Stochastic dynamic programming model for optimal resource allocation in vehicular ad hoc networks

Vehicular ad hoc network (VANET) is an emerging trend where vehicles communicate with each other and possibly with a roadside unit to assist various applications like monitoring, managing and optimizing the transportation system. Collaboration among vehicles is significant in VANET. Resource constraint is one of the great challenges of VANETs. Because of the absence of centralized management, there is pitfall in optimal resource allocation, which leads to ineffective routing. Effective reliable routing is quite essential to achieve intelligent transportation. Stochastic dynamic programming is currently employed as a tool to analyse, develop and solve network resource constraint and allocation issues of resources in VANET. We have considered this work as a geographical-angular-zone-based two-phase dynamic resource allocation problem with a homogeneous resource class. This work uses a stochastic dynamic programming algorithm based on relaxed approximation to generate optimal resource allocation strategies over time in response to past task completion status history. The second phase resource allocation uses the observed outcome of the first phase task completion to provide optimal viability in resulting decisions. The proposed work will be further extended for the scenario that deals with heterogeneous resource class. Simulation results show that the proposed scheme works significantly well for the problems with identical resources.     

An Intelligent Semanticification Rules Enabled User-Specific Healthcare Framework Using IoT and Deep Learning Techniques

Wireless Personal Communications - Things or device under the Internet of Things, when connected to the internet, becomes a product, offers various applications and services for end-users. Existing...     

Preparation and Impedance Analysis of Biodegradable Polymer Polyvinyl Alcohol with Amino Acid,Arginine

Biodegradable polymers have an innumerable use in the field of biomedicine, especially in drug delivery system. Polyvinyl alcohol is one of the biodegradable polymer used as a carrier for drug delivery. Amino acids are necessary for maintaining good health for human beings. The present study focuses on the interaction between polyvinyl alcohol and amino acids. An effort is being taken to prepare polymer membrane based on polyvinyl alcohol complexed with different concentration of arginine, a type of amino acids using water as solvent by solution-casting technique. The amphorousity and complex formation between polyvinyl alcohol and Arignine have been confirmed by X-ray diffraction and FTIR spectroscopy, respecticvely. The thermal behavior of PVA–arginine complexes has been analyzed by differential scanning calorimetry. From AC impedance spectroscopy, ion transport mechanism has been investigated in detail. By using Almond and West formulisms, the parameter such as ion hopping frequency ω_p, has been calculated. The polymer membrane 75 Mwt% PVA:25 Mwt% arginine has the highest ionic conductivity as 1.97 × 10^?6 S cm^?1 at ambient temperature.     

A new algorithm based on Givens rotations for solving linearequations on fault-tolerant mesh-connected processors

In this paper, we propose a new I/O overhead free Givens rotations based parallel algorithm for solving a system of linear equations. The algorithm uses a new technique called two-sided elimination and requires an N×(N+1) mesh-connected processor array to solve N linear equations in (5N-log N-4) time steps. The array is well suited for VLSI implementation as identical processors with simple and regular interconnection pattern are required. We also describe a fault-tolerant scheme based on an algorithm based fault tolerance (ABFT) approach. This scheme has small hardware and time overhead and can tolerate up to N processor failures     

Effects on corrosion resistance of rebar subjected to deep cryogenic treatment

An attempt has been made to evaluate the effect of deep cryogenic treatment on the corrosion resistance of rebar. Corrosion behavior of samples subjected to deep cryogenic treatment and samples tempered after deep cryogenic treatment was studied by linear polarization method. The Vickers hardness and ultimate tensile strength of the samples were also measured. The possible mechanism for increase in corrosion resistance has been explained based on Scanning electron micrographs (SEM) and X-Ray diffraction (XRD) study. The morphology of the corroded surfaces of the samples was studied using Atomic force microscopy (AFM). It was found that there is 69 % improvement in corrosion resistance because of deep cryogenic treatment, further it was seen that the increase in corrosion resistance was due to the contribution of increased pearlite phase. Deep cryogenic treatment had no adverse effect on ultimate tensile strength and hardness, which are crucial properties to be considered for rebar.     

Effect of fluorine doping on the structural,optical and electrical properties of spray deposited cadmium stannate thin films

Cadmium stannate (Cd₂SnO₄) thin films were coated on Corning 1737 glass substrates at 540 °C by spray pyrolysis technique, from the aqueous solution of cadmium acetate and tin (II) chloride precursors. Fluorine doped Cd₂SnO₄ (F: Cd₂SnO₄) thin films were prepared by adding ammonium fluoride in the range of 0–5 wt% of the total weight of cadmium acetate and tin (II) chloride in the spray solution. Thickness of the prepared films is about 300 nm. X-ray diffraction analysis of the Cd₂SnO₄ and 3 wt% F: Cd₂SnO₄ films shows the signature for the growth along (222) direction. Scanning electron micrographs showed that fluorine doping effectively modifies the surface morphology of Cd₂SnO₄ films. Average optical transmittance in the visible region (500–850 nm) for Cd₂SnO₄ is ~79% and it is increased to ~83% for 1 wt% doping concentration of the NH₄F in the solution. Fluorescence spectra of F: Cd₂SnO₄ (1 wt% and 3 wt%) exhibit peak at 601 nm. F: Cd₂SnO₄ film (1 wt%) shows mobility of ~42 cm²/V s, carrier concentration of ~9.5×10¹⁹ cm^?3 and resistivity of ~1.5×10^?3 Ω cm.     

Pulse multiplication in AC-DC converters for harmonic mitigation in vector-controlled induction motor drives

In this paper, an autotransformer with reduced kilovoltampere rating for 24-pulse ac-dc converter fed vector controlled induction motor drives (VCIMDs) is presented for harmonic current reduction. The 24-pulse operation is achieved using dc ripple reinjection technique in 12-pulse ac-dc converters. The proposed novel harmonic mitigator is found capable of suppressing up to 21st harmonic in the supply current. The procedure for the design of autotransformer for proposed ac-dc converter is presented to show the flexibility in the design for making it a cost-effective replacement suitable for retrofit applications, where presently a 6-pulse diode bridge rectifier is used. The effect of load variation on VCIMD is also studied to demonstrate the effectiveness of the proposed ac-dc converter. A set of power quality indices on input ac mains and on dc bus for a VCIMD fed from other 24-pulse ac-dc converters are also given to compare their performance. The laboratory prototypes of proposed autotransformers based 12-pulse and 24-pulse ac-dc converters are developed and test results are presented to validate the developed design procedure and the simulation models of these ac-dc converters under varying loads.     

Synthesis and characterization of Carbon Nano Fiber/LiFePO4 composites for Li-ion batteries

Carbon Nano Fibers (CNFs) coated with LiFePO₄ particles have been prepared by a non-aqueous sol–gel technique. The functionalization of the CNFs by HNO₃ acid treatment has been confirmed by Raman and XPS analyses. The samples pure LiFePO₄ and LiFePO₄–CNF have been characterized by XRD, SEM, RAMAN, XPS and electrochemical analysis. The LiFePO₄–CNF sample shows better electrochemical performance compared to as-prepared LiFePO₄. LiFePO₄–CNF (10 wt.%) delivers a higher specific capacity (∼140 mAh g⁻¹) than LiFePO₄ with carbon black (25 wt.%) added after synthesis (∼120 mAh g⁻¹) at 0.1C.     

Pongamia Pinnata as a Green Corrosion Inhibitor for Mild Steel in 1N Sulfuric Acid Medium

Due to the harmful nature of the traditional inhibitors, in recent years researchers have an interest in using eco-friendly corrosion inhibitors. The plant extracts exhibit efficient corrosion inhibition properties due to the presence of a mixture of organic constituents starting from terpenoids to flavonoids. In the present study the inhibition of corrosion of mild steel in 1N H₂SO₄ solution using the leaf extract of Pongamia pinnata (P. pinnata) was investigated by the weight loss method, potentiodynamic polarization method and electrochemical impedance spectroscopy (EIS) technique. Characterization of the leaf extract of P. pinnata was carried out using Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GCMS) analysis. The effect of temperature and immersion time on the corrosion behavior of mild steel in sulfuric acid with different concentrations of P. pinnata was also studied. From the results it was found that the inhibition is mainly attributed to the adsorption of inhibitor molecules on the mild steel electrode surface. It was found that the adsorption of inhibitor molecules takes place according to the Langmuir, Temkin, and Freundlich adsorption isotherms. Kinetic as well as thermodynamic parameters were calculated, also confirming the strong interaction between inhibitor molecules and the electrode surface. The inhibition efficiency (I.E in %) was found to increase with increase in concentration of the inhibitor molecules and the maximum inhibition efficiency was attained at 100 ppm of the leaf extract. From the electrochemical studies it was found that the corrosion process was controlled by a mixed inhibition process and single charge transfer mechanism. Fourier transform infrared spectroscopy (FTIR) provided the confirmatory evidence for the adsorption of the extract molecules on the mild steel surface, which is responsible for the corrosion inhibition. Scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX) experiments also confirmed the presence of inhibitor molecules on the mild steel surface. From all these experimental results, it can be concluded that the leaf extract of P. pinnata acted as a good corrosion inhibitor for mild steel in 1N sulfuric acid medium even at lower inhibitor concentrations.     

A Novel Polygon Based 18-Pulse AC–DC Converter for Vector Controlled Induction Motor Drives

This paper presents a novel configuration of an autotransformer based 18-pulse ac-dc converter for improving the power quality at the point of common coupling (PCC) in variable frequency induction motor drives (VFIMDs). The polygon based connection of autotransformer for achieving 18-pulse rectification is utilized to result in reduction in rating of the magnetics. The design of the autotransformer is carried out for an 18-pulse ac-dc converter feeding a vector controlled induction motor drive (VCIMD). Moreover, the autotransformer design is modified for making it suitable for retrofit applications, where presently a 6-pulse diode bridge rectifier is used. The effect of load variation on VCIMD is also studied and the performance of the proposed 18-pulse ac-dc converter is compared in terms of different power quality indices on both ac as well as dc side with other ac-dc converters. A laboratory prototype of the proposed autotransformer based 18-pulse ac-dc converter feeding a 10-hp induction motor drive is developed to verify the design and simulated results