Showing papers by "Indian Institute of Technology, Jodhpur published in 2015"

A critical review of detection and classification of power quality events

Abstract: Requirement of green supply with higher quality has been consumers’ demand around the globe The electrical power system is expected to deliver undistorted sinusoidal rated voltage and current continuously at rated frequency to the consumers This paper presents a comprehensive review of signal processing and intelligent techniques for automatic classification of the power quality (PQ) events and an effect of noise on detection and classification of disturbances It is intended to provide a wide spectrum on the status of detection and classification of PQ disturbances as well as an effect of noise on detection and classification of PQ events to the researchers, designers and engineers working on power quality More than 150 research publications on detection and classification techniques of PQ disturbances have been critically examined, classified and listed for quick reference

A Compact Koch Fractal UWB MIMO Antenna With WLAN Band-Rejection

Abstract: In this letter, a compact octagonal shaped fractal ultrawideband multiple-input–multiple-output antenna is presented, and its characteristics are investigated In order to achieve the desired miniaturization and wideband phenomena, self-similar and space filling properties of Koch fractal geometry are used in the antenna design These fractal monopoles are placed orthogonal to each other for good isolation Moreover, grounded stubs are used in the geometry to provide further improvement in the isolation The band rejection phenomenon in wireless local area network band is achieved by etching a C-shaped slot from the monopole of the antenna The proposed antenna has compact dimensions of $45~\hbox{mm} \times 45~\hbox{mm}$ and exhibits quasi-omnidirectional radiation pattern In addition, it shows an impedance bandwidth ( ${{\rm S}_{11}}\! ) from 2 to 106 GHz with isolation better than 17 dB over the entire ultra-wideband range Diversity performance is also evaluated in terms of envelope correlation coefficient and capacity loss The measured results show good agreement with the simulated ones

Tyrosine- and tryptophan-coated gold nanoparticles inhibit amyloid aggregation of insulin.

Abstract: Here, we have strategically synthesized stable gold (AuNPsTyr, AuNPsTrp) and silver (AgNPsTyr) nanoparticles which are surface functionalized with either tyrosine or tryptophan residues and have examined their potential to inhibit amyloid aggregation of insulin. Inhibition of both spontaneous and seed-induced aggregation of insulin was observed in the presence of AuNPsTyr, AgNPsTyr, and AuNPsTrp nanoparticles. These nanoparticles also triggered the disassembly of insulin amyloid fibrils. Surface functionalization of amino acids appears to be important for the inhibition effect since isolated tryptophan and tyrosine molecules did not prevent insulin aggregation. Bioinformatics analysis predicts involvement of tyrosine in H-bonding interactions mediated by its C=O, –NH2, and aromatic moiety. These results offer significant opportunities for developing nanoparticle-based therapeutics against diseases related to protein aggregation.

Controlled bidirectional remote state preparation in noisy environment: a generalized view

Abstract: It is shown that a realistic controlled bidirectional remote state preparation is possible using a large class of entangled quantum states having a particular structure. Existing protocols of probabilistic, deterministic and joint remote state preparation are generalized to obtain the corresponding protocols of controlled bidirectional remote state preparation (CBRSP). A general way of incorporating the effects of two well-known noise processes, the amplitude-damping and phase-damping noise, on the probabilistic CBRSP process is studied in detail by considering that noise only affects the travel qubits of the quantum channel used for the probabilistic CBRSP process. Also indicated is how to account for the effect of these noise channels on deterministic and joint remote state CBRSP protocols.

Deep Structured Models For Group Activity Recognition

Abstract: This paper presents a deep neural-network-based hierarchical graphical model for individual and group activity recognition in surveillance scenes. Deep networks are used to recognize the actions of individual people in a scene. Next, a neural-network-based hierarchical graphical model refines the predicted labels for each class by considering dependencies between the classes. This refinement step mimics a message-passing step similar to inference in a probabilistic graphical model. We show that this approach can be effective in group activity recognition, with the deep graphical model improving recognition rates over baseline methods.

Analysis of Food Pairing in Regional Cuisines of India.

Abstract: Any national cuisine is a sum total of its variety of regional cuisines, which are the cultural and historical identifiers of their respective regions. India is home to a number of regional cuisines that showcase its culinary diversity. Here, we study recipes from eight different regional cuisines of India spanning various geographies and climates. We investigate the phenomenon of food pairing which examines compatibility of two ingredients in a recipe in terms of their shared flavor compounds. Food pairing was enumerated at the level of cuisine, recipes as well as ingredient pairs by quantifying flavor sharing between pairs of ingredients. Our results indicate that each regional cuisine follows negative food pairing pattern; more the extent of flavor sharing between two ingredients, lesser their co-occurrence in that cuisine. We find that frequency of ingredient usage is central in rendering the characteristic food pairing in each of these cuisines. Spice and dairy emerged as the most significant ingredient classes responsible for the biased pattern of food pairing. Interestingly while individual spices contribute to negative food pairing, dairy products on the other hand tend to deviate food pairing towards positive side. Our data analytical study highlighting statistical properties of the regional cuisines, brings out their culinary fingerprints that could be used to design algorithms for generating novel recipes and recipe recommender systems. It forms a basis for exploring possible causal connection between diet and health as well as prospection of therapeutic molecules from food ingredients. Our study also provides insights as to how big data can change the way we look at food.

A review of distribution static compensator

Abstract: This paper presents a comprehensive review of the distribution static compensator employed for harmonic filtering, power factor correction, neutral current compensation, and load balancing in the distribution network. The intention of this review is to provide a wide spectrum on architecture, topologies, and control techniques to the researchers, designers, and engineers working on power quality improvement. More than 100 research publications on the topologies, configuration, control techniques, and applications of distribution static compensator have been thoroughly reviewed and classified for quick reference.

Immobilized laccase mediated dye decolorization and transformation pathway of azo dye acid red 27

Abstract: Laccases have good potential as bioremediating agents and can be used continuously in the immobilized form like many other enzymes. In the present study, laccase from Cyathus bulleri was immobilized by entrapment in Poly Vinyl Alcohol (PVA) beads cross-linked with either nitrate or boric acid. Immobilized laccase was used for dye decolorization in both batch and continuous mode employing a packed bed column. The products of degradation of dye Acid Red 27 were identified by LC MS/MS analysis. The method led to very effective (90%) laccase immobilization and also imparted significant stability to the enzyme (more than 70% after 5 months of storage at 4°C). In batch decolorization, 90-95% decolorization was achieved of the simulated dye effluent for up to 10–20 cycles. Continuous decolorization in a packed bed bioreactor led to nearly 90% decolorization for up to 5 days. The immobilized laccase was also effective in decolorization and degradation of Acid Red 27 in the presence of a mediator. Four products of degradation were identified by LC-MS/MS analysis. The immobilized laccase in PVA-nitrate was concluded to be an effective agent in treatment of textile dye effluents.

New-physics signals of a model with a vector-singlet up-type quark

Abstract: The VuQ model involves the addition of a vector isosinglet up-type quark to the standard model. In this model the full Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix is $4\ifmmode\times\else\texttimes\fi{}3$. Using present flavor-physics data, we perform a fit to this full CKM matrix, looking for signals of new physics (NP). We find that the VuQ model is very strongly constrained. There are no hints of NP in the CKM matrix, and any VuQ contributions to loop-level flavor-changing $b\ensuremath{\rightarrow}s$, $b\ensuremath{\rightarrow}d$ and $s\ensuremath{\rightarrow}d$ transitions are very small. There can be significant enhancements of the branching ratios of the flavor-changing decays $t\ensuremath{\rightarrow}uZ$ and $t\ensuremath{\rightarrow}cZ$, but these are still below present detection levels.

Deep structured models for group activity recognition

Abstract: This thesis presents a deep neural-network-based hierarchical graphical model for individual and group activity recognition in surveillance scenes. As the first step, deep networks are used to recognize activities of individual people in a scene. Then, a neural network-based hierarchical graphical model refines the predicted labels for each activity by considering dependencies between different classes. Similar to the inference mechanism in a probabilistic graphical model, the refinement step mimics a message-passing encoded into a deep neural network architecture. We show that this approach can be effective in group activity recognition. The deep graphical model improves recognition rates over baseline methods.

A quantum-information theoretic analysis of three-flavor neutrino oscillations

Abstract: Correlations exhibited by neutrino oscillations are studied via quantum-information theoretic quantities. We show that the strongest type of entanglement, genuine multipartite entanglement, is persistent in the flavor changing states. We prove the existence of Bell-type nonlocal features, in both its absolute and genuine avatars. Finally, we show that a measure of nonclassicality, dissension, which is a generalization of quantum discord to the tripartite case, is nonzero for almost the entire range of time in the evolution of an initial electron-neutrino. Via these quantum-information theoretic quantities, capturing different aspects of quantum correlations, we elucidate the differences between the flavor types, shedding light on the quantum-information theoretic aspects of the weak force.

Binary group III-nitride based heterostructures: band offsets and transport properties

Abstract: In the last few years, there has been remarkable progress in the development of group III-nitride based materials because of their potential application in fabricating various optoelectronic devices such as light emitting diodes, laser diodes, tandem solar cells and field effect transistors. In order to realize these devices, growth of device quality heterostructures are required. One of the most interesting properties of a semiconductor heterostructure interface is its Schottky barrier height, which is a measure of the mismatch of the energy levels for the majority carriers across the heterojunction interface. Recently, the growth of non-polar III-nitrides has been an important subject due to its potential improvement on the efficiency of III-nitride-based opto-electronic devices. It is well known that the c-axis oriented optoelectronic devices are strongly affected by the intrinsic spontaneous and piezoelectric polarization fields, which results in the low electron-hole recombination efficiency. One of the useful approaches for eliminating the piezoelectric polarization effects is to fabricate nitride-based devices along non-polar and semi-polar directions. Heterostructures grown on these orientations are receiving a lot of focus due to enhanced behaviour. In the present review article discussion has been carried out on the growth of III-nitride binary alloys and properties of GaN/Si, InN/Si, polar InN/GaN, and nonpolar InN/GaN heterostructures followed by studies on band offsets of III-nitride semiconductor heterostructures using the x-ray photoelectron spectroscopy technique. Current transport mechanisms of these heterostructures are also discussed.

Phytochemica: a platform to explore phytochemicals of medicinal plants

Abstract: Plant-derived molecules (PDMs) are known to be a rich source of diverse scaffolds that could serve as the basis for rational drug design. Structured compilation of phytochemicals from traditional medicinal plants can facilitate prospection for novel PDMs and their analogs as therapeutic agents. Atropa belladonna, Catharanthus roseus, Heliotropium indicum, Picrorhiza kurroa and Podophyllum hexandrum are important Himalayan medicinal plants, reported to have immense therapeutic properties against various diseases. We present Phytochemica, a structured compilation of 963 PDMs from these plants, inclusive of their plant part source, chemical classification, IUPAC names, SMILES notations, physicochemical properties and 3-dimensional structures with associated references. Phytochemica is an exhaustive resource of natural molecules facilitating prospection for therapeutic molecules from medicinally important plants. It also offers refined search option to explore the neighbourhood of chemical space against ZINC database to identify analogs of natural molecules at user-defined cut-off. Availability of phytochemical structured dataset may enable their direct use in in silico drug discovery which will hasten the process of lead identification from natural products under proposed hypothesis, and may overcome urgent need for phytomedicines. Compilation and accessibility of indigenous phytochemicals and their derivatives can be a source of considerable advantage to research institutes as well as industries. Database URL: home.iitj.ac.in/� bagler/webservers/Phytochemica

Power Quality Detection in Distribution System with Wind Energy Penetration Using Discrete Wavelet Transform

Abstract: This paper presents an approach for the detection and localisation of the power quality events associated with wind energy penetration into the distribution network. A standard IEEE 13 bus distribution network has been modified by adding wind and diesel generators for the case studies. The proposed test system is simulated in MATLAB/simulink environment. Voltage signals captured at nodes of the test system are used for power quality analysis. The harmonic detection has been carried out using Fast Fourier Transform and voltage sag, swell have been detected by voltage index calculated based on wavelet analysis. The unbalance in the system has been detected by the sequence components of voltage. The power quality disturbances associated with the events such as islanding, grid synchronization and outage of wind generators have been investigated. The detection of islanding, grid synchronization and outage has been proposed using sequence components of voltages measured.

Growth of residual stress-free ZnO films on SiO2/Si substrate at room temperature for MEMS devices

Abstract: ZnO thick Stress relaxed films were deposited by reactive magnetron sputtering on 2”-wafer of SiO2/Si at room temperature. The residual stress of ZnO films was measured by measuring the curvature of wafer using laser scanning method and found in the range of 0.18 x 109 to 11.28 x 109 dyne/cm2 with compressive in nature. Sputter pressure changes the deposition rates, which strongly affects the residual stress and surface morphologies of ZnO films. The crystalline wurtzite structure of ZnO films were confirmed by X-ray diffraction and a shift in (0002) diffraction peak of ZnO towards lower 2θ angle was observed with increasing the compressive stress in the films. The band gap of ZnO films shows a red shift from ∼3.275 eV to ∼3.23 eV as compressive stress is increased, unlike the stress for III-nitride materials. A relationship between stress and band gap of ZnO was derived and proposed. The stress-free growth of piezoelectric films is very important for functional devices applications.

A compact octagonal fractal UWB MIMO antenna with WLAN band‐rejection

Abstract: In this article, a compact octagonal-shaped fractal ultrawideband (UWB) multiple-input-multiple-output (MIMO) antenna is presented and its characteristics are investigated. The application of Koch fractal geometry at the edges of octagonal monopole provides desired miniaturization and wideband phenomena due to its self-similar and space filling properties. The two octagonal fractal antennas are placed orthogonal to each other and used to construct UWB MIMO antenna. An L-shaped stub is used in the ground plane of the geometry to provide an improvement in the isolation. The band rejection in wireless local area network band is achieved by etching a C-shaped slot from the monopole of the individual antenna. The compact dimension 40 × 25 mm2 of the antenna exhibits nearly omnidirectional radiation pattern, a low envelope correlation coefficient (<0.01), with good S-parameters over the entire UWB frequency range. The measured results show good agreement with the simulated one. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1919–1925, 2015

Detection of power quality events associated with grid integration of 100kW solar PV plant

Abstract: This paper presents a technique for the detection and localization of the power quality events associated with outage and grid synchronization of solar photovoltaic plant in distribution network. A standard IEEE 13 bus distribution network has been modified by adding 100kW solar photovoltaic plant. The proposed test system is simulated in MATLAB/simulink environment. Voltage signals captured at nodes of the test system are used for power quality analysis. The harmonic detection has been carried out using fast Fourier transform and the voltage sag, swell has been detected by voltage index calculated based on wavelet analysis. The unbalance in the voltage has been detected by sequence components of voltages. The power quality events associated with sudden change in the solar insolation have also been investigated. Detection and discrimination of synchronization, outage and sudden changes in solar insolation has been proposed using sequence components of voltages measured.

A novel image fusion framework for night-vision navigation and surveillance

Abstract: The night-vision image fusion plays a critical role in detecting targets and obstructions in low light or total darkness, which has great importance for pedestrian recognition, vehicle navigation, surveillance and monitoring applications. The central idea is to fuse low-light visible and infrared imagery into a single output. In this paper, we describe a new fusion framework for spatially registered visual and infrared images. The proposed framework utilizes the properties of fractal dimension and phase congruency in the non-subsampled contourlet transform (NSCT) domain. The proposed framework applies multiscale NSCT on visual and IR images to get low- and high-frequency bands. The varied frequency bands of the transformed images are then fused while exploiting their characteristics. Finally, the inverse NSCT is performed to get the fused image. The performance of the proposed framework is validated by extensive experiments on different scene imaginary, where the definite advantages are demonstrated subjectively and objectively.

Structure and Dynamics of Phospholipid Nanodiscs from All-Atom and Coarse-Grained Simulations

Abstract: We investigated structural and dynamical properties of nanodiscs comprising dimyristoylphosphatidylcholine (DMPC) lipids and major scaffold protein MSP1Δ(1–22) from human apolipoprotein A-1 using combined all-atom and coarse-grained (CG) molecular dynamics (MD) simulations. The computational efficiency of the Martini-CG force field enables the spontaneous self-assembly of lipids and scaffold proteins into stable nanodisc structures on time scales up to tens of microseconds. Subsequent all-atom and CG-MD simulations reveal that the lipids in the nanodisc have lower configurational entropy and higher acyl tail order than in a lamellar bilayer phase. These altered average properties arise from rather differential behavior of lipids, depending on their location in the nanodisc. Since the scaffold proteins exert constrictive forces from the outer rim of the disc toward its center, lipids at the center of the nanodisc are highly ordered, whereas annular lipids that are in contact with the MSP proteins are remar...

Schottky-contacted vertically self-aligned ZnO nanorods for hydrogen gas nanosensor applications

Abstract: Vertically well aligned ZnO nanorods (NRs) were grown on Si(100) substrate using RF magnetron sputtering technique. Scanning electron microscopy images confirms uniform distribution of NRs on 2 in. wafer with average diameter, height and density being ∼75 nm, ∼850 nm, and ∼1.5 × 1010 cm−2, respectively. X-ray diffraction reveals that the ZnO NRs are grown along c-axis direction with wurtzite crystal structure. Cathodoluminescence spectroscopy, which shows a single strong peak around 3.24 eV with full width half maxima 130 meV, indicates the high crystalline and optical quality of ZnO and very low defect density. Vertically aligned nanosensors were fabricated by depositing gold circular Schottky contacts on ZnO NRs. Resistance responses of nanosensors were observed in the range from 50 to 150 °C in 1% and 5% hydrogen in argon environment, which is below and above the explosive limit (4%) of hydrogen in air. The nanosensor's sensitivity increases from 11% to 67% with temperature from 50 to 150 °C and also s...

Sliding mode control of a bidirectional DC/DC converter with constant power load

Abstract: DC microgrid consists of cascaded power converters in which the constant power load behaviour of point-of-load converters poses challenging stability issues even if individual converters are stable. In this paper, a robust sliding mode controller has been proposed for DC/DC bidirectional buck-boost converter interfacing storage unit in an islanded DC microgrid environment. The controller is designed to ensure DC bus voltage regulation in the presence of renewable energy source and predominantly constant power loads. The performance of the proposed controller is validated through real-time simulation conducted using OPAL-RT® Digital Simulator. The controller ensures DC bus voltage regulation within tight limits and is robust with respect to wide variations in the renewable energy source power and the load.

Wear Behavior of Aluminum Alloy 6061-Based Composites Reinforced with SiC, Al 2 O 3 , and Red Mud: A Comparative Study

Abstract: Metal-matrix composites are widely used in shipping, aerospace, automotive, and nuclear applications. Research attempts have been made in the past to reduce the cost of processing of composites, decrease the weight of the composites, and increase the desired performance characteristics. In this research article, an attempt has been made in using red mud obtained as an industrial waste during the production of aluminum from bauxite ore. This article discusses the novel findings of the experimental study on the dry sliding wear behavior of aluminum alloy 6061-based composites reinforced individually with red mud, SiC, and Al2O3. The microstructural characterization of the composites provides the further insight into the structure—wear behavior of the processed composites.

New crossover operators for real coded genetic algorithm (RCGA)

Abstract: This paper aims at achieving global optimal solution of complex problems, such as traveling salesman problem (TSP), using extended version of real coded genetic algorithms (RCGA). Since genetic algorithm (GA) consists of several genetic operators, namely selection procedure, crossover, and mutation operators, that offers the choice to be modified in order to improve the performance for particular implementation, we propose three new crossover techniques for Real Coded Genetic Algorithms, which will improve the quality of solution as well as the rate of convergence to the optimum solution. Methods proposed for crossover operators are inspired by asexual reproduction commonly observed in nature. In this regard, new crossover techniques proposed incorporates the concept of Boltzmann's distribution (BD) for escaping local optima by allowing hill-climbing moves and Metropolis Algorithm (MPA), where, survival of offspring is tested before transit to new generation. Finally, these three methods are compared on various aspects like rate of convergence and quality of final solution among each other and against other randomized algorithms.