Tengjin Zhao¹, Jing Zhang¹, Zhilin Li², Zhiyue Zhang^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.1, pp. 83-104, 2019, DOI:10.32604/cmes.2019.04483

Abstract The validity of the tangent linear model (TLM) is studied numerically using the example of the Lorenz equations in this paper. The relationship between the limit of the validity time of the TLM and initial perturbations for the Lorenz equations is investigated using the Monte Carlo sampling method. A new error function between the nonlinear and the linear evolution of the perturbations is proposed. Furthermore, numerical sensitivity analysis is carried to establish the relationship between parameters and the validity of the TLM, such as the initial perturbation, the prediction time, the time step size and More >

Xiang Li¹, Mei-E Fang^1,2,*, QIan Qi²

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.1, pp. 45-62, 2019, DOI:10.32604/cmes.2019.05659

Abstract In this article, we adopt the C-type spline of degree 2 to model and blend basic shapes including conics and circle arcs. The C-type spline belongs to the ωB-spline category of splines that are capable of blending polynomial, trigonometric and hyperbolic functions. Commonly used basic shapes can be exactly represented by these types of splines. We derive explicit formulas for the convenience of modeling the basic curves. The entire blending curve is C¹-continuous. In comparison with the existing best blending method by rational G² splines, which are rational splines of degree 3, the proposed method allows simpler… More >

R. Agalya¹, R. Muthaiah^2,*, D. Muralidharan³

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.1, pp. 25-43, 2019, DOI:10.32604/cmes.2019.05616

Abstract In today’s modern design technology, post-silicon validation is an expensive and composite task. The major challenge involved in this method is that it has limited observability and controllability of internal signals. There will be an issue during execution how to address the useful set of signals and store it in the on-chip trace buffer. The existing approaches are restricted to particular debug set-up where all the components have equivalent prominence at all the time. Practically, the verification engineers will emphasis only on useful functional regions or components. Due to some constraints like clock gating, some… More >

Jin Yang¹, Tao Li¹, Gang Liang^1,*, Wenbo He², Yue Zhao³

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.1, pp. 1-23, 2019, DOI:10.32604/cmes.2019.04727

Abstract Deep Learning presents a critical capability to be geared into environments being constantly changed and ongoing learning dynamic, which is especially relevant in Network Intrusion Detection. In this paper, as enlightened by the theory of Deep Learning Neural Networks, Hierarchy Distributed-Agents Model for Network Risk Evaluation, a newly developed model, is proposed. The architecture taken on by the distributed-agents model are given, as well as the approach of analyzing network intrusion detection using Deep Learning, the mechanism of sharing hyper-parameters to improve the efficiency of learning is presented, and the hierarchical evaluative framework for Network More >

M. Nagaraj^1,*, A. John Presin Kumar², C. Ezilarasan³, Rishab Betala⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 679-692, 2019, DOI:10.31614/cmes.2019.04924

Abstract The paper proposes a simulated 3D Finite Element Model (FEM) for drilling of Nickel based super alloy known as Nimonic C-263. The Lagrangian finite element model-based simulations were performed to determine the thrust force, temperature generation, effective stress, and effective strain. The simulations were performed according to the L27 orthogonal array. A perfect plastic work piece was assumed, and the shape is considered to be cylindrical. The spindle speed, feed rate, and point angle were considered as the input parameters. The work piece was modeled by Johnson–Cook (JC) material model and tungsten carbide (WC) was More >

Biao Wang^1,*, Yongjian Yang¹, Hesong Huang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 649-678, 2019, DOI:10.31614/cmes.2019.05671

Abstract To calculate the diffusion law of chaff cloud launched by aircraft, taking rectangular chaff as an example, the diffusion model of chaff cloud is established in this paper. Firstly, the coordinate systems of chaff are defined and the motion model of chaff is established. The motion model mainly includes chaff motion equation and rotation equation, which are obtained by combining the aerodynamic moment and aerodynamic damping. Then, the influence of multi-chaff aerodynamic interference on the movement of chaff is analyzed. Finally, considering the influence of overlap area between chaffs and chaff spacing on the aerodynamic More >

Tuanjie Li^1,*, Yan Zhang¹, Jiaxing Zhou¹

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 583-598, 2019, DOI:10.31614/cmes.2018.04891

Abstract In order to satisfy the high efficiency and high precision of collaborative robots, this work presents a novel trajectory planning method. First, in Cartesian space, a novel velocity look-ahead control algorithm and a cubic polynomial are combined to construct the end-effector trajectory of robots. Then, the joint trajectories can be obtained through the inverse kinematics. In order to improve the smoothness and stability in joint space, the joint trajectories are further adjusted based on the velocity look-ahead control algorithm and quintic B-spline. Finally, the proposed trajectory planning method is tested on a 4-DOF serial collaborative More >

Hanbo Zhu^1,2, Changqing Miao^1,2,*, Meiling Zhuang^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 471-491, 2019, DOI:10.31614/cmes.2019.04382

Abstract Current building design codes allow the appearance of structural and nonstructural damage under design basis earthquakes. The research regarding probabilistic seismic loss estimation in domestic building structure is urgent. The evaluation in this paper is based on a 11-story reinforced concrete office building, incremental dynamic analysis (IDA) is conducted in Perform 3D program using models capable to simulate all possible limit states up to collapse. Next, the probability distribution of post-earthquake casualties, rebuild costs repair costs and business downtime loss are calculated in PACT software for the studied building considering the modified component vulnerability groups More >

Liwei Wu¹, Dan Huang^1,*, Yepeng Xu¹, Lei Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 561-581, 2019, DOI:10.31614/cmes.2019.04347

Abstract Strain hardening and strain rate play an important role in dynamic deformation and failure problems such as high-velocity impact cases. In this paper, a non-ordinary state-based peridynamic model for failure and damage of concrete materials subjected to impacting condition is proposed, taking the advantages of both damage model and non-local peridynamic method. The Holmquist-Johnson-Cook (HJC) model describing the mechanical character and damage of concrete materials under large strain, high strain rate and high hydrostatic pressure was reformulated in the framework of non-ordinary state-based peridynamic theory, and the corresponding numerical approach was developed. The proposed model More >

Chunlong Hu^1,*, Jianjun Chen¹, Xin Zuo¹, Haitao Zou¹, Xing Deng¹, Yucheng Shu²

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 547-559, 2019, DOI:10.31614/cmes.2019.04032

Abstract Micro-expression recognition has attracted growing research interests in the field of compute vision. However, micro-expression usually lasts a few seconds, thus it is difficult to detect. This paper presents a new framework to recognize micro-expression using pyramid histogram of Centralized Gabor Binary Pattern from Three Orthogonal Panels (CGBP-TOP) which is an extension of Local Gabor Binary Pattern from Three Orthogonal Panels feature. CGBP-TOP performs spatial and temporal analysis to capture the local facial characteristics of micro-expression image sequences. In order to keep more local information of the face, CGBP-TOP is extracted based on pyramid sub-regions… More >