• Journal of the Korean Society for Railway
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• v.6 no.3
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• pp.186-193
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• 2003

The object of this study is to ensure the stability of bulk cement cars conducting vibration performance test, dynamic characteristic analysis and static load test of bogie frame. In case of static load test, bogie static load test facility was used. In case of dynamic characteristic analysis, Vampire Software was used. In case of vibration performance test, real bulk cement cars were used in kyeung-bu line. In the results of static load test of bogie frame for bulk cement car, all structures satisfied allowable stress criteria of materials. The vibration performance test and dynamic characteristic analysis results satisfied allowable standards.

• PNF and Movement
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• v.9 no.4
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• pp.13-21
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• 2011

Purpose : The purpose of this study was to analyze the effect of closed kinematic chain exercise and proprioceptive neuromuscular facilitation exercise on the static dynamic balance performance of hemiplegic patients in order to suggest them therapeutic intervention methods. Methods : The subjects of this study were 18 hemiplegic patients grouped into 2 subgroups according to the exercise program. one group of closed kinematic chain exercise carried out sit to stand, Hooklying with pelvic lift(bridging) and stair-up & down by a hemiplegic leg. The other group of proprioceptive neuromuscular facilitation exercise carried out leg flexion-extension pattern in supine position, leg flexion pattern in standing and stabilizing reversal exercise in stating position. Each exercise was carried out over 3 sets of 10reps. Results : The results of this study were summarized as follows: 1. For both groups, there were statistically significant changes in the static balance (FICSIT-4) performance after exercise program (p<.05). 2. For both groups, there were statistically significant changes in the dynamic balance (FSST, TUG, FRT) performance after exercise program (p<.05). 3. In the comparison between both groups, there was no statistically significant difference in the static dynamic balance performance (FICSIT-4, FSST, TUGT, ER) after exercise program. Conclusion : As the results of the study shows closed kinematic chain exercise and proprioceptive neuromuscular facilitation exercise affect the improvement of hemiplegic patients'' static dynamic balance performance, it is supposed that these exercises could be therapeutic exercise program in clinical situations.

• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.2009-2020
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• 2004

A parametric study of the factors controlling static and dynamic denting, as well as local stiffness, has been made on simplified panels of different sizes, curvatures, thicknesses and strengths. Analyses have been performed using the finite element method to predict dent resistance and panel stiffness. A parametric approach is used with finite element models of simplified panels. Two sizes of panels with square plan dimensions and a wide range of curvatures are analysed for several combinations of material thickness and strength, all representative of auto-motive closure panels. Analysis was performed using the implicit finite element code, LS-NIKE, and the explicit dynamic code, LS-DYNA for the static and dynamic cases, respectively. Panel dent resistance and stiffness behaviour are shown to be complex phenomena and strongly interrelated. Factors favouring improved dent resistance include increased yield strength and panel thickness. Panel stiffness also increases with thickness and with higher curvatures but decreases with size and very low curvatures. Conditions for best dynamic and static dent performance are shown to be inherently in conflict ; that is, panels with low stiffness tend to perform well under impact loading but demonstrate inferior static dent performance. Stiffer panels are prone to larger dynamic dents due to higher contact forces but exhibit good static performance through increased resistance to oil canning.

• Journal of the Korean Wood Science and Technology
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• v.49 no.5
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• pp.504-513
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• 2021

In this study, cross-laminated wood panels were manufactured with four softwoods and three hardwoods with the goal of efficiently predicting the static strength performance using dynamic modulus of elasticity (MOE) and simultaneously revealing the dynamic performance of cross-laminated wood panels. The effect of the density of the species on the dynamic MOE of the laminated wood panels was investigated. Moreover, the static bending strength performance was predicted nondestructively through the correlation regression between the dynamic MOE and static bending strength performance. For the dynamic MOE, the parallel- and cross-laminated wood panels composed of oriental oak showed the highest value, whereas the laminated wood panels composed of Japanese cedar showed the lowest value. In all types of parallel- and cross-laminated wood panels, the density dependence was confirmed, and the extent of the density dependence was found to be greater in the P_⊥ and C_⊥ types with perpendicular-direction laminae in the faces than in the P_∥ and C_∥ types with longitudinal-direction laminae in the faces. Our findings confirmed that a high correlation exists at a significance level of 1% between the dynamic modulus and static bending modulus or bending strength in all types of laminated wood panels, and that the static bending strength performance can be predicted through the dynamic MOE.

• Tribology and Lubricants
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• v.20 no.5
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• pp.245-251
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• 2004

This paper presents the effects of the bump foil stiffness on the static and dynamic performance of the foil journal bearings. Reynolds equation is used for the static and dynamic performance analyses. To consider the deflection of top foil the top foil is modeled as a elastic beam and the bump foil is modeled as a spring. So in the static performance analysis the load capacity is compared to the various bump foil stiffness and in the dynamic performance analysis the trajectory of journal center is compared to the various bump foil stiffness.

• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.1-19
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• 2002

The purpose of this study is to identify influence that eye movement have an effect on postural control and balance performance by plegia side of the impaired patients of central nervous system. Subjects are patients with the impairment of central nervous system and experimental and control groups are forty people and thirty people seperatively, Total subjects were selected to seventy persons, but twelve persons of experimental group quit during the experimental periods and eight persons of control group did not measure after exercise. Therefore, twenty eight persons of experimental group and twenty two persons of control group were selected in this study and experimental group peformed eye movement for eight weeks according to the exercise program of this study. The measurement of dependent variable is right static balance, left static balance, bilateral static balance, and bilateral dynamic balance before exercise and after eighth week of exercise, examiner again measured and analyzed the results. The results were as follows: 1. As the result of comparing balance performance ability after test of the experimental and control group with right hemiplegia and control group, all of static balance performance ability of right side (p < 0.01), static balance performance ability of left side (p < 0.01), static balance performance ability of bilateral side(p < 0.01), dynamic balance performance ability of bilateral side(p < 0.05) of experimental group were statistically greater improved than those of the control group. 2. As the result of comparing balance performance ability after test of the experimental and control group with left hemiplegia and control group, all of static balance performance ability of right side (p < 0.01), static balance performance ability of left side (p < 0.01), static balance performance ability of bilateral side(p < 0.05), dynamic balance performance ability of bilateral side(p < 0.05) of experimental group were statistically greater improved than those of the control group.

• The Journal of Korean Physical Therapy
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• v.29 no.3
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• pp.142-144
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• 2017

Purpose: Few studies have addressed the effect of diurnal circadian rhythms on postural stability, and thus the aim of the present study was to examine circadian effects on static and dynamic postural stability in young adults. Methods: Twenty-four subjects (9 men, 11 women: age=$22.20{\pm}1.77$, height=$167.20{\pm}10.47$, weight=$59.85{\pm}10.66$) from a university community volunteered for this study. Static and dynamic balance testing, which recorded using a Good Balance system (Good Balance, Metitur Ltd, Finland) was conducted at 9:00, 13:00, and 17:00 hours on two consecutive days, and the sequencing of static and dynamic balance tests were randomized. Results were analyzed using the non-parametric one-way repeated Friedman test in SPSS version 18.0 (SPSS Inc., Chicago, IL, USA), and variable found to be significant were subjected to Wilcoxon post hoc testing. Results: Static and dynamic balance showed significant difference at the three times assessments (test at 9:00, 13:00, and 17:00) during circadian. In the post hoc test of static (anteroposterior distance, mediolateral distance and COP (center of pressure) velocity) and dynamic balance (performance time), 13:00 was the longer and faster than 9:00. Conclusion: These results indicated that control of postural balance is influenced by diurnal circadian rhythms, and confirm that control of postural balance is more effective and better performance in the 09:00 hours than 13:00 hours or 17:00 hours.

• Structural Engineering and Mechanics
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• v.69 no.3
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• pp.347-359
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• 2019

This paper aims to evaluate the behavior of Dorim-Goh bridge in Seoul, Korea, under static and dynamic loads effects by ambient trucks. The prestressed concrete (PSC) girders and reinforcement concrete (RC) slab of the bridge are evaluated and assessed. A short period monitoring system is designed which comprises displacement, strain and accelerometer sensors to measure the bridge performance under static and dynamic trucks loads. The statistical analysis is used to assess the static behavior of the bridge and the wavelet analysis and probabilistic using Weibull distribution are used to evaluate the frequency and reliability of the dynamic behavior of the bridge. The results show that the bridge is safe under static and dynamic loading cases. In the static evaluation, the measured neutral axis position of the girders is deviated within 5% from its theoretical position. The dynamic amplification factor of the bridge girder and slab are lower than the design value of that factor. The Weibull shape parameters are decreased, it which means that the bridge performance decreases under dynamic loads effect. The bridge girder and slab's frequencies are higher than the design values and constant under different truck speeds.

• The KIPS Transactions:PartC
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• v.15C no.2
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• pp.79-86
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• 2008

MANET(Mobile Ad hoc Network) is a collection of two or more nodes equipped with wireless communications and constrained by the factor of energy limitation. The running out of energy on some nodes may bring down the performance of network seriously. For solving the problems above, this paper uses completely separated Node-Disjoint multipaths from a source to a destination as many as possible. And, based on average, minimum or variance of energy values on the each multipath, the packets are distributed on paths. Generally, collecting methods for energy information can be classified into two main categories, Static and Dynamic. As the different energy values collected, the packet distribution methods are classified into six criteria, Static-Average, Static-Minimum, Static-Variance, Dynamic-Average, Dynamic-Minimum and Dynamic-Variance respectively. The performance of the packet distribution methods and that of AODV are compared by NS2 simulation.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.224-230
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• 2001

A numerical analysis for the gas lubricated flexure-pivot tilting pad journal bearing has been accomplished. The film pressure are obtained by Newton-Raphson method and the dynamic coefficients are evaluated by the pad assembly method. The effects of the pivot position of the pad on the static and dynamic characteristics are presented for three pads journal bearing with LBP. The optimum pivot positions for the static performance is different from that of the dynamic performance.