• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1775-1780
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• 2003

A hybrid finite element analysis was used to analyze the influence of ring gear rim thickness and spline number on the static properties of an epicyclic gear system with manufacturing errors. Both of these parameters affected the bearing force and critical stress. The effect of changes in the rim thickness on the load sharing between the gears depended on the type of manufacturing error. Ring flexibility improved the load sharing between planetary gears only in systems with planet tooth thickness or planet tangential errors; for other types of error, ring flexibility worsened the load sharing. To improve load sharing, rim thickness and spline number should be controlled within a specific range. The effect of the ring gear boundary condition was more apparent in a system with errors than in a normal system.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.103-113
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• 1999

Point contact film thickness in elastohydrodynamic lubrication (EHL) is analyzed by the image processing method for the monochromatic incident light. Interference between the reflected lights both on Cr coating of glass disk and on super finished ball makes circular fringes, which are regarded as film thickness together with numbering of fringe order. In this study, we developed technology to measure the film thickness by analyzing dark and bright intensity waves which results from monochrome green light. Two typical fringe patterns only with intensity values 3re examined for the measurement of point contact EHL film thickness. We expect that this technology will give valuable clue to improve color image processing analysis for high resolution of EHL film thickness with white incident light.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.2
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• pp.253-261
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• 2013

PURPOSE: The Purpose of this study was to investigate the changes in the thickness of Sternocleidomastoid muscle(SCM) and deep cervical flexor muscle(DCF) through CranioCervical Flexion Exercise(CCFEx) Using Sling. METHODS: Subjects were randomly allocated two group: control group (n=21) without neck pain, experimental group (n=17) with pain. Muscle thickness was measured using CranioCervical Flexion Test(CCFT) and ultrasonography before or after intervention. RESULTS: In experimental group, compared with muscle thickness of exercise before, SCM thickness rate of change was slightly decreased according to pressure increased after exercise(p<.05). CONCLUSION: The results of this study showed that CCFEx using sling is effective for SCM and DCF of choric neck pain patients.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.23 no.4
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• pp.1-5
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• 2015

In this work, a study was conducted to investigate the effect of diaphragm thickness on the regression rate of the hybrid rocket motor. To observe the flow pattern and the recirculation zone, visualizations of combustion chambers with different diaphragm thickness (5mm, 10mm) were performed. It was found that the case with 5 mm thickness had a larger recirculation zone and therefore, had a higher regression rate than the case with 10mm thickness due to the increased residence time and heat transfer toward the fuel surface. Finally, it was concluded that the thickness of diaphragm can be a critical parameter for the enhancement of the regression rate.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.8
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• pp.559-567
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• 2015

The paper deals with an ultrasonic transducer invented for measuring both flow velocity and pipe thickness. The structure of the transducer is based on the conventional transducers for measuring flow velocity by obliquely transmitting ultrasonic waves to the flow direction. The transducer additionally generates ultrasonic waves transmitting vertically to a pipe for measuring pipe thickness. By measuring flow velocity with the invented transducer and a conventional oblique-incidence transducer and comparing their results, the accuracy of the flow velocity measurement of the invented one was evaluated. By measuring specimen thickness with the invented transducer and a conventional normal-incidence transducer and comparing their results, the accuracy of the thickness measurement of the invented one was evaluated.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.329-329
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• 2011

We measured thin films thickness sputtered from Cu target in the magnetron sputter system. Thin films thickness is thin as integration power in target is large. Cu thin films thickness in 100 kWh integration watt was decreased by 20% when that of beginning was compared. But the shape of thin films thickness distribution was same. For the calculation of thin films thickness distribution in the 100 kWh, the angular distribution data sputtered of Cu particles is necessary when Ar ions enter to inclined erosion surface of Cu target. We used the relation results of sputter yield and main angular distribution of sputtering particles emitted from Cu target published by G. Betz.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.399-403
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• 2005

Slope angle, ground water table and thickness of soils are the key factors affecting landslide stability. However examining the factors such as thickness of soils; geological structure, slope angle, and height, in order to use the global landslide susceptibility forecasting analysis is very expensive and time consuming effort. So most researchers prefer to use the simplest methods such as the C strata and the USGS methods. In this research thickness of soils was calculated using these two methods and stability analysis was performed with the thickness of soils calculated by the two methods at the SINMAP based on ArcView 3.2. The two safety factor maps were compared with the past landslide records. The thickness of soils calculated by USGS method showed more unstable safety factors.

• Steel and Composite Structures
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• v.19 no.3
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• pp.679-695
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• 2015

A numerical solution using finite difference method to evaluate the thermal buckling of simply supported FGM plate with variable thickness is presented in this research. First, the governing differential equation of thermal stability under uniform temperature through the plate thickness is derived. Then, the governing equation has been solved using finite difference method. After validating the presented numerical method with the analytical solution, the finite difference formulation has been extended in order to include variable thickness. The accuracy of the finite difference method for variable thickness plate has been also compared with the literature where a good agreement has been found. Furthermore, a parametric study has been conducted to analyze the effect of material and geometric parameters on the thermal buckling resistance of the FGM plates. It was found that the thickness variation affects isotropic plates a bit more than FGM plates.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.252-255
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• 2009

The roll gap set-up in the finishing mill is one of the most important technologies in the hot plate rolling process. As the target thickness can be obtained by the correct set-up of the roll gap, improving the roll gap set-up technology is very critical for plate thickness accuracy. The main cause of thickness variation in hot plate mills is the non-uniform temperature distribution along the length of the slab. The objective of this study is to adjust the roll gap set-up for the thickness accuracy of plate in hot rolling process considering top-end temperature drop. Therefore this study has concentrated on determining the correct amounts of roll gap to compensate thickness variation due to top-end temperature drop. The off-line simulation of compensated roil gap significantly decreases top-end thickness variation.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.116-119
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• 2007

To get abundant germplasm for developing new waxy corn varieties, pericarp thickness was measured and other factors were evaluated with a total of 142 Korean local waxy corn lines collected from various parts of Busan City and Gyungnam Province. The average pericarp thickness of Korean local waxy corn lines collected was $40.61{\mu}m$ and the rate of thin pericarp under $50{\mu}m$ was 70.4%. The pericarp thickness compared by the regions collected showed non significant difference, but which compared by the ear row number per ear showed significant difference $(MS=597.52^*)$. Correlation between pericarp thickness and row numbers per ear was low (-0.93).