• Title/Summary/Keyword: Laser process

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Alignment Patterns and Position Measurement System for Precision Alignment of Roll-to-Roll Printing (롤투롤 인쇄전자공정에서 중첩정밀도 향상을 위한 정렬패턴과 위치 측정시스템)

  • Seo, Youngwon;Yim, Seongjin;Oh, Dongho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.12
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    • pp.1563-1568
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    • 2012
  • Printed electronics is a technology used for forming electronic circuits or devices, and it is used in the manufacture of many products such as RFID tags, solar cells, and flexible display panels with a much lower cost than in the case of semiconductor process technology. Web-guide-type printing such as roll-to-roll printing is a method used to produce printed electronic devices in a large volume. To commercialize such products, highly precise alignment between printed layers is required. In this study, a highly precise alignment system is proposed, and some experimental results are compared with those obtained using a laser surface vibrometer to illustrate the reliability of the proposed system. The robustness of the proposed system to web deformation is also considered experimentally.

Prevalence and Microbial Flora of Chicken Slaughtering and Processing Procedure

  • Seol, Kuk-Hwan;Han, Gi-Sung;Kim, Hyoun Wook;Chang, Oun-Ki;Oh, Mi-Hwa;Park, Beom-Young;Ham, Jun-Sang
    • Food Science of Animal Resources
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    • v.32 no.6
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    • pp.763-768
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    • 2012
  • This study has been performed to measure the prevalence and microbial flora on chicken slaughtering as well as the processing process from the months of October to November. Whole-chicken rinsing technique was used in order to analyze the incidence of microorganisms on chicken carcass at the stage before chilling (after evisceration), after chilling and after cutting. The swab technique was used on processing the processed samples, such as working plates and cutting knives. Brine and cooling water from four cooling tubs were taken from each processing processes and were used as samples. Furthermore, the matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) for whole cell fingerprinting in combination with a dedicated bioinformatic software tool was used to identify the isolated microorganisms. Of the tested samples and processes, brine ($4.50{\pm}0.64$ Log CFU/mL) and chicken carcass before chilling ($4.15{\pm}0.46$ Log CFU/mL) showed the highest population of microorganisms; the predominant microbial flora of them were Moellerella wisconsensis (54.84%), a member of the Enterobacteriaceae family, and Escherichia coli (60.36%), respectively. However, the predominant microbial flora of cut carcass was changed to Staphylococcus aureus (27.32%), which is a kind of pathogenic microorganism that can cause a food-borne illness. Therefore, the slaughtering and processing procedure of chicken are needed to be controlled more hygienically.

Comparison of Physical Properties of Hanjis Made by Different Sheet Forming Processes (초지법에 따른 한지의 물성비교)

  • 최태호;조남석;최인호;정택상
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.33 no.4
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    • pp.21-27
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    • 2001
  • Korean traditional paper (Hanji) making technology has adopted two kinds of sheet forming processes, which called "Oebal-choji": and "Ssangbal-choji". The sheet forming process of Oebal-choji is an original method developed in Korea. At first, paper stock is dipped onto the mold and flow away in the forward direction. Then, paper stock is scooped again and rhythmically rocked from side to side, this work is repeated several times. Through this operation the fibers intertwine and paper layers are formed. Ssangbal-choji is almost same as the Nagashizuki, which used in Japan. In this method, paper stock is scooped onto the mold and rhythmically rocked backwards and forwards several times, the water drains slowly through the bamboo screen and then sheet is formed. Tamezuki method is used in Japan and China. This is a method in which the mold is dipped into the paper stock once and left to drain. In the Ssangbal-choji and Nagashizuki methods, the most of excess solution is cast out while in the Tamezuki all of it is allowed to drain through the mold. This study was carried out to investigate the physical properties of the Hanjis that were made by Oebal-choji, Ssangbal-choji, Nagashizuki, and Tamezuki sheet forming processes. The results were follows; Physical properties of the Oebal-choji Hanji were better than those of Ssangbal-choji, Nagashizuki, and Tamezuki. Oebal-choji Hanji made little difference of paper strength between MD and CD, but Ssangbal-chjo and Nagashizuki Hanjis made wide difference. And there are no difference of paper strength between MD and CD on the Tamezuki Hanji. On the confocal laser scanning microscopy (CLSM) observation of the Hanjis, Oebal-choji made well crossed fiber orientation than those of other forming processes.r forming processes.

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Non-linear optical properties of PECVD nanocrystal-Si nanosecond excitation (PECVD로 제조된 나노결정실리콘 비선형 광학적특성)

  • Yang, Hyeon-Hun;Kim, Han-Wool;Kim, Joo Hoe;Kim, Chul Joong;Lee, Chang Gwon
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.60.2-60.2
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    • 2011
  • A study of the non-linear optical properties of nanocrystal-Si embedded in SiO2 has been performed by using the z-scan method in the nanosecond and femtosecond ranges. Substoichiometric SiOx films were grown by plasma-enhanced chemical-vapor deposition(PECVD) on silica substrates for Si excesses up to 24 at/%. An annealing at $1250^{\circ}C$ for 1 hour was performed in order to precipitate nanocrystal-Si, as shown by EFTEM images. Z-scan results have shown that, by using 5-ns pulses, the non-linear process is ruled by thermal effects and only a negative contribution can be observed in the non-linear refractive index, with typical values around $-10-10cm^2/W$. On the other hand, femtosecond excitation has revealed a pure electronic contribution to the nonlinear refractive index, obtaining values in the order of 10-12 cm2/W. Simulations of heat propagation have shown that the onset of the temperature rise is delayed more than half pulse-width respect to the starting edge of the excitation. A maximum temperature increase of ${\Delta}T=123.1^{\circ}C$ has been found after 3.5ns of the laser pulse maximum. In order to minimize the thermal contribution to the z-scan transmittance and extract the electronic part, the sample response has been analyzed during the first few nanoseconds. By this method we found a reduction of 20% in the thermal effects. So that, shorter pulses have to be used obtain just pure electronic nonlinearities.

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Fabrication of a Nano-Wire Grid Polarizer for Brightness Enhancement in TFT-LCD Display (TFT-LCD용 휘도 성능을 향상시키는 나노 와이어 그리드 편광 필름의 제작)

  • Huh, Jong-Wook;Nam, Su-Yong
    • Journal of the Korean Graphic Arts Communication Society
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    • v.29 no.3
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    • pp.105-124
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    • 2011
  • TFT-LCD consists of LCD panel on the top, circuit unit on the side and BLU on the bottom. The recent development issues of BLU-dependent TFT-LCD have been power consumption minimization, slimmerization and size maximization. As a result of this trend, LED is adopted as BLU instead of CCFL to increase brightness and to reduce thickness. In liquid crystal displays, the light efficiency is below 10% due to the loss of light in the path from a light source to an LCD panel and presence of absorptive polarizer. This low efficiency results in low brightness and high power consumption. One way to circumvent this situation is to use a reflective polarizer between backlight units and LCD panels. Since a nano-wire grid polarizer has been known as a reflective polarizer, an idea was proposed that it can be used for the enhancement of the brightness of LCD. The use of reflective polarizing film is increasing as edge type LED TV and 3D TV markets are growing. This study has been carried out to fabrication of the nano-wire grid polarizer(NWGP) and investigated the brightness enhancement of LCD through polarization recycling by placing a NWGP between an c and a backlight unit. NWGPs with a pitch of 200nm were fabricated using laser interference lithography and aluminum sputtering and wet etching. And The NWGP fabrication process was using by the UV imprinting and was applied to plastic PET film. In this case, the brightness of an LCD with NWGPs was 1.21 times higher than that without NWGPs due to polarization recycling.

The Optimization of Offset Printing Process for High Quality Color Reproduction (II) - Platemaking and Presswork - (고품질 색재현을 위한 오프셋 인쇄공정의 최적화에 관한 연구(II) - 제판과 인쇄공정을 중심으로 -)

  • Kim, Sung-Su;Kang, Sang-Hoon
    • Journal of the Korean Graphic Arts Communication Society
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    • v.25 no.2
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    • pp.69-84
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    • 2007
  • Producing printing plate is essential progress to do offset printing. In this Film-less period, the more PS plate becomes extinct, the more the age of the Plate-Making of Exposure declines the place to stand. To do offset printing, the CTP (Computer to Plate) is taking a place of PS plate that covers speed, quality and economical problems. The biggest advantage of using CTP is that laser directly goes to the plate, thus there are no dust from the Plate-Making of Exposure. It is also theoretically able to print $200lpi{\sim}300lpi$ as well as print 1751pi, because it has over 2400dpi resolution. The high quality printing could be available inside of the country, if printing machine keeps the optimum condition in offset printing. The CTP has many advantages, however there is a difficulty for the operators to preserve the equipment. The actual circumstance is that they cannot make a decision about how many dots need to be generated, and also it is necessary to know how to establish the setup at RIP on CTP to make the optimum condition output. If offset printing machine keeps the optimum condition, it would be able to print up to high quality printing however it is hard to comment what is the optimum condition for the printing machine. Anyone could say easy subjectively that machine is in the optimum condition, however it is objectively hard to estimate by number. In this research GATF / Plate Test target used to analyze the image and to make numerical value of the optimum condition of the CTP. It also used GATF / The sheep fed test printing 5.0 to know the density of the color representation, dot gain and gray balance for the optimum condition of the print machine. The purpose of this research is to represent the ISO 12647-2 which is the international standard with domestic printing equipments.

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Sensitivity Optimization of MEMS Gyroscope for Magnet-gyro Guidance System (자기-자이로 유도 장치를 위한 MEMS형 자이로의 민감도 최적화)

  • Lee, Inseong;Kim, Jaeyong;Jung, Eunkook;Jung, Kyunghoon;Kim, Jungmin;Kim, Sungshin
    • The Journal of Korea Robotics Society
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    • v.8 no.1
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    • pp.29-36
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    • 2013
  • This paper presents a sensitivity optimization of a MEMS (microelectromechanical systems) gyroscope for a magnet-gyro system. The magnet-gyro system, which is a guidance system for a AGV (automatic or automated guided vehicle), uses a magnet positioning system and a yaw gyroscope. The magnet positioning system measures magnetism of a cylindrical magnet embedded on the floor, and AGV is guided by the motion direction angle calculated with the measured magnetism. If the magnet positioning system does not measure the magnetism, the AGV is guided by using angular velocity measured with the gyroscope. The gyroscope used for the magnet-gyro system is usually MEMS type. Because the MEMS gyroscope is made from the process technology in semiconductor device fabrication, it has small size, low-power and low price. However, the MEMS gyroscope has drift phenomenon caused by noise and calculation error. Precision ADC (analog to digital converter) and accurate sensitivity are needed to minimize the drift phenomenon. Therefore, this paper proposes the method of the sensitivity optimization of the MEMS gyroscope using DEAS (dynamic encoding algorithm for searches). For experiment, we used the AGV mounted with a laser navigation system which is able to measure accurate position of the AGV and compared result by the sensitivity value calculated by the proposed method with result by the sensitivity in specification of the MEMS gyroscope. In experimental results, we verified that the sensitivity value through the proposed method can calculate more accurate motion direction angle of the AGV.

The Effect of Botulinum Toxin Type A for the Vocal Fold Granuloma (Botulinum Toxin Type A (BOTOX$^{\circledR}$)를 이용한 성대 육아종의 치료효과)

  • 김정홍;김한수;남지인;장정현;김지훈;최홍식
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.14 no.1
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    • pp.40-46
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    • 2003
  • Background and Objectives : The vocal fold granuloma has been associated with vocal abuse, gastroesophageal reflux, endotracheal intubation and habitual throat clearing etc.. Granuloma is benign growth of hypertrophic granulation tissue. It is usually located on the posterior third of vocal fold, in one or both vocal process of the arytenoid cartilage In spite of the voice therapy, steroid therapy, anti-reflex therapy and surgical procedure. The distinct advantage and uniform success rate of each methods have not been generally shown. Authors report that localized injection of botulinum toxin type A (BOTOX$^{\circledR}$) is the promising method both as an initial treatment and as an alternative treatment in patients who do not respond to standard therapy or who are poor surgical candidates. Materials and Method : We carried out a retrospective study of 9 patients with the diagnosis of vocal fold granuloma on the videostroboscopic examination from Jan 2000 to Mar 2003. The botulinum toxin type A was injected into one or both thyroarytenoid muscle or lateral cricoarytenoid muscle under the electromyography. The average dosage ranges from 6U to 8U per injection. Results : Unilateral vocal fold granuloma in 7 patients had been resolved completely within 2-3 months after first injection : 5 patients received th\ulcorner GER medical therapy in addition to the Botulinum toxin injections, 2 patients was resolved completely who had shown recurrence after $CO_2$ laser vaporization. 2 patients who had shown recurrence after $1^st$ injection were also completely resolved within 6 months after further injections. Conclusion : We expect that localized injection of Botulinum toxin type A can provide an alternative treatment for the refractory cases to the traditional forms of therapy and avoid the recurrence in conjunction with proper medical and voice therapy against GER and vocal abuse.

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Papers : Simultaneous Monitoring of Strain and Temperature During and After Cure of Unsymmetric Cross - ply Composite Laminate Using Fiber Optic Sensors (논문 : 비대칭 직교적층 복합재료 적층판의 성형시 및 성형후 광섬유 센서를 이용한 변형률 및 온도의 동시 모니터링)

  • Gang,Hyeon-Gyu;Gang,Dong-Hun;Hong,Chang-Seon;Kim,Cheon-Gon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.30 no.1
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    • pp.49-55
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    • 2002
  • In this paper, we present the simulation monitoring of strain and temperature during and after the cure of unsymmetric composite laminate using fiber optic sensors. Fiber Bragg grating/extrinsic Fabry-Perot interferometric (FBG/EFPI) hybrid sensors are used to measure those measurands. The characteristic matrix of the sensor is analytically derived and measurements can be done without sensor calibration. A wavelength-swept fiber laser is utilised as a lighr source. Two FBG/EFPI sensors are embedded in a graphite/epoxy unsymmetric cross-ply composite laminate in different directions and different locations. We perform a real time monitoring of fabrication strains and temperatures at two points of the composite laminate during cure process in an autoclave. Also, the thermal strains and temperatures of the fabricated laminate are measured in a thermal chamber. Through these experiments, we can provide a basis for the efficient smart processing of composite and know the thermal behavior of unsymmetric cross-ply composite laminate.

The Planning and Design of Urban Streams Based on 3D Terrain Modelling (3차원 지형모델링에 기반한 도시하천의 계획 및 설계)

  • Park, Eun Gwan;You, Ji Ho;Lee, Hyun Jik
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.2
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    • pp.59-67
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    • 2015
  • When planning for streams, adequate and definite flood control should be in the primary consideration of the planner; likewise, flood control is the basic prerequisite for the recent river restoration taking place nationwide. Planning 'safe' streams and rivers that are predictable and controllable begins from accurate survey data. In this research, we will create streams in 3D terrain models and apply them through hydraulic analysis and restoration using smart geospatial information. This process allows the extraction of more accurate data regarding streams and rivers, which makes possible precise hydraulic analysis that is superior in details to the conventional methods. The study also proposes optimal vertical section interval for efficient data processing on hydraulic analysis, applicable when LiDAR data is utilized on hydraulic analysis of urban streams. The study proposes 3D design plan and various applications for spatially planning and restoring rivers and streams.