• Journal of Auto-vehicle Safety Association
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• v.5 no.1
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• pp.25-30
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• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1188-1191
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• 2003

In this paper, we focus our attention on the improvement of locking time and jitter parameter and propose the new structure of PLL which combined with the FVC, FOVI Matcher(FVC-Output and VCO-input Matching Circuit), Control Circuit and the conventional charge pump PLL. Using fast operation characteristics of the FVC, the circuit matching FVC-Output and VCO-input (FOVI Matcher) made to synchronize very fast. Fast locking time is usually required for application where the PLL has to settle rapidly if they switch from an idle mode to a normal mode and to track high-frequency data bit rate in data recovery systems. After a fast acqusition is achieved by the using the FVC, the conventional PLL operates for removing the phase error between the reference signal and the feedback signal. Therefore this structure can improve the trade-off between acquisition behavior and locked behavior.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.3
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• pp.1-10
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• 1991

The paper is concerned with the analysis of laminated composite shell structures using an improved degenerated shell element. In the formulation of the element stiffness, the combined use of three different techniques was made. They are; 1) an enhanced interpolation of transverse shear strains in the natural coordinate system to overcome the shear locking problem; 2) the reduced integration technique in in-plane strains to avoid the membrane locking behavior; and 3) selective addition of the nonconforming displacement modes to improve the element performances. This element is free of serious shear/membrane locking problems and undesirable compatible/commutable spurious kinematic deformation modes. An incremental total Lagrangian formulation is presented which allows the calculation of arbitrarily large displacements. The resulting non-linear equilibrium equations are solved by the Newton-Raphson method. The versatility and accuracy of this improved degenerated shell element are demonstrated by solving several numerical examples.

• Computational Structural Engineering
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• v.3 no.1
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• pp.97-107
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• 1990

The development of an improved degenerated shell element is presented in this paper. In the formulation of this element, an enhanced interpolation of transverse shear strains in the natural coordinate system is used to overcome the shear locking problem ; the reduced integration technique in in-plane strains is applied to avoid the membrane locking behavior ; and selective addition of the nonconforming displacement modes improve the element performances. This element is free of serious locking problems and undesirable compatible or commutable spurious kinematic deformation modes, and passes the patch tests. To illustrate the performance of this improved degenerated shell element, some benchmark problems are presented. Numerical results indicate that the new element shows fast convergence and reliable solutions.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.3
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• pp.32-41
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• 1995

In the analysis of metal forming processes by the finite element method, there are many numerical instabilities such as element locking, hourglass mode and shear locking. These instabilities may have a bad effect upon accuracy and convergence. The present work is concerned with improvement of stability and efficiency in two-dimensional rigid-plastic finite element method using various type of elemenmts and numerical intergration schemes. As metal forming examples, upsetting and backward extrusion are taken for comparison among the methods: various element types and numerical integration schemes. Comparison is made in terms of stability and efficiency in element behavior and computational efficiency and a new scheme of adaptive directional reduced integration is introduced. As a result, the finite element computation has been stabilized from the viewpoint of computational time, convergency, and numerical instability.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.04a
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• pp.18-23
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• 1990

The paper is concerned with the elasto-plastic and geometrically nonlinear analysis of shell structures using an improved degenerated shell element. In the formulation of the improved degenerated shell element, an enhanced interpolation of transverse shear strains in the natural coordinate system is used to overcome the shear locking problems; the reduced integration technique in in-plane strains is applied to avoid membrane locking behavior; selective addition the nonconforming displacement modes improve the element performances. This element is free of serious locking problems and undesirable compatible or commutable spurious kinematic deformation modes and passes the patch tests. An incremental total Lagrangian formulation is presented which allows the calculation of arbitrarily large displacements and rotations. The resulting nonlinear equations are solved by the Newton-Raphson solution scheme. The versatility and accuracy of this improved degenerated shell element are demonstrated by solving several numerical examples.

• Computational Structural Engineering
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• v.3 no.3
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• pp.113-123
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• 1990

The paper is concerned with the elasto-plastic and geometrically nonlinear analysis of shell structures using an improved degenerated shell element. In the formulation of the element stiffness, the combined use of three different techniques was made. They are; 1) an enhanced interpolation of transverse shear strains in the natural coordinate system to overcome the shear locking problem ; 2) the reduced integration technique in in-plane strains to avoid the membrane locking behavior ; and 3) selective addition of the nonconforming displacement modes to improve the element performances. This element is free of serious shear/membrane locking problems and undesirable compatible/commutable spurious kinematic deformation modes. In the formulation for plastic deformation, the concept of a layered element model is used and the material is assumed von Mises yield criterion. An incremental total Lagrangian formulation is presented which allows the calculation of arbitrarily large displacements and rotations. The resulting non-linear equilibrium equations are solved by the Netwon-Raphson method combined with load or displacement increment. The versatility and accuracy of this improved degenerated shell element are demonstrated by solving several numerical examples.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.12
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• pp.3792-3803
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• 1996

Since the skew beam element has two curvatures which are a curvature and a torsion, spatial behavior of curved beam which cannot be included in one plane can be anlayzed by emploting the skew beam element. The $C^{0}$-continuous skew beam element shows the stiffness locking phenomenon when full integration is employed. The locking phenomenpn is characterized by two typical phenomena ; one is the much smaller displacement thant the exact one and theother is the undelation phenomenon is stress distribution. In this paper, we examine how unmatched coefficient in the constrained energy brings about the locking by Reduced Minimization theory. We perform the numerical ones. These comparisons show that uniformly full integration(UFI), which employs full integration for the constrained energy, entails the locking phenomenon. But the use of uniformly reduced integration(URI) of selectively reduced integration(SRI), which employs reduced integration for constrained energy, does not produce the significant errors of displacements of the undulation phenomenon in stress distribution since they do not entails the locking, Additionally, the error due to the approximated parameters for describing the geometry of skew beam is examined.d.

• Design & Manufacturing
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• v.10 no.1
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• pp.1-6
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• 2016

In this study, the modification structure design of insulation displacement connector developed was considered for simplification of assembly process. The modified connector consisted terminal, wafer and fitting nails. The separation behavior under locking condition for pitch 1.25mm wire to board connector was measured and the apparatus for the test was made. The maximum restraining force was measured about 4.5kgf that was bigger value than the specification limit. And the pulling force of a wire was also indicated about 2.3kgf.

• KSCI Review
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• v.1 no.2
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• pp.95-107
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• 1995

The concurrency control can be critical to the performance of transaction processing systems. Conventional locking takes the blocking phenomenon, where waiting transactions continue to hold locks and block other transactions from progressing. The proposed scheme reduces the blocking probability by deferring the blocking behavior of transactions to the later stages of their execution. The transaction execution can be divided into a nonblocking phase where transactions wait for locks but do not block other transactions and a blocking phase as in conventional locking. However data accessed during the nonblocking phase can lead to transaction abort. By properly balancing the blocking and abort effects, the proposed scheme can lead to better performance than either the conventional locking or the optimistic concurrency control(OCC) scheme at all data and resource contention levels.