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Goodness-of-Fit Test for Volume Equations of Three Timber Species in South East Cameroon

Journal of Environmental Science and Engineering(B) 2012年第5期1卷 600-605页

作者： Eric Ngbanye Ntabe John Adebayo Akande lawrence adetunji kehinde Department of Forestry Faculty of Agronomy & Agricultural Sciences University of Dschang Dschang 222 Cameroon Department of Crop Production Soil & Environmental Management BOWEN University lwo Osun Osun State Nigeria Department of Agricultural Economics Osun State University Osogbo Osun Osun State Nigeria

A study on the validity of volume equations currently used for three timber species, Entandrophragma cylindricum, Erythrophleum ivorensis and Pericopsis elata （Sapelli, Tali and Assamela respectively） in south east Cameroon, was conducted between the months of July and September, 2007 to evaluate their suitability for the site. Twenty-two percent sampling intensity was conducted within annual allowable cuts and diameter readings taken on standing trees with the aid of a wide band Relascope. A non linear regression equation model was employed to compute volume equations and the student＇s t-test for the analysis of the existing models. Based on individual tree volumes within stands, new equations for the three species were constructed. A comparison was made between the new equations and those that were being used at the site. Results indicated a total standing volume of 0.007 m3/ha obtained for the three species （Sapelli 0.003 m3/ha, Tali 0.002 m3/ha and Assamela 0.002 m3/ha）. Two new volume equation models [B] and [C] were retained for their goodness-of-fit with [B] for Assamela and [C] for Sapelli and Tali. Results also showed that a total volume of 0.005 m3/ha was underestimated for the three species （Sapelli 0.002 m3/ha, Tali 0.001 m3/ha and Assamela 0.002 m3/ha） when existing volume equations were applied. It is imperative to construct new volume equations that are compatible with the ecological characteristics of the site using representative samples. Setting-up appropriate methods for their validation shall also serve as checks to future management errors.

关键词： Volume equations misapplication timber species Cameroon.

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Agricultural Sector and HIV/AIDS Pandemic in Africa: The Economic Retrogression Model

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Agricultural Sciences 2016年第4期7卷 206-224页

作者： Temidayo Gabriel Apata Moshood Olatunde Oladapo adetunji lawrence kehinde Olasimbo Motunrayo Apata Timothy Olusola Agboola Department of Agricultural Economics & Extension Federal University Oye-Ekiti Oye-Ekiti Nigeria Department of Agricultural Economics & Extension Osun State University Ejigbo Campus Ejigbo Nigeria Department of Agricultural Economics & Extension Ekiti State University Ado Ekiti Nigeria

Objective: Agricultural activities in most African countries demand human labour, the supply of labour to agriculture may be threatened if humans could no longer farm because of HIV/AIDS pandemic. Past studies have identified the alarming situation and challenges the spread of HIV/AIDS endemic poses to human existence and agricultural growth. Examining these interactions, and their direction, is useful for informing policy directives. Therefore, the general objective of this study is to examine interactions between HIV/AIDS pandemic and agricultural growth in Africa using a model of retrogression. Methods: Twenty countries in Africa identified as HIV/AIDS ravaged countries were taken as the areas of study. These countries are spread over four zones of the Northern Africa, the Eastern, the Southern and the Sub-Saharan Africa. A combination of analytical tools was employed to meet the study objectives. Results: The results revealed that long run economic cost of HIV/AIDS had a statistical positive significant relationship with agricultural/economic growth. The results suggest that there is a curvilinear relationship between the course of the HIV/AIDS epidemic and agricultural/economic growth in terms of human capita development. Conclusions: HIV/AIDS pandemic interactions and agricultural growth have demonstrated that a more balanced approach is necessary for effective policy.

关键词： HIV/AIDS Plague Human Capita Development Risky Sex Etiquette Agricultural Policy Africa

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Analysis of a Cyclic Multicast Proxy Server Architecture

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International Journal of Communications, Network and System Sciences 2008年第4期1卷 301-306页

作者： Olatunde ABIONA Tricha ANJALI Clement ONIME lawrence kehinde 不详

The exponential growths of the World Wide Web (WWW) users have made the deployment of proxy servers popular on a network with limited resources. WWW clients perceive better response time, improved performance and speed when response to requested pages are served from the cache of a proxy server, resulting in faster response times after the first document fetch. This work proposes cyclic multicast as a scalable technique for improving proxy server performance for next generation networks. The proposed system uses a cyclic multicast engine for the delivery of popular web pages from the proxy server cache to increasingly large users under limited server capacity and network resources. The cyclic multicast technique would be more efficient for the delivery of highly requested web pages from the cache to large number of receivers. We describe the operation of the cyclic multicast proxy server and characterized the gains in performance.

关键词： Caching Cyclic Multicast Reliable Unicast Scalable Data Delivery Next Generation Network

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Reversal of acetaminophen-generated oxidative stress and concomitant hepatotoxicity by a phytopharmaceutical product

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Food Science and Human Wellness 2017年第1期6卷 20-27页

作者： Afolabi C.Akinmoladun kehinde O.Oguntunde lawrence O.Owolabi Omotayo B.Ilesanmi Joan O.Ogundele M.Tolulope Olaleye Afolabi A.Akindahunsi Phytomedicine Biochemical and Molecular Pharmacology and Toxicology LaboratoriesDepartment of BiochemistrySchool of SciencesThe Federal University of TechnologyPMB 704AkureNigeria Department of Biological Sciences Faculty of ScienceFederal University OtuokeOtuokeNigeria Department of Industrial Chemistry Faculty of ScienceFederal University Oye-EkitiPMB 373Oye-EkitiNigeria

The increasing popularity of herbal medicine and the well-established health benefits of phytochemicals have spurred the multiplicity of nutraceutical and phytopharmaceutical *** this study,Trévo^TM,a nutraceutical and phytopharmaceutical product,was evaluated for beneficial effects in acetaminophen-induced hepatic toxicity in Wistar *** received Trévo^TM(1.5 mL/kg,3.0 mL/kg or 4.5 mL/kg)orally for 14 *** was induced by the oral administration of acetaminophen(2 g/kg),24 h prior to *** liver function tests,oxidative stress indicators and histoarchitectural changes were *** administration occasioned significant increase(P<0.05)in serum bilirubin level and activities of the aminotransferases,alkaline phosphatase,γ-glutamyltransferase and lactate dehydrogenase accompanied by a significant decrease(P<0.05)in albumin level as well as histopathological alterations in liver *** of hepatic oxidative stress by acetaminophen was revealed by significant(P<0.05)increase in lipid peroxidation,depletion of reduced glutathione,and decrease in superoxide dismutase and catalase *** of Trévo^TM remarkably ameliorated acetaminophen-induced histopathological alterations and changes in serum and tissue biochemical *** protective effect of Trévo^TM(4.5 mL/kg)was at par with that of Silymarin(25 mg/kg).The present study indicates that Trévo^TM has notable salubrious effects.

关键词： Acetaminophen Antioxidant activity Hepatoprotection Nutraceutical Herbal supplement

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Development of Power Consumption Models for ESP8266-Enabled Low-Cost IoT Monitoring Nodes

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Advances in Internet of Things 2019年第1期9卷 1-14页

作者： Olubiyi O. Akintade Thomas K. Yesufu lawrence O. kehinde Department of Electronic and Electrical Engineering Obafemi Awolowo University Ile-Ife Nigeria

The development of energy and cost efficient IoT nodes is very important for the successful deployment of IoT solutions across various application domains. This paper presents energy models, which will enable the estimation of battery life, for both time-based and event-based low-cost IoT monitoring nodes. These nodes are based on the low-cost ESP8266 (ESP) modules which integrate both transceiver and microcontroller on a single small-size chip and only cost about $2. The active/sleep energy saving approach was used in the design of the IoT monitoring nodes because the power consumption of ESP modules is relatively high and often impacts negatively on the cost of operating the nodes. A low energy application layer protocol, that is, Message Queue Telemetry Transport (MQTT) was also employed for energy efficient wireless data transport. The finite automata theory was used to model the various states and behavior of the ESP modules used in IoT monitoring applications. The applicability of the models presented was tested in real life application scenarios and results are presented. In a temperature and humidity monitoring node, for example, the model shows a significant reduction in average current consumption from 70.89 mA to 0.58 mA for sleep durations of 0 and 30 minutes, respectively. The battery life of batteries rated in mAh can therefore be easily calculated from the current consumption figures.

关键词： IoT ESP8266 Power Model Event-Based Monitoring Time-Based Monitoring

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A User Identity Management Protocol for Cloud Computing Paradigm

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International Journal of Communications, Network and System Sciences 2011年第3期4卷 152-163页

作者： Safiriyu Eludiora Olatunde Abiona Ayodeji Oluwatope Adeniran Oluwaranti Clement Onime lawrence kehinde 不详

Cloud computing paradigm is a service oriented system that delivers services to the customer at low cost. Cloud computing needs to address three main security issues: confidentiality, integrity and availability. In this paper, we propose user identity management protocol for cloud computing customers and cloud service providers. This protocol will authenticate and authorize customers/providers in other to achieve global security networks. The protocol will be developed to achieve the set global security objectives in cloud computing environments. Confidentiality, integrity and availability are the key challenges of web services’ or utility providers. A layered protocol design is proposed for cloud computing systems, the physical, networks and application layer. However, each layer will integrate existing security features such as firewalls, NIDS, NIPS, Anti-DDOS and others to prevent security threats and attacks. System vulnerability is critical to the cloud computing facilities;the proposed protocol will address this as part of measures to secure data at all levels. The protocol will protect customers/cloud service providers’ infrastructure by preventing unauthorized users to gain access to the service/facility.

关键词： Cloud Computing Confidentiality Integrity Availability Identity Management Authentication

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A Load Balancing Policy for Distributed Web Service

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International Journal of Communications, Network and System Sciences 2010年第8期3卷 645-654页

作者： Safiriyu Eludiora Olatunde Abiona Ganiyu Aderounmu Ayodeji Oluwatope Clement Onime lawrence kehinde 不详

The proliferation of web services;and users appeal for high scalability, availability and reliability of web servers to provide rapid response and high throughput for the Clients’ requests occurring at anytime. Distributed Web Servers (DWSs) provide an effective solution for improving the quality of web services. This paper addresses un-regulated jobs/tasks migration among the servers. Considering distributed web services with several servers running, a lot of bandwidth is wasted due to unnecessary job migration. Having considered bandwidth optimization, it is important to develop a policy that will address the bandwidth consumption while loads/tasks are being transferred among the servers. The goal of this work is to regulate this movement to minimize bandwidth consumption. From literatures, little or no attention was given to this problem, making it difficult to implement some of these policies/schemes in bandwidth scarce environment. Our policy “Cooperative Adaptive Symmetrical Initiated Dynamic/Diffusion (CASID)” was developed using Java Development Environment (JADE) a middle ware service oriented environment which is agent-based. The software was used to simulate events (jobs distribution) on the servers. With no job transfer allowed when all servers are busy, any over loaded server process jobs internally to completion. We achieved this by having two different agents;static cognitive agents and dynamic cognitive agents. The results were compared with the existing schemes. CASID policy outperforms PLB scheme in terms of response time and system throughput.

关键词： Web Service Load Balancing Distributed Web Service Job Migration Quality of Web Service

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Wireless Network Security: The Mobile Agent Approach

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International Journal of Communications, Network and System Sciences 2013年第10期6卷 443-450页

The broadcast nature of wireless network makes traditional link-layer attacks readily available to anyone within the range of the network. User authentication is best safeguard against the risk of unauthorized access to the wireless networks. The present 802.1× authentication scheme has some flaws, making mutual authentication impossible and open to man-in-the-middle attacks. These characteristics make traditional cryptographic mechanism provide weak security for the wireless environment. We have proposed the use of mobile agents to provide dependable Internet services delivery to users, this will guarantee secure authentication in wireless networks and we examine the feasibility of our solution and propose a model for wireless network security.

关键词： Wireless Network Security Mobile Agent Authentication

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Proxy Server Experiment and Network Security with Changing Nature of the Web

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International Journal of Communications, Network and System Sciences 2014年第12期7卷 519-528页

作者： Olatunde Abiona Adeniran Oluwaranti Ayodeji Oluwatope Surura Bello Clement Onime Mistura Sanni lawrence kehinde Department of Computer Information Systems Indiana University Northwest Garry USA Department of Computer Science and Engineering Obafemi Awolowo University Ile-Ife Nigeria Information and Communication Technology Section Abdus Salam International Centre for Theoretical Physics Trieste Italy Department of Electrical and Electronic Engineering Obafemi Awolowo University Ile-Ife Nigeria

The total reliance on internet connectivity and World Wide Web (WWW) based services is forcing many organizations to look for alternative solutions for providing adequate access and response time to the demand of their ever increasing users. A typical solution is to increase the bandwidth;this can be achieved with additional cost, but this solution does not scale nor decrease users perceived response time. Another concern is the security of their network. An alternative scalable solution is to deploy a proxy server to provide adequate access and improve response time as well as provide some level of security for clients using the network. While some studies have reported performance increase due to the use of proxy servers, one study has reported performance decrease due to proxy server. We then conducted a six-month proxy server experiment. During this period, we collected access logs from three different proxy servers and analyzed these logs with Webalizer a web server log file analysis program. After a few years, in September 2010, we collected log files from another proxy server, analyzed the logs using Webalizer and compared our results. The result of the analysis showed that the hit rate of the proxy servers ranged between 21% - 39% and over 70% of web pages were dynamic. Furthermore clients accessing the internet through a proxy server are more secured. We then conclude that although the nature of the web is changing, the proxy server is still capable of improving performance by decreasing response time perceived by web clients and improved network security.

关键词： Proxy Server Network Security Hit Ratio Webalizer Proxy Log Analysis

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A Scalable Architecture for Network Traffic Monitoring and Analysis Using Free Open Source Software

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International Journal of Communications, Network and System Sciences 2009年第6期2卷 528-539页

作者： Olatunde ABIONA Temitope ALADESANMI Clement ONIME Adeniran OLUWARANTI Ayodeji OLUWATOPE Olakanmi ADEWARA Tricha ANJALI lawrence kehinde 不详

The lack of current network dynamics studies that evaluate the effects of new application and protocol deployment or long-term studies that observe the effect of incremental changes on the Internet, and the change in the overall stability of the Internet under various conditions and threats has made network monitoring challenging. A good understanding of the nature and type of network traffic is the key to solving congestion problems. In this paper we describe the architecture and implementation of a scalable network traffic moni-toring and analysis system. The gigabit interface on the monitoring system was configured to capture network traffic and the Multi Router Traffic Grapher (MRTG) and Webalizer produces graphical and detailed traffic analysis. This system is in use at the Obafemi Awolowo University, IleIfe, Nigeria;we describe how this system can be replicated in another environment.

关键词： Scalable Network Monitoring Traffic Analysis Web Log Analysis Open Source

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