• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.218-223
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• 2011

Seated human subjects have been exposed to vertical vibration so as to investigate six-axis biodynamic response. Sixteen males were exposed to random vertical vibration in the frequency range(3~40Hz) at one vibration magnitude(0.224m/$s^2$ r.m.s.). Forces were measured in the vertical, fore-and-aft, lateral, roll, pitch and yaw direction on the seat. The median of cross-axis apparent mass magnitude in the fore-and-aft direction could reach up to 20% of the apparent mass magnitude at resonance frequency. And the median of apparent eccentric mass magnitude in the roll direction could reach up to 15% of the apparent eccentric mass magnitude in the pitch direction at resonance frequency. But cross-axis apparent mass in the lateral direction and apparent eccentric mass in the yaw direction showed very small.

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.333-338
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• 1997

Abnormal intraosseous flow and pressure in trabecular bone could cause various pathological conditions such as osteonecrosis and osteoarthritis. Characteristics of intraosseous fluid flow and pressure generation in porous trabecular bone can be significantly affected by the permeability. Factors which determine the permeability could be the porosity and apparent density of trabecular bone. However, there is little data on the permeability and the relationship among the permeability. porosity, and apparent density of trabecular bone. In this study. the permeability. porosity, and apparent density of human lumbar vertebral trabecular bone were experimentally measured. Also, a power relationship among the permeability, porosity, and apparent density was investigated to understand effects of the porosity and apparent density variations on the permeability of trabecular bone based on Kozeny-Carman equation. A near linear relationship between intraosseous fluid flow and time indicated that the fluid phase flowed through the pores in trabecular bone is governed by the permeability. The permeability of trybecular bone was found to have a significant power relationship with the porosity and apparent density (r: 0.84 and $\textit{p}$< 0.0005). The power relationship could be useful to determine the permeability of trybecular bone after measuring the apparent density and porosity.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.8
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• pp.645-650
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• 2003

This paper introduces attempts to obtain the 'representative'characteristics of the apparent mass (or dynamic mass) of seated Korean subjects under vertical vibration. Individual responses of driving-oint apparent masses obtained from forty one Korean subjects are illustrated. Four kinds of vibration levels and three different sitting postures are selected to collect the characteristic responses of each subject. Those individual responses are used to estimate the 'mean'apparent mass, which may be expected to be a representative model to Korean subjects. Several interesting features of the estimated apparent mass are suggested and compared to those of ISO 5982.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.5
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• pp.509-512
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• 1991

Rheological property and apparent viscosity(η)of several semi-solid foods were measured with extrusion capillary viscometer. Apparent viscosities of several semi-solid foods ranged from 0.2714 Pa.s to 2.6453 Pa.s Rheological property of spread type semi-solid foods was pseudoplastic (with yield value). Especially, as the moisture content and temperature of Chungkook-jang spread increased, apparent viscosity decreased. On the contrary, as the added soybean oil content of Chungkook-jang spread increased, apparent viscosity also increased.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.3
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• pp.352-363
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• 1999

Target detection by the infrared imager depends on the apparent temperature difference between the target and the background, so it is essential to predict apparent temperature variations for this purpose. In this study, thermal analysis program Including conduction, convection and radiation is developed and applied to a representative geometry adequate for examining the apparent temperature characteristics. The results show that the longwave emissivity in association with the background temperature affects the apparent temperature strongly but does not affect the physical temperature. It is revealed that the background temperature plays a role of tuning the apparent temperature. As the longwave emissivity decreases, the apparent temperature decreases when the target is hotter than the background, whereas it increases in the reversed situation. These findings imply that an effective surface treatment, such as painting of a less emissive material, may provide a less detection probability and contribute to preventing the target from being detected at night.

• Journal of IKEEE
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• v.23 no.1
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• pp.318-321
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• 2019

The apparent soil resistivity is used for estimating multilayer soil parameters, such as, layer's depth and soil resistivity. The apparent soil resistivity can be measured, and also can be calculated if soil parameters are given, becacuse the apparent soil resistivity is a function of these parameters. Therefore, any optimization algorithms can be used to find these parameters which make the calculated apparent soil resistivity close to the measured one. The equation for calculating the apparent soil resistivity is complicated and time consumed, because it is composed of an infinite integral which includes a zero order Bessel's function of the first kind. In this paper, a fast algorithm for calculating the apparent soil resistivity of horizontal multilayer earth structure has been presented using complex image method.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.10
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• pp.897-904
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• 2011

When whole-body is exposed to vertical vibration, asymmetry shape of human body affects the response on the translational(fore-aft, lateral, vertical) and rotational(roll, pitch, yaw) motion. While the translational motion has been studied with various titles, it has been rare to study the rotational motion of human body exposed to vertical excitation because of lack of experimental equipment. This study was performed by using a 6-axis force plate installing strain gage type sensors for the rotational response. Sixteen male subjects were exposed to vertical vibration on rigid seat in order to investigate apparent mass of three translational motion and apparent eccentric mass of three rotational motion. Random signal was generated to make excitation vibration which was on an effective frequency range of 3~40 Hz, and magnitude of 0.224 m/$s^2$ r.m.s. The frequency range and magnitude used was selected for the vibration of passenger vehicle on idling condition. As the result, cross-axis apparent masses of fore-and-aft and lateral direction were not significant showing 20 % and 3 % of vertical apparent mass relatively. And apparent eccentric mass of pitch motion was dominant when compared to that of roll and yaw motion, which is reasoned by asymmetry direction of human body sitting on a seat.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.822-826
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• 1994

Effects of concentration(6-9%, db) , heating temperature (80-95$^{\circ}C$), cooking time (10-50min) and heating method (continuous and instantaneous) on the apparent viscosity of cowpea sediment dispersions at 6$0^{\circ}C$ were investigated. The instantaneous heating resulted in higher apparent viscosity than continuous heating regardless concentrations and heating temperatures. The activation energy of the increase rate constant of the apparent viscosity was about 8 kcal/mole. The apparent viscosity of the cowpea sediment dispersion heated to 95$^{\circ}C$ and held for 20 min showed a linear relation with the 20 min height at 92.5$^{\circ}C$ by viscoamylograph.

• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.64-69
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• 2013

For power system protection, the distance relay settings are important. Apparent factor is a necessary parameter in distance relay settings. Apparent factors have to be calculated when setting the distance relays and doing the resetting in case of configuration change in power system. The problem is that the current method to calculate apparent factor requires tools and plenty of time to do fault analysis and this method is complex especially in case of configuration change. Therefore this paper proposes a fast algorithm to calculate apparent factor without the fault analysis. Test results prove that this algorithm is simple and accurate by simulation.

• International Journal of Advanced Culture Technology
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• v.7 no.4
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• pp.268-273
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• 2019

The apparent soil resistivity is used for estimating multilayer soil parameters, such as, layer's depth and soil resistivity. The soil parameters are estimated by continuously revising those parameters until the error between the measured and calculated apparent soil resistivity reaches to allowable level. The equation for calculating the apparent soil resistivity is complicated and time consumed, because it is composed of an infinite integral which includes a zero order Bessel's function of the first kind. In this paper, a fast algorithm for calculating the apparent soil resistivity of horizontal multilayer earth structure is proposed using exponential sampling method.