• Korean Journal of Applied Biomechanics
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• v.29 no.3
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• pp.145-155
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• 2019

Objective: The purpose of this study was to compare the physical characteristics (bone mineral density, joint muscle strength) and running biomechanics between older adults and young adult runners to understand the changes of running strategy by aging. Method: Bone mineral density (Dual Energy X-ray Absorptiometry, USA) of lower lower extremity and muscle strength (Cybex Humac Norm [DEXA], CSMI, USA) were measured to identify the physical characteristics of 10 elderly (age: $67.70{\pm}3.30yrs$, height: $1.68{\pm}0.04m$, mass: $67.70{\pm}3.80kg$) and 10 young adults (age: $21.20{\pm}0.42yrs$, height: $1.73{\pm}0.06m$, mass: $72.11{\pm}4.15kg$). Running data was collected by using an instrumented treadmill (Bertec, USA) and 7 infrared cameras (Oqus 300, Qualisys, Sweden). Two-way repeated ANOVA analysis was used to analyze results at a significant level of .05 with Bonferroni post hoc analysis. Results: Compared to the young adult group, the elderly group showed statistically significant difference in physical characteristics and in running characteristics. Elderly runners showed lower BMD and muscle strength compared with young runners (p<.05). In the running parameters, elderly runners tend to show shorter contact time and stride length compared with young runners (p<.05). In the joint angles, elderly runners showed smaller range of ankle motion compared with young runners (p<.05). Finally, elderly runners showed lower level of joint moment, joint power, and GRF compared with young runners in each running speed (p<.05). Conclusion: The running behavior of the elderly performed periodic running was similar to many variables of young adults. However, there were noticeable differences found in the ankle joints and most kinetic variables compared with young adult runners. This discrepancy may propose that elderly runners should consider appropriate running distance and intensity in the program.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.69-81
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• 2005

In this study using two-dimensional system of the analysis of image, when normal males in their twenties who have normal foot and step with heel first are walking and running, they who are wearing running shoes or barefoot are testing and comparing the exchange factors of heel control. There are following results of this test by verifying them with T-Test. 1) When they are running, there are two big different gap which is $6.05^{\circ}$ between barefoot and wearing the running shoes. The former is $174.79^{\circ}{\pm}6.31$ and the latter is $180.84^{\circ}{\pm}4.69$. But it is not statistically significant. The angle of first step with heel is $100.42^{\circ}{\pm}3.95$ with barefoot and $93.97^{\circ}{\pm}094$ with wearing the running shoes. In this case, it is statistically significant(p<.01) 2) When they are running, the angle of the Achilles' tendon has different gap which is $5.24^{\circ}$ between barefoot and wearing the running shoes. The former is $179.70^{\circ}{\pm}4.23$ and the latter is $184.94^{\circ}{\pm}4.09$. It is not statistically significant. The angle of minimal step with heel is $96.30^{\circ}{\pm}3.07$ with barefoot and $90.84^{\circ}{\pm}0.44$ with wearing the running shoes. In this case, it is statistically significant(p<.01). 3) In the angle of the Achilles' tendon and the angle of first step with heel, when they are walking, the angle of the Achilles' tendon has different gap which is $1.81^{\circ}$ between barefoot and wearing the running shoes. The former is $6.39^{\circ}{\pm}0.83$ and the latter is $8.20^{\circ}{\pm}1.85$. It is not statistically significant. The angle of first step with heel is $2.32^{\circ}{\pm}0.51$ with barefoot and $3.22^{\circ}{\pm}1.44$ with wearing the running shoes. It is not statistically significant. 4) In the angle of the take-off of Achilles' tendon, when they are walking, the angle of the take-off of Achilles' tendon has different gap which is $3.88^{\circ}$ between barefoot and wearing the running shoes. The former is $177.62^{\circ}{\pm}8.78$ and the latter is $173.74^{\circ}{\pm}16.31$. It is statistically significant(p<.05). Therefore, they are running, the angle of the take-off of Achilles' tendon is $178.37^{\circ}{\pm}19.28$ with barefoot and $171.26^{\circ}{\pm}12.18$ with wearing the running shoes. It is statistically significant(p<.05).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1903-1914
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• 2011

In this paper, we propose vehicle running characteristic simulator. The developed simulator is configured by two induction motors which are directly coupled with each other. One motor is to simulate the vehicle drive and another motor is to simulate the vehicle dynamic load including running resistance, gradient resistance and adhesive characteristics between rail and wheel. The running characteristics of vehicle are modeled by numerical formulas. These are programed by software of embedded controller. Thus, it is possible to change several running characteristics during the running test freely and instantly. To evaluate the feasibility of the simulator, the experiments on slip and adhesion coefficient are performed. Additionally the adhesion control and speed control of vehicle are tested with simulator. Experimental results show that the simulator can produce the driving characteristics similar to the vehicle system.

• Knowledge Management Research
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• v.11 no.1
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• pp.37-50
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• 2010

Bioharmaceutical technologies have consistently been areas in which large licensing agreements have been negotiated. However, there are very limited informations in the open literature on how its running royalty rates are determined and no specific methods are yet provided. The purpose of this study is to suggest an appropriate method for the estimation of running royalty of bioharmaceutical technology in licensing agreements. Here distribution of risk-adjusted operating margins are obtained by simulation using statistics of success rates in the stage of clinical trials and profit margins. Three factors based on technology, business and license legal terms are considered and combined as licensing competitiveness level. Finally, reasonable running royalty is estimated by combining simulated distribution and licensing competitiveness level. This suggested method is expected to practically useful for licensor to establish an appropriate running royalty rate for licensing.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.20-26
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• 2005

A running-profile generation method has been developed that efficiently generates the minimum-energy running profile, even in railway lines which have complicated speed limit sections. In the developed method, the problem of minimizing energy consumption is formulated as a resource allocation problem by dividing a running profile into several blocks, and is solved by the incremental method. A concept of Uni-Braking Block (UBB) which has only one brake section within it is introduces for the formulation. This paper proposes a specific method for running profile in the railway lines by using UBB. And proposes the algorithm to generate the running profile with minimum-energy.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.745-750
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• 2004

For the safety of railway, it should be evaluated for the running safety by measuring the derailment coefficient. Although railway has run the fixed and maintained rail, some of railway is derailed. This report shows the results that performed the static load test, wheelset manufacturing for test, main line running test on the basis of the derailment theory and experience. It is executed main line test into more than 80km/h for estimating the curving performance and running safety of Gwangju EMU. As the test results, could confirm the curving performance and running safety of Gwangju EMU from the results of the wheel unloading, lateral force, derailment coefficient etc. Derailment coefficient was less than 0.8, and lateral force allowance limit and wheel load reduction ratio were enough safe.

• International Journal of Railway
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• v.3 no.2
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• pp.68-72
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• 2010

Railway vehicles equipped with semi-active suspension system can improve the ride quality of car bodies. Semi-active suspension system is usually applied onto high speed train, and therefore higher running safety requirement is desirable. The influence of semi-active suspension system on safety of vehicles running on straight line and curve line is studied, and the influences of sky hook damping coefficient and system time-delay on operational safety of cars fitted with semiactive suspension system is analyzed. The results show that in vehicles equipped with semi-active suspension system, while the vibration of car body is decreased, the running safety of cars is not affected to any significant degree. As a result, the ride quality is much improved with negligible deterioration of the running safety of cars.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.359-365
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• 2014

A study was conducted to investigate the possible effects of fatigue which was resulted from increased running time on the stability during a prolonged run. The purposes of this study were twofold: first, to determine the discrete and non-linear variability of GRF (ground reaction force) components between running times to know the body stability, and second, to determine the pattern between discrete and non-linear variability. Nineteens healthy young adult males served in this study as subjects who ran at their preferred running speed. GRF data for twenty strides were collected at 5, 65, and 125 minutes during run. Variance coefficient and Lyapunov Exponent techniques on the GRF data were used to calculate variability index for each of the running time conditions. There were no difference between discrete variabilities of three components of GRF, but non-linear variability of the Fz component of GRF was decreased by increasing running time (p<.01). No relationship was found between discrete and non-linear variability.

• International Journal of Railway
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• v.2 no.4
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• pp.147-151
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• 2009

Railway vehicles equipped with semi-active suspension system can improve the ride quality of car bodies. Semi-active suspension system is usually applied onto high speed train, and therefore higher running safety requirement is proposed. The influence of semi-active suspension system on safety of vehicles running on straight line and curve line is studied, and the influences of sky hook damping coefficient and system time-delay on operation safety of cars fitted with semiactive suspension system is analyzed. The results show that the vehicles equipped with semi-active suspension system, not only the vibration of car body is decreased, it can also give little influence on running safety of cars, as a result, it will not endanger the running safety of cars.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1439-1440
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• 2010