• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.2 no.1
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• pp.115-125
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• 2007

Objectives : The limited number of studies to date have mainly focused on the effect of obesity on the characteristics of plantar foot pressures. This study is designed to find the correlation between plantar pressure and obese index. Methods : This study assessed the body composition of 30 obese women using bioelectrical impidence analysis and Gaitview AFA-50. The static and dynamic plantar pressure was determined from electronic footprints captured using a capacitive pressure distribution platform during standing and walking. The data were analysed by independent t-test and Pearson Correlation. Results : Positive correlations were noted between body weight, body mass index(BMI), waist circumference(WC), waist-hip ratio(WHR) and difference of fore and rear plantar pressure. And negative correlations were noted between body weight, BMI, WC, WHR and difference of left and right plantar pressure. Conclusions : The findings of this pilot study suggest that body composition influences the waight distribution in overweight and obese subjects.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.228-233
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• 2002

The transition between bridge or tunnel and plain track has different rail pressure and distributed stress on formation. This paper shows distribution of rail pressure on transition at which spring stiffness are changed. By this study, it is revealed that the changing into relatively high stiffness causes increased rail pressure visibly and draw up dynamic track force. A medium stiffness structure and reinforced rail could be effective for reducing track force on the transition.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.945-950
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• 2001

Vacuum interrupters that is used in various switchgear components such as circuit breakers, distribution switches, contactors, etc. spreads the arc uniformly over the surface of the contacts. The electrode of vacuum interrupters is used sintered Cu-Cr material satisfied with good electrical and mechanical characteristics. Because the closing velocity is 1-3m/s, the deformation of the material of electrodes depends on the strain rate and the dynamic behavior of the sintered Cu-Cr material is a key to investigate the impact characteristics of the electrodes. The dynamic response of the material at the high strain-rate is obtained from the split Hopkinson pressure bar test using cylinder type specimens. Experimental results from both quasi-static and dynamic compressive tests with the split Hopkinson pressure bar apparatus are interpolated to construct the Johnson-Cook equation as the constitutive relation that should be applied to simulation of the dynamic behavior of electrodes. To evaluate impact characteristic of a vacuum interrupter, simulation is carried out with five parameters such as initial velocity, added mass of a movable electrode, wipe spring constant, initial offset of a wipe spring and virtual fixed spring constant.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.05a
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• pp.245-251
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• 2004

This paper discuss the conditionally sampled actual wind pressure distributions causing peak quasi-static wind loads in the large span roofs using the wind pressures at many locations on dome models measured simultaneously in a wind tunnel. The actual extreme pressure distributions are compared itk load-response-correlation (LRC) method and the quasi-steady pressure distributions. Based on the results, the reason for the discrepancy in the LRC pressure distribution and the actual extreme pressure distribution are discussed. Futhermore, a brief discussion is made of the equivalent static wind load estimation for the large span roofs.

• Physical Therapy Korea
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• v.23 no.4
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• pp.27-37
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• 2016

Background: In previous studies regarding flexible pes planus, Foot orthosis, special shoes have been used as interventions for correcting malalignment and intrinsic muscles strengthening exercise have been regarded as interventions for foot function and supporting medial longitudinal arch during walking. However, some recent studies reported that strengthening extrinsic muscles as well as intrinsic muscles is more effective and active intervention for flexible pes planus. In particular, the tibialis posterior muscle of foot extrinsic muscles plays essential roles in maintaining the medial longitudinal arch during dynamic weight bearing and balance. In addition this muscle acts longer than other supination muscles during the stance phase in the gait cycle. Objects: This study aimed to investigate the effect of foot intrinsic muscle and tibialis posterior muscle strengthening exercise for plantar pressure and dynamic balance in adults with flexible pes planus. Methods: 16 young flexible pes planus adults (7 males, 9 females) were recruited and were randomized into two groups. The experimental group performed foot intrinsic muscle and tibialis posterior muscle strengthening training, the control group performed only foot intrinsic muscle strengthening training. All groups received strengthening training for 30 minutes five times a week for six weeks. Results: The experimental group had significantly lower plantar pressure of medial heel area than the control group in stand (p<.05). The experimental group had significantly higher dynamic balance ability than control group (p<.05). Conclusion: The results of this study provide evidence to suggest that foot intrinsic muscle and tibialis posterior muscle of extrinsic muscle strengthening exercises may improve plantar pressure distribution and dynamic balance ability in adults with flexible pes planus.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.19 no.1
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• pp.49-54
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• 2013

Background: The purposed of this study is to examine the static and dynamic plantar foot pressure in chronic low back pain patients and normal adults. Methods: The subjects were divided into a group of 30 patients with chronic low back pain and a control group of 30 healthy persons. While static posture and dynamic posture at comfortable walking speeds, the low back pain group and the control group measured their plantar foot pressure and the trajectory of their center of pressure (COP) using the Matscan(R) system. Independent t-tests were measured to compare differences in plantar foot pressure characteristics between the left side and right side of the low back pain group and the control group. Results: In the comparison of differences in plantar foot pressure characteristics between the left side and right side of the low back pain group and the control group, the anteroposterior (AP) displacement of COP showed significant differences (p<.05). Although the low back pain group and the control group did not show any significant differences in leg length, weight distribution, mediolateral (ML) displacement of COP, static contract area, dynamic contract areas (p>.05), increases in the contract area values were shown in the hind foot in general. Conclusion: In this study, it was shown that patients with chronic low back pain were walking with short AP displacement of the COP as a compensatory action to avoid pain.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1993.12a
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• pp.63-69
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• 1993

In this paper the characteristics of Hydrostatic Bearing of piston of cylinder are investigated . The dynamic characteristic equations of piston considering both parallel and rotational motion and time dependent modified Reynolds Equation are analyzed and the dynamic pressure distribution of oil film is numerically calculated by perturbation method and finite difference method. and the atatic analysis is carried out. so, the influence of design parameter of piston on the characteristic of bearing is analyzed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.1872-1885
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• 1991

The analysis of electromagnetic forming process consists of the analysis of the electric circuit and the dynamic deformation analysis. The purpose of the electric circuit analysis is to calculate the magnetic pressure and to apply it to the deformation analysis. Some investigators performed the analysis assuming the pressure distribution in longitudinal direction. However there was a difference between the calculated and experimental results. The difference mainly came from the assumption of the pressure distribution. One must know the magnetic field distribution in an actual situation for the analysis to be less erroneous. In this work the electromagnetic field analysis was performed by the finite element method to obtain a more realistic pressure distribution. A better agreement between the calculated and experimental results was obtained. It became possible to predict the deformation behavior of the workpiece of finite length.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.852-858
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• 2007

This paper investigates the dynamic characteristics of a tilted HDD spindle system with fluid dynamic bearings (FDBs). Tilting motion of a HDD spindle system may be caused by improper manufacturing tolerance, such as imperfect cylindricity between shaft and sleeve of FDBs, imperfect perpendicularity between shaft and thrust as well as the gyroscopic moment of the unbalanced mass of the rotating part. Tilting motion may result in the instability of the HDD spindle system and it may increase the disk run-out to limit memory capacity. This research proposes a modified Reynolds equation for the coupled journal and thrust FDBs to include the variable film thickness due to the cylindricity and the perpendicularity. Finite element method is used to solve the Reynolds equation for the pressure distribution. Reaction forces and friction torque are obtained by integrating the pressure and shear stress, respectively. The dynamic behavior is determined by solving the equations of a motion of a HDD spindle system in six degrees of freedom with the Runge-Kutta method to study whirling and tilting motions. This research shows that the cylindricity and the perpendicularity increase the tilting angle and whirl radius of the rotor.

• Tribology and Lubricants
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• v.8 no.2
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• pp.73-79
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• 1992

The pressure distribution between the piston pad and the cylinder wall is analyzed to reduce the friction and to get the dynamic stability in the low friction piston. The calculated results indicate that the rectangular pad may reduce the friction in comparison to the square one. And the low friction piston can be stabilized when the pressure difference between the top and bottom of the piston skirt is very small.