• Title/Summary/Keyword: Rotation Operation

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Development of Inspection Methods for Bearing Faults with a Rapid Change of Rotation Speed and Optimization of Pass/Fail Criteria (회전 속도가 급격히 변화하는 베어링의 양부 검사 기법 개발 및 검사 기준 최적화)

  • Yang, Won Seok;Lee, Won Pyo;Lee, Jong Woo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.25 no.3
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    • pp.273-286
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    • 2017
  • We develop an inspection method for bearing faults with a rapid change in the rotation speed and present indexes for the pass/fail inspection. At the end of line, impulse noises generated by the operation of machines and conveyors may distort the inspection results. In this paper, we present robust inspection indexes for bearing faults under impulse noises, by taking into account fault signals having pulse train. Using logistic regression, we optimize the pass/fail criterion for each index and evaluate the performance of the inspection indexes based on the total error rate.

Variation of Camera Constant and Image Rotation in HU-125C Electron Microscope (HU-125C 전자현미경에 있어서 카메라 상수의 변화 및 상의 회전에 대한 조사)

  • Choi, Ju;Ye, Gil-Chon
    • Applied Microscopy
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    • v.4 no.1
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    • pp.1-4
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    • 1974
  • Variations of camera constant due to the change of the lens current were examined for Hitachi HU-125C electron microscope. It was shown that the variation in specimen height had a marked effect on the change of camera constant. Also the rotation of the image from the diffraction pattern was determined by using a test crystal. Suggestions were given for improving practical operation of electron microscope in the work of thin foils.

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A Study on Modeling the Screw for Permanent Fixing and the Simulation of Fixing force (영구 체결용 나사 모델링과 체결력 시뮬레이션에 관한 연구)

  • Lee, S.S.;Prak, J.H.;Kim, M.J.;Park, J.B.;Jeon, E.C.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.827-833
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    • 2001
  • This study is an introduction of ADS in which we have written out programs which can design three-dimensional machine parts and reduce the required time for design them comparing with other CADs. Among the machine parts, screws are commonly used in joining one part to another because of easy handing but welding and rivet are used to join permanently them even thought hard operation. Consequently, we have developed the screw for permanent fixing using stairs type screw threads, which is considered as the main machine parts in joining. For that, we designed permanent fastened screws according to the different rotation angle using VisualLISP and transferred it to ANSYS, structural solution program, to find out allowance load, maximum equivalent stress and where it occur.

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A Study on the Development of the Screw for Permanent Fixing using Stairs Type Screw Threads (계단형 나사산을 이용한 영구 체결용 나사개발에 관한 연구)

  • 김민주;김세민;이승수;김순경;전언찬
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.1003-1007
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    • 1997
  • This study is na introduction of ADS in which we have written out programs which can design three-dimensional machine parts and reduce the required time for design them comparing with other CADs. Among the machine parts, screws are commonly used in joining one part to another because of easy handling but welding and rivet are used to join permanently them even thought hard operation. Consequently, w have developed the screw for permanent fixing using stairs type screw threads, which is considered as the main machine parts in joining. For that, we designed permanent fastened screws according to the different rotation angle using VisualLISP and transferred it to ANSYS, structural solution program, to find out allowance load, maximum equivalent stress and where it occur.

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INVESTIGATION OF THE PILE MOVEMENT DUE TO TUNNELLING BY MODEL TEST AND NUMERICAL ANALYSIS

  • Lee, Yong-Joo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09c
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    • pp.104-110
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    • 2010
  • In this study, a series of two-dimensional model test and numerical analysis was carried out to investigate the pile movement due to tunnelling in soft ground. The model test consists of 21 cases according to locations of the pile tip over the centre position of model tunnel. To identify both the pile and ground movements a close-range photogrammetric technique was adopted in the model test. The results from the model test were compared to the two-dimensional finite element analysis using the CRISP program. It was found that the rotation point on the pile was significantly affected by factors such as the offset distance from the model tunnel and the volume loss that occurred during the tunnelling operation.

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An Analysis of the Noise Feature of a Static Frequency Converter (SFC) according to the Operation of a Gas Turbine (가스터빈 기동에 따른 정지형 주파수 변환장치(SFC:Static Frequency Converter)의 노이즈 특성 분석)

  • Jeong, Tae-Hoon;Choi, Sung-Wook;Kim, Hyeun-Soo
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.2025-2026
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    • 2008
  • This study aims to analyze the features of malfunction of an SFC that helps maintain the frequency of static rotation during the operation of a gas turbine in power plants where power generators and controllers have such a complicated structure as a nerve system, by using electric interference with peripheral devices and maintaining acquired data efficiently. Also, in order to track the possibility of malfunction by various surges and noises which may occur in the process of inserting an SFC during the operation of a gas turbine and to prepare protective measures for the possibility, the study intends to offer data for developing a surge protector suited to the features of a section that is supposed to incur the possibility of malfunction.

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Clinical and Radiological Outcome after Surgical Treatment in Displaced Clavicular Midshaft Fracture

  • Gwak, Heui-Chul;Kim, Jung-Han
    • Clinics in Shoulder and Elbow
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    • v.19 no.2
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    • pp.73-77
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    • 2016
  • Background: The first purpose of this study is to compare the clinical and radiological outcomes of surgical treatment for displaced midshaft clavicle fracture (Robinson type 2B1 vs. 2B2) with 3.5-mm low profile clavicular locking compression plate. The second purpose is to evaluate the difference of the results depending on the presence of accompanying injuries. Methods: Forty-nine patients who underwent an operation for the fractures were reviewed retrospectively. Fracture patterns were classified according to group 2B1 and 2B2 using Robinson's classification. For radiological outcome, time to union after operation was evaluated and for clinical outcome, American Shoulder and Elbow Society (ASES) score, University of California in Los Angeles (UCLA) score, visual analogue scale (VAS), and range of motion (ROM) were evaluated from preoperative period to last follow-up period. Results: The mean time for union was not significantly different in the 2B1 group and 2B2 group (p=0.062). No statistically significant difference in ASES score, UCLA score, and VAS was observed between 2B1 and 2B2 (p=0.619, p=0.896, p=0.856, respectively). In ROM, significant higher mean forward flexion and abduction was observed in 2B2 (p=0.025, p=0.017, respectively) and there was no difference in external rotation and external rotation at shoulder $90^{\circ}$ abduction position (p=0.130, p=0.180, respectively). There was no significant difference in clinical outcomes according to the accompanying injuries. Conclusions: There was no difference in clinical and radiological outcome between Robinson 2B1 and 2B2 type fracture after the operation. Accompanying injuries may not affect the clinical result of displaced midshaft clavicle fractures.

Efficacy of the Subclavian Portal Approach in Arthroscopic Repair of Isolated Subscapularis Tendon Tear

  • Chae, Seung Bum;Choi, Chang Hyuk;Jung, Suk-Han
    • Clinics in Shoulder and Elbow
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    • v.17 no.1
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    • pp.18-24
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    • 2014
  • Background: To evaluate the efficacy of the subclavian portal approach for the arthroscopic repair of isolated subscapularis tendon tear. Methods: We used the subclavian portal to carry out arthroscopic repair of the isolated subscapularis tendon tear. The surgery was carried out in 18 cases (average age of 53) from May 2006 to December 2009 with a mean follow-up period of 35 months. Of these cases, 13 patients had the tear in their dominant arms, 16 were male, and 12 were from traumatic ruptures with on average 7.6 months of symptom period to operation. Additional surgery, acromioplasty and subacromial debridement, were carried out on 4 cases each during the subscapularis repair. The integrity of cuff status was assessed by ultrasonographic examination at 6 months and at 1 year after operation. Results: The initial average range of motion in forward flexion, external rotation, and internal rotation were $160^{\circ}$, $50^{\circ}$ and L4, respectively. At the 1 year follow-up period, these improved to $160^{\circ}$, $52^{\circ}$ and T12, respectively. The initial average functional scores were assessed by KSS, ASES, UCLA, and Constant scoring systems, which were 67, 60, 26, and 65, respectively. These scores improved progressively with time. At 3 months after operation, the scores were 74, 67, 27, and 74; at 6 months, 83, 77, 31, and 75; at 1 year, 88, 86, 32, and 79; and at the final follow-up of 35 months, 84, 92, 34, and 84. Conclusions: In the repair of isolated subscapularis tendon tear, the subclavian portal approach provided a good angle for anchor insertion and sufficient space to manage the upper portion of the tendon tear. In turn, these provisions resulted in satisfactory clinical results.

A COMPARATIVE STUDY ON CRONIN TRIANGULAR FLAP AND ROTATION-ADVANCEMENT REPAIR IN UNILATERAL COMPLETE CLEFT LIP (편측성 완전구순열에서 Cronin 삼각피판법과 회전신전법에 의한 수복의 비교)

  • Ryu, Sun-Youl;Yun, Cheon-Ju
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.23 no.5
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    • pp.415-421
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    • 2001
  • The present study was carried out to compare the postoperative results of Cronin triangular flap and Millard rotation-advancement repair techniques in repairing the unilateral complete cleft lip. Thirteen patients with unilateral complete cleft lip underwent 6 Cronin triangular flap and 7 Millard rotation-advancement repairs at the Department of Oral and Maxillofacial Surgery of Chonnam University Hospital over a period of 6 years (January 1994 to December 1999). The surgical results following the operation were assessed on the basis of scoring, vertical lip length and scar hypertrophy. The mean score was better in Cronin triangular flap group($74.77{\pm}0.86$) than in Millard rotation-advancement group($66.50{\pm}1.14$) for both lip and nose segments. Scar hypertrophy developed in the Millard rotation-advancement repair group with 28.6% incidence but not in the Cronin triangular flap group. No significant difference was found in the ratio of lip length between Millard rotation-advancement repair and Cronin triangular flap groups($0.73{\pm}0.10$ and $0.80{\pm}0.96$). These results suggest that Cronin triangular flap shows better results than Millard rotation-advancement repair in repairing the unilateral complete cleft lip.

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Simultaneous Repair of Unilateral Cleft Lip and Hard Palate with Vomer Flap : a Case Report (편측성 구순구개열 환자에 있어 구순성형술과 동반한 서골피판법 치험례)

  • Park, Hyong-Wook;Song, In-Seok;Kim, Eu-Gene;Kim, Soo-Ho;Cheon, Kang-Yong;Seo, Byoung-Moo
    • Korean Journal of Cleft Lip And Palate
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    • v.15 no.2
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    • pp.61-68
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    • 2012
  • Cleft lip and palate is the most common congenital facial malformation and has a significant developmental, physical, and psychological impact on those with the deformity and their families. When treating the patients with unilateral cleft lip, many surgeons adopt the rotation advancement flap method originally developed by Millard, or the triangular flap technique developed by Tennison, Randall or the modifications of these techniques. Among these, Millard's rotation advancement flap method has its advantage in designing the flap using the patient's anatomic landmarks. For performing this rotation advancement technique, skillful operation is needed to obtain esthetically satisfactory results. Vomer flap sometimes is used to repair anterior hard palate in complete cleft lip and palate patients. Vomerine tissue is readily available in the vicinity of the palatal defect and elevation of the vomerine flap is relatively simple procedure. In this article, we will introduce the comprehensive vomer flap technique conjunction with primary lip closure and review the comparative studies of the outcome of simultaneous repair of cleft lip and cleft hard palate with Millard's rotation advancement method and vomer flap.

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