Stabilizing Stochastic Predictive Control under Bernoulli Dropouts

This article presents tractable and recursively feasible optimization-based controllers for stochastic linear systems with bounded controls. The stochastic noise in the plant is assumed to be additive, zero mean and fourth moment bounded, and the control values transmitted over an erasure channel. Three different transmission protocols are proposed having different requirements on the storage and computational facilities available at the actuator. We optimize a suitable stochastic cost function accounting for the effects of both the stochastic noise and the packet dropouts over affine saturated disturbance feedback policies. The proposed controllers ensure mean square boundedness of the states in closed-loop for all positive values of control bounds and any non-zero probability of successful transmission over a noisy control channel

Output feedback stable stochastic predictive control with hard control constraints

We present a stochastic predictive controller for discrete time linear time invariant systems under incomplete state information. Our approach is based on a suitable choice of control policies, stability constraints, and employment of a Kalman filter to estimate the states of the system from incomplete and corrupt observations. We demonstrate that this approach yields a computationally tractable problem that should be solved online periodically, and that the resulting closed loop system is mean-square bounded for any positive bound on the control actions. Our results allow one to tackle the largest class of linear time invariant systems known to be amenable to stochastic stabilization under bounded control actions via output feedback stochastic predictive control

Measurements of Three Dimensional Temperature Field in Fluids using Laser Interferometry

Non-intrusive measurement of fluid temperature using laser interferometry is reported. As a case study, results obtained in Rayleigh-Benard convection experiment are presented. Image processing operations required for the evaluation interferograms and extraction of quantitative data from the optical Images are discussed. Limited-view tomographic algorithms applicable to interferometry are discussed and compared in terms of reconstructed three-dimensional temperature fields. This study concludes that laser interferometry coupled with tomography promises a versatile tool for three-dimensional temperature and flow field measurements in fluids

Quasi-Degenerate Neutrinos in Type II Seesaw Models

We present an analysis of normal and inverted hierarchical neutrino mass models within the framework of tri-bi-maximal (TBM) mixing. Considering the neutrinos to be quasi-degenerate (QDN), we study two different neutrino mass models with mass eigenvalues $(m_1, -m_2, m_3)$ and $(m_1, m_2, m_3)$ for both normal hierarchical (NH) and inverted hierarchical (IH) cases. Parameterizing the neutrino mass matrix using best fit oscillation and cosmology data for a QDN scenario, we find the right-handed Majorana mass matrix using type I seesaw formula for two types of Dirac neutrino mass matrices: charged lepton (CL) type and up quark (UQ) type. Incorporating the presence of type II seesaw term which arises naturally in generic left-right symmetric models (LRSM) along with type I term, we compare the predictions for neutrino mass parameters with the experimental values. Within such a framework and incorporating both oscillation as well as cosmology data, we show that QDN scenario of neutrino masses can still survive in nature with some minor exceptions. A viable extension of the standard model with an abelian gauged flavor symmetry is briefly discussed which can give rise to the desired structure of the Dirac and Majorana mass matrices.Comment: Version 2: Typos corrected, texts+tables rearranged, conclusion unchanged. Accepted for publication in Physical Review

PLGA Microspheres Incorporated Gelatin Scaffold: Microspheres Modulate Scaffold Properties

Freeze drying is one of the popular methods of fabrication for poly(lactide-co-glycolide) (PLGA) microspheres incorporated polymer scaffolds. However, the consequence of microspheres incorporation on physical and biological properties of scaffold has not been studied yet. In this study, attempt has been made to characterize the effect of PLGA microsphere incorporation on the physical properties of freeze-dried gelatin scaffold and its influence on cytocompatibility. Scaffolds loaded with varying amount of PLGA microspheres (10%, 1%, 0.1% w/w) were subjected to microarchitecture analysis, swelling, porosity, mechanical properties, biodegradation, cell adhesion, and cell proliferation studies. Results revealed that an increase in percentage loading of microspheres reduced the pore size and uniformity of the pore structure. Moreover, loading of PLGA microspheres up to 1% w/w significantly increased porosity, swelling, and mechanical properties of the scaffold but variations were not proportional for 10% w/w loading. Results also showed that PLGA microspheres have no significant effect on cell adhesion but influenced the growth kinetics

Adverse drug reaction reporting in a tertiary care teaching hospital in eastern India: a retrospective study

Background: Adverse drug reactions (ADRs) are one of the prime causes of morbidity and mortality, increase in hospital stay and socioeconomic burden on the patients. Periodic monitoring aids in formulating methods for safe usage of medicines in hospitals. This study was undertaken to study the patterns, assessment of causality, severity, preventability, body systems affected from ADRs received by the Pharmacovigilance cell, Department of Pharmacology between April 2018 to June 2019.Methods: The present study is an observational, retrospective, non-interventional analysis of voluntarily reported ADRs. Demography of patients, causative drugs, reactions, outcome, and severity are recorded. Data were analysed and expressed in numbers, percentages.Results: A total of 180 ADRs were spontaneously reported. Dermatology (42.8%), psychiatry (23.9%) and general medicine (18.3%) are the major departments reporting ADRs in our hospital. 60.6% reports were in males. The body system with maximum reactions is dermatological (51.1%). Drug class most commonly affected is anti-microbials (36.1%). Paracetamol (8.9%) is the most common drug with reactions. Causality assessment stated that 41.7% ADRs are probable and 58.3% were possible. Severity assessment showed 86.7% as mild and 13.3% as moderate. Preventability assessment stated that 93.3% ADRs not preventable, 5.6% probably preventable and 1.1% definitely preventable.Conclusions: The study provides a valuable insight with regards to the pattern of ADRs in our hospital. This will be useful in initiating a reporting culture, increase awareness, reducing under-reporting of ADR in our set up

Adverse cutaneous drug reactions reporting in a tertiary care teaching hospital in Eastern India: a retrospective study

Background: Any unwanted changes to mucous membrane, skin, its appendages and drug eruptions related adverse events are known as adverse cutaneous drug reaction (ACDR). It has 2-5% incidence in developing countries. The current study was undertaken to analyse adverse cutaneous drug reactions spectrum clinically, drugs responsible, assessment of causality, severity, and preventability in our setup.Methods: Current study was an observational, retrospective, non-interventional analysis of voluntarily reported ADRs forms, between April 2018 and January 2020.  All cutaneous ADRs reported within this period were identified. Data obtained were expressed in numbers, percentages.Results: 130 cutaneous ADRs was reported during the period of study. Fixed drug eruptions (30%) was the most common cutaneous reaction. The most common causal drug groups were antimicrobials (58.5%). Amongst antimicrobials, ornidazole (8.5%) was the most common drug. The most common drug in NSAID group was paracetamol (14.6%). The major drug causing ACDRs in our study was Paracetamol (14.6%). Assessment of causality revealed 37.7% were probable and 62.3% were possible reactions. Assessment of severity showed 78.5% as mild and 21.5% as moderate. Assessment of preventability showed that 6.1% probably preventable and 93.9% not preventable.Conclusions: Knowledge of the pattern of cutaneous reactions and the causative drugs guides us in early diagnosis of the condition, better management and associated decrease in morbidity, mortality. In the current study, the most common causal drug group were antimicrobials. The most common morphological pattern and drug causing ACDRs were fixed drug eruptions and paracetamol, respectively