2,761 research outputs found
M-GEAR: Gateway-Based Energy-Aware Multi-Hop Routing Protocol for WSNs
In this research work, we advise gateway based energy-efficient routing
protocol (M-GEAR) for Wireless Sensor Networks (WSNs). We divide the sensor
nodes into four logical regions on the basis of their location in the sensing
field. We install Base Station (BS) out of the sensing area and a gateway node
at the centre of the sensing area. If the distance of a sensor node from BS or
gateway is less than predefined distance threshold, the node uses direct
communication. We divide the rest of nodes into two equal regions whose
distance is beyond the threshold distance. We select cluster heads (CHs)in each
region which are independent of the other region. These CHs are selected on the
basis of a probability. We compare performance of our protocol with LEACH (Low
Energy Adaptive Clustering Hierarchy). Performance analysis and compared
statistic results show that our proposed protocol perform well in terms of
energy consumption and network lifetime.Comment: IEEE 8th International Conference on Broadband and Wireless
Computing, Communication and Applications (BWCCA'13), Compiegne, Franc
One-minute rain rate statistics prediction using Ito-Hosoya model in Malaysia
This paper investigates one-minute rain rate in Kuala Lumpur, Malaysia predicted based on Ito-Hosoya model. The model is categorized into meteorological based model as it receives as input local meteorological parameter. The best part about this model is it does not requires measured rain rate data to be converted into one-minute, instead it depends on long-term meteorological parameter values which widely available from various sources. In this paper, the local meteorological parameters are extracted from TRMM database which are average accumulation rainfall (from TMPA 3B43) and thunderstorm ratio (from TRMM PR 3A25 and TMI 3A12). The result shows that this model could be promising for use in Malaysia region as it produces better performance compared to the ITU-R model
Comparison of normal incident sound absorption coefficient of direct piercing carved wood panel for circular, geometry and floral design
Direct Piercing Carved Wood Panel (DPCWP) is among the famous Malay wood carving art in the Malay culture. It is the best example of Malay people’s creativity and masterpiece. In this paper, the comparison of normal incidence sound absorption coefficient, αn (SAC) for three major types of design for the DPCWP is discussed. The simplest form of DPCWP, the circular type, then the geometry and floral types were investigated based on simulation and measurement works using sound intensity method to determine the normal incidence SAC, for 30% and 40% perforation ratios. The simulation work was carried out by using BEASY Acoustic software based on Boundary Element Method (BEM). From the results, there is an identical trend for DPCWP with geometry and floral design from 250 Hz to 4 kHz. At high frequencies (1 kHz to 4 kHz), both design show the tendency of decrement, suggesting that the complexity of the design does affect the average SAC value. However, for circular design, SAC is higher than other design at 1 kHz and shows a similar trend with other design at 2 kHz and 4 kHz for both simulation and measurement result
Mangrove spatial structure in a monospecific stands of the black mangrove <i>Avicennia germinans</i> (L.) Stearn in the Cameroon estuary
Mangrove forest structure organisation in a monospecific stand of the black mangrove <i>Avicennia germinans</i> (L.) Stearn in the Cameroon estuary
One of the major components of forest stand structure is the spatial arrangement of tree positions and the distribution pattern of species. Avicennia (Acanthaceae) is considered an important colonizer of new areas. This genus comprises about eight species of which only one, namely the Black mangrove Avicennia germinans, occurs in Cameroon mangrove forests. Through extension its complex of pneumatophores this species causes solidification of the soft substrate, hence facilitating the stabilization of coastal zones. In spite of this ecological importance, little is known about the patterning of A. germinans forest stands. In this contribution, we characterized the stand structure of this species in the Wouri Estuary (Cameroon). We located two sites in the landward margin and one on the seaward edge. There, we established 20 plots of 40mĂ—40m along belt transects, and subdivided each plot into 16 subplots of 10mĂ—10m. We measured the diameter, height and spatial coordinates of all A. germinans stems and finally determined the type of spatial arrangement of trees based on the number of stems counted in each subplot. Our results showed that the mean tree diameter, basal area and height were considerably higher on the seaward edge than in the landward margin, and with few exceptions, the spatial arrangement of A. germinans trees was commonly clumped. These different patterns were consistent with the map resulting from the recorded spatial coordinates. On one hand, the clumped spatial arrangement of trees could be due to the fact that seedlings of A. germinans are often dispersed over greater distances by tidal action (seaward edge), while on the other hand, the same pattern might be attributed to their capabilities of settling close to the senescent tree in less flooded areas (landward margin). Moreover, when seedlings are trapped by the pneumatophores, this can lead to a random distribution sometimes recorded in the two different locations. In addition to our findings, it is important to develop a more complete characterization of the stand structure of A. germinans. We believe this objective can be achieved by analyzing endogenic organisation processes that occur within the growing environment of this species
Exploring the Roles of Social Participation in Mobile Social Media Learning: A Social Network Analysis
Social media is increasingly becoming an essential platform for social connectivity in our daily lives. The availability of mobile technology has further fueled its importance – making it a ubiquitous tool for social interaction. However, limited studies have been conducted to investigate roles of social participation in this field. Thus, the study investigates roles of social participation in mobile social media learning using the “ladder of participation and mastering.” Participants were students taking an educational technology course in a local university. The study was conducted in a four-month period. Data was collected from discussions while learning among the students a social media platform, Facebook groups, on mobile devices. The data was analyzed using a social network analysis tool, NodeXL. Data was analyzed based on egocentric networks, betweeness centrality, and closeness centrality. The findings revealed that there are four roles of social participation in mobile social media, which are: (i) lurkers; (ii) gradually mastering members/passive members; (iii) recognized members; and (iv) coaches. The findings also indicated that over the course of four months, learners can inter-change roles of social participation – becoming more central or less central in learning discussions. As a result, a roles of social participation continuum for mobile social media learning is proposed. Future research could be conducted in other fields to investigate whether the continuum produced could be used to understand the relationship between mobile social media learning and social participation roles
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