Department Of Computer Science

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https://ir.unilag.edu.ng/handle/123456789/3381
The overall philosophy of Computer Sciences degree programmes in the Faculty of Science is to produce graduates with fully integrated science knowledge so that they can have a sound background required to fully understand the theoretical base of Computer Science.

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    Open Access
    Information Visualisation: A truly Interdisciplinary field of study
    (Journal of computer science and its applications, 2004) Adewole, A. Philips; Sofoluwe, A.B.
    In this paper, we create awareness and also promote the study of information visualization. We designed and administered questionnaires to determine the present level of awareness and our results show that presently, the level of awareness is very low. We illustrate with examples the use of information visualization and we give recommendations as to how visualization can assist researchers and decision makers in having better understanding about the relationships, flaws, and structure inherent in their underlying datasets.
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    Open Access
    A Survey of Software Reengineering Approaches
    (Journal of Computer Science and its Applications, 2004) Okunoye, O. B.; Uwadia, C. O.; Oladeji, F.A.
    For any developed software system not to become progressively less useful in real-world environment, such software is expected to be efficient, reliable and amendable to support new platforms, embrace emerging standards, satisfy new customer needs, and enhance better understanding of technological advancements. As a result of the new evolving requirements, it could be cost effective to rewrite, or upgrade some software systems. However, there are some legacy software systems that are too valuable to be replaced or rewritten because of their sheer size and complexity. Maintaining such legacy systems could be Very expensive. Therefore, such legacy software systems need to be reengineered so as to meet these requirements. We surveyed various approaches adopted and tools used in software reengineering with emphasis on program comprehension. In addition, the need for software reengineering is discussed. Software reengineering process activities are enumerated. Some"o(the approaches, especially' for program understanding through reverse engineering are investigated.
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    Open Access
    A Visualization Approach to Graph Layout Problem.
    (ASSET Journal of Applied Sciences, 2006) Adewole, A.P.; Sofoluwe, A.B.
    A comprehensive assessment of existing graph layout algorithms revealed that most of the existing algorithms employed automatic approach which permits graph layout without user intervention. However, automatic approach poses some difficulties: (1) user or application-specific layout constraints are usually not taken into account. (2) automatic approach seldom makes use of information in the current layout for the next incremental update. (3) fixed node size is commonly being used. To overcome these difficulties, an interactive graph layout system, A Visualization Approach to Graph Layout Problem, AVATGLP based on modified force-directed algorithm was developed. The system revealed that a user or application-specific constraint may be easily added to many automatic graph layout algorithms, and that using information in the current layout incremental update coupled with variable node size, leads to a better graph layout. This study will aid researchers, managers, e.t.c in gaining new insights and ideas about the relationships inherent in their data-set, and is, therefore, very useful for building sophisticated research tools.
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    Open Access
    Drawing Graphs with Modified Simulated Annealing Algorithm
    (Journal of Computer Science and its Applications, 2006-06) Adewole, A.P.
    This paper illustrates a modified simulated annealing algorithm for drawing graphs according to a number of aesthetic criteria. The proposed modified algorithm used in this paper combined the power of simulated annealing algorithm and mouse events available in java to enhance graph readability. Tests are carried out on two graphs of increasing difficulty, and the results show that this approach draws graph nicely and at the same time meets some of the aesthetic criteria stated in this work.
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    Open Access
    A Revised Logic for Weighted Round Robin Scheduler towards Improving Network Throughput in a QoS Internet
    (Journal of Computer Science and its Applications, 2007-06) Oladeji, F.A.; Uwadia, C. O.; Kourie, D.G.; Strauss, D.M.
    Attempts to support service differentiation and QoS on the internet have brought about various traffic management models. One such class of models deals with traffic scheduling at the Internet routers. A network scheduler generally implements three orthogonal policies, namely: a scheduling policy, a queuing policy and a packet drop policy. While the three policies work together to prevent a network collapse in face of congestions, this paper focuses on weighted round robin (WRR) policy and seeks how its performance can be improved in the face of bursty traffic situations. WRR allocates available resources in proportion to the prescribed weight. The early implementation of the scheduler was faced with performance degradation when the algorithm meets with bursty input traffic. in such a situation, queues might bot be served even through there is still bandwidth. this paper presents dynamic algorithm that caters for such lapses in this scheduler. Our scene tagged carry-on WRR (cWRR) made sure the remaining bandwidth is used up by other backlogged queues in the same round. The new scheme was simulated in Java and our observation shows that the throughput achieved was improved when compared to ordinary WRR scheduling discipline.
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    Open Access
    Comparative Evaluation of Available Bandwidth Estimation Tools (PRTG and OAUENTMON) in a Campus-Wide Area Network.
    (The Pacific Journal of Science and Technology, Akamai University, USA, 2009) AZEEZ, Nureni
    In recent years, there has been a strong interest in measuring the available bandwidth of network paths. Several methods and techniques have been proposed and various measurement tools have been developed and evaluated. However, there have been few comparative studies with regard to the actual performance of these tools. This project presents a study of available bandwidth measurement techniques for both PRTG and OAUNETMON and undertakes a comparative analysis in terms of accuracy, intrusiveness and response time of active probing tools. Finally, measurement errors and uncertainty of the tools are analyzed and overall conclusions were made.
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    Open Access
    Evolutionary simulated annealing with application to tournament traveling problem
    (Journal of Computer Science and its Applications, 2009) Adewole, A.P.; Ejide, F.O
    This paper describes evolutionary simulated annealing approach to the solution of TTP that includes both feasible and infeasible schedules. The approach uses a large neighbourhood with complex moves and includes techniques such as perturb, pervert and score t balance the exploration of the feasible and infeasible regions and to escape local minimal at very low temperatures. Experimental results show that, in practical cases, the optimal solution can be found in reasonable time, for small instances of n.
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    Open Access
    The Significance of Traffic Admission Control and Scheduling Mechanism in a QoS Internet Router
    (International Journal of Wireless and Mobile Computing, 2010) Oladeji, F.A.; Uwadia, C. O.; Oyetunji, M.O.; Adeyemi, M.
    Internet real-time users are often confronted with network congestive messages such at "network busy, try later' due to the limitations and constraints of its TCP/IP traffic management protocols to support real-time applications. Four about a decade now, research effort has been directed on the extension of the TCP/IP protocol to fully support and grant the quality required by multimedia applications. Outcome of such extensions led to the proposition of Differentiated Service platforms [1] where users' expectations could be granted relative to agreed traffic profiles at the routers. A key requirement for such paradigm to work effectively is the application of differential packet scheduling and buffer admission mechanisms at the routers from source to destination. Thus, the Internet Engineering Task Force {IElF), through its request for comment for attaining OoS is searching for better algorithm to achieve OoS, maximize the use of scarce resources, minimize packet delay, loss rate and improve fairness in the network. Having studied various buffer management and scheduling processes from various Internet quality of service researchers in [2,3,4, 5 and 6], we present a modified quality of service-based traffic metering and admission logic, termed a revised token bucket traffic policer for the Internet router. The algorithm followed the traffic management propositions by the IETF and came out with better network performance in terms of packet loss rate and throughput. We carried out the simulation using C# a programming language tool and. We evaluate the performance of our algorithm with the former logic of a token bucket meter and observed that traffic sources and future real-time Internet service providers will receive fairer treatment when few packets are droStaff pped. This will consequentially improve the reliance of e-mobile providers on the Internet.
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    Open Access
    A Random Walk Model for Stock Market Prices
    (Journal of Mathematics and Statistics, 2010) Agwuegbo, S.O.N.; Adewole, A.P.; Maduegbuna, A.N.
    Abstract: Problem statement: The stock exchange market has been one of the most popular investments in the recent past due to its high returns. The market has become an integral part of the global economy to the extent that any fluctuation in this market influences personal and corporate financial lives and the economic health of a country. The daily behavior of the market prices revealed that the future stock prices cannot be predicted based on past movements. Approach: In this study, we analyzed the behavior of daily return of Nigerian stock market prices. The sample included daily market prices of all securities listed in the Nigeria Stock Exchange (NSE). Results: The result from the study provided evidence that the Nigerian stock exchange is not efficient even in weak form and that NSE follow the random walk model. The idealized stock price in the Nigerian stock exchange is a martingale. Conclusion: Martingale defines the fairness or unfairness of the investment and no investor can alter the stock price as defined by expectation.
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    Open Access
    Predicting Insurance Investment: A Factor Analytic Approach
    (Journal of Mathematics and Statistics, 2010) Agwuegbo, S.O.; Adewole, A.P.; Maduegbuna, A.N.
    Problem statement: In the last decade growing attention has been paid to the pattern of investments by the insurance industry and the question of how to evaluate such investments. In an economy where the capital market is huge and active, mathematical considerations come into play in the selection of investments to ensure yield maximisation. Approach: This study examined the use of factor analysis as an emerging technique for the analysis of insurance investment in Nigeria. Results: The proposed technique described a number of methods designed to analyze interrelationships within the investment variables in terms of few underlying but unobservable random quantities called factors. The factors were constructed in a way that reduces the overall complexity of the data by taking advantage of inherent interdependencies. Conclusion: The result obtained through this approach were promising and shows that two principal components of the factor loadings have a cumulative proportion of variance accounted for 94.5% of the total variations of the investments pattern.
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    Open Access
    FACTORS AFFECTING THE USE AND ADOPTION OF OPEN-SOURCE SOFTWARE DEVELOPMENT PROCESS AMONG NIGERIAN UNDERGRADUATE STUDENTS
    (Computing, Information Systems, Development Informatics & Allied Research Journal, 2010-06) Odulaja, G.O.; Ogude, U.C.; Adebimpe, A.L; Akinyosade, E.O.
    Using a questionnaire titled “Factors Affecting the Use and Adoption of Open-Source Software Development Process Among Nigerian Undergraduates” to solicit responses in selected Institutions of Higher learning in Nigeria, we investigated the factors that motivate or prevent students from adopting and using the open-source paradigm for software development. Findings from the analysis of data obtained from the research showed that students are keen about using the open source software platforms as a means of developing software system. However, there are concerns among students of the implication of collaborative efforts on open source platforms on project completion time, equitable access to internet facilities and metrics for assessing individual contributions to the success of the final product from such development process. We conclude by making recommendations on how open-source platforms can be used among students
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    Open Access
    Digital Filter Design Using Artificial Neural Network.
    (Journal of Computer Science and its Applications, 2010-06) Adewole, A.P.; Agwuegbo, S.O.
    In this paper, Feed Forward Multi-Layer Perceptron neural network was adapted as a digital filtering tool in modelling communications systems that were corrupted by noise or interference. Discrete-Fourier Transform was used to reduce error in transmission. The input and target output data from the study were generated using ionosphere data radar, and this proved to be essential and necessary for training and testing the network. The network was trained using MATLAB R2008a and the training resulted to the minimisation of the error. The result of digit filtration shows a near error-free output. In conclusion, the forward-feed multilayered neural network can be used to build a functional digital filter.
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    Open Access
    COMPARISON OF NEURAL NETWORK AND MULTIVARIATE DISCRIMINANT ANALYSIS IN SELECTING NEW COWPEA VARIETY
    (International Journal of Computer Science and Information Security (IJCSIS), 2010-07) Adewole, Adetunji Philip; Sofoluwe, A. B.; Agwuegbo, Samuel Obi-Nnamdi
    In this study, neural networks (NN) algorithm and multivariate discriminant (MDA) based model were developed to classify ten (10) varieties of cowpea which were widely planted in Kano. . In order to demonstrate the validity of our model, we use the case study to build a neural network model using Multilayer Feedforward Neural Network, and compare its classification performance against the Multivariate discriminant analysis. Two groups of data (Spray and Nospray) were used. Twenty kernels were used as training data set and test data to classify cowpea seed varieties. The neural network classified the new cowpea seed varieties based on the information it is trained with. At the end both methods were compared for their strength and weakness. It is noted that NN performed better than MDA, so that NN could be considered as a support tool in the process of selection of new cowpea varieties.
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    Open Access
    State-space models for analysis of hydrological series
    (Journal of Engineering Research, 2010-12) Agwuegbo, S.O.N.; Adewole, A.P.
    In this study, the class of state pace model for which optimal forecasts may be computed using a recursive estimation procedure called the Kalman Filter is developed for the analysis of hydrological series. The state-space formulation yields a practical means of estimation for his complex time varying dynamical process. It provided a generic and flexible framework for hydrological modelling and inference. A straight forward implementation was achieved in the software package S-Plus
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    Open Access
    Artificial Neural Network Model for Forecasting Foreign Exchange Rate
    (World of Computer Science and Information Technology Journal, 2011) Adewole, Adetunji Philip; Akinwale, Adio Taofiki; Akintomide, Ayo Bidemi
    The present statistical models used for forecasting cannot effectively handle uncertainty and instability nature of foreign exchange data. In this work, an artificial neural network foreign exchange rate forecasting model (AFERFM) was designed for foreign exchange rate forecasting to correct some of these problems. The design was divided into two phases, namely: training and forecasting. In the training phase, back propagation algorithm was used to train the foreign exchange rates and learn how to approximate input. Sigmoid Activation Function (SAF) was used to transform the input into a standard range [0, 1]. The learning weights were randomly assigned in the range [-0.1, 0.1] to obtain the output consistent with the training. SAF was depicted using a hyperbolic tangent in order to increase the learning rate and make learning efficient. Feed forward Network was used to improve the efficiency of the back propagation. Multilayer Perceptron Network was designed for forecasting. The datasets from oanda website were used as input in the back propagation for the evaluation and forecasting of foreign exchange rates. The design was implemented using matlab7.6 and visual studio because of their supports for implementing forecasting system. The system was tested using mean square error and standard deviation with learning rate of 0.10, an input layer, 3 hidden layers and an output layer. The best known related work, Hidden Markov foreign exchange rate forecasting model (HFERFM) showed an accuracy of 69.9% as against 81.2% accuracy of AFERFM. This shows that the new approach provided an improved technique for carrying out foreign exchange rate forecasting.
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    Open Access
    ANCAEE: A Novel Clustering Algorithm for Energy Efficiency in Wireless Sensor Networks
    (Wireless Sensor Network, 2011) AZEEZ, Nureni
    One of the major constraints of wireless sensor networks is limited energy available to sensor nodes because of the small size of the batteries they use as source of power. Clustering is one of the routing techniques that have been using to minimize sensor nodes’ energy consumption during operation. In this paper, A Novel Clustering Algorithm for Energy Efficiency in Wireless Sensor Networks (ANCAEE) has been proposed. The algorithm achieves good performance in terms of minimizing energy consumption during data transmis-sion and energy consumptions are distributed uniformly among all nodes. ANCAEE uses a new method of clusters formation and election of cluster heads. The algorithm ensures that a node transmits its data to the cluster head with a single hop transmission and cluster heads forward their data to the base station with multi-hop transmissions. Simulation results show that our approach consumes less energy and effectively extends network utilization.
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    Open Access
    A Genetic Algorithm for Solving Travelling Salesman Problem
    (International Journal of Advanced Computer Science and Applications, 2011) Adewole, P.; Akinwale, A.T.; Otunbanowo, K
    In this paper we present a Genetic Algorithm for solving the Travelling Salesman problem (TSP). Genetic Algorithm which is a very good local search algorithm is employed to solve the TSP by generating a preset number of random tours and then improving the population until a stop condition is satisfied and the best chromosome which is a tour is returned as the solution. Analysis of the algorithmic parameters (Population, Mutation Rate and Cut Length) was done so as to know how to tune the algorithm for various problem instances.
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    Open Access
    SIMULATED ANNEALING FOR SOLVING THE TRAVELLING SALESMAN PROBLEM
    (Journal of Natural Sciences, Engineering and Technology, 2011) ADEWOLE, A.P.; AGWUEGBO, S.O.N.; OTUBAMOWO, K.
    In this paper we considered the use of Simulated Annealing for solving the Travelling Salesman Problem (TSP) which is NP-Complete. The algorithm searches solutions for the global minimum by perturbing existing solutions and replace if the new solution is better than the existing solution. The annealing process is controlled by some algorithmic parameters and thus the solution relies on the parameters set. Different parameters were used to know the best set of parameters. Generally the algorithm was tested and proved to be a good solver of TSP.
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    Open Access
    Structural Model for the Analysis of Stock Market Price Index
    (International Journal of Marketing Studies, 2011) Agwuegbo, S.O.N.; Mojekwu, J.N.; Adewole, A.P.; Maduegbuna, A.N.
    Stock market returns are predictable from a variety of financial and macroeconomic variables and have long been an attraction for equity investors. Recently increasing attention has shifted on the market index as a method of measuring a section of the stock market. The stock market index is regarded as an important indicator by the investing public at large and can be used as a benchmark by which investor or fund manager compares the returns of their own portfolio. In this study, attempts are made to model the Nigerian stock market index using a structural model. The procedure is based on the relationship between the state space and the autoregressive moving average (ARMA) model. The time series procedure from S-PLUS software is used in the analysis. The result obtained shows that the Nigerian stock market price index is an autoregressive model (AR) of order 1. It is also found that the AIC is at minimum at lag 1which corresponds to the same model identified for the series by using the sample ACF and PACF.
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    Open Access
    A Receipt-free Multi-Authority E-Voting System
    (International Journal of Computer Applications, 2011-09) Adewole, A.P.; Sodiya, A.S.; Arowolo, O.A.
    The existing e-voting schemes satisfied requirements such as eligibility, completeness, „no vote duplication‟, privacy but have not been able to solve the problems of universal verifiability, coercion, bribery and fairness in the overall election process. In this work, a receipt-free multi-authority e-voting system is proposed to solve the drawbacks of the existing e-voting systems is proposed. The proposed scheme employs ElGamal encryption for ensuring the security of votes because of its probabilistic nature. ElGamal which is homomorphic with multiplication is modified to be additive homomorphic in order to ensure voters‟ privacy and overall election efficiency. A trusted centre is involved in the scheme to distribute the shared secret key among the authorities and the Shamir(t, n) threshold scheme is used for key distribution. The authorities will then use this share secret to decrypt the encrypted ballot. 1-out-of-L re- encryption is used to guarantee receipt-freeness. The proposed scheme is divided into registration, validation, vote casting and tallying phases. The security analysis of the scheme was then carried out to show its effectiveness.