Minimized Group Delay FIR Low Pass Filter Design Using Modified Differential Search Algorithm, Journal of Telecommunications and Information Technology, 2023, nr 3

Designing a finite impulse response (FIR) filter with minimal group delay has proven to be a difficult task. Many research studies have focused on reducing pass band and stop band ripples in FIR filter design, often overlooking the optimization of group delay. While some works have considered group delay reduction, their approaches were not optimal. Consequently, the achievement of an optimal design for a filter with a low group delay value still remains a challenge. In this work, a modified differential search optimization algorithm has been used for the purpose of designing a minimal group delay FIR filter. The results obtained have been compared with the classical techniques and they turned out to be promising

Biofuels for Defence Use: Past, Present And Future

Defence sector desires to attain energy self-sufficiency and security. In recent years, emergence of biofuel as an alternative source has raised the hopes of Defence. Ethanol and bio-diesel are currently being used as blends in different parts of the world. While, bio-diesel is mostly being blended in 2-20% in different parts of the world, ethanol blending has reached upto 85%. Owing to the sustainability reasons, the choice of feedstock for ethanol production is gradually changing from corn to lignocelluloses biomass. Jatropha curcas, is still the choice feedstockfor bio-diesel in most third world countries. This institute has put in rigrous efforts to identify high yielding varieties of Jatropha, improving its yield, standardizing trans-esterification to obtain high quality bio-diesel and its trials and testing in various vehicles and equipment. Second generation biofuels using biomass such as farm and forest wastes as feedstocks are promising in terms of their overall sustainability and volume produced. They can be used as drop in fuels. However, time is required to utilize their potential fully. Algae, the third generation biofuel feedstock still needs extensive R&D to make it economically sustainable. Whatever, the technology used, defence forces will accept any biofuel, which should be available constantly and priced below the existing petroleum fuels. The scope of producing by-products and finding a lucarative market for these products can ensure that prices ofbiofuels remain lower than the petroleum fuel

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Quadrature mirror filter bank design based on hybrid bee colony technique

This paper proposed a modified evolutionary technique formed by the hybridization of the bee colony technique and Nelder–Mead Simplex search technique to optimize the coefficients of Quadrature Mirror Filter (QMF). The performance of QMF can be evaluated in terms of error in the pass-band, stop-band and measure of ripple. A modified objective function is designed in this work, expressed as a weighted sum of errors in the pass-band, stop-band and measure of ripple. A modified objective function is minimized by using the proposed technique. The results obtained from the proposed technique are compared with the previously reported evolutionary optimization techniques based on QMF design. A significant improvement in various performance attributes has been attained compared to earlier reported QMF bank design techniques

Investigating the role of air-sea forcing on the variability of hydrography, circulation, and mixed layer depth in the Arabian Sea and Bay of Bengal

Summary: An effort is made to understand and quantify the influence of near surface zonal and meridional winds, incoming shortwave radiation, and freshwater flux air-sea forcings on the seasonal variability of the hydrography, circulation, and mixed layer depth of the Arabian Sea (AS) and Bay of Bengal (BoB). Sensitivity experiments using an ocean general circulation model are carried out for this purpose in the Indian ocean around 65°–95°E, 5°–22°N during 1998–2014 (17 years). In the absence of near surface wind forcing, the sea surface temperature of the region greatly increases in all the seasons, whereas, in the absence of incoming shortwave radiation forcing, exactly opposite is the case. The sea surface salinity of the AS and BoB decreases in the absence of wind and shortwave radiation forcings, whereas, in the northern BoB it increases in the absence of freshwater flux forcing. The sub-surface changes in the stratification of temperature and salinity are also investigated. The influence of the air-sea forcings on the mixed layer depth of the region is found to be highly seasonally dependent. The effect of air-sea forcings on the seasonal variability of the upper ocean vertical stability is studied using the vertical shear of the horizontal velocity, buoyancy frequency, and energy required for mixing as quantifiers. The near surface wind forcing has highest contribution in changing the surface circulation of the region. Keywords: Arabian Sea and Bay of Bengal, Air-sea forcing, Ocean general circulation model, Hydrography and circulation, Vertical stabilit

Effect of spatial distribution of fibers on elastic properties of unidirectional carbon/carbon composites

Carbon/Carbon composites finds its applications in several high temperature applications in the field of Space, Aviation etc. Designing of components or sub systems with carbon/carbon composites is a challenging task. It requires prediction of elastic properties with a very high accuracy. The prediction can be normally done by analytical, numerical or experimental methods. At the design stage the designers resort to numerical predictions as the experimental methods are not feasible during design stage. Analytical methods are complex and difficult to implement. The designers use numerical methods for prediction of elastic properties using Finite Element Modeling (FEM). The spatial distribution of fibers in matrix has an effect on results of prediction of elastic constants. The generation of random spatial distribution of fibers in representative volume element (RVE) challenging. The present work is aimed at study of effect of spatial distribution of fiber in numerical prediction of elastic properties of unidirectional carbon/carbon composites. MATLAB algorithm is used to generate the spatial distribution of fibers in unidirectional carbon/carbon composites. The RVE elements with various random fiber distributions are modeled using numerical Finite element Model using ABAQUS with EasyPBC plugin. The predicted elastic properties have shown significant variation to uniformly distributed fibers

Minimized Group Delay FIR Low Pass Filter Design Using Modified Differential Search Algorithm

Designing a finite impulse response (FIR) filter with minimal group delay has proven to be a difficult task. Many research studies have focused on reducing pass band and stop band ripples in FIR filter design, often overlooking the optimization of group delay. While some works have considered group delay reduction, their approaches were not optimal. Consequently, the achievement of an optimal design for a filter with a low group delay value still remains a challenge. In this work, a modified differential search optimization algorithm has been used for the purpose of designing a minimal group delay FIR filter. The results obtained have been compared with the classical techniques and they turned out to be promising

Comparative study of two liquid models in the prediction of excess thermodynamic properties of liquid ternary systems

629-636Excess thermodynamic properties i.e. excess volume, excess molar enthalpy, excess molar entropy, excess free energy and excess heat capacity have been evaluated using Prigogine-Flory-Patterson (PFP) and Bertrand-Acree-Bruchfield (BAB) theory for three ternary and its contributory binary liquid systems namely (1) tolune- cyclohexane- carbon tetrachloride and its contributory binaries (toluene+ cyclohexane), (cyclohexane + carbon tetrachloride), (carbon tetrachloride + toluene); (2) benzene – cyclohexane- toluene and its contributory binaries, (benzene + cyclohexane), (cyclohexane + toluene), (toluene + benzene); (3) carbon tetrachloride- cyclohexane – benzene and its contributory binaries, (carbon tetrachloride + cyclohexane), (cyclohexane + benzene) and (benzene + carbon tetrachloride) at 298.15 K over a wide range of compositions. . The results so obtained from these two theories are very much comparable and are in good agreement

Simulation approach for optimization of device structure and thickness of HIT solar cells to achieve similar to 27% efficiency

Optimization of thicknesses of n-type a-Si:H emitter layer, front a-Si:H i-layer and p-type c-Si base wafer as well as optimum heterojunction (HJ) and HJ with intrinsic layer (HIT) solar cells are performed using AFORS-HET simulation software. By optimization, we realized record efficiency of 27.02% in bifacial HIT solar cell at emitter layer, front i-layer and c-Si base wafer thicknesses of 6 nm, 3 nm and 200 mu m, respectively. Interestingly when the thickness of c-Si wafer was reduced to 58 mu m, while keeping the thicknesses of emitter and front i-layers as same as 6 nm and 3 nm, respectively, efficiency in bifacial cell got reduced to 26.45%. All cell structures generated highest efficiency at emitter layer and front i-layer thicknesses of 6 nm and 3 nm, respectively. However, optimum c-Si base wafer thickness was varied according to the following cell structures: simple HJ and HIT cells showed highest efficiency at 300 mu m, HJ with BSF layer cell at 98 mu m, HIT with BSF layer at 58 mu m. It is worth mention that, efficiency in bifacial cell at 58, 98 and 200 mu m was varied nominally. These optimizations may help in producing low cost high efficiency HJ and HIT solar cells technology

A Study of Morbidity and Mortality Profile in General Population of Hosangabad District (Madhya Pradesh)

Objective: The study was conducted to estimate the morbidity and mortality status of general population in the Hoshangabad District. Methodology: This is a community-based cross-sectional (descriptive) study carried out in the Hosangabad district of Madhya Pradesh covering of 509 families comprises of 2985 population. Sample was selected by multistage sampling technique. Result – A total of 2985 respondents, 725 (24%) were from Rural areas and 2260 (76%) from Urban areas. Major cause 640 (21%) of morbidity were due to acute illnesses. In acute illnesses most common was Acute Respiratory Infection241 (8.07%) followed by worm infection 84 (2.81%) and gastroenteritis 58(1.94%). Prevalence of ARI was higher in rural areas but gastroenteritis was higher in urban areas. Most common cause of chronic morbidity among studied population was cataract 42 (1.37%) followed by arthritis 24 (0.80%) and chronic amoebiasis 21 (0.70%). Acute morbidity in urban areas was higher in females (20%) than males (15%). Age specific mortality rate for age group 0-1 and 46-60 & above were significantly higher in rural areas than urban areas. Mortality rate were higher in females (9.7/1000) than males (7.2/1000). Most common cause of mortality in rural areas were diarrhoea, vomiting and dehydration (DVD) 7(38%) followed by cardiac diseases 3(17%) and in contrast urban areas were cardiac diseases 3(43%) followed by 1 (14%) DVD