• Title/Summary/Keyword: Misalignment

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A Study on the Fatigue Strength of a Welded Joint with Misalignment of a U-type Trough Rib in a Steel Deck Plate (강상판(鋼床版) U형(形) 트라프리브 단차용접(段差熔接)이음부(部)의 피로강도(疲勞强度)에 관(關)한 연구(硏究))

  • Lee, Dong Uk;Seo, Won Chan
    • Journal of Korean Society of Steel Construction
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    • v.8 no.3 s.28
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    • pp.13-20
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    • 1996
  • With the adoption of welded joints rather than bolted joints, we investigate the fatigue strength and the fatigue crack initiation of U-type trough rib and welded specimen with misalignment in a steel deck plate. The stress concentration factor of welded specimens with a misalignment is also verified by a finite element method. The main conclusions obtained from this study are as follows Experimental results of full-scaled U-type trough rib models have indicated that fatigue life depends on misalignments of welded joints in steel deck plate ; The more misalignments are, the less the fatigue life is. It has also shown that fatigue crack propagates from the welded root to the bead surface. We have also obtained the same results from both the fatigue test of welded specimens with a misalignment and the stress analysis of a finite element method.

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Failure Analysis of Optical Disk Drives Using the Vibration Signal Analysis (진동신호분석을 통한 광디스크 드라이브의 고장원인분석)

  • Park Youngpil;Shin Changho;Chung Jintai
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.7 s.238
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    • pp.1028-1034
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    • 2005
  • In this paper, the failure analysis of an optical disk drive is carried out and the limit ranges of the misalignment f3r the higher performance are presented. Since optical disks are removable from optical disk drive, the translational and angular misalignments, which causes read/write errors, always exist. Therefore, the limit ranges of the misalignment should be investigated. For this reason, the failure analysis by the vibration analysis is studied. The influences of the misalignment are tested by the aging test. And the limit ranges of the misalignment are proposed for the reliability of optical disk drives.

Design of a new omnidirectional image sensing system for assembly (OISSA) (조립을 위한 새로운 전방향 시각장치의 설계)

  • Kim, Wan-Su;Cho, Hyeong-Seok;Kim, Seong-Gwon
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.1
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    • pp.88-99
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    • 1998
  • In assembly, misalignment must be detected and compensated for during the mating period, regardless of the complexity of the cross-sectional shape. To this end, we propose a novel omnidirectional image sensing system for assembling parts with complicated shapes(OISSA) and its feasibility for detecting the misalignment between mating parts is shown by a series of simulations. This system encompasses a camera with an optical unit attached to the front of the camera. The optical unit consists of a pair of plane mirrors and a pair of conic mirrors. Utilizing the proposed sensing system, a 2$\pi$ coaxial image of the misalignment along the mating boundary interface between mating parts can be immediately obtained without experiencing self-occlusion.

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Optical Misalignment Cancellation via Online L1 Optimization (온라인 L1 최적화를 통한 탐색기 비정렬 효과 제거 기법)

  • Kim, Jong-Han;Han, Yudeog;Whang, Ick Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.7
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    • pp.1078-1082
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    • 2017
  • This paper presents an L1 optimization based filtering technique which effectively eliminates the optical misalignment effects encountered in the squint guidance mode with strapdown seekers. We formulated a series of L1 optimization problems in order to separate the bias and the gradient components from the measured data, and solved them via the alternating direction method of multipliers (ADMM) and sparse matrix decomposition techniques. The proposed technique was able to rapidly detect arbitrary discontinuities and gradient changes from the measured signals, and was shown to effectively cancel the undesirable effects coming from the seeker misalignment angles. The technique was implemented on embedded flight computers and the real-time operational performance was verified via the hardware-in-the-loop simulation (HILS) tests in parallel with the automatic target recognition algorithms and the intra-red synthetic target images.

Thermohydrodynamic Bubbly Lubrication Analysis of High-Speed Journal Bearing (공기 혼합오일에 대한 고속 저어널 베어링 열유체 윤활 해석)

  • 전상명
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.201-211
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    • 2001
  • The influence of aerated oil on high-speed journal bearing is examined by classical thermohydrodynamic lubrication theory coupled with analytical models for viscosity and density of aerated oil in fluid-film bearing. Convection to the walls, mixing with supply oil and re-circulating oil, and some degree of journal misalignment are considered. The considered Parameters for the study of bubbly lubrication are oil aeration level, air bubble size, shaft misalignment and shaft speed. The results show that deliberate oil aeration can more clearly bring on the increasing load capacity under high-speed operation of plain journal hearing than previous normal speed operation. And the load capacity may be increased more by oil aeration under the conditions of shaft misalignment and the increasing speed.

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Study of Radiographic Measurement on Cervical Misalignments in Scalenus Anticus Syndrome (사각근 증후군 환자의 경추 부정렬에 관한 방사선 사진 분석)

  • Keum, Dong-Ho;Kang, Ji-Hun
    • The Journal of Korean Medicine
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    • v.28 no.3 s.71
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    • pp.45-56
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    • 2007
  • Objectives : We investigated the possibility of cervical spine misalignment caused by scalenus anticus syndrome to find out how it affects cervical spine misalignments. Methods : 28 patients with scalenus anticus syndrome (sample group), along with 21 participants without neck pain (control group), who attended the Dept. of Oriental Rehabilitation Medicine, College of Oriental Medicine, Dong-guk University from the 20th of June to the 30th of November, 2006 were investigated. After researching misalignments through neutrality, flexion and extension lateral x-ray examination views, we measured the difference of each length of cervical spine misalignment. We analyzed the relationships among the neutrality lateral, flexion lateral and extension lateral positions. Results : We found with statistical significance that there were differences in length of cervical spine misalignments between the sample and control groups. Furthermore, we found that C3 and C4 vertebra bodies were shown in lateral neutrality position, only C3 vertebra body in flexion lateral position, and C2, C3, and C4 vertebra bodies in extension lateral position. Conclusions : It is considered that scalenus anticus syndrome could increase cervical spine misalignment which could be a factor in causing cervical spine disease.

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The Effects of Syllable Boundary Ambiguity on Spoken Word Recognition in Korean Continuous Speech

  • Kang, Jinwon;Kim, Sunmi;Nam, Kichun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.11
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    • pp.2800-2812
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    • 2012
  • The purpose of this study was to examine the syllable-word boundary misalignment cost on word segmentation in Korean continuous speech. Previous studies have demonstrated the important role of syllabification in speech segmentation. The current study investigated whether the resyllabification process affects word recognition in Korean continuous speech. In Experiment I, under the misalignment condition, participants were presented with stimuli in which a word-final consonant became the onset of the next syllable. (e.g., /k/ in belsak ingan becomes the onset of the first syllable of ingan 'human'). In the alignment condition, they heard stimuli in which a word-final vowel was also the final segment of the syllable (e.g., /eo/ in heulmeo ingan is the end of both the syllable and word). The results showed that word recognition was faster and more accurate in the alignment condition. Experiment II aimed to confirm that the results of Experiment I were attributable to the resyllabification process, by comparing only the target words from each condition. The results of Experiment II supported the findings of Experiment I. Therefore, based on the current study, we confirmed that Korean, a syllable-timed language, has a misalignment cost of resyllabification.