86 research outputs found
Tearing Out the Income Tax by the (Grass)Roots
Landscapes are increasingly fragmented, and conservation programs have started to look at network approaches for maintaining populations at a larger scale. We present an agent-based model of predator–prey dynamics where the agents (i.e. the individuals of either the predator or prey population) are able to move between different patches in a landscaped network. We then analyze population level and coexistence probability given node-centrality measures that characterize specific patches. We show that both predator and prey species benefit from living in globally well-connected patches (i.e. with high closeness centrality). However, the maximum number of prey species is reached, on average, at lower closeness centrality levels than for predator species. Hence, prey species benefit from constraints imposed on species movement in fragmented landscapes since they can reproduce with a lesser risk of predation, and their need for using anti-predatory strategies decreases.authorCount :
A Preliminary Study on Microbial Contamination of Leafy Vegetables in Sokoto Metropolis, Nigeria
Five leafy vegetables commonly consumed in Sokoto metropolis were evaluated for microbiological quality using standard procedures involving standard plate count (SPC). The vegetables investigated included Lactuaca sativa (Lettuce), Amaranthus hybridus (Spinach), Vernonia amagdalina (Bitter leaf), Brassica oleracea (Cabbage) and Moringa oleifera Lam (Horse radish). Ten fungal species which include Alternaria alternata, Absidia corymbifera, Aspergillus Niger, A. flavus, Cladosporium herbarum, Fusarium oxysporium, Geotrichum candidum, Mucor racemoses, Rhizopus stolonifer and Trichoderma harzianum and four species of bacteria: Bacillus cereus, Escherichia coli, Listeria monocystogens and Staphyllococus aureus were isolated from the leafy vegetables. The total colony counts of fungi ranged from 1.8 x 106 – 6.28 x 105 (cfu/g) of the vegetables while that of bacteria ranged from 1.0 x 106 to 2.94 x 106 cfu/g of the vegetables. The highest counts of microbial organisms were found on A. hybridus while M. oleifera and B. olerarea had the lowest fungal and bacterial counts respectively. There is a need to reduce the levels of microbial contamination on leafy vegetables through appropriate production practices, careful handling by the vendors and appropriate processing with a view to minimize the risk of human exposure to fungal and bacterial pathogens associated with the vegetables
Potentials of Momordica angustisepala fiber in enhancing strengths of normal portland cement concrete
Presence of cracks in concrete affect the integrity. It reduces the life expectancy of concrete structures and is often responsible for collapse of structures, especially in the developing nations. At the root of these cracks is the very low tensile strength of concrete. Various techniques have been suggested for the enhancing the tensile strength, among which is the use of discontinuous micro fibers of various nature. This research investigated the use of Momordica angustisepala (Ma) fiber to enhance concrete strength. Concrete containing coconut fiber was adopted as a control. Slump test, air entrainment test, compression test and split tensile test were carried out on specimens. Results of the research indicate that an optimum Momordica angustisepala fiber contents of 0.25 and 0.5% enhanced respectively the compressive strength by 4.37% and the tensile strength by 10%. The results clearly
show that this renewable material has the potential to enhance the compressive and tensile strengths of concrete
Evaluation of Customer service and Retention; A Comparative Analysis of Telecommunication Service Providers
For a product to receive complete loyalty depends not only
on the quality of the product but also on the satisfaction
derived from such product. All three, loyalty, quality and
satisfaction are significant factors that show how effective the
customer service of an organization is. When customer service is
effective then customer retention/ retention of product is
considered. This study was carried out to investigate on the
effectiveness of customer service in the retention of GSM SIM
packs using a comparative analysis. Data were collected through
the use of questionnaire administered to a determined sample
size of users of the three major GSM service providers. Data were
analyzed and the four hypotheses were tested using correlation
and ANOVA. This study shows that with effective customer
service, customer loyalty and customer satisfaction and
customer retention can be achieved. Though it is observed that
to achieve the afore-mentioned factors, concepts such as
customer expectation, customer-focus and service quality should
be regarded with utmost importance
Developing a Model for Employees’ Intrapreneurial Engagement and Organizational Survival
The survival of any organisation in the midst of economic hardship and competitiveness is becoming a serious concern. One of the strategies organisations can adopt is to tap into the intrapreneurial potentials of their employees. The main objective of this study examines the strategic roles of employees’ intrapreneurial engagement and its implication for organisational survival. A descriptive research method (Structural Equation Model {AMOS 22}) was applied to analyse the two hundred and fifty-nine (259) copies of valid questionnaire completed by the respondents using stratified and simple random sampling techniques. However, the study indicated that fostering employees’ intrapreneurial engagement have positive significant implications on organisational survival. This suggests that employees’ empowerment, involvement, autonomy, relationships and reward system have significant effects on organisational survival. It is therefore recommended that organisations should challenge their employees by providing them with autonomy and the freedom to innovate and carve out spaces for them to take risks and experiment
Development of an intelligent scorpion detection technique using vibration analysis
A possible solution to address the problem of Scorpion stings is the capability of detecting its presence earlier before it stings. This paper presents efforts in Scorpion detection using substrate vibration modelling approach. An eight stage approach has been presented in this work. Using sinusoidal signal, signal representing Scorpion behaviour was firstly sampled and then amplified before transmitting to a nearby receiving module. The received signal undergoes filtering for noise removal before being modelled for coefficients determination. The computed coefficients were then clustered for analysis of behavioural determination. Results obtained in this work show that the proposed technique can be used for Scorpion detection
Scorpion image segmentation system
Death as a result of scorpion sting has been a major public health problem in
developing countries. Despite the high rate of death as a result of scorpion sting, little report
exists in literature of intelligent device and system for automatic detection of scorpion. This
paper proposed a digital image processing approach based on the floresencing characteristics of
Scorpion under Ultra-violet (UV) light for automatic detection and identification of scorpion.
The acquired UV-based images undergo pre-processing to equalize uneven illumination and
colour space channel separation. The extracted channels are then segmented into two nonoverlapping classes. It has been observed that simple thresholding of the green channel of the
acquired RGB UV-based image is sufficient for segmenting Scorpion from other background
components in the acquired image. Two approaches to image segmentation have also been
proposed in this work, namely, the simple average segmentation technique and K-means image
segmentation. The proposed algorithm has been tested on over 40 UV scorpion images
obtained from different part of the world and results obtained show an average accuracy of
97.7% in correctly classifying the pixel into two non-overlapping clusters. The proposed
1 system will eliminate the problem associated with some of the existing manual approaches
presently in use for scorpion detection
Model for simulating scorpion substrate vibration and detection system
Scorpion stings are vital health issues which requires prompt attention to minimize the pain inflicted on victims and avert death. A possible solution in averting the sting is the capability of detecting its presence earlier before it stings. Scorpion like other arthropods have a specific kind of movement pattern called substrate vibration, which generates a specific signal that is used in recognizing and locating mates and preys. This paper aims at developing an intelligent scorpion detection system using vibration frequency detection technique. A six step model for simulating scorpion substrate vibration and detection has been proposed. The surrounding vibrating signal is acquired and passed through a band pass filter. The resulting signal is model using autoregressive modeling technique. Resulting co-efficients are further analyzed for activity detection. The frequency response of scorpion activities for mating behaviou
An adaptive wavelet transformation filtering algorithm for improving road anomaly detection and characterization in vehicular technology
Accelerometers are widely used in modern vehicular technologies to automatically detect and characterize road anomalies such as potholes and bumps. However, measurements from an accelerometer are usually plagued by high noise levels, which typically increase the false alarm and misdetection rates of an anomaly detection system. To address this problem, we have developed in this paper an adaptive threshold estimation technique to filter accelerometer measurements effectively to improve road anomaly detection and characterization in vehicular technologies. Our algorithm decomposes the output signal of an accelerometer into multiple scales using wavelet transformation (WT). Then, it correlates the wavelet coefficients across adjacent scales and classifies them using a newly proposed adaptive threshold technique. Furthermore, our algorithm uses a spatial filter to smoothen further the correlated coefficients before using these coefficients to detect road anomalies. Our algorithm then characterizes the detected road anomalies using two unique features obtained from the filtered wavelet coefficients to differentiate potholes from bumps. The findings from several comparative tests suggest that our algorithm successfully detects and characterizes road anomalies with high levels of accuracy, precision and low false alarm rates as compared to other known methods
Enhanced Clustering Routing Protocol for Power-Efficient Gathering in Wireless Sensor Network
Wireless sensor network (WSN) is a new and fast advancing technology, which is opening up many opportunities in the field of remote sensing and data monitoring. In spite of the numerous applications of WSN, issues related to determining a suitable and accurate radio model that will foster energy conservation in the network limit the performance of WSN routing protocols. A number of radio models have been proposed to address this issue. However, the underlying assumptions and inaccurate configuration of these radio models make them impractical and often lead to mismanagement of scarce energy and computational resources. This paper addresses this problem by proposing an enhanced radio model that adapts to the frequent changes in the location of the sensor nodes and is robust enough to report reliable data to the base station despite fluctuations due to interference. The impact of incorporating stepwise energy level and specialized data transmission schemes in the proposed radio model is also investigated in this paper. The performance of the proposed radio model is evaluated using OMNET++ and MATLAB and the results obtained is benchmarked against PEGASIS. It is shown by simulation that the novel LEACH-IMP performs better with respect to energy consumption, number of links faults, number of packets received, signal attenuation, and network lifetime
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