1,696 research outputs found
A Repair Framework for Scalar MDS Codes
Several works have developed vector-linear maximum-distance separable (MDS)
storage codes that min- imize the total communication cost required to repair a
single coded symbol after an erasure, referred to as repair bandwidth (BW).
Vector codes allow communicating fewer sub-symbols per node, instead of the
entire content. This allows non trivial savings in repair BW. In sharp
contrast, classic codes, like Reed- Solomon (RS), used in current storage
systems, are deemed to suffer from naive repair, i.e. downloading the entire
stored message to repair one failed node. This mainly happens because they are
scalar-linear. In this work, we present a simple framework that treats scalar
codes as vector-linear. In some cases, this allows significant savings in
repair BW. We show that vectorized scalar codes exhibit properties that
simplify the design of repair schemes. Our framework can be seen as a finite
field analogue of real interference alignment. Using our simplified framework,
we design a scheme that we call clique-repair which provably identifies the
best linear repair strategy for any scalar 2-parity MDS code, under some
conditions on the sub-field chosen for vectorization. We specify optimal repair
schemes for specific (5,3)- and (6,4)-Reed- Solomon (RS) codes. Further, we
present a repair strategy for the RS code currently deployed in the Facebook
Analytics Hadoop cluster that leads to 20% of repair BW savings over naive
repair which is the repair scheme currently used for this code.Comment: 10 Pages; accepted to IEEE JSAC -Distributed Storage 201
Mineralization changes substituted type B carbonate of PO43− ion in the bone minerals of an archaeological sample studied using fourier self deconvolution technique
277-282The aim of this study was to describe the compositional changes in the archaeological specimen using FTIR.
Fourier deconvolution was applied in the carbonate (500-650 cm−1), phosphate (900-1200 cm−1), and in the amide region (1700-1600 cm−1). The deconvolution of the spectra in the phosphate region 1200-900 cm−1 reveals six components
960 cm−1, 1010 cm−1, 1020 cm−1, 1030 cm−1, 1110 cm−1 and 1120 cm−1. The bone mineral such as CO32−, PO43− particle, collagen, and organic materials were studied in detail from the infrared spectra. The computed parameters such as collagen development, mineralization index, C/P proportion, crystalline index, and maturing of bone help us in characterizing the bone samples. The Low estimation of C/P proportion resulted in changes in Type B carbonate (PO43−) substitution. The absence of phosphate band ~1100 cm−1 and formation of β sheet structure were observed in the samples studied. Increased level of mineralization resulted in the increased in the crystalline nature of the bone samples. The study indicates the utilization of FTIR using self deconvolution technique which helps in understanding the compositional changes in the archaeological sample
A Performance Assessment on Various Data mining Tool Using Support Vector Machine
Data mining is essentially the discovery of valuable information and patterns from huge chunks of available data. Two indispensable techniques of data mining are clustering and classification, where the latter employs a set of pre-classified examples to develop a model that can classify the population of records at large, and the former divides the data into groups of similar objects. In this paper we have proposed a new method for data classification by integrating two data mining techniques, viz. clustering and classification. Then a comparative study has been carried out between the simple classification and new proposed integrated clustering-classification technique. Four popular data mining tools were used for both the techniques by using six different classifiers and one clustered for all sets. It was found that across all the tools used, the integrated clustering-classification technique was better than the simple classification technique. This result was consistent for all the six classifiers used. For both of the techniques, the best classifier was found to be SVM. From the four tools used, KNIME found to be the best in terms of flexibility of algorithm. All comparisons were drawn by comparing the percentage accuracy of each classifier used
Characterization and analysis of Gomphonema sp frustule based on SEM/EDS
1576-1579Diatoms are unicellular algae whose cell wall structure is mainly made up of silicon dioxide (SiO2). Frustules were extracted from fresh diatom taxa (Gomphonema sp.) by treating with concentrated HNO3 and HCl. The Scanning electron microscope (SEM) images revealed that the diatoms have a valve asymmetrical to apical axis and raphe system is well developed and are unequal size. From significance of energy dispersive X - ray spectroscopy (EDS) examination it was proved that the frustules from diatoms are mainly made up of silicon through amorphous silica (SiO2)
3-(7,8,13,14-Tetrahydrodibenzo[a,i]phenanthridin-5-yl)benzene-1,2-diol
In the title compound, C27H21NO2, the half-chair conformation of the alicyclic rings gives rise to a slightly folded structure of the central tricyclic tetrahydrophenanthridine unit. Tandem intramolecular O—H⋯N and O—H⋯O hydrogen bonds give rise to adjacent S(6) and S(5) rings, respectively, which dictate the conformation of the 5-aryl substituent. In the crystal structure, an intermolecular C—H⋯O contact generates chains parallel to [101]. Short O—H⋯π and C—H⋯π contacts are also observed
Defluoridation technology based on activated alumina
In this paper the experiments related to the development of defluoridation unit at domestic level for a 3 mg/1
flouride water, using activated alumina are presented in detail. The design and other specifications of the defluoridation unit are given. Details regarding the field studies in a fluorosis - affected village nearby Gandhigram are also discussed
(3E,5E)-1-Benzyl-3,5-bis(2-fluorobenzylidene)piperidin-4-one
The inversion-related molecules of the title compound, C26H21F2NO, associate into closed dimeric subunits via co-operative C—H⋯π interactions. Two non-classical C—H⋯O and one C—H⋯N intramolecular hydrogen bonds are also found in the crystal structure. The piperidin-4-one ring adopts a sofa conforamtion with the 1-benzyl group in the equatorial position, and the equiplanar fluorophenyl substituents in the 3- and 5-positions stretched out on either side. The 1-benzyl group is disposed towards the substituent in the 6th position of the piperidin-4-one ring. The 3,5-diene units possess E configurations
Influence of Nickel Coating on Flexural and Dynamic Behaviour of Aluminium
AbstractElectroless deposition is an autocatalytic chemical technique to deposit a layer of metal on a thin work piece in the presence of a reducing agent. In this work the changing structure of nickel deposits on aluminum and its alloys at the early stage of electroless nickel deposition using sodium hypophosphite ion as a reducing agent has been studied. The influences of nickel coating on flexural and dynamic behaviour of aluminium are investigated using experimental and numerical methods. Three-point bending tests are performed on coated & uncoated aluminium. The natural frequency of coated specimen and uncoated specimen has been studied. The nickel coating increases the natural frequency in aluminium. Experimental results are compared with finite element Analysis
GREEN SYNTHESIS AND CHARACTERIZATION OF SILVER NANOPARTICLES FROM WITHANIA SOMNIFERA (L.) DUNAL
The metal nanoparticle synthesis is highly explored the field of nanotechnology. The biological methods seem to be more effective because of slowreduction rate and polydispersity of the final products. The main aim of this study is too the rapid and simplistic synthesis of silver nanoparticlesby Withania somnifera Linn. at room temperature. The exposure of reaction mixtures containing silver nitrate and dried leaf powder of W. somniferaresulted in reduction of metal ions within 5 minutes. The extracellular synthesized silver nanoparticles were characterized by ultraviolet-visible,infrared (IR) spectroscopy, X-ray diffraction studies, zeta potential, Fourier transform IR, and scanning electron microscopy. The antibacterial andantifungal studies showed significant activity as compared to their respective standards. From the results, W. somnifera sliver nanoparticle has attainedthe maximum antimicrobial against clinical pathogens and also seen very good stability of nanoparticle throughput processing. As we concluded, thistype of naturally synthesized sliver nanoparticle could be a better green revolution in medicinal chemistry.Keywords: Antimicrobial activity, Silver nanoparticles, Withania somnifera
(3E,5E)-3,5-Bis(4-allyloxybenzylidene)-1-benzylpiperidin-4-one
In the title compound C32H31NO3, the allyloxy groups on either side of the piperidin-4-one ring are conformationally disordered. The contribution of major and minor components of the allyloxy group at the 3rd position of the ring are 0.576 (4) and 0.424 (4), respectively, and those at the 5th position are 0.885 (3) and 0.115 (3), respectively. The six-membered piperidin-4-one ring adopts a sofa conformation with the benzyl group occupying an equatorial position and the olefinic double bonds possessing an E configuration. Flanking phenyl substituents are stretched out on either side of the six-membered ring. π–π interactions with a centroid–centroid distance of 3.885 (1) Å give rise to molecular dimers and short C—H⋯π contacts lead to chains along the c axis
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