Output Linearization of Single-Input Single-Output Fuzzy System to Improve Accuracy and Performance

For fuzzy systems to be implemented effectively, the fuzzy membership function (MF) is essential. A fuzzy system (FS) that implements precise input and output MFs is presented to enhance the performance and accuracy of single-input single-output (SISO) FSs and introduce the most applicable input and output MFs protocol to linearize the fuzzy system’s output. Utilizing a variety of non-linear techniques, a SISO FS is simulated. The results of FS experiments conducted in comparable conditions are then compared. The simulated results and the results of the experimental setup agree fairly well. The findings of the suggested model demonstrate that the relative error is abated to a sufficient range (≤ ± 10%) and that the mean absolute percentage error (MPAE) is reduced by around 66.2%. The proposed strategy to reduce MAPE using an FS improves the system’s performance and control accuracy. By using the best input and output MFs protocol, the energy and financial efficiency of every SISO FS can be improved with very little tuning of MFs. The proposed fuzzy system performed far better than other modern days approaches available in the literature.     

Backstepping and Synergetic Controllers for the Chemotherapy of Brain Tumor

International Journal of Control, Automation and Systems - The treatment of brain tumors by chemotherapy through the controlled rate of drug has been a challenging task since long. Two nonlinear...     

A New Energy-Aware Cluster Head Selection Algorithm for Wireless Sensor Networks

Wireless Personal Communications - Wireless Sensor Networks (WSN) always need energy due to the areas they are used. The use of sensors is quite wide, and in some of the places, it is very...     

Flexible papers derived from polypyrrole deposited cellulose nanofibers for enhanced electromagnetic interference shielding in gigahertz frequencies

An array of highly conductive, lightweight and flexible cellulose nanopapers as effective attenuators of electromagnetic radiations within 8.2–12.4 GHz (X band) were formulated via in situ polymerization of pyrrole monomers on to cellulose nanofibers (CNFs). It is quite obvious that the free hydroxyl groups on the surface of CNFs facilitate the formation of intense intermolecular hydrogen bonding with PPy which is envisaged for its excellent electromagnetic shielding performance with an average shielding effectiveness of ca. –22 dB (>99% attenuation) at 8.2 GHz for a paper having 1 mm thickness. The fabricated papers displayed a predominant absorption mechanism (ca. 89%) rather than reflection (ca. 11%) for efficiently attenuating electromagnetic radiations, which has a considerable importance in the modern telecommunication sector. Thus, the designed PPy/CNF papers would replace the conventional metal-based shields and pave way for the development of green microwave attenuators functioning via a strong absorption mechanism. The PPy/CNF nanopapers exhibited a DC conductivity of 0.21 S/cm, a prime requisite for the development of highly efficient electromagnetic shields. Undoubtedly, such nanopapers can be employed in wide range of applications such as electrodes for supercapacitors and other freestanding flexible paper-based devices.     

Anomalous Behavior of 2D Janus Excitonic Layers under Extreme Pressures

Newly discovered 2D Janus transition metal dichalcogenides layers have gained much attention from a theory perspective owing to their unique atomic structure and exotic materials properties, but little to no experimental data are available on these materials. Here, experimental and theoretical studies establish the vibrational and optical behavior of 2D Janus S–W–Se and S–Mo–Se monolayers under high pressures for the first time. Chemical vapor deposition (CVD)-grown classical transition metal dichalcogenides (TMD) monolayers are first transferred onto van der Waals (vdW) mica substrates and converted to 2D Janus sheets by surface plasma technique, and then integrated into a 500 µm size diamond anvil cell for high-pressure studies. The results show that 2D Janus layers do not undergo phase transition up to 15 GPa, and in this pressure regime, their vibrational modes exhibit a nonmonotonic response to the applied pressures (dω/dP). Interestingly, these 2D Janus monolayers exhibit unique blueshift in photoluminescence (PL) upon compression, which is in contrast to many other traditional semiconductor materials. Overall theoretical simulations offer in-depth insights and reveal that the overall optical response is a result of competition between the ab-plane (blueshift) and c-axis (redshift) compression. The overall findings shed the very first light on how 2D Janus monolayers respond under extreme pressures and expand the fundamental understanding of these materials.     

Immobilization of phenol in cement-based solidified/stabilized hazardous wastes using regenerated activated carbon: role of carbon

The use of regenerated activated carbon as an immobilizing additive for phenol in solidification/stabilization (S/S) processes was investigated. The adsorption capacity of regenerated carbon was compared to that of the virgin form and was found to be very close. The effects of pH and Ca(OH)₂ concentration within the S/S monolith on the adsorption process were also examined. Kinetic tests were performed to evaluate the adsorption of phenol on different forms of F400 carbon, including the regenerated form. Kinetic tests were performed in aqueous solutions as well as in liquid–sand mixtures. In both cases, it was found that phenol adsorption on F400 carbon was fairly fast. More than 60% of the equilibrium adsorption amount could be achieved within the first hour for aqueous solutions. For sand-solution kinetics, it was found that 1% carbon (based on dry sand weight) was capable of achieving more than 95% removal of the initial amount of phenol present in solution (1000 and 5000 ppm). Fourier transform infrared (FT-IR) spectroscopy and X-ray mapping tests indicated a homogenous mixing of the carbon into the cement matrix. The carbon was also found to enhance the hydration of cement, which was retarded by the existence of phenol.     

Correction to: Deposition of bismuth sulfide and aluminum doped bismuth sulfide thin films for photovoltaic applications

Journal of Materials Science: Materials in Electronics -     

Investigation of factors affecting dynamic modulus and phase angle of various asphalt concrete mixtures

This study investigated the dynamic response of various asphalt concrete (AC) mixtures subjected to sinusoidal loading. Eight AC mixtures (four wearing and four base course) were selected including (but not limited to): superpave, asphalt institute manual series, and dense bituminous macadam. The uniaxial dynamic modulus (|E*|) test at various temperatures (4.4–54.4 °C) and frequencies (0.1–25 Hz) was conducted using asphalt mixture performance tester. Statistical analysis of two-level factorial was employed to regulate the factors affecting the AC mixtures. The results revealed that an increase in temperature (from 21.1 to 37.8 °C), translated into 45 and 43 % drop in |E*| values on average while 80 and 67 % decrease in |E*| values was attributed to the sweep of frequency (from 25 to 0.1 Hz) for wearing and base course mixes, respectively. Non-linear regression model was developed to express the dynamic modulus as a function of test temperature, loading frequency and mixture volumetric parameter. Furthermore, Witczak model of dynamic modulus prediction was evaluated and the results indicated a close fit with an average under prediction error of 0.20. The study characterized and ranked the representative AC mixtures that could help in selecting the material/gradation for mechanistic-empirical pavement design approach.     

An efficient Dynamic Addressing based routing protocol for Underwater Wireless Sensor Networks

Underwater Wireless Sensor Networks (UWSNs) are different in many aspects as compared to terrestrial sensor networks. Other than long propagation delays and high error probability, continuous node movement makes it hard to manage the location information of sensor nodes. Determining the location of every node is a major issue as nodes can move continuously with the water currents. In order to handle the problem of large propagation delays and unreliable link quality, many algorithms have been proposed and some of them provide good solutions for these issues, but continuous node movements still need attention. In order to handle the problem of node mobility, we proposed a Hop-by-Hop Dynamic Addressing Based (H2-DAB) routing protocol, where every node in the network will be assigned a routable address in a quick and efficient way without requiring an explicit configuration or any dimensional location information. It helps to provide an option where nodes can communicate without any centralized infrastructure, also a mechanism is available where nodes can come and leave the network without having any serious effect on the rest of the network. Simulation results show that H2-DAB can manage easily during the quick routing changes where node movements are very frequent yet require little or no overhead in order to complete its tasks.