6,494 research outputs found
Sampling and Recovery of Pulse Streams
Compressive Sensing (CS) is a new technique for the efficient acquisition of
signals, images, and other data that have a sparse representation in some
basis, frame, or dictionary. By sparse we mean that the N-dimensional basis
representation has just K<<N significant coefficients; in this case, the CS
theory maintains that just M = K log N random linear signal measurements will
both preserve all of the signal information and enable robust signal
reconstruction in polynomial time. In this paper, we extend the CS theory to
pulse stream data, which correspond to S-sparse signals/images that are
convolved with an unknown F-sparse pulse shape. Ignoring their convolutional
structure, a pulse stream signal is K=SF sparse. Such signals figure
prominently in a number of applications, from neuroscience to astronomy. Our
specific contributions are threefold. First, we propose a pulse stream signal
model and show that it is equivalent to an infinite union of subspaces. Second,
we derive a lower bound on the number of measurements M required to preserve
the essential information present in pulse streams. The bound is linear in the
total number of degrees of freedom S + F, which is significantly smaller than
the naive bound based on the total signal sparsity K=SF. Third, we develop an
efficient signal recovery algorithm that infers both the shape of the impulse
response as well as the locations and amplitudes of the pulses. The algorithm
alternatively estimates the pulse locations and the pulse shape in a manner
reminiscent of classical deconvolution algorithms. Numerical experiments on
synthetic and real data demonstrate the advantages of our approach over
standard CS
Modular AC coupled hybrid power systems for the emerging GHG mitigation products market
Bioenergy systems particularly waste to energy (WTE) systems are increasingly gaining prominence. Market for modular hybrid energy systems (HES) combining renewable energy sources including WTEs is potentially large. Novel configuration of AC coupling for HES is discussed. Emerging opportunities for market development of hybrid energy systems under green house gas mitigation initiatives particularly Kyoto flexibility mechanisms is analysed
Empowerment of Women for Improved Quality of Life
Technological developments and information technologies are rapidly changing the economy and lifestyle However women in many developing countries are still deprived of their rights and needs Over the time women in India have faced many problems of inequality and deprivation which have also been a cause of illiteracy and poverty Focused attempt to empower women through sensitization of the community reduction of hardship improved health care development of various skills and support for promoting several income generation activities along with necessary policy support can improve the status of women within 3-5 years even in the backward regions While saving time on their routine household duties and improving the health status of themselves as well as that of their children they have been happy to take up the additional workload for food security and income generation The initial preferences of rural women for income generation were agriculture and livestock husbandry over non-farm activities because of inherent skills and high demand for the produc
Hydrothermal Ethanol Flames in Co-Flow Jets
Results on the autoignition and stabilization of ethanol hydrothermal flames in a Supercritical Water Oxidation (SCWO) reactor operating at constant pressure are reported. The flames are observed as luminous reaction zones occurring in supercritical water; i.e., water at conditions above its critical point (approximately 22 MPa and 374 C). A co-flow injector is used to inject fuel (inner flow), comprising an aqueous solution ranging from 20%-v to 50%-v ethanol, and air (annular flow) into a reactor filled with supercritical water at approximately 24.3 MPa and 425 C. Results show hydrothermal flames are autoignited and form diffusion flames which exhibit laminar and/or turbulent features depending upon flow conditions. Two orthogonal camera views are used; one providing a backlit shadowgraphic image of the co-flow jet and the other providing color images of the flame. In addition, spectroscopic measurements of flame emissions in the UV and visible spectrum are discussed
A randomized comparative clinical study of Manjistha Ghrita (Rubia Cordifolia Linn.) and Go-Ghrita in the management of Kikkisa (Striae Gravidarum)
Skin ailments are the third most common disease in developing countries and in modern society it is a subject of sociomedical importance. One such ailment associated with pregnancy is Kikkisa (Striae gravidarum). Kikkisa (Striae gravidarum) is a Garbhini Vyadhi which occurs mostly in Sapta Masa of Garbhini Kala (7th month of pregnancy). It is a condition where growing foetus enlarges Garbhashaya which displaces Doshas Vata, Pitta and Kapha upwards, reaches Uras and produces Daha causing Kandu on abdomen, breasts and thighs. Striae gravidarum are seen in 50-90% of pregnant women due to many physiological, metabolic and hormonal changes along with increased stress on connective tissue will lead to breakage of fibers. Manjistha (Rubia cordifolia Linn.) is considered as Raktashodaka and Kushtanuta. Considering the risk factors in pregnancy the current study has been taken up under external application of Manjistha in the form of Ghrita over internal usage of Kwatha as mentioned in authentic text. Keeping this in mind a comparative study was conducted to analyze the effect of Manjistha Ghrita and Go-Ghrita on Striae gravidarum.30 subjects after considering the inclusion and exclusion criteria were taken up for the study. Patient’s general and physical examinations were done. On day 0, through inspection if Striae were observed then Manjistha Ghrita and Go-Ghrita were given in alternative manner. Patients were asked to come for follow up on Day 15. The study period was 30 days and on Day 30, patients were examined to check for any changes in Striae. The obtained data were analyzed statistically using Paired T test, UnPaired T test, Wilcoxon test, Mann Witney test, by using SPSS Software. Usage of Manjistha Ghrita gave considerably good results statistically when compared to application of Go-Ghrita as it only helped in reducing the symptoms till the subjects used the medication and there was recurrence of symptoms later
Robust Hybrid Precoding for Interference Exploitation in Massive Mimo Systems
In this paper, we consider a multiuser massive MIMO system with hybrid analog-digital precoding architecture. The phase shifters in the hybrid precoding architecture are assumed to be imperfect, where the true values of both phase and magnitude of the phase shifters are different from their nominal values. For a given analog precoding matrix, we develop an iterative algorithm to compute robust digital precoders based on the interference exploitation approach to eliminate any potential symbol errors due to the phase shifter impairments. Numerical experiments demonstrate the performance of the proposed algorithm and show its advantage over a conventional robust precoding technique
Superior Supercapacitors based on Biowaste Materials
Carbon nano spheres derived from Allium cepa were synthesized at different temperatures in a one-step pyrolysis process for supercapacitor electrodes. Obtained carbon nano spheres were analyzed using SEM, FTIR, BET and XRD. The nano materials were fabricated into conducting electrodes for cyclic voltammetry, constant current charge-discharge and electrochemical impedance spectroscopy studies. All the studies were done in 3.0 M KOH electrolyte. Specific capacitance from charge discharge experiments were found to be 132.03 F/g and 149.49 F/g for nano materials synthesized at 500ºC and 600ºC respectively. Obtained values suggest a way forward in producing a green electrode for commercial applications
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