• Journal of the Korean institute of surface engineering
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• v.41 no.6
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• pp.255-263
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• 2008

Generally, deposition mechanism of diamond particle is mainly embedding effect in the kinetic spray process. Accordingly, in spite of high cost, helium gas was employed as process gas to get high diamond fraction in the composite coating. In this study, the deposition behavior of bronze/diamond by kinetic spray process was compared using different process gas (helium and nitrogen). Bare (mean size of $5{\mu}m$, $20{\mu}m$) and nickel coated diamond (mean size of $26{\mu}m$) were deposited on Al 6061-T6 substrate with fixed process temperature and pressure. For comparison with experimental results, plastic deformation behavior of nickel layer was simulated by finite element analysis (using ABAQUS/Explicit 6.7-2). The size, broken ratio, and fraction of diamond in the composite coating were analyzed through scanning electron microscopy and image analysis method. The uniform distribution and deposition efficiency of diamond particles in the coating layer could be achieved by tailoring the physical properties of the feedstock.

• Physical Therapy Korea
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• v.26 no.4
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• pp.20-28
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• 2019

Background: The wall squat exercise has been recommended for strengthening of the lower extremity muscles with maintaining lumbar lordosis. Although squat has been studied to be related to lower extremity extensor strength, the relationship between wall squat and lower extremity extensor strength unclear. Because squat and wall squat are biomechanically different, study on the relationship is needed. Objects: The purpose of this study was to determine the lower extremity extensor strength associated with wall squat performance. Methods: 74 healthy volunteers were recruited to participate in this study. The volunteers were measured hip and knee extensors strength and then performed wall squat exercise for maximum count. Results: We found significant relationships between wall squat performance and hip extensor strength normalized by body weight, knee extensor strength normalized by body weight and the composite value. In a regression analysis, hip extensor strength normalized by body weight explained 29% of the variation in wall squat performance in males and 35% in females. Conclusion: These results demonstrate that hip extensor strength normalized by body weight is critical to wall squat performance in both sexes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.559-560
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• 2012

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.3
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• pp.22-33
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• 1993

A theoretical analysis of predicting the detailed motion of a piston-crank mechanism within piston-guide clearance is presented, and the analysis is applied to the piston motion in a gasoline engine. A piston movement program is developed to calculate the piston attitude relative to the bore, the piston to bore impact velocity and kinetic energy loss and the net transverse force acting on the piston. This paper presents the formulation of a set of differential equations governing the transverse and rotational motion of a piston. These equations of motion were solved by well established Runge-Kutta method. As a result of this study, it is possible to predict the effects of piston geometry and piston pin offset on a piston motion and kinetic energy loss.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.111-120
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• 2008

The combustion reaction of polypropylene was investigated using a thermogravimetric technique under an air atmosphere condition at several heating rates from 10 to $50^{\circ}C/min$. To obtain information on the kinetic parameters, the dynamic thermogravimetric analysis curve and its derivative were analyzed by a variety of analytical methods such as Kissinger, Friedman, Freeman-Carroll, Chatterjee-Conrad, Ozawa and Coats-Redfern methods. The comparative works for the kinetic results obtained from various methods should be performed to determine the kinetic parameters, because there are tremendous differences in the calculated kinetic parameters depending upon the mathematical method taken in the analysis.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.2
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• pp.88-96
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• 2013

The objective of this research was to evaluate the suitability of sigmoidal and firstorder kinetic equations for simulating the methane production from solid wastes. The sigmoidal kinetic equations used were modified Gompertz and Logistic equations. Statistical criteria used to evaluate equation performance were analysis of goodness-of-fit (Residual sum of squares, Root mean squared error and Akaike's Information Criterion). Akaike's Information Criterion (AIC) was employed to compare goodness-of-fit of equations with same and different numbers of parameters. RSS and RMSE were decreased for first-order kinetic equation with lag-phase time, compared to the first-order kinetic equation without lag-phase time. However, first-order kinetic equations had relatively higher AIC than the sigmoidal kinetic equations. It seemed that the sigmoidal kinetic equations had better goodness-of-fit than the first-order kinetic equations in order to simulate the methane production.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.78-84
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• 2007

Quantitative analysis of dynamic brain PET data using a tracer kinetic modeling has played important roles in the investigation of functional and molecular basis of various brain diseases. Parametric imaging of the kinetic parameters (voxel-wise representation of the estimated parameters) has several advantages over the conventional approaches using region of interest (ROI). Therefore, several strategies have been suggested to generate the parametric images with a minimal bias and variability in the parameter estimation. In this paper, we will review the several approaches for parametric imaging with linearized methods which include graphical analysis and mulilinear regression analysis.

• Physical Therapy Korea
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• v.23 no.4
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• pp.55-62
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• 2016

Background: The functioning of the serratus anterior (SA) muscle is essential to normal scapulohumeral rhythm during forward flexion (FF) of the shoulder. Also, SA weakness and overuse of the upper trapezius (UT) is observed in patients with shoulder dysfunction and trapezius myalgia. We designed a combination exercise involving FF and scapular protraction with resistance (CFFSP) to activate the SA muscle and to deactivate the UT muscle. Objects: The purpose of this study was to determine whether or not CFFSP would be more effective in activating the SA muscle than FF alone and FF with scapular protraction (FFP). Methods: Nineteen subjects (12 men and 7 women) participated in this study and performed FF, FFP, and CFFSP at $120^{\circ}$. Surface electromyography was applied to the SA, UT, and pectoralis major (PM) muscles, as was one-way analysis of variance (ANOVA) with repeated measures. Statistical significance was set at .05. Bonferroni adjustment was used to counteract the problem of multiple comparisons, with a statistical level of significance of .017 (.05/3). Results: A statistically significant difference was found in relation to the three positions for the SA muscle (p<.001) and the SA/UT ratio (p=.005) using ANOVA. Significantly different results, depending on the position, were also demonstrated using the Bonferroni post-hoc test for the SA muscle ($FF=28.27{\pm}16.20$, $FFP=45.66{\pm}15.81$, and $CFFSP=62.4{\pm}27.21$) and for the SA/UT ratio ($FF=3.04{\pm}2.14$, $FFP=3.61{\pm}2.38$, and $CFFSP=5.95{\pm}3.01$). Significant differences between the three positions was not found regarding the average amplitude of SA/PM muscle ratio (SA/PM: p=.060). Conclusion: We recommend the use of CFFSP to strengthen the SA muscle at $120^{\circ}$.

• Journal of Korea Multimedia Society
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• v.24 no.8
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• pp.1184-1191
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• 2021

In a pop song, the creator's intention is communicated to the user through music and lyrics. Lyric meaning is as important as music, but in most cases lyrics are delivered to users in a static form without non-verbal cues. Providing lyrics in a static text format is inefficient in conveying the emotions of a music. Recently, lyrics video with kinetic typography are increasingly provided, but producing them requires expertise and a lot of time. Therefore, in this system, the emotions of the lyrics are found through the analysis of the text of the lyrics, and the deep learning model is trained with the data obtained by converting the melody into a Mel-spectrogram format to find the appropriate emotions for the music. It sets properties such as motion, font, and color using the emotions found in the music, and automatically creates a kinetic typography video. In this study, we tried to enhance the effect of conveying the meaning of music through this system.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.4
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• pp.475-483
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• 2014

PURPOSE: The purpose of the study was to determine the effects of close kinetic chain resistant exercise of lower extremity on the gait with stroke patients. METHODS: The subjects were 50 patients who were diagnosed with cerebrovascular accident. They were randomly assigned either to a close kinetic chain resistant exercise of lower extremity group (study group)(n=25) or open kinetic chain resistant exercise of lower extremity exercise group (control group)(n=25). Gait abilities were measured by using Timed Up & Go (TUG) test, Functional Gait Assessment (FGA) and spatio-temporal gait variable that were velocity, cadence, stride length, double limb support by 3 axises wireless accelerometer and sway angle of center of mass by same instrument. RESULTS: Study group and control group before and after the intervention there were significantly difference in TUG, FGA, spatio-temporal gait variables and sway angle of center of mass (p<.05). There were significantly different between study group and control group for all variables at post-exercise. CONCLUSION: When all is said and done it is expected to be used as a method for the treatment and prevention in the process of rehabilitation of patients with stroke. In its final analysis when applying resistant exercise of lower extremity to stroke patients' gait, close kinetic chain is more effective than open kinetic chain.