• Journal of The Korean Association For Science Education
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• v.23 no.4
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• pp.419-429
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• 2003

The developments of science education until the middle of the 20th century were often driven by personal ideas and achievements of some influential individual scientists (e.g. T. H. Huxley, H. E. Armstrong. L. Hogben, J. Conant). while that of the 2nd half of the 20th century can be characterized as collective efforts through various research grou ps of science educators (e.g. PSSC, HPP, Nuffield, SATIS). In this respect, John Tyndall(1820-1894), a physicist of the Victorian England best known as Tyndall's Effect, can be considered as one of the great scientists who made a big influence on science teaching and the popularization of science before science secured its place in school curricula. Tyndall worked as a research scientist at the Royal Institution of London, where various lectures and demonstrations of physical sciences were regularly performed for general public, and he was particularly famous for his fascinating physics demonstrations. In this study, we summarize his activities and achievements as a teacher as well as a popularizer of physics, illustrate some of his famous demonstrations and his ideas concerning physics teaching and discuss their implications to today's physics education.

• Journal of the Korean Mathematical Society
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• v.38 no.3
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• pp.523-559
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• 2001

To predict the fate of groundwater contaminants, accurate spatially continuous information is needed. Because most field sampling of groundwater contaminants are not conducted spatially continuous manner, a special estimation technique is required to interpolate/extrapolate concentration distributions at unmeasured locations. A practical three-dimensional estimations method for in situ groundwater contaminant concentrations is introduced. It consistas of two general steps: estimation of macroscopic transport process and kriging. Using field data and nonlinear optimization techniques, the macroscopic behavior of the contaminant plume is estimated. A spatial distribution of residuals is obtained by subtracting the macroscopic transport portion from field data, then kriging is applied to estimate residuals at unsampled locations. To reduce outlier effects on obtaining correlations between residual data which are needed for determining variougram models, the R(sub)p-estimator is introduced. The proposed estimation method is applied to a field data set.

• Smart Structures and Systems
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• v.21 no.3
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• pp.287-303
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• 2018

Applications of energy harvesting from mechanical vibrations is becoming popular but the full potential of such applications is yet to be explored. This paper addresses this issue by considering an application of energy harvesting for the dual objective of serving as an indicator of structural health monitoring (SHM) and extent of control. Variation of harvested energy from an undamaged baseline is employed for this purpose and the concept is illustrated by implementing it for active vibrations of a pipe structure. Theoretical and experimental analyses are carried out to determine the energy harvesting potential from undamaged and damaged conditions. The use of energy harvesting as indicator for control is subsequently investigated, considering the effect of the introduction of a tuned mass damper (TMD). It is found that energy harvesting can be used for the detection and monitoring of the location and magnitude of damage occurring within a pipe structure. Additionally, the harvested energy acts as an indicator of the extent of reduction of vibration of pipes when a TMD is attached. This paper extends the range of applications of energy harvesting devices for the monitoring of built infrastructure and illustrates the vast potential of energy harvesters as smart sensors.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.895-900
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• 2012

This paper aims to examine the effect of nanodroplets on pool-type absorption heat transfer enhancement and to find the relationship between the dispersion stability and the absorption performance. The concentrations of oil and surfactant are considered as the key parameters. $C_{12}E_4$ and Tween20 are used as the surfactants and N-decane oil is added to the $NH_3/H_2O$ solution to make the binary nanoemulsion fluids. Binary nanoemulsion fluids are dispersed by the ultrasonic vibrator and the stirrer under specific conditions. The dispersion stability of binary nanoemulsion fluids for each oil concentrations is evaluated from the droplet size and Tyndall effect analysis. The absorption performance of binary nanoemulsion fluids is compared with the result of dispersion stability. In addition, it is found that the binary nanoemulsion fluid is a strong candidate as a new working fluid for absorption applications.