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  Subjects -> BIOLOGY (Total: 3329 journals)
    - BIOCHEMISTRY (255 journals)
    - BIOENGINEERING (134 journals)
    - BIOLOGY (1586 journals)
    - BIOPHYSICS (49 journals)
    - BIOTECHNOLOGY (260 journals)
    - BOTANY (247 journals)
    - CYTOLOGY AND HISTOLOGY (30 journals)
    - ENTOMOLOGY (74 journals)
    - GENETICS (169 journals)
    - MICROBIOLOGY (271 journals)
    - MICROSCOPY (10 journals)
    - ORNITHOLOGY (28 journals)
    - PHYSIOLOGY (72 journals)
    - ZOOLOGY (144 journals)

BIOLOGY (1586 journals)            First | 1 2 3 4 5 6 7 8 | Last

Showing 801 - 1000 of 1720 Journals sorted alphabetically
Izvestiya Atmospheric and Oceanic Physics     Hybrid Journal   (Followers: 1)
Izvestiya, Physics of the Solid Earth     Hybrid Journal   (Followers: 2)
Jahangirnagar University Journal of Biological Sciences     Open Access   (Followers: 1)
Japanese Journal of Applied Physics     Full-text available via subscription   (Followers: 6)
JCI Insight     Open Access   (Followers: 3)
JDREAM : Journal of interDisciplinary REsearch Applied to Medicine     Open Access  
JETP Letters     Hybrid Journal   (Followers: 3)
Jornal Interdisciplinar de Biociências     Open Access  
Journal Biastatistics : Biomedics, Industry & Business And Social Statistics     Open Access  
Journal of Bacteriology & Parasitology     Open Access   (Followers: 5)
Journal of Bioanalysis & Biomedicine     Open Access   (Followers: 1)
Journal of Bioequivalence & Bioavailability     Open Access  
Journal of Bioremediation & Biodegradation     Open Access   (Followers: 4)
Journal of Computer Science & Systems Biology     Open Access   (Followers: 5)
Journal of Proteomics & Bioinformatics     Open Access   (Followers: 10)
Journal of Advanced Laboratory Research in Biology     Open Access   (Followers: 1)
Journal of Advances in Biology     Open Access   (Followers: 4)
Journal of Advances in Biology & Biotechnology     Open Access  
Journal of Agricultural, Biological & Environmental Statistics     Hybrid Journal   (Followers: 11)
Journal of Amino Acids     Open Access   (Followers: 4)
Journal of Anatomy     Hybrid Journal   (Followers: 7)
Journal of AOAC International     Full-text available via subscription   (Followers: 8)
Journal of Applied Biobehavioral Research     Hybrid Journal  
Journal of Applied Bioinformatics & Computational Biology     Hybrid Journal   (Followers: 5)
Journal of Applied Biological Sciences     Open Access   (Followers: 2)
Journal of Applied Biosciences     Open Access   (Followers: 1)
Journal of Applied Ichthyology     Hybrid Journal   (Followers: 6)
Journal of Applied Life Sciences International     Open Access  
Journal of Applied Phycology     Hybrid Journal   (Followers: 10)
Journal of Applied Virology     Open Access   (Followers: 4)
Journal of Aquatic Sciences     Full-text available via subscription   (Followers: 3)
Journal of Arachnology     Full-text available via subscription  
Journal of Asia-Pacific Biodiversity     Open Access  
Journal of Astrobiology & Outreach     Open Access   (Followers: 3)
Journal of Avian Biology     Hybrid Journal   (Followers: 24)
Journal of Basic Microbiology     Hybrid Journal   (Followers: 3)
Journal of Bio-Science     Open Access   (Followers: 3)
Journal of Biobased Materials and Bioenergy     Full-text available via subscription  
Journal of Biodiversity Management & Forestry     Hybrid Journal   (Followers: 6)
Journal of Bioenergetics and Biomembranes     Hybrid Journal   (Followers: 1)
Journal of Biogeography     Hybrid Journal   (Followers: 45)
Journal of Bioinformatics and Computational Biology     Hybrid Journal   (Followers: 18)
Journal of Bioinformatics and Intelligent Control     Full-text available via subscription   (Followers: 2)
Journal of Bioinformatics and Sequence Analysis     Open Access   (Followers: 1)
Journal of Biological Control     Hybrid Journal   (Followers: 2)
Journal of Biological Dynamics     Open Access   (Followers: 1)
Journal of Biological Education     Hybrid Journal   (Followers: 2)
Journal of Biological Engineering     Open Access   (Followers: 3)
Journal of Biological Methods     Open Access  
Journal of Biological Physics     Hybrid Journal   (Followers: 1)
Journal of Biological Research - Thessaloniki     Open Access  
Journal of Biological Sciences     Open Access   (Followers: 5)
Journal of Biological Systems     Hybrid Journal   (Followers: 2)
Journal of Biology and Life Science     Open Access   (Followers: 2)
Journal of Biology, Agriculture and Healthcare     Open Access   (Followers: 11)
Journal of Biomechanics     Hybrid Journal   (Followers: 39)
Journal of Biomedical Education     Open Access   (Followers: 2)
Journal of Biomedical Informatics     Partially Free   (Followers: 16)
Journal of Biomedical Informatics : X     Open Access  
Journal of Biomedical Materials Research Part A     Hybrid Journal   (Followers: 3)
Journal of Biomedical Materials Research Part B : Applied Biomaterials     Hybrid Journal   (Followers: 2)
Journal of Biomedical Nanotechnology     Full-text available via subscription   (Followers: 3)
Journal of Biomedical Physics and Engineering     Open Access  
Journal of Biomedical Science and Engineering     Open Access   (Followers: 2)
Journal of Bionic Engineering     Hybrid Journal  
Journal of Bioresource Management     Open Access  
Journal of Biorheology     Hybrid Journal  
Journal of Biosafety and Biosecurity     Open Access  
Journal of Bioscience and Bioengineering     Full-text available via subscription   (Followers: 34)
Journal of Biosciences and Medicines     Open Access   (Followers: 3)
Journal of Biosocial Science     Hybrid Journal   (Followers: 5)
Journal of Bryology     Hybrid Journal   (Followers: 7)
Journal of Cell Biology     Full-text available via subscription   (Followers: 47)
Journal of Cell Communication and Signaling     Hybrid Journal  
Journal of Cell Death     Open Access   (Followers: 2)
Journal of Cell Science     Full-text available via subscription   (Followers: 18)
Journal of Cellular Biochemistry     Hybrid Journal   (Followers: 4)
Journal of Cellular Physiology     Hybrid Journal   (Followers: 7)
Journal of Cerebral Blood Flow & Metabolism     Hybrid Journal   (Followers: 2)
Journal of Chromatography B     Hybrid Journal   (Followers: 34)
Journal of Clinical Bioinformatics     Open Access   (Followers: 5)
Journal of Clinical Toxicology     Open Access   (Followers: 6)
Journal of Communications Technology and Electronics     Hybrid Journal   (Followers: 2)
Journal of Contemporary Physics (Armenian Academy of Sciences)     Hybrid Journal   (Followers: 10)
Journal of Crustacean Biology     Hybrid Journal   (Followers: 2)
Journal of Developmental Biology     Open Access   (Followers: 2)
Journal of Ecology and The Natural Environment     Open Access   (Followers: 4)
Journal of Education, Health and Sport     Open Access   (Followers: 4)
Journal of Electrical Bioimpedance     Open Access   (Followers: 2)
Journal of Electromyography and Kinesiology     Hybrid Journal   (Followers: 5)
Journal of Environment and Ecology     Open Access   (Followers: 10)
Journal of Environment and Sociobiology     Hybrid Journal  
Journal of Environmental Analysis and Progress     Open Access  
Journal of Environmental Radioactivity     Hybrid Journal   (Followers: 3)
Journal of Environmental Science and Natural Resources     Open Access   (Followers: 4)
Journal of Ethnobiology     Full-text available via subscription   (Followers: 4)
Journal of Ethnobiology and Ethnomedicine     Open Access  
Journal of Ethology     Hybrid Journal   (Followers: 3)
Journal of Evolutionary Biology     Hybrid Journal   (Followers: 26)
Journal of Evolutionary Biology Research     Open Access  
Journal of Experimental and Clinical Anatomy     Open Access   (Followers: 2)
Journal of Experimental Life Science     Open Access  
Journal of Experimental Marine Biology and Ecology     Hybrid Journal   (Followers: 40)
Journal of Fish Biology     Hybrid Journal   (Followers: 36)
Journal of Functional Biomaterials     Open Access   (Followers: 3)
Journal of Fungi     Open Access   (Followers: 3)
Journal of Genomics     Open Access   (Followers: 1)
Journal of Great Lakes Research     Hybrid Journal   (Followers: 7)
Journal of Green Science and Technology     Full-text available via subscription   (Followers: 2)
Journal of Health and Biological Sciences     Open Access   (Followers: 1)
Journal of Heredity     Hybrid Journal   (Followers: 3)
Journal of Huazhong University of Science and Technology [Medical Sciences]     Hybrid Journal  
Journal of Human Evolution     Hybrid Journal   (Followers: 18)
Journal of Hymenoptera Research     Open Access   (Followers: 3)
Journal of Ichthyology     Hybrid Journal   (Followers: 3)
Journal of Insect Behavior     Hybrid Journal   (Followers: 7)
Journal of Insect Biodiversity     Open Access   (Followers: 4)
Journal of Insect Conservation     Hybrid Journal   (Followers: 10)
Journal of Institute of Science and Technology     Open Access  
Journal of Integrated OMICS     Open Access  
Journal of Integrated Pest Management     Open Access   (Followers: 3)
Journal of Integrative Environmental Sciences     Hybrid Journal   (Followers: 4)
Journal of Intelligent Transportation Systems: Technology, Planning, and Operations     Hybrid Journal   (Followers: 4)
Journal of Invertebrate Pathology     Hybrid Journal   (Followers: 3)
Journal of Landscape Ecology     Open Access   (Followers: 18)
Journal of Law and the Biosciences     Open Access   (Followers: 4)
Journal of Leukocyte Biology     Open Access   (Followers: 2)
Journal of Life and Earth Science     Open Access  
Journal of Life Sciences Research     Open Access  
Journal of Lipid Research     Full-text available via subscription   (Followers: 6)
Journal of Lipids     Open Access  
Journal of Luminescence     Hybrid Journal   (Followers: 4)
Journal of Mammalian Evolution     Hybrid Journal   (Followers: 7)
Journal of Mammalian Ova Research     Full-text available via subscription  
Journal of Mammalogy     Full-text available via subscription   (Followers: 13)
Journal of Mammary Gland Biology and Neoplasia     Hybrid Journal   (Followers: 1)
Journal of Marine and Aquatic Sciences     Open Access   (Followers: 1)
Journal of Marine Biology     Open Access   (Followers: 16)
Journal of Mathematical Biology     Hybrid Journal   (Followers: 9)
Journal of Mechanics in Medicine and Biology     Hybrid Journal  
Journal of Medical Primatology     Hybrid Journal   (Followers: 1)
Journal of Medical Toxicology     Hybrid Journal   (Followers: 6)
Journal of Medicinal Botany     Open Access  
Journal of Medicine and Philosophy     Hybrid Journal   (Followers: 8)
Journal of Melittology     Open Access   (Followers: 1)
Journal of Membrane Biology     Hybrid Journal   (Followers: 1)
Journal of Membrane Computing     Hybrid Journal  
Journal of Membrane Science     Hybrid Journal   (Followers: 25)
Journal of Molecular Biology     Hybrid Journal   (Followers: 45)
Journal of Molecular Biology Research     Open Access   (Followers: 3)
Journal of Molecular Catalysis B: Enzymatic     Hybrid Journal   (Followers: 1)
Journal of Molecular Cell Biology     Hybrid Journal   (Followers: 15)
Journal of Molecular Evolution     Hybrid Journal   (Followers: 6)
Journal of Molecular Signaling     Open Access  
Journal of Molecular Structure     Hybrid Journal   (Followers: 7)
Journal of Molluscan Studies     Hybrid Journal   (Followers: 1)
Journal of Muscle Research and Cell Motility     Hybrid Journal   (Followers: 1)
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 3)
Journal of Nanoparticles     Open Access   (Followers: 3)
Journal of Natural History     Hybrid Journal   (Followers: 11)
Journal of Natural Products     Hybrid Journal   (Followers: 19)
Journal of Natural Science, Biology and Medicine     Open Access   (Followers: 3)
Journal of Natural Sciences and Mathematics Research     Open Access  
Journal of Natural Sciences Research     Open Access   (Followers: 4)
Journal of Negative Results in BioMedicine     Open Access  
Journal of Nematology     Open Access   (Followers: 1)
Journal of Neuroscience and Behavioral Health     Open Access   (Followers: 1)
Journal of New Results in Science     Open Access  
Journal of New Seeds     Hybrid Journal  
Journal of Nucleic Acids     Open Access   (Followers: 1)
Journal of Parasitology     Full-text available via subscription   (Followers: 13)
Journal of Parasitology and Vector Biology     Open Access   (Followers: 2)
Journal of Pharmacological and Toxicological Methods     Hybrid Journal   (Followers: 7)
Journal of Phycology     Hybrid Journal   (Followers: 6)
Journal of Physics D : Applied Physics     Hybrid Journal   (Followers: 13)
Journal of Physics: Condensed Matter     Hybrid Journal   (Followers: 6)
Journal of Physics: Conference Series     Open Access   (Followers: 2)
Journal of Phytopathology     Hybrid Journal   (Followers: 2)
Journal of Plankton Research     Hybrid Journal   (Followers: 2)
Journal of Plant Ecology     Hybrid Journal   (Followers: 20)
Journal of Plant Pathology     Hybrid Journal  
Journal of Plasma Physics     Hybrid Journal   (Followers: 22)
Journal of Pollination Ecology     Open Access  
Journal of Porphyrins and Phthalocyanines     Hybrid Journal   (Followers: 2)
Journal of Progressive Research in Biology     Open Access   (Followers: 1)
Journal of Proteome Research     Hybrid Journal   (Followers: 12)
Journal of Proteomics     Hybrid Journal   (Followers: 10)
Journal of Purdue Undergraduate Research     Open Access   (Followers: 1)
Journal of Radiation Research and Applied Sciences     Open Access   (Followers: 2)
Journal of Risk Research     Hybrid Journal   (Followers: 9)
Journal of Science and Application Technology     Open Access  
Journal of Science of the University of Kelaniya Sri Lanka     Open Access  
Journal of Seed Science     Open Access   (Followers: 1)
Journal of Signal Transduction     Open Access   (Followers: 2)
Journal of Stem Cell Research & Therapy     Open Access   (Followers: 4)
Journal of Stem Cell Research and Tissue Engineering     Open Access  
Journal of Stored Products Research     Hybrid Journal  
Journal of Structural and Functional Genomics     Hybrid Journal   (Followers: 1)
Journal of Structural Biology     Hybrid Journal   (Followers: 5)
Journal of Structural Biology : X     Open Access  

  First | 1 2 3 4 5 6 7 8 | Last

Similar Journals
Journal Cover
Journal of Communications Technology and Electronics
Journal Prestige (SJR): 0.273
Citation Impact (citeScore): 1
Number of Followers: 2  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1555-6557 - ISSN (Online) 1064-2269
Published by Springer-Verlag Homepage  [2570 journals]
  • Celebrating the 100th Birthday of Boris Zakharovich Katsenelenbaum
           (26.11.1919–26.04.2015)
    • PubDate: 2019-11-01
       
  • Axial and Helical Metaparticles of Pulse Wave Fields
    • Abstract: Abstract—The properties of axial and helical metaparticles of pulse wave fields are presented. An example of emission of such metaparticles by an aperture source is considered. The field width and the energy density of a fundamental (zero) metaparticle in the far field of the radiating aperture are calculated.
      PubDate: 2019-11-01
       
  • Two-Dimensional Periodic Dual-Polarized Over Wave Region Antenna Array
    • Abstract: The two-dimensional periodic dual-polarized antenna array in the form of a nonuniform multiconductor line of square cross-section conductors is proposed and studied. Using the approximate theory, matching characteristics of the two-conductor line with three different laws of impedance variation are studied and the optimum law is found. Electrodynamic modeling of an infinite two-dimensional periodic array of these elements is carried out using the finite element method at different scanning modes. Using a numerical experiment, the possibility of implementing the over wave region matching mode is demonstrated for arrays of 144 (12 × 12) and 576 (24 × 24) elements: for the array of 576 elements, the working bandwidth in the cophased mode was 1 : 34; when scanning in the sector of 90°, more than 1 : 15.
      PubDate: 2019-11-01
       
  • On a Method for Measuring Methane Concentration on Extended Atmospheric
           Paths Using a Remote Gas Analyzer with a Powerful Raman Amplifier
    • Abstract: Abstract—The paper presents the results of methane concentration measurements on extended horizontal and vertical paths in the Earth’s atmosphere using a laser-generated remote gas analyzer based on a two-stage Raman amplifier with an output power of about 3 W in quasi-continuous mode with linear-frequency modulation of the laser and distributed feedback. An empirical expression of the weight function for anomalous gas distribution is obtained with a maximum concentration at a height of ~700 m and an anomalously low concentration at heights above 1000 m. This distribution agrees well with the experimental data obtained for a situational plan with additional methane emission sources. During measurements, the water absorption line was detected, which strongly depends on atmospheric humidity and can be used to refine weather data and ecological conditions.
      PubDate: 2019-11-01
       
  • Using the Method of Base Components for a Heuristic Solution to the
           Diffraction Problem on a Half-Plane with Nonideal Boundary Conditions
    • Abstract: Abstract—Using the method of base components, a heuristic solution to the diffraction problem on a semitransparent half-plane has been determined. The heuristic formulas have been verified via numerical solution. We have a semitransparency function for describing the transformation of the heuristic formulas upon variation in the transparency parameter of a scatterer.
      PubDate: 2019-11-01
       
  • Yttrium Iron Garnet Thickness Influence on the Spin Pumping in the Bulk
           Acoustic Wave Resonator
    • Abstract: The features of phonon–magnon interconversion in acoustic resonator determine the efficiency of spin pumping from YIG into Pt that may be detected electrically through the inverse spin Hall effect (ISHE). Based on the methods developed in previous works for calculating resonator structures with a piezoelectric (ZnO) and a magnetoelastic layer in contact with the heavy metal (YIG/Pt), we present the results of numerical calculations of YIG film thickness influence on acoustically driven spin waves. We obtain some YIG film thickness regions with various behavior of dc ISHE voltage UISHE. At micron and submicron thicknesses, the higher spin wave resonance (SWR) modes (both even and odd) can be generated with efficiency comparable and even exceeding that of the main mode. The absolute maximum of UISHE is achieved at the thickness about s1 ≈ 208 nm under the excitation of the first SWR.
      PubDate: 2019-11-01
       
  • Coupled Plasmon Oscillations in a Cluster Consisting of Three Silver
           Nanocylinders with Different Diameters
    • Abstract: 2D problem of the diffraction of the TM plane electromagnetic wave by a cluster consisting of three self-similar silver nanocylinders with different sizes is considered. Rigorous numerical procedures are used to study quasi-static plasmon resonances in such a cluster. Frequency characteristics of the scattering cross section and spatial structure of the field in the vicinity of the cylinders are calculated for different angles of incidence of the plane wave, self-similarity coefficients, and diameters of cylinders. It is shown that an increase in the distance between the cylinders is accompanied by degeneration of the resonances of scattering cross section. When real loss of silver is taken into account, electric field at the exit of the cluster cannot be amplified by a factor of greater than 10.
      PubDate: 2019-11-01
       
  • Spectra of a Photonic Crystal Containing a Layer with a High Dielectric
           Constant
    • Abstract: Abstract—The features of the transmission spectra of a one-dimensional photonic crystal are studied, in which the dielectric constant of one of the two layers in the structural period is many times greater than the permittivity of the other. The spectra of a finite defect-free structure, an inversion-defect structure, and a symmetric microcavity structure are considered. The authors demonstrate the possibility of controlling the width of the photonic band gap using an electric field, as well as achieving a very narrow spectral line of the defect mode and an ultrahigh degree of radiation localization at the defect.
      PubDate: 2019-11-01
       
  • Electrodynamics of Inhomogeneous 2D Periodic Media
    • Abstract: A new method is proposed to represent electromagnetic field in inhomogeneous 2D periodic medium (PM) as a discrete set of amplitude vectors (AVs) each of which contains amplitudes of spatial harmonics of the field scattered by a particular particle. A scattering operator of a particle is introduced to establish a relationship of the amplitudes of harmonics of the scattered and excitation fields, and an external source is introduced to consider the scattering field that is not related to the excitation field of a particle. An exact nonlocal equation is derived for AVs to describe propagation of electromagnetic waves in PM, and an approximate localized difference equation (an analog of the wave equation in continuous medium) is obtained. Quadratic relationships are obtained for AVs: theorem on active power, Lorentz lemma, and reciprocity theorem. A problem of excitation of homogeneous PM by an external source is solved, and the Green function of PM is obtained. Boundary conditions for AV are introduced at the PM defects that disturb periodicity. A method to formulate and solve the boundary-value problem for AVs in PM with defects is proposed. Analytical solutions to canonical boundary-value problems of PM electrodynamics (eigenwaves of homogeneous PM, normal modes of a cavity, and eigenwaves of an infinite waveguide) are considered. Construction of efficient numerical algorithms for solution of boundary-value problems in electrodynamics of inhomogeneous PM is discussed.
      PubDate: 2019-11-01
       
  • Edge Catastrophes in Diffraction Problems
    • Abstract: Abstract—The application of the wave theory of edge catastrophes to the asymptotic solution of diffraction problems on bodies with curvilinear edges is considered. As an example, the diffraction of a converging scalar wave on a curvilinear ideally conducting screen in a homogeneous medium is studied, leading to the formation of C4 and K4, 2 edge catastrophes.
      PubDate: 2019-11-01
       
  • The Method of Integral Equations in the Theory of Antenna Arrays
    • Abstract: The method of mathematical simulation of antenna arrays is considered. It is based on the investigation of integral equations and can be applied to a wide range of radiators.
      PubDate: 2019-11-01
       
  • Investigation and Evaluation of the Effect of Silicon Layer and Its
           Comparison with Water Bolus in Designing Microstrip Antenna for
           Hyperthermia Applications
    • Abstract: In this paper, the main concern is the designing of microstrip structure for Hyperthermia and tissue heating. The purpose of this antenna designing is the capacity of doing an action in 2.24 GHz Frequency and the usage of Silicone tissue in spite of water bolus to decrease the burn percentage on skin to the least degree and solve the problems caused by the water bolus tissue. The function of the antenna by Moment Method and the frequency analysis method is simulated and developed through several stages and biologic tissue which includes three layers (skin, fat, muscle). The improvement in this antenna is the transformation of heating to the upper part of skin and fat layers. The results have been evaluated in four shapes, water bolus, water bolus—silicon, silicon—water bolus, and silicon alone. In first three shapes, the energy is not capable to permeate into the tissue in higher depths; and, it will stay in the fat tissue. Only when silicon has been used, the energy will permeate into the muscular tissue without any damages to the other body tissues. The size of the antenna (0.84 × 45 × 70 mm) and the coaxial 50 Ω has been used for feeding.
      PubDate: 2019-11-01
       
  • Low Elevation Angle Estimation Using an Iterative Array Processing Method
    • Abstract: — Multipath phenomenon reduces the performance of elevation angle estimation, intensively. In this study, a precise even symmetry relation and novel iterative array processing method have been presented based on the fixed beam method for estimating the elevation angle of low-altitude targets in specular and diffuse multipath environment. We propose an iterative beamforming process for retaining antenna aperture with precise even symmetry to eliminate multipath. The Kalman filter (KF) prediction have been used to reduce the computational load of the proposed method, and the frequency diversity and KF estimation to smooth sudden fluctuations in angle estimation. The proposed method estimates the elevation angle with very high precision as shown in simulation results in the multipath environment without the need for any advance knowledge.
      PubDate: 2019-11-01
       
  • Performance Prediction of a Quantum Well Infrared Photodetector Using
           GeSn/SiGeSn Structure
    • Abstract: — QWIP using group IV elements have created more interest among researchers for its potential application in optical communication as well as in optical interconnects. This paper presents modeling and theoretical analysis of Sn-based tensile strained type I direct band gap QWIP in which the active region has a multiple quantum well structure formed with Ge0.92Sn0.08 quantum wells separated by Si0.11Ge0.7Sn0.19 barriers. The structure reported by V. Ryzhii et al. has been reproduced and the parameters like responsivity, power density and the dark current density have been analytically calculated. A comprehensive comparison of responsivity and power density of this proposed structure with the existing QWIP structure made of GaAs/InGaAs is reported here. An improvement in the field of responsivity is observed with the proposed model. The reduction of threshold power density corresponds to an effective operation of the QWIPs in incident infrared radiation. The intersubband electron transition and tunneling electron injection effects are considered here to predict a better performance of the proposed structure operated in infrared region.
      PubDate: 2019-11-01
       
  • Ionospheric Decontamination Method Based on Optimization Criteria in
           Over-the-Horizon Radar
    • Abstract: — Over-the-horizon (OTH) radar is important equipment for wide-area surveillance; it has several uses, including aircraft tracking, ship and missile detecting, and remote sensing of the ocean surface. OTH radar uses high frequency electromagnetic wave which propagates by means of refraction within ionosphere; it can provide large range coverage. But this will cause phase contamination due to the unstable movement of the ionosphere. The spectrum of sea clutter and target will be expanded by the ionospheric contamination in the Doppler domain, which will cause the ship target more difficult to separate from the clutter and even buried in the clutter. A new decontamination method is proposed to solve this problem. By analyzing the sea clutter signal model, the proposed method designs an ideal optimized matrix and then uses optimization criteria to estimate phase contamination. Based on the real data, the effectiveness of the new method was validated and compared against other methods.
      PubDate: 2019-11-01
       
  • New Functional Capabilities of Microwave Interferometry When Using
           Metastructure as a Tunable Beam Splitter
    • Abstract: — It is experimentally shown that the microwave metainterferometer with a metastructure (metasurface or metaatom) as a tunable beam splitter possesses the unique possibility to specify selective magnetic and electric tuning of multiband filtration of electromagnetic waves. The investigation results are shown concerning the interferogram of a modified metainterferometer based upon the waveguide tee junctions in which the metastructure contains a ferrite plate or a structure made of conducting resonant elements compatible with the controlling elements or their combination with ferrite. The dependences of the shape, width, intensity, and frequency of the interference band on the value and sign of a magnetostatic field, on the relative position of ferromagnetic resonance and the band, and on the electric voltage on the varactors included in the discontinuities of elements. We have experimental results that open new methods and approaches in the design of switchable and tunable multiband microwave filters needed in multifunctional multichannel telecommunication systems.
      PubDate: 2019-11-01
       
  • Acquisition and Analysis of Multi-Global Navigation Satellite System
           Signals Based on Fast Fourier Transform
    • Abstract: — This paper presents an essential technique for acquiring multi-GNSS signals using FFT. The fundamental approach of multi-GNSS satellite navigation is that the navigation information transmitted with the help of stand-alone GNSS system of numerous constellations is acquired by the receiver. The reason for the acquisition is to apprehend how many total numbers of satellites are currently visible to the user segment; also, the acquisition must determine the code phase and frequency of satellite signals. Although, there are three search domains, which are Doppler frequency, code phase, and code identification, in the acquisition processing, the emphasis of this paper will be on the search of the code phase. FFT based acquisition can decrease acquisition time of DSSS signals due to an increase in the power of DSP chips. The use of FFT based algorithms to perform acquisition of Direct Sequence Spread Spectrum (DSSS) is still the hot topic of research. The main purpose of this study is the analysis of the Multi-GNSS signal acquisition process using the Fast Fourier Transform (FFT) method. Based on MATLAB software platform; GPS, GLONASS, and BeiDou signals are acquired from the real IF signal records of GPS, GLONASS, and BeiDou. The output results of the FFT based acquisition are presented and discussed.
      PubDate: 2019-11-01
       
  • Promotion of Improved Discrete Polynomial-Phase Transform Method for Phase
           Parameters Estimation of Linear Frequency Modulation Signal
    • Abstract: The discrete polynomial-phase transform (DPT) method estimate chirp rate and central frequency of LFM signal based on sequential estimation of polynomial phase parameters. DPT method which has been developed by an iterative approach as Improved DPT method uses nonlinear least squares (NLS) technique to estimate phase parameters of the LFM signal. NLS have high computational load. In order to promote the precision of estimation and reduce the computational load in Improved DPT method, combined technique is proposed and used which provides an initial estimation of frequency interval based on NLS criterion in single-exponential mode and using random basis functions method.
      PubDate: 2019-11-01
       
  • Speaker Modeling Using Emotional Speech for More Robust Speaker
           Identification
    • Abstract: — Automatic identity recognition in fast, reliable and non-intrusive way is one of the most challenging topics in digital world of today. A possible approach to identity recognition is the identification by voice. Characteristics of speech relevant for automatic speaker recognition can be affected by external factors such as noise and channel distortions, but also by speaker-specific conditions—emotional or health states. The improvement of a speaker recognition system by different model training strategies are addressed in this paper in order to obtain the best performance of the system with only a limited amount of neutral and emotional speech data. The models adopted are a Gaussian Mixture Model and i-vectors whose inputs are Mel Frequency Cepstral Coefficients, and the experiments have been conducted on the Russian Language Affective speech database. The results show that the appropriate use of emotional speech in speaker model training improves the robustness of a speaker recognition system – both when tested on neutral and emotional speech.
      PubDate: 2019-11-01
       
  • Features of Constructing an Orthonormal Basis Based on Atomic Functions as
           Applied to Solving Boundary Value Electrodynamics Problems for Regions of
           Complex Shape
    • Abstract: — A method for orthonormalizing atomic functions is proposed and substantiated. The efficiency of using a basic system to solve a number of boundary value electrodynamics problems is shown. Numerical experiment and analysis of the physical results showed that the R-functions method combined with basis functions is universal for waveguides and resonators of arbitrary shape.
      PubDate: 2019-11-01
       
 
 
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