Girika Jyoshna^1,*, Md. Zia Ur Rahman¹, L. Koteswararao²

CMC-Computers, Materials & Continua, Vol.70, No.2, pp. 3067-3080, 2022, DOI:10.32604/cmc.2022.020160

Abstract In issues like hearing impairment, speech therapy and hearing aids play a major role in reducing the impairment. Removal of noise signals from speech signals is a key task in hearing aids as well as in speech therapy. During the transmission of speech signals, several noise components contaminate the actual speech components. This paper addresses a new adaptive speech enhancement (ASE) method based on a modified version of singular spectrum analysis (MSSA). The MSSA generates a reference signal for ASE and makes the ASE is free from feeding reference component. The MSSA adopts three key steps for generating the reference… More >

Xiuyun Chen¹, Xiaomeng Yin², Kunpeng Li³, Ruhui Cheng¹, Yanming Xu^1,4,*, Wei Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.1, pp. 323-339, 2021, DOI:10.32604/cmes.2021.016794

Abstract The present work couples isogeometric analysis (IGA) and boundary element methods (BEM) for three dimensional steady heat conduction problems with variable coefficients. The Computer-Aided Design (CAD) geometries are built by subdivision surfaces, and meantime the basis functions of subdivision surfaces are employed to discretize the boundary integral equations for heat conduction analysis. Moreover, the radial integration method is adopted to transform the additional domain integrals caused by variable coefficients to the boundary integrals. Several numerical examples are provided to demonstrate the correctness and advantages of the proposed algorithm in the integration of CAD and numerical analysis. More >

Mohd Ahmed^1,*, Devender Singh², Saeed Al Qadhi¹, Nguyen Viet Thanh³

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.1, pp. 167-189, 2021, DOI:10.32604/cmes.2021.014672

Abstract The performance of a-posteriori error methodology based on moving least squares (MLS) interpolation is explored in this paper by varying the finite element error recovery parameters, namely recovery points and field variable derivatives recovery. The MLS interpolation based recovery technique uses the weighted least squares method on top of the finite element method's field variable derivatives solution to build a continuous field variable derivatives approximation. The boundary of the node support (mesh free patch of influenced nodes within a determined distance) is taken as circular, i.e., circular support domain constructed using radial weights is considered. The field variable derivatives (stress… More >

Baoshou Liu^1,2, Xiaolei Yan¹, Yangfan Li³, Shiwei Zhou⁴, Xiaodong Huang^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.2, pp. 523-540, 2021, DOI:10.32604/cmes.2021.017211

Abstract This paper proposes a new element-based multi-material topology optimization algorithm using a single variable for minimizing compliance subject to a mass constraint. A single variable based on the normalized elemental density is used to overcome the occurrence of meaningless design variables and save computational cost. Different from the traditional material penalization scheme, the algorithm is established on the ordered ersatz material model, which linearly interpolates Young's modulus for relaxed design variables. To achieve a multi-material design, the multiple floating projection constraints are adopted to gradually push elemental design variables to multiple discrete values. For the convergent element-based solution, the multiple… More >

Jesus Hamilton Ortiz¹, Javier Ferney Castillo García², Osamah Ibrahim Khalaf³, Fernando Velez Varela^2,*, Pedro Jefferson Barragan Baron², Jhon Hadder Guzmán Atehortúa²

Journal on Internet of Things, Vol.3, No.2, pp. 53-63, 2021, DOI:10.32604/jiot.2021.014736

Abstract This work shows the development of a module that performs measurements of electrical variables in a low voltage power transformer. These variables are sent by means of the IEEE802.11 standard, connecting to a database stored in the cloud; associating with the meter IoT concepts, this to allow a client to perform an analysis, monitoring and management of their electrical network. For the construction of this module, non-invasive current sensors connected to a three-phase meter are used and a communication card is used that allows data to be extracted from the meter and sent to the cloud database. This module, to… More >

Shufang Song^1,*, Ruyang He¹, Zhaoyin Shi¹, Weiya Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 65-85, 2021, DOI:10.32604/cmes.2021.015378

Abstract The variable importance measure (VIM) can be implemented to rank or select important variables, which can effectively reduce the variable dimension and shorten the computational time. Random forest (RF) is an ensemble learning method by constructing multiple decision trees. In order to improve the prediction accuracy of random forest, advanced random forest is presented by using Kriging models as the models of leaf nodes in all the decision trees. Referring to the Mean Decrease Accuracy (MDA) index based on Out-of-Bag (OOB) data, the single variable, group variables and correlated variables importance measures are proposed to establish a complete VIM system… More >

Jian Yang, Xiaoli Li^*, Hui Wang, Kaiqiang Geng

Journal of Renewable Materials, Vol.9, No.12, pp. 2241-2260, 2021, DOI:10.32604/jrm.2021.015565

Abstract In the present study, in order to investigate the effects of fly ash on the structural evolution and strength damage mechanism of Pisha-sandstone cement soil, unconfined compressive strength tests of Pisha-sandstone cement soil with different fly ash content levels and various ages were carried out. The apparent morphology, microstructures, and chemical compositions of the samples were observed and analyzed using ultra-depth three-dimensional microscopy, scanning electron microscopy, and XRD methods. The results revealed that the unconfined compressive strength levels of Pisha-sandstone cement soil samples displayed increasing trends with the increases in fly ash content and age. For example, when the fly… More > Graphic Abstract

Bin Xu^1,2,3,*, Jianming Zhu¹, Junzhe Wen¹, Shanshan Lin¹, Yunkai Zhao¹, Jin Qi^1,2, Yu Xue⁴, Sichong Qin⁵

Intelligent Automation & Soft Computing, Vol.29, No.2, pp. 525-537, 2021, DOI:10.32604/iasc.2021.018338

Abstract The optimization of wind farm layouts is very important for the effective utilization of wind resources. A fixed wind turbine hub height in the layout of wind farms leads to a low wind energy utilization and a higher LCOE (levelized cost of electricity). WOMH (Wind Farm Layout Optimization Model Considering Multiple Hub Heights) is proposed in this paper to tackle the above problem. This model is different from the traditional fixed hub height model, as it uses a variable height wind turbine. In WOMH, the Jensen wake and Weibull distribution are used to describe the wake effect on the wind… More >

Abdelatif Oussar^1,*, Abdelmoumen Ferrag¹, Mohamed Guiatni¹, Mustapha Hamerlain²

Intelligent Automation & Soft Computing, Vol.29, No.2, pp. 467-495, 2021, DOI:10.32604/iasc.2021.01000

Abstract This paper presents the design of a robust architecture for the tracking of an unmanned ground vehicle (UGV) by an unmanned aerial vehicle (UAV). To enhance the robustness of the ground vehicle in the face of external disturbances and handle the non-linearities due to inputs saturation, an integral sliding mode controller was designed for the task of trajectory tracking. Stabilization of the aerial vehicle is achieved using an integral-backstepping solution. Estimation of the relative position between the two agents was solved using two approaches: the first solution (optimal) is based on a Kalman filter (KF) the second solution (robust) uses… More >

Khaldoon M. Alhyasat^1,*, Kamarulzaman Ibrahim¹, Amer Al-Omari², Mohd Aftar Abu Bakar¹

Computer Systems Science and Engineering, Vol.39, No.1, pp. 55-67, 2021, DOI:10.32604/csse.2021.014909

Abstract In this paper, the Rama distribution (RD) is considered, and a new model called extended Rama distribution (ERD) is suggested. The new model involves the sum of two independent Rama distributed random variables. The probability density function (pdf) and cumulative distribution function (cdf) are obtained and analyzed. It is found that the new model is skewed to the right. Several mathematical and statistical properties are derived and proved. The properties studied include moments, coefficient of variation, coefficient of skewness, coefficient of kurtosis and moment generating function. Some simulations are undertaken to illustrate the behavior of these properties. In addition, the… More >