J. M. F. Trindade¹, J. C. F. Pereira²

CMES-Computer Modeling in Engineering & Sciences, Vol.20, No.1, pp. 1-10, 2007, DOI:10.3970/cmes.2007.020.001

Abstract In this paper, we discuss the efficiency and speed-up of parallel-in-time calculations of the unsteady incompressible Navier-Stokes equations in a PC-cluster. The parallel-in-time method is based on the alternate use of coarse global sequential solvers with fine local parallel ones in an iterative predictor-corrector fashion. Therefore, the efficiency of parallel calculations is strongly dependent on the number of iterations required for convergence. The one-dimensional scalar transport equation and the two-dimensional incompressible unsteady form of the Navier-Stokes equations were used to conduct numerical experiments to derive some conclusions concerning the accuracy and convergence of the iterative method. A simple performance model… More >

Y.F. Nie¹, S. Chang¹, X.K. Fan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.19, No.2, pp. 135-144, 2007, DOI:10.3970/cmes.2007.019.135

Abstract A new parallel mechanism for Node-based Seamless Finite Element Method was proposed in this paper, which possessed the following three prominent points: realizing the workload balance for the parallel processes naturally, achieving synchronization of all the schedules under complex parallel environment, and filling up the gap between pre-processing and main processing. To support the scheme, three specific solutions of the parallel mechanism were proposed in this paper, all of which achieved the highly efficient parallel seamless connection between the FEM mesh generation process and structure analysis process. Two of the three schemes, i.e. dynamic scheme and self-adaptive scheme, enabled both… More >

Brahim DENNAI^1*, Mohammed EL Bizani BELBOUKHARI¹ , Tawfiq CHEKIFI¹, Rachid KHELFAOUl¹

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.3, pp. 102-110, 2016, DOI:10.3970/fdmp.2016.012.102

Abstract Microfluidic systems are used and exploited in various fields, as they are highly specific and developed in their use. The micro devices are used in various analyzes of medical disciplines, chemical and other fields. Our research team "MAAt" within ENERGARID laboratory is in the process of triggered several lines of research in this area, the micro-mixing, separation of micro particles, droplet production. For that, we need tools and micro devices to study the phenomena.. In this work, we present a theoretical study and numerical simulation of micro device (micro diode Tesla). A Diode Tesla is similar to a heart valve… More >

Carole Planchette¹, Elise Lorenceau¹, Günter Brenn²

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.3, pp. 279-302, 2011, DOI:10.3970/fdmp.2011.007.279

Abstract This work is dedicated to a general description of collisions between two drops of immiscible liquids. Our approach is mainly experimental and allows us to describe the outcomes of such collisions according to a set of relevant parameters. Varying the relative velocity U as well as the impact parameter X we can build for each pair of investigated liquids a nomogram X,U showing three possible regimes: coalescence, head-on separation and off-center separation. In this paper, we also study the influence of the liquid properties, i.e. viscosity, density, surface and interfacial tensions using a set of aqueous glycerol solutions together with… More >

M. Kriaa¹, M. El Alami^1,2, M. Najam¹, E. Semma³

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.2, pp. 125-140, 2011, DOI:10.3970/fdmp.2011.007.125

Abstract In this paper a numerical study of natural convection in a two dimensional convergent channel, with or without rectangular block, is carried out. The block is placed at the channel outlet and its thermal conductivity is set equal to that of air. One of channel planes is heated at constant temperature T_H. The other one is maintained cold at T_C < T_H. The governing equations are solved using a finite volume method and the SIMLEC algorithm for the velocity-pressure coupling is used. Special emphasis is given to detail the effect of the block size and Rayleigh number on the dynamics… More >

Ashwinth Janarthanan^1,*, Dhananjay Kumar¹

CMC-Computers, Materials & Continua, Vol.60, No.3, pp. 895-912, 2019, DOI:10.32604/cmc.2019.06805

Abstract Efficient aggregation in wireless sensor nodes helps reduce network traffic and reduce energy consumption. The objective of this work Localization Based Evolutionary Routing (LOBER) is to achieve global optimization for aggregation and WMSN lifetime. Improved localization is achieved by a novel Centroid Based Octant Localization (CBOL) technique considering an arbitrary hexagonal region. Geometric principles of hexagon are used to locate the unknown nodes in the centroid positions of partitioned regions. Flower pollination algorithm, a meta heuristic evolutionary algorithm that is extensively applied in solving real life, complex and nonlinear optimization problems in engineering and industry is modified as Enhanced Flower… More >

Sheng Bin^1,*, Gengxin Sun¹, Ning Cao², Jinming Qiu², Zhiyong Zheng³, Guohua Yang⁴, Hongyan Zhao⁵, Meng Jiang⁶, Lina Xu⁷

CMC-Computers, Materials & Continua, Vol.60, No.2, pp. 659-674, 2019, DOI:10.32604/cmc.2019.05858

Abstract Recommendation system is one of the most common applications in the field of big data. The traditional collaborative filtering recommendation algorithm is directly based on user-item rating matrix. However, when there are huge amounts of user and commodities data, the efficiency of the algorithm will be significantly reduced. Aiming at the problem, a collaborative filtering recommendation algorithm based on multi-relational social networks is proposed. The algorithm divides the multi-relational social networks based on the multi-subnet complex network model into communities by using information dissemination method, which divides the users with similar degree into a community. Then the user-item rating matrix… More >

Jinlan Xu¹, Ningning Sun¹, Laixin Shu¹, Timon Rabczuk², Gang Xu^1,*

CMC-Computers, Materials & Continua, Vol.60, No.2, pp. 615-632, 2019, DOI:10.32604/cmc.2019.04464

Abstract Trimming techniques are efficient ways to generate complex geometries in Computer-Aided Design (CAD). In this paper, an improved integration for trimmed geometries in isogeometric analysis (IGA) is proposed. The proposed method can improve the accuracy of the approximation and the condition number of the stiffness matrix. In addition, comparing to the traditional approaches, the trimming techniques can reduce the number of the integration elements with much fewer integration points, which improves the computational efficiency significantly. Several examples are illustrated to show the effectiveness of the proposed approach. More >

Haipeng Chen¹, Kexiong Liu², Chunyang Ma³, Yu Han⁴, Jian Su^5,*

CMC-Computers, Materials & Continua, Vol.57, No.2, pp. 195-204, 2018, DOI:10.32604/cmc.2018.03592

Abstract Recently, object identification with radio frequency identification (RFID) technology is becoming increasingly popular. Identification time is a key performance metric to evaluate the RFID system. The present paper analyzes the deficiencies of the state-of-the-arts algorithms and proposes a novel sub-frame-based algorithm with adaptive frame breaking policy to lower the tag identification time for EPC global C1 Gen2 UHF RFID standard. Through the observation of slot statistics in a sub-frame, the reader estimates the tag quantity and efficiently calculates an optimal frame size to fit the unread tags. Only when the expected average identification time in the calculated frame size is… More >

Shuaiwei Zhang¹, Xiaoyuan Yang^1,*, Weidong Zhong¹, Yujuan Sun²

CMC-Computers, Materials & Continua, Vol.56, No.2, pp. 325-338, 2018, DOI:10.3970/cmc.2018.03611

Abstract As one of the typical method for side channel attack, DPA has become a serious trouble for the security of encryption algorithm implementation. The potential capability of DPA attack induces researchers making a lot of efforts in this area, which significantly improved the attack efficiency of DPA. However, most of these efforts were made based on the hypothesis that the gathered power consumption data from the target device were stable and low noise. If large deviation happens in part of the power consumption data sample, the efficiency of DPA attack will be reduced rapidly. In this work, a highly efficient… More >