• Title/Summary/Keyword: Alignment

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A Study on the Optical Device Alignment Characteristics Improvement using Multi-Axis Ultra Precision Stage (극초정밀 다축 스테이지를 이용한 광소자 정렬 특성 향상에 관한 연구)

  • Jeong, Sang-Hwa;Cha, Kyoung-Rae;Kim, Gwang-Ho
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.12 s.177
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    • pp.175-183
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    • 2005
  • In recent years, as the demands of VBNS and VDSL increase, the development of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM elements increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this Paper, the optical alignment characteristic of multi-axis ultra precision stage is studied. The alignment algorithms are studied for applying to the ultra precision multi-axis stage. The alignment algorithm is comprised of field search and peak search algorithms. The contour of optical power signals can be obtained by field search and the precise coordinate can be found out by peak search. Three kinds of alignments, such as 1 ch. input vs. 1 ch. output optical stack, 1 ch. input vs. 8 ch. output PLC stacks, and ferrule vs. ferrule, are performed for investigating the alignment characteristics.

A Study on Alignment Measurement and Compensation for Spacecraft Sensors (위성 탑재 센서의 정렬 측정 및 보정에 관한 연구)

  • Lee Byoung-Gi;Kim Young-Youn;Yoon Yong-Sik
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.537-540
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    • 2005
  • The attitude control, sensors and camera installed on the spacecraft should be located according to the system alignment requirement. The alignment measurement requirement accuracy for the sensors should be below $\pm$0.1. Therefore, Alignment Measurement System which is combined theodolite, Rotating table and digital inclinometer etc., should be used. As the measurement accuracy is required very precise, the appropriate measurement procedure and alignment angle measurement, calculation and shimming work should is accomplished. Consequently, this paper is accomplished the works to align the measurement requirement accuracy throughout alignment measurement and shimming work of installed module and sensor

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Measurement Time-Delay Error Compensation for Transfer Alignment (전달정렬의 측정치 시간지연 오차보상 기법)

  • Lim, You-Chol;Song, Gi-Won;Lyou, Joon
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.11
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    • pp.953-957
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    • 2001
  • This paper is concerned with a transfer alignment method for the SDINS under ship motions. Major error sources of transfer alignment are data transfer time-delay, lever-arm velocity and ship body flexure. Specifically, to reduce alignment errors induced by measurement time-delay effects, the error compensation method through delay state augmentation is suggested. A linearized error model for the velocity and attitude matching transfer alignment system is first derived by linearizing the nonliner measurement equation with respect to its time delay and augmenting the delay state into the conventional linear state equations. And then it is shown via observability analysis and computer simulations that the delay state can be estimated and compensated during ship motions resulting in considerably less alignment errors.

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Implementation of an Initial Alignment Algorithm for a Stapdown Inertial Navigation system (스트랩다운 관성항법시스템의 초기정렬 알고리즘 구현)

  • Kim, Jong-Hyuk;Moon, Sung-Wook;Lee, See-Ho;Kim, Se-Hwan;Hwang, Dong-Hwan;Lee, Sang-Jeong;Ra, Sung-Woong
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.2
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    • pp.138-145
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    • 2000
  • In this paper an initial alignment algorithm for a strapdown inertial navigation system is implemented using a RISC CPU board. The algorithm computes roll pitch and yaw angles of the direction cosine matrix utilizing measured components of the specific force and earth rate when the navigation system is stationary. The coarse alignment algorithm is performed first and then the fine alignment algorithm containing a 3rd-order gyrocompass loop follows. The experimental set consists of an IMU a CPU board and a monitoring system Experimental results show that the implemented algorithm can be utilized in navigation systems.

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The Effect of Strategic Alignment on the Performance of Electronic Commerce (전략적 연동이 전자상거래의 성과에 미치는 영향)

  • Kang, Tae-Gyung;Hwang, Sang-Gyu
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.25
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    • pp.123-163
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    • 2005
  • The strategic alignment between internet marketing's strategic orientation and EC system's strategic orientation is an important concept in Electronic Commerce. This study measured internet marketing's strategic orientation, EC system's strategic orientation, strategic alignment, and strategic EC performance based on previous studies. Analysis of data gathered in mail survey of korea firms in KOSPI and KOSDAQ. The findings suggest that companies with high strategic alignment are better performing EC strategically, and internet marketing and EC system's strategic orientation are positive related to strategic alignment and performance of EC. This study supports that the level of the EC executive's participation in internet marketing planning influences strategic alignment of the EC plan with the internet marketing plan. Further, high levels of that alignment are associated with increased use of EC for strategic performance.

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Symmetric-viewing liquid crystal display with alternating alignment layers in an inverse-twisted-nematic configuration

  • Na, Jun-Hee;Li, Hongmei;Park, Seung-Chul;Lee, Sin-Doo
    • Journal of Information Display
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    • v.12 no.4
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    • pp.191-194
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    • 2011
  • A symmetric-viewing inverse-twisted-nematic (ITN) liquid crystal display (LCD) with alternating alignment layers was developed using a stamping-assisted rubbing (SAR) technique. A patterned layer of a fluorinated acrylate polymer was transferred onto the first rubbed vertical-alignment layer prepared on a substrate by stamping. The fluorinated acrylate polymer provided a protective layer covering the first rubbed alignment layer during the second rubbing process, which promoted the vertical alignment of the LC molecules. The LC cell in the ITN geometry with two orthogonally rubbed alignment layers showed symmetric-viewing characteristics with fourfold symmetry. The SAR technique was shown to be a mask-free alignment method of producing multidomains for symmetric-viewing LCDs.

Method for tool alignment error Compensation of Angle controlled Ultra-Precision machining (각도 제어 초정밀 가공기의 공구 위치 검출)

  • Park, Soon-Sub;Lee, Ki-Young;Kim, Hyoung-Mo;Lee, Jae-Seol
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.6 no.3
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    • pp.53-57
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    • 2007
  • This paper presents a geometrical error compensation of tool alignment for B axis controlled machine. In precision machining, tool alignment is crucial parameter for machined surface. To decrease tool alignment error, plus tilted tool from B axis center is touched to reference work piece and checked the deviation from original position. Same process is performed in minus tilt. Comparing these 2 touch positions, wheel alignment error in X axis and Z axis can be calculated on B axis center. Experimental results show that this compensation method is efficient to correct tool alignment.

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A Wafer Pre-Alignment System Using a High-Order Polynomial Transformation Based Camera Calibration (고차 다항식 변환 기반 카메라 캘리브레이션을 이용한 웨이퍼 Pre-Alignment 시스템)

  • Lee, Nam-Hee;Cho, Tai-Hoon
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.1
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    • pp.11-16
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    • 2010
  • Wafer Pre-Alignment is to find the center and the orientation of a wafer and to move the wafer to the desired position and orientation. In this paper, an area camera based pre-aligning method is presented that captures 8 wafer images regularly during 360 degrees rotation. From the images, wafer edge positions are extracted and used to estimate the wafer's center and orientation using least squares circle fitting. These data are utilized for the proper alignment of the wafer. For accurate alignments, camera calibration methods using high order polynomials are used for converting pixel coordinates into real-world coordinates. A complete pre-alignment system was constructed using mechanical and optical components and tested. Experimental results show that alignment of wafer center and orientation can be done with the standard deviation of 0.002 mm and 0.028 degree, respectively.

Comparison of the Body Alignment during Standing on Level and Wedge Board (평지와 쐐기 발판(wedge board) 위에 기립 시 신체정렬 비교)

  • Lee, Jeong-Weon
    • Physical Therapy Korea
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    • v.9 no.1
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    • pp.53-61
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    • 2002
  • The purpose of this study was to compare the body alignment during standing on level and wedge board. Twenty healthy college students (8 females, 12 males) were evaluated in this study. Diagnostic contourline potographic imaging system (Model JTC-1, Jodang Trading Co.) was used to measure body alignment. Sagittal and frontal plane images were used to analyze the body alignment. The result showed that the cervical and lumbar lordotic curve significantly decreased during standing on wedge board when compared with standing on level. On the other hand, thoracic kyphosis significantly increased during standing on wedge board. There was no significant difference in body alignment according to gender, weight, and height. Clinically, patients with low back pain and severe lordosis may be affected by heel wedge. Further study is needed to identify whether the standing on wedge board can change the body alignment in patients with low back pain and spinal deformity.

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The Effects of Schroth Exercise on Postural Alignment of Sagittal Plane in the Visually Impaired Students (슈로스 운동이 시각장애학생의 시상면 자세 정렬에 미치는 효과)

  • Kim, Gi-chul;Hwangbo, Pil-neo
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.24 no.1
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    • pp.1-6
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    • 2018
  • Background: This study was conducted to prove the effects of the Schroth exercise on sagittal postural alignment to the visually impaired students. Methods: The subjects were 8 students who attend the special school in Daegu and performed the Schroth exercise 3 times per week for 3 weeks. Craniovertebral angle and pelvic alignment were measured to compare the effects of the exercise. Results: Craniovertebral angle and pelvic alignment on sagittal plane showed significant differences (p<.05). Conclusions: Schroth exercise was effective to improve postural alignment of sagittal plane to the visually impaired students and these results will have a positive impact on future study of improvement of postural alignment on sagittal plane to the visually impaired students.