1,104 research outputs found
Significance of Weighted-Type Fractional Fourier Transform in FIR Filters
The desired frequency response of a filter is periodic in frequency and can be expanded in Fourier series. One possible way of obtaining FIR filter is to truncate the infinite Fourier series. But abrupt truncation of the Fourier series results in oscillation in the pass band and stop band. These oscillations are due to slow convergence of the Fourier series by the Gibb's phenomenon. To reduce these oscillations the Fourier coefficients of the filter are modified by multiplying the infinite impulse response with a finite weighing sequence called a window. The Fourier transform (FT) of a window consists of a central lobe and side lobes. The central lobe contains most of the energy of the window. To get an FIR filter, the desired impulse response and window function are multiplied, which results to give finite length non-causal sequence. Since Fractional Fourier Transform (FrFT) is generalization of FT. Here an attempt is to implement filters using window by using Weighted Type Fractional Fourier Transform (WFrFt), differentiator and integrator using weighted FrFt is also present
Climate change impact on coastal fisheries and aquaculture in the SAARC
Observations in fisheries sciences related to climate change foresee a future
with intensified climate change as a consequence of increased greenhouse gases
(GHGs) in the atmosphere because of human activities. The increase in GHGs
has resulted in warming of climate systems or global warming. In last 100 years,
ending in 2005, the average global air temperature near the earth’s surface has
been estimated to increase at the rate of 0.74 ± 0.18°C (1.33 ± 0.32°F) (IPCC,
2007). In the latest IPCC report (IPCC, 2014), climate model projections
indicated that the global surface temperature during the 21st century is likely to
rise a further 0.3 to 1.7°C (0.5 to 3.1°F) for their lowest emissions scenario and
2.6 to 4.8°C (4.7 to 8.6°F) for the highest emissions scenario. In the past, 15 of
the 16 warmest years have occurred since 2001 and rank among the 15 warmest
years in the instrumental record of global surface temperature since 1850.
Climate change and associated warming is increasingly being felt in many parts
of the globe including India. Climate change is predicted to lead to adverse,
irreversible impacts on the earth and the ecosystem as a whole. Although it is
difficult to connect specific weather events to climate change, increases in
global temperature has been predicted to cause broader changes, including
glacial retreat, arctic shrinkage and worldwide sea level rise (Mohanty et al.,
2010).The Chaliyar river is one of the west flowing rivers of Western Ghats. It has many tributaries such as Karimpuzha. Punnappuzha, Kuruvanpuzha, Tiruanchipuzha, Cherupuzha. etc. with a catchment area of 1535 sq. km. The total discharge of the river is 7775 Mm3, The river which was in a pristine condition before 4 to 5 decades has become highly degraded in the lower stretches by the effluents of Gwalior Rayons and in the upper stretches by various anthropogenic factors like deforestation, high siltation, dynamite fishing and use of copper sulphate for fishing. During the summer months, the water in the river is very low due to high run off during the wet months
Evolution of the fishtail-effect in pure and Ag-doped MG-YBCO
We report on magnetic measurements carried out in a textured
YBaCuO and YBa(CuAg)O (at
0.02) crystals. The so-called fishtail-effect (FE) or second
magnetization peak has been observed in a wide temperature range
0.4~~0.8 for . The origin of the FE arises for
the competition between surface barrier and bulk pinning. This is confirmed in
a non-monotonically behavior of the relaxation rate . The value
for Ag-doped crystals is larger than for the pure one due to the presence of
additional pinning centers, above all on silver atoms.Comment: 6 pages, 6 figure
Analysis on improving operational efficiency of construction project site
Operational efficiency directly reflects the profitability of a project. It is for benefit of a construction site. The current research paper focus on high operational efficiency by reducing waste, better layout planning, sound administration, business practices an, review of existing facilities etc. To improve the operational efficiency will enhance the profit by adding the value to the project in the form of cost reduction in internal transportation, utilization of existing facilities effectively. The study adopted the Computerized Relative Allocation of Facilities Techniques (CRAFT) and computerized relationship planning (CORELAP) algorithm to analyze the operational efficiency
Anomalous diffusion modifies solar neutrino fluxes
Density and temperature conditions in the solar core suggest that the
microscopic diffusion of electrons and ions could be nonstandard:
Diffusion and friction coefficients are energy dependent, collisions are not
two-body processes and retain memory beyond the single scattering event.
A direct consequence of nonstandard diffusion is that the equilibrium energy
distribution of particles departs from the Maxwellian one (tails goes to zero
more slowly or faster than exponentially) modifying the reaction rates.
This effect is qualitatively different from temperature and/or composition
modification: Small changes in the number of particles in the distribution
tails can strongly modify the rates without affecting bulk properties, such as
the sound speed or hydrostatic equilibrium, which depend on the mean values
from the distribution.
This mechanism can considerably increase the range of predictions for the
neutrino fluxes allowed by the current experimental values (cross sections and
solar properties) and can be used to reduce the discrepancy between these
predictions and the solar neutrino experiments.Comment: 16 pages, ReVTeX, no figures. Text partially revised (24 april 1998
Significance of Weighted-Type Fractional Fourier Transform in FIR Filters
The desired frequency response of a filter is periodic in frequency and can be expanded in Fourier series. One possible way of obtaining FIR filter is to truncate the infinite Fourier series. But abrupt truncation of the Fourier series results in oscillation in the pass band and stop band. These oscillations are due to slow convergence of the Fourier series by the Gibb’s phenomenon. To reduce these oscillations the Fourier coefficients of the filter are modified by multiplying the infinite impulse response with a finite weighing sequence called a window. The Fourier transform (FT) of a window consists of a central lobe and side lobes. The central lobe contains most of the energy of the window. To get an FIR filter, the desired impulse response and window function are multiplied, which results to give finite length non-causal sequence. Since Fractional Fourier Transform (FrFT) is generalization of FT. Here an attempt is to implement filters using window by using Weighted Type Fractional Fourier Transform (WFrFt), differentiator and integrator using weighted FrFt is also present
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