356 research outputs found

    Climate Change,Urban Degreening and Flooding in Nigerian Cities:Reducing Vulnerability Through Polycentric Planning and Urban Greeenery Strategy(PPUGS)

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    This paper uses the Institutional Analysis and Development (IAD) framework to analyse the missing links in attempts to address the problems of flooding in Nigerian cities. Previous flooding and the recent ones have been attributed to heavy downpour, blockage of water channels and drainages, indiscriminate dumping of refuse and building of houses along channels. Areas that are neglected but pertinent to flood mitigation include: (1) degreening activities that remove green cover; (2) paving of open spaces with asphalt and concrete that accentuate storm water volume as percolation is reduced; and (3) unpaved surfaces that generate debris and silts that cause siltation and sedimentation of Atlantic Ocean and Lagoon with the consequence of rising sea level and coastal flooding. The paper reports the findings of longitudinal studies on causative factors of urban flooding. The studies commenced in Ile-Ife and Ibadan in 1997, conducted in Lagos in 1998-2000 and 2011 and in Ibadan in 2011 and 2012. The paper identified gaps between and among the stakeholders in environmentalism and ecosystemic balance at state and local levels. Indications from Ile-Ife, Lagos and Ibadan show that the three cities are experiencing degreening activities. For example, in Ile-Ife and Lagos, the green areas account for the least proportions, 24.1% and 27% of open spaces around buildings respectively, while 75.9% and 73.0% of the available open spaces are either paved or unpaved with the problem of heat radiation that demands additional energy for operating artificial cooling system and consequently increased global warming. In addition, degreening activities cause flooding. As more and more land is urbanised, and trees and grasses are replaced by asphalt and concrete, rainwater has less chance to be absorbed. Thus, storm water rushes down the streets while areas that were never flooded are now routinely under water. Other studies in Lagos show that: (i) there is an increase in the rate of sedimentation and sea level rise (ii) rainstorms in the city have become more intense and urban flooding will be more severe. Floods have devastated many parts of Lagos and Ibadan leading to loss of several lives and property and the displacement of several people. Statistics confirms that between 2011 and 2012, more than 150 billion naira (about $1 billion) was lost in Lagos, while 2,105 buildings were flooded in Ibadan with property damaged estimated in billions of Naira. As a result, the Lagos and Oyo States‟ Governments spent several millions of Naira on relief to the victims. This paper raises some fundamental questions on the roles of stakeholders (scholars, public officials, practitioners, professionals and citizens) within the built environment in designing strategies at mitigating urban flooding. This paper considered it imperative for the adoption of pragmatic and problem-solving strategies that can help in mitigating flooding in Lagos and Ibadan. Consequently, the paper designs an African Polycentric Urban Greenery Model (APUGM) that can be applied to addressing the challenges of flooding in the two cities. The paper emphasizes, among other considerations, the use of traducture in reaching the grassroots for solution to the recurrent challenges of flooding. The paper also designs strategies that Lagos and Oyo states‟ governments could adopt for the depopulation of the two cities – Lagos and Ibadan respectively through de-urbanisation, de-migration and re-migration

    Automation and Easy Accessibility of Medical Services in Nigeria (ICT and Medicine)

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    The Internet and Information Communication Technology (ICT) infrastructures are transforming the future of healthcare management. The cost of healthcare delivery systems, products, and services continue to rise unabated, especially in Nigeria – a developing nation that needs technology transfer. Knowledge is one of the crucial resource and precondition to strengthen health systems. Access to knowledge has large impact on health system management and up to date patient care. The great challenges lie in the optimal utilization of rapid spreading information and communication systems (ICTs) and innovative applications such as telemedicine and e-health. Telemedicine is the practice of diagnosis, consultation and treatment between physicians and distant patients through the use of telephone and computers that transmit data for remote television viewing and treatment from a distance. The concept of telemedicine is a dream to come through in Nigeria, but if developed and taken right to the community hospitals, it can prove to be very beneficial, especially in giving timely treatment to wounded soldiers or plague patients, as a majority of the specialists prefer being stationed at big urban centers, with the rural populace being the real sufferer. Modern health information systems are a requisite for efficient and equitable resource allocation. Moreover, the Internet has pushed networking technology into the mainstream and it is without doubt the most important network, both in terms of technology advances and social impact, in the world. However, telemedicine provides a cost effective means of technological transfer both machine and expatriate advice through ICT connectivity.

    Improving Prioritized Handover Performance for Mobile WiMAX by Dynamic Guard Channel Allocation and RSS Quality Factor

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    In cellular communication, guard channel has been used to provide priority to ongoing call traffic crossing cell boundaries in handover process but the major concern is that most guard channel allocation scheme are fixed channels. System congestion problems arising from traffic pattern in the real world is another major concern relating to fixed allocation of guard channels let alone the huge traffic that will emanate from user mobility in the envisaged converged traffic of 4G networks. Hence, dynamic guard channel (DGC) allocation based on traffic intensity or channel utilization of each traffic type was used in this research and it reduced the new call blocking probability better than the fixed prioritized guard channel (PGC) and non-prioritized channel allocation scheme. Its performance in terms of call dropping probability reduction is comparable with the PGC and slightly better off at poor signal condition. It was revealed that DGC averaged QoS better than the existing channel assignment schemes. An investigation into the RSS quality factor (QF) proposed also, showed that at high quality RSS the blocking and dropping probability of the traffic were reduced for the Mobile WiMAX wireless technology network with mobile assisted handover

    Performance Comparison of Dynamic Guard Channel Assignment with Buffered Prioritized Scheme for Mobile WiMAX Network

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    Abstract—Priority is usually given to handover traffic in mobile communication but doing so has the tendency of increasing call blocking probability. It was said previously that non-prioritized call traffic channel assignment scheme reduces call blocking probability more than other basic channel assignment schemes at high handover traffic intensities. A comparison of channel assignment schemes by analysis and MATLAB simulation in this research has shown that dynamic guard channel assignment scheme based on channel utilization minimizes call blocking probability better than non-prioritized, prioritized guard channel and prioritized guard channel with queue/buffer. The wireless technology used was Mobile WiMAX with mobile assisted handover (MAHO) and the queueing policy employed was M/M/C/Q with FCFS service discipline

    A Comparative Simulation Study of IP, MPLS, MPLS-TE for Latency and Packet Loss Reduction over a WAN

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    The need for improved network performance towards providing reliable services in the face of growing demand on enterprise network and internet service across all sectors of the economy has become very paramount. Latency and packet loss as quality of service (QoS) metrics are issues of concern since different multimedia applications, voice and data packets have to be delivered to end systems over long distances. This study investigated the technology behind the delivery of the packets by comparing the performance of each of IP, MPLS and MPLS-TE on the same congested WAN design. The results showed that MPLS-TE had the least latency and barely any packet los

    Performance Evaluation of Dynamic Guard Channels Assignment with Queue and Prioritized Schemes

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    It has been said that dynamic guard channel (DGC) assignment scheme based on traffic intensities averages QoS and performs better than the prioritized guard channel assignment scheme with queue (QPGC) during traffic congestion. This work has extended the investigation to DGC with queue (QDGC) and carried out its comparison with other call traffic channel assignment schemes. Mathematical analysis of the models was done using Markov chain and simulation was carried out in MATLAB. When traffic arrival rates were symmetric, the QPGC had the lower call blocking probability than the QDGC but became the same when the system was congested. However, the performance of the two queuing schemes was the same when handover call traffic was more than new calls traffic
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