2,340 research outputs found
Application of Qualitative Methods in Health Research: An Overview
Qualitative research is type of formative research that includes specialized techniques for obtaining in-depth responses about what people think and how they feel. It is seen as the research that seeks answer to the questions in the real world. Qualitative researchers gather what they see, hear, read from people and places, from events and activities, with the purpose to learn about the community and to generate new understanding that can be used by the social world. Qualitative research have often been conducted to answer the question “why” rather than “what”. A purpose of qualitative research is the construction of new understanding. Here, we present an overview of application of qualitative methods in health research. We have discussed here the different types of qualitative methods and how we and others have used them in different settings/scenarios; sample size and sampling techniques; analysis of qualitative data; validity in qualitative research; and ethical issues
Multi-echelon Repair Inventory Systems: Select Issues in Modular Electronic Equipment
Flow of modules/printed circuit boards (PCBs) in a multi-echelon repair inventory system pertaining to modular electronic equipment for large maintenance organisations having large inventory in range and depth, like defence has been critically examined using a case study. Desirable features of the proposed system are identified and a general framework suggested for examining its feasibility and implementation in an organisation. An analytical model with an objective to reduce number of echelons is also suggested and compared with the base model. It is suggested that various models can be compared through simulation and their performance measured using balanced scorecard approach.Defence Science Journal, 2010, 60(5), pp.514-524, DOI:http://dx.doi.org/10.14429/dsj.60.57
An Adaptive Color Image Segmentation
A novel Adaptive Color Image Segmentation (ACIS) System for color image segmentation is presented. The proposed ACIS system uses a neural network with architecture similar to the multilayer perceptron (MLP) network. The main difference is that neurons here uses a multisigmoid activation function. The multisigmoid function is the key for segmentation. The number of steps i.e. thresholds in the multisigmoid function are dependant on the number of clusters in the image. The threshold values for detecting the clusters and their labels are found automatically from the first order derivative of histograms of saturation and intensity in the HSV color space. Here, the main use of neural network is to detect the number of objects automatically from an image. The advantage of this method is that no a priori knowledge is required to segment the color image. ACIS label the objects with their mean colors. The algorithm is found to be reliable and works satisfactorily on different kinds of color images. Experimental results show that the performance of ACIS is robust on noisy images also
Implications of time-dependent molecular chemistry in metal-poor dwarf stars
Binary molecules such as CO, OH, CH, CN, and C are often used as
abundance indicators in stars. These species are usually assumed to be formed
in chemical equilibrium. The time-dependent effects of hydrodynamics can affect
the formation and dissociation of these species and may lead to deviations from
chemical equilibrium. We aim to model departures from chemical equilibrium in
dwarf stellar atmospheres by considering time-dependent chemical kinetics
alongside hydrodynamics and radiation transfer. We examine the effects of a
decreasing metallicity and an altered C/O ratio on the chemistry when compared
to the equilibrium state. We used the radiation-(magneto)hydrodynamics code
CO5BOLD, and its own chemical solver to solve for the chemistry of 15 species
and 83 reactions. The species were treated as passive tracers and were advected
by the velocity field. The steady-state chemistry was also computed to isolate
the effects of hydrodynamics.
In most of the photospheres in the models we present, the mean deviations are
smaller than dex, and they generally appear above . The
deviations increase with height because the chemical timescales become longer
with decreasing density and temperature. A reduced metallicity similarly
results in longer chemical timescales and in a reduction in yield that is
proportional to the drop in metallicity; a decrease by a factor in
metallicity loosely corresponds to an increase by factor in chemical
timescales. As both CH and OH are formed along reaction pathways to CO, the C/O
ratio means that the more abundant element gives faster timescales to the
constituent molecular species. Overall, the carbon enhancement phenomenon seen
in very metal-poor stars is not a result of an improper treatment of molecular
chemistry for stars up to a metallicity as low as [Fe/H] = .Comment: 29 page
Population eruption of sunset shell Siliqua radiata (Linnaeus, 1758) along Versova beach in Mumbai
Sudden population eruption of Siliqua radiata during monsoon months (June-August 2008) was
observed along Versova beach in Mumbai. Relationship between shell length (SL) and total weight
(TW) was TW = 0.0001137 * SL 2.67922, shell length (SL) and meat weight (MW) was MW = 0.0000237
* SL 2.91756. S. radiata had isometric growth. The average density was estimated as 14 per square meter
and the biomass was 153 g.m-2. The proportion of meat was 60%. Analysis of meat showed high amount
of heavy metals namely copper, cadmium and arsenic
Fishery and biology of white sardine, Escualosa thoracata (Valenciennes) at Versova, Bombay
Gill net fishery exclusively for the white sardine, Escualosa
thoracata, which started in mid eighties at Versova, is described.
During 1987-88 to 1991-92 period the annual average landing of the
species was 202.2 tons with year to year fluctuations. The peak fishing
season was during April-May. The size range of the species in the gill
net was 41-105 m
Maintenance, Repair, and Overhaul Performance Indicators for Military Aircraft
Modern day military and commercial aircraft systems are an integration of a large number of sub-systems and components. Each of these systems has different reliability characteristics and different probability distributions governing their failure rates. Space constraints and structural layout of the aircraft govern the position of each component. The accessibility, reliability, and snag diagnostic-ability determines the maintainability of the aircraft. The peculiarities involved in aircraft maintenance are discussed and performance measurement indices for O, I and D level maintenance are presented in this paper. These performance measurement indices are intended for use by aircraft maintenance managers for instituting process improvements for achieving best flight and maintenance safety records, improve operational availability of the aircraft and reduce costs.Defence Science Journal, 2012, 62(2), pp.83-89, DOI:http://dx.doi.org/10.14429/dsj.62.88
Thermal stresses in functionally graded hollow sphere due to non-uniform internal heat generation
In this article, the thermal stresses in a hollow thick sphere of functionally graded material subjected to non-uniform internal heat generation are obtained as a function of radius to an exact solution by using the theory of elasticity. Material properties and heat generation are assumed as a function of radius of sphere and Poisson’s ratio as constant. The distribution of thermal stresses for different values of the powers of the module of elasticity and varying power law index of heat generation is studied. The results are illustrated numerically and graphically
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