Showing papers by "Graduate University of Advanced Technology published in 2022"

Connectivity and Coverage Constrained Wireless Sensor Nodes Deployment Using Steepest Descent and Genetic Algorithms

Abstract: Connectivity and different coverage types including target, area, and barrier coverages are among the most critical challenges of wireless sensor networks (WSN). This paper investigates node deployment for the challenges of target coverage, area coverage, and connectivity over randomly distributed homogeneous and heterogeneous WSNs, and suggests a new method in both centralized and distributed modes which (i) covers all targets by the required number of sensors, (ii) provides maximum area coverage and connectivity over the network, and (iii) manages sensors' movement from the initial locations to the final ones. Specifically, in the case of target coverage, a new analytical deployment method using the steepest descend (SD) algorithm with Armijo and Wolf rules is proposed instead of evolutionary methods. The results demonstrate this method outperforms over Genetic algorithm (GA) in managing sensors' movement towards targets, guaranteeing 100% coverage in targets, and providing a significant reduction- more than 40% in the worst condition-in algorithm complexity. However, when area coverage and connectivity are also considered, a new hybrid deployment method, which first uses GA to extract the optimal sensors' coordinates via analyzing these challenges simultaneously and then employs SD algorithm to move sensors towards these locations, is suggested. Numerical results confirm the complexity of this two-step method is approximately identical to the GA method of existing research; however, it provides sensors' trajectory and more accuracy for network coverage and connectivity.

Applications of Non‐precious Transition Metal Oxide Nanoparticles in Electrochemistry

Abstract: Non-precious transition metal oxide nanomaterials offer numerous opportunities for various cost-effective electrochemical applications. This review article features the design and advancement of such nanomaterials with unique features applied for the fabrication of electrochemical devices. Also, it discusses various new syntheses of transition metal oxide nanoparticles (TMO NPs) via multiple chemicophysical and biological procedures. Further, the novel appliances of the TMO NPs with varying sizes and morphologies are appraised. The advantages and challenges of a number of investigations on the TMO NPs towards electrochemical applications are addressed with their standpoint of cost-effectiveness, applicability, and the efficiency of the introduced nanostructures for the industrial applications.

Application of Conductive Polymer Nanocomposites

Abstract: Conductive polymers (CPs) have been of interest to researchers because of their respective good benefits compared to conventional materials. Their advantages include a wider and adjustable electrical conductivity, a simplified production method, a higher mechanical stability, their general affordability, their lighter weight compared to other materials, and their simple processing. In comparison to the bulk CPs, nanostructured CPs enjoy greater electrical conductivity, larger surface areas, and better electrochemical activities, making them proper materials for multiple uses. Moreover, hybridization between CPs and other nanomaterials allows researchers to obtain attractive functional nanocomposites. Therefore, CP nanocomposites and their benefits have been quickly developed to meet recent demands in analytical uses. As a result, this chapter will address several possible uses of CP-based nanocomposites in energy storage and conversion instrumentation, sensors and biosensors.

Preparation, characterizations and investigation of properties of new poly(ether-imide) nanocomposite films reinforced with zinc oxide nanoparticles

Abstract: This research deals with fabrication and evaluation of properties of poly(ether-imide)/functionalized zinc oxide nanocomposites (PEI/f-ZnO NCs) via an in-situ polymerization method. The process involves the dispersion of pre-functionalized zinc oxide nanoparticles (f-ZnO NPs) in N,N-dimethylacetamide, polycondensation of 5-(2-benzoxazole)-1,3-bis(4-aminophenoxy)benzene (DABO) and pyromellitic dianhydride (PMDA) in the presence of f-ZnO NPs suspension to form poly(amic acid) (PAA), and followed by the thermal imidization of PAA/f-ZnO nanocomposites. For increasing reactivity and compatibility between the nano-fillers and polymer matrix, the periphery of ZnO NPs was amine-functionalized with 3‐aminopropyltriethoxysilane (APS) to form f-ZnO NPs. The structure, morphology, and thermal properties of nanocomposite films with various f-ZnO NPs loadings were systematically characterized using FTIR spectroscopy, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The results indicated that f-ZnO NPs were dispersed uniformly at a nanometer scale in PEI matrix. Owing to such nanodispersion of nanoparticles, the PEI/f-ZnO nanocomposite films exhibit dramatic improvements on thermal stability as compared with the neat polymer.

Mass transfer enhancement in solar stills by nanofluids

Abstract: Nanofluids can play a significant role in mass and heat transfer in solar water treatment systems. Although so far it may not be possible to find a direct relationship between mass transfer and the nanofluids in the technical literature in this regard, the effect of significant interactions between various parameters, especially transfer phenomena in a solar still, explains the prominent role of nanofluids in facilitating the increased transfer phenomena. In this chapter it is proved that the production capability of a solar still can be increased more than 100% with the help of nanofluids, provided that other operational and design parameters are selected correctly. Also, it is shown that by increasing the vapor pressure of the liquid–vapor interface due to the enhancement of heat transfer with nanofluids, the volumetric mass transfer significantly increases, which means an improved evaporation rate and ultimately enhanced production capacity of the solar treatment unit. This shows the important connection between the transfer phenomena in such a system. The points made in this chapter may be the keys to further research.

Modified Plate Frame Interaction method for evaluation of steel plate shear walls with beam-connected web plates

Abstract: Steel plate shear walls with beam-connected web plates (B-SPSW) are considered effective configurations in alleviating the tension field effects on vertical boundary elements through the detachment of web plates from them. It is critical to establish robust analytical models while investigating these setups. The plate-frame interaction approach (PFI), initially introduced for traditional SPSWs, is a widely used model that separately analyses the web plate and the surrounding frame. The purpose of this study was to propose a modified PFI (MPFI) method for B-SPSWs in light of their unique properties. Additionally, the buckling phenomena were thoroughly explored to justify thicker plates in the aforesaid configurations. Finite element models were created to determine the accuracy of the newly generated MPFI method equations for B-SPSWs. The numerical specimens were chosen to illustrate a variety of practical uses for these systems. Finally, the MPFI accurately predicted the strength and stiffness of the case studies, and significant overlaps between the MPFI diagrams and the numerical backbone curves were detected. The ratio of MPFI shear capacity to shear yield strength was found to be between 0.93 and 1.04 in numerical specimens. However, it was determined that the use of large infill plates resulted in the premature production of plastic hinges in the frame, hence reducing the shear capacity envisaged.

Seismic Loss Estimation Using Experimental Fragility and Vulnerability Functions: Case Study of Buzau County, Romania

Abstract: This paper is focused on the seismic risk assessment of Buzau County in Romania. This county overlays the most active seismic source in the region, namely, the Vrancea intermediate-depth se...

Scientific Perspectives to Earthquake Resistant Design of RC Buildings—A Global Approach

Abstract: Earthquakes are the concerned actions for which basic science and mathematics have contributed to form scientific principles for the structural design of built infrastructure. The seismic micro-zonation for hazard estimation generates the demand level for design. Element level damages and testing suggest the stress–strain relationships relevant to behavior and performance estimates. Chord rotation limits define the performance of individual elements in a building as suggested by ASCE-41, TEC07 and EC8. However, curvature limits are a better indicator of ductility and performance in the system. Plastic deformations at the structure level give the overall picture of planning a building structure and overall performance under multiple events. The risk to a particular level of an earthquake depends on the design methods, detailing and cost implications. Thus, design resiliency is an important aspect of mitigating earthquake hazards. The design principles that bring resilience to buildings are evaluated for India, as 65% of the country is susceptible to strong earthquakes. In this paper, a 15-story building is designed using seismic design codes ACI08, IS1893, EC8 and TEC07. The performance of the designed building is evaluated using relevant time history records available in India. It is found that the design of buildings as per EC8 and TEC07 gives better performance and more control while designing structures for earthquakes. Also, the design tools that support performance estimation based on structural testing help to give accurate performance results. This study brings out the gap between anticipated performance and obtained performance in the Indian context.

Energy Efficient Tri-State CNFET Ternary Logic Gates

Abstract: Power consumption and especially leakage power are the main concerns of nano MOSFET technology. On the other hand, binary circuits face a huge number of interconnection wires, which results in power dissipation and area. Researchers introduced emerging nanodevices and multiple-valued logic (MVL) as two feasible solutions to overcome the challenges mentioned above. Carbon nanotube field-effect transistor (CNFET) is one of the emerging technologies that has some unique properties and advantages over MOSFET, such as adjusting the carbon nanotube (CNT) diameters to have the desired threshold voltage and have the same mobility as P-FET and N-FET transistors. In this paper, we present a novel method for designing ternary logic circuits based on CNFETs. Each of our designed logic circuits implements a logic function and its complementary via a control signal. Also, these circuits have a high impedance state, which saves power while the circuits are not in use. Moreover, we designed a two-digit adder/ subtractor and a power-efficient ternary logic arithmetic logic unit (ALU) based on the proposed gates. The proposed ternary circuits are simulated using HSPICE via standard 32 nm CNFET technology. The simulation results indicate the designs’ correct operation under different process, voltage, and temperature (PVT) variations. Also, simulation results show that the two-digit adder/ subtractor using our proposed gates has 12X and 5X lower power consumption and power-delay product (PDP), respectively, compared to previous designs.

Investigation the efficacy of fuzzy logic implementation at image-guided radiotherapy

Abstract: At image-guided radiotherapy, technique, different imaging, and monitoring systems are utilized for (i) organs border detection and tumor delineation during the treatment planning process and (ii) patient setup and tumor localization at pretreatment step and (iii) real-time tumor motion tracking for dynamic thorax tumors during the treatment. In this study, the effect of fuzzy logic is quantitatively investigated at different steps of image-guided radiotherapy. Fuzzy logic-based models and algorithms have been implemented at three steps, and the obtained results are compared with commonly available strategies. Required data are (i) real patients treated with Synchrony Cyberknife system at Georgetown University Hospital for real-time tumor motion prediction, (ii) computed tomography images taken from real patients for geometrical setup, and also (iii) tomography images of an anthropomorphic phantom for tumor delineation process. In real-time tumor tracking, the targeting error averages of the fuzzy correlation model in comparison with the Cyberknife modeler are 4.57 mm and 8.97 mm, respectively, for a given patient that shows remarkable error reduction. In the case of patient geometrical setup, the fuzzy logic-based algorithm has better influence in comparing with the artificial neural network, while the setup error averages is reduced from 1.47 to 0.4432 mm using the fuzzy logic-based method, for a given patient.Finally, the obtained results show that the fuzzy logic based image processing algorithm exhibits much better performance for edge detection compared to four conventional operators. This study is an effort to show that fuzzy logic based algorithms are also highly applicable at image-guided radiotherapy as one of the important treatment modalities for tumor delineation, patient setup error reduction, and intrafractional motion error compensation due to their inherent properties.

Acceleration Response-Based Adaptive Strategy for Vibration Control and Location Optimization of Magnetorheological Dampers in Multistoried Structures

Abstract: Optimization and deployment of control systems with multiple control devices incorporated into a structure is a daunting task. The optimum location of the control device is intrinsically co...