95 research outputs found

    Basis Pursuit Receiver Function

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    Receiver functions (RFs) are derived by deconvolution of the horizontal (radial or transverse) component of ground motion from the vertical component, which segregates the PS phases. Many methods have been proposed to employ deconvolution in frequency as well as in time domain. These methods vary in their approaches to impose regularization that addresses the stability problem. Here, we present application of a new time-domain deconvolution technique called basis pursuit deconvolution (BPD) that has recently been applied to seismic exploration data. Unlike conventional deconvolution methods, the BPD uses an L1 norm constraint on model reflectivity to impose sparsity. In addition, it uses an overcomplete wedge dictionary based on a dipole reflectivity series to define model constraints, which can achieve higher resolution than that obtained by the traditional methods. We demonstrate successful application of BPD based RF estimation from synthetic data for a crustal model with a near-surface thin layer of thickness 5, 7, 10, and 15 km. The BPD can resolve these thin layers better with much improved signal-to-noise ratio than the conventional methods. Finally, we demonstrate application of the BPD receiver function (BPRF) method to a field dataset from Kutch, India, where near-surface sedimentary layers are known to be present. The BPRFs are able to resolve reflections from these layers very well.Jackson Chair funds at the Jackson School of Geosciences, University of Texas, AustinCouncil of Scientific and Industrial Research twelfth five year plan project at the Council of Scientific and Industrial Research National Geophysical Research Institute (CSIR-NGRI), HyderabadInstitute for Geophysic

    Prediction-based protein engineering of domain I of Cry2A entomocidal toxin of Bacillus thuringiensis for the enhancement of toxicity against lepidopteran insects

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    Issues relating to sustenance of the usefulness of genetically modified first generation Bt crop plants in the farmer’s field are of great concern for crop scientists. Additional biotechnological strategies need to be in place to safeguard the possibility for yield loss of Bt crop by other lepidopteran insects that are insensitive to the Cry1A toxin, and also against the possibility for emergence of resistant insects. In this respect, Cry2A toxin has figured as a prospective candidate to be the second toxin to offer the required protection along with Cry1A. In the present study, the entomocidal potency of Cry2A toxin was enhanced through knowledge-based protein engineering of the toxin molecule. Deletion of 42 amino acid residues from the N-terminal end of the peptide followed by the replacement of Lys residues by nonpolar amino acids in the putative transmembrane region including the introduction of Pro resulted in a 4.1–6.6-fold increase in the toxicity of the peptide against three major lepidopteran insect pests of crop plants

    Preliminary studies of surface water quality in Damodar River basin (West Bengal, India)

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    The purpose of the research was to study the main parameters of the chemical composition of surface water and its quality in the Damodar River basin near the Durgapur city where the surface water is used for water supply of the local community. During fieldwork water of the Damodar River, its tributaries (Tamla River and small streams - receivers of industrial wastewater and drainage water) and the Maithon Reservoir was sampled from the layer 0.1-0.5 m. Preliminary studies have shown that the main pollutants in the study area are organic compounds, ammonium, phosphate and fluoride ions. Deterioration of water quality in some sampling points is connected with a low content of dissolved oxygen and high concentrations of nitrite, chloride and sulfate ions

    Preliminary studies of surface water quality in Damodar River basin (West Bengal, India)

    Get PDF
    The purpose of the research was to study the main parameters of the chemical composition of surface water and its quality in the Damodar River basin near the Durgapur city where the surface water is used for water supply of the local community. During fieldwork water of the Damodar River, its tributaries (Tamla River and small streams - receivers of industrial wastewater and drainage water) and the Maithon Reservoir was sampled from the layer 0.1-0.5 m. Preliminary studies have shown that the main pollutants in the study area are organic compounds, ammonium, phosphate and fluoride ions. Deterioration of water quality in some sampling points is connected with a low content of dissolved oxygen and high concentrations of nitrite, chloride and sulfate ions

    Continuous and Discrete Time Signals and Systems

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    This textbook presents an introduction to the fundamental concepts of continuous-time (CT) and discrete-time (DT) signals and systems, treating them separately in a pedagogical and self-contained manner. Emphasis is on the basic signal processing principles, with underlying concepts illustrated using practical examples from signal processing, multimedia communications, and bioinformatics. Following introductory chapters, the text is separated into two parts. Part I covers the theories, techniques, and applications of CT signals and systems and Part II discusses these topics for DT, so that the two can be taught independently or together. Accompanying the book is a CD-ROM containing MATLAB code, audio clips, images, interactive programs, and signal animations. With over 300 illustrations, 285 worked examples and 385 homework problems, this textbook is an ideal introduction to the subject for undergraduates in electrical and computer engineering. Further resources, including solutions for instructors, are available online at www.cambridge.org/9780521854559

    Computer-Aided Design of a Switchable True Time Delay (TTD) Line With Shunt Open-Stubs

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    Continuous and discrete time signals and systems: (with CD-ROM)

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    Alternative Approach of Developing Optical Binary Adder Using Reversible Peres Gates

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    All-optical devices will play a very significant and crucial role in the modern all-optical network by eliminating the bottleneck of opto-electro-opto- (O-E-O-) conversion. Unfortunately, the conventional logic gates lose information at the output, and the states of the outputs cannot give any credible impressions of the states of the inputs. In this article, at first, the authors have proposed a method of designing an optical three-input-three-output reversible Peres gate. Authors have deployed polarization switching characteristic of Semiconductor Optical Amplifier (SOA) for designing this circuit. The authors have also proposed a method of designing an optical reversible full adder, using two such Peres gates and subsequently a data recovery circuit which can recover the input data of the adder. The authors have chosen frequency encoded data for processing the operation. The proposed scheme has been verified by simulation results
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