3,131 research outputs found

    Maximum Likelihood Decoder for Index Coded PSK Modulation for Priority Ordered Receivers

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    Index coded PSK modulation over an AWGN broadcast channel, for a given index coding problem (ICP) is studied. For a chosen index code and an arbitrary mapping (of broadcast vectors to PSK signal points), we have derived a decision rule for the maximum likelihood (ML) decoder. The message error performance of a receiver at high SNR is characterized by a parameter called PSK Index Coding Gain (PSK-ICG). The PSK-ICG of a receiver is determined by a metric called minimum inter-set distance. For a given ICP with an order of priority among the receivers, and a chosen 2N2^N-PSK constellation we propose an algorithm to find (index code, mapping) pairs, each of which gives the best performance in terms of PSK-ICG of the receivers. No other pair of index code (of length NN with 2N2^N broadcast vectors) and mapping can give a better PSK-ICG for the highest priority receiver. Also, given that the highest priority receiver achieves its best performance, the next highest priority receiver achieves its maximum gain possible and so on in the specified order or priority.Comment: 9 pages, 6 figures and 2 table

    FORMULATION AND IN VITRO EVALUATION OF MATRIX TABLETS OF METOCLOPRAMIDE HYDROCHLORIDE

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    Objective: The purpose of present study was to formulate oral sustained release matrix tablet of metoclopramide hydrochloride and to evaluate the effect of varying concentrations of hydrophobic and hydrophilic polymers on drug release. Methods: Drug–excipients compatibility studies were carried out by using Fourier transform infrared spectroscopy (FTIR). The matrix tablets were prepared by direct compression technique using Xanthan gum and ethyl cellulose alone and in combination as release retardant. Dicalcium phosphate was used as diluent. The prepared matrix tablets were evaluated for their physicochemical parameters such as weight variation, hardness, friability, content uniformity and in vitro drug release studies were performed using USP-type II (paddle) dissolution apparatus. Results: Pre and post compression parameters were evaluated and all the parameters were found within the limit. The matrix tablets prepared with xanthan gum and combination of xanthan gum and ethyl cellulose were retarded the drug release upto 12 h. Ethyl cellulose alone could not control the drug release for 12 h. The Formulation with drug to xanthan gum (1:1.5), released 97.62 % of drug in 12 h. The kinetic treatment showed that the release of drug follows zero order kinetics (R 2=0.985). Korsmeyer and Peppas equation values of n were found to be in the range of 0.40-0.56, indicating that the drug release mechanism was diffusion. Conclusion: Matrix tablet is the simple, efficient and economic method to sustain the release of metoclopramide to prevent extrapyramidal side effects

    ChemInform Abstract: A Remarkably Simple One‐Step Procedure for the Preparation of α‐Bromo‐α,β‐Unsaturated Carbonyl Compounds

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    ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option

    DESIGN & FPGA IMPLEMENTATION OF EFFICIENT MULTIBAND OFDM USING DWT/DUC/DDC

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    To increase data rate of wireless medium with higher performance, OFDM (orthogonal frequency division multiplexing) is used. Here DWT (Discrete wavelet transforms) is adopted in place of FFT (Fast Fourier transform) for frequency translation. Modulation schemes such as 16-QAM (Quadrature amplitude modulation) have been used in the development of OFDM system using DWT. In this paper, I propose a DWT-IDWT based OFDM transmitter and receiver .It has been proven that all the wavelet families better over the IFFT-FFT implementation.. The wavelet filter used in the project is Bi-orthoganal (9,7) with N=2. The Project also include implementation of Digital Up Converter and Digital Down Converter at the transmitter and receiver part respectively. The project is implemented on FPGA by designing using Verilog HDL and System Generator

    Leveraging Machine Learning for Network Intrusion Detection in Social Internet Of Things (SIoT) Systems

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    This research investigates the application of machine learning models for network intrusion detection in the context of Social Internet of Things (SIoT) systems. We evaluate Convolutional Neural Network with Generative Adversarial Network (CNN+GAN), Generative Adversarial Network (GAN), and Logistic Regression models using the CIC IoT Dataset 2023. CNN+GAN emerges as a promising approach, exhibiting superior performance in accurately identifying diverse intrusion types. Our study emphasizes the significance of advanced machine learning techniques in enhancing SIoT security by effectively detecting anomalous behaviours within socially interconnected environments. The findings provide practical insights for selecting suitable intrusion detection methods and highlight the need for ongoing research to address evolving intrusion scenarios and vulnerabilities in SIoT ecosystems

    A Triangular-shaped Quarter-mode Substrate Integrated Waveguide based Antenna for WBAN Applications

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    In this study, a compact quarter-mode substrate integrated waveguide (QMSIW) based dual-band antenna is proposed for wireless body area network applications. A QMSIW resonator is realised by splitting the full-mode substrate integrated waveguide cavity along the perfect magnetic conductor walls. The proposed antenna preserves the fundamental mode TE110 and the third order mode TE220 of the square SIW cavity. The proposed antenna is linearly polarised in the lower band at 2.45 GHz and circularly polarised in the higher frequency band at 5.8 GHz. The on-body performance of the antenna is validated on a piece of pork muscle tissue and it has been found to be stable with respect to surroundings. The proposed antenna covers the ISM bands 44 MHz (2.445 GHz - 2.489 GHz) and 225 MHz (5.730 GHz - 5.955 GHz) at 2.45 GHz and 5.8 GHz, respectively. The measured gain of the antenna on pork tissue is 1.87 dBi and 5.5 dBi at two bands. In addition, the specific absorption rate is obtained of 0.65 mW/g and 1.51 mW/g at two bands (wext = 2 mm), averaged over 1 g of muscle with 100mW input power. Moreover, the simulated and experimental results demonstrate a good agreement

    Isolation, purification, characterization and applications of serine protease from Bacillus megaterium

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    Bacillus megaterium isolated from poultry farm soil was identified by standard biochemical tests and screened for the production of serine protease. Production of serine protease was done using 5 different medias by varying the type of amino acid added. The purification was done by salt precipitation, dialysis and DEAEcellulose ion exchange chromatography. The proline containing media obtained the highest fold purification out of the five different medias (leucine, lysine, proline, tryptophan and methionine cotaining media). The enzyme showedan optimal activity at the temperature 37°C and the pH 6 which are known as its optimum temperature and pH respectively. The enzyme was proved as a Mn2+ dependent serine protease as it was activated by Mn2+ ions and inhibited by PMSF. The molecular weight of the enzyme was determined by SDS-PAGE technique as around 30kDa. It showed an excellent detergent activity on the blood stains and a very good stability in presence of locally available detrgents. The enzyme acted on the keratin protein of the chicken feather and showed a degrading capacity on the protein. So it was proved that the recently studied serine protease has a keratinase activity also. From these datas I conclude that the protease isolated from Bacillus megaterium is a Mn2+ dependent serine protease which has both keratinase and detergent activity
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