• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.250-252
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• 1996

In this paper, the principle of operation. the part characteristic, characteristic of component movement, analysis are carried out for camcoder iris assembly which is one of the important element component in Video large projection TV instrument, and some Know-how for development of element component is also included. The magnetic field circuit for the small and simple structure with low power consumption is introduced and new materials of yoke for small motor system is suggested. Especially, the relation with remained magnetic field and operation duration time is analyzed by experimental results. Some problems of nonlinear torque characteristics include to obtain the simple and low cost structure in domestic production of element component is analyzed. Furthermore, development procedure is suggested for iris assembly and some methods to reduce the burr with some check points for small precise accessories are explained.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.5
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• pp.571-578
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• 2005

Stresses of main stop valve and control valve casings for the steam turbines of power plants are analyzed by the finite element method. The stress intensity is obtained to check the results on the basis of the design criteria of ASME boiler and pressure vessel code. To verify accuracy of the finite element analysis. analyzed stresses are compared with those measured during the hydrostatic pressure test. Stress category drawings. which play an important role in evaluating casting defects, are produced from the analysis results, and important points in casting of the valve casings are discussed in terms of the stress category.

• Journal of Advanced Marine Engineering and Technology
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• v.8 no.1
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• pp.37-48
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• 1984

For the designing propulsion shafting of ship, shaft diameters are usually calculated according to the Society's rules and other scantlings such as a shaft length, coupling and taper parts, etc., are decided according to calculated diameters. And then, the torsional vibration, the lateral vibration and shaft alignment should be reviewed to check whether the resonance points of torsional or lateral vibration appear within the normal operating speed range and the shaft alignment is reasonable. If the results of calculations are unsatisfactory, this process should be repeated until the final condition is determined and the process of this work takes much time to carry out. To simplify the above tedious processes, authors have developed a computer program to fulfill the above design processes at once. This program takes aim at reducing the manual calculating work associated with the propulsion shafting of ship. To confirm the availability of developed computer program, several propulsion shaftings which are driven by diesel engines, have been analysed. The results calculated by authors developed computer program show comparatively good agreements with those of the actual propulsion shafting.

• Journal of Korean Society for Quality Management
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• v.32 no.2
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• pp.132-153
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• 2004

CUSUM control charts are widely used to monitor processes with small shifts. CUSUM control charts are, however, less effective in detecting for recurring cycles or frequent small shifts in the processes. With Shewhart control charts, we have applied the variety of run rules to check the stability of process in addition to the situations that some points fall outside the control limits. In this paper, we propose the Z -CUSUM control chart for monitoring the process with recurring cycles or frequent small shifts by use of the zone concept as like the Shewhart control charts.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.4 no.3
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• pp.12-24
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• 1995

Various surface grinding experiments using resin bonded diamond abrasive wheels are carried out for tungsten carbide materials in order to minimize the damage on the ground surface and to purse the precise dimension compared to conventional grinding machine. When grinding quality is constant, theoretical grinding effect is changed according to the speed of workpiece. Accordingly, grinding forces, which are Fn, Ft, were analyzed for the machining processes of tungsten-carbide material to obtain optimum grinding conditions. Brief investigation is carried out to decrease the dressing efficiency of resinoid bonded diamond grinding wheel to grind tungsten-carbide. Truing is also carried out to provide a desired shape on a wheel or to correct a dulled profile. High quality in dimensional accuracy and surface are often required as a structural components, therefore 3-points bending test is carried out to check machining damage on the ground surface layer, which in one of sintered brittle material. From this experimental study, some useful machining data and information to determine proper machining condition for grinding of tungsten-carbide materials are obtained.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.305-309
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• 2006

SAR (Synthetic Aperture Radar) technology, which is not influenced by cloud cover because of using electromagnetic wave of long wavelength, has an advantage in mapping the earth. NASA, recognizing these strong points of SAR, launched SRTM (Shuttle Radar Topography klission), and acquired the topographic information of the earth. SRTM and NED (National Elevation Data) of USGS were used for the research and vegetation height map was produced through differentiating the two data. Correlation between SRTM-NED and planting year was analyzed to see the relationship. Strong correlation was detected and it shows the feasibility of estimating timber age and eventually creating timber age map from SRTM-NED. Additional analyses were conducted to check if the linearity is influenced by regional characteristics and forest uniformity. As results, the correlation between SRTM-NED and timber age is influenced by roughness of the terrain. Overall, this paper shows that timber age estimation using SRTM and NED can be sufficiently practical.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1870-1875
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• 2006

This study was carried out to investigate the applicability of SAC-SMA model with parameters which were derived from analytical relationships proposed by Koren etc. (2000), with various data of soil properties in a basin. The studied basin is Yongdam dam basin and the daily runoff with 2003-year hydrological data was simulated. Simulated runoff results were compared with those measured at three check points(Chuchun, Donhyang and Yongdam) and analyzed through the statistical techniques such as VE(Volume Error), RMSE(Root Mean Squared Error) and CORR(Correlation). As a result of analyses, the good agreement was obtained between simulated and measured results.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.3-7
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• 1999

The images of the meteorological satellite NOAA contain geometrical distortions caused by its ambiguous position, its vibration, its sensor's movement, and so on. Geometric correction of satellite images is one of the most important parts in many remote sensing as the primary processing. Ground control points (GCP's) are necessary to check the accuracy of geometric correction and used for precise geometric correction. In this paper, a method for automatically selecting the residual error is presented. Calculating the effective angle and residual errors vector using the succeeded matching GCP's, precise geometric correction using an affine transformation is applied to systematically a corrected image. And the error is decreased by an affine transformation. The above enable the geometric correction of high quality.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.3
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• pp.227-233
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• 2011

The ultrasonic guided wave phased array using magnetostrictive patch transducers is proposed. The magnetostrictive transducer has received much attention because it is cost-effective and capable to generate ultrasonic waves with a simple configuration. However, it has not been used for ultrasonic guided wave phased array applications until now. In this paper, we propose a magnetostrictive transducer based phased array system consisting of a multi-channel function generator, power amplifiers and Lamb wave magnetostrictive transducers. To check the performance of the ultrasonic guided wave phased array, several Lamb wave focusing experiments were carried out in an aluminum plate. The results demonstrated the capability of the developed array to focus the Lamb waves at specific target points.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.157-159
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• 2007

For a vessel to safely navigate on the ocean, it is required to check the vessel position as frequently as possible. When a vessel navigates oil the ocean or entering/leaving a port, the target area such as islands, points and mountain peak, etc. are used. However, when such target are not available or when vessel navigates in night time, installed artificial navigation aid facilities help successful vessel navigation. Light Wave Aid helps to confirm a position to the navigator directly and quickly. So, the synchronous light to display the accurate signal has wide applications. However, lantern domestic industry is small, and most of the products show non-compatibility. Consequently, this paper presents the synchronous lighting using UTC of GPS, which maintains compatibility with different lanterns. Also, by replacing conventional electric bulb with LED lamp, simple and efficient lighting system is obtained.