Vignan University

About: Vignan University is a education organization based out in Guntur, Andhra Pradesh, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 1138 authors who have published 1381 publications receiving 7798 citations.

Sparse NMF based speech enhancement with bases update

Abstract: In this paper, a combination of methods based on statistical modelling and Non-negative Matrix Factorization (NMF) for speech enhancement using speech and noise bases with on-line update is proposed. Template-based approaches are known to be more robust in the presence of non-stationary noises than methods based on statistical modeling. However, template-based approaches depend on a-priori information. The drawbacks of both the approaches can be avoided by combining them. In NMF approach, speech bases and noise bases are simultaneously adapted to further improve the performance. The proposed method outperforms other benchmark algorithms in terms of perceptual evaluation of speech quality (PESQ) and source-to-distortion ratio (SDR) in stationary and non-stationary noise environment conditions with matched and mismatched noise basis.

Chemical Stability and Spectroscopic Characterization of Balofloxacin and its Stress Degradation Products by LC-PDA, LC-MS/MS, NMR and FT-IR

Abstract: The present manuscript describes the preparative isolation and characterization of three degradation products of Balofloxacin (BFX). The drug is subjected to different stress conditions under acidi...

Location controlled symmetry reduction: paradigm of an open metalloporphyrin framework based on the tetracarboxy porphyrin linker

Abstract: Location controlled symmetry reduction of the tetracarboxy porphyrin linker by altering the position of the coordinating groups leads to the design of a novel reduced symmetry linker 5,15-bis(p-carboxyphenyl)-10,20-bis(m-carboxyphenyl)porphyrin (H4-TpmCPP). The corresponding crystalline coordination framework Gd-TpmCMPF was synthesized by employing the NaOH modulator approach. The resulting compound is an 8-connected network with a bcu topology and two different perforated 1D channels. The consequence of reduced symmetry is highlighted in the geometry of capsular void spaces formed between porphyrin moieties in the framework which allows coordination with formate ions in the reaction mixture.

Nonlinear system parameter estimation of drying process using modified state transition algorithm in cloud environment

Abstract: The parameter estimation optimisation with constraints for the nonlinear complex system requires a serious of computation. This paper introduced a novel constrained optimisation method named Lagrangian-based state transition algorithm (LSTA) to solve problems in distributed cloud computing environment. LSTA with the physical constraints involved in solving the problems which occurs while the conventional techniques are used. In LSTA, the updating of the result to an optimisation problem with constraints known as, a state transition. The Lagrangian multiplier is used as a constraint for state transition process to estimate the drying process system effectively. The experiments are conducted in the cloud computing environment and simulated results validated the proposed LSTA methodology for parameter estimation. This method is a promising way for system identification due to its searching competency, enduring performance considering physical limitations and quick convergence.