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30,735 Article Results

Analysing Event-Related Sentiments on Social Media with Neural Networks

10.11591/ijai.v7.i3.pp119-124
P. Santhi Priya , T. Venkate swara Rao
Sentiment analysis is performed to determine the polarity of opinion on a subject. It has been applied to text corpora such as movie reviews, financial documents to glean information about overall-sentiment anc produce actionable data. Recent events have demonstrated that polling can be sometimes unreliable. People can be difficult to access through conventional polling methods and less than frank in polls. In the era of social media, voters are likely to more freely express their opinion on social media forums about divisive events especially in media where anonymity exists. Analyzing the prevailing opinion on these forums can indicate if there are any deficiencies in polling and can be a valuable addition to conventional polling. We analyzed text corpora from Reddit forums discussing the recent referendum in Britain to exit from the EU (known as Brexit). Brexit was an important world event and was very divisive in the run-up and post vote. We analyzed sentiment in two ways: Initially we tried to gauge positive, negative, and neutral sentiments. In the second analysis, we further split these sentiments into six different polarities based on the directionality of the positive and negative sentiments (for or against Brexit). Our technique utlilized paragraph vectors (Doc2Vec) to construct feature vectors for sentiment analysis with a Multilayer Perceptron classifier. We found that the second analysis yielded overall better results; although, our classifier didn’t perform as well in classifying positive sentiments. We demonstrate that it is possible glean valuable information from complicated and diverse corpora such as multi-paragraph comments from reddit with sentiment analysis.
Volume: 7
Issue: 3
Page: 119-124
Publish at: 2018-09-01

Maximum Power Point Tracker Using Fuzzy Logic Controller with Reduced Rules

10.11591/ijpeds.v9.i3.pp1381-1389
Adel Haddouche , Mohammed Kara , Lotfi Farah
This paper presents a fuzzy logic controller for maximum power point tracking (MPPT) in photovoltaic system with reduced number of rules instead of conventional 25 rules to make the system lighter which will improve the tracking speed and reduce the static error, engendering a global performance improvements. in this work the proposed system use the power variation and current variation as inputs to simplify the calculation, the introduced controller is connected to a conventional grid and simulated with MATLAB/SIMULINK. The simulation results shows a promising indication to adopt the introduced controller as an a good alternative  to traditional MPPT system for further practical applications
Volume: 9
Issue: 3
Page: 1381-1389
Publish at: 2018-09-01

DC-DC Boost Converter Design for Fast and Accurate MPPT Algorithms in Stand-Alone Photovoltaic System

10.11591/ijpeds.v9.i3.pp1038-1050
Norazlan Hashim , Zainal Salam , Dalina Johari , Nik Fasdi Nik Ismail
The main components of a Stand-Alone Photovoltaic (SAPV) system consists of PV array, DC-DC converter, load and the maximum power point tracking (MPPT) control algorithm. MPPT algorithm was used for extracting maximum available power from PV module under a particular environmental condition by controlling the duty ratio of DC-DC converter. Based on maximum power transfer theorem, by changing the duty cycle, the load resistance as seen by the source is varied and matched with the internal resistance of PV module at maximum power point (MPP) so as to transfer the maximum power. Under sudden changes in solar irradiance, the selection of MPPT algorithm’s sampling time (TS_MPPT) is very much depends on two main components of the converter circuit namely; inductor and capacitor. As the value of these components increases, the settling time of the transient response for PV voltage and current will also increase linearly. Consequently, TS_MPPT needs to be increased for accurate MPPT and therefore reduce the tracking speed. This work presents a design considerations of DC-DC Boost Converter used in SAPV system for fast and accurate MPPT algorithm. The conventional Hill Climbing (HC) algorithm has been applied to track the MPP when subjected to sudden changes in solar irradiance. By selecting the optimum value of the converter circuit components, a fast and accurate MPPT especially during sudden changes in irradiance has been realized.
Volume: 9
Issue: 3
Page: 1038-1050
Publish at: 2018-09-01

Control Design For Shunt Active Power Filter Based On p-q Theory In Photovoltaic Grid-Connected System

10.11591/ijpeds.v9.i3.pp1064-1071
Moh. Jauhari , Dedet Candra Riawan , Mochamad Ashari
This paper presents the control for Shunt Active Power (SAPF) filter in photovoltaic (PV) systems connected to the grid. The proposed configuration of the system consists of a photovoltaic array that connected to the grid through the three-phase inverter topology that also serves as an active filter. Photovoltaic is coupled in parallel with the direct curret (DC) side of the active filter. With this configuration, can be obtained three advantages, namely the elimination of harmonic currents caused by nonlinear load, reactive power injection, and injection of active power generated photovoltaic. The p-q Theory is used to calculate the harmonic reference current to be used to control the active filter coupled fotovoltaic in generating anti-harmonic currents. The results show that system can reduce harmonic distortion from THD 27.22% to be THD 1.05%, whereas when the active power from photovoltaic injected, the THD become 2.01%. Power sharing can also be seen from this study.
Volume: 9
Issue: 3
Page: 1064-1071
Publish at: 2018-09-01

A Novel Approach for grid integration of Cascaded H-bridge Multilevel Inverter Under Partial Shading Condition

10.11591/ijpeds.v9.i3.pp1330-1337
Swetapadma Panigrahi , Amarnath Thakur
A modular cascaded H-bridge PV inverter system is presented in this paper. The modular structure of PV inverter helps in obtaining the maximum output power of PV system along with increase the overall efficiency of the whole system. Moreover to utilize the system up to the best a distributed MPPT controller is attached with each PV panel. As partial shading causes  power imbalance at the converter output that leads to imbalance grid current, a control technique called the modulation compensation is adopted in such a way that if three phase unbalanced voltage varies directly according to unbalanced power, the injected zero sequence voltage components make the grid current balanced.
Volume: 9
Issue: 3
Page: 1330-1337
Publish at: 2018-09-01

An Optimized Speed Controller for Electrical Thrusters in an Autonomous Underwater Vehicle

10.11591/ijpeds.v9.i3.pp1166-1177
K. Vinida , Mariamma Chacko
This paper focuses on the development of a prototype of thruster motor speed controller  which exhibits robust performance for an Autonomous underwater vehicle. H infinity based speed controller with particle swarm optimized weights for a sensorless BLDC motor which is used as electrical thruster has been simulated in MATLAB/ SIMULINK and implemented using TI C2000 Delfino LaunchPad LaunchXL-F28377S and BoostXL DRV 8301. A performance comparison in reference tracking has been done with conventional PI controller and experimental results have been discussed in detail. The percentage variation in speed with respect to reference speed of proposed strategy has been observed to be 0.65% whereas it is 1.1% with PI controller. It has also been found that the proposed control strategy exhibits smooth starting with better reference tracking and less torque ripples.
Volume: 9
Issue: 3
Page: 1166-1177
Publish at: 2018-09-01

Fuzzy Model Predictive Controller for Artificial Pancreas

10.11591/ijpeds.v9.i3.pp1178-1185
Mohamed El Hachimi , Abdelhakim Ballouk , AbdNaceur Baghdad
This work consists on new tuning of Model Predictive Controllers using Fuzzy Logic method. Tree relevant parameters are automatically adjusted the prediction horizon Np, the input weight R and the output weight Q. The proposed controller is implemented in an Artificial Pancreas and tested under realistic conditions in a commercial platform of simulation. The result of the simulations revealed the success of such a method to improve the controller’s performances compared to the previous ones.
Volume: 9
Issue: 3
Page: 1178-1185
Publish at: 2018-09-01

Performance of Malaysian Insurance Companies Using Data Envelopment Analysis

10.11591/ijeecs.v11.i3.pp1147-1151
Ng Jia Bao , Rohaizan Ramlan , Fazeeda Mohamad , Azlina Md Yassin
The purpose of this study is to evaluate the performance of the local insurance in Malaysia for the period 2014-2015. The major challenge in the insurance industry is increasing competition in this market. Besides that, problematic in performance measurement to evaluate performance is another challenge in insurance industry. 24 local insurance companies involved in this study using quantitative method of Data Envelopment Analysis (DEA) output-orientation CCR model. This study utilizes three inputs and three outputs; operating expenses, equity capital and commission as well as net premium, net investment income, and net incurred claim. The secondary data sources were derived from official data of local insurance companies’ annual report respectively. The DEA-Solver-LV version 8 tools were used to analyze the data that have been collected to evaluate the performance of local insurance company. This DEA model allows integration of the performance for the insurance companies and provides management overall performance evaluation. The results showed that there are 8 efficient companies in 2014 and 9 efficient companies in 2015. The average efficiency score in 2014 was increased from 78.9% to 79.1% in 2015. The findings from this study will benefit the insurance associations in Malaysia, management of insurances companies and policy makers.
Volume: 11
Issue: 3
Page: 1147-1151
Publish at: 2018-09-01

A Novel Low Power-Application UPS consisting of an APF - Correction circuit & integrated Battery-Management system

10.11591/ijpeds.v9.i3.pp1295-1303
Venkat Gumpini , O. Chandra shekar
For the up-coming generations of power-supply systems, the load located area power-supply sources are an effective one, in terms of our requirements: simplicity, integrity, battery-backup, etc. This could follow the Normalization of power factor & Reducing THD% values on input current, which makes us to add an essential to include a power-factor correction unit at supply side in these new typical topologies. This Proposed architecture presents an integrated battery manage system which can also offers PF correction along with Galvanic-Isolation of battery in a humble single structure. [3] The proposed scheme has the reliable characters like increased efficiency, compact circuit and reduced costs associated with a traditional standalone multiple-stages UPS with PFC. This paper addresses the UPS action, the analysis and simulation results of Proposed UPS scheme.
Volume: 9
Issue: 3
Page: 1295-1303
Publish at: 2018-09-01

Dynamic Voltage Restorer for Sag and Swell Issues in Power System

10.11591/ijeecs.v11.i3.pp1243-1250
Lakshmi Lakshmi Kumari , Uma Vani Uma Vani
This paper presents the application of dynamic voltage restorers (DVR) on power distribution Systems for mitigation of voltage sags/swells at critical loads. DVR is one of the compensating types of custom power devices. The power quality is affected mainly due to the sensitive loads which results in voltage sag and voltage swells. It is necessary to investigate the suitable methods for mitigation of voltage sags. Sensitivity is the main cause of the above power quality problems and it cannot be eliminated completely as it has many other operating properties. So the next possible solution is to correct the problems caused by the sensitive equipments connected to the faulty loads. The occurrence of sag and swell varies with equipment, environment, process operations, desired control schemes etc. From the wide range of mitigation methods, the selected one has to be observed for the effect on the characteristics. These problems can be mitigated with voltage injection method using custom power device, Dynamic Voltage Restorer (DVR). In this paper we design a Dynamic Voltage Restorer (DVR) which is utilized for power quality improvement. The main power quality problems like voltage sag and swell are studied in this paper. The device used to phase out voltage sags and a swell in the distribution lines is the Dynamic Voltage Restorer (DVR). The Dynamic Voltage Restorer is a special type of power device used for providing consistent and reliable supply power to the load devices. Dynamic Voltage Restorer uses a vector control strategy for mitigating power quality problems by automatically detecting and injecting the voltage components through an injection transformer. Here comes the importance of soft computing techniques like PI controller. The system will be able to correct repeated occurrences of the power quality problems. 
Volume: 11
Issue: 3
Page: 1243-1250
Publish at: 2018-09-01

Video Quality Assessment through PSNR Estimation for Different Compression Standards

10.11591/ijeecs.v11.i3.pp918-924
Renuka Girish Deshpande , Lata L Ragha , Satyendra Kumar Sharma
Abstract           There is a threefold increase in video traffic over internet. Due to this video compression has become important. Compression of video signals is quiet an interesting task but comes at the cost of video quality. After compression, two methods are scientifically applied to evaluate the quality of video; Subjective and objective analysis. In subjective approach the compressed video is shown to a group of viewers and their feedback is recorded Objective approach aims to set up a mathematical model which can approximate the results of subjective analysis. One such approach is based on the measurement of PSNR. When a signal is applied to the encoder for compression, too much of compression results in a signal with a smaller size but at the same time quality of the signal degrades. In this paper we will compare the quality of compressed video signals produced by H.264, Mpeg2 and Mpeg4 encoder based on the values of MSE and PSNR. Lower the value of MSE, higher will be the PSNR. Comparative plots of MSE, PSNR, SSIM and images for subjective analysis have been added at the end of this paper. 
Volume: 11
Issue: 3
Page: 918-924
Publish at: 2018-09-01

9-Level Single DC Voltage Source Inverter Controlled Using Selective Harmonic Elimination

10.11591/ijpeds.v9.i3.pp1251-1262
Ibrahim Haruna Shanono , Nor Rul Hasma Abdullah , Aisha Muhammad
This paper presents an efficient cascaded H-bridge inverter topology that is controlled using an optimized selective harmonic elimination pulse width modulation technique. The switching angles are obtained by solving the nonlinear transcendental equation with the aid of genetic algorithm optimization method. Unlike the usual H-bridge converter topologies that require multiple individual direct current (DC) sources and additional switching components per voltage step, the proposed topology utilizes a single DC source to supply two full-bridge modules. The modified topology employs a cascaded multi-winding transformer that has two independent primary windings and series-connected secondary side with 1:E  and 1:3E  turn ratios. The converter topology and switching function are proven to be reliable and efficient, as the total harmonic distortion (THD) is quite low when compared with the conventional H-bridge topology controlled by other modulation techniques. This feature makes it attractive to renewable energy systems, distributed generation, and highly sensitive equipment such as those used in medical, aerospace, and military applications. The topology is simulated using a PSIM package. Simulation results show that all the 11-level lower order odd harmonics are eliminated or suppressed in compliance with the SHE elimination theorem of (N-1).
Volume: 9
Issue: 3
Page: 1251-1262
Publish at: 2018-09-01

Solid-State Transformer (S2T) of Single Phase Matrix Converter

10.11591/ijpeds.v9.i3.pp997-1005
Zafirah Zainuddin , Rahimi Baharom , Ihsan Mohd Yassin , Khairul Safuan Muhammad
Solid-State Transformer (S2T) also known as Power Electronic Transformer (PET) is applied in various industrial fields compared to the conventional transformer due to it flexible voltage transfer ratio, high power density, and low harmonic distortion. This paper presents the S2T of Single Phase Matrix Converter (SPMC) that acts as cyclo-converter. A 1kHz frequency was synthesized on the primary side of the transformer using Pulse Width Modulation (PWM) technique, whilst, the output converted by the SPMC that produces the 50Hz frequency. A part of AC to AC operation, the switching algorithm for safe-commutation technique is also presented to solve the commutation problem caused by the usage of inductive load. Minimization of size, losses and optimal efficiency are the advantages of this approach. The proposed model was simulated by using MATLAB/Simulink (MLS).
Volume: 9
Issue: 3
Page: 997-1005
Publish at: 2018-09-01

Cat Swarm Optimization to Shunt Capacitor Allocation in Algerian Radial Distribution Power System

10.11591/ijai.v7.i3.pp143-152
Amar Hamzi , Rachide Meziane
This paper presents a Cat Swarm Optimization (CSO) Algorithm optimization method to shunt capacitor placement on distribution systems under capacitor switching constraints. The optimum capacitor allocation solution is found for the system of feeders fed through their transformer and not for any individual feeder. The main advantages due to capacitor installation, such as capacity release and reduction of overall power and energy losses are considered. The capacitor allocation constraints due to capacitor-switching transients are taken into account. These constraints are extremely important if pole-mounted capacitors are used together with station capacitor bank. Cat Swarm search algorithm is used as an optimization tool. An illustrative example for Algerian example is presented.
Volume: 7
Issue: 3
Page: 143-152
Publish at: 2018-09-01

Error-correcting Coding Usage for Data Transmission Through Power Lines

10.11591/ijpeds.v9.i3.pp1423-1431
Aleksey Ishchenko , Vladimir Shevelev , Alexander Naronov , Alexander Tcherepanov , Boris Shulgin
A concept of data transmission within downhole telemetry systems in oilfield industry through power lines is presented. Based on this concept, MATLAB/Simulink models simulating communication lines in downhole telemetry systems are built, which can be used as prototypes for development of real systems. The most appropriate signal modulation methods for data transmission in downhole telemetry systems are suggested and discussed. The influence of high-voltage interference on signal transmission through power line from downhole unit to ground based unit is simulated. Usage of error-correcting coding methods for data transmission such as Hamming code, Reed-Solomon code, BCH code is suggested, and its efficiency is demonstrated.
Volume: 9
Issue: 3
Page: 1423-1431
Publish at: 2018-09-01
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