Improvement of Text Dependent Speaker Identification System Using Neuro-Genetic Hybrid Algorithm in Office Environmental Conditions

In this paper, an improved strategy for automated text dependent speaker identification system has been proposed in noisy environment. The identification process incorporates the Neuro-Genetic hybrid algorithm with cepstral based features. To remove the background noise from the source utterance, wiener filter has been used. Different speech pre-processing techniques such as start-end point detection algorithm, pre-emphasis filtering, frame blocking and windowing have been used to process the speech utterances. RCC, MFCC, ?MFCC, ??MFCC, LPC and LPCC have been used to extract the features. After feature extraction of the speech, Neuro-Genetic hybrid algorithm has been used in the learning and identification purposes. Features are extracted by using different techniques to optimize the performance of the identification. According to the VALID speech database, the highest speaker identification rate of 100.000% for studio environment and 82.33% for office environmental conditions have been achieved in the close set text dependent speaker identification system

Automatic Road Extractions from High Resolution Satellite Imagery Using Road Intersection Model in Urban Areas

This paper proposes intersection model and strategy for road extraction from high resolution satellite images. Satellite images are rich in information. For Geographic Information System (GIS), many features require fast and reliable extraction of roads and intersections. They are also complex to analyze. Satellite image provides useful data that is extracted from satellite image of the urban area. Automatic extraction of the road intersections from the urban areas has been a challenging topic because the high resolution satellite images contain multiple layers that represent roads, buildings, and other high density objects. Our goals is to automatically separate the road layer from the other layers then extract the road intersections. Usually traditional image processing methods don't achieve satisfied performance in case of satellite images. This paper proposes a modified and a cost effective method for road extraction from high resolution satellites images. In order to find the precise road intersection of urban areas we have divided whole process into two sequential modules: first, extraction of road line using different Morphological direction filtering to automatically eliminate the other layers from road layer and finally, extraction of road intersections to determine the road orientation and interconnectivity. We applied this method to a set of randomly selected high resolution satellite image from urban and semi urban areas and the correctness of road network extraction reaches 95.71%, significantly higher than those of other existing road extraction methods

Genetic Algorithm Based Reactive Power Management by SVC

This paper contains an approach of a generalized optimization formulation regarded as genetic algorithm with a view to determining the optimal location of distributed generators in 10-bus network offering reactive power capability. It is certainly the case that the reactive power management plays a noteworthy role, when it is required to improve not just the voltage profile but the voltage stability as well. In this paper, the requisite reactive power planning has been precisely solved by the evolutionary genetic algorithm, which is based on biological metaphor, in which best individuals are selected among parents and offspring generation. In addition, genetic algorithm does not need initial information about the system to begin the searching process since it works only with the chromosomes which will be optimized according to the objective functions and the proper constraints. As far as this paper goes, the injection of 228.5469553MVAR reactive power by Static Var Compensator (SVC) is enough to maintain voltage stability throughout the system.DOI:http://dx.doi.org/10.11591/ijece.v4i2.587

INTEGRATION OF THE OUTPUT OF A SILICON SOLAR CELL TO THE GRID SYSTEM

With the advent of the 21st century, the utilization of renewable energy in modern power generation has been leapt to a level that was unimaginable only even 100 years ago. Solar energy is one of the popular renewable energy sources as it is abundant in nature especially warm predominant countries like Bangladesh. In addition, some noteworthy upsides of solar energy are free fuel such as sunlight is free, environmental friendly operation, minimal maintenance and longer service life. This paper furnishes knowledge about the performance of a single crystalline silicon solar cell, based on the practical experimental results that have been obtained from different connections of the used modules like single module, series connection of double modules and parallel connection of double modules. The comparative results show that maximum open circuit voltage, maximum output power and maximum fill factor have been obtained from series connection of double modules whereas, parallel connection of double modules has given the largest amount of short circuit current. On the other hand, highest efficiency has been derived in case of single module connection. Besides, suitable arrangements have also been demonstrated in this paper so that the output of these solar modules can be connected to the grid system with a view to meeting up the increased power demand

A Novel Hexagonal-Shaped Multilevel Inverter with Reduced Switches for Grid-Integrated Photovoltaic System

To date, the grid-connected solar photovoltaic (PV) system has drawn consideration from researchers and academicians due to the speedy improvement and the declining price of solar panels. The proficiency and dependability of a grid integrated PV system rest mainly on the power conversion unit and the proper controlling mechanism. This paper introduces a novel asymmetric hexagonal-shaped fifteen-level inverter designed to feed a grid-integrated solar PV system. First, it aims to reduce the number of components and thereby decrease the installation space and cost of the multilevel inverter. Moreover, it has a low total blocking voltage (TBV) and total device rating (TDR) and uses few switching devices for generating per level of output voltage. The proposed topology utilizes only eight switching devices for generating fifteen levels at the output, which is lower than conventional multilevel inverter topologies. Here, a low-frequency modulation scheme using the half-height (HH) method generates switching pulses to minimize the complexity. The proposed multilevel inverter topology is also validated through the simulations in the MATLAB SIMULINK environment. The proposed inverter need for filters is illustrated according to different grid codes for integrating PV systems to the grid

A Comparative Analysis of Soft Switching Techniques in Reducing the Energy Loss and Improving the Soft Switching Range in Power Converters

This paper presents a comparative analysis of the zero-voltage zero-current switching (ZVZCS) soft switching technique with zero-voltage switching (ZVS) and zero-current switching (ZCS) counterparts. The generalization of the voltage–current crossover or the energy loss factor obtained from simulation of the prototype converter shows that the ZVZCS significantly reduces the losses and helps to improve the efficiency of the converter as compared to the ZVS or the ZCS. On the other hand, it is also found that the soft switching range of operation of the ZVS and the ZCS is largely affected by the maximum switch voltage and switch current, respectively. In contrast, these factors have a negligible effect on the ZVZCS operation which results in an extended range of soft switching operation. Additionally, a detailed PSPICE simulation is performed for selected ZVS, ZCS, and ZVZCS topologies from the recent literature, and the switching losses in the main switches of the converters are measured. It is observed that the energy losses in the ZVZCS mode are reduced on average by approximately 26% at turn on and 20% at turn off as compared to the ZVS and the ZCS. Furthermore, the low standard deviation in this mode confirms a stable low-loss profile which renders an extended soft switching range. An experimental test is also conducted by building the prototype converter to verify the simulation results. It is found that the switching losses are minimum while the converter is operated in the ZVZCS mode. Additionally, the efficiency drop remains consistently low as compared to the ZVS and the ZCS in the whole operating range. Accordingly, the simulation and the experimental results are both found to be consistent