• Title/Summary/Keyword: Locking-on

Search Result 538, Processing Time 0.031 seconds

Long-term Effects on the Cervical Spine after Anterior Locking Plate Fixation (경추 전방 잠금식 금속판이 장기적으로 경추에 미치는 영향)

  • Kim, Keun Su
    • Journal of Korean Neurosurgical Society
    • /
    • v.30 no.4
    • /
    • pp.493-500
    • /
    • 2001
  • Objective : Anterior cervical locking plates are the devices for achieving anterior cervical spinal fusion. This study was conducted to evaluate the locking plate system regarding its long-term advantages and disadvantages in the view of interbody fusion rate, hardware-related failures, vertebral change close to the fusion segment and postoperative complications. Method : Eight-six patients, operated from Jan., 1996 to Jun. 1998, were followed-up for more than two years. All of the cases were fused with iliac bone graft and ORION locking plate(Sofamor Danek USA, Inc., Memphis, TN) fixation. The patients were discharged or transferred to rehabilitation department 2-7 days after operation. A comprehensive evaluation of the interbody fusion state, instrument failure, vertebral change and postoperative complications were made by direct interview and cervical flexion-extension lateral plain films. Results : There were 55 male and 31 female with a mean age of 45 years(18-75 years). The mean follow-up period was 29 months(24-43 months). Various disorders that were operated were 40 cervical discs, 6 cervical stenosis including OPLL, 2 infections, and 38 traumas. Fusion level was single in 59 cases, two levels of each disc space in 15 cases, and two levels after one corpectomy in 12 cases. There was no instrument failure. Pseudoarthrosis was observed in two cases(2%) without radiological instability. The other patients(98%) showed complete cervical fusion with stable instrument. Mild settling of interbody graft with upward migration of screws was found in 12 cases(14%). Anterior bony growth at the upper segment was found in 5 cases(6%). Postoperative foreign body sensation or dysphagia was observed in 12 cases(4%), and disappeared within one month in 7 cases and within six months in 4 cases. One patient complained for more than six months and required reoperation to remove paraesophageal granulation tissue. Conclusion : The results show that Orion cervical locking plate has some disadvantages of upward migration of screws, anterior bony growth at the upper segment, or possibility of esophageal compression even though it has advantages of high interbody fusion rate or low instrument failure. Author believe that anterior cervical locking plate in the future should be thinner, and should have short end from the screw hole, and movable screw with adequate stability.

  • PDF

A Framework for Concurrency Control and Writing Authority Control in Collaborative Writing Systems (공동저작 시스템에서의 동시성 제어와 쓰기 권한 제어)

  • Yoo, Jae-Hong;Sung, Mee-Young
    • The Transactions of the Korea Information Processing Society
    • /
    • v.7 no.2
    • /
    • pp.347-354
    • /
    • 2000
  • This paper presents the efficient mechanisms for concurrency control and writing authority control in collaborative writing system are represented by the tree structures which consist of the logical objects and the content objects connected to the terminal objects of trees. For concurrency control, we adopted the approach to extend the multiple-granularity-locking-scheme. This scheme allows us to lock any objects at each level of the hierarchy. We also defined the locking compatibility table by analysing the operations applicable to any objects at each level of the hierarchy. We finally suggest the extended-multiple-granularity-locking mechanism which uses the locking compatibilility table for deciding to lock an object. This scheme gives the benefit to maximize the possibility of concurrent accessing to the shared objects. In addition, we suggest a mechanism for writing authority control which prohibits the Non-Group users from modifying the shared objects based on the concept of Group/Non-Group The proposed mechanism allows us to protect copyright very reasonably.

  • PDF

A Study on the Wide-band Fast-Locking Digital PLL Design (광대역 고속 디지털 PLL의 설계에 대한 연구)

  • Ahn, Tae-Won
    • 전자공학회논문지 IE
    • /
    • v.46 no.1
    • /
    • pp.1-6
    • /
    • 2009
  • This paper presents the digital PLL architecture and design for improving the frequency detection range and locking time for wide-band frequency synthesizer applications. In this research, a wide-range digital logic quadricorrelator is used for wide-band and fast frequency detector and sigma-delta modulator with 2-bit up-down counter is adopted for DCO control. The proposed digital PLL reduces the phase noise from quantization effect and is suitable for implementation of wide-band fast-locking as well as low power features, which is in high demand for mobile multimedia applications.

A Research on Predicting Dynamic Behavior of Door Locking System for Side Impact Safety

  • Kwak, K.T.;Choi, D.W.;Seo, S.W.
    • Journal of Auto-vehicle Safety Association
    • /
    • v.5 no.1
    • /
    • pp.25-30
    • /
    • 2013
  • The main purpose of this research is to predict dynamic behavior of door locking system for side impact safety and the design process to avoid door opening is introduced. The equations of motion that represent the system are obtained from the energy equation. From them, the motion of door handle is predicted by using Runge-Kutta $4^{th}$ order method and the simulation result is compared with the real crash data. Also, the design guide to define the properties of door locking system from the standpoint of avoiding door opening phenomenon is introduced.

A Turbine-Blade-Balancing Problem with Some Locking Blades (고정형 블레이드가 있는 터빈의 블레이드 균형화 문제)

  • Choi, Won-Joon
    • IE interfaces
    • /
    • v.14 no.2
    • /
    • pp.140-147
    • /
    • 2001
  • In the turbine-blade manufacturing industry, turbine-blades are machined and then are assembled to form a circular roll of blades. The roll of blades should be balanced as much as possible, since otherwise the efficiency of the turbine generator might be damaged. A locking blade is a blade whose location is fixed and a non-locking blade is a blade whose location can be freely changed. In this paper, we study methods for balancing the weights of the rotating blades for a turbine where some blades are locking blades. The turbine-blade balancing problem is formulated into a mixed-integer programming problem, which turns out to be NP-hard. A heuristic method based on the number partitioning algorithm is developed and the computational experiments show very promising results.

  • PDF

DEVELOPMENT OF A MACHINE VISION SYSTEM FOR AN AUTOMOBILE PLASTIC PART INSPECTION

  • ANDRES N.S.;MARIMUTHU R.P.;EOM Y.K.;JANG B.C.
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2005.06a
    • /
    • pp.1131-1135
    • /
    • 2005
  • Since human is vulnerable to emotional, physical and environmental distractions, most human inspectors cannot sustain a consistent 8-hour inspection in a day specifically for small components like door locking levers. As an alternative for human inspection, presented in this study is the development of a machine vision inspection system (MVIS) purposely for door locking levers. Comprises the development is the structure of the MVIS components, designed to meet the demands, features and specifications of door locking lever manufacturing companies in increasing their production throughput upon keeping the quality assured. This computer-based MVIS is designed to perform quality measures of detecting missing portions and defects like burr on every door locking lever. NI Vision Builder software for Automatic Inspection (AI) is found to be the optimum solution in configuring the needed quality measures. The proposed software has measurement techniques such as edge detecting and pattern-matching which are capable of gauging, detecting missing portion and checking alignment. Furthermore, this study exemplifies the incorporation of the optimized NI Builder inspection environment to the pre-inspection and post-inspection subsystems.

  • PDF

A Fast-Locking Fractional-N PLL with Multiple Charge Pumps and Capacitance Scaling Scheme (Capacitance Scaling 구조와 여러 개의 전하 펌프를 이용한 고속의 ${\Sigma}{\Delta}$ Fractional-N PLL)

  • Kwon, Tae-Ha
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.43 no.10 s.352
    • /
    • pp.90-96
    • /
    • 2006
  • A novel ${\Sigma}{\Delta}$ fractional-N PLL architecture for fast locking and fractional spur suppressing is proposed based on the capacitance scaling scheme. It changes the effective capacitance of loop filter (LF) by increasing and decreasing current to the capacitor via different paths with multiple charge pumps. The effective capacitance of loop filter (LF) can be scaled up/down depending on operating status while keeping LF capacitors small enough to be integrated into a single PLL chip. Fractional spurs suppressing have been achieved by reducing the magnitude of charge pump current when the PLL is in-lock without degrading fast locking characteristic. It has been simulated by HSPICE in a CMOS $0.35{\mu}m$ process, and shows flat locking time is less than $8{\mu}s$ with the small size of LF capacitors, 200pF and 17pF, and $2.8k{\Omega}$ resistor.

The Outcomes of Proximal Humerus Fractures with Medial Metaphyseal Disruption Treated with Fibular Allograft Augmentation and Locking Plate

  • Kim, Doo Sup;Yoon, Yeo Seung;Kang, Sang Kyu;Jin, Han Bin;Lee, Dong Woo
    • Clinics in Shoulder and Elbow
    • /
    • v.20 no.2
    • /
    • pp.90-94
    • /
    • 2017
  • Background: Proximal humerus fracture is considered to be the third most common fracture for patients aged 65 years or older. Conservative treatment has been known to treat most of humerus fracture. However, fractures with severe displacement or dislocation may require surgical treatment. Intramedullary fibular allograft with a locking plate is frequently used in patients accompanying medial metaphyseal disruption. In this study, author intends to evaluate clinical and imaging results based on patients who underwent surgical treatment using fibular allograft with a locking plate. Methods: This study is conducted prospectively at Wonju Severance Christian Hospital, targeting patients who previously underwent surgical treatment using open reduction and intramedullary fibular allograft with a locking plate between 2011 and 2015. A total of 26 patients were evaluated on the following: postoperational clinical assessment measuring Constant score, American Shoulder and Elbow Society (ASES) score, and the Disabilities of the Arm, Shoulder and Hand (DASH) score. Postoperational imaging assessments are evaluated via measuring the neck-shaft angle. The study subject were Neer classification type 3, 4 proximal humerus fracture cases with disrupted medial hinge and having cortical comminution in the region of the surgical neck. Results: The average period of progression was 22.5 months, and the average age of patients was 72.6 years. At the final follow-up, the average Constant, average ASES, and average DASH scores were 80.1, 78.5, and 20.6 respectively. The average neck-shaft angle was $127.5^{\circ}$. Conclusions: In conclusion, fibular allograft augmentation with a locking plate showed satisfying results in both clinical and imaging studies.

Design and Implementation of Real-Time Static Locking Protocol for Main-memory Database Systems (주기억장치 데이타베이스 시스템을 위한 실시간 정적 로킹 기법의 설계 및 구현)

  • Kim, Young-Chul;You, Han-Yang;Kim, Jin-Ho;Kim, June;Seo, Sang-Ku
    • Journal of KIISE:Databases
    • /
    • v.29 no.6
    • /
    • pp.464-476
    • /
    • 2002
  • Main-memory database systems which reside entire databases in main memory are suitable for high-performance real-time transaction processing. If two-phase locking(2PL) as concurrency control protocol is used for the transactions accessing main-memory databases, however, the possibility of lock conflict will be low but lock operations become relatively big overhead in total transaction processing time. In this paper, We designed a real-time static locking(RT-SL) protocol which minimizes lock operation overhead and reflects the priority of transactions and we implemented it on a main-memory real-time database system, Mr.RT. We also evaluate and compare its performance with the existing real-time locking protocols based on 2PL such as 2PL-PI and 2PL-HP. The extensive experiments reveal that our RT-SL outperforms the existing ones in most cases.

Investigation of the Vortex Shedding with the Shear Building (전단건물을 이용한 와류발산현상 파악)

  • Lee, Sang-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.11 no.5
    • /
    • pp.1785-1790
    • /
    • 2010
  • To study the vortex induced vibrations the wind tunnel and the two story shear building were designed and built. The wind tunnel was designed to generate the wind speed up to 24 m/s, and the building was designed to have the two lowest natural frequencies within the range of the vortex frequencies generated by the wind tunnel. The resonance behaviors by the locking-on phenomena were observed during the wind tunnel tests of the shear building with the cylinder attached. From the locking-on phenomena observed it is found that the effects of the amplitudes and the frequencies of the cylinders should be considered on the forces generated by the vortex shedding.