Distributed and incremental travelling salesman algorithm on time-evolving graphs

The Journal of Supercomputing - Travelling salesman problem (TSP) is a graph problem that has been widely used in many applications, especially for transportation and logistics. Because TSP is a NP...     

A new approach for generating efficient sample from market basket data

Classical data mining algorithms require expensive passes over the entire database to generate frequent items and hence to generate association rules. With the increase in the size of database, it is becoming very difficult to handle large amount of data for computation. One of the solutions to this problem is to generate sample from the database that acts as representative of the entire database for finding association rules in such a way that the distance of the sample from the complete database is minimal. Choosing correct sample that could represent data is not an easy task. Many algorithms have been proposed in the past. Some of them are computationally fast while others give better accuracy. In this paper, we present an algorithm for generating a sample from the database that can replace the entire database for generating association rules and is aimed at keeping a balance between accuracy and speed. The algorithm that is proposed takes into account the average number of small, medium and large 1-itemset in the database and average weight of the transactions to define threshold condition for the transactions. Set of transactions that satisfy the threshold condition is chosen as the representative for the entire database. The effectiveness of the proposed algorithm has been tested over several runs of database generated by IBM synthetic data generator. A vivid comparative performance evaluation of the proposed technique with the existing sampling techniques for comparing the accuracy and speed has also been carried out.     

Optimized ensemble decision-based multi-focus imagefusion using binary genetic Grey-Wolf optimizer in camera sensor networks

Modern developments in image technology enabled easy access to an innovative type of sensor-based networks, Camera or Visual Sensor Networks (VSN). Nevertheless, more sensor data sources bring about the problem of overload information. To solve this problem, some researchers have been carried out on the techniques to counteract the data overload caused by sensors without losing useful data. The aim of fusion in each application is to combine images from several sensors, which leads to the decreased amount of input image data, producing an image with more accurate data. This paper proposes a noisy feature removal scheme for multi-focus image fusion combining the decision information of optimized individual features. The proposed scheme is developed in two main steps. In the first step, the diverse types of features are extracted from each block of input blurred images. The useful information of these individual features indicates which image block is more focused among corresponding blocks in source images. After that, noisy features are removed using binary Genetic Grey wolf optimizer (GGWO) algorithm. The ensemble decision based on individual features is employed to fuse blurred images in the second step. The experimentation is evaluated on different multi-focus images and it reveals that GGWO based proposed method performs better visual quality than other methods.     

CVD synthesis of graphene nanoplates on MgO support

Synthesis of graphene directly on MgO has been carried out and the structural properties of the obtained material have been investigated. Few-layered graphene was produced by simple thermal decomposition of methane over MgO powder at 950 °C in a CVD reactor. The samples were purified by 10 N HNO₃ treatment, and studied by TEM, Raman spectroscopy, EDAX and SEM. TEM clearly indicated the formation of graphene. EDAX showed that the purified sample contained only carbon and no traces of MgO. The characteristic Raman features of graphene were also seen as D-band at 1316 cm^?1, G-band at 1602 cm^?1, and a small 2D-band at 2700 cm^?1 in the Raman spectra. The strong D-band suggests that the graphene possess large number of boundary defects. The small 2D-band indicates the formation of few-layered graphene.     

Flat Absorber Phosphorous Black Nickel Coatings for Space Applications

A new process of flat absorber black nickel alloy coating was developed on stainless steel by electrodeposition from a bath containing nickel,zinc and ammonium sulphates;thiocyanate and sodium hypophosphite for space applications.Coating process was optimized by investigating the effects of plating parameters,viz concentration of bath constituents,current density,temperature,pH and plating time on the optical properties of the black deposits.Energy dispersive X-ray spectroscopy showed the inclusion of about 6% phosphorous in the coating.The scanning electron microscopy studies revealed the amorphous nature of the coating.The corrosion resistance of the coatings was evaluated by the electrochemical impedance spectroscopy (EIS) and linear polarization (LP) techniques.The results revealed that,phosphorous addition confers better corrosion resistance in comparison to conventional black nickel coatings.The black nickel coating obtained from hypophosphite bath provides high solar absorptance (α s) and infrared emittance (ε IR) of the order of 0.93.Environmental stability to space applications was established by the humidity and thermal cycling tests.     

Viscoelastic properties of borax loaded CMC‐g‐cl‐poly(AAm) hydrogel composites and their boron nutrient release behavior

Borax (Na₂B₄O₇, 10.5% Boron) loaded CMC‐g‐cl‐poly(AAm) hydrogel composites were prepared by in situ grafting of acrylamide on to sodium carboxymethyl cellulose in the presence of borax by free radical polymerization technique to develop slow boron (B) delivery device. The composition, morphology, and mechanical properties of synthesized composites were studied by X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, texture analyser, and dynamic shear rheometer. Characterization revealed formation of borate ion ( ) from borax during polymerization reaction leading to extensive crosslinking of cellulosic chains and generation of mechanically strong composite hydrogels. Dynamic release of from the synthesized composites hydrogels followed Fickian diffusion mechanism and composites with high mechanical strength resulted in slow release of B. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43969.     

Structural and Dielectric Properties of Ca Doped Barium Iron Niobate

Ceramic materials with high dielectric constant are being used in many electric and electro-optics applications. Ca substituted barium iron niobate with general formula (Ba_1-xCa_x) (Fe_0.5Nb_0.5)O₃ with x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 were prepared by conventional solid state reaction method. Structural properties were investigated using X-ray diffraction and scanning electron microscope. Two types of phases were observed for 0.4 ≤ x ≤ 08. Dielectric constant and loss tangent were measured using impedance analyzer in the frequency range of 20 Hz–1 MHz at room temperature. Dielectric constant and loss tangent were found to decrease with increasing the frequency. A relatively good combination of dielectric constant and loss tangent was obtained for x = 0.2 (?_r = 1441 and tan δ = 0.19) at 10 KHz.