447 research outputs found
Exact Solution of the Zakharov-Shabat Scattering Problem for Doubly-Truncated Multi-Soliton Potentials
Recent studies have revealed that multi-soliton solutions of the nonlinear
Schr\"odinger equation, as carriers of information, offer a promising solution
to the problem of nonlinear signal distortions in fiber optic channels. In any
nonlinear Fourier transform based transmission methodology seeking to modulate
the discrete spectrum of the multi-solitons, choice of an appropriate windowing
function is an important design issue on account of the unbounded support of
such signals. Here, we consider the rectangle function as the windowing
function for the multi-solitonic signal and provide the exact solution of the
associated Zakharov-Shabat scattering problem for the windowed/doubly-truncated
multi-soliton potential. This method further allows us to avoid prohibitive
numerical computations normally required in order to accurately quantify the
effect of time-domain windowing on the nonlinear Fourier spectrum of the
multi-solitonic signals. The method devised in this work also applies to
general type of signals and may prove to be a useful tool in the theoretical
analysis of such systems.Comment: The manuscript is revised for submission to PRE. Also, some typos
have been correcte
Carbon Dioxide Appropriation Using Alkanolamine Blends: Vapor-Liquid Equilibrium Modelling Approach
Design of sour-gas treating processes with alkanolamine solvents requires knowledge of vapor liquid equilibrium(VLE)of the aqueous acid gas–alkanolamine systems.An approximate thermodynamic model is developed to correlate and predict the vapor-liquid equilibrium(VLE)of CO2 in aqueous N-Ethyl Ethanolamine (EAE) solution in the temperature range (303.1-323.1 K).The values of deprotonation constant(K4)and carbamate reversion constant(K5)are determined by using the model derived from the VLE data of the ternary system(CO2 + EAE+ H2O).The model predictions are in good agreement with the experimental data of CO2 solubility in aqueous EAE solution available in the open literature.Similarly modified Kent Eisenberg model is validated for the quaternary(CO2 + AMP+PZ+ H2O)system.To consider the phase non-ideality in the(CO2+AMP+PZ+H2O)system we assumed the equilibrium constants are a function of temperature,CO2 partial pressure and amine concentration.The adjustable equilibrium constants Ki’ are then estimated.Rigorous thermodynamic model i.e.NRTL model is developed and VLE data of(CO2 + MDEA+ H2O)is correlated to find out the interaction parameters.The model predictions are in good agreement with the experimental data of CO2 solubility in aqueous MDEA solution available in the open literature.Density and viscosity of two novel tertiary alkanolamines including1-(2-hydroxyethyl)piperidine(1-(2-HE)PP)and 2-diethylaminoethanol(DEAE)in their aqueous blends with Piperazine(PZ)have been measured over a temperature range of(303.1, 308.1, 313.1, 318.1, 323.1)K and total amine mass fraction in all the blends was kept constant at 30 %.The mass % ratios of(PZ)/ (1-(2-HE)PP or DEAE)considered for measurements were 3/27, 6/24, 9/21 and 12/18.Density and viscosity of the ternary mixtures were correlated as functions of temperature and amine composition using thermodynamic framework.Modeling and simulation is done in MATLAB platform
Observation of Mixed Alkali Like Behaviour by Fluorine Ion in Mixed Alkali Oxyfluro Vanadate Glasses: Analysis from Conductivity Measurements
In this communication we report the fluorine ion dynamics in mixed alkali
oxyfluro vanadate glasses. We have measured the electrical conductivity using
impedance spectroscopy technique Room temperature conductivity falls to 5
orders of magnitude from its single alkali values at 33 mol% of rubidium
concentration. We have also estimated the distance between similar mobile ions
using the density values. Assuming this distance as the hopping distance
between the similar ions we have estimated the anionic (Fluorine ion in our
case) conductivity. It is observed that the fluorine ion dynamics mimics the
mixed alkali effect and scales as the onset frequency f0.Comment: submitted to DAE-SSDP 2018 Indi
SourcererCC: Scaling Code Clone Detection to Big Code
Despite a decade of active research, there is a marked lack in clone
detectors that scale to very large repositories of source code, in particular
for detecting near-miss clones where significant editing activities may take
place in the cloned code. We present SourcererCC, a token-based clone detector
that targets three clone types, and exploits an index to achieve scalability to
large inter-project repositories using a standard workstation. SourcererCC uses
an optimized inverted-index to quickly query the potential clones of a given
code block. Filtering heuristics based on token ordering are used to
significantly reduce the size of the index, the number of code-block
comparisons needed to detect the clones, as well as the number of required
token-comparisons needed to judge a potential clone.
We evaluate the scalability, execution time, recall and precision of
SourcererCC, and compare it to four publicly available and state-of-the-art
tools. To measure recall, we use two recent benchmarks, (1) a large benchmark
of real clones, BigCloneBench, and (2) a Mutation/Injection-based framework of
thousands of fine-grained artificial clones. We find SourcererCC has both high
recall and precision, and is able to scale to a large inter-project repository
(250MLOC) using a standard workstation.Comment: Accepted for publication at ICSE'16 (preprint, unrevised
Reductive Biotransformation of Ethyl Acetoacetate: A Comparative Studies using Free and Immobilized Whole Yeast Cells
Bioreduction of ethyl acetoacetate with free and immobilized yeast whole cell was achieved by using water and sucrose combination. After detachment from immobilized beads under basic condition, the corresponding ethyl(S)-(+)-3-hydroxybutanoate was isolated with 98 to 100% yield. Immobilized beads of yeast whole cell were prepared at different temperature which affects the morphology and physiology of the beads for the diffusion of the enzyme, which shown the maximum conversion of the substrate to products as compared to the free yeast whole cell
Early recovery after surgery in elective obstetrics-gynaecology surgeries: prospective single-center pilot study
Background: Enhanced recovery after surgery (ERAS) programmes employed in elective colorectal, vascular, urologic and orthopaedic surgery has provided strong evidence for decreased hospital stay without increase in postoperative complications. The aim of the study was to explore role and benefits, if any, of ERAS/ERP (early recovery protocols) implemented in patients undergoing elective obstetrics-gynaecological surgeries.Methods: Prospective cohort of 48 consecutive patients undergoing elective obstetrics-gynaecological surgeries were included. ERP included early feeding, urinary catheter removal, mobilisation/physiotherapy, intravenous line removal and optimal oral analgesia. This was compared to control group of 50 patients undergoing similar operations prior to introduction of ERP, SPC group-standard perioperative care. Demographics and indications of surgeries were similar for both groups. The primary end-points were length of stay (LOS) and incidence of complications (Clavien-Dindo classification). Difference in means was tested using the t test assuming unequal variances. Statistical significance was defined as p<0.05.Results: Two groups, A (non-ERAS/SPC) and B (ERAS) were comparable with regards to demographics and indication of surgery. The mean time to solid diet, urinary catheter removal, mobilization, iv fluid removal and shift to oral analgesia was 2.57, 1.13 (p<0.00001), 1.99 ,1.03 (p<0.00268), 1.63, 1.2 (p<0.00001), 1.72, 1.14 (p<0.00001), 1.8, 1.37 (p<0.00001) days respectively. There were 31 and 21 complications in both groups, respectively (p<0.0097). Hospital stay was significantly shorter in the ERAS group, 2.87, 2.61 (p<0.0378).Conclusions: This pilot study shows that ERPs can be successfully implemented with significant shorter hospital stays without increase in postoperative complications in elective obstetrics-gynecology patients
Gas–liquid flow in stirred reactors: Trailing vortices and gas accumulation behind impeller blades
In a gas–liquid stirred reactor, gas tends to accumulate in low-pressure regions behind the impeller blades. Such gas accumulation significantly alters impeller performance characteristics. We have computationally investigated gas–liquid flow generated by a Rushton (disc) turbine. Rotating Rushton turbine generates trailing vortices behind the blades, which influence the gas accumulation in the impeller region. Characteristics of these trailing vortices were first investigated by considering a model problem of flow over a single impeller blade. Predicted results were compared with the published experimental data. Circulation velocity and turbulent kinetic energy of the trailing vortices were found to scale with blade tip velocity. Several numerical experiments were carried out to understand interaction of gas bubbles and trailing vortices. Gas–liquid flow in stirred vessel was then simulated by extending the computational snapshot approach of Ranade and Dometti (Chem. Engng Res. Des., 74, 476–484, 1996). The approach was able to capture the main features of gas–liquid flow in stirred vessels. The detailed analysis of predicted results with reference to experimental data and the results obtained for flow over a single impeller blade will be useful for extending the scope of computational fluid dynamics (CFD) based tools for engineering gas–liquid stirred reactors
Semi-Supervised Imitation Learning of Team Policies from Suboptimal Demonstrations
We present Bayesian Team Imitation Learner (BTIL), an imitation learning
algorithm to model the behavior of teams performing sequential tasks in
Markovian domains. In contrast to existing multi-agent imitation learning
techniques, BTIL explicitly models and infers the time-varying mental states of
team members, thereby enabling learning of decentralized team policies from
demonstrations of suboptimal teamwork. Further, to allow for sample- and
label-efficient policy learning from small datasets, BTIL employs a Bayesian
perspective and is capable of learning from semi-supervised demonstrations. We
demonstrate and benchmark the performance of BTIL on synthetic multi-agent
tasks as well as a novel dataset of human-agent teamwork. Our experiments show
that BTIL can successfully learn team policies from demonstrations despite the
influence of team members' (time-varying and potentially misaligned) mental
states on their behavior.Comment: Extended version of an identically-titled paper accepted at IJCAI
202
Selection of Gate Dielectrics for ZnO Based Thin-Film Transistors
The bulk of semiconductor technology has been based on silicon till today. But silicon has its own limitations. It is not transparent to visible light and hence it cannot be used in certain applications. ZnO is a material which is transparent to visible light. In this paper, we compare the electrical performance of ZnO Thin film Transistors using different gate insulators. Certain performance indices and material indices were considered as the selection criteria for electrical performance. A methodology known as Ashby\u27s approach was adopted to find out the best gate insulators and based on this methodology various charts were plotted to compare different properties of competing materials. This work concludes that Y2O3 is the best insulator followed by ZrO2 and HfO2
Inclined Slots on Broad wall of Ridged Waveguide
A new inclined slot array on the broad wall of a single ridged rectangular waveguide is proposed. This paper presents slot array with similar inclination for all slots, slot array with different inclination and non-uniform length slots with different inclination on broad wall of a single ridged rectangular waveguide for vertical polarization. The co and cross polarization curves of the three designs are compared at different angles of observation
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