• 제목/요약/키워드: misalignment

검색결과 551건 처리시간 0.032초

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

  • 박영필;신창호;정진태
    • 대한기계학회논문집A
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    • 제29권7호
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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.

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

  • 김완수;조형석;김성권
    • 제어로봇시스템학회논문지
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    • 제4권1호
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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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온라인 L1 최적화를 통한 탐색기 비정렬 효과 제거 기법 (Optical Misalignment Cancellation via Online L1 Optimization)

  • 김종한;한유덕;황익호
    • 전기학회논문지
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    • 제66권7호
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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.

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

  • 전상명
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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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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사각근 증후군 환자의 경추 부정렬에 관한 방사선 사진 분석 (Study of Radiographic Measurement on Cervical Misalignments in Scalenus Anticus Syndrome)

  • 금동호;강지훈
    • 대한한의학회지
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    • 제28권3호통권71호
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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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    • 제6권11호
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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.

회전축 정렬불량을 가지는 유연회전디스크의 유한요소법을 이용한 시간응답해석 (Finite Element Analysis for Time Response of a Flexible Spinning Disk with Translating Misalignment)

  • 허진욱;정진태
    • 대한기계학회논문집A
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    • 제26권9호
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    • pp.1905-1913
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    • 2002
  • Using the finite element method, this study investigates the dynamic time responses of a flexible spinning disk of which axis of rotation is misaligned with the axis of symmetry. The misalignment between the axes of symmetry and rotation is one of the major vibration sources in optical disk drives such as CD-ROM, CD-R, CD-RW and DVD drives. Based upon the Kirchhoff plate theory and the von-Karman strain theory, three coupled equations of motion for the misaligned disk are obtained: two of the equations are for the in-plane motion while the other is for the out-of-plane motion. After transforming these equations into two weak forms for the in-plane and out-of-plane motions, the weak forms are discretized by using newly defined annular sector finite elements. Applying the generalized-$\alpha$ time integration method to the discretized equations, the time responses and the displacement distributions are computed and then the effects of the misalign ment on the responses and the distributions are analyzed. The computation results show that the misalignment has an influence on the magnitudes of the in-plane displacements and it results in the amplitude modulation or the beat phenomenon in the time responses of the out-of-plane displacement.