737 research outputs found
Iterative Time-Varying Filter Algorithm Based on Discrete Linear Chirp Transform
Denoising of broadband non--stationary signals is a challenging problem in
communication systems. In this paper, we introduce a time-varying filter
algorithm based on the discrete linear chirp transform (DLCT), which provides
local signal decomposition in terms of linear chirps. The method relies on the
ability of the DLCT for providing a sparse representation to a wide class of
broadband signals. The performance of the proposed algorithm is compared with
the discrete fractional Fourier transform (DFrFT) filtering algorithm.
Simulation results show that the DLCT algorithm provides better performance
than the DFrFT algorithm and consequently achieves high quality filtering.Comment: 6 pages, conference pape
Distribution of heavy metals in sediments of Igbede, Ojo and Ojora rivers of Lagos, Nigeria
The distribution of some heavy metals,
namely Cd, Pb, Zn, Fe, Cu, Cr and Mn in epipellic
sediments of Igbede, Ojo and Ojora rivers of Lagos
was studied weekly in the early summer (November)
of 2003. The levels of selected trace metals were determined
using Atomic Absorption Spectrophotometer
(UNICAM 969 AAS SOLAR). Trends in heavy metal
burdens in the sediments revealed weekly variations in
all the rivers assessed. Statistical analyses also showed
different mean levels of trace metals in the aquatic environments,
the distribution of which followed the sequence
Fe > Zn > Mn > Pb > Cu > Cr > Cd, Fe
> Zn > Cu > Mn > Pb > Cr > Cd and Fe > Zn >
Mn > Cu > Cr > Pb > Cd in Igbede, Ojo and Ojora
rivers respectively. Fe recorded the highest concentration
levels (1,582.95 ± 96.57 μg/g–1,910.34 ± 723.19
μg/g) in all the sediments investigated while the Cd
levels (0.06 ± 0.10 μg/g–0.47 ± 0.36 μg/g) were the
lowest. Expectedly, trace metal concentrations in fine
grain muddy sediments of the Igbede and Ojo coastline
were much higher than those of Ojora which consist
of coarse and sandy deposits covering the near shore
area. Generally, the results obtained fell within toler-able limits stipulated by World Health Organization
(WHO)
THE EFFECT OF STEREOTYPE ON COGNITIVE PERFORMANCE: AN EXPERIMENTAL STUDY OF FEMALE COGNITIVE PERFORMANCE
This study investigated the effect stereotypes have on cognitive performance. A between-subjects experimental design was utilized in the study. Forty participants from the senior secondary two (SS2) of Chapel Secondary School Ilorin took part in the study, and their cognitive performance in the light of exposure to a stereotype was
measured. Four hypotheses were tested. Using the t-test for
independent samples, the findings of the experiment showed that males performed better than females on a mathematics test when exposed to stereotype (t=2.688, df=l8, p<O.OS). The study also found that males who were exposed to stereotype performed better than males who were not exposed to stereotype (t=2.998, df=l8, p< 0.05).
However, there was no significant difference in the performance of females who were exposed to stereotype and those who were not (t=2.740, df=l8, p>O.OS). Stereotypes have been identified to affect the way people see things and the way they interpret certain behaviours of
other individuals or groups. Therefore understanding the nature of stereotypes, prejudice, and discrimination is the first step in combating these practices
Optimal Structural Results for Assemble-to-Order Generalized M-Systmes
Cataloged from PDF version of article.We consider an assemble-to-order generalized M-system with multiple components and multiple products,
batch ordering of components, random lead times, and lost sales. We model the system as an in nite-horizon
Markov decision process and seek an optimal control policy, which speci es when a batch of components
should be produced and whether an arriving demand for each product should be satis ed. To facilitate
our analysis, we introduce new functional characterizations for convexity and submodularity with respect to
certain non-unitary directions. These help us characterize optimal inventory replenishment and allocation
policies under a mild condition on component batch sizes via a new type of policy: lattice-dependent base-stock
and lattice-dependent rationing
Spectrum-Aware and Energy-Adaptive Reliable Transport for Internet of Sensing Things
© 1967-2012 IEEE. Wireless sensors equipped with cognitive radio, i.e., cognitive radio sensor networks (CRSN), can access the spectrum in an opportunistic manner and coexist with licensed users to mitigate the crowded spectrum problem and provide ubiquitous remote event monitoring and tracking for cyber-physical systems. In this paper, a novel transport layer protocol for CRSN, spectrum-aware energy-adaptive reliable transport protocol is presented to enable energy-adaptive collaborative event sensing in spectrum-scarce cyber-physical systems. To the best of our knowledge, this is the first attempt to specifically devise a reliable event transport scheme for CRSN
Mapping of Thermo-Fluids Laboratory Experiments Into Web-Based Experiments
A methodology is being developed for transforming physical experiments from the undergraduate thermo-fluids laboratory into a web-based virtual experiments. Important characteristics of physical experiments are identified in order to preserve them in physical to virtual domain mapping. Several commercially available software are employed to incorporate in the web-based experiments characteristics such as recreation of physical phenomenon in the virtual domain, measurement of physical quantities on a computer screen, assembly of virtual probes and coupling of the virtual experiment with a data acquisition software. A virtual reality software has been incorporated to enable web-based students to navigate through the virtual laboratory, and perform the virtual experiment on-line. The web-based virtual experiment module has the potential of becoming a building block for virtual laboratories for web-based undergraduate engineering programs
Controlled Information Transfer Through An In Vivo Nervous System.
The nervous system holds a central position among the major in-body networks. It comprises of cells known as neurons that are responsible to carry messages between different parts of the body and make decisions based on those messages. In this work, further to the extensive theoretical studies, we demonstrate the first controlled information transfer through an in vivo nervous system by modulating digital data from macro-scale devices onto the nervous system of common earthworms and conducting successful transmissions. The results and analysis of our experiments provide a method to model networks of neurons, calculate the channel propagation delay, create their simulation models, indicate optimum parameters such as frequency, amplitude and modulation schemes for such networks, and identify average nerve spikes per input pulse as the nervous information coding scheme. Future studies on neuron characterization and artificial neurons may benefit from the results of our work
Level Of Some Heavy Metals In River Ogun, Nigeria
The levels of some heavy metals in River Ogun were investigated using Atomic Absorption Spectrophotometer ''
(AAS). Metals analyzed were Cd, Co, Cu, Cr. Fe, Mn, Pb and Zn; in order to know how healthy the medium for
human consumption is. The results showed that the mean concentration of these heavy metals were 1.14 mg [1
cadmium, 1.11 mg [ 1 cobalt, 0. 32 mg [1 for copper, 0. 77 mg [ 1 chromium, 20.54 mg [ 1 iron, 2. 45 mg [1
manganese, 3.53 mg [1 lead and 1.61 mg [ 1 zinc. These results were compared with the WHO standard guidelines;
and discharge of untreated industrial wastes and occupational wastes from dyeing activities, into the river
responsible the level of pollution of River Ogun
Petroleum hydrocarbons and limiting nutrients in Macura reptantia, Procambarus clarkii and benthic sediment from Qua Iboe Estuary, Nigeria
The levels of total petroleum hydrocarbons in two commonly consumed benthopelagic shellfishes, Macura reptantia and Procambarus clarkii, harvested from benthic sediment of Qua Iboe Estuary were determined using a gas chromatography with flame-ionization detector. Seventy-two (72) samples each of benthic sediment and the shellfishes were collected monthly between June 2003 and February 2004 covering the peak periods of the wet and dry seasons. Concentrations of hydrocarbons were highly variable and ranged between 5.00 and 232.00 μg/g dry weight of benthic sediment, 3.05 and 11.30 μg/g dry weight of M. reptantia, 1.62 and 9.00 μg/g dry weight of P. clarkii. Pearson’s correlation analysis of total hydrocarbon concentrations in subtidal sediments with levels in the fauna species yielded positive significant (P < 0.05) correlations in M. reptantia (r = 0.737) and P. clarkii (r = 0.924). This is indicative of a long term and chronic accumulation of hydrocarbons in the estuarine ecosystem, reflecting the potential for exposure of the resident biota and the risk to human health
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