Applying gravitational search algorithm in the QoS-based Web service selection problem

With the growing use of service-oriented architecture for designing next generation software systems,the service composition problem and its execution complexity have become even more important in resp...     

A self-routing load balancing algorithm in parallel computing: comparison to the central algorithm

Load balancing is an important stage of a system using parallel computing where the aim is the balance of workload among all processors of the system. In this paper, we introduce a new load balancing algorithm with new capabilities for parallel systems, among which is the independence of a separate route-finder algorithm between the load receiver and sender nodes. In addition to simulation of the new algorithm, due to similarity in behavior to the proposed algorithm, the central algorithm is simulated. Simulation results show that, the system performance increases with the increase of the degree of neighborhood between the processors. These results also indicate the algorithm’s high compatibility with environment changes.     

Electronic and magnetic properties of Cd-doped zigzag AlN nanoribbons from first principles

The effect of Cd impurity on the electronic structure and magnetic properties of hydrogen-terminated AlN nanoribbons with zigzag edges (ZAlNNRs) was investigate using the band structure results obtained through the full potential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT). The exchange correlation potential was treated by the generalized gradient approximation within the Perdew scheme. The calculated results show that the H-terminated zigzag AlN nanoribbon is semiconducting and nonmagnetic material with a direct band gap of about 2.78 eV, while the Cd-doped H-terminated ZAlNNR structures show complete (100 %) spin polarization very close to the Fermi level, which will result in spin-anisotropic transport. The charge transport is totally dominated by Cd spin down electrons in the H-terminated ZAlNNR. These results suggest potential applications for the development of using the AlN nanoribbons in nanoelectronics and magnetoelectronic devices as a base.     

A new quantum-dot cellular automata full-adder

A novel expandable five-input majority gate for quantum-dot cellular automata and a new full-adder cell are presented. Quantum-dot cellular automata (QCA) is an emerging technology and a possible alternative for semiconductor transistor based technologies. A novel QCA majority-logic gate is proposed. This component is suitable for designing QCA circuits. The gate is simple in structure and powerful in terms of implementing digital functions. By applying these kinds of gates, the hardware requirement for a QCA design can be reduced and circuits can be simpler in level, gate counts and clock phases. In order to verify the functionality of the proposed device, some physical proofs are provided. The proper functionality of the FA is checked by means of computer simulations using QCADesigner tool. Both simulation results and physical relations confirm our claims and its usefulness in designing every digital circuit.     

Effects of Raw Material Molar Ratio and Addition of Mg on Titanium Aluminide–Alumina Composite Formation Mechanism

Powder Metallurgy and Metal Ceramics - In this study, the effects of molar ratio of the raw materials (TiO2 and Al) and the addition of Mg on the titanium aluminide–alumina composite...     

Preparation,morphology and conductivity of polyacrylonitrile/multi-wall carbon nanotubes composite nanofibers

Composite nanofibers of polyacrylonitrile/multi-wall carbon nanotubes (PAN/MWCNTs) were prepared via electrospinning. Samples contained 0, 0.5, 1, 2, 3, and 3.5 wt% of MWCNTs. The viscosity and electrical conductivity of electrospinning solutions were measured. Results revealed that, with the addition of multi-wall carbon nanotubes, viscosity was increased and electrical conductivity was improved. Rheological behavior was studied using two different viscometers. Moreover, morphology and diameters of the composite nanofibers were studied by scanning electron microscopy (SEM) and nanofiber diameter distributions were presented. SEM micrographs showed that by adding MWCNTs, the average diameter of nanofibers was increased. Furthermore, the effect of MWCNTs on glass transition temperature, T _g, was investigated using differential scanning calorimetry (DSC) technique. The results showed that T _g was increased with the addition of MWCNTs. In addition, Fourier transform infrared spectroscopy (FTIR) results showed that MWCNTs can affect the orientation ability of polymer chains. The effects of adding salt, increasing voltage and changing the tip-to-collector distance on the morphology and diameters of composite nanofibers were examined. The electrical conductivity results of electrospun mats were measured by a two-probe method. Electrical conductivity was increased by addition of MWCNTs and its behavior followed the percolation theory. Finally, it was observed that mats with smaller diameters have higher electrical conductivity.     

Video-based isolated hand sign language recognition using a deep cascaded model

In this paper, we propose an efficient cascaded model for sign language recognition taking benefit from spatio-temporal hand-based information using deep learning approaches, especially Single Shot Detector (SSD), Convolutional Neural Network (CNN), and Long Short Term Memory (LSTM), from videos. Our simple yet efficient and accurate model includes two main parts: hand detection and sign recognition. Three types of spatial features, including hand features, Extra Spatial Hand Relation (ESHR) features, and Hand Pose (HP) features, have been fused in the model to feed to LSTM for temporal features extraction. We train SSD model for hand detection using some videos collected from five online sign dictionaries. Our model is evaluated on our proposed dataset (Rastgoo et al., Expert Syst Appl 150: 113336, 2020), including 10’000 sign videos for 100 Persian sign using 10 contributors in 10 different backgrounds, and isoGD dataset. Using the 5-fold cross-validation method, our model outperforms state-of-the-art alternatives in sign language recognition

     

A bi-objective mixed-model assembly line sequencing problem considering customer satisfaction and customer buying behaviour

Customer satisfaction and focusing on the most profitable customers are the key elements to achieving a sustainable competitive advantage in the current business environment. The mixed-model assembly line (MMAL) is an efficient type of manufacturing system that has been used increasingly over recent years to satisfy diverse customer demands. Product sequencing in an MMAL system has a huge effect on the performance of the firm in meeting customer demand and, therefore, on customer satisfaction. This study aims to address a sequencing problem with respect to recency, frequency and monetary factors. A two-stage framework is developed to achieve this goal. First, the prioritized orders based on the preference ranking organization method for enrichment of evaluations (PROMETHEE) are categorized into high-priority and normal-priority orders. Then, a bi-objective mathematical programming model is developed to determine the optimum sequence of products to minimize the total cost, as well as to maximize levels of customer satisfaction. After validation of the proposed model, owing to the NP-hard nature of this problem, two multi-objective metaheuristics are applied to tackle the second stage of this study. Several test problems are presented to evaluate the performance of these algorithms. The results show the superiority of one solution approach over the other.     

Electrochemical pseudocapacitors of different compounds and nanocomposite of manganese: an introduction and review to it in recent studies

Journal of Materials Science: Materials in Electronics - This review gives an overview of the synthesis, surface, and electrochemical investigations over Mn-based compounds in the development of...