• Journal of Environmental Science International
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• v.10 no.5
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• pp.323-327
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• 2001

A new method is developed to estimate the evaporation of water from a surface with high accuracy and resolution. The principle of new method is to detect a weight change of buoyant weight according to a change in water level of Class A Pan mesured by the use of a strain-gauge load cell. Field test of evaporation recording new instrument was carried out at Suwon for 10 days July 1999. It is possible in field observation to measure hourly evaporation amount by newly developed evaporation recording instrument in Class A Pan against strong solar radiation. Present study provide a possibility of domestic high accuracy instrument development below than 0.1mm water level measurement accuracy. If there is low humidity and high wind speed conditions which is possible to evaporate from water surface during night time. And it needs continuous study to understand between meteorological elements and latent heat effect at ground level by field observation study using high accuracy evaporation recording instrument.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.907-910
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• 1995

Though SLA(Stereolithography Apparatus) is being recognized as an innovative technology, it still can not be used to fully practical applications since it lacks of dimensional accuracy compared to conventional processes. In SLA, the accuracy of cured part depends upon the set of process parmeters. In order to improve the accuracy of SLA, this paper quantitatively evaluates how largely each process parameter of SLA contributes to the part accuracy and estimates the optimal set of process parameter which minimizes the dimensional errors of the test part, "letter-H" part. For this purpose, we use ANOVA(analysis of variance) and S/N(signal-to-noise)ratio of Taguchi method.hi method.

• Korean Journal of Geomatics
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• v.3 no.2
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• pp.107-114
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• 2004

The National Geographic Information Institute (NGII) in korea, through the National Geographic Information System (NGIS) Program, has prepared to generate and disseminate digital elevation data for Korea. This is a pilot research to propose a policy for production, maintenance, and supply of Korea Digital Elevation Data(KDED). Customer demands for accuracy and resolution of DEM was surveyed through a questionnaire. In order to investigate the quality, the technical efficiency and the production cost, a tentative DEM in a small test site was generated based on digital topographic maps (original paper map scale 1:5,000), analytical plotter, and LIDAR. The Accuracy standard for KDED was derived based on source data generation methods. As a result of this research, a uniformly spaced grid model was recommended for KDED. Its preferable grid space is 5m in urban areas and its vicinity, and 10m in field and mountainous area. LIDAR has been valuated as a proper KDED generation method fulfilling customers' demands for the accuracy.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.8
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• pp.856-867
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• 1990

In this paper, the convergence and the learning accuracy of the back-propagation (BP) method in neural network are investigated by 1) analyzing the reason for decelerating the convergence of BP method and examining the rapid deceleration of the convergence when the learning is executed on the part of sigmoid activation function with the very small first derivative and 2) proposing the modified logistic activation function by defining, the convergence factor based on the analysis. Learning on the output patterns of binary as well as analog forms are tested by the proposed method. In binary output patter, the test results show that the convergence is accelerated and the learning accuracy is improved, and the weights and thresholds are converged so that the stability of neural network can be enhanced. In analog output patter, the results show that with extensive initial transient phenomena the learning error is decreased according to the convergence factor, subsequently the learning accuracy is enhanced.

• Korean Journal of Child Studies
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• v.24 no.2
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• pp.1-14
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• 2003

In this test for the effect of misinformation and mental reinstatement on accuracy of recall in children, misinformation or neutral informations was presented to each of 80 five- and 80 nine - year - old children(Total : 160). Two days later they were asked to recall original information in one of two conditions; free recall or mental reinstatement. For 5-year-old children, mental reinstatement enhanced memory performance and increased the accuracy despite the presentation of misinformation. For 9-year-old children, there was no significant difference between free recall and mental reinstatement condition. For younger children, mental reinstatement may be an effective way of enhancing memory performance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.4
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• pp.41-47
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• 2009

This research deals with evaluation of machining accuracy for Parallel Kinematic Machine Tool(PKMT) applied parallel type robot system with high precision and stiffness. For this purpose, machine simulation is carried out to foreknow collision and interference between workpiece and tool. Furthermore, on the basis of machine simulation data, PKMT is manufactured. Machining accuracy such as cylindricity straightness, squareness, parallelism circularity, concentricity pitch error and yaw error, is measured by using coordinate measuring machine. Test piece for evaluation of machining accuracy is designed and manufactured under the standard of ISO 10791-7.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1007-1010
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• 2002

The accuracy of high speed feeding type laser cutting M/C is the major factor directly concerned with the accuracy of the processed work, and the feed errors of feed system make the machining errors of work directly on processing. In this point, this study focused on the generative elements in feed errors of laser cutting M/C when operating its laser head. In order to improve the accuracy of this machining center, feed errors are measured by a laser interferometer.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.1
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• pp.9-17
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• 2006

The thrust measurement systems(TMS) with high accuracy are required in rockery, according to develop the high precise guided space vehicle. For obtaining high accuracy, the basic concepts and the necessary technology which have been acquired through many experiences of TMS are summarized, and the design methodology for practical use in ADD is presented. In this paper, the parameters against accuracy of TMS are discussed, and the improving methods are suggested. Through this application example, the design methodology of ADD is shown its superiority in TMS.

• Journal of KIBIM
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• v.3 no.2
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• pp.1-9
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• 2013

Currently, various studies and applications related BIM based quantity take-off have been attempted, because of the accuracy of cost estimating and reliability by using the BIM model information in automatical calculation. Finishing works that have a large number of various types and materials need the higher accuracy and reliability on the BIM-based quantity take-off. Therefore, this study compared and analyzed 2D and 3D based quantity through Test-bed and determine the cause of the quantity difference. This verified the accuracy and efficiency in the BIM-based quantity take-off for finishing works. Also this study has been proposed opinions for calculating the exact BIM-based quantity take-off.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.387-392
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• 2002

It is very important to measure linear cycle plane positioning accuracy of NC lathes as they affect those of all other machines machined by them in industries. For example, if the linear cycle plane positioning accuracy of each axes directions is bad, the accuracy of works will be wrong and the change-ability will be bad in the assembly of machine parts. In this paper, computer software systems are organized to measure linear displacements of ATC(Automatic tool changer) of NC lathes using linear scale and time pulses comming out from computer in order to get data at constant time intervals from the sensors. And each sets of error data gotten from the test is expressed to plots by computer treatment and the results of linear cycle plane positioning error motion estimated to numerics by statistical treatments.