Ensuring Software Quality-Experiences of Testing Tejas Airdata Software

Two major safety-critical elements of the onboard software for the Tejas digital flight controlcomputer software are the control laws and the airdata algorithm. The airdata algorithm computesessential parameters like static and dynamic pressures, altitude, speed, angle of attack, etc fromthe airdata sensor input. These parameters are used by the control laws to stabilise the aircraftand to provide the required uniform handling qualities over the complete flight envelope. Thealgorithm is provided by the Control Law Design Team and coded by the Software Design Groupof Software House, ADA, Bangalore, in Ada language. The Independent Verification and ValidationGroup is responsible for ensuring that the software is bug-free and certifiable. A non-real time(NRT) test methodology has been developed in-house to stress test the onboard software. Thispaper gives an overview of the methodology used to carry out the NRT test of the airdataalgorithm and some of the testing experiences

Effect of sowing dates and varieties on soybean performance in Vidarbha region of Maharashtra, India

oybean production is widely fluctuating in response to agro-environmental conditions year to year in Vidarbha region. Weather variations are the major determinants of soybean growth and yield. It is also important to study the response of suitable soybean varieties to varying weather parameters. So a field investigation was carried out to study the crop weather relationship of soybean and to optimize the sowing date with different soybean varie-ties. The results revealed that soybean crop sown up to 27th MW accumulated higher growing degree days (1640.5 0C day), photothermal units (20498.1 0C day hour) and recorded significantly higher seed yield (839 kg ha-1) and biological yield (2773 kg ha-1) with maximum heat use efficiency (0.51 kg ha-1°C day-1) and water productivity (2.49 kg ha-mm-1). Later sowings i.e. 30th MW sowing caused decreased amount of rainfall and increased maximum temperature regime across the total growing period with consequently lower seed yield (530 kg ha-1), GDD (1539.2 0C day), PTU (18689.9 0C day hour), heat use efficiency (0.34kg ha-1 °Cday-1) and water productivity (2.05kg ha-mm-1). Soybean variety TAMS 98-21 recorded significantly higher seed yield (734 kg ha-1) and highest biological yield (2649 kg ha-1) with maximum heat use efficiency (0.44 kg ha-1 °C day-1), GDD (1650.5 0C day ) and water productivity (2.41 kg ha-mm-1). Thus, the results of this study illustrated the importance of early sowing with suitable variety of soybean and indicates that sowing upto 27th MW with variety TAMS 98-21 is optimum for maximizing the yield in the Akola region of Vidarbha

PACLITAXEL DISPOSITION STUDIES USING P-GP INHIBTOR & INDUCER BY SINGLE PASS INTESTINAL PERFUSION IN RATS

Objective: The present research work aims to study the intestinal transport of Paclitaxel and to predict its human intestinal permeability and fraction absorbed using SPIP Permeability Coefficient and the effect of P-gp modulators on Paclitaxel were observed in anaesthetized rats. Methods: Jejunal segment was used for performing Single Pass Intestinal Perfusion. The rationale for the selection of jejenum is due to the overexpression of P-glycoprotein when compared with other segments. Drug solution (150µg/ml) in phosphate buffer saline was perfused at a flow rate of 0.2ml/min.Besides,P-gp inhibitor verapamil(200 µg/ml) and inducer Rifampicin (60mg/ml) were coperfused with Paclitaxel to detect its disposition characteristics affected by P-gp .Drug concentrations in samples were analyzed using HPLC. Stability studies were conducted to ensure the loss of Paclitaxel due to absorption. Results: The effective permeability value of Paclitaxel (150µg/ml) in the jejunal segment was found to be lower due to the efflux mediated by P-gp.When coperfused with verapamil its permeability significantly enhanced as it is a P-gp inhibitor and vice versa with Rifampicin which is a P-gp inducer. Subsequently the human intestinal permeability was estimated considering Peff(human) =1.04 Peff(rat)-0.0003. Conclusion: P-Glycoprotein mediated drug resistance is one of the serious limitations of Paclitaxel efficacy and jejunal segment is found to have major MDR expression. The Peff value of Paclitaxel was found to be increased upon the Coperfusion with verapamil and similarly reduced with Rifampicin which are inhibitors & inducers respectively indicating Paclitaxel is efficiently transported by P-gp. Hence, Paclitaxel satisfies all the prerequisites to be a P-gp substrate.   Keywords: Paclitaxel, Intestinal permeability, Single pass intestinal perfusion, P-glycoprotein, RP-HPLC

Parallel Differential Evolution approach for Cloud workflow placements under simultaneous optimization of multiple objectives

International audienceThe recent rapid expansion of Cloud computing facilities triggers an attendant challenge to facility providers and users for methods for optimal placement of workflows on distributed resources, under the often-contradictory impulses of minimizing makespan, energy consumption, and other metrics. Evolutionary Optimization techniques that from theoretical principles are guaranteed to provide globally optimum solutions, are among the most powerful tools to achieve such optimal placements. Multi-Objective Evolutionary algorithms by design work upon contradictory objectives, gradually evolving across generations towards a converged Pareto front representing optimal decision variables – in this case the mapping of tasks to resources on clusters. However the computation time taken by such algorithms for convergence makes them prohibitive for real time placements because of the adverse impact on makespan. This work describes parallelization, on the same cluster, of a Multi-Objective Differential Evolution method (NSDE-2) for optimization of workflow placement, and the attendant speedups that bring the implicit accuracy of the method into the realm of practical utility. Experimental validation is performed on a real-life testbed using diverse Cloud traces. The solutions under different scheduling policies demonstrate significant reduction in energy consumption with some improvement in makespan

Structural and Dielectric Characterization of La Modified PZT (52/48) Nano Ceramic Material for Electronic Applications

The objective of the presented work is to investigate the effects of varying concentration of La as hard dopant on structural, morphological and dielectric properties of lead zirconium titanate (PZT). The base material PZT was prepared by sol-gel technique on lab scale to reduce the injection of sintering defects. After addition of varying weight percentage of La, the different composite materials were analyzed under scanning electron microscope to study the structural modifications taking place. X-Ray diffraction patterns were studied in combination with variation of dielectric constant with temperature and frequency. it is observed that a single phase perovskite structure with tetragonal phase is formed for all compositions of PLZT. The dielectric constant of undoped PZT is found to be 11,300 at a temperature of 500OC and frequency of 100Hz. The results further indicate that the dielectric properties of the pure-phase PZT are better than La doped PZT at higher temperature

A prediction model for the lost wax process through fuzzy-based artificial neural network

Abstract The application of investment casting process is rapidly increasing, specifically for near net shape manufacturing of complex and small engineering components. The process begins with making of wax patterns, thereafter employing a precision mould, dewaxing, pouring molten alloy and knocking the shell, followed by minor finishing operations. This study is about predicting the quality of responses of the wax patterns namely linear shrinkage and surface roughness using fuzzy-based artificial neural network. The process parameters considered are injection temperature, injection pressure and holding time, and experiments have been performed as per Taguchi's L 18 orthogonal array. As optimum parameter levels were different for both the responses, fuzzy logic reasoning has been used to combine all the objectives and transform the experimental results into single performance index known as multi-response performance index. Later, modelling of the process has been done using artificial neural network with experimental process parameters as inputs and multi-response performance index as output obtained from fuzzy modelling. Further, experiments have been conducted at random combination of parameter levels to validate the developed model, and it has been found that the actual results agreed well with that of the predicted value on the basis of mean absolute percentage error and correlation plots

A prediction model for the lost wax process through fuzzy-based artificial neural network

Abstract The application of investment casting process is rapidly increasing, specifically for near net shape manufacturing of complex and small engineering components. The process begins with making of wax patterns, thereafter employing a precision mould, dewaxing, pouring molten alloy and knocking the shell, followed by minor finishing operations. This study is about predicting the quality of responses of the wax patterns namely linear shrinkage and surface roughness using fuzzy-based artificial neural network. The process parameters considered are injection temperature, injection pressure and holding time, and experiments have been performed as per Taguchi's L 18 orthogonal array. As optimum parameter levels were different for both the responses, fuzzy logic reasoning has been used to combine all the objectives and transform the experimental results into single performance index known as multi-response performance index. Later, modelling of the process has been done using artificial neural network with experimental process parameters as inputs and multi-response performance index as output obtained from fuzzy modelling. Further, experiments have been conducted at random combination of parameter levels to validate the developed model, and it has been found that the actual results agreed well with that of the predicted value on the basis of mean absolute percentage error and correlation plots

Effect of moisture stress, plant population density and pathogen inoculation on charcoal stalk rot of sorghum

The effects of moisture deficit stress, plant population density and pathogen inoculation technique on charcoal stalk rot in the sorghum hybrid CSH 6 were studied in the 1980–81 and 1981–82 post-rainy seasons at three locations in India. Incidence and severity of charcoal rot caused by Macrophomina phaseolina were compared in three plant population densities, subjected to different moisture stress regimes created by withholding irrigation at various plant growth stages. Natural infections were compared to artificial inoculation with M. phaseolina. Combinations of moisture stress, plant population and inoculation treatments were compared to identify the combination most likely to develop maximum disease. Lodging, the first external symptom of charcoal rot, was significantly correlated with other disease symptoms used to measure charcoal rot, such as soft stalk, number of nodes crossed by M. phaseolina infection, root damage and plant senescence. In both seasons the highest incidence of lodging occurred when moisture stress was induced at the ‘flag leaf visible in the whorl’ growth stage. The greatest incidence of the disease was recorded in the highest plant population (266 700 plant ha-) at all three locations. No significant differences were found between artificially and naturally inoculated treatments. The maximum number of lodged plants was found at a density of 266 700 plants ha-1 when moisture stress was induced at the ‘flag leaf visible in the whorl’ growth stage