Multi-dimensional radiative transfer to analyze Hanle effect in Ca {\sc ii} K line at 3933 \AA\,

Radiative transfer (RT) studies of the linearly polarized spectrum of the Sun (the second solar spectrum) have generally focused on the line formation, with an aim to understand the vertical structure of the solar atmosphere using one-dimensional (1D) model atmospheres. Modeling spatial structuring in the observations of the linearly polarized line profiles requires the solution of multi-dimensional (multi-D) polarized RT equation and a model solar atmosphere obtained by magneto-hydrodynamical (MHD) simulations of the solar atmosphere. Our aim in this paper is to analyze the chromospheric resonance line Ca {\sc ii} K at 3933 \AA\ using multi-D polarized RT with Hanle effect and partial frequency redistribution in line scattering. We use an atmosphere which is constructed by a two-dimensional snapshot of the three-dimensional MHD simulations of the solar photosphere, combined with columns of an 1D atmosphere in the chromosphere. This paper represents the first application of polarized multi-D RT to explore the chromospheric lines using multi-D MHD atmospheres, with PRD as the line scattering mechanism. We find that the horizontal inhomogeneities caused by MHD in the lower layers of the atmosphere are responsible for strong spatial inhomogeneities in the wings of the linear polarization profiles, while the use of horizontally homogeneous chromosphere (FALC) produces spatially homogeneous linear polarization in the line core

Effect of cross-redistribution on the resonance scattering polarization of O {\sc i} line at 1302 \AA\,

Oxygen is the most abundant element on the Sun after Hydrogen and Helium. The intensity spectrum of resonance lines of neutral Oxygen namely O {\sc i} (1302, 1305 and 1306 \AA\,) has been studied in the literature for chromospheric diagnostics. In this paper we study the resonance scattering polarization in the O {\sc i} line at 1302 \AA\, using two-dimensional radiative transfer in a composite atmosphere constructed using a two-dimensional magneto-hydrodynamical snapshot in the photosphere and columns of the one-dimensional FALC atmosphere in the chromosphere. The methods developed by us recently in a series of papers to solve multi-dimensional polarized radiative transfer have been incorporated in our new code POLY2D which we use for our analysis. We find that multi-dimensional radiative transfer including XRD effects is important in reproducing the amplitude and shape of scattering polarization signals of the O {\sc i} line at 1302 \AA\,

Polarized Line Formation in Multi-Dimensional Media.III. Hanle Effect with Partial Frequency Redistribution

In the previous two papers, namely, \citet{anuknn11} and \citet{anuetal11} we solved the polarized radiative transfer (RT) equation in multi-dimensional (multi-D) geometries, with partial frequency redistribution (PRD) as the scattering mechanism. We assumed Rayleigh scattering as the only source of linear polarization ($Q/I, U/I$) in both these papers. In this paper we extend these previous works to include the effect of weak oriented magnetic fields (Hanle effect) on line scattering. We generalize the technique of Stokes vector decomposition in terms of the irreducible spherical tensors $\mathcal{T}^K_Q$, developed in \citet{anuknn11}, to the case of RT with Hanle effect. A fast iterative method of solution (based on the Stabilized Preconditioned Bi-Conjugate-Gradient technique), developed in \citet{anuetal11}, is now generalized to the case of RT in magnetized three-dimensional media. We use the efficient short-characteristics formal solution method for multi-D media, generalized appropriately to the present context. The main results of this paper are the following: (1) A comparison of emergent $(I, Q/I, U/I)$ profiles formed in one-dimensional (1D) media, with the corresponding emergent, spatially averaged profiles formed in multi-D media, shows that in the spatially resolved structures, the assumption of 1D may lead to large errors in linear polarization, especially in the line wings. (2) The multi-D RT in semi-infinite non-magnetic media causes a strong spatial variation of the emergent $(Q/I, U/I)$ profiles, which is more pronounced in the line wings. (3) The presence of a weak magnetic field modifies the spatial variation of the emergent $(Q/I, U/I)$ profiles in the line core, by producing significant changes in their magnitudes.Comment: 31 pages, 14 figures, Submitted to ApJ, Under revie

Design and development of certification compliance tool for airborne systems.

Certification compliance check for airborne software is very critical as it aids in the certification of the software. Since this compliance check is performed manually which is time-consuming and erroneous, an in-house developed Certification Compliance Tool (CCT) helps in checking the compliance as per RTCA DO-178B/C and generate artifacts depicting the magnitude of compliance. In order to generate the magnitude of compliance for the artifacts with respect to the Civil Aerospace Certification standard, RTCA DO-178B/C, an effective parsing technique is required to be incorporated to parse the artifact/s and generate compliance metric for the artifact/s. In this paper we propose a novel approach used in the design and development of an effective and efficient parsing technique incorporated in the indigenous software tool CCT used for compliance check. The tool checks the ratio of compliance of the artifacts generated across various phases of Software Development Life Cycle (SDLC) process involved in the development of Safety-Critical software as per RTCA DO-178B/C. The indigenous tool accepts these artifacts as inputs and based on the software criticality level, it analyzes the compliance of these artifacts with the guidelines provided and recommended by RTCA DO-178B/C. The output of the tool provides the percentage of compliance of the artifacts that helps in accessing the Certification capabilities of the developed software. The percentage of compliance predicts the acceptance or rejection probabilities of the software being certified by the Certification Agency. The certification parser is developed using Python modules like Pywin32, Pypdf parsers and different approaches for Natural language processing using Python Natural Language Toolkit (NLTK). The in-house tool replaces the manual effort by an individual/s which may be erroneous and impact the time-schedule, which compromises the software safety. The integration of the tool with commercial tools will help in analyzing the report/ documentation content with respect to the certification

HCIFR: Hierarchical Clustering and Iterative Filtering Routing Algorithm for Wireless Sensor Networks

The hierarchical clustering and iterative filtering algorithms are combined to form an energy efficient routing algorithm which supports in improved performance, efficient routing at the time of link failure, collusion robust and secure data aggregation. The idea of combining these two algorithms which may lead to improved performance. Initially clusters are formed by neighborhood. The cluster is a combination of one clusterhead, two deputy clusterheads and cluster members. This system uses a Hierarchical clustering algorithm for efficient data transmission to their clusterhead by cluster members. The clusterhead aggregate the collected data and check for trustworthiness. The data is aggregated by clusterhead using the iterative filtering algorithm and resistant to collusion attacks. Simulation results depict the average energy consumption, throughput, packet drops and packet delivery under the influence of proposed algorithm

Combining depth and intensity images to produce enhanced object detection for use in a robotic colony

Robotic colonies that can communicate with each other and interact with their ambient environments can be utilized for a wide range of research and industrial applications. However amongst the problems that these colonies face is that of the isolating objects within an environment. Robotic colonies that can isolate objects within the environment can not only map that environment in de-tail, but interact with that ambient space. Many object recognition techniques ex-ist, however these are often complex and computationally expensive, leading to overly complex implementations. In this paper a simple model is proposed to isolate objects, these can then be recognize and tagged. The model will be using 2D and 3D perspectives of the perceptual data to produce a probability map of the outline of an object, therefore addressing the defects that exist with 2D and 3D image techniques. Some of the defects that will be addressed are; low level illumination and objects at similar depths. These issues may not be completely solved, however, the model provided will provide results confident enough for use in a robotic colony

Analysis of cutaneous adverse drug reactions in a tertiary care teaching hospital

Background: Cutaneous Adverse Drug Reaction (CADR) is considered as one of the reasons for discontinuation of drug as well as medication non-adherence. This study analyses the common drugs causing CADR, clinical spectrum of different types of CADR, causality and drugs causing severe CADR.Methods: This was a retrospective cross-sectional observational study conducted by the Department of Pharmacology, Coimbatore Medical College, Coimbatore, Tamil Nadu, India. The study was conducted using data collected in CDSCO’s ADR reporting forms with CADR from June 2015 to July 2017. Patient’s information, details related to adverse drug reaction, suspected medication details, concomitant medication history, causality and seriousness were recorded.Results: A total of 102 CADR were evaluated in this study. The mean age of sample was 37.21±20.33 years. Maximum number of cases was in the age group of 40-49 years. Male to female ratio was 0.96:1. The commonly incriminated drugs causing CADR were antimicrobial agents. Ciprofloxacin (21.57%), phenytoin (9.8%), diclofenac sodium (6.86%), anti-snake venom (6.86%) and vancomycin (3.92%) were the common drugs implicated in CADR. Maculopapular rash and itching were the most common CADR. Anticonvulsants especially phenytoin was commonly associated with severe CADR.Conclusions: The present study has made an impact on all departments of this institution and awareness has been created about spontaneous reporting of all adverse drug reactions in CDSCO ADR reporting forms to the pharmacovigilance centres. Thus, sound knowledge about the adverse drug reactions may decrease the occurrence of drug induced morbidity and mortality.