• Title/Summary/Keyword: Locking System

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Internal Fixation with a Locking T-Plate for Proximal Humeral Fractures in Patients Aged 65 Years and Older

  • Yum, Jae-Kwang;Seong, Min-Kyu;Hong, Chi-Woon
    • Clinics in Shoulder and Elbow
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    • v.20 no.4
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    • pp.217-221
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    • 2017
  • Background: The purpose of this study was to evaluate the clinical and radiographic outcomes of internal fixation with locking T-plates for osteoporotic fractures of the proximal humerus in patients aged 65 years and older. Methods: From January 2007 through to December 2015, we recruited 47 patients aged 65 years and older with osteoporotic fractures of the proximal humerus. All fractures had been treated using open reduction and internal fixation with a locking T-plate. We classified the fractures in accordance to the Neer classification system; At the final follow-up, the indicators of clinical outcome-the range of motion of the shoulder (flexion, internal rotation, and external rotation) and the presence of postoperative complications-and the indicators of radiographic outcome-the time-to-union and the neck-shaft angle of the proximal humerus-were evaluated. The Paavolainen method was used to grade the level of radiological outcome in the patients. Results: The mean flexion was $155.0^{\circ}$ (range, $90^{\circ}-180^{\circ}$), the mean internal rotation was T8 (range, T6-L2), and the mean external rotation was $66.8^{\circ}$ (range, $30^{\circ}-80^{\circ}$). Postoperative complications, such as plate impingement, screw loosening, and varus malunion were observed in five patient. We found that all patients achieved bone union, and the mean time-to-union was 13.5 weeks of the treatment. The mean neck-shaft angle was $131.4^{\circ}$ at the 6-month follow-up. According to the Paavolainen method, "good" and "fair" radiographic results each accounted for 38 and 9 of the total patients, respectively. Conclusions: We concluded that locking T-plate fixation leads to satisfactory clinical and radiological outcomes in elderly patients with proximal humeral fractures by providing a larger surface area of contact with the fracture and a more rigid fixation.

Treatment of Fractures of the Lateral Malleolus using Locking Compression Plate (Locking Compression Plate를 이용한 족근 관절 외과 골절의 치료)

  • Ha, Sung-Sik;Hong, Ki-Do;Chung, Nam-Sik;Sim, Jae-Cheon;Ahn, Sang-Cheon
    • Journal of Korean Foot and Ankle Society
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    • v.9 no.1
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    • pp.99-104
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    • 2005
  • Purpose: The purpose of this study was to investigate usefulness of locking compression plate (LCP) as an open reduction technique by evaluating clinical results obtained from the patients with lateral malleolar fracture treated by internal fixation using LCP after open reduction. Materials and Methods: Among the patients with lateral malleolar fracture, the 28 patients who were treated by internal fixation using Locking compression plate after an open reduction and were able to be followed up for more than 6 months were included in this study. Final postoperative evaluation was done based on the Meyer's clinical and radiologic evaluation system. Results: All cases achieved anatomical reduction and fixation of the reduction postoperatively. 28 minutes were taken meaningly from the incision to the fixation of LCP plate after the anatomical reduction. Everage bony union time was 8.2 weaks, and the result was excellent in 23 cases (82%), good in 5 cases (17%) and poor result was abscent according to the criteria of Meyer et al. One case of post traumatic arthritis and one case of superficial infection on the operation site were found, but non-union, delayed union and malunion were not occurred. Conclusion: The internal fixation after open reduction using LCP is an effective treatment method in treating lateral malleolar fracture of the ankle since it offers advantages including easy application and a greater stability due to its capability of maintaining exact anatomical reduction even though the screw does not penetrate the medial cortex of fibular to add the stability and rigidity of the fixation.

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Performance Evaluation of Deferrd Locking for Maintaining Transactional Cache Consistency (트랜잭션 캐쉬 일관성을 유지하기 위한 지연 로킹 기법의 성능 평가)

  • Kwon, Hyeok-Min
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.8
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    • pp.2310-2326
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    • 2000
  • Client-server DBMS based on a data-shipping model can exploit e1ient resources effectively by allowing inter-transaction caching. However, inter-transaction caching raises the need of transactional cache consistency maintenancetTCCM protocol. since each client is able to cache a portion of the database dynamically. Deferred locking(DL) is a new detection-based TCCM scheme designed on the basis of a primary copy locking algorithm. In DL, a number of lock ,ujuests and a data shipping request are combined into a single message packet to minimize the communication overhead required for consistency checking. Lsing a simulation model. the performance of the prolxlsed scheme is compared with those of two representative detection based schemes, the adaptive optimistic concurrency control and the caching two-phase locking. The performance results indicate that DL improves the overall system throughput with a reasonable transaction abort ratio over other detection - based schemes.

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The Finite Element Analysis of Shell Structures Using Improved Shell Element (개선된 쉘 요소를 이용한 쉘 구조의 유한 요소 해석)

  • 허명재;김홍근;김진식
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.13 no.4
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    • pp.449-459
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    • 2000
  • The original Mindlin-type degenerated shell element perform reasonably well for moderately thick shell structures. However, when full integration for analysis of thin shell is used to evaluate the stiffness matrix, the stiffness of shell element is often over-estimated due to shear or membrane locking phenomena. To correct this problem, the formulation of the new degenerated shell element is derived by the combination of two different techniques. The first type of elements(TypeⅠ) has used assumed shear strains in the natural coordinate system to overcome the shear locking problem, the reduced integration technique in in-plane strains(membrane strains) to avoid membrane locking behaviour. Another element(TypeⅡ) has applied the assumed strains to both of membrane strain and transverse shear strains. The improved degenerated shell element has been tested by several numerical problems of shell structures. Numerical results indicate that this shell element shows fast convergence and reliable solutions.

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Analysis of Modified Digital Costas Loop Part I : Performance in the Absence of Noise (변형된 디지털 Costas Loop에 관한 연구 (I) 잡음이 없을 경우의 성능 해석)

  • 정해창;은종관
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.19 no.2
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    • pp.38-50
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    • 1982
  • A new type of digital phase-locked loop (DPLL) called the modified digital Costas loop is proposed and analyzed. The main feature of the proposed loop is that the phase error detector of the loop has linear characteristic. This results from the use of the tan-1 (.) function in the loop. Accordingly, the DPLL can be characterized by a modulo-2$\pi$ linear difference equation. This paper is diveide into two parts. In Part I we describe the proposed system, and analyze the performance of the first-and second-order loops in the absence of noise by the Phase Plane technique. The locking ranges for the DPLL's to achieve exact locking independently of initial conditions have been obtained in closed forms. Also, the false lock and oscillation phenomena occurring under some initial conditions have been considered. These results have been verified by computer simulation. In Part ll we analyze the proposed system in the presence of noise. The steady state probability density function, mean and variance of the phase error have been obtained by solving the Chapman-Kolmogorov equation. These results will be presented in Part ll.

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Resonance Fiber Bragg Grating Sensor system based on Fourier Domain Mode-locking Laser (분광 영역 모드록킹 레이저를 이용한 공진형 광섬유 격자 센서)

  • Choi, Byeong Kwon;Jeon, Min Yong
    • Korean Journal of Optics and Photonics
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    • v.23 no.5
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    • pp.211-216
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    • 2012
  • We report a resonance fiber Bragg sensor interrogation based on a Fourier domain mode-locking (FDML) laser. The FDML laser is constructed based on a conventional ring laser cavity configuration with fiber Fabry-Perot tunable filter (FFP-TF). There are two sensor parts which are composed with two FBGs inside the laser cavity. Each sensor part provides a separate laser cavity for the FDML laser. The resonance frequencies of the laser cavities are 46.687 kHz and 44.340 kHz, respectively. We applied a static and a dynamic strain on the FBG sensor system. The slope coefficients of the measured relative wavelength shift and relative time interval from the static strain are found to be $0.61pm/{\mu}{\epsilon}$ and $0.8ns/{\mu}{\epsilon}$, respectively.

Removal of Entrapped Pacemaker Electrode - One Case Report - (올가미를 이용한 영구 심박조율기 유도전극의 제거 -1 례 보고-)

  • 이인규;성시찬;우종수
    • Journal of Chest Surgery
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    • v.32 no.7
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    • pp.668-670
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    • 1999
  • The most important indication for the removal of the lead-electrode system is the presence of an infection. When an infection occurs, the entire pacemaker system including the impluse generator and lead-electrode system should be removed. The entrapped electrode can be removed by a continous traction, by the use of forceps, snares or baskets, by the use of a locking stylet or a dilator sheath, and by an operation. We report a case that underwent a removal of an entrapped transvenous pacemaker electrode by the use of snaring technique.

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