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