• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.621-628
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• 2000

In this study, the influence of groundwater variation and surface settlement adjacent to the excavation site of subway station on $\bigcirc$$\bigcirc$ Gas station and the $\bigcirc$$\bigcirc$ building is analized. Measurement data of surface settlement, horizontal deformation and groundwater level are used to verify the results of Caspe analytical method and FLAC numerical analysis. Variation of groundwater level adjacent to the excavation site is modelled by the 3-D groundwater flow program, MODFLOW. The results of both the analytical method and the numerical method were quite close to the measurement data of surface settlement.

• Journal of the Optical Society of Korea
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• v.14 no.4
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• pp.409-414
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• 2010

This paper describes the surface form measurement of a spherical smooth surface by using single shot off-axis Fizeau interferometry. The demodulated phase map is obtained and unwrapped to remove the $2\pi$ ambiguity. The unwrapped phase map is converted to height and the 3D surface height of the surface object is reconstructed. The results extracted from the single shot off-axis geometry are compared with the results extracted from four-frame phase shifting in-line interferometry, and the results are in excellent agreement.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.3
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• pp.315-322
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• 2011

High-accuracy micropatterns such as V-shaped microgrooves are increasingly in demand for various engineering areas. And the technical trend goes for large surface areas in precision machining technology. So micropatterns with large surface areas are expected to play an increasingly important role in today's manufacturing technology In this study, we focused on developing machining technologies. First, a machine vision system for precise tool setting is developed. Second, an on-machine measurement (OMM) system for large-area measurement is implemented. And also software for tool path generation and simulation is developed. With these technologies we fabricated large-surface micropatterns in an electroless nickel-plated workpiece with single-crystal diamond tools and a 32-in, $675mm{\times}450mm$ mold with tens of V-and pyramid-shaped micropatterns.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.317-319
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• 2008

Traditionally, it is measured by using basin or empirical formula with meteorology data, while it does not represent the evaportransporation over a regional area. With the advent of improved remote sensing technology, it becomes feasible to assess the ET over a regional scale. Firstly, the IMAGINE ATCOR atmospheric module is used to preprocess for the MODIS imagery. Then MODIS satellite images which have been corrected by radiation and geometry in conjunction with the in-situ surface meteorological measurement are used to estimate the surface heat fluxes such as soil heat flux, sensible heat flux, and latent heat flux. In addition, the correlation coefficient between the derived latent heat and the in-situ measurement is found to be over 0.76. In the future, we will continue to monitor the surface heat fluxes of paddy rice field in Chiayi area.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04b
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• pp.338-342
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• 1999

It has been proven in previous work that rosin sizing agents are distributed relatively homogeneously on the outer surface of paper. Therefore, rosin sizing agents on paper surfaces can be characterized by macro domain measurement techniques with very thin layer from the surface. In this work, the role of rosin sizing agents on paper surface was investigated by comparing wettability from contact angle measurement with the chemical state of the outermost surface by the ESCA. Furthermore, the role of rosin on the surface of paper was discussed by the quantity of hydroxyl groups obtained from chemical modification with the TFAA-ESCA technique. It was found from the ESCA data that the fixing mechanism with soap-type rosin sizing is different from that with emulsion-type rosin sizing.

• Textile Coloration and Finishing
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• v.19 no.4
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• pp.38-46
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• 2007

Surface properties of the plasma treated fabric were changed while maintaining its bulk properties. Surface of plasma treated fabric take charge of enhanced adhesion by surface etching, surface activity. The water repellency coating Poly(Ethylene Terephthalate) fabric was treated with atmospheric pressure plasma using various parameters such as Argon gas, treatment time, processing power. Morphological changes by atmospheric pressure plasma treatment were observed using field emmission scanning electron microscopy(FE-SEM) and the zeta-potential measurement, contact angle measurement equipment. At the atmospheric pressure plasma treatment time of 150 sec, the power of 800W, the best wettability and peel strength were obtained. And we confirmed the possibility of industrial application by using atmospheric plasma system.

• Journal of Powder Materials
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• v.9 no.4
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• pp.251-260
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• 2002

In the viscosity measurement of PIM feedstock, slip correction methods require a number of experiments and produce a high level of error. In this study, a rotational rheometer with a parallel-discs configuration having different surface roughness was tried to minimize the effect of the slip phenomenon. Disc surface was prepared in 3 different roughness conditions - a smooth and 2 roughened surfaces. Results with the roughened surfaces were compared with the results obtained with a slip correction method. Relationship between powder characteristics such as size and shape and a surface roughness of the disc was examined for feedstock of 4 different powders with a same binder. As results, the effect of the slip phenomenon could be sufficiently minimized on the roughened surface in most cases. However, the effect of the slip phenomenon could not be sufficiently minimized for feedstock of a round-particular-shape powder and in the case of very narrow gap size.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.8
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• pp.361-364
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• 2005

In this paper, surface temperatures of ZnO arresters as a function of ambient temperatures and leakage currents were experimentally investigated. The variations of the leakage current was below 10 uA, which comes about $4.5\%$ of the normal leakage current. Temperature differences between the ambient and the surface of arresters were not shown until $150\%$ to the normal leakage current, and were remarkable over $200\%$. From the results, we deduced a couple of polynomials which enables the calculation of the leakage current by the measurement of surface temperature. Tests on used arresters have shown the same results as the experimental one. Also, we expect that an arrester diagnosis is possible by measuring the surface temperature of them after more studies on the effect of wind, moisture penetration, and arrester types.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.2
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• pp.104-109
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• 2011

I present a method of aspheric surface profile measurement using 2nd derivative of local area profile. This method is based on the principle of curvature sensor which measures the local 2nd derivative under test along a line. The profile is then reconstructed from the data on the each point. Unlike subaperture-stiching method and slope detection method, 2nd derivative method has strong points from a geometric point of view in measuring the aspheric surface profile. The second derivative terms of surface profile is an intrinsic property of the test piece, which is independent of its position and tip-tilt motion. The curvature is measured at every local area with high accuracy and high lateral resolution by using White-light scanning interferometry.

• Journal of Welding and Joining
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• v.20 no.1
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• pp.69-75
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• 2002

This study investigated the effect of the system parameters on penetration depth measurement using infrared temperature sensing system. The distance from focusing lens to detector was varied to diminish the error in measuring weld bead width. The effect of bead surface shape on measured surface temperature profile was evaluated using specimen heated by electric resistance. The measuring distance from laser beam was changed to optimize the measuring point. The results indicated that the monitoring device of surface temperature using infrared detector array was applicable to real time penetration depth control.