• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.97-101
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• 2001

Composite materials have been applied widely in interior panels of buildings and transport vehicles. Recently good fire performance and weight reduction are key issues in the fields. In the present study we investigated effects of processing parameters on the performance of honeycomb sandwich panels, especially peel strength of the panel and fire performance. The processing parameters considered were types of matrix resin, resin contents, panel cure conditions, and surface painting process conditions. The results showed that the higher resin content provides the better peel strength. Controled cure steps are also needed to obtain good pee] strength. Paint processing parameters including base putty thickness and paint drying conditions and paint thickness are important to obtain good paint adhesion and good fire performance.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.29-32
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• 2001

The objective of this work was to optimize processing parameters of hybrid thermoplastic composites in compression molding. The mechanical properties of the composites manufactured with various forming conditions were measured to characterize processing parameters. Polypropylene(PP) composites containing randomly oriented long carbon fiber and carbon black were used in this work. The composite materials contained 5%, 10%, 15%, and 20% carbon fiber and 5%, 10%, 15%, 20%, and 25% carbon black by weight. Compression molding was conducted at various mold temperatures. The temperature of the material in the mid-plain was monitored during the forming. Crystallinity was also measured by using XRD. The tensile modulus of the composites increase, with increasing the mold temperature. However, the impact strength of the composites decreases as mold temperature increases.

• Journal of Korea Multimedia Society
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• v.9 no.12
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• pp.1572-1579
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• 2006

An usual acoustic emission(AE) event has two widely characterized parameters in time domain, peak amplitude and event duration. But noise in AE measuring may disturb the signals with its parameters and aggrandize the signal incertitude. Experiment activity of detection of the nick inside of porcelain with AE was made and study on AE signal processing with statistic be presented in this paper in order to pick-up information expected from the signal with noise. Effort is concentrated on developing a novel arithmetic to improve extraction of the characteristic from stochastic signal and to enhance the voracity of detection. The main purpose discussed in this paper is to treat with signals on amplitudes with statistic mutuality and power density spectrum in frequency domain, and farther more to select samples for neural networks training by means of least-squares algorithm between real measuring signal and deterministic signals under laboratory condition. By seeking optimization with the algorithm, the parameters representing characteristic of the porcelain object are selected, while the stochastic interfere be weakened, then study for detection on neural networks is developed based on processing above.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1783-1788
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• 2003

In this study, the image processing program for deducing parameters of the elliptic shape of the partially overlapped liquid droplets was developed using the randomized Hough transform and the parameter decomposition. The procedure for the shape detection consists of three steps. For the first step, the candidate centers of ellipses are determined by the geometric property of the ellipse. Next, the rest parameters are estimated by the randomized Hough transform. In the final step for the post-processing, optimally approximated parameters of ellipses are determined. The developed program was applied to the simulated overlapped ellipses, real overlapped droplets, and real spray droplets. The shape detection was very excellent unless there existed inherent problems in original images. Moreover, this method can be used as an effective separating method for the overlapped small particles.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.118-122
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• 1997

This paper presents a 3d image processing which uses neural networks to combine a 2D vision camera and a laser slit beam. A laser slit beam from laser source is slitted by a set of cylindrical lenses and the line image of the slit beam on the object is used to estimate the object parameters. The neural networks allow to get the 3D image parameters such as the size, the position and the orientation form the line image without knowing the camera intrinsic parameters.

• Transactions of Materials Processing
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• v.20 no.8
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• pp.575-580
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• 2011

Direct laser melting(DLM) is promising as a joining method for producing parts for automobiles, aerospace, marine and medical applications. An advantageous characteristic of DLM is that it affects the parent metal very little. The mechanical properties of parts made by DLM are strongly affected by the porosity and surface roughness of the laser melted beads. This is a systematic study of the effects of the porosity and surface roughness of laser melted beads using various processing parameters, such as laser power, scan rate and overlapping ratio of the fill spacing. The specimens were fabricated with 316L and 304L austenitic stainless steel powder. Dense parts with low porosity were obtained at low laser scan speed, as it increased the aspect ratio of the parental material and the depth of penetration. The variations of surface roughness were examined at various processing parameters such as overlapping ratio and laser power.

• Korea-Australia Rheology Journal
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• v.18 no.4
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• pp.191-197
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• 2006

The measurement of the compressional rheological parameters for an aggregated particulate suspension is described. The parameters include the compressive yield stress and hindered settling function, describing the extent and rate of dewatering respectively. The variation of these parameters with shear rate and time of shear is also considered in the light of their sensitivity to low shear rates, with particular reference to the case of flocculated particulate suspensions. The latter is seen to be important in the future development of a comprehensive understanding of compressive rheology of aggregated particulate suspensions in industrial applications such as thickening, filtration and centrifugation.

• Journal of the Korean institute of surface engineering
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• v.36 no.1
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• pp.1-8
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• 2003

In general, the microstructure in thin films was known to evolve in similar manner according to the energy striking the condensing film at similar homologous temperature, Th for the materials of the same crystal structure. The fundamental factors affecting particle energy are a function of processing parameters such as working pressure, bias voltage, target/sputtering gas mass ratio, cathode shape, and substrate orientation. In this study, Al, Cu, Pt films of the same crystal structure of face centered cubic (FCC) have been prepared under various processing parameters. The influence of processing variables on the microstructures and residual stress states in the films has been studied.

• Macromolecular Research
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• v.10 no.6
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• pp.318-324
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• 2002

In this paper we have extensively studied what and how processing parameters for quasi-carbonization influence the breaking strength and modulus of resulting quasi-carbon fabrics that are prepared from stabilized PAN fabrics with a spun yarn texture. Seven processing parameters have been considered as follows: applied tension, final heat-treatment temperature, heating rate, heating step, holding time, cooling rate, and purging gas purity. The results indicate that optimal uses of applied tension, final heat-treatment temperature, heating rate, and heating step during quasi-carbonization process are primarily important to increase the tensile properties of quasi-carbon fabrics and holding time, cooling rate, and purging gas purity are less importantly contributed.

• Proceedings of the Korea Contents Association Conference
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• 2003.11a
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• pp.181-184
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• 2003

In the past, the image processing system is independently implemented and has a limit in its application to a degree of simple display. The scope of present image processing system is diversely extended in its application owing to the development of image processing It chips. In this paper, we implement the image processing system operated independently without PC by converting analogue image signals into digital signals. In the proposed image processing system, we extract the motion parameters from analogue image signals and generate the virtual movement to Simulator. Also we analysis the image control algorithm and operate Simulator by extracting motion parameters.