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The impact of social media technologies on adult learning
No full textTechnology and social media have presented significant tools for adult learners to learn and advance continually. Fast technological advancements have enabled development of technologies used for learning. Expansion of various tools has given professors ,educaters,trainers,instructers, many alternatives towards the implementation of the technology supported learning. The use of social media can improve adult learning outcomes and academic accomplishment. Social media is increasingly proven to be beneficial in adult learning and has a huge potential for adult education. this paper sheds some lights on benefits of social media for adult learners ,this is incorporated through the review of previous work and some barriers that encounters social media for learning purposes. Also some social media models are reviewed to show the growth and effect of social media in adult learning context, and suggestions and recommendations are provided
Testing of a Solar-PV/Wind operated AC-DC Microgrid with LabVIEW Controller
No full textThis paper discusses about a LabVIEW based controller for the hybrid renewable energy system operated AC-DC microgrid with the major objectives of: i) predicting the power generation potential of the solar–PV and wind generators ii) effective power management iii) load scheduling based on the available power with the renewable sources and iv) grid/islanding mode of operation of the microgrid. In order topredict the output power of wind generator and Solar-PV system, an artificial neural network is developed.The laboratory-scale model of three phase, 400 V, 10 kVA microgrid structure is developed at National Institute of Technology Calicut, India. The developed LabVIEW based controller has been tested successfully for a real-time load and source in the laboratory environment. Test results show that the designed controller is effectively managing the output powerof the primary energy sources under different scenarios
Modeling and Nonlinear Control of a Wind Turbine System Based on a Permanent Magnet Synchronous Generator Connected to the Three-phase Network
No full textThis article presents nonlinear control of wind conversion chain connected to the grid based on a permanent magnet synchronous generator. The control objectives are threefold; i) forcing the generator speed to track a varying reference signal in order to extract the maximum power at different wind speed (MPPT); ii) regulating the rectifier output capacitor voltage; iii) reducing the harmonic and reactive currents injected in the grid. This means that the inverter output current must be sinusoidal and in phase with the AC supply voltage (PFC). To this end, a nonlinear state-feedback control is developed, based on the average nonlinear model of the whole controlled system. This control strategy involves backstepping approach, Lyapunov stability and other tools from theory of linear systems. The proposed state-feedback control strategy is tested by numerical simulation which shows that the developed controller reaches its objective
Modeling and Simulation of Grid Connected Hybrid Energy System and its Fault Analysis
No full textThis paper represents a hybrid energy system (HES) consisting of photovoltaic (PV), Solid Oxide Fuel Cell (SOFC), electrolyzer system and a storage tank. In this proposed system a fuel cell controller is used where a PID controller is utilized to control the flow of hydrogen (H2) through the valve to the SOFC to fulfill the load requirement. In this model a supervisory controller is used to regulate the whole system according to load requirement. So, when PV power is more than load requirement, then PV power fulfill the required load demand as well as the extra power of PV is utilized to generate the hydrogen (H2) by the help of electrolyzer, further this hydrogen is used as a fuel of SOFC. Also in this proposed model different types of faults are considered and verified their effect on the load as well as in distribution network. The computer simulations are done for the purpose technology and verified its effectiveness. Hence the appropriate results are obtained
Implementation of Cascaded based Reversing Voltage Multilevel Inverter using Multi Carrier Modulation Strategies
No full textIn this paper, a cascaded based reversing voltage (CBRV) multilevel inverter structure is proposed inorder to compensate the major drawbacks in the conventional multilevel inverters. The proposed topology requires less number of components, less carrier signals and gate drives when compared to existing multilevel inverters particularly at higher levels. Therefore, the complexity and overall cost are greatly reduced particularly for higher output voltage levels. This paper also presents the most relevant control and modulation methods by a triangular based multi carrier pulse width modulation (PWM) scheme for the proposed CBRV inverter topology. This paper presents a comparison between different modulation strategies for CBRV inverter topology based on sinusoidal and space vector references with multi triangular carrier waves. The work strive hard to present the scrutiny that has been made between various PWM control techniques for 1–Ф seven level CBRV inverter structure. The comparison is made in terms of Total Harmonic Distortion (THD) and fundamental RMS voltage. Finally, the simulation results are included to verify the effectiveness of the proposed CBRV inverter topology and validate the proposed theory. A hardware set up was developed for a 1–Ф seven level CBRV inverter topology using FPGA based pulse generation
Side Effects of Damping Element Insertion in LCL Filter for DC/AC Inverter
No full textThe negative impacts or side effects of a damper circuit insertion in an LCL passive filter utilized to filter DC/AC inverters output voltage is presented in this paper. For comparative study, this paper discusses two damping configurations, namely series and parallel damping, as well as the LCL filter without damping element. Four criteria are used to explore the impacts of the damper circuits, i.e. their total harmonic distortions (THDs), the output voltage amplitude, the output power and the power efficiency. Theoretically and emphirically shown by previous studies, the damper can indeed reduce the peak resonance frequency of the filter in its frequency response curve. However, in any circumstance, it can potentially reduce the inverters power and efficiency, voltage output amplitude, and cannot improve its THD reduction. The analysis results have shown that the side effects depends also on the load conditions, which are different for each damping circuit configuration
Harmonic Comparison of Three Phase Direct Matrix Converter for Reactive Load with Balance and Unbalance Supply Voltage
No full textThis paper presents harmonic analysis of matrix converter using different control technique for balance and Unbalance three phase input voltage of reactive load. Since Matrix converter is subject to affected either by external disturbance or by load conditions. Due to this the supply voltage becomes unbalance. This cause improper switching of matrix converter results higher harmonics. This harmonics are harmful to the quality of the output power. The switching sequence of the matrix converter is controlled by vector control method. Different control technique is proposed in this paper to get optimized result with reduced harmonic for unbalanced and balance input voltage using PID, Fractional Order PID (PIλDδ) controller (FOPID), Particle Swarm Optimization (PSO)FOPID. PID control technique result are compared with other optimization technique for best optimum output. The FOPID controller is used to compensates the current and also improvise the quality of energy by reducing the harmonic content. The simulations and hardware results will be presented and interpreted. The effectivess of the proposed system is proven with the results is shown in this paper which produce a better steady state lesser transient rather than the conventional PID method
MPPT Control for Wind Energy Conversion System Based on a T-S Fuzzy
No full textIn this paper, we focus on the modeling and control of a wind power system based on a Permanent Magnet Synchronous Generator (PMSG). We proposed a technique of control strategies to have the maximum power from wind turbine (WT). This study deals with the problem of Maximum Power Point Tracking (MPPT) based on Takagi Sugeno fuzzy model. The stability analysis is achieved. The gains of the designed controller are calculated by solving Linear Matrix Inequality (LMI). Finally, simulation results are provided to demonstrate the validity and the effectiveness of the proposed method.
Optimization of Digital Histopathology Image Quality
No full textOne of the biomedical image problems is the appearance of the bubbles in the slide that could occur when air passes through the slide during the preparation process. These bubbles may complicate the process of analysing the histopathological images. The objective of this study is to remove the bubble noise from the histopathology images, and then predict the tissues that underlie it using the fuzzy controller in cases of remote pathological diagnosis. Fuzzy logic uses the linguistic definition to recognize the relationship between the input and the activity, rather than using difficult numerical equation. Mainly there are five parts, starting with accepting the image, passing through removing the bubbles, and ending with predict the tissues. These were implemented by defining membership functions between colours range using MATLAB. Results: 50 histopathological images were tested on four types of membership functions (MF); the results show that (nine-triangular) MF get 75.4% correctly predicted pixels versus 69.1, 72.31 and 72% for (five- triangular), (five-Gaussian) and (nine-Gaussian) respectively. Conclusions: In line with the era of digitally driven e-pathology, this process is essentially recommended to ensure quality interpretation and analyses of the processed slides; thus overcoming relevant limitations
NOC Based Router Architecture Design Through Decoupled Resource Sharing Using CABHR Algorithm
No full textA Network-on-Chips (NoCs) is rapid promising for an on-chip alternative designed in support of many-core System-on-Chips (SoCs). In spite of this, developing an increased overall performance low latency Network on chip using low area overhead has always been a new challenge. Network on Chips (NoCs) by using mesh and torus interconnection topologies have become widely used because of the easy construction. A torus structure is nearly the same as the mesh structure, however, has very slighter diameter. In this regard, we propose effective router design for Decoupled Resource sharing in a torus topology based on clustering algorithms Based Hierarchical Routing (CABHR) to get better the efficiency of NoC. We show that our approach is provides improved latency and energy consumption, overall performance developments compared to the most distinguished existing routing techniqu