The phase field method integrates the Griffith theory and damage mechanics approach to predict crack initiation, propagation, and branching within one framework. No crack tracking topology is needed, and complex crack shapes can be captures without user intervention. In this paper, a detailed description of how the phase field method is implemented with Explicit dynamics into LS-DYNA is provided. The displacement field and the damage field are solved in a staggered approach and the phase field equation is solved every Nth time step (N is refered to as calculation cycle) to save computational time. An N value smaller than 1⁄ 400 of the total time step numbers is suggested. Several simulations are presented to demonstrate the feasibility of this solving scheme.

In recent years computational simulation has taken an increased engineering importance in the seismic evaluation of critical structures. However, accurate nonlinear analyses of large suspension bridges continues to present earthquake engineers with a technically and computationally challenging problem. Application of general purpose nonlinear finite element software often results in computational models which are intractably large and computationally prohibitive. There are also specialized aspects to suspension bridges modeling, such as appropriate gravity initialization, that are not easily solved with general purpose computer programs. To address the simulation model challenges, a reduced order computational model has recently been developed for efficient nonlinear time history analysis. The model employs special element technologies tailored to suspension bridge applications and provides a hybrid implicit-Explicit solution algorithm which can perform appropriate gravity initialization and adeptly handle extreme nonlinearties such as dynamic impact associated with pounding between bridge segments, foundation rocking or member buckling, and provide a framework which is readily migrated to a massively parallel compute environment. The computational model is described and a sample application is presented for the near-field seismic response of the San Francisco- Oakland Bay Bridge Western Crossing (USA).

The combination of implicit meaning-focused input and Explicit instruction has been suggested by recent research as very effective for learning L2 vocabulary; however, the time sequence for such juxtaposition has not been adequately examined through empirical studies. Therefore, this study sought to find the optimal time for combining Explicit and implicit L2 vocabulary instruction using an explanatory mixed-method design. A convenience sample of 62 upper-intermediate EFL learners from three intact classes participated in this study. The Test of Academic Word List (Version A) that assesses Coxhead’ s (2000) Academic Word List (AWL) was administered as a pertest. The reading book, Focus on Vocabulary 2, that has been developed based on the AWL was used for giving meaning-forced input. The target words were Explicitly pre-taught in Class A (n=22), taught concurrent with encountering them in the reading text in Class B (n=20), and post-taught in Class C (n=22). Version B of the AWL Test was used as the posttest and after a 14-day retention interval (RI) as the delayed posttest. Then, 25% of the learners were orally interviewed about their attitudes toward the treatment they received. Quantitative data analysis using one-way ANCOVA revealed that Explicit teaching during the reading was the optimal time and could help learners significantly do better on the immediate and delayed post-tests followed by pre-teaching. Qualitative analysis also verified the obtained quantitative results. The findings of this study imply that Explicit vocabulary teaching during the reading should be practiced by EFL teachers/learners for fostering vocabulary development.

Access-driven attacks are a series of cache-based attacks using fewer measurement samples to extract sensitive key values due to the ability of the attacker to evict or access cache lines compared to the other attacks based on this feature. Knowledge of address offset for the corresponding data blocks in cryptographic libraries is a prerequisite for an adversary to reload or evict cache lines in Intel processors. Preventing the access of attackers to the address offsets can potentially be a countermeasure to mitigate access-driven attacks. In this paper, we demonstrate how to perform the Evict+time attack on Intel x86 CPUs without any privilege of knowing address offsets.

In this study, one Explicit and one implicit finite difference scheme is introduced for the numerical solution of time-fractional Riesz space diffusion equation. The time derivative is approximated by the standard Gr¨, unwald Letnikov formula of order one, while the Riesz space derivative is discretized by Fourier transform-based algorithm of order four. The stability and convergence of the proposed methods are studied. It is proved that the implicit scheme is unconditionally stable, while the Explicit scheme is stable conditionally. Some examples are solved to illustrate the efficiency and accuracy of the proposed methods. Numerical results confirm that the accuracy of present schemes is of order one.

A time integration scheme is proposed for dynamic analysis of linear elastic problems. This method assumes higher order variation of the acceleration at each time step. Two variable parameters are used to increase the stability and accuracy of the method. In the proposed method, second order accuracy and unconditionally stable method is achieved for all values of the assumed parameters with and without numerical damping. Moreover, the proposed method controls numerical dissipation in the higher modes. Finally, the numerical results of the proposed method are compared with two classical methods; namely the average acceleration and the Wilson-q methods.

Dynamical systems with delay are widespread in nature. The study of time-delay induced changes in the collective behavior of systems of coupled nonlinear oscillators is a subject of great interest, both because of its fundamental importance from the point of view of dynamical systems and because of its practical applications. In this paper, an Explicit technique is proposed for numerical solution of nonlocal dynamical systems with time delay. The proposed method is adopted quadratic spline interpolation. Then, the error analysis of the developed method is discussed. It is exploited in the discussion of nonlocal delay Ikeda and Hutchinson models. Finally, the performance of the presented approach is veri ed by applying the error and convergence study for di erent values of fractional order parameters.