Classification of DoS Attacks in Smart Underwater Wireless Sensor Network

As per the most recent literature, Orthogonal Frequency Division Multiplexing (OFDM), a multi access technique, is considered most suitable for the 3G, 4G and 5G techniques in high speed wireless communication. What made OFDM most popular is its ability to deliver high bandwidth efficiency and superior data rate. Besides it, high value of peak to average power ratio (PAPR) and Inter Carrier Interference (ICI) are the challenges to tackle down via appropriate mitigation scheme. As a research contribution in the present work, an improved self-cancellation (SC) technique is designed and simulated through Simulink to mitigate the effect of ICI. This novel proposed technique (Improved SC) is designed over discrete wavelet transform (DWT) based OFDM and compared with conventional SC scheme over different channel conditions i.e. AWGN and Rayleigh fading environments. It is found that proposed DWT-OFDM with Improved SC scheme outperforms conventional SC technique significantly, under both AWGN and Rayleigh channel conditions. Further, in order to justify the novelty in the research contribution, a Split-DWT based Simulink model for Improved SC scheme is investigated to analyse the BER performance. This Split-DWT based Simulink model presented here foretells the future research potential in wavelet hybridization of OFDM to side-line ICI effects more efficiently.

     

NMOS IC's for clock and data regeneration in gigabit-per-secondoptical-fiber receivers

The design and performance of two essential analog circuits in optical-fiber receivers is described. A time-interleaved decision circuit is capable of regenerating 35-mV nonreturn-to-zero (NRZ) data inputs to full logic levels at 1.1 Gb/s with 10^-11 bit error rate (BER), and a phase-locked loop (PLL) extracts the clock from a 2 ²³ long pseudorandom sequence at 1.5 Gb/s with 13-ps r.m.s. jitter. The two circuits have been implemented as 1-μm NMOS ICs, and in their core area dissipate 200 and 350 mW, respectively     

TEM00 terawatt amplification by use of micro-optic spatial mode conversion

Micro-optic technology is used in a terawatt multipass Ti:sapphire amplifier to convert high-multimode, 532-nm radiation from an unstable resonator Nd:YAG laser into a TEM00 amplified output without sacrificing the amplifier-to-pump energy conversion efficiency. Experimental measurements and Fourier analysis of the spatial mode show a 3.8-fold increase in the peak irradiance and an order-of-magnitude improvement in the spatial contrast.     

Decision and clock recovery circuits for gigahertz optical fiber receivers in silicon NMOS

New design techniques for implementing a data and clock recovery circuit on a silicon NMOS monolithic IC employing 1-μm feature sizes, and operating at speeds greater than 2 Gbit/s are described. A clocked comparator can resolve a 60-mV peak-to-peak signal into logic levels at 2 Gbit/s. The circuit can tolerate a 100° phase margin between the incoming signal and the clock. An NRZ data rate of 4 Gbit/s may be resolved by two such multiplexed circuits following a preamplifier in the same technology. A VCO capable of operation at 2 GHz in a PLL, that does not require off-chip components, is also described. An observer loop concept is employed in the PLL to align the recovered clock signal with the incoming data.     

Cluster Estimation in Terrestrial and Underwater Sensor Networks

Wireless Personal Communications - In Wireless Sensor Network (WSN), clustering is considered as an efficient network topology which maximizes the received data at the sink by minimizing a direct...     

Chalcone JAI‐51 improves efficacy of synchrotron microbeam radiation therapy of brain tumors

Microbeam radiation therapy (MRT), a preclinical form of radiosurgery, uses spatially fractionated micrometre‐wide synchrotron‐generated X‐ray beams. As MRT alone is predominantly palliative for animal tumors, the effects of the combination of MRT and a newly synthesized chemotherapeutic agent JAI‐51 on 9L gliosarcomas have been evaluated. Fourteen days (D14) after implantation (D0), intracerebral 9LGS‐bearing rats received either MRT, JAI‐51 or both treatments. JAI‐51, alone or immediately after MRT, was administered three times per week. Animals were kept up to ～20 weeks after irradiation or sacrificed at D16 or D28 after treatment for cell cycle analysis. MRT plus JAI‐51 increased significantly the lifespan compared with MRT alone (p = 0.0367). JAI‐51 treatment alone had no effect on rat survival. MRT alone or associated with JAI‐51 induced a cell cycle blockade in G2/M (p < 0.01) while the combined treatment also reduced the proportion of G0/G1 cells. At D28 after irradiation, MRT and MRT/JAI‐51 had a smaller cell blockade effect in the G2/M phase owing to a significant increase in tumor cell death rate (<2c) and a proportional increase of endoreplicative cells (>8c). The combination of MRT and JAI‐51 increases the survival of 9LGS‐bearing rats by inducing endoreduplication of DNA and tumor cell death; further, it slowed the onset of tumor growth resumption two weeks after treatment.     

Energy Conservation Using RR Algorithm in Dynamic Cluster Based WSN

Wireless Personal Communications - The energy consumption during the cluster head selection phase in a hierarchal and dynamic cluster based wireless sensor network had been considered insignificant...     

Structural, optical and electronic properties of oxidized AIN thin films at different temperatures

We report on the properties of a novel insulator, AlO:N for application in semiconductors produced by thermally oxidizing AlN thin films. The process steps were similar to those used for SiO₂, creating the possibility of a new technology for metal-insulator-semiconductor field effect devices and integrated circuits. Thin films of AlN were deposited by radio-frequency magnetron reactive sputtering on p-type silicon or fused quartz substrates. As-deposited AlN film thickness ranged from 0.05 to 0.7 μm, with polycrystalline structure revealed by x-ray diffraction. Oxidation was performed under O₂ flow at 800 to 1100°C for 1–4 h. AlN films were oxidized partially or fully into Al₂O₃, depending on initial thickness, oxidation temperature and time. X-ray diffraction indicates the presence of several phases of Al₂O₃ at 1000°C, whereas at 1100°C, only the α-Al₂O₃ phase was found. Considering the importance of surface field effect device applications, the surfaces of oxidized films were examined with atomic force microscopy in air, and a clear change was observed in the surface structure of the oxidized film from that of as-deposited AlN films. Capacitance-voltage measurements of metal-oxide-semiconductor structures yielded a dielectric constant of AlO:N between 8–12 and a net oxide-trapped-charge density of ∼10¹¹ cm⁻². Using Fourier transform infrared spectrometry transmittance and reflectance, some α-Al₂O₃ modes were observed. In this paper, we describe the general properties of the oxide thin films, bulk and interface, at different temperatures.