Search

Soft computing techniques play a basic role in our life from a medical facility to weather forecasting and with the growing up of technology, the importance of soft computing techniques also increases in every field like Artificial intelligence, machine learning, etc. There are different methods to implement soft computing techniques. The use of Soft computing algorithms is one of the best methods to execute soft computing techniques but as speed is the important parameter this issue can be overcome by FPGA. Nowadays FPGA uses to achieve high speed. Due to pipelining concept in FPGA no of parameters of output can be verified simultaneously.

Nanocomposites of piezoelectric PVDF doped with Cd0.99Eu0.01SiO3 of varying concentration was prepared by spin coating technique. The prepared nanocomposites were investigated by X-ray diffraction technique and it showed an α to β transformation compared to pristine PVDF. This phase exhibits piezoelectric property employed in the design of Sensors and Actuators. SEM micrographs indicated a modification in surface morphology of the nanocomposites. Results of EDX indicate the incorporation of the elements of the nanodopant in PVDF. Differential Scanning Calorimetry showed an increase in degree of crystallinity. Optical bandgap energy of the nanocomposites increased with increase in concentration of nanodopant. Dielectric studies showed an enhancement in Dielectric permittivity and AC conductivity of the nanocomposites which can be employed in the design of energy storage devices

Software Defined Networks (SDN) provides central control over the network and the commands can be applied on its controller and switches through the interfaces. It has a central element, called as controller that maintains records and controls over the entire network activities. Hence, it is necessary to protect the controller, from being unreachable to the hosts that are connected to it. The unavailability of the controller can result in Denial of Service (DoS)/ Distributed Denial of Service (DDoS) attack. This paper presents the utility of the central controlling facilities to detect attacks and to mitigate them using an easy approach which can be implemented on the controller. The approach is based on the concept of entropy which is an important statistic of an SDN is its entropy. By observing the variation in the entropy, the attack on the controller can be detected before the controller becomes unreachable. Simulations and numerical results show the effectiveness of the proposed method in detecting and preventing DDoS attacks at an early stage.

The mobile communication industry around the globe is striving for new technologies as future wireless cellular systems are necessary to provide higher user data rates and offer smooth user access to the backbone communication network. The efficient data compression methods and error correcting codes are two of the most prominent approaches that ease applications in the overhead-mentioned systems and services. The major focus of this paper is on the performance analysis of turbo compressive codes using EXIT charts. The major advantages of the EXIT chart technique are the fact that they can be computed quickly, making it much more convenient than the traditionally simulated BER performance curves. Furthermore, the EXIT charts are a powerful technique which allows analyzing the constituent decoders in an iterative decoder separately.

Large-area PVDF thin films have been prepared and characterized for quasi-static and high frequency dynamic strain sensing applications. These films are prepared using hot press method and the piezoelectric phase (beta-phase) has been achieved by thermo-mechanical treatment and poling under DC field. The fabricated films have been characterized for quasi-static strain sensing and the linear strain-voltage relationship obtained is promising. In order to evaluate the ultrasonic sensing properties, a PZT wafer has been used to launch Lamb waves in a metal beam on which the PVDF film sensor is bonded at a distance. The voltage signals obtained from the PVDF films have been compared with another PZT wafer sensor placed on the opposite surface of the beam as a reference signal. Due to higher stiffness and higher thickness of the PZT wafer sensors, certain resonance patterns significantly degrade the sensor sensitivity curves. Whereas, the present results show that the large-area PVDF sensors can be superior with the signal amplitude comparable to that of PZT sensors and with no resonance-induced effect, which is due to low mechanical impedance, smaller thickness and larger area of the PVDF film. Moreover, the developed PVDF sensors are able to capture both A(0) and S-0 modes of Lamb wave, whereas the PZT sensors captures only A(0) mode in the same scale of voltage output. This shows promises in using large-area PVDF films with various surface patterns on structures for distributed sensing and structural health monitoring under quasi-static, vibration and ultrasonic situations. (C) 2010 Elsevier B.V. All rights reserved.

Ni–Co composites incorporated with SiC particles of nano and micron size were produced by electrodeposition. The effect of cobalt content on the particle incorporation, microhardness, surface morphology and tribological behaviour has been studied. The Ni rich Ni–Co composite exhibited enhanced microhardness values. However, no appreciable increase in the microhardness was observed for Co rich Ni–Co–SiC composites. Scanning electron microscope, energy dispersive X-ray analysis and X-ray diffraction studies were used to characterize the coatings. A change in surface morphology, phase structure and SiC incorporation was observed with increase in cobalt content. Pin-on-disc tribo tester was employed to study the wear and friction behaviour of the Ni–Co–SiC coatings. The tribo studies indicated that the wear volume loss was less for micron SiC reinforced Ni–Co composites compared to nano SiC reinforced composites. However, no appreciable variation in the coefficient of friction was observed for both Ni rich and Co rich Ni–Co–SiC composites.

Autocatalytic ternary Ni-Sn-P, Ni-W-P and quaternary Ni-W-Sn-P films were prepared using alkaline citrate-based baths and compared with binary Ni-P coatings. Energy dispersive analysis of X-ray (EDAX) showed that binary Ni-P deposit contained 11.3 wt.% of phosphorus. Codeposition of tungsten in Ni-P matrix resulted in ternary Ni-W-P with 5 wt.% P and 7.8 wt.% of tungsten. Incorporation of tin led to ternary Ni-Sn-P deposit containing 0.4 wt.% Sn and 10.3 wt.% P. Presence of both sodium tungstate and sodium stannate in the basic bath had resulted in quaternary coating with 6.9 wt.% W, traces of Sn and 6.4 wt.% P. X-ray diffraction patterns of all the deposits revealed a single, broad peak which showed the nanocrystalline nature of the deposits. For the first time in related literature, the presence of a metastable phase Ni12P5 in ternary deposits is reported in the present study. Metallographic cross-sections of all the deposits revealed the banded/lamellar structure. Scanning electron microscopy (SEM) studies of the deposits showed smooth nodules for ternary deposits, but coarse and well-defined nodules for quaternary deposits. DSC studies of phase transformation behavior of the ternary Ni-Sn-P deposit revealed a single sharp exothermic peak at 365 xB0;C. However, ternary Ni-W-P and quaternary Ni-W-Sn-P deposits exhibited a low temperature peak at 300 xB0;C, a split type high temperature peak at 405 and 440 xB0;C and a very high temperature peak at 550 xB0; C. Higher activation energy values were obtained for W-based alloy deposits. Presence of W and Sn has helped to retain high microhardness values even at higher temperatures indicating an improved thermal stability.

Single-phase CrN and CrAlN coatings were deposited on silicon and mild steel substrates using a reactive DC magnetron sputtering system. The structural characterization of the coatings was done using X-ray diffraction (XRD). The XRD data showed that both the CrN and CrAlN coatings exhibited B1 NaCl structure with a prominent reflection along (200) plane. The bonding structure of the coatings was characterized by X-ray photoelectron spectroscopy and the surface morphology of the coatings was studied using atomic force microscopy. Subsequently, nanolayered CrN/CrAlN multilayer coatings with a total thickness of approximately 1 m were deposited on silicon substrates at different modulation wavelengths (). The XRD data showed that all the multilayer coatings were textured along {200}. The CrN/CrAlN multilayer coatings exhibited a maximum nanoindentation hardness of 3125 kg/mm2 at a modulation wavelength of 72 A, whereas single layer CrN and CrAlN deposited under similar conditions exhibited hardness values of 2375 and 2800 kg/mm2, respectively. Structural changes as a result of heating of the multilayer coatings in air (400-800C) were characterized using XRD and micro-Raman spectroscopy. The XRD data showed that the multilayer coatings were stable up to a temperature of 650C and peaks pertaining to Cr2O3 started appearing at 700C. These results were confirmed by micro-Raman spectroscopy. Nanoindentation measurements performed on the heat-treated coatings revealed that the multilayer coatings retained hardness as high as 2250 kg/mm2 after annealing up to a temperature of 600°C.

The X-ray diffraction patterns are recorded from polycrystalline iron sample compressed in a diamond anvil cell up to 55 GPa. The maximum micro-stress in the sample, a measure of compressive strength, is derived from the line-width analysis. The strength of iron in the body centered cubic (BCC)-phase is 1.1amp;plusmn;0.2 GPa. This value is in good agreement with the strength derived from the hardness vs. grain-size data. The strength increases steeply during the BCC-hexagonal closed packed (HCP) transition. The strength-pressure data for HCP-iron fit the relation amp;sigma; = 2.9 + 0.028 P, where amp;sigma; and P are the compressive strength and pressure in GPa, respectively. The present results agree well with those obtained from the line shift analysis carried out in earlier studies.

TiAlN films were deposited on silicon (1 1 1) substrates from a TiAl target using a reactive DC magnetron sputtering process in Ar+N 2 plasma. Films were prepared at various nitrogen flow rates and TiAl target compositions. Similarly, CrN films were prepared from the reactive sputtering of Cr target. Subsequently, nanolayered TiAlN/CrN multilayer films were deposited at various modulation wavelengths ( Λ ). X-ray diffraction (XRD), energy dispersive X-ray analysis, nanoindentation and atomic force microscopy were used to characterize the films. The XRD confirmed the formation of superlattice structure at low modulation wavelengths. The maximum hardness of TiAlN/CrN multilayers was 3900 kg/mm 2 , whereas TiAlN and CrN films exhibited maximum hardnesses of 3850 and 1000 kg/mm 2 , respectively. Thermal stability of TiAlN and TiAlN/CrN multilayer films was studied by heating the films in air in the temperature range ( T A ) of 500–900 °C for 30 min. The XRD spectra revealed that TiAlN/CrN multilayers were stable up to 800 °C and got oxidized substantially at 900 °C. On the other hand, the TiAlN films were stable up to 700 °C and got completely oxidized at 800 °C. Nanoindentation measurements performed on the films after heat treatment showed that TiAlN retained a hardness of 2200 kg/mm 2 at T A =700 °C and TiAlN/CrN multilayers retained hardness as high as 2600 kg/mm 2 upon annealing at 800° C.

Nanolayered TiN/CrN multilayer coatings were deposited on silicon substrates using a reactive DC magnetron sputtering process at various modulation wavelengths (?), substrate biases (VB) and substrate temperatures (TS). X-ray diffraction (XRD), nanoindentation and atomic force microscopy (AFM) were used to characterize the coatings. The XRD confirmed the formation of superlattice structure at low modulation wavelengths. The maximum hardness of the TiN/CrN multilayers was 3800kg/mm2 at ?=80 A?, VB=-150V and T S=400xB0;C. Thermal stability of TiN, CrN and TiN/CrN multilayer coatings was studied by heating the coatings in air in the temperature range (TA) of 400-800xB0;C. The XRD data revealed that TiN/CrN multilayers retained superlattice structure even up to 700xB0;C and oxides were detected only after TAamp;gt;750xB0;C, whereas for single layer TiN and CrN coatings oxides were detected even at 550xB0;C and 600xB0;C, respectively. Nanoindentation measurements showed that TiN/CrN multilayers retained a hardness of 2800kg/mm2 upon annealing at 700xB0;C, and this decrease in the hardness was attributed to interdiffusion at the interfaces. xA9; 2003 Elsevier Ltd. All rights reserved.