• The Journal of the Acoustical Society of Korea
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• v.5 no.1
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• pp.24-34
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• 1986

Recently, as the noise problems of mechancial structures have been more serious, much studies are being carried out on the identification of noise sources and the reduction of noise level. In this paper, as the application of frequency analysis, the multi-dimensional spectral analysis method is applied to daisy wheel printer to identify the noise sources, and the relationship between sound pressure and vibration of printer is found in narrow and overall frequency range. The results of this study are compared with those of frequency response function method, thus, the applicability of multidimensional spectral analysis method is verified. It can be found, in a overall frequency range, that the vibration of platen have the worst effect on noise level, and the noise level reduction of 6dB, 7.9dB is obtained by changing the platen thickness to 2mm, 4mm, respectively.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1947-1950
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• 2008

Printing technology is a very useful method in the several process of industrial fabrication due to noncontact and fast pattern generation. To make micro pattern, we investigate the electrostatic induced inkjet printer head for micro droplet generation and drop-on-demand jetting. In order to achieve the drop-on-demand micro droplet ejection by the electrostatic induced inkjet printer head, the pulsed DC voltage is supplied. In order to find optimal pulse conditions, we tested jetting performance for various bias and pulse voltages for drop-on-demand ejection. In this result, we have successful drop-on-demand operation and micro patterning. Therefore, our novel electrostatic induced inkjet head printing system will be applied industrial area comparing conventional printing technology.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.295-295
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• 2000

In this paper, the measurement algorithm of PCB alignment error is developed using image processing. The X-Y-$\theta$ table correcting PCB alignment error is driven by drive module based on microprocessor according to calculation results obtained through image processing procedure. In order to recognize the X-Y-$\theta$ position errors, two fiducial points are marked on PCB and two cameras of ultraviolet rays types are used for detection of the points to capture exactly fiducial points under disturbance of illumination change. Through application for a practical screen printer, the precision control using the developed position control system can be realized about 2.5${\mu}{\textrm}{m}$ in table moving range and 8${\mu}{\textrm}{m}$ in camera processing precision.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.5-6
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• 2016

Due to the construction of high-rise and long axis etc, UHPC(Ultra High Performance Concrete) has attracted attention as a material that will replace the existing concrete. In order to improve the structural performance of each member joints, after demolding the concrete, method for surface treatment of the contact surface or by modifying the mold to create a shear key will be applied. In this study, to improve the conventional shear key manufacturing process, utilizing a 3d printer to produce a shear key plate. 3D printers have advantage it is inexpensively manufactured as compared with other production methods. Therefore, this study utilizes a 3D printer, we propose the shear key-shaped mold and plate shear key production measures.

• Journal of the Korean Graphic Arts Communication Society
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• v.19 no.2
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• pp.58-67
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• 2001

Gamut mapping is a technique that acts on cross-media color reproduction to transform a color between devices for the purpose of enhancing the appearance or preserving the appearance of an image. Gamut mapping essentially produces color conversion error which depends the gamut mapping method, source and destination devices, and sample points for gamut modeling. For color space conversion between monitor colors and printer colors, empirical representation using sample measurements is currently widely utilized. Color samples are uniformly selected in the device space such as CMY or RGB, represented as color patches, and then measured. However, in the case of printer, these color samples are not evenly distributed inside the printer gamut and the color conversion error is increased. Accordingly, this paper introduces a equally distributed color sampling method in CIELAB space, a device- independent color space, to reduce color conversion error, and the performance is analyzed via color space conversion experiments using tetrahedral interpolation.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.466-468
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• 2005

Recently, the demand for the development of high quality and high speed laser printer and efficient power utilizations are required. Among complicate electro-mechanic devices in laser printer, the toner fusing unit consumes above 90[%] of all electrical energy needed for printing devices. Therefore, the development of more effective energy-saving toner fusing process becomes a significant task of much great demand. Generally, there are several way to implement fusing unit, among them this paper present a new hybrid induction heating method. The proposed induction heating method enables to increase coupling coefficient between heating coil and heat roller also to Increase total energy transfer efficiency. Therefore the proposed IH inverter system provide very fast W.U.T.(Warm UP Time), also high efficiency. Through experimental result, the proposed control system is verified.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2231-2235
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• 2008

Thermal performance of fusing system in laser printer is determined by FPOT(First print out time) required and toner fusing quality. FPOT is influenced by the thermal resistance of fusing system between heat source and nip region. Also FPOT is depended by the heat source power and toner fusing temperature. The fusing quality of toner is decided by the temperature, pressure and duration time in nip region. In this study, I have performed thermal analysis for the toner fusing system. Computational simulation has been used to understand the effect of heat source power and printing speed etc. on the temperature distribution of the fusing system. Also in order to predict fusing quality, numerical simulation of the process that paper is continuously supplied to the nip regions were performed. In comparison with the experimental results of the fusing quality vs transferred calory to the toner layer, I could evaluate various fusing condition parameters effected on the thermal performance.

• Korean Journal of Computational Design and Engineering
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• v.22 no.2
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• pp.215-221
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• 2017

This paper describes a method of precise estimation for printing time and material consumption which are directly related to the 3D printing cost. Printing process and head motion of 3D printers using digital printing head, which is analyzed by its digitized steps, is rapidly simulated without slicing to calculate estimated printing results. Using this method, printing time and material usage of 3D printer were estimated quickly and precisely and compared to the real printing result. Applying compensation using the printing parameters, transferred from the 3D printer to the printing estimation system, even more accurate estimation is achieved. This method is used in the 3D Sprint software.

• International Journal of Safety
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• v.8 no.2
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• pp.5-8
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• 2009

Fusing process of laser printer is the step to fuse toner on the paper and it has a great effect on fast printing speed, decrease in waiting time and improvement of printing quality. In order to improve the quality of fusing, a study on the fusion region is required. Recently, various researches are progressing in this field. In this study, the research about the temperature distribution of fusing region is performed through numerical analysis because fusing region is one of the important factors influencing fusing quality. According to results, it is ascertained that the temperature of fusing region is relative to velocity of the paper under print and has a regular distribution to width direction of the paper.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.111-116
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• 2018

Recently, shape manufacturing method has been changed to a 3D printer. Since lamination type manufacturing method is the basis for forming a three-dimensional shape by repeated lamination, the horizontal accuracy of the lamination layer is very important. In the current paper, we have proposed a new leveling system to be installed in a large 3D printer. The light source was reflected from the water surface contained in the measuring device, and the inclination of the measuring device was measured from the light that entered into four regions of a quarter photodetector. The electrical signals generated differently according to the position of the beam spot incident on the quarter photodetector was acquired and compensated to be horizontal by using a motor mounted at the corner. Compared to a digital leveler, the newly developed leveling system gave errors of only 2 to 3%. This new device can be applied to various fields including the 3D printer in future.