Theses & Dissertations

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https://hdl.handle.net/20.500.14170/209

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  • Publication
    2-D wavelength/time MDW code optimization for cardinality enhancement in OCDMA system
    ( 2018)
    Amy Azura Mohamad Saufe
    The explosive growth of bandwidth demand, together with advance in latest communication services and emerging applications has inspired huge interest in application of code division multiple access (CDMA) technique in optical network. As a core of an optical code division multiple access (OCDMA) system, several multiple access techniques have been created for optical fiber correspondence. The aim of using OCDMA is to overcome the multiple access interference (MAI) noise and phase induced intensity noise (PIIN) which encourages the amount of bit error rate (BER). The MAI and PIIN can be reduced and suppress by using the perfect code property with minimum crosscorrelation. In this thesis, the incoherent two-dimensional (2-D) wavelength/time (W/T) modified double weight (MDW) code OCDMA is analysed and demonstrated. The allocation of W/T in this thesis is to make the system asynchronously continuous with time without any objection. The good result in optimum PIIN suppression in comparison within the proposed 2-D MDW code with other codes such as 2-D Perfect Difference Code (PDC) and 1-D MDW code. The 2-D W/T MDW code achieves high scalability with the improvement in term of cardinality, bit rate, bit error rate (BER) and distance. At 10-9 (BER), the code cardinality reaches 251 simultaneous number of users and the lowest effective received power (𝑃𝑃𝑠𝑠𝑠𝑠) is achieved at -16.5 dBm. By comparing within parameter; avalanche photodiode (APD) are achieved 19 km longer compare with PIIN photodiode there is 18 km in this system. Thus, the 2-D W/T MDW OCDMA code simulation has successfully reduced MAI and suppress PIIN which result in optical fiber length and effective received power.
  • Publication
    3D frequency selective surfaces for structural health monitoring systems
    ( 2017)
    Syaiful Anas Suhaimi
    The research work in this dissertation mainly highlighted to the study of capability 3D Frequency Selective Surfaces to act as a sensor in structure monitoring. A new type of three-dimensional (3D) Frequency Selective Surfaces (FSS) applied for passive sensing in Structural Health Monitoring (SHM) is presented. Square shape FSS are chosen in this research which it able to govern the sensitivity of frequency response. Moreover, these FSSs are modified in a 3D form to feature enhanced performance compared to conventional FSSs and sensors. More specifically, the proposed 3D FSS is able to control its sensitivity |S21| in either TE or TM incident waves. In this research, incident angle characteristics are evaluated for SHM application to obtain angular responses of up to 80 degrees. The resonant behavior of the TE-incident wave is shown to be sensitive towards the incident angle and is suitable to be used for monitoring any building tilting and damages. This is due to the significant 3D length hanges of the conductor elements. Meanwhile, the TM-incident wave is found to be insensitive (frequency operation not shifting) towards the incident angle. There have some novelty have been introduced in this work such 3D FSS give an extra advantage to perform as a passive sensor and equation for relation between frequency response and incident angle are derived.
  • Publication
    5.8 GHz of circularly polarized microstrip array antenna for point-to-point application
    ( 2021)
    Nurasma Husna Mohd Sabri
    These research project is mainly focused on the development of Circularly Polarized Microstrip Array Antenna for Point-to-Point Application. The antenna for point-to-point application is develop to transmit and received the communication signal. Usually, the point-to-point application required two station to communicate to each other like a base station. The antenna at a base station are placed at a high place to avoid out the interferences. In this research, microstrip antenna which have light weight characterize is design to ease the installation for the base station. The circular polarization is proposed to limit the limitation of linear polarization which is less reliable in base station antenna. The circular polarization antenna is made to allow the receiver constantly receive the power at any wave angle and make the transmission between two antennas are more constant. The circular polarization antenna is realized by applying 3 different techniques in the design which are truncated-edge, inclined slot and side feed. The array antenna is implement in this research in order to increase the antenna gain which is required in point-to-point application. The proposed design was compared by 3 difference array configuration which are 1x1 array, 2x1 array and 2x2 array etched on Rogers RT 5880 substrate with 2.2 and 0.51 mm of dielectric constant and thickness respectively. Multilayer substrate antenna is made to increase the thickness of the substrate which is layered by 3 layers of Rogers RT 5880 which makes the thickness of the antenna is 1.53 mm. These 3 design produced circular polarization antenna since obtained the axial ratio below than 3 dB. The 2x2 array antenna produce circular polarization capability which have the axial ratio of 1.54 dB and also obtained are high gain of 13.27 dB. The antenna is operated at 5.8 GHz which is an ideal frequency for point to point communication that used in base station application.
  • Publication
    A classification of EMG signal from masseter and buccinators, muscles to control the directional movement of power-assisted wheelchair
    ( 2016)
    Hayder Abdulazeez Yousif Al-Yasari
    There are many people who cannot control the movement of their upper or lower limbs. Also, there are many people affected with some form of paralysis, suffering from a spinal cord injury, and many elderly people are unable to control their upper and lower limbs. Therefore, it is necessary to provide them with an alternative control device that can help them to achieve some mobility independence, where the wheelchair is very important for these people to help them in their daily lives for moving from one place to another in a comfortable manner. The main objective of this research work is to control the movements of the wheelchair in five directions (forward, reverse, stop, left and right), using signals from the masseter and buccinators muscles as control signals. Then extracted the features of the autoregressive model, waveform length, mean absolute value and root mean square, and then classify them by using a K-nearest neighbor classifier and linear discriminant analysis to choose the better result of the classification and utilize it as a control signals for the wheelchair movement in offline method. The result of classification shows that the accuracy of the K-nearest neighbor classifier is very higher compared with the linear discriminant analysis classifier, where the highest rate of accuracy was 98.88% when using the KNN classifier with the AR model 4-order.
  • Publication
    A compact and high gain circularly polarized antenna for CubeSat S-band application
    ( 2018)
    Abdul Halim Lokman
    This project focuses on a compact antenna with high gain and circular polarization for S-band CubeSat application. CubeSat is categorized as a type of pico-satellite with a dimension of 10 x 10 x 10 cm3. By utilizing the component-of-the-shelf (COTS), this class of pico-satellite is capable of reducing the development cost and time compared to commercial satellites in segments such as space research, earth observation, inter-satellite communication, and the educational purpose. Due to the CubeSat’s size and weight constraints, most of their antennas are integrated with deployment mechanisms. One of the most popular deployable mechanisms used in CubeSats is the tape spring mechanism. In this project, two types of high gain circularly polarized antenna is designed to comply with 1U and 3U CubeSat at S-band frequency. A compact circularly polarized antenna is designed with a size of 55 x 55 x 0.85 mm3. The antenna operates with at least -10 dB of reflection coefficient, at least 3 dB of axial ratio and a gain of 3.84 dBi at 2.4 GHz. The antenna propagates with a right-handed circular polarization (RHCP) at 0° azimuth, and left-handed circular polarization (LHCP) at 180° azimuth. Such gain level needs to be improved for long-range CubeSat communication. A reflectarray is then designed to obtain an improved simulated gain of 10.49 dBi, satisfactory impedance and axial ratio bandwidth, with propagation directed at 29° azimuth. Despite its overall larger size of 297 x 330 x 0.635 mm3, and a focal length of 243 mm, it is still applicable for a 3U CubeSat together with a tape spring based deployment mechanism. Meanwhile, the reflectarray feed is also integrated on the CubeSat with its separate deployment mechanism. The initially designed circularly polarized antenna is also integrated with an artificial magnetic conductor (AMC) plane, which resulted in both gain enhancement and back radiation reduction. Since the initial antenna produces a bidirectional radiation pattern, the AMC plane reduced its back radiation and converting it into a unidirectional pattern. With a dimension of 99 x 99 x 21.485 mm3, the AMC plane increased the gain up to 7.7 dBi with RHCP mode. Besides that, a 19.16 % 10 dB impedance bandwidth and 10.4 % of 3 dB axial ratio bandwidth are achieved at 2.4 GHz. Due to the required gap of 20 mm between antenna and AMC plane, it has been integrated on the CubeSat using a simple spring coil deployment mechanism.
  • Publication
    A comparative analysis of an OCDMA system based on single Photodiode and spectral direct detection schemes
    ( 2014)
    Sarah Ghassan Abdulqader
    The main advantages for using Optical Code Division Multiple Access (OCDMA) are the flexibility of an asynchronous access method, increased security and graceful degradation. Over the last decade, many detection techniques have been proposed for OCDMA, especially for incoherent OCDMA systems. Proper detection selection is very important for good system performance and high network scalability with low bit-error rates (BERs) of less than 10−9. OCDMA systems, however, generally, suffer from multiple access interference (MAI) noise which originates from simultaneous users and severely increases the likelihood of bit errors. To mitigate this limitation, spectral amplitude coding (SAC) OCDMA is used throughout this thesis. The advantage of SAC-OCDMA over conventional OCDMA systems is that, when using appropriate detection techniques, the MAI can be totally suppressed. This either reduces the effect of the MAI or improves the performance even in the presence of MAI. In this thesis, spectral direct detection (SDD) and single-photodiode detection (SPD) techniques based on Modified Double weight (MDW) code, are investigated. The performance analysis of the suggested detection techniques are carried out through simulation experiments using Optisystem software from OptiwaveTM. Moreover, the structure of both detection techniques is based on one photodiode per user compared with other subtraction detection techniques. The comparative analysis shows that the SPD technique is a more capable solution for efficiently restraining interference signals in the optical domain before the signals are converted to the electrical domain. For MDW codes at a data rate of 622 Mbps and a BER of 1×10-10, the results showed that SPD can support more than 60 active users than the SDD technique. Part of the work is also devoted to investigating the feasibility of utilizing different types of optical filters (optical Gaussian, thin film and Fiber Bragg Grating (FBG) filters), and different data formats non-return-to-zero (NRZ) and return-to-zero (RZ). Employing the SPD technique not only provided a BER improvement over SDD, but was used for a large number of users at multiple rates of transmission with cost-effective light sources, and for longer transmission distances.
  • Publication
    A computational fluid dynamic analysis of prolonging survival in the microvascular vein grafting
    ( 2014)
    Muhd Nur Rahman Yahya
    A digital artery disease in the upper extremity is uncommon to happen but the revascularization procedure is still needed. As action taken, the surgical vein bypassing or vein interposition is performed. However, one or more internal diameters of the applied Reverse Saphenous Vein Graft (RSVG) are blocked and severely narrowed due to the irregular geometry formation such as internal diameter mismatched and over the length kink after the revascularization. In previous researches, the irregular geometry formation, the size discrepancy and bent in the vessel caused the abnormal blood flow and initiated the thrombosis. Furthermore, their previous works were also supported by clinical theory. The objective of this study is to investigate the effect of the blood flow on internal diameter mismatched and over the length kink of the RSVG models that relates to their long term survival. A Three-Dimensional Computational Fluid Dynamic (3D CFD) method is employed to investigate the velocity, the pressure gradient and the Wall Shear Stress (WSS) on ideal straight and irregular geometry of the RSVG models. For this research, the pulsatile laminar blood flow demonstrates non-hydraulically flow in irregular geometry of the vein graft models compared to an ideal straight model even in a steady state laminar blood flow test. As a conclusion, the results showed high value in the velocity, the pressure gradient and the WSS in the mismatch problem but low value in the velocity, the pressure gradient and the WSS in the over length kink problem. Any abnormal blood flow behavior will initiate the formation of the thrombosis and reduce the vein graft survival.
  • Publication
    A hybrid input-output based relation test suite generation strategy
    ( 2017)
    Zidan Salem Ali Moussa
    The cause of large enumeration space the systemized sample test data have the active research to meet t-way testing strategies during the previous 20 years Hence that (t) indicates to interaction strength Despite of usefulness, the adoption of existing t-way strategies in the software lacks to be used among engineering community According to a survey on existing t-way strategies, that uniform t-way interactions are dictated whereas variable strength interaction are imposed in some strategies input-output based relationships there also strategies that prescribe interactions Improving the applicability and upgrading the existing t-way strategies adoption there is a requirement for a strategy which is more flexible and is capable to engage all form of possibilities of interaction. The test engineer (as domain experts) should be having the chance to select from various interaction possibilities in this regard, test engineer can be prepared to generate their creative-ambling relying on the testing problem Not until recently a number of strategies have set out to have appeared (e.g. Density, ParaOrder and TVG). However, as t-way test suite generation is considered as NP had problem, no existing strategy can dominance as far as test size of optimality size is concerned. The Motivation of the aforementioned challenge this study will present t-way strategy which is called ITTSG that can support all possibilities of interaction includes input output based relationship further of the t – way test suite has been tested in application.
  • Publication
    A new concurrent, scalable and modular SoC-FPGA-based architecture for HMLP implementation
    ( 2019)
    Lee Yee Ann
    The hybrid multilayered perceptron (HMLP) is a type of artificial neural network (ANN) that was introduced as an enhancement to the multilayered perceptron (MLP). At the same time, the modified recursive prediction error (MRPE) training algorithm was introduced to train the HMLP. Like other ANNs, the HMLP is comprised of many simple processing nodes that operate independently from other nodes. This property of ANN makes the HMLP a concurrent system. On the other hands, the steps and the equations of the MRPE training algorithm makes the MRPE a sequential system. To date, the HMLP was only implemented on two (2) hardware platforms, but both platforms were sequential microcontrollers, which were unable to fully harness the concurrency of the HMLP. In order to implement both HMLP and MRPE on the same device, devices that combines a concurrent system with a sequential system is the best option. SoC FPGA is a type of semiconductor device that consists of a field-programmable gate array (FPGA) and a system-on-chip (SoC) within the same integrated circuit (IC). The FPGA is able to implement a concurrent system, whereas the SoC can execute a sequential algorithm. Therefore, a new SoC-FPGA-based architecture is proposed to implement the concurrent HMLP and the sequential MRPE on the target Cyclone V SoC on-board the DE1-SoC. The concurrent HMLP is implemented on the FPGA, and the sequential MRPE is executed on the SoC of the target Cyclone V SoC. To implement the HMLP and the MRPE on an SoC FPGA, first, a new concurrent, scalable and modular FPGA-based architecture is developed to implement the HMLP on the FPGA. Second, an FPGA-to-SoC interface module is developed for interfacing the HMLP module on FPGA with the SoC. Third, an MRPE program to execute the MRPE training algorithm on SoC is developed. Lastly, the developed SoC-FPGA-based architecture of HMLP and MRPE is implemented on the target Cyclone V SoC for validation. The developed HMLP implemented on FPGA had been validated to be functioning as expected and exhibiting concurrent, scalable and modular characteristics. The FPGA-to-SoC interface module is found to be able to correctly pass data between the FPGA and the SoC of the target Cyclone V SoC device. The HMLP-MRPE system, that combines the HMLP and the FPGA-to-SoC interface modules on FPGA, and the MRPE training algorithm on SoC, is validated by training the HMLP to learn and deduce the outputs of four-input XOR operation. It is found that the HMLP-MRPE system with ni = 4, nh = 6 and no = 1 is able to correctly deduce the output of a four-input XOR operation. Comparing the output latencies of HMLP with ni = 4, nh = 6 and no = 1 between the SoC FPGA implementation to the MATLAB and SoC-only implementations shows that the concurrent HMLP implemented on SoC FPGA at 50MHz clock can compute its output at 60% of the output latency of HMLP implemented on SoC-only at 800MHz. Additionally, the same HMLP at 100MHz clock is able to compute its output at 50% of the output latency of HMLP implemented on MATLAB, which runs on Intel Core i5 processor at 2.5GHz.
  • Publication
    A new flexible cross correlation (FCC) code for optical CDMA systems
    ( 2014)
    Mohd Rashidi Che Beson
    There are tremendous interest in applying code division multiple access (CDMA) techniques to fiber optic communication systems. This technique is one of the multiple access schemes that is becoming popular due to its channel allocation flexibility, asynchronously operation, enhanced privacy, and increased capacity in bursty networks. The performance of optical CDMA (OCDMA) systems are highly dependable on code designed properties. In this thesis, a new Flexible Cross Correlation (FCC) code for OCDMA system is designed, simulated and validated. The FCC code has numerous features such as unfixed cross correlation function with shortest code length, easy to build, and adaptability to accommodate variance number of users and weights. The FCC code is designed based on matrix combinatorial where the tridiagonal code matrix was adopted in developing the algorithm of this FCC code. This research examines the theoretical and simulation aspects in the case of incoherent signal from the broadband light source utilizing AND subtraction detection technique at the receiver side. The results revealed that the FCC code can accommodate 150 users, where FCC code offers 66%, 172%, 650% and 900% improvement as a contrast to 90, 55, 20 and 15 numbers of users for Dynamic Cyclic Shift (DCS), Modified Double Weight (MDW), Modified Frequency Hoping (MFH)and Hadamard codes, respectively, for a permissible bit error rate (BER) of 10−9. The FCC code indicates optical received power Psr of −25 dBm, thus, the detection system is more sensitive via utilizing FCC code. The performance of OCDMA codes were simulated using OptiSystem software from Optiwave TM. The performance of the systems were characterized by referring to the BER, bit rate, optical received power Psr and fiber length. The results shown that the FCC code performs adequately for 45 km as opposed to 21 km for MDW code within bit rate of 155 Mbps and BER of 10−9. In this work, AND subtraction detection technique is employed at the receiver end in order to reduce the receiver complexity, and improve the system performance in terms of distance and number of active users. It has been shown through theoretical and simulation results, the performance of the system with AND subtraction detection technique improved significantly. Based on the validation of theoretical and imulation results employing back-to-back (B2B) transmission, a receiver's power marginal of −36 dB is obtained at a bi rate of 155 Mbps and BER of 10−9 over 10 km fiber length.
  • Publication
    A new fuzzy based diagnosing system for instantaneous processing 12 lead ECG signal
    ( 2014)
    Sameer Kleban Salih
    The Electrocardiogram (ECG) signal reflects the performance of the human heart as an electrical signal. It consists of three main waves (P, QRS complex, and T), and is recorded by an ECG machine in the form of 12 leads which include valuable information about the functional activities of the human heart and cardiovascular system. It is annotated manually by a cardiologist to diagnose cardiac disease, but for a long time ECG recordings were performed to get an effective measure of heart rate variability. The generated ECG data is huge and the probability of wrong analysis or misreading by manual annotation is increased. Therefore, many computerized based techniques have been proposed in literature for analyzing and detecting ECG waves, and at a lower rate for diagnosing cardiac diseases. In this thesis, a new robust intelligent system has been proposed to perform an accurate diagnosis of a high risk cardiac disease named left ventricular hypertrophy (LVH). Four approaches are developed within the proposed ECG system to improve the performance of processing the ECG signal with respect to the existing methods and to discover new system for diagnosing cardiac disease based on the computerized intelligence technique. The first proposed approach is a digital recovery system which addresses the limitation of digital 12 lead ECG data by reconstructing it from the colour scanned image of the ECG printed chart. This approach is implemented by four image processing steps and captures raw ECG data with respect to the baseline which is detected by the same approach. Furthermore, it is reliable for different ECG morphologies and printout charts. The reconstructed data is evaluated qualitatively and quantitatively using some predefined standard features. The analytic results demonstrate the consistency and robustness of this approach to generate 12 lead ECG data with high precision (98%). The second and third approaches are proposed to detect ECG waves and then delineate all time characteristics of these waves. In contrast to the existing methods, both approaches are based on straightforward algorithms that perform instantaneous processing for the ECG signal. As a result, detection operation is executed in a high speed which reaches (4.5s per 650,000 beats) for QRS complex and (2.7s per 225,000 beats) for P&T waves. The based technique in both detection approaches has the advantage of rising falling edge mutation as a base rule for delineating subject. This technique reduces undetected beats and provides accurate detection results exceeding ones in up to date existing methods. The fourth proposed approach is a diagnostic system for LVH cardiac disease based on proposed diagnostic criterion. In contrast to the conventional LVH diagnostic criteria, the decision in the proposed criterion is computed by three logical expressions; two of which are determined by a combination of classic criteria, whereas the third is obtained by eight ECG voltages and takes two different levels for each gender. These expressions are represented by the membership functions in the proposed design of the fuzzy inference system. The proposed diagnosing system is validated by fifty ECG records, in which the validation results score were perfect (100%) in terms of sensitivity, specificity, and accuracy, while the best diagnosing accuracy achieved by traditional diagnostic criteria does not exceed 90%.
  • Publication
    A new three-dimensional code for OCDMA system
    ( 2016)
    Rasim Azeez Kadhim
    Many codes have been proposed for incoherent OCDMA based on one-dimensional (1-D), two-dimensional (2-D), and three-dimensional (3-D) by exploiting one or more resources simultaneously. The 3-D Perfect Difference (3-D PD) code has been proposed for spectral/time/spatial OCDMA system in order to increase the number of users by using shorter code lengths. But, the complexity of the system, especially the decoder, is increased. In this research, a new 3-D code namely, Three-Dimensional Diluted Perfect Difference/ Multi Diagonal (3-D DPD/MD) code is proposed for the incoherent OCDMA system, to completely cancel the Multi Access Interference (MAI), mitigate the Phase Induced Intensity Noise (PIIN), accommodate a large number of simultaneous users and reduce the complexity of the 3-D system decoder. The 3-D DPD/MD code has been developed based on the DPD and MD codes. The study of the proposed code, included the mathematical derivation of the performance equations in terms of Signal to Noise Ratio (SNR) and Bit Error Rate (BER) under the effect of receiver noises, and the validation by using optical simulation software. The system performance was investigated under the effect of data rate, distance, received power, and the photodetector type. Theoretical results showed that the 3-D DPD/MD code system achieved better performance than the 3-D PD, 2-D DPD, and 2-D PD codes of similar total users where a larger number of simultaneous users can be accommodated using the same data rate and received power. At BER of 10-9, it could support 1020 simultaneous users at 0.622 Gbps and -7 dBm compared with 660, 570 and 490 users of 3-D PD, 2-D DPD and 2-D PD codes, respectively, where the improvement factors were 54%, 78% and 108%. Also, the proposed code provided better performance than the others at 1.25 Gbps. Moreover, the 3-D DPD/MD code provided 600 active users at lower received power of -15 dBm with data rate of 0.622 Gbps. Consequently, the spectral efficiency based on the 3-D DPD/MD code was enhanced by more than 27%. In addition to that, the using of the 3-D DPD/MD code reduced the decoder complexity by more than 50% when compared with the 3-D PD code. On the other hand, the simulation results validated the proposed code to support the service differentiation in optical networks via simulation modeling. As a result, a high spectral efficiency, low system complexity, and a large number of simultaneous users can be accommodated by adopting the proposed code in the OCDMA networks.
  • Publication
    A new wireless sensor network wave propagation model based on Zigbee protocol for protected mango greenhouse environment
    ( 2017)
    Auda Raheemah Odhaib
    The wireless sensor network (WSN) is the promising technology and it is widely used for monitoring and controlling the environmental conditions of precision agriculture. The deployment of the WSN nodes in real environments faces hard challenges of proper communication links and network coverage especially in the case of deployment of wireless nodes near the ground and the existence of dense vegetation which may impair the propagating signals. Modeling of wireless communication channel is important to achieve a successful implementation of WSN system in agricultural environment. In WSN, accurate propagation path loss models help for realization appropriate evaluation of the WSN performance, achieving more reliable communication, improving the power efficiency of the network nodes and decreasing the overall cost of the wireless network. There are many propagation path loss models used for modeling wireless communication channels, but most of them might not be suitable for the WSN applications due to propagation medium and the IEEE 802.15.4 standard. In this research, the WSN signal propagation path losses inside the mango greenhouse environment are investigated by using WSN based on the ZigBee standards. Various empirical measurements were conducted to examine the effect of each part of a tree on path loss with different transceivers’ heights to select the best antenna heights that adopted in all experiments for deriving the new path loss model. Indeed, a new propagation path loss model for greenhouse environment (Greenhouse Propagation Path Loss Model - GHPLM) is derived based on a regression technique. This new model is used for computing the total propagation path losses and for deployment the wireless sensor nodes in the real field based on the maximum separation distance measurements. The outcomes from this work proved that the antenna heights and the vegetation depth are the two most important factors in channel modeling. The empirical results emphasize that the Plane Earth (PE) model is inaccurate for predicting path loss in real environments due to it is based on simplistic approaches and considered to be very optimistic in real propagation scenarios as the case in mango greenhouse environment. Thus, the combination of this model with the vegetation path loss model contribute more convincing results and can best describe the behavior of actual WSN systems when deployed in a real environment. The empirical results proved that the GHPLM model is the best candidate compared to other existing empirical propagation path loss models. The Mean Absolute Percentage Error (MAPE) that measured the difference between the actual and prediction path loss was 3.96% for the new GHPLM model compared to other vegetation path losses which were 44.55%, 41.07%, 31.82% and 15.48% for Weissberger, ITU-R, FITU-R and COST235 models respectively.
  • Publication
    A new wireless sensor networks deployment strategy using hybrid particle swarm optimization
    ( 2019)
    Ali Noori Kareem
    Sensor Deployment (SN) is one of the major challenges in wireless sensor network architectural. One of the most fundamental issues in wireless sensor deployment is to find a trade-off between two conflicting network objectives; Packet Delivery Ratio (PDR) and lifetime, under certain coverage and connectivity constraint. Although the approach of meta-heuristic searching optimization has been commonly applied, it has failed in addressing several issues related to multiple objectives and intricate optimization surface. However, the multi-objective nature of this problem and the complicated optimization surface requires developing customizable multi-objective meta-heuristic searching optimization. This thesis proposes a Lagged Multi-Objective Jumping Particle Swarm Optimization (LMOJPSO) approach that aims to find the Pareto front that maximizes the packet delivery ratio and minimizes the sensor energy consumption for prolonging network lifetime. The proposed LMOJPSO framework for improving the performance of the meta-heuristic search optimization process, is done by combining two different searching techniques. The first optimization technique carries out its searches with the help of Extreme Learning Machine (ELM), whereas the second search optimization uses a wireless sensor network simulator. In this thesis, the proposed method is examined in a given wireless sensor network test instances and the evaluation of its performance is carried out by using a wireless sensor networks performance metric. The results indicated that the proposed model is superior to the Non-dominated Sorting Genetic Algorithm (NSGA-II).
  • Publication
    A non-invasive ultra-wide band based system using artificial intelligence to determine blood glucose level
    ( 2017)
    Md Shawkat Ali
    Diabetes is a serious health concern and declared as global epidemic by WHO due to its rapidly increasing incidence. It is a major cause of mortality worldwide. For a diabetic patient maintenance of blood glucose level within the physiological range is essential to lead a healthy life. The frequent monitoring of blood glucose is an important part of diabetic management specially for type-1 diabetes. A laboratory test or self-test with a small device uses a blood sample collected from a body part with a needle. In extreme cases a diabetic patient needs to undergo this painful process several times a day. To reduce this suffering, a non-invasive (without any blood sample) and patient friendly way of measurement is crucial. Unique advantageous features of UWB technology has demonstrated the widely use of biomedical applications, specially for early breast cancer detection. In the field of exploring potential non-invasive solutions to diabetes detection one promising alternative can be UWB based system using artificial intelligence technique. This relies on variation of dielectric properties (permittivity and conductivity) of target tissues or cells in a given frequency. Initially the experimental setup was prepared with different types of homemade antennas to select the appropriate antenna type, perfect measurable body place, and to confirm the proof of concept. In integrated system a rectangular patch antenna was fixed with a transceiver to generate 4.3 GHz frequency and pass through the earlobe. Received discriminated scattered signal was processed and discrete values were reduced to use as input of artificial neural network (ANN). Number of experiment was conducted to construct an optimal ANN module where actual blood glucose was used as target. The final network output was used to obtain the blood glucose reading from a given scattered signal value.
  • Publication
    A novel 2-D wavelength-time Optical Code Division Multiple Access (OCDMA) code for high-performance system
    ( 2013)
    Amir Razif Arief Jamil Abdullah
    The explosive growth of bandwidth demand, together with advance in latest communication services and emerging applications has inspired huge interest in application of code division multiple access (CDMA) technique in optical network. The major interference factor in optical CDMA (OCDMA) is to overcome the multiple access interference (MAI) noise which induces the occurrence of bit error rate. Ideal code property with minimum cross-correlation will mitigate MAI, reduce phase induced intensity noise (PIIN) and expand code scalability. Part of the work devotes to analyzing how OCDMA can suit into the future generation of optical network. In this thesis the new incoherent two-dimensional (2-D) modified double weight (MDW) OCDMA wavelength-time is proposed and demonstrated. The thesis begins with an explicit construction of incoherent 2-D MDW OCDMA system with allocation of wavelength and time dimensions resources to aspire performance goals and designed parameters. A novel 2-D MDW OCDMA uses balance detection for mitigating MAI. The code is theoretically analyzed and simulated for the performance. The good property of cross-correlation results in optimum PIIN suppression in comparison to the other codes such as 2-D PDC and 2-D MQC. This is reflected through high SNR value or low bit error rate (BER) as the cardinality increases. The comparison outcome of the proposed 2-D MDW code with 2-D PDC, 2-D MQC and 1-D MDW code indicates substantial performance improvements in cardinality, BER, bit rate and distance. The proposed code achieves high scalability; below 10-9 BER error floor the code cardinality reaches 189 simultaneous numbers of users which is double the 2-D PDC performance. The lowest effective transmitted power (Psr) for minimum optical transmission requirement for smallest number of users is achieved at -22.5 dBm. The combination of wavelength and time-chip can be further enhanced the overall system performance. The proposed code has successfully mitigating MAI by the balance detection technique. The 2-D MDW OCDMA simulation model is developed to validate the realization of the code for BER, bit rate and distance performance. In short the 2-D MDW OCDMA code successfully suppresses PIIN and mitigating MAI which result in high cardinality, reduce Psr, high bit rate and distance.
  • Publication
    A novel approach using optical fringe analysis for breast Carcinoma detection
    ( 2017)
    Rajendaran Vairavan
    Breast carcinoma is one of the primary cancers diagnosed among woman with 25.1 % accounted of all cancers in women. Recognized methods for breast carcinoma detection and diagnosis include breast self examination (BSE), physical examination, invasive methods such as fine needle aspiration (FNA) and biopsy and non-invasive breast imaging methods such as mammography, ultrasound and magnetic resonance imaging (MRI). However, BSE, CBE, mammography, ultrasound and MRI are not entirely noninvasive as the methods somehow requires physical touches to the breast. Based on the reported previous works, the feasibility of using an optical method is evident as a full non contact and non invasive method, and there is room for vast improvement in using optical methods for early breast carcinoma detection based on surface analysis. Fringe projection techniques are emerging as non-contact tool in optical metrology with applications ranging from 3D Micro-electromechanical systems (MEMS) component measurement, accurate flatness measurement, vibration analysis and biomedical applications for assessment of complex three-dimensional human form. Despite the vast applications in the biomedical field, application of fringe projection in breast carcinoma detection and assessment is notably minimal. Thus, in this work, the usage of a fringe projection rig based on phase shift technique for non-invasive surface metrology analysis of the breast as an adjunct tool for early breast carcinoma detection was done. The fringe projection rig was utilized to analyze the surface changes of the breast due to the presence of breast lump within the breast.
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  • Publication
    A novel energy efficient of network on-chip (NoC) architecture for system on-chip (SoC)
    ( 2019)
    Ng Yen Phing
    As the number of intellectual property (IP) integrated into a chip increases, this can present serious challenges to achieving the performance and power needed for satisfying the constraint on future chip. The addition of the intelligent networking on the chip adds to the power consumption of network-on-chip (NoC). Thus, system-on-chip (SoCs) is required to be capable of delivering high performance and consuming low power, of the interconnection infrastructure to large number of cores. This research aims to focus on proposing ways to use current available network interconnection modal to provide NoC of better performance, smaller total area, and higher power efficiency, by optimizing interconnection architecture. In order to solve the problem encountered with large scale network, a design of power saving clustering, segmentation-connectivity, and partition technique is useful for multiple homogeneous applications which need to be executed in parallel and mapped on a large network. This technique reduces the number of link and lowers the average distance of a network, which help in achieving low power consumption. Topology can be clustering, segmenting, and partitioning the cores of similar characteristic into the same group. The nodes in the same group are highly connected, while the nodes in different group are sparsely connected. The objective of research is to search for the most power efficient and performance aware topologies based on clustering, segmentation-connectivity, and partition strategy. At the same time, this research minimizes performance penalty by applying sleep mode, standby mode, and hibernation mode based on different runtime application. This is crucial as different application has different requirement of logical cluster, segment, and partition size. By efficiently handling the connection of clustering, segmentation-connectivity, and partition technique, the experimental results show that these techniques achieve up to 9.39% ~ 71.89% power saving, up to 0.97% ~ 53.59% area saving; reduce average network latency up to 9.81% ~ 76.26%; and up to 6.65% ~ 78.96% power latency product (PLP) saving as compared to traditional topology. In the end, the results show that turning ‘off’ the nodes of the cluster, segment, and partition topologies reduce latency and power consumption. The results also indicate the importance of power and latency co-optimization in NoC design.
  • Publication
    A novel zero cross correlation code for optical code division multiple access system
    ( 2012)
    Anuar Mat Safar
    Optical Code Division Multiple Access (OCDMA) techniques have shown outstanding capabilities in sharing multiple users simultaneously in access network. The purpose of this study was to develop a new spectral amplitude coding (SAC) in OCDMA code. In particular, we tried to minimize multiple access interference (MAI), consequently diminish the phase induced intensity noise (PIIN) by using this new code with the main characteristic of zero cross correlation in its property. This code was investigated and analyzed for its performance in the network system. Another aim was to find out the components and parameters used in order to optimize the performance of the code. Finally, the analysis was validated by comparing theoretical studies with the simulation results. The method of combinatorial matrix was applied in developing this zero cross correlation (ZCC) code. By using SAC incoherent OCDMA techniques, we were able to mitigate the PIIN effect in the system performance. The study of system performance methodology in ZCC code was conducted and used to generate the mathematical derivation for the code performance theoretically.The simulation was conducted with optimization of the parameters involved to obtain the best performance in the system. The validation of the theoretical results was confirmed through this simulation analysis. The great contribution of ZCC code was that there was no overlapping of bit ‘1’ among users and absolutely orthogonal for any number of users and weights. The code structure was very flexible especially in changing code parameter such as the number of users and the number of weight. The code demonstrated an excellence in signal security due to the random code structure. Our performance analysis showed ZCC code has a better performance compared to other codes in the same class of SAC. It could also accommodate a higher number of users simultaneously. This system could support 110 users simultaneously with a permissible bit error rate of 10-9. Power required was lower at the photo detector which means the detection system required less power by applying this code. Direct detection technique used in the ZCC coding system reduced the number of filters, thus led to less system cost. The results showed that employing ZCC coding technique achieved higher bit rates up to 10 Gigabits per second compared to other coding techniques. The principal conclusion was that by the invention of the new ZCC code, it contributed to the solution of many issues in OCDMA such as reduction of MAI, increased the number of users accommodated, increased effective power at the detector, higher bit rates being transmitted, enhanced security and reduced the complexity by using a direct detection technique.
  • Publication
    A resilient cognitive detection with automated channel selection for enhanced channel management in wireless local area network
    ( 2017)
    Mohammad Nayeem Morshed
    Spectrum saturation problem is a critical issue now a day due to huge number of users with wireless capable devices joined the network every day, but the spectrum resources are limited. To overcome this issue, cognitive radio (CR) technology was first proposed in year of 1999. The main objective of CR is to use licensed primary users’ (PUs’) spectrum by secondary users (SUs) without interfering the PUs. To detect PU channels, spectrum detection technique plays a major role to find the presence or absence of PUs to avoid interference. To protect licensed PUs’ from unwanted interference, the channel detection scheme is required to perform well in low signal to noise ratio (SNR) environments. Most of the work in the literature were performed based on computer based simulations and very few with experimental workflow, but they have used heavy laboratory instruments or stationary sensors for channel detection. Considering this issue, this thesis presents a method for real-time channel detection technique in a wireless local area network (WLAN) based CR network using Android based smartphones/tablet PCs. Also, designed an automatic channel selection (ACS) algorithm, which is practically experimented with an adaptive threshold determination technique with the 2.4 GHz WLAN. The algorithm is designed to work especially with Android based smartphones and tablets. Energy detection method with free space path loss (FSPL) environment is considered throughout the experiment for available PU channel detection.