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Visible Light Communication (VLC) is a novel optical wireless communication technology which uses Light Emitting Diodes (LEDs) and Photodiodes for coherent detection and very-high-data rate data communication system. The stringent Line of Sight (LoS) requirement in VLC makes it very suitable for Indoor Positioning System (IPS), to be used for autonomous and smart city infrastructure. The current work aims to implement a real time IPS system using VLC link in Network Simulator (NS-3). The VLC module is implemented by modelling real-time attributes of LEDs, optical channel, and the photodiodes. The localization is carried out using trilateration schemes which measures the Received Signal Strength Indication (RSSI) and the Time Difference of Arrival (TDoA) for position estimation of the target. The project is further extended to obtain a comparative analysis between VLC link and other existing technology, Wi-Fi, as far as positioning accuracy and other important performance metrics are concerned. The simulation results show significant improvement for the VLC link over the Wi-Fi link specially for the TDoA scheme accompanied by increasing number of beacon nodes.

Visible Light Communication (VLC) is a novel optical wireless communication technology which uses Light Emitting Diodes (LEDs) and Photodiodes for coherent detection and very-high-data rate data communication system. The stringent Line of Sight (LoS) requirement in VLC makes it very suitable for Indoor Positioning System (IPS), to be used for autonomous and smart city infrastructure. The current work aims to implement a real time IPS system using VLC link in Network Simulator (NS-3). The VLC module is implemented by modelling real-time attributes of LEDs, optical channel, and the photodiodes. The localization is carried out using trilateration scheme which measures received signal strength interference (RSSI) for position estimation of the target. Furthermore, a comparison is carried out between VLC link and other existing technology, Wi-Fi, as far as positioning accuracy and other important performance metrics are concerned. The simulation results show significant improvement for the VLC link over the Wi-Fi link.

Visible Light Communication (VLC) is an emerging wireless optical technology in the field of data communication. The VLC systems have a wide light spectrum, which provides a high data rate and low Peak to Average Power Ratio (PAPR). One of the major issues in VLC systems is interference which is caused by daylight and other illumination sources. The other issue in VLC systems is that the transmission side provides data as complex values which causes transmission related issues and is hard to read at the receiver side due to a lot of channel noise. To solve these issues, we propose the hybrid approach of Pulse Width Modulation (PWM) and Orthogonal Frequency Division Multiplexing (OFDM) with the Code Division Multiple Access (CDMA). The CDMA is employed for multiplexing the multi-user data for transmission to accommodate a large number of users and avoid inter-user interference. The line of sight (LOS) and non-line of sight (NLoS) components of the optical channel are simulated in MATLAB. Finally, the system is also designed physically using NI modules for the real-time environment. The results show that the VLC systems with PWM-OFDM perform better as compared to simple OFDM systems.

Three-dimensional (3D) modeling of objects play an important role in quality assurance, re-engineering of an object, and mapping of interior design for quality measurements. Hence, this field proves to be one of the hot research topics in the field of robotics. Although, using laser scanner is the most common method for 3D point cloud, the camera-based methods are also introduced in this field. In this paper, we propose and analyze two methods for making 3D point cloud for any given object. First one is camera-based 3D point cloud using structure from motion technique and secondly the laser scanner-based 3D point cloud. The result shows that camera-based 3D point cloud method produced dense point cloud but prone to outliers, whereas the laser scanner method is robust. It should also be noted that the camera is multiple times cost effective than laser scanner.

Perceptual Image quality assessment is a challenging problem especially in the absence of reference information. No-reference quality assessment is required for a number of applications such as quality assessment of image acquisition, enhancement and communication scenarios. Conventionally the problem is addressed by extracting natural scene statistics but recent development of deep learning has paved the way of deep learning based methods. Convolutional Neural Networks (CNN) has shown surprising performance for the task of visual classification but they have some inherent limitations such as high computational requirements, limitations of scalability and model variance. Ensemble learning methods are used to improve the generalization performance of machine learning methods but their application to CNN is limited due to their already high computational requirements. We have proposed an approach to train a single CNN model with a learning rate scheduler and save its training states at regular intervals. These saved model states are treated as base models and some of them are selected to construct ensemble with weighted averaging. The proposed methods has provided promising results and indicate its utility for training of advanced architectures for ensemble learning.

Non-orthogonal multiple access (NOMA) is a promising multiple access technique, proposed in literature for the fifth generation (5G) mobile networks. The NOMA system model consists of the conventional orthogonal frequency division multiplexing (OFDM), as a pulse shaping technique in conjunction with a variable power domain for various users, allocated in proportion to each user’s channel gain. OFDM technique based on wavelet filter banks, namely wavelet OFDM (WOFDM) has been utilized in digital communication to improve the system robustness to noise and adjacent channel interference, and is therefore anticipated to be adopted for the NOMA technique. WOFDM in NOMA (WNOMA) outperforms OFDM-based conventional NOMA (CNOMA) with reference to interference mitigation, bandwidth efficiency, spectral confinement, and multi-user capacity. Most of the fourth generation (4G) networks are based on OFDM and its variants. Therefore, in this paper, keeping in view the interoperability with the 4G networks and the latency requirements in 5G, a dual physical layer based on conventional OFDM and WOFDM as pulse shaping methods, is proposed for the NOMA transceiver. Performance of WNOMA and CNOMA is analyzed for bit error rate in the presence of channel impairments including additive noise and IQ imbalance and multiuser capacity is also computed. Comparison of various parameters indicates the advantage of adopting WNOMA over its conventional counterpart for relatively poor channel conditions.

The hybrid power line communication (PLC) and visible light communication (VLC) systems can be effectively utilized for the efficient design of 5G communication setup. However, each of these integrated communication media is not primarily meant for the specific purpose of data communication, as PLC and VLC have historically served to transfer electrical energy transfer and light, respectively. With the advent of high flickering rate light emitting diodes and efficient multiplexing/modulation schemes, both technologies are observed as potential data communication carriers. Therefore, this paper presents a novel approach for modifying the modulation technique in accordance with the channel requirements of a hybrid PLC-VLC-based 5G communication systems. We provide a thorough analysis of the research work done to co-use these two technologies for data communication, suggest some exciting applications of integrated PLC-VLC systems and propose discrete wavelet transform (DWT)-based orthogonal frequency division multiplexing (OFDM) to tune the physical parameters as per the hybrid channel characteristics. Theoretical and simulation bit-error-rate results exhibit that DWT-OFDM outperforms an OFDM-based PLC-VLC system. The proposed hybrid system can be used to design smart buildings where indoor/intra-building connectivity is maintained by VLC whereas inter-building networking based on PLC communication.

This paper aims to improve the performance of DC motor drive system by utilizing a fractional-order proportional-integral (FOPI) speed regulator. Available tuning guidelines to design the FOPI speed regulator for a DC motor drive system are also presented. Two closed loop speed control strategies, namely DC motor armature voltage control and armature current control, are proposed for comparative investigation. Numerical simulations and quantitative analysis are performed to evaluate the efficacy of FOPI speed regulator-based DC motor drive system. Simulation results show that the FOPI speed regulator-based voltage and current control strategies are robust against external disturbances and are effective for DC motor drive system.

Continuous power supply is one of the major concern in modern world and for this purpose protection schemes must be efficient enough to overcome faults with minimum time. This paper presents the design of electromechanical and microcontroller (Arduino) based relay as an educational lab trainer to compare the behavior of both relays in over current protection of radial feeder. The proposed trainer introduces the use of both electromechanical and microcontroller based relays in a single panel in such a way that the system could be switched to either electromechanical or microcontroller based relay setup. It is designed for protection of two sections so that the concept of primary and secondary protection is observed. Microcontroller based relay setup is coded with IDMT characteristics and requires the values of PSM and TMS for the calculation of operational time of relay to clear the fault. This trainer also displays the magnitude of fault current as well as operational time of relay required to clear the fault. The fault is incorporated to the system by the insertion of low resistance path which leads to additional flow of current. Simulations are carried on Proteus and the hardware result shows that microcontroller based relays are fast in operation having less time of operation, more efficient and have very low cost as compared to conventional electromechanical relays. This trainer's idea could be implemented in engineering universities as a compulsory component for electrical power students.

Biometric authentication is a process that validates the user’s identity by measuring his intrinsic characteristics. This process is used to cater for the security-related issues. There are many techniques of biometric identification, e.g., face recognition, fingerprint identification, retina and iris scanning. Face recognition is a simplest and efficient technique. It can be implemented through different methods, e.g., Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), Discrete Cosine Transform (DCT) and Independent Component Analysis (ICA). PCA is the most practical method because of its accuracy, time limitations and process speed. This paper analyzes the performance of PCA using different averaging techniques and proposes useful recommendations that, once incorporated, will improve the accuracy and computational complexity of the algorithm under certain constraints. The proposed system has been programmed in MATLAB and tested on Olivetti Research Laboratory (ORL) database of faces. The performance of the modified PCA has been compared with the conventional PCA and simulation results have been discussed in terms of accuracy and complexity analysis. The proposed system with recommended changes has also been evaluated through hardware implementation, discussed at the end of this paper.

Load frequency control (LFC), is an effective methodology to regulate the frequency but time delays jeopardize the stability of the power system. With the expansion of the power grid and introduction of renewable sources, the duration of these time delays is predicted to grow. This paper explores the performance of different controllers from literature for frequency restoration in a power system. The tuning guidelines for controllers, frequency deviation response, and delay margin analysis are presented in this work. The simulation results demonstrate that the controllers tuned while considering time delays significantly outperform controllers tuned while ignoring time delays.

This paper investigates the effect of speed regulators on the battery bank voltage and current profiles for a prototype electric vehicle traction system. A 400 V, 6.6 Ah Li-Ion battery bank is established to power an indirect field oriented induction motor drive system. The performance of integer-order PI and fractional-order PI controllers is investigated while the electric vehicle traction system executes the urban and extra urban drive cycles. Also, the controllers' effect on the battery bank is examined under the sudden load disturbance. The experimental results reveal that the nonlinear fractional order PI controller provides better speed tracking with lesser control effort. The reduced control effort of FO-PI controller draws lesser current from the battery thus improving the battery voltage profile and efficiency.

With the exponential hike in cyber threats, organizations are now striving for better data mining techniques in order to analyze security logs received from their IT infrastructures to ensure effective and automated cyber threat detection. Machine Learning (ML) based analytics for security machine data is the next emerging trend in cyber security, aimed at mining security data to uncover advanced targeted cyber threats actors and minimizing the operational overheads of maintaining static correlation rules. However, selection of optimal machine learning algorithm for security log analytics still remains an impeding factor against the success of data science in cyber security due to the risk of large number of false-positive detections, especially in the case of large-scale or global Security Operations Center (SOC) environments. This fact brings a dire need for an efficient machine learning based cyber threat detection model, capable of minimizing the false detection rates. In this paper, we are proposing optimal machine learning algorithms with their implementation framework based on analytical and empirical evaluations of gathered results, while using various prediction, classification and forecasting algorithms.

The quality of a finished MESFET is assessed by evaluating its DC and AC characteristics, whilst the target characteristics can be achieved by optimizing the device parameters prior to its fabrication. In this research the I - V and R.F characteristics of submicron SiC MESFET are simulated. In order to achieve optimum values of simulated intrinsic parameters, an objective function based on experimental data for both phase and magnitude is defined. The device intrinsic small signal parameters are then evaluated by using the simulated data. By using particle swarm optimization, different gains of the device and insertion loss are also taken into account which helped in formulating a good agreement between simulated and experimental data.

This paper explores the effects of optimization following the adaptive parameters estimation (APE) on Li-ion battery parameter estimates. The universal adaptive stabilizer (UAS) based APE method has been proven to be less expensive both computationally and in terms of required experimental effort. However, the APE method requires the user to make an appropriate initial guess of upper, lower bounds and their respective confidence levels for each parameter. Making such initial guesses are not trivial, and the effects of bad initial guesses are proposed to be mitigated by adopting a well-known particle swarm optimization (PSO) technique to further optimize parameters estimates, after APE terminates. The estimates obtained from the APE method narrow the search interval and thus reduce the computational effort of the PSO technique to identify the optimum estimates of Li-ion battery parameters. In this work, the APE followed by PSO based scheme is developed and validated through simulation results on a well known, and experimentally validated Li-ion battery model.

This paper presents a robust state space sinusoidal reference tracking controller that is able to estimate the overall friction faced by the platform attached to a linear voice coil motor. The system proposed is able to estimate overall friction faced by the platform attached and is also able to compensate for it. This paper discusses the various simple model of friction found in literature and uses them as a basis for the importance of friction compensation. Further analysis is provided on the formation of the sinusoidal reference tracking controller which is followed by the overall augmented system. A practical implementation of the systems is also provided which is used to obtain the results for the friction estimation. The results found from the implementation of the system are compared to the free-fall method used to estimate the Coulomb and viscous friction parameters.

In this paper, we propose a novel visible light communication (VLC) based indoor positioning system (IPS) for Internet-of-Things (IoT) applications. In such systems, to minimize the harmful flickering effects due to intensity modulation of LED lamps, our proposed design only requires a single LED ceiling lamp and multiple photodiodes (PDs) at the receiver. We propose an ON/OFF switching frequency pattern of our single LED ceiling lamp that allows the use of time difference of arrival (TDOA) based positioning algorithm. The localization accuracy achieved by our proposed design is very high and the error in the estimated position of a receiver is only few millimeters (mm). This performance is comparable to the IPS systems that rely on multiple LED lamps. We also consider different arrangements of photodiodes at the receiver. Simulation results reveal that in terms of localization accuracy, circular arrangement of PDs outperforms all other considered configurations.

This paper proposes a noble scheme employing Fuzzy logic(FL) algorithm for the efficient and reliable operation of an adaptive Single-Phase Auto Recloser (ASPAR). The detection and diagnosis of faults been carried through Distance Measuring Relay(DMR). The proposed system involves fuzzy logic, logic gates, timers to accurately sort out the type of fault based on angular difference of the phases. The unspecified tripping signals of the traditional protection relay are recognized by the blocking signals of the fuzzy logic based fault classifier to yield a trained signal to auto re-closure scheme. The designed system is simulated using PROTEUS. The simulation results ensure the efficient working of fuzzy logic algorithm by explicit fault detection.

Economic load dispatch is a non-linear, complex and constrained optimization problem. In this paper a bio inspired meta-heuristic optimization technique namely novel bat algorithm is proposed for solving economic load dispatch problem. The results of three unit thermal system without losses and six units thermal system inclusive of losses had shown that novel bat algorithm had outperformed Lagrange relaxation, lambda iteration method, genetic algorithm, particle swarm optimization, pattern search algorithm, modified bacterial foraging algorithm, intelligent water drop algorithm and traditional bat algorithm in term of the best global optimum solution and fastest convergence.

Visible Light Communication (VLC) is an emerging technology to leverage the heavy data loads on over traditional RF technologies. It can be used for dual purposes, i.e., data transmission in addition with illumination. In this paper, performance of Non Line of Sight (NLOS) VLC channel has been investigated under different equalization schemes. The objective has been to explore an efficient equalization this is both performance-efficient and less complex. In this regard, Fractionally spaced equalization (FSE) has been employed for indoor VLC channel and compared with other existing equalization schemes. The simulation results show that the slope of the curve of FSE bit error rate (BER) is parallel to that of Maximum Likelihood (ML) equalizer with much less complexity. Moreover, FSE outperforms all other existing equalizers.

Due to copyright restrictions, the access to the full text of this article is only available via subscription. Axial fans are often used in cooling electronic enclosures where low noise levels are highly demanded. Therefore, methods for predicting the noise emitted by an application including single or multiple fans are desirable to improve, stimulate and reduce the cost of low-noise design. The prediction of sound generated from fluid flow has been difficult due to the non-linear form of the governing equations, however, recent developments in computational fluid dynamics (CFD) and computational acoustics allow us to determine sound pressure levels (SPL) in a fluid flow. In this study, time dependent flow field produced by an axial fan is computed via Large Eddy Simulations (LES), and the consequent sound pressure map is determined using the Ffowcs Williams-Hawkings (FW-H) model. Since an axial fan is a complex source of sound, for engineering design purposes, simplifications are needed when modelling its acoustic characteristics, therefore, the sound radiation of an axial fan in free space is examined by expanding the generated sound pressure field into spherical harmonics. In addition, acoustic measurements are carried out in a semi-anechoic chamber to validate the aforementioned computational models and make necessary comparisons. Comparison of the numerical results against the experimental data shows that, despite some discrepancies, the former is able to capture the trends observed in the measurements. Aselsan ; SSM (undersecretary of Turkish ministry of defense) ; Istanbul Development Agency

With the emergence of Light Emitting Diodes (LEDs), Visible Light Communication (VLC) has become an emerging technology for short range data communication. In this paper, a complete VLC software defined radio (SDR) transceiver is implemented on National Instrument (NI) cDAQ modules programmed in LabVIEW/MATLAB. The transceiver design mainly consists of VLC transmitter, receiver and interfacing of cDAQ modules. The major blocks of VLC transmitter comprise Optical Code Division Multiple Access (OCDMA) to improve the signal quality. The novelty in the designed prototype is that it is capable of compensating errors over a distance of 1 meter in a brightly lit room. Over and above physical system, simulation programs are also developed to investigate the impact of line-ofsight (LOS) VLC channel. In order to investigate VLC channel, Bit-Error-Rate (BER) performance is carried out to compare the proposed system with traditional VLC system.