Fernando A. Rochinha¹, Rubens Sampaio²

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.2, pp. 7-18, 2000, DOI:10.3970/cmes.2000.001.167

Abstract The dynamics of flexible systems, such as robot manipulators, mechanical chains or cables, is becoming increasingly important in engineering. The main question arising from the numerical modelling of large overall motions of multibody systems is an appropriate treatment for the large rotations. In the present work an alternative approach is proposed leading to a time-stepping numerical algorithm which achieves stable solutions combined with high precision. In particular, in order to check the performance of the proposed approach, two examples having preserved constants of the motion are presented. More >

Mohamed Rady¹, Eric Arquis²

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.2, pp. 137-152, 2010, DOI:10.3970/fdmp.2010.006.137

Abstract In the present article, differential scanning calorimetry (DSC) and a modified T-history method have been used to study the phase changing behavior of granular composites. Further modifications and improvements of the two methods are employed to handle granular materials undergoing phase change over a temperature range. A simple procedure has been advised to obtain accurate results from the DSC measurements based on the estimation of the thermal resistance between the sample and its enclosure. The concept of enthalpy and its relationship with temperature has been employed in the T-history analysis to obtain enthalpy-temperature and apparent heat capacity curves similar to… More >

S. Sabbaghi¹, M. Shariaty-Niassar², Sh. Ayatollahi¹, A. Jahanmiri¹

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.2, pp. 113-124, 2008, DOI:10.3970/fdmp.2008.004.113

Abstract In this study, the Onset of Asphaltene Precipitation is predicted by a modified Virial equation of state. The bases of quantum mechanics and statistical thermodynamics are used to evaluate the potential energy and intermolecular forces related to asphaltene molecules. The Virial equation of state is modified using group-contribution-methods for asphaltenes, which are assumed to be polymeric-like compounds consisting of aggregates of monodisperse asphaltene monomers. It is shown how the modified Virial equation of state with the Peneloux correction leads to estimate the molar volume and solubility parameter. These parameters are also compared successfully with results provided by the Soave-Redlich-Kwong equation… More >

M. Daian¹, A. Taube², G. Torgovnikov³, G. Daian⁴, Y. Shramkov⁵

CMC-Computers, Materials & Continua, Vol.8, No.3, pp. 165-172, 2008, DOI:10.3970/cmc.2008.008.165

Abstract Microwave wood modification and treatment technologies become more and more essential within the wood industry due to their technical and economical advantages. Microwave processing of wood involves many complicated physical phenomena and requires a very careful control of variables (such as intensity of microwave power, loading period, maximum temperature, etc.) in order to reduce structural deformations of the processed wood. To optimise and minimise the project design engineers' work, modelling and simulation of the microwave energy-wood interaction represents an indispensable tool.
This research work has been undertaken with the aim to design and optimise microwave applicators for microwave pre-drying… More >

Heng Cheng Lin^1,2, Chieh Kung³, Rong Sheng Chen²

CMC-Computers, Materials & Continua, Vol.6, No.1, pp. 43-50, 2007, DOI:10.3970/cmc.2007.006.043

Abstract Presented herein are the evaluation results of the BGA solder ball shape using energy method, two types of solder, viz. Sn37Pb and Sn80Pb, are selected .The geometry of the solder bump is firstly estimated using free computer software, the Surface Evolver, an interactive program which is an energy-based approach for the study of liquid droplet surfaces shaped by surface tension and other energies. The solder bump is then numerically constructed in a finite element model that simulates a BGA package. The influences of both upper and bottom solder pad radii, the surface tension on the balls, and the external load… More >

Yu Han^1,*, Wenxian Zheng², Guangjun Wen¹, Chu Chu¹, Jian Su³, Yibo Zhang⁴

CMC-Computers, Materials & Continua, Vol.60, No.2, pp. 795-812, 2019, DOI:10.32604/cmc.2019.05719

Abstract In recent years, Researchers have proposed the concept of Energy Harvesting Backscatter Wireless Networks (EHBWN). EHBWN usually consists of one sink and several backscatter nodes. Backscatter nodes harvest energy from their environment and communicate with sink through backscattering the carrier wave transmitted by sink. Although a certain amount of access protocols for Energy Harvesting Wireless Networks have been present, they usually do not take the sink’s receiver sensitivity into account, which makes those protocols unsuitable in practice. In this paper, we first give an analysis of the backscatter channel link budget and the relationship between the effective communication range and… More >

Mohammed Kaddi^1,3,*, Khelifa Benahmed², Mohammed Omari³

CMC-Computers, Materials & Continua, Vol.58, No.3, pp. 603-624, 2019, DOI:10.32604/cmc.2019.05341

Abstract Wireless Sensor Networks (WSNs) have hardware and software limitations and are deployed in hostile environments. The problem of energy consumption in WSNs has become a very important axis of research. To obtain good performance in terms of the network lifetime, several routing protocols have been proposed in the literature. Hierarchical routing is considered to be the most favorable approach in terms of energy efficiency. It is based on the concept parent-child hierarchy where the child nodes forward their messages to their parent, and then the parent node forwards them, directly or via other parent nodes, to the base station (sink).… More >

Gang Xu^1,*, Yufan Zhu¹, Lishan Deng¹, Guozhao Wang², Bojian Li¹, Kin-chuen Hui³

CMC-Computers, Materials & Continua, Vol.58, No.3, pp. 879-892, 2019, DOI:10.32604/cmc.2019.03752

Abstract In this paper, we propose an efficient method to construct energy-minimizing B-spline curves by using discrete mask method. The linear relations between control points are firstly derived for different energy-minimization problems, then the construction of B-spline curve with minimal internal energy can be addressed by solving a sparse linear system. The existence and uniqueness of the solution for the linear system are also proved. Experimental results show the efficiency of the proposed approach, and its application in G¹ blending curve construction is also presented. More >

Yugai Huang ^{1, 2, *}

CMC-Computers, Materials & Continua, Vol.57, No.3, pp. 485-494, 2018, DOI:10.32604/cmc.2018.03112

Abstract It has been demonstrated that low energy electrons (LEEs) can induce serious DNA damages including bases loss and even single and double strand breaks. Experiments also showed that LEE induced DNA damages will be reduced with the presence of amino acids. For understanding of the protection of amino acids to DNA, the stability of 6 kinds of thymine and glycine (T-g) dimers with planar configurations with an excess electron were studied with density functional theory (DFT) method. The results show that, when the excess electron is vertically attached, all the dimers become more active with higher energy. After re-optimization, 4… More >

Xiaodong Liu¹, Qi Liu^1,*

CMC-Computers, Materials & Continua, Vol.57, No.2, pp. 179-194, 2018, DOI:10.32604/cmc.2018.04025

Abstract In a home energy management system (HEMS), appliances are becoming diversified and intelligent, so that certain simple maintenance work can be completed by appliances themselves. During the measurement, collection and transmission of electricity load data in a HEMS sensor network, however, problems can be caused on the data due to faulty sensing processes and/or lost links, etc. In order to ensure the quality of retrieved load data, different solutions have been presented, but suffered from low recognition rates and high complexity. In this paper, a validation and repair method is presented to detect potential failures and errors in a domestic… More >