Differential Game for Distributed Power Control in Device-to-Device Communications Underlaying Cellular Networks

Wireless Personal Communications - In the formulating of power control for wireless networks, the radio channel is commonly formulated using static models of optimization or game theory. In these...     

Improvement in hydrolytic procedure for GLC determination of non-indolyl glucosinolates in rapeseed as isothiocyanates

Some methods determine the non-indolyl glucosinolates content in rapeseed as their hydrolysates: the isothiocyanates and the oxazolidinethiones. These methods in their present form underestimate the amount of the glucosinolates content. In this investigation, a modified method was developed to give a better quantitative estimate, indicating a glucosinolate level five times that obtained by a typical existing method.     

Evaluation of a proper controller performance for maximum-power point tracking of a stand-alone PV system

In this paper the implementation of a suggested stand-alone PV system, for maximum-power point tracking (MPPT), is carried out. Also, this paper presents a comparative study, through experimental work, between the conventional PI controller and the fuzzy logic controller (FLC) under different atmospheric conditions. The implemented system with both the PI controller and the FLC gives a good maximum-power operation of the PV array, but the tracking capability for different optimum operating points is better and faster for the case of using the FLC compared to the case of using the PI controller.     

Thickness-dependence of stoichiometry and microstructure characteristics in correlation with conductivity type of CdTe films

CdTe films were prepared by physical vapour deposition on a substrate at room temperature (RT) as well as on a cold (LT) one using low deposition rate. The thickness-dependence of stoichiometry revealed an abrupt decrease in the Cd/Te ratio as the thickness increases. Change of thickness did not affect the type of observed (111) crystallographic texture, only the degree of preferred orientation is enhanced as the film grows. The internal strain was negligible while the crystallite size increased rapidly at small thickness (up to 400 nm), and less thickness dependence was observed with further film growth. However, thickness dependence of lattice parameters showed a minimum and a maximum at approximately 300 nm in the case of RT and LT, respectively. The observed change in conductivity from n- to p-type and its vital correlation with the stoichiometry and structural characteristics were presented. Based on thickness dependence of stoichiometry and lattice parameters as well as the conductivity type, formation and annihilation of lattice defects were considered.     

Modelling and controller design of an isolated diesel enginepermanent magnet synchronous generator

A method to analyze the steady-state performance of a stand-alone permanent magnet synchronous generator driven by a diesel engine is presented. The proposed method is based on equivalent d-q circuits and the phasor diagram of such a generator under steady-state conditions. A fixed capacitor-thyristor controlled reactor scheme is used to regulate the generator terminal voltage by controlling the thyristor ignition angle. Furthermore the overall system dynamics are modelled in terms of state variables and control inputs. Based on a reduced order linearized model, digital optimal state and output feedback controllers are designed by minimising a quadratic performance index using the dynamic programming technique. The objective of the controller is to maintain the load voltage and frequency constant under varying load conditions. The controller's effectiveness is assessed by examining the closed-loop system response to sudden load changes     

On an evolutionary approach for constrained optimization problem solving

Over the last few decades, many different evolutionary algorithms have been introduced for solving constrained optimization problems. However, due to the variability of problem characteristics, no single algorithm performs consistently over a range of problems. In this paper, instead of introducing another such algorithm, we propose an evolutionary framework that utilizes existing knowledge to make logical changes for better performance. The algorithmic aspects considered here are: the way of using search operators, dealing with feasibility, setting parameters, and refining solutions. The combined impact of such modifications is significant as has been shown by solving two sets of test problems: (i) a set of 24 test problems that were used for the CEC2006 constrained optimization competition and (ii) a second set of 36 test instances introduced for the CEC2010 constrained optimization competition. The results demonstrate that the proposed algorithm shows better performance in comparison to the state-of-the-art algorithms.     

Fuzzy-based hunger games search algorithm for global optimization and feature selection using medical data

Neural Computing and Applications - Feature selection (FS) is one of the basic data preprocessing steps in data mining and machine learning. It is used to reduce feature size and increase model...     

Effect of electron irradiation on alternating current electrical properties of gelatin – cadmium sulfide nano-composite films

Gelatin was doped with 1 %, 3 %, 5 % and 10 % cadmium sulfide nanoparticles in weight concentrations forming the gelatin-cadmium sulfide nanocomposites and irradiated by various electron beam doses equals 50 kGy, 75 kGy, 100 kGy, and 150 kGy using 3 MeV – 3 mA electron accelerator. The applied alternating current electrical field frequency ranging from 70 Hz to 5 MHz is what caused the fluctuation in dielectric properties and alternating current electrical conductivity of these nanocomposites. The results showed that the films of 1 %, 3 %, 5 %, and 10 % for blank (nanocomposite film without electron beam irradiation) nanocomposites had the highest dielectric parameters (έ, ϵ′′, tan δ) at 0.5 kHz with values of (0.696, 0.0233, 0.034), (0.533, 0.0114, 0.0215), (0.402, 0.001196, 0.003), and (0.459, 0.00418, 0.0091), respectively. However, the lowest dielectric parameters were (0.645, 0.00618, 0.0066), (0.523, 0.00165, 0.0215), (0.417, 0.00035, 0.0008), and (0.455, 0.00066, 0.0015) at 5 MHz, respectively. The highest conductivity values for blank nanocomposites of 1 %, 3 %, 5 %, and 10 % were 1.79×10⁻⁴ S/m, 1.45×10⁻⁴ S/m, 1.16×10⁻⁴ S/m, 1.27×10⁻⁴ S/m at 5 MHz, and the lowest values were 1.92×10⁻⁸ S/m, 1.49×10⁻⁸ S/m, 1.13×10⁻⁸ S/m, 1.26×10⁻⁸ S/m at 0.5 kHz, respectively. For irradiated nanocomposites at 5 MHz, the dielectric constant order for 1 % was 100 kGy, 150 kGy, 50 kGy, and 75 kGy with values 0.63, 0.537, 0.532, and 0.523, respectively. For 10 % weight concentration, the order was 50 kGy, 100 kGy, 150 kGy, and 75 kGy with values 0.515, 0.477, 0.47, and 0.437, respectively. Otherwise the dielectric constant order for 3 % and 5 % was 100 kGy, 75 kGy, 150 kGy, and 50 kGy. The highest dielectric properties and conductivity values for blank and irradiated nanocomposites were observed at 100 kGy for 1 %, 3 %, and 5 %.     

A new expert system for learning management systems evaluation based on neutrosophic sets

There has been a sudden increase in the usage of Learning Management Systems applications to support learner's learning process in higher education. Many studies in learning management system evaluation are implemented under complete information, while the real environment has uncertainty aspects. As these systems were described by development organizations with uncertainty terms such as vague, imprecise, ambiguity and inconsistent, that is why traditional evaluation methods may not be effective. This paper suggests neutrosophic logic as a better option to simulate human thinking than fuzzy logic because unlike fuzzy logic, it is able to handle indeterminacy of information which expresses the percentage of unknown parameters. As previous studies suggested neutrosophic decision maker and neutrosophic expert systems as future work in ecommerce and e‐learning applications, this paper presents neutrosphic expert system for learning management systems evaluation. Information for building and validating the neutrosophic expert system is collected from five experts using surveys, and then analysis is done by using Fuzzytech 5.54d software. Finally, the comparison between fuzzy expert system and neutrosophic expert system results show that the neutrosophic logic is capable of representing uncertainty in human thinking for evaluating Learning Management Systems.