45 - 55 Ncm. AnyCheck was used for measuring implant stability test and Periotest M was used for measuring Periotest value. Implant stability test and Periotest value were measured at the angles of 0 and 30 degrees to the horizontal plane. Measured values were analyzed statistically. Results: Insertion torque value had no significant difference among groups. When healing abutment height was higher, implant stability test and Periotest value showed lower stability. Also when measurement angle was decreased, implant stability test and Periotest value showed lower stability. Conclusion: When measuring stability of implants with percussion type devices, measured values should be evaluated considering height of healing abutments and measurement angle.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.86-92
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• 2009

In the safety check of gravity dams at earthquake, there have been two types of analysis conducted simultaneously; one is stability analysis and the other stress analysis. But those are essentially the same calculation other than the former considers the dams rigid, while the latter considers the dams' dynamic characteristics which results in the amplification of response acceleration on the upper part of dam body. In this paper, the identity of those two methods is verified by example calculation in terms of stability check of gravity dam. It can be concluded that if stress analysis were performed, stability check of gravity dam could be accomplished with the results from stress analysis, removing unnecessary present dual calculation practice.

• Journal of KSNVE
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• v.4 no.2
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• pp.221-230
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• 1994

This paper deals with the dynamic stability and the nonlinear behavior of a check valve system. The nonlinear equations of motion of fluid-valve interation model are derived, which are composed of the unsteady Bernoulli's equation included the jet flow mechanism and equation of motion of a check valve formulated by one degree of freedom. Also, the derived equations of motion are nondimensionalized. According to the change of the nondimensional parameters, the stabilities of the system are analyzed, and the nonlinear interaction responses of the check valve and the passing flow rate are obtained. As the results, the stability charts are constructed for the variation of nondimensional parameters. It is shown that self-excited vibrations exist in a check valve system. And also the Hopf bifurcation and the periodic doubling are found. The presented theoretical model of a check valve system can be utilized to the design and operation of a piping system with the check valve.

• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.594-600
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• 2006

In this study, transient and quasi-static analysis were done for the evaluation of structural integrity of the platform screen door due to train wind pressure. Fluent 6.0 was used to calculate the train wind pressure, and Ansys 10.0 was used to evaluate the structural stability of platform screen door due to train wind pressure. Transient analysis was used to check the design requirements of platform screen door, and quasi-static analysis was introduced to save the calculating time and check quickly structural performances when compared to those of transient analysis. The results show that structural stability of the platform screen door under train wind pressure is proven and quasi-static analysis can quickly check the structural integrity of platform screen door.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.901-906
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• 1989

A robust stability problem for time delay systems is discussed by using a property of Lyapunov type operator equation. We propose a method to check the robust stability against the parameter perturbations occurring in both lumped parameter part and distributed delay element.

• The KSFM Journal of Fluid Machinery
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• v.10 no.1 s.40
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• pp.41-48
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• 2007

The effect of the upstream flow conditions on the disc stability of the swing check valves was investigated at various upstream flow disturbance sources and distances from the tested check valves. The experimental loop was designed and installed to measure the disc positions, disc back stop load, and differential pressure at flow velocities lot 3 inch and 6 inch swing check valves. The selected disturbance sources are elbow and globe valve. The effect of the disc fluctuation is different depending on the type of disturbance and the distance between the disturbance and the check valve. Disturbances generated by elbow and globe valve located upstream from check valve create greater and more violent disc motion than uniform flow.

• Honam Mathematical Journal
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• v.32 no.1
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• pp.167-176
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• 2010

Let (B, $\check{g}$) and (N, $\hat{g}$) be Einstein manifolds. Then, we get a complete (necessary and sufficient) condition for the warped product manifold $B\;{\times}_f\;N\;:=\;(B\;{\times}\;N,\;\check{g}\;+\;f{\hat{g}}$) to be Einstein, and obtain a complete condition for the Einstein warped product manifold $B\;{\times}_f\;N$ to be weakly stable. Moreover, we get a complete condition for the map i : ($B,\;\check{g})\;{\times}\;(N,\;\hat{g})\;{\rightarrow}\;B\;{\times}_f\;N$, which is the identity map as a map, to be harmonic. Under the assumption that i is harmonic, we obtain a complete condition for $B\;{\times}_f\;N$ to be Einstein.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.277-280
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• 2013

This study was carried out to compare the productivity and to evaluate the stability for the introduced sweet corn hybrids; Sunnychocolat, 7168Y and Gammiok as a check hybrids. The used materials were planted at Anseong and Daejeon by randomized block design with 3 replications on 21 April, 2013. In productivity of the used hybrid corns, plant and ear height showed comparatively stable as a 183.5 cm to 226.5 cm and 45.8 cm to 80.9 cm, respectively. In yield per 10a, number of ears was higher in Sunnychocolat than check, while Gammiok was very poor in kernel setting length and marketability. Beside, stability of the used hybrids also showed highly in the introduced hybrids than check in the ratio of ear to plant height, tolerance to environmental stress and low lodging. As results above, we thought that these introduced hybrids will be well adapted in domestic cultivation and growth habit as like other hybrid corns.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.309-314
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• 2004

The experimental loop was designed and installed to measure the disc positions, disc back stop load and differential pressure with flow velocity for 3 inch and 6 inch swing check valves. The tests were performed at various conditions of upstream flow disturbance source and distance from the tested check valves to investigate the effect of the upstream flow conditions on the disc stability of the swing check valves. The selected disturbance sources were elbow, globe valve, and orifice. The experimental results are presented herein.

• Transactions of Materials Processing
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• v.6 no.5
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• pp.416-424
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• 1997

In the present study, a contact search and check algorithm for general tool surface described by triangular FE patch is proposed. To improve numerical stability, SEAM element using the linear Coons interpolation has been used. To check the proposed algorithm, both clover cup and L-shape cup deep drawing processes are calculated. The computed results shows that the proposed contact algorithm can be successfully applied for sheet metal forming processes with general shaped tools.