• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.243-246
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• 1999

The displacement current measuring system used for detecting the dynamic behavior of monolayers at the air-water interface is described. It basically consists of a film balance, a pair of electrodes connected to each other through a sensitive ammeter. Here, one electrode is suspended in air and the other electrode is the water, With Maxwll-displacement-current-measuring method, the phase transitions of Poly(λ-benzyl- L-glutamate)(PBLG) on a water surface were detected, Displacement currents generated during the compression of monolayers of PBLG on the surface of water were investigated. As results, the displacement pick was generated when the area per molecule was about 15 $\AA$$^{2}$ in low pressure, and tit was generarted when the area per molecule about 27$\AA$$^{2}$ in high pressure.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.474-478
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• 2004

A bushing is a device used in automotive suspension systems to reduce the load transmitted from the wheel to the frame of the vehicle. A bushing is a hollow cylinder, which is bonded to a solid steel shaft at its inner surface and a steel sleeve at its outer surface. The relation between the force applied to the shaft and the relative deformation of a bushing is nonlinear and exhibits features of viscoelasticity. A force-displacement relation for bushings is important for multibody dynamics numerical simulations. For the nonlinear viscoelastic axial response, Pipkin-Rogers model, the direct relation of force and displacement, has been derived from Lianis model and the sinusoidal input was used for Pipkin-Rogers model, and the affection of displacement with frequency change was studied with Pipkin-Rogers model.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1200-1202
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• 1993

There are many methods to investigate the physical properties of monolayers formed at the air-water interface. Among them, the displacement current method is appropriate for the investigation of the dynamic behavior of monolayers. The measuring system of displacement current method was constructed at home-made Kuhn type LB deposition apparatus using aluminium plate electrode. The currents induced by the dynamic motion of molecules were measured when the molecules were pressed by barrier. To verify the measuring system, we used 4-octyl -4'-(5-carboxy-pentamethyleneoxy)-azobenzene molecules which has two remarkable variations of surface pressure of monolayer at the air-water interface. We can detect the two peaks of displacement currents which shows that the orientations of molecules are changed greatly at the state of these two remarkable changes of surface pressure.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.1042-1048
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• 2016

This paper presents a lateral displacement restoring force control for the independently rotating wheelsets (IRWs) of shallow-depth subway systems. In the case of the near surface transit, which has recently been introduced, sharp curved driving performance is required for the city center service. It is possible to decrease the curve radius and to improve the performance of the straight running with the individual torque control. Therefore, the individual torque control performance of the motor is the most important point of the near surface transit. This paper deals with a lateral displacement restoring force control for sharp curved driving. The validity and usefulness of the proposed control algorithm is verified by experimental results using a small-scale bogie system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1271-1277
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• 2008

Competitive displacement of methylcellulose (MC) absorbed at the oil-water interface was investigated by interfacial composition, surface shear viscosity, or surface tension measurements. It was found that all emulsifiers could competitively displace the interfacial MC from the oil-water interface but their behaviors were different from each other. With Tween 20 added to MC emulsion (1 wt% MC, 10 wt% n-tetradecane, 20 mM bis-tris, pH 7), MC load was steadily decreased with increasing concentrations of the emulsifier, as confirmed by surface shear viscosity measurements; moreover, there was complete MC displacement from the emulsion droplet surface at high concentration (0.1 wt%). The oil-soluble Span 80 was found to show a synergism with MC at the interface, which resulted in higher MC load at relatively low emulsifier concentrations ($\leq$0.05 wt%). At a higher emulsifier concentration (0.1 wt%) limited MC displacement was observed. These results were well supported by surface shear viscosity measurements. With water-soluble SDS, MC load was decreased with increasing concentrations of the emulsifier. Unlike Tween 20, however, it was found that at high concentrations (> 0.1 wt%), there was still some MC remaining at the droplet surface. Surface tension measurements are suggestive of an interfacial complex between MC and SDS.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.115-118
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• 2005

A workpiece with a large surface area is likely to be uneven due to form error and waviness. These geometric disturbances can cause inaccurate micro shapes to be formed when micro features are micro-grooved into the surface and cause the resulting workpiece to fail to function as desired. Thus, real-time measurement and compensation is required to guarantee the form accuracy of micro features while machining a workpiece with a large surface area. In this study, a method is suggested for real-time measurement of geometric error for the micro grooving of a large flat surface using a laser displacement sensor. The measurements are demonstrated for the workpieces with large surface areas and the experimental results show that the waviness and form error are well detected.

• Journal of the Korean Applied Science and Technology
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• v.32 no.3
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• pp.522-527
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• 2015

We applied a displacement current measurement technique for the study of L-${\alpha}$-dilauryl phosphatidylcholine (DLPC) monolayer. Displacement current was generated at the DLPC monolayer on the water surface, while induced by compression and expansion of the monolayer. Generation of Maxwell displacement current (MDC) was observed when surface areas per DLPC molecule were approximately $200{\AA}^2$ and $40{\AA}^2$. We investigated MDC for monolayer compression cycles, and found that MDC reached the maximum at the molecular area, which was measured right before surface pressure began to increase during compression cycles. The monolayer surface morphology of Langmuir-Blodgett (LB) films was characterized using atomic force microscope (AFM). As a result, we measured the result from the microscopic properties shown in the AFM images of LB films that molecules in the monolayer were in good orientations and the thickness of the monolayer ranged from 5 to 10 nm.

• The Journal of Engineering Geology
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• v.33 no.2
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• pp.275-291
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• 2023

Global warming has made the polar regions more accessible, leading to increased demand for the construction of new resource-development plants in oil-rich permafrost regions. The selection of locations of resource-development plants in permafrost regions should consider the surface displacement resulting from thawing and freezing of the active layer of permafrost. However, few studies have considered surface displacement in the selection of optimal locations of resource-development plants in permafrost region. In this study, Analytic Hierarchy Process (AHP) analysis using a range of geospatial information variables was performed to select optimal locations for the construction of oil-sands development plants in the permafrost region of southern Athabasca, Alberta, Canada, including consideration of surface displacement. The surface displacement velocity was estimated by applying the Small BAseline Subset Interferometric Synthetic Aperture Radar technique to time-series Advanced Land Observing Satellite Phased Array L-band Synthetic Aperture Radar images acquired from February 2007 to March 2011. ERA5 reanalysis data were used to generate geospatial data for air temperature, surface temperature, and soil temperature averaged for the period 2000~2010. Geospatial data for roads and railways provided by Statistics Canada and land cover maps distributed by the North American Commission for Environmental Cooperation were also used in the AHP analysis. The suitability of sites analyzed using land cover, surface displacement, and road accessibility as the three most important geospatial factors was validated using the locations of oil-sand plants built since 2010. The sensitivity of surface displacement to the determination of location suitability was found to be very high. We confirm that surface displacement should be considered in the selection of optimal locations for the construction of new resource-development plants in permafrost regions.

• The Journal of Korean Physical Therapy
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• v.26 no.2
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• pp.97-103
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• 2014

Purpose: The aim of this study was to clarify the gender difference during standing balance in accordance with recruitment of abdominal muscles against sudden support surface translation. Methods: Twenty healthy males (n = 10, $26.50{\pm}3.54$ years, $170.60{\pm}6.30cm$, $72.80{\pm}5.69kg$) and females (n = 10, $24.40{\pm}2.63$ years, $163.00{\pm}4.97cm$, $52.10{\pm}4.41kg$) participated in the study. Each subject performed standing balance task on a platform, which moved in the anterior and posterior direction, with a total of 18 trials in three abdominal conditions (resting, hollowing, and bracing). We analyzed angular displacement of thoracic and lumbar spine and linear displacement of center of mass for evaluatione of spinal stability and standing balance, respectively. Results: Angular displacement of thoracic and lumbar spine and linear displacement of center of mass did not differ significantly between female and male in all conditions. Conclusion: Our results indicate that the ability to maintain spinal stability and standing balance were similar between male and female regardless of the abdominal contractile conditions and the direction of support surface translation.

• Geomechanics and Engineering
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• v.6 no.6
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• pp.561-575
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• 2014

Estimating seismic displacements has a great importance for foundations on or adjacent to slope surfaces. However, dynamic solution of the problem has received little attention by previous researchers. This paper presents a new analytical model to determine seismic displacements of the shallow foundations adjacent to slopes. For this purpose, a dynamic equilibrium equation is written for the foundation with failure wedge. Stiffness and damping at the sliding surface are considered variable and a simple method is proposed for its estimation. Finally, for different failure surfaces, the calculated dynamic displacement and the surfaces with maximum strain are selected as the critical failure surface. Analysis results are presented as curves for different slope angles and different foundation distances from edge of the slope and are then compared with the experimental studies and software results. The comparison shows that the proposed model is capable of estimating seismic displacement of the shallow foundations adjacent to slopes. Also, the results demonstrate that, with increased slope angle and decreased foundation distances from the slope edge, seismic displacement increases in a non-linear trend. With increasing the slope angle and failure wedge angle, maximum strain of failure wedge increases. In addition, effect of slope on foundation settlement could be neglected for the foundation distances over 3B to 5B.