Investigating the performance of Hadoop and Spark platforms on machine learning algorithms

One of the most challenging issues in the big data research area is the inability to process a large volume of information in a reasonable time. Hadoop and Spark are two frameworks for distributed data processing. Hadoop is a very popular and general platform for big data processing. Because of the in-memory programming model, Spark as an open-source framework is suitable for processing iterative algorithms. In this paper, Hadoop and Spark frameworks, the big data processing platforms, are evaluated and compared in terms of runtime, memory and network usage, and central processor efficiency. Hence, the K-nearest neighbor (KNN) algorithm is implemented on datasets with different sizes within both Hadoop and Spark frameworks. The results show that the runtime of the KNN algorithm implemented on Spark is 4 to 4.5 times faster than Hadoop. Evaluations show that Hadoop uses more sources, including central processor and network. It is concluded that the CPU in Spark is more effective than Hadoop. On the other hand, the memory usage in Hadoop is less than Spark.

     

Facile Synthesis,Characterization, Catalytic and Photocatalytic Activity of Multiferroic BiFeO3 Perovskite Nanoparticles

We report the synthesis of multiferroic BiFeO₃ perovskite nanoparticles using the microwave combustion technique. Phase evolution is investigated by XRD, which confirms that the formation of a secondary α-Bi₂O₃ phase with a monoclinic structure along with the existing rhombohedral (BiFeO₃) structure. The average crystalline size has been found at 50 nm. The optical band gap was calculated from the Tauc’s plot it has been found 2.18 eV. The appearances of FT-IR spectra revealed bands at 550 and 444 cm^?1 were correlated to the rhombohedral stretching modes of BiFeO₃ nanostructure. The surface morphology showed the formation of nanosized grains with pores. The magnetization-Field (M-H) hysteresis curves revealed the appearance of ferrimagnetic behavior at room temperature. The BET surface area of BiFeO₃ perovskite nanoparticles was found 44.86 m²/g. The as-fabricated BiFeO₃ perovskite nanoparticles were investigated for their superior catalytic activity in two applications, which include (i) Glycerol to formic acid oxidation in the liquid phase with a high efficiency of over 98 percent, (ii) Under visible light, the photocatalytic breakdown of rhodamine B achieved maximal efficiency (almost 99 percent). Finally, we concluded that the BiFeO₃ perovskite nanoparticles exhibit high performance in future multifunctional devices is demonstrated by the simultaneous enhancement of catalytic and photocatalytic activities.