Application of Computational Intelligence in Cognitive Radio Network for Efficient Spectrum Utilization, and Speech Therapy

communication systems utilize all the available frequency bands as efficiently as possible in time, frequency and spatial domains. Society requires more high capacity and broadband wireless connectivity, demanding greater access to spectrum. Most of the licensed spectrums are grossly underutilized while some spectrum (licensed and unlicensed) are overcrowded. The problem of spectrum scarcity and underutilization can be minimized by adopting a new paradigm of wireless communication scheme. Advanced Cognitive Radio (CR) network or Dynamic Adaptive Spectrum Sharing is one of the ways to optimize our wireless communications technologies for high data rates while maintaining users’ desired quality of service (QoS) requirements. Scanning a wideband spectrum to find spectrum holes to deliver to users an acceptable quality of service using algorithmic methods requires a lot of time and energy. Computational Intelligence (CI) techniques can be applied to these scenarios to predict the available spectrum holes, and the expected RF power in the channels. This will enable the CR to predictively avoid noisy channels among the idle channels, thus delivering optimum QoS at less radio resources. In this study, spectrum holes search using artificial neural network (ANN) and traditional search methods were simulated. The RF power traffic of some selected channels ranging from 50MHz to 2.5GHz were modelled using optimized ANN and support vector machine (SVM) regression models for prediction of real world RF power. The prediction accuracy and generalization was improved by combining different prediction models with a weighted output to form one model. The meta-parameters of the prediction models were evolved using population based differential evolution and swarm intelligence optimization algorithms. The success of CR network is largely dependent on the overall world knowledge of spectrum utilization in both time, frequency and spatial domains. To identify underutilized bands that can serve as potential candidate bands to be exploited by CRs, spectrum occupancy survey based on long time RF measurement using energy detector was conducted. Results show that the average spectrum utilization of the bands considered within the studied location is less than 30%. Though this research is focused on the application of CI with CR as the main target, the skills and knowledge acquired from the PhD research in CI was applied in ome neighbourhood areas related to the medical field. This includes the use of ANN and SVM for impaired speech segmentation which is the first phase of a research project that aims at developing an artificial speech therapist for speech impaired patients.Petroleum Technology Development Fund (PTDF) Scholarship Board, Nigeri

Optimized Artificial Neural Network Using Differential Evolution for Prediction of RF Power in VHF/UHF TV and GSM 900 Bands for Cognitive Radio Networks

Cognitive radio (CR) technology has emerged as a promising solution to many wireless communication problems including spectrum scarcity and underutilization. The knowledge of Radio Frequency (RF) power (primary signals and/ or interfering signals plus noise) in the channels to be exploited by CR is of paramount importance, not just the existence or absence of primary users. If a channel is known to be noisy, even in the absence of primary users, using such channels will demand large quantities of radio resources (transmission power, bandwidth, etc) in order to deliver an acceptable quality of service to users. Computational Intelligence (CI) techniques can be applied to these scenarios to predict the required RF power in the available channels to achieve optimum Quality of Service (QoS). While most of the prediction schemes are based on the determination of spectrum holes, those designed for power prediction use known radio parameters such as signal to noise ratio (SNR), bandwidth, and bit error rate. Some of these parameters may not be available or known to cognitive users. In this paper, we developed a time domain based optimized Artificial Neural Network (ANN) model for the prediction of real world RF power within the GSM 900, Very High Frequency (VHF) and Ultra High Frequency (UHF) TV bands. The application of the models produced was found to increase the robustness of CR applications, specifically where the CR had no prior knowledge of the RF power related parameters. The models used implemented a novel and innovative initial weight optimization of the ANN’s through the use of differential evolutionary algorithms. This was found to enhance the accuracy and generalization of the approac

Optimized Neural Network Using Differential Evolutionary and Swarm Intelligence Optimization Algorithms for RF Power Prediction in Cognitive Radio Network: A Comparative study

Cognitive radio (CR) technology has emerged as a promising solution to many wireless communication problems including spectrum scarcity and underutilization. The a priory knowledge of Radio Frequency (RF) power (primary signals and/ or interfering signals plus noise) in the channels to be exploited by CR is of paramount importance. This will enable the selection of channel with less noise among idle (free) channels. Computational Intelligence (CI) techniques can be applied to these scenarios to predict the required RF power in the available channels to achieve optimum Quality of Service (QoS). In this paper, we developed a time domain based optimized Artificial Neural Network (ANN) model for the prediction of real world RF power within the GSM 900, Very High Frequency (VHF) and Ultra High Frequency (UHF) TV bands. The application of the models produced was found to increase the robustness of CR applications, specifically where the CR had no prior knowledge of the RF power related parameters such as signal to noise ratio, bandwidth and bit error rate. The models used, implemented a novel and innovative initial weight optimization of the ANN’s through the use of differential evolutionary and swarm intelligence algorithms. This was found to enhance the accuracy and generalization of the ANN model. For this problem, DE/best/1/bin was found to yield a better performance as compared with the other algorithms implemented

Spectrum Hole Prediction And White Space Ranking For Cognitive Radio Network Using An Artificial Neural Network

With spectrum becoming an ever scarcer resource, it is critical that new communication systems utilize all the available frequency bands as efficiently as possible in time, frequency and spatial domain. rHowever, spectrum allocation policies most of the licensed spectrums grossly underutilized while the unlicensed spectrums are overcrowded. Hence, all future wireless communication devices beequipped with cognitive capability to maximize quality of service (QoS); require a lot of time and energartificial intelligence and machine learning in cognitive radio deliver optimum performance. In this paper, we proposed a novel way of spectrum holes prediction using artificial neural network (ANN). The ANN was trained to adapt to the radio spectrum traffic of 20 channels and the trained network was used for prediction of future spectrum holes. The input of the neural network consist of a time domain vector of length six i.e. minute, hour, date, day, week and month. The output is a vector of length 20 each representing the probability of the channel being idle. The channels are ranked in order of decreasing probability of being idleminimizing We assumed that all the channels have the same noise and quality of service; and only one vacant channel is needed for communication. The result of the spectrum holes search using ANN was compared with that of blind linear and blind stochastic search and was found to be superior. The performance of the ANN that was trained to predict the probability of the channels being idle outperformed the ANN that will predict the exact channel states (busy or idle). In the ANN that was trained to predict the exact channels states, all channels predicted to be idle are randomly searched until the first spectrum hole was found; no information about search direction regarding which channel should be sensed first

Spectrum Occupancy Survey in Leicester, UK, For Cognitive Radio Application

Cognitive radio (CR) technology has emerged as a promising solution to many wireless communication problems including spectrum scarcity and underutilization. Knowing the current state of spectrum utilization in frequency, time and spatial domain will enhance the implementation of CR network. In this paper, we evaluate the spectrum utilization of some selected bands in Leicester city, UK; based on long time spectrum measurements using energy detection method. This study provides evidence of gross underutilization of some licenses spectrum which can be exploited by CR for efficient spectrum utilization

Towards Artificial Speech Therapy: A Neural System for Impaired Speech Segmentation

This paper presents a neural system-based technique for segmenting short impaired speech utterances into silent, unvoiced, and voiced sections. Moreover, the proposed technique identifies those points of the (voiced) speech where the spectrum becomes steady. The resulting technique thus aims at detecting that limited section of the speech which contains the information about the potential impairment of the speech. This section is of interest to the speech therapist as it corresponds to the possibly incorrect movements of speech organs (lower lip and tongue with respect to the vocal tract). Two segmentation models to detect and identify the various sections of the disordered (impaired) speech signals have been developed and compared. The first makes use of a combination of four artificial neural networks. The second is based on a support vector machine (SVM). The SVM has been trained by means of an ad hoc nested algorithm whose outer layer is a metaheuristic while the inner layer is a convex optimization algorithm. Several metaheuristics have been tested and compared leading to the conclusion that some variants of the compact differential evolution (CDE) algorithm appears to be well-suited to address this problem. Numerical results show that the SVM model with a radial basis function is capable of effective detection of the portion of speech that is of interest to a therapist. The best performance has been achieved when the system is trained by the nested algorithm whose outer layer is hybrid-population-based/CDE. A population-based approach displays the best performance for the isolation of silence/noise sections, and the detection of unvoiced sections. On the other hand, a compact approach appears to be clearly wellsuited to detect the beginning of the steady state of the voiced signal. Both the proposed segmentation models display outperformed two modern segmentation techniques based on Gaussian mixture model and deep learning

An Optimized Hybrid Dynamic Bayesian Network Approach using Differential Evolution Algorithm for the Diagnosis of Hepatocellular Carcinoma

Computational Intelligence methods have been applied to the automatic discovery of predictive models for the diagnosis of Hepatocellular Carcinoma (a.k.a liver cancer). Evolutionary algorithms have lent themselves as efficient and robust methods for evolving best parameter values that optimize feature selection methods. Different computational methods for discovering more robust set of molecular features for liver cancer have been proposed. These include methods combining other nature-inspired evolutionary algorithms such as Particle Swarm Optimization, with classifiers like Support Vector Machine (SVM). In this paper, we apply different variants of Differential Evolution algorithm to optimize the parameters of feature selection algorithms using a proposed two-stage approach. Stage one fine-tunes the parameters of the feature selection methods and selects high quality features. In stage two, Dynamic Bayesian Network (DBN) is applied to infer temporal relationships of the selected features. We demonstrate our method using gene expression profiles of liver cancer patients. The results show that the SVM-based predictive model with the radial basis function kernel yielded a predictive accuracy of 100%. This model and a sub-set of the features consist of only 8 features (genes) that have been regarded as most informative set for the diagnosis of the disease. In addition, among all these eight genes, the DBN model of the selected features reveals that SPINT2 gene inhibits HGF activator which prevents the formation of active hepatocytes growth factor, which makes up over 80% of liver cells

Christian Muslim conflict in Nigeria: An appraisal

Nigeria as a whole is bedeviled with a lot of social vices and different kind of atrocities such as killings of fellow humans, bribery and corruption, drug abuse and addiction, stealing and robbery, human trafficking and a host of others. All have bedeviled our dear nation and the world at large. The hearts are not pure as such there is a frequency of Religious conflicts which have claimed the lives of innocent citizens and properties worth millions of naira. It is unfortunate that despite all the efforts by Religious and individual organizations in Nigeria through religious dialogue, peace has remained a mirage. On a good day religion that is supposed to be an arena of peaceful relations unfortunately turns out to be the platform many often use to mastermind evil. In Nigeria the adherents of Christianity and Islam with the various sects within them have clashed over situational supremacy and power tussle. This paper aims at examining conflicts among the Christians and Muslims which is a challenge to the Nigerian society, unemployment, poverty, commercialization of the conflicts are the root courses of the interfaith conflicts among the Abrahamic faith and that have led to the destruction of lives and properties. The paper shall employ descriptive methods in carrying out the research. We must transcend religious difference and relate harmoniously with each other as fellow humans beings, as the situation has not reached the hopeless and fatal stage. For if we are looking forward to building a great nation that will impact the world, then we must live in a nation that is devoid of any form of ethno-religious conflict and if that is achieved there will be no loss of lives and property, and our political arena will also be devoid of politics of religion, elections will only be based on capability

Differential Evolution Schemes for Speech Segmentation: A Comparative Study

This paper presents a signal processing technique for segmenting short speech utterances into unvoiced and voiced sections and identifying points where the spectrum becomes steady. The segmentation process is part of a system for deriving musculoskeletal articulation data from disordered utterances, in order to provide training feedback. The functioning of the signal processing technique has been optimized by selecting the parameters of the model. The optimization has been carried out by testing and comparing multiple Differential Evolution implementations, including a standard one, a memetic one, and a controlled randomized one. Numerical results have also been compared with a famous and efficient swarm intelligence algorithm. For the given problem, Differential Evolution schemes appear to display a very good performance as they can quickly reach a high quality solution. The binomial crossover appears, for the given problem, beneficial with respect to the exponential one. The controlled randomization appears to be the best choice in this case. The overall optimized system proved to segment well the speech utterances and efficiently detect its uninteresting parts

Optimized Neural Network Using Differential Evolutionary and Swarm Intelligence Optimization Algorithms for RF Power Prediction in Cognitive Radio Network: A Comparative Study

Abstract-Cognitive radio (CR) technology has emerged as a promising solution to many wireless communication problems including spectrum scarcity and underutilization. The a priory knowledge of Radio Frequency (RF) power (primary signals and/ or interfering signals plus noise) in the channels to be exploited by CR is of paramount importance. This will enable the selection of channel with less noise among idle (free) channels. Computational Intelligence (CI) techniques can be applied to these scenarios to predict the required RF power in the available channels to achieve optimum Quality of Service (QoS). In this paper, we developed a time domain based optimized Artificial Neural Network (ANN) model for the prediction of real world RF power within the GSM 900, Very High Frequency (VHF) and Ultra High Frequency (UHF) TV bands. The application of the models produced was found to increase the robustness of CR applications, specifically where the CR had no prior knowledge of the RF power related parameters such as signal to noise ratio, bandwidth and bit error rate. The models used, implemented a novel and innovative initial weight optimization of the ANN's through the use of differential evolutionary and swarm intelligence algorithms. This was found to enhance the accuracy and generalization of the ANN model. For this problem, DE/best/1/bin was found to yield a better performance as compared with the other algorithms implemented