323 research outputs found

    Radiating Aperture on Cylindrical Surfaces for End Fire Applications

    Get PDF

    Knowledge attitude and practice of haemovigilance among doctors in tertiary care hospital in Nagpur, Maharashtra, India

    Get PDF
    Background: Haemovigilance program of India was launched on December 2012 and is a comprehensive, and a well-structured approach to collect, collate, and analyse data to address the issues of adverse reactions associated with blood transfusion. The information thus collected would facilitate corrective and preventive actions to be taken to minimize the potential risk associated blood collection processing and transfusion to patients. Considering the deep concern over the under-reporting of transfusion reactions prevailing among the doctors, the present study was done to know the knowledge attitude and practice (KAP) of haemovigilance among doctors.Methods: The present study was a cross sectional questionnaire based study, which included doctors of a tertiary care hospital. The purpose of the questionnaire was to know awareness of doctors regarding haemovigilance programme of India. With this study we also tried to   identify the factors responsible for underreporting of transfusion reactions and to find out the possible ways to improve reporting of transfusion reactions.Results: (38.88%) and (30%) of the responders were aware of the haemovigilance programme and transfusion reaction reporting centre respectively. Reporting of transfusion reaction was poor 22.22% among the respondents. According to respondents creating awareness about haemovigilance by conducting continuing medical education (CMEs), and   training to healthcare professionals would lead to improvement in reporting of transfusion reactions. Complacency and ignorance were the main factors which discouraged transfusion reaction reporting by doctors.Conclusions: Increasing awareness of haemovigilance among doctors and training on reporting transfusion reactions would likely improve spontaneous reporting and help to strengthen the blood transfusion system

    Control of Buffer and Energy of a Wireless Device: Closed and Open Loop Approaches

    Get PDF
    We consider a decision problem faced by an energy limited wireless device that operates in discrete time. There is some external arrival to the device's transmit buffer. The possible decisions are a) to serve some of the buffer content, b) to reorder a new battery after serving the maximum possible amount that it can, and c) to remain idle so that the battery charge can increase owing to diffusion process (possible in some commercially available battery). We look at both open-loop and closed-loop control of the system. For the closed-loop control, we view the problem in the framework of Markov Decision Processes and address finite and infinite horizon discounted costs as well as average cost minimization problems. Without using any second order characteristics, we obtain results that include i) optimality of bang-bang control, ii) the optimality of threshold based policies, iii) parameteric monotonicity of the threshold, and iv) uniqueness of the threshold. For the open-loop control setting we use recent advances in application of multimodular functions to establish optimality of bracket sequence based control

    Fitting in a complex chi^2 landscape using an optimized hypersurface sampling

    Full text link
    Fitting a data set with a parametrized model can be seen geometrically as finding the global minimum of the chi^2 hypersurface, depending on a set of parameters {P_i}. This is usually done using the Levenberg-Marquardt algorithm. The main drawback of this algorithm is that despite of its fast convergence, it can get stuck if the parameters are not initialized close to the final solution. We propose a modification of the Metropolis algorithm introducing a parameter step tuning that optimizes the sampling of parameter space. The ability of the parameter tuning algorithm together with simulated annealing to find the global chi^2 hypersurface minimum, jumping across chi^2{P_i} barriers when necessary, is demonstrated with synthetic functions and with real data

    Nuclear Activity and the Conditions of Star-formation at the Galactic Center

    Full text link
    The Galactic Center is the closest galactic nucleus that can be studied with unprecedented angular resolution and sensitivity. We summarize recent basic observational results on Sagittarius A* and the conditions for star formation in the central stellar cluster. We cover results from the radio, infrared, and X-ray domain and include results from simulation as well. From (sub-)mm and near-infrared variability and near-infrared polarization data we find that the SgrA* system (supermassive black hole spin, a potential temporary accretion disk and/or outflow) is well ordered in its geometrical orientation and in its emission process that we assume to reflect the accretion process onto the supermassive black hole (SMBH).Comment: 11 pages, 4 figures, 1 table; published in PoS-SISSA Proceedings of the: Frontier Research in Astrophysics - II, 23-28 May 2016, Mondello (Palermo), Ital

    Item analysis as tool to validate multiple choice question bank in pharmacology

    Get PDF
    Background: Multiple choice questions (MCQs) are a common method for formative and summative assessment of medical students. Item analysis enables identifying good MCQs based on difficulty index (DIF I), discrimination index (DI), distracter efficiency (DE). The objective of this study was to assess the quality of MCQs currently in use in pharmacology by item analysis and develop a MCQ bank with quality items.Methods: This cross-sectional study was conducted in 148 second year MBBS students at NKP Salve institute of medical sciences from January 2018 to August 2018. Forty MCQs twenty each from the two term examination of pharmacology were taken for item analysis A correct response to an item was awarded one mark and each incorrect response was awarded zero. Each item was analyzed using Microsoft excel sheet for three parameters such as DIF I, DI, and DE.Results: In present study mean and standard deviation (SD) for Difficulty index (%) Discrimination index (%) and Distractor efficiency (%) were 64.54±19.63, 0.26±0.16 and 66.54±34.59 respectively. Out of 40 items large number of MCQs has acceptable level of DIF (70%) and good in discriminating higher and lower ability students DI (77.5%). Distractor efficiency related to presence of zero or 1 non-functional distrator (NFD) is 80%.Conclusions: The study showed that item analysis is a valid tool to identify quality items which regularly incorporated can help to develop a very useful, valid and a reliable question bank

    Experimental Results of Concurrent Learning Adaptive Controllers

    Get PDF
    Commonly used Proportional-Integral-Derivative based UAV flight controllers are often seen to provide adequate trajectory-tracking performance only after extensive tuning. The gains of these controllers are tuned to particular platforms, which makes transferring controllers from one UAV to other time-intensive. This paper suggests the use of adaptive controllers in speeding up the process of extracting good control performance from new UAVs. In particular, it is shown that a concurrent learning adaptive controller improves the trajectory tracking performance of a quadrotor with baseline linear controller directly imported from another quadrotors whose inertial characteristics and throttle mapping are very di fferent. Concurrent learning adaptive control uses specifi cally selected and online recorded data concurrently with instantaneous data and is capable of guaranteeing tracking error and weight error convergence without requiring persistency of excitation. Flight-test results are presented on indoor quadrotor platforms operated in MIT's RAVEN environment. These results indicate the feasibility of rapidly developing high-performance UAV controllers by using adaptive control to augment a controller transferred from another UAV with similar control assignment structure.United States. Office of Naval Research. Multidisciplinary University Research Initiative (Grant N000141110688)National Science Foundation (U.S.). Graduate Research Fellowship Program (Grant 0645960)Boeing Scientific Research Laboratorie

    Experimental Indicators of Accretion Processes in Active Galactic Nuclei

    Full text link
    Bright Active Galactic Nuclei are powered by accretion of mass onto the super massive black holes at the centers of the host galaxies. For fainter objects star formation may significantly contribute to the luminosity. We summarize experimental indicators of the accretion processes in Active Galactic Nuclei (AGN), i.e., observable activity indicators that allow us to conclude on the nature of accretion. The Galactic Center is the closest galactic nucleus that can be studied with unprecedented angular resolution and sensitivity. Therefore, here we also include the presentation of recent observational results on Sagittarius A* and the conditions for star formation in the central stellar cluster. We cover results across the electromagnetic spectrum and find that the Sagittarius A* (SgrA*) system is well ordered with respect to its geometrical orientation and its emission processes of which we assume to reflect the accretion process onto the super massive black hole.Comment: 16 pages, 4 figures, conference proceeding: Accretion Processes in Cosmic Sources - APCS2016 - 5-10 September 2016, Saint Petersburg, Russi
    corecore