1,027 research outputs found

    The Linear Model under Mixed Gaussian Inputs: Designing the Transfer Matrix

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    Suppose a linear model y = Hx + n, where inputs x, n are independent Gaussian mixtures. The problem is to design the transfer matrix H so as to minimize the mean square error (MSE) when estimating x from y. This problem has important applications, but faces at least three hurdles. Firstly, even for a fixed H, the minimum MSE (MMSE) has no analytical form. Secondly, the MMSE is generally not convex in H. Thirdly, derivatives of the MMSE w.r.t. H are hard to obtain. This paper casts the problem as a stochastic program and invokes gradient methods. The study is motivated by two applications in signal processing. One concerns the choice of error-reducing precoders; the other deals with selection of pilot matrices for channel estimation. In either setting, our numerical results indicate improved estimation accuracy - markedly better than those obtained by optimal design based on standard linear estimators. Some implications of the non-convexities of the MMSE are noteworthy, yet, to our knowledge, not well known. For example, there are cases in which more pilot power is detrimental for channel estimation. This paper explains why

    Major Indian spices- An introspection on variability in quality

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    Indian spices like black pepper, cardamom, ginger, turmeric and cinnamon are valued for their culinary and nutraceutical properties. The quality attributes that impart these properties are essential oil, oleoresin and the aroma/pungent principles. Variability in essential oil constituents of black pepper, relevance of bulk density, codex standards and role of phenolics in deciding quality traits possess great relevance in academic and industrial applications. Curing of turmeric and maturity at harvest play a crucial role in drying and curcumin content. Geographical location has great relevance in deciding the curcumin content of turmeric. Coumarin content of cinnamon and cassia has implications in industrial application. This article provides an introspection in to the research programmes on quality attributes of spices carried out at ICAR-Indian Institute of Spices Research for the last three decades in comparison with international scenario

    GiRaFFE: An Open-Source General Relativistic Force-Free Electrodynamics Code

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    We present GiRaFFE, the first open-source general relativistic force-free electrodynamics (GRFFE) code for dynamical, numerical-relativity generated spacetimes. GiRaFFE adopts the strategy pioneered by McKinney and modified by Paschalidis and Shapiro to convert a GR magnetohydrodynamic (GRMHD) code into a GRFFE code. In short, GiRaFFE exists as a modification of IllinoisGRMHD, a user-friendly, open-source, dynamical-spacetime GRMHD code. Both GiRaFFE and IllinoisGRMHD leverage the Einstein Toolkit's highly-scalable infrastructure to make possible large-scale simulations of magnetized plasmas in strong, dynamical spacetimes on adaptive-mesh refinement (AMR) grids. We demonstrate that GiRaFFE passes a large suite of both flat and curved-spacetime code tests passed by a number of other state-of-the-art GRFFE codes, and is thus ready for production-scale simulations of GRFFE phenomena of key interest to relativistic astrophysics.Comment: 23 pages, 4 figures. Consistent with published versio

    Building leadership capacity and future leaders in operational research in low-income countries: why and how?

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    Very limited operational research (OR) emerges from programme settings in low-income countries where the greatest burden of disease lies. The price paid for this void includes a lack of understanding of how health systems are actually functioning, not knowing what works and what does not, and an inability to propose adapted and innovative solutions to programme problems. We use the National Tuberculosis Control Programme as an example to advocate for strong programme-level leadership to steer OR and build viable relationships between programme managers, researchers and policy makers. We highlight the need to create a stimulating environment for conducting OR and identify some of the main practical challenges and enabling factors at programme level. We focus on the important role of an OR focal point within programmes and practical approaches to training that can deliver timely and quantifiable outputs. Finally, we emphasise the need to measure successful OR leadership development at programme level and we propose parameters by which this can be assessed. This paper 1) provides reasons why programmes should take the lead in coordinating and directing OR, 2) identifies the practical challenges and enabling factors for implementing, managing and sustaining OR and 3) proposes parameters for measuring successful leadership capacity development in OR

    Dermatophytes from Apparently Healthy Toe-webs of Service Personnel Stationed in Northeastren Region of India

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    Apparently healthy toe-webs of 230 individuals belonging to various Army units stationed India were studied for dermatophytes. 35 were found positive. This revealed the presence of 28 Trichophyton mentagrophytes, 4 Epidermophyton floccosum, 2 Microsporum gypseum and 1 T. rubrum

    Junior Recital:Patrick T. Keelan & Zachariah R. Oostema, Percussion

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    Kemp Recital Hall Saturday Afternoon November 3, 2007 5:00p.m

    Dietary supplementation of Cinnamomumverum J. Presl and Curcuma longa L. extract on growth performance, antioxidant and metabolic enzymes activities in experimental rats

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    242-248Cinnamomumverum J. Presl and Curcuma longa L. have many biologically active metabolites, such as sterpenoids, phenolics with proven health benefits. The present study was undertaken to analyze the effect of cinnamon and turmeric extract on growth, blood parameters, and metabolic enzyme activities of albino Wistar rats. Methanol extract of cinnamon and turmeric mixture was supplemented in rat feed at 2.5 and 5% concentration, respectively and administered for 30 days. During the course of study, body weight, feed given, feed consumed data were collected at regular intervals. After the experimental period, animals were sacrificed, tissues separated, homogenized and assayed for the activity of catalase, superoxide dismutase (SOD), glutathione-s-transferase (GST), lactate dehydrogenase (LDH), malate dehydrogenase (MDH), alanine aminotransferase (AAT) and aspartate aminotransferase (AST). The results showed significant increase in liver catalase activity of treated animals and no significant changes in LDH, MDH, ALT and AST. No abnormalities were observed in the histopathology staining of tissue section. Overall, output of the present study could be useful for production of spices based antioxidant rich products for human health

    Impact of migration on Kerala's economy and society

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    This research is first of its kind for Kerala, being the first migration study that covers the entire state and encompasses both measurement as well as analysis of the various types and facets of migration. Migration has been the single-most dynamic factor in the otherwise dreary development scenario of Kerala in the last quarter of the twentieth century. Kerala is approaching the end of the millennium with a little cheer in many people's homes, a major contributing factor for which has been migration. Migration has contributed more to poverty alleviation in Kerala than any other factor, including agrarian reforms, trade union activities and social welfare legislation. The study shows that nearly 1.5 million Keralites now live outside India. They send home more than Rs.4,000 million a year by way of remittances. Three-quarters of a million former emigrants have come back. They live mostly on savings, work experience, and skills brought with them from abroad. More than a million families depend on internal migrants'earnings for subsistence, children's education and other economic requirements. Whereas the educationally backward Muslims from the Thrissur-Malappuram region provide the backbone of emigration, it is the educationally forward Ezhawas, Nairs and Syrian Christians from the former Travancore-Cochin State who form the core of internal migration. The paper also analyses the determinants and consequences of internal and external migration. It offers suggestions for policy formulation for the optimum utilization of remittances sent home by the emigrants and the expertise brought back by the return migrants. Migration in Kerala began with demographic expansion, but it won't end with demographic contraction. Kerala has still time to develop itself into an internally self-sustaining economy. The prevailing cultural milieu of Kerala in which its people believe that anything can be achieved through agitation and any rule can be circumvented with proper political connections, must change and be replaced by a liberalised open economy with strict and definite rules of the game. JEL Classification: J21, J2
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