218 research outputs found
Adaptive N-Gram Classifier for Privacy Protection
We are living in a world where information is worth more than gold. Hence protecting sensitive information has become a crucial task. When telephones gave way to smartphones people not just start using them as communication tools, but to work on the go and to actively immerse in social network circles and other private communication services like chat SMS etc. Knowing each end point to the Internet is a potential risk which was a PC or laptop a while ago. Traditional methods limit the usage and somewhat the convenience of the user which dealt severely. The user knowingly or unknowingly releases sensitive information into the web which are either monitored or mined by third parties and uses them for unlawful purposes. Existing techniques mostly use data fingerprinting, exact and partial document matching and statistical methods to classify sensitive data. Keyword-based are used when the target documents are less diverse and they ignore the context of the keyword, on the other hand statistical methods ignore the content of the analyzed text. In this paper we propose a dynamic N-gram analyzer which can be used as a document classifier, we investigate the relationship of size and quality of N-grams and the effect of other feature sets like exclusion of common N-grams, grammatical words, N-gram-sizes etc. Another improvement is in the area of dynamic N-gram updater which dynamically changes the N-gram feature vectors. Our work has shown that the techniques fairly outperforms the traditional methods even when the categories exhibit frequent similarities.
DOI: 10.17762/ijritcc2321-8169.150614
Protonated chiral prolinamide catalyzed enantioselective direct aldol reaction in water
Protonated chiral prolinamide organocatalysts have been shown to catalyze an enantioselective direct aldol process in water to provide the aldol product in high yield and good enantioselectivity. The two diastereomeric catalysts (S,R)-4b and (S,S)-4c show different reactivity. © 2005 Elsevier Ltd. All rights reserved
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Stability of Microstructure in Al3003 Builds Made by Very High Power Ultrasonic Additive Manufacturing
Very High Power Ultrasonic Additive Manufacturing (VHP-UAM) system was used to
produce aluminum parts from 150 µm thick Al3003-H18 foils. The build was processed at 36 μm
vibration amplitude, 8 kN normal load, and 35.6 mm/s weld speed at 20 kHz frequency. Almost
100% linear weld density was achieved. A deformation-interaction volume of ~20 μm was
observed below the bonded interface. The microstructural stability including grain boundary
structures, and crystallographic orientations was evaluated after annealing these samples at
343oC for 2 hours and 450oC for 2 hours. After heat treatment, small grains persisted at the
interfaces with sluggish grain growth kinetics. In contrast, normal grain growth kinetics was
observed in the middle of the foils. Possible mechanisms for such phenomena are discussed.Mechanical Engineerin
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Quantitative Evaluation of Crystallographic Texture in Aluminum Alloy Builds Fabricated by Very High Power Ultrasonic Additive Manufacturing
Very high power ultrasonic additive manufacturing (VHPUAM) has shown good bond
quality over traditional ultrasonic consolidation processes. However, the stability of
microstructure in bulk and interface regions is unknown. Our earlier research showed a large
difference in grain growth kinetics between bulk and interface regions. Therefore, we have
performed in-situ studies of crystallographic texture evolution using a neutron beam line, before,
during, and after heat treatment at 343oC for 2 hours. Shear texture in the as-received condition
was found to be stronger with higher vibration amplitudes. We also observed rapid reduction of
rolling textures in the initial material and presence of shear textures even after heat treatment.Mechanical Engineerin
Power Quality Improvement Based On PSO Algorithm Incorporating UPQC
The usage of the term power quality is increasing day by day with extensive usage of large capacity loads and nonlinear loads. The major power quality issues are voltage disturbances and current disturbances in the present-day power systems. Today, with the advent of power semiconductor devices these power quality issues are solved to a great extent. The unified power quality conditioner is one such power semiconductor device which utilizes active filtering methodology to deal with the concerned power quality issues. Here an attempt is made to control and generate the reference currents and voltages for a unified power quality conditioner with the optimal tuned synchronous reference frame theory. The particle swarm optimization is employed to evolve gains of the proportional-integral controller. The unified power quality conditioner is a combination of shunt and series voltage source converters. The hysteresis band current controller for series and the pulse width modulation current controller for the shunt active filter are used for generation of gating pulses required by the switches of the voltage source converters in the unified power quality conditioner. The performance evaluation of multi-objective convergence fitness function (dealing: the voltage sag, the source current variations, and the load voltage variations) with unified power quality conditioner based on particle swarm optimization algorithm is performed. The efficacy of the proposed work is validated by conducting simulations in MATLAB/SIMULINK software environment.
Effect of boron on growth, nutrition and fertility status of large cardamom in Sikkim Himalaya, India
Field experiment was conducted at Indian Cardamom Research Institute, Regional Research Station, Spices Board Kabi research farm North Sikkim to find out the effect of Boron nutrition on growth, nutrient content and soil fertility status of large cardamom. The experiment was laid out in RBD comprising seven treatments (T1 soil application of [email protected] kg ha-1 ,T2 soil application of [email protected] kg ha-1, T3 foliar application of [email protected]%, T4 foliar application of borax @0.5%, T5 foliar application of [email protected]%+ soil application of [email protected] kg ha-1, T6 foliar application of [email protected]%+ soil application of [email protected] kg ha-1 and T7 control). Results reveal that foliar application of [email protected]%+ soil application of [email protected] kg ha-1 recorded the maximum values of immature tillers per clump (2.98 and 3.95) and mature tillers per clump (2.99 and 3.11) during both September, 2013 and March, 2014 and vegetative buds per clump (2.90 ). With regards to nutrient content in leaf of large cardamom among the treatments, foliar application of [email protected]%+soil application of [email protected] kg ha-1 recorded highest nutrient acquisition However, its effect was statistically non significant on K, S, Ca, Zn, Cu, Mn and Fe content and significant on N(2.59%), P (0.18%), Mg (0.39%) and B (15.45 ppm) content in leaf
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Bond Characterization in Very High Power Ultrasonic Additive Manufacturing
Solid parts were produced by Very High Power Ultrasonic Additive Manufacturing (VHP-UAM)
at room temperature using 150 μm thick tapes of 6061 aluminum and 110 copper alloys.
Processing was done at 20 kHz frequency over a range of parameters (26 –36 μm vibration
amplitude, 5.6 – 6.7 kN normal force, and 30.5 - 35.5 mm/s travel speed). Softening of materials
(up to about 14% in 6061 Al and 23% in 110 Cu) was noted facilitating enhanced plastic flow
and a reduction in interfacial voids. Evolution of fine recrystallized grains (0.3-4 μm in 6061 Al
and 0.3-10 μm in 110 Cu) from an initial coarser grain structure (up to 8 μm in 6061 Al and 25
μm in Cu) was observed at the build interface regions. Bonding between layers in both materials
seems to have occurred by dynamic recrystallization and movement of grain boundaries across
the interface. The energy required for the above physical processes is derived from interfacial
adiabatic plastic deformation heating.Mechanical Engineerin
multiaxial fatigue damage assessment of welded connections in railway steel bridge using critical plane approach
Abstract As the number of heavy railway traffic load increased, concern over the accurate and actual fatigue damage of the bridge is intensified. Especially for bridges which were designed for light traffic load. The fatigue damage assessment of steel bridge connections is usually based on notion of uniaxial S-N curves given in the codes of practice. Until now, there is no consensus on a method which can precisely consider non-proportional multiaxial loading. The objective of this paper is to examine the applicability and appropriateness of the critical plane approach-based C-S criterion to perform the fatigue damage assessment in welded connections in railway steel bridge. A regular U trough railway steel bridge is analyzed using finite element software ANSYS 17.2 for standard railway traffic. The averaged principal stress directions determined through appropriate weight functions are used to orient the critical plane. Prediction of fatigue damage is performed through an equivalent stress represented by a quadratic combination of the normal and the shear stress components acting on the critical plane. Applicability of the C-S criterion is studied by assessing the fatigue damage of critical welded connections and comparing with the λ - coefficient and cumulative damage method calculated according to Eurocode EN1993-1-9
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Effect of Fluid Flow on Inclusion Coarsening in Low-Alloy Steel Welds
Oxide inclusions form in welds because of deoxidation reactions in the weld pool. These inclusions control the weld microstructure development. Thermodynamic and kinetic calculation of oxidation reaction can describe inclusion characteristics such as number density, size, and composition. Experimental work has shown that fluid-flow velocity gradients in the weld pool can accelerate inclusion growth by collision and coalescence. Moreover, fluid flow in welds can transport inclusions to different temperature regions that may lead to repeated dissolution and growth of inclusions. These phenomena are being studied with the help of computational coupled heat transfer, fluid-flow, thermodynamic, and kinetic models. The results show that the inclusion formation in steel welds can be described as a function of the welding processes, process parameters, and steel composition
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