125 research outputs found

    A Four Slot Dual Feed and Dual Band Reconfigurable Antenna for Fixed Satellite Service Applications

    Get PDF
    A dual feed and dual-band reconfigurable antenna is designed, analyzed, and prototyped in this work for fixed satellite service communication applications. The designed model occupies the compact dimension of 24X21X1.2 mm on FR4 substrate and provides an input impedance of 50 ohms at both ports. The proposed model offers additional circular polarization characteristics at both the resonating bands. The PIN diode-based switching conditions, and the frequency reconfigurability analysis in both simulation and measurement are almost match. The combination of dual-band resonance, frequency reconfigurable nature, and compact dimension makes this model an attractive candidate in the specified field with considerable gain (8.5 dB) and efficiency (80%)

    A Bio-Crypto Protocol for Password Protection Using ECC

    Get PDF
    In  information  security the  following security parameters like, integrity , non repudiation and confidentiality , authentication   must be satisfied.  To avoid thievery of organization resources  it needs be secured in more efficient way  and there is always demand  for different levels of security attacks include virus , brute force and Eveadroper  in business that  organizations make use of voice biometrics an attractive low-cost. Voice biometrics is the  cheapest  among the  other biometrics and used all levels for management to buy readily available metric and it is the way of  identifying individuals remotely  with high level of accuracy . In this work, we have been designed a  new  password- authentication approach  that provides security  using voice biometrics for authentication and uses the device  itself into an authenticator which uses  voice itself as its passwords and we are primarily interested in keys that can be temporally reproduced on the same device from the same user’s voice. Public and private keys are generated  randomly from the user's voice  and stored in the voice file(.wav).This Method uses voice recognition , include the operation of  register( recording feature ) or voice prints  and  storing of one or more voice passwords into the  database. It uses ECDSA to perform the authentication process that matching the  voice sample  with the database. The recognition, entity makes the database  to decide that  the sample is matched to perform an operation or not. Our proposed approach  generates cryptographic keys from voice input itself and this algorithm developed an adhoc basis. It can effectively defend  attacks specially brute force attack in system networks

    Mapping of fluorosis affected villages

    Get PDF
    Excess fluoride in drinking water sources beyond a tolerance limit is responsible for the disease ‘fluorosis’, a serious public health problem in several parts of the world. Identification and mapping of fluorosis affected villages is the first step in the direction of mitigating and controlling the problem. A systematic study has been carried out in order to map the fluorotic villages of Dindigul Anna district of Tamil Nadu, South India and a suitable methodology has been developed for the purpose. This methodology for mapping the fluorosis affected villages is presented in this paper

    Defluoridation technology based on activated alumina

    Get PDF
    In this paper the experiments related to the development of defluoridation unit at domestic level for a 3 mg/1 flouride water, using activated alumina are presented in detail. The design and other specifications of the defluoridation unit are given. Details regarding the field studies in a fluorosis - affected village nearby Gandhigram are also discussed

    Noise Removal in Microarray Images Using Variational Mode Decomposition Technique

    Get PDF
    Microarray technology allows the simultaneous monitoring of thousands of genes in parallel. Based on the gene expression measurements, microarray technology have proven powerful in gene expression profiling for discovering new types of diseases and for predicting the type of a disease. Enhancement, Gridding, Segmentation and Intensity extraction are important steps in microarray image analysis. This paper presents a noise removal method in microarray images based on Variational Mode Decomposition (VMD). VMD is a signal processing method which decomposes any input signal into discrete number of sub-signals (called Variational Mode Functions) with each mode chosen to be its band width in spectral domain. First the noisy image is processed using 2-D VMD to produce 2-D VMFs. Then Discrete Wavelet Transform (DWT) thresholding technique is applied to each VMF for denoising.  The denoised microarray image is reconstructed by the summation of VMFs.  This method is named as 2-D VMD and DWT thresholding method. The proposed method is compared with DWT thresholding and BEMD and DWT thresholding methods. The qualitative and quantitative analysis shows that 2-D VMD and DWT thresholding method produces better noise removal than other two methods

    A Novel Energy Aware Clustering Mechanism with Fuzzy Logic in MANET Environment

    Get PDF
    A Mobile Ad Hoc Networks (MANETs) comprises of the vast range of devices such as sensors, smart phones, laptops and other mobile devices that connect with each other across wireless networks and collaborate in a dispersed fashion to offer network functions in the absence of a permanent infrastructure. The Cluster Head (CH) selection in a clustered MANET is still crucial for lowering each node's energy consumption and increasing the network's lifetime. However, in existing clustering mechanism trust of the all nodes are presumed those causes increased challenge in the MANET environment. Security is a crucial factor when constructing ad-hoc networks. In a MANET, energy consumption in route optimization is dependent on network resilience and connectivity. The primary objective of this study is to design a reliable clustering mechanism for MANETs that takes energy efficiency into account. For trusted energy-efficient CH in the nodes, a safe clustering strategy integrating energy-efficient and fuzzy logic based energy clustering is proposed to address security problems brought about by malicious nodes and to pick a trustworthy node as CH. To improve the problem findings Bat algorithm (BAT) is integrated with Particle Swarm Optimization (PSO). The PSO technique is inspired because it imitates the sociological characteristics of the flock of the birds through random population. The BAT is a metaheuristic algorithm inspired by microbat echolocation behavior that uses pulse average with global optimization of the average path in the network. Hybrid Particle Swarm Optimization (HPSO) and BAT techniques are applied to identify the best route between the source and destination. According to the simulation results, the suggested Fuzzy logic Particle Swarm Optimization BAT (FLPSO-BAT) technique has a minimum latency of 0.0019 milliseconds, with energy consumption value of 0.09 millijoules, maximal throughput of 0.76 bits per sec and detection rate of 90.5% without packet dropping attack

    Serum butyrylcholinesterase in type 2 diabetes mellitus: a biochemical and bioinformatics approach

    Get PDF
    BACKGROUND: Butyrylcholinesterase is an enzyme that may serve as a marker of metabolic syndrome. We (a) measured its level in persons with diabetes mellitus, (b) constructed a family tree of the enzyme using nucleotide sequences downloaded from NCBI. Butyrylcholinesterase was estimated colorimetrically using a commercially available kit (Randox Lab, UK). Phylogenetic trees were constructed by distance method (Fitch and Margoliash method) and by maximum parsimony method. RESULTS: There was a negative correlation between serum total cholesterol and butyrylcholinesterase (-0.407; p < 0.05) and between serum LDL cholesterol and butyrylcholinesterase (-0.435; p < 0.05). There was no statistically significant correlation among the other biochemical parameters. In the evolutionary tree construction both methods gave similar trees, except for an inversion in the position of Sus scrofa (M62778) and Oryctolagus cuniculus (M62779) between Fitch and Margoliash, and maximum parsimony methods. CONCLUSION: The level of butyrylcholinesterase enzyme was inversely related to serum cholesterol; dendrogram showed that the structures from evolutionarily close species were placed near each other

    4U2206+54 - an Unusual High Mass X-ray Binary with a 9.6 Day Orbital Period but No Strong Pulsations

    Get PDF
    Rossi X-ray Timing Explorer All-Sky Monitor observations of the X-ray source 4U2206+54, previously proposed to be a Be star system, show the X-ray flux to be modulated with a period of approximately 9.6 days. If the modulation is due to orbital variability then this would be one of the shortest orbital periods known for a Be star X-ray source. However, the X-ray luminosity is relatively modest whereas a high luminosity would be predicted if the system contains a neutron star accreting from the denser inner regions of a Be star envelope. Although a 392s pulse period was previously reported from EXOSAT observations, a reexamination of the EXOSAT light curves does not show this or any other periodicity. An analysis of archival RXTE Proportional Counter Array observations also fails to show any X-ray pulsations. We consider possible models that may explain the properties of this source including a neutron star with accretion halted at the magnetosphere and an accreting white dwarf.Comment: Accepted for publication in the Astrophysical Journa

    The Outbursts and Orbit of the Accreting Pulsar GS 1843-02 = 2S 1845-024

    Get PDF
    We present observations of a series of 10 outbursts of pulsed hard X-ray flux from the transient 10.6 mHz accreting pulsar GS 1843-02, using the Burst and Transient Source Experiment on the Compton Gamma Ray Observatory. These outbursts occurred regularly every 242 days, coincident with the ephemeris of the periodic transient GRO J1849-03 (Zhang et al. 1996), which has recently been identified with the SAS 3 source 2S 1845-024 (Soffitta et al. 1998). Our pulsed detection provides the first clear identification of GS 1843-02 with 2S 1845-024. We present a pulse timing analysis which shows that the 2S 1845-024 outbursts occur near the periastron passage of the neutron star's highly eccentric (e = 0.88+-0.01) 242.18+-0.01 day period binary orbit about a high mass (M > 7 solar masses) companion. The orbit and transient outburst pattern strongly suggest the pulsar is in a binary system with a Be star. Our observations show a long-term spin-up trend, with most of the spin-up occurring during the outbursts. From the measured spin-up rates and inferred luminosities we conclude that an accretion disk is present during the outbursts.Comment: Accepted for publication in Astrophysical Journa

    Absorption of high-energy gamma rays in Cygnus X-3

    Get PDF
    The microquasar Cygnus X-3 was detected at high energies by the gamma-ray space telescopes AGILE and Fermi. The gamma-ray emission is transient, modulated with the orbital period and seems related to major radio flares, i.e. to the relativistic jet. The GeV gamma-ray flux can be substantially attenuated by internal absorption with the ambient X-rays. In this study, we examine quantitatively the effect of pair production in Cygnus X-3 and put constraints on the location of the gamma-ray source. Cygnus X-3 exhibits complex temporal and spectral patterns in X-rays. During gamma-ray flares, the X-ray emission can be approximated by a bright disk black body component and a non-thermal tail extending in hard X-rays, possibly related to a corona above the disk. We calculate numerically the exact optical depth for gamma rays above a standard accretion disk. Emission and absorption in the corona are also investigated. GeV gamma rays are significantly absorbed by soft X-rays emitted from the inner parts of the accretion disk. The absorption pattern is complex and anisotropic. Isotropization of X-rays due to Thomson scattering in the companion star wind tends to increase the gamma-ray opacity. Gamma rays from the corona suffer from strong absorption by photons from the disk and cannot explain the observed high-energy emission, unless the corona is unrealistically extended. The lack of absorption feature in the GeV emission indicates that high-energy gamma rays should be located at a minimum distance ~10^8-10^10 cm from the compact object. The gamma-ray emission is unlikely to have a coronal origin.Comment: 11 pages, 9 figures, accepted for publication in Astronomy and Astrophysic
    corecore