601 research outputs found
Non-Negative Matrix Factorization Based Single Channel Source Separation
The significance of speech recognition systems is widespread, encompassing applications like speech translation, robotics, and security. However, these systems often encounter challenges arising from noise and source mixing during signal acquisition, leading to performance degradation. Addressing this, cutting-edge solutions must effectively incorporate temporal dependencies spanning longer periods than a single time frame. To tackle this issue, this study introduces a novel model employing non-negative matrix factorization (NMF) modelling. This technique harnesses the scattering transform, involving wavelet filters and pyramid scattering, to compute sources and mitigate undesired signals. Once signal estimation is achieved, a source separation algorithm is devised, employing an optimization process grounded in training and testing approaches. By quantifying performance metrics, a comparative analysis is conducted between existing methods and the proposed model. Results indicate the superior performance of the suggested approach, underscored by these metrics. This signifies that the NMF and scattering transform-based model adeptly addresses the challenge of effectively utilizing temporal dependencies spanning more than a single time frame, ultimately enhancing speech recognition system efficacy
Enhancing the Performance of Single-Channel Blind Source Separation by Using ConvTransFormer
In the specialized field of audio signal processing, this study introduces a pioneering ConvTransFormer architecture aimed at enhancing the performance of single-channel blind source separation (SCBSS). This innovative architecture ingeniously combines the strengths of a multiple simple-weak attention mechanism with the triple-gating feature of a Gated Attention Unit (GAU) within the ConvTransFormer. This combination allows for a more focused and effective targeting of specific segments within the input sequence. The efficacy of this ConvTransFormer architecture is rigorously evaluated using the WSJ0-2mix dataset, a standard benchmark in the field. The results of this evaluation are significant, demonstrating substantial improvements in key performance metrics. Notably, there is an increase in the Signal-to-Interference (SI)-Signal-to-Noise Ratio improvement (SNRi) by 16.5 and in the Signal-to-Distortion Ratio improvement (SDRi)-Signal-to-Interference (SDRi) by 16.8. These improvements are crucial indicators of the quality of source separation in SCBSS. The findings of this research are groundbreaking, indicating that the proposed ConvTransFormer architecture surpasses existing methods in both SI-SNRi and SDRi performance metrics. This advancement marks a significant step forward in the field of SCBSS, offering new avenues for more effective and precise audio signal processing, especially in scenarios where isolating individual sound sources from a single- channel input is essential
A Survey: Massive MIMO for next Generation Cellular Wireless Technologies
The rapid development of MIMO technology in the area of wireless communications is to setting up of base stations with large number of antennas to improvements in energy and spectral efficiency. In this paper a detailed survey on massive technology, its advantages and comparison with existing method are proposed. The Long Term Evolution (LTE) has been designed to support only packet-switched services and is aimed to provide IP connectivity between UE and eNodeB. As we move forward to5G becoming more promising next generation technology with increase in capacity, reduced latencies, support of very high frequencies (mmWave) with a smaller size single antenna, smaller the aperture for receiving energy. To overcome this small aperture on receiver side at high frequency, we need to use a large number of transmission antenna. This would be the main reason to use the Massive Multiple Input Multiple Outputs (MIMO).This paper focused on the massive MIMO performance, the gain, and return losses of different antennas operating at different frequencies
A dynamical approach to the spatiotemporal aspects of the Portevin-Le Chatelier effect: Chaos,turbulence and band propagation
Experimental time series obtained from single and poly-crystals subjected to
a constant strain rate tests report an intriguing dynamical crossover from a
low dimensional chaotic state at medium strain rates to an infinite dimensional
power law state of stress drops at high strain rates. We present results of an
extensive study of all aspects of the PLC effect within the context a model
that reproduces this crossover. A study of the distribution of the Lyapunov
exponents as a function of strain rate shows that it changes from a small set
of positive exponents in the chaotic regime to a dense set of null exponents in
the scaling regime. As the latter feature is similar to the GOY shell model for
turbulence, we compare our results with the GOY model. Interestingly, the null
exponents in our model themselves obey a power law. The configuration of
dislocations is visualized through the slow manifold analysis. This shows that
while a large proportion of dislocations are in the pinned state in the chaotic
regime, most of them are at the threshold of unpinning in the scaling regime.
The model qualitatively reproduces the different types of deformation bands
seen in experiments. At high strain rates where propagating bands are seen, the
model equations are reduced to the Fisher-Kolmogorov equation for propagative
fronts. This shows that the velocity of the bands varies linearly with the
strain rate and inversely with the dislocation density, consistent with the
known experimental results. Thus, this simple dynamical model captures the
complex spatio-temporal features of the PLC effect.Comment: 17 pages, 18 figure
Fast Subpixel Full Search Motion Estimation
Motion estimation is one of the most important part in video coding, where only the difference between the current and reference frames will be coded by the encoder.There are many advancements happening in motion estimation techniques. The proposed algorithm provides high precision matching and even reduces the errors during compensation. The algorithm also reduces the computation time when compared to traditional Block matching techniques. It mainly aims at the motion estimation with subpixelaccuracy without interpolation, it is the combination of Block matching and the optical flow method.Fast computation may be evaluated by experimental results while even motion vectors are more accurate reducing the PSNR
USE OF WATER QUALITY INDEX TO DETERMINE SUITABILITY AND EASONAL DISSIMILARITY OF WATER BODIES IN HASSAN, KARNATAKA, INDIA
ABSTRACT To assess spatial and sequential contamination of selected water bodies using Water Quality Index (WQI) has been calculated for Channarayapatna (SC 1 and SC 2 ), Bagur (SB 1 and SB 2 ), Janivara (SJ 1 and SJ 2 ) and Anekere (SA 1 and SA 2 ) at Channarayapatna taluk during pre-monsoon season and monsoon season. Water quality parameters were selected as per the WHO guidelines. Fourteen water quality physico-chemical parameters were estimated as per the standard methods and procedures. Drinking water at almost all the sites was found to be highly contaminated, except a few sites, where it was found moderately contaminated for both the seasons during the year 2011. In general, to some extent water quality showed deterioration after the onset of monsoon. The rural village activity produces a serious and negative effect on the water quality, this is due sewage discharge from the villages. Water Quality Index (WQI) was also calculated to know the overall quality of water samples. The results show that the water quality index is observed in the range of 75-98 and expected in the range of 75-98 which shows marginally water quality for drinking purposes. The water quality index is calculated by indicator (100-point scale) shows that this water can be used for drinking purpose after purification treatment. Results show that quality for irrigation purpose is quite good. It was found that some effective measures are urgently required for water quality management in this region
Multi-input Fuzzy Logic Controller for Brushless dc Motor Drives
The brushless dc motors are used in various applications such as defence, industries,robotics, etc. In these applications, the motor should be precisely controlled to give the desiredperformance. The proposed controller systems consist of multi-input fuzzy (two-and three-input)logic controller (FLC) and multi-input integrated fuzzy logic controller (IFLC) for the speed controlof brushless dc servomotor drive. The input for the controllers are error e(k), change in error[first derivative of error ce(k)] and change of change in error [second derivative of error cce(k)]with a single-output. The error cce(k) is substantial at the overshoots/undershoots and is thereforeessential for accurate speed control of brushless dc motor. The error cce(k) has been introducedfor the first time in the literature as one of the input in the FLC and IFLC design. The IFLC isdesigned using FLC and proportional derivation integral (PID) controllers. The controller systemshave been studied systematically for the transient and steady-state conditions. The three-inputIFLC is found to be superior, more robust, faster, flexible, and is insensitive to the parametervariations as compared with the FLC (with two-and three-input) and conventional two-inputIFL
The Acute Inflammatory Biomarkers - Are They Cost Effective and Real Time Early Predictors of Mortality in Acute Pneumonia? - A Prospective Observational Study
Introduction: The CT chest and investigations like IL6 and TNFÉ‘ are the most accurate blood biomarkers of inflammatory changes and can be used to stage the severity and outcome of acute pneumonia. . Getting all the above mentioned investigations in a financially poor patients is not always possible. There are not much studies to look for the association between early raise in serum acute inflammatory bio markers and the prediction of mortality in acute pneumonia. So this study is under taken to know the association between significant raise in serum acute inflammatory biomarkers like hs CRP, LDH, ferritin, NLR, WBCs count in predicting the mortality of acute pneumonia in comparison with the serum IL6,q-SOFA score and CT chest severity score. Materials & Method: All patients underwent standardized workup, including complete blood count, blood biochemistry, ferritin, hs-CRP, LDH,IL6,CT scan of chest ,q-SOFA score assessment and electrocardiogram. All the biochemical investigations were done on day 1 and day 5 of admission to the hospital. The patients were followed-up for the whole in hospital stay duration. Results: All the measured serum acute inflammatory bio markers, IL6, NLR, WBCs count, q-SOFA score and chest CT severity score were significantly elevated in patients with death due to acute pneumonia than the survived ones. [p value-0.01] Conclusion: This study proves that, the early raise in serum acute inflammatory biomarkers have got real and cost effective predictive value and are non-inferior to total WBCs count, NLR,IL6, q- SOFA score and chest CT severity score in assessing the mortality of acute pneumonia. Keywords: Acute Pneumonia, Acute inflammatory bio markers, CT scan of Chest, IL6, NLR (Neutrophils to Lymphocytes ratio), q-SOFA score, WBCs coun
Synthesis and Stoichiometry of MgB2
The system MgxB2 has been investigated to investigate possible
nonstoichiometry in MgB2. When synthesized at 850oC, MgB2 is a line compound
with a possible Mg vacancy content of about 1%. Small changes in lattice
constants as a function of starting composition result from grain interaction
stresses, whose character is different in the Mg-rich, near-stoichiometric, and
Mg-deficient regimes. A small linear decrease of the superconducting transition
temperature, Tc, in the Mg-rich regime results from accidental impurity doping.Comment: Accepted for publication in Physica C. 24 pages, 7 figure
Effect of PVA doping on flux pinning in Bulk MgB2
The synthesis and characterization of PVA (Poly Vinyl Acetate) doped bulk
MgB2 superconductor is reported here. PVA is used as a Carbon source. PVA
doping effects made two distinguishable contributions: first enhancement of Jc
field performance and second an increase in Hc2 value, both because of carbon
incorporation into MgB2 crystal lattice. The susceptibility measurement reveals
that Tc decreased from 37 to 36 K. Lattice parameter a decreased from 3.085 A
to 3.081 A due to the partial substitution of Carbon at Boron site. PVA doped
sample exhibited the Jc values greater than 10^5 A/cm2 at 5 & 10 K at low
fields; which is almost 3 times higher than the pure one, while at high fields
the Jc is increased by an order of magnitude in comparison to pure MgB2. From
R(T)H measurements we found higher Tc values under magnetic field for doped
sample; indicating an increase in Hc2. Also the magnetization measurements
exhibited a significant enhancement in Hirr value. The improved performance of
PVA doped MgB2 can be attributed to the substitution of carbon at boron site in
parent MgB2 and the resulting impact on the carrier density and impurity
scattering. The improved flux pinning behavior could easily be seen from
reduced flux pinning force plots.Comment: 14 Pages of Text + Figs. To appear in Physica
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