F. Aymerich¹, M. Serra²

CMES-Computer Modeling in Engineering & Sciences, Vol.13, No.1, pp. 49-66, 2006, DOI:10.3970/cmes.2006.013.049

Abstract The study reported in this paper explores the potential of Ant Colony Optimization (ACO) metaheuristic for stacking sequence optimization of composite laminates. ACO is a recently proposed population-based search approach able to deal with a wide range of optimization problems, especially of a combinatorial nature, and inspired by the natural foraging behavior of ant colonies. ACO search processes, in which the activities of real ants are simulated by means of artificial agents that communicate and cooperate through the modification of the local environment, were implemented in a specifically developed numerical algorithm aimed at the lay-up optimization (based on a strain… More >

Maria João M. Vasconcelos¹, João Manuel R. S. Tavares¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.1, pp. 3-4, 2009, DOI:10.3970/icces.2009.010.003

Abstract In the last years, researchers from the Computational Vision working field have been developing new methods to perform image segmentation for human motion analysis. The development of computational techniques suitable to automatically identify the structures involved is necessary to obtain more representative and robust features to be further used in the analysis of human motion from image sequences.
The first step of human motion analysis from image sequences is strongly related with image segmentation. In fact, the first goal of any system designed for this aim is the identification of the structures’ features to be analysed in the image frames.… More >

Khouloud Cheour^1,*, Mustapha Assarar¹, Daniel Scida¹, Rezak Ayad¹, Xiaolu Gong²

Journal of Renewable Materials, Vol.7, No.9, pp. 877-889, 2019, DOI:10.32604/jrm.2019.06826

Abstract The aim of this study is to show the interest of the mechanical and dynamical properties of glass-flax hybrid composites. Therefore, various staking sequences of glass-flax hybrid composites were manufactured and tested in free vibrations. The damping coefficients were identified by fitting the experimental responses of free-free bending vibrations. The obtained results show that the staking sequences and the position of flax fiber layers in the hybrid composites changed the properties, so a classification of different stacking sequences was established. In fact, the hybrid laminate made of two glass external layers placed on both sides of four flax layers is… More >

Liqiang Lin¹, Xianqiao Wang², Xiaowei Zeng^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.2, pp. 203-220, 2014, DOI:10.3970/cmes.2014.098.203

Abstract The Voronoi tessellation is employed to describe cellular patterns and to simulate cell division and cell remodeling in epithelial tissue. First, Halton sequence is utilized to generate the random generators of Voronoi cell points. The centroidal Voronoi cell center is obtained by probabilistic Lloyd's method and polygonal structure of cell distribution is modeled. Based on the polygonal shape of cells, the instantaneous mechanism of cell division is applied to simulate the cell proliferation and remodeling. Four kinds of single-cell division algorithms are designed with the consideration of cleavage angle. From these simulations, we find that cell topological structure varies case… More >

Raquel R. Pinho¹, João Manuel R. S. Tavares¹

CMES-Computer Modeling in Engineering & Sciences, Vol.46, No.1, pp. 51-76, 2009, DOI:10.3970/cmes.2009.046.051

Abstract This work addresses the problem of tracking feature points along image sequences. In order to analyze the undergoing movement, an approach based on the Kalman filtering technique has been used, which basically carries out the estimation and correction of the features' movement in every image frame. So as to integrate the measurements obtained from each image into the Kalman filter, a data optimization process has been adopted to achieve the best global correspondence set. The proposed criterion minimizes the cost of global matching, which is based on the Mahalanobis distance. A management model is employed to manage the features being… More >

K. Garikipati¹, V.S. Rao², M.Y. Hao³, E. Ibok⁴, I. de Wolf⁵, R. W. Dutton⁶

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.1, pp. 65-84, 2000, DOI:10.3970/cmes.2000.001.065

Abstract This work is based upon a careful rendering of mechanics and mathematics to describe the phenomena that influence the stress engendered by the Shallow Trench Isolation process. The diffusion-reaction problem is posed in terms of fundamental mass balance laws. Finite strain kinematics is invoked to model the large expansion of SiO₂, dielectrics are modelled as viscoelastic solids and annealing-induced density relaxation of SiO₂ is incorporated as a history-dependent process. A levelset framework is used to describe the moving Si/SiO₂ interface. Sophisticated finite element methods are employed to solve the mathematical equations posed for each phenomenon. These include the incorporation of… More >

Ming Wan¹, Jiangyuan Yao^2,*, Yuan Jing¹, Xi Jin^3,4

CMC-Computers, Materials & Continua, Vol.55, No.3, pp. 447-463, 2018, DOI: 10.3970/cmc.2018.02195

Abstract As the main communication mediums in industrial control networks, industrial communication protocols are always vulnerable to extreme exploitations, and it is very difficult to take protective measures due to their serious privacy. Based on the SDN (Software Defined Network) technology, this paper proposes a novel event-based anomaly detection approach to identify misbehaviors using non-public industrial communication protocols, and this approach can be installed in SDN switches as a security software appliance in SDN-based control systems. Furthermore, aiming at the unknown protocol specification and message format, this approach first restructures the industrial communication sessions and merges the payloads from industrial communication… More >

Jieren Cheng^1,2, Ruomeng Xu^1,*, Xiangyan Tang¹, Victor S. Sheng³, Canting Cai¹

CMC-Computers, Materials & Continua, Vol.55, No.1, pp. 95-119, 2018, DOI:10.3970/cmc.2018.055.095

Abstract Distributed denial-of-service (DDoS) is a rapidly growing problem with the fast development of the Internet. There are multitude DDoS detection approaches, however, three major problems about DDoS attack detection appear in the big data environment. Firstly, to shorten the respond time of the DDoS attack detector; secondly, to reduce the required compute resources; lastly, to achieve a high detection rate with low false alarm rate. In the paper, we propose an abnormal network flow feature sequence prediction approach which could fit to be used as a DDoS attack detector in the big data environment and solve aforementioned problems. We define… More >

Zhengong Zhou¹, Shuang Tian^1,2, Jiawei Zhang³

CMC-Computers, Materials & Continua, Vol.52, No.2, pp. 105-121, 2016, DOI:10.3970/cmc.2016.052.105

Abstract The methods of numerical simulation and test are combined to analyze the impact behavior of glass fiber reinforced aluminum alloy laminate (GLARE). A new failure criteria is proposed to obtain the impact failure of GLARE, and combined with material progressive damage method by writing code of LS-DYNA. Low velocity impact test of GLARE is employed to validate the feasibility of the finite element model established. The simulation results have been shown that progressive damage finite element model established is reliable. Through the application of the finite element model established, the delamination of GLARE evolution progress is simulated, various failure modes… More >

CMC-Computers, Materials & Continua, Vol.47, No.1, pp. 45-63, 2015, DOI:10.3970/cmc.2015.047.045

Abstract A new theory of strain hardening is developed. Important in its own right, the strain hardening solution is also of decisive use in rigorously defining the historically broad concepts of yield stress and failure stress. Under ideal conditions yield stress is found to represent a 3rd order transition. Failure stress is an explicit "failure of function" criterion rather than just being the primitive notion of breaking into pieces. Computational extensions and opportunities are discussed. More >