• Title/Summary/Keyword: Locking-on

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Static Analysis of Timoshenko Beams using Isogeometric Approach

  • Lee, Sang Jin;Park, Kyoung Sub
    • Architectural research
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    • v.16 no.2
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    • pp.57-65
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    • 2014
  • A study on the static analysis of Timoshenko beams is presented. A beam element is developed by using isogeometric approach based on Timoshenko beam theory which allows the transverse shear deformation. The identification of transverse shear locking is conducted by three refinement schemes such as h-, p- and k-refinement and compared to other reference solutions. From numerical examples, the present beam element does not produce any shear locking in very thin beam situations even with full Gauss integration rule. Finally, the benchmark tests described in this study is provided as future reference solutions for Timoshenko beam problems based on isogeometric approach.

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 Analysis of the Treatment Outcomes of Proximal Humeral Fractures with Locking Plates

  • Lee, Kwang-Won;Hwang, Yoon-Sub;Kim, Choon-Myeon;Yang, Dae-Suk;Park, Tae-Soo
    • Clinics in Shoulder and Elbow
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    • v.17 no.1
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    • pp.10-17
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    • 2014
  • Background: The aim of this study was to assess the clinical outcomes after treatment of proximal humeral fractures with locking plates, and to determine which factors influence the clinical and radiological outcomes. Methods: Fifty six patients who were treated with locking plates for proximal humeral fractures and had been followed for more than 1 year were enrolled in this study. We performed functional evaluation using the Constant score and analyzed radiographic results. The following factors that may potentially influence the clinical outcomes were assessed: age, gender, type of fracture, presence of medial metaphyseal comminution, bone mineral density, anatomical reduction, restoration of medial mechanical support, and postoperative complications. Results: The mean Constant score was 70.1 points at the final follow-up. Female gender, 4-part fractures, AO type-C fractures, and fractures with medial metaphyseal comminution were associated with a poor clinical outcome. On the other hand, restoration of medial mechanical support and accurate anatomical reduction had a positive influence on clinical outcomes. Postoperative complications resulted in 3 patients (intra-articular screw perforation: 1 patient, varus deformity with screw loosening: 1 patient, nonunion: 1 patient). Conclusions: When treating proximal humeral fractures with locking plate fixation, following factors: a female gender, Neer type 4-part fracture, AO type C fracture, and medial metaphyseal comminution are important risk factors that surgeons should take into consideration. Factors that contribute to better clinical outcomes of operative treatment for humeral fractures are accurate anatomical reduction and restoration of medial mechanical support.

The Radiologic Comparison of Operative Treatment Using a Hook Plate versus a Distal Clavicle Locking Plate of Distal Clavicle Fracture

  • Yoon, Byungil;Kim, Jae Yoon;Lee, Jae-Sung;Jung, Hyoung Seok
    • Clinics in Shoulder and Elbow
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    • v.21 no.4
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    • pp.227-233
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    • 2018
  • Background: The purpose of this study was to compare the radiologic results of patients who underwent surgery with a hook plate and a locking plate in distal clavicle fractures. Methods: Sixty patients underwent surgical treatment for Neer type IIa, IIb, III, and V distal clavicle fracture. Twenty-eight patients underwent fracture fixation with a hook plate and 32 with a locking plate. Coracoclavicular distance was measured on standard anteroposterior radiographs before and after the surgery, and union was confirmed by radiograph or computed tomography taken at 6 months postoperatively. Other radiologic complications like osteolysis was also checked. Results: Bony union was confirmed in 59 patients out of 60 patients, and 1 patient in the hook plate group showed delayed union. Coracoclavicular distance was decreased more in the hook plate group after surgery (p<0.01). After 6 weeks of the hook plate removal, the coracoclavicular distance was increased a little compared to before metal removal, but there was no difference compared to the contralateral shoulder. Eleven out of 28 patients (39.3%) showed osteolysis on the acromial undersurface in the hook plate group. Conclusions: Both the hook plate group and the locking plate group showed satisfactory radiologic results in distal clavicle fractures. Both hook plate and locking plate could be a good treatment option if it is used in proper indication in distal clavicle fracture with acromioclavicular subluxation or dislocation.

Accuracy improvement of injection parameters for optical complex signal generation using optical injection-locked semiconductor laser (광 주입 파장 잠금 반도체 레이저를 이용한 광학 복소 신호 생성시의 주입 매개 변수 정확도 향상)

  • Cho, Jun-Hyung;Sung, Hyuk-Kee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.3
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    • pp.478-485
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    • 2021
  • An injection locking technology of a semiconductor laser is a promising technology to generate optical complex signals by adjusting optical injection parameters. The extraction of the precise injection parameters plays a key role in the generation of the optical complex signal. Rate equations of semiconductor lasers under optical injection are commonly used to map the injection parameters and the corresponding optical complex signal. The accuracy of the generated optical complex signal on the injection parameters is limited since the rate equations require a locking map-based interpolation method. We propose a novel analytic method, namely rate equation-based direct extraction method, to directly calculate the injection parameters without relying on the locking map-based interpolation method. We achieved 103-times improvement of the signal accuracy by using the proposed method compared to locking-map based interpolation method.

Influences of Water to Cement Ratio and Chemical Admixtures on the Quality of Inter-Locking Block (인터로킹 블록의 품질에 미치는 물시멘트비와 화학혼화제의 영향)

  • 이상태;김기철;신병철;김진선;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10c
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    • pp.157-160
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    • 1998
  • KS F 4419, which is dealt with the Inter-Locking block, states that water to cement ratio for manufacturing inter-locking block should be less than 25% and in KS F4419, the use of admixture is shown to be reluctant to recommend. In this paper, reinvestigation of some regulations in KS F 4419 are carried out. According to the experimental results, as W/C increases, flexural strength and compressive strength are tended to decrease, whereas they increases within certain range, Flexural strength and compressive strength have higher values in 1:2(W/C=35%), 1:4(W/C=45%) and 1:6(W/C=55%) of mix proportions. Moreover they have rather higher values with the containment of high range AE water-reducing agent. The absorption ratios decrease with the increase of W/C and the containment of high range AE water-reducing agent. Therefore, the regulations on the W/C and admixture in KS F 4419 reguire revision.

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Development of Curved Beam Element with Shear Effect (전단효과를 고려한 곡선보 요소 개발)

  • 이석순;구정서;최진민
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.10
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    • pp.2535-2542
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    • 1993
  • Two-noded curved beam elements, CMLC (field-consistent membrane and linear curvature) and IMLC(field-inconsistent membrane and linear curvature) are developed on the basis of Timoshenko's beam theory and curvilinear coordinate. The curved beam element is developed by the separation of the radial deflection into the bending deflection. In the CMLC element, field-consistent axial strain interpolation is adapted for removing the membrane locking. The CMLC element shows the rapid and stable convergence on the wide range of curved beam radius to thickness. The field-consistent axial strain and the separation of radial deformation produces the most efficient linear element possible.

WDM-PON Based on Wavelength Locked Fabry-Perot LDs

  • Lee, Chang-Hee;Mun, Sil-Gu
    • Journal of the Optical Society of Korea
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    • v.12 no.4
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    • pp.326-336
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    • 2008
  • A WDM-PON has been considered as an ultimate solution for access networks. However, there were many technical and practical issues for commercial deployment. These issues were solved with wavelength locked F-P LD and the WDM-PONs employing this optical source were commercialized. These WDM-PON systems have been deployed in Korea, Europe, and US. We reviewed wavelength locking technology and WDM-PON achievements. When we inject spectrum sliced broadband light into an F-P LD, the multimode output is changed to a quasi single mode. Then, we can use the single mode light for WDM signal transmission. The broad spectral gain of the semiconductor gain medium enables a color-free operation of WDM-PON, i.e., an identical ONT can be used for each user. The wavelength locking properties depend on many parameters, especially alignment of injection wavelength to a lasing mode, passband profile of AWG and front facet reflectivity of F-P LD. However, these dependencies can be reduced by proper design of the laser and the injection bandwidth. Thus, WDM-PON systems have been achieved with color-free operation.

Precise control flow protection based on source code (소스코드 기반의 정밀도 높은 실행 흐름 보호 기법)

  • Lee, JongHyup;Kim, Yong Seung
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.5
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    • pp.1159-1168
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    • 2012
  • Control Flow Integrity(CFI) and Control Flow Locking(CFL) prevent unintended execution of software and provide integrity in control flow. Attackers, however, can still hijack program controls since CFI and CFL does not support fine-granularity, context-sensitive protection. In this paper, we propose a new CFI scheme, Source-code CFI(SCFI), to overcome the problems. SCFI provides context-sensitive locking for control flow. Thus, the proposed approach protects software against the attacks on the previous CFI and CFL schemes and improves safety.