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International Journal of Research in Science & Technology

Journal Papers (31) Details Call for Paper Manuscript submission Publication Ethics Contact Authors' Guide Line
1 Integration of Unified Power Quality Controller with DG, Sk. Chinni Bhavani, T. Prasanth, V. Srilekha, P. Phaneendra and Mrs. M. Anitha
This paper gives an insight into the analytical results of the intergration of Unified power quality controller (conditioner) with distribution generation system. The intergration is achieved by connecting the DClink throught rectifier to the distribution generatoion along with thwe connection of the series and shunt inverter to the same dc link. This type of connection can account for the voltage sag, voltage swell, along with the reduction of harmonics and also compensation of reactive power. The analysis is supported with the simulation which will are discussed in detail in the paper.
2 An Efficient User Privacy and Protecting Location Content in Location Based Service, D.Linta Nayagi and Mr.V.Gunalan
In location-based query a user wants to query a database of location data, known as Points Of Interest (POIs), and does not want to reveal his/her location to the server due to privacy concerns; (ii) the owner of the location data, that is, the location server, do Abstract: Nowadays, it is very easy for a person to learn his/her location with the help of a Global Positioning System (GPS) enabled device. A location s not want to simply distribute its data to all users. The location server desires to have some control over its data, since the data is its asset. A major enhancement upon previous solutions by introducing a two stage approach, the first step is based on Oblivious Transfer using homomorphic encryption and the second step is based on Private Information Retrieval, to achieve a secure solution for both parties. Introduce a security model and analyse the security in the context of our protocol. To highlight a security weakness of our previous work and present a solution using efficient homomorphic system.
3 An Efficient User Privacy and Protecting Location Content in Location Based Service, D.Linta Nayagi and Mr.V.Gunalan
In location-based query a user wants to query a database of location data, known as Points Of Interest (POIs), and does not want to reveal his/her location to the server due to privacy concerns; (ii) the owner of the location data, that is, the location server, do Abstract: Nowadays, it is very easy for a person to learn his/her location with the help of a Global Positioning System (GPS) enabled device. A location s not want to simply distribute its data to all users. The location server desires to have some control over its data, since the data is its asset. A major enhancement upon previous solutions by introducing a two stage approach, the first step is based on Oblivious Transfer using homomorphic encryption and the second step is based on Private Information Retrieval, to achieve a secure solution for both parties. Introduce a security model and analyse the security in the context of our protocol. To highlight a security weakness of our previous work and present a solution using efficient homomorphic system.
4 Implementation of Windowing Technique for Minimizing the Side Lobes in Antenna Array Design, Sk. Khadar Basha and Sk. Abdul Rehman
The objective of this project is to generate the radiation pattern of linear arrays like broad side array and end fire array by reducing the side lobes. This project is implemented by using MATLAB. For some applications, single element antennas are unable to meet the gain or radiation pattern requirements so combining several single antenna elements in an array can be a possible solution. Array is a system of similar antennas oriented similarly to get greater directivity in a desire direction. Various techniques can be used to reduce the side lobes in the radiation pattern. Here, we employ windowing techniques for the reduction of side lobes. The 4-term Blackman-Harris window function is a good general purpose window, having side lobe rejection in the high 90s dB and having a moderately wide main lobe. The Kaiser-Bessel window function has a variable parameter, beta, which trades off side lobes for main lobe. It compares roughly to the Blackman-Harris window functions, but for the same main lobe width, the near side lobes tend to be higher, but the further-outside side lobes are low. Antennas exhibit a specific radiation pattern. Tapering of side lobes in the radiation pattern has several advantages and applications. These have wide importance in specific military applications. Military antennas are designed to have a narrow main beam as reasonable to give higher resolution and the lowest side lobes possible to reject echoes and jamming at other elevation angles. Radar was first developed for military purposes. The early surveillance radars often used a line feed and a cylindrical reflector. The radiation pattern from the line feed was shaped to provide lower side lobes and a slightly broader main beam with slightly less gain.
5 Experimental Investigation on Hybrid Steel Fiber Reinforced Concrete Beam Column Joints Under Cyclic Loading, J.Devi Keerthana and Ch.Surendra Reddy
An investigation on the performance of reinforced concrete beam column joints under cyclic loading is reported. Joints have been cast with adequate and deficient shear capacity and bond of reinforcements at the beam column joint. Steel Fiber Reinforced like crimped hook end have been applied on the joints in different volume fraction and aspect ratios. The column subjected to an axial force while the beams are subjected to cyclic load with controlled displacement. The displacement is increased monotonically using a hydraulic push and pull jack. The hysteretic curves of the specimen have been plotted. The energy dissipation capacity of retrofitted beam column joints with various hybrid steel fibres configurations has been compared. The results show that the strengthened beam column joint exhibit increased strength, stiffness, energy dissipation and composite action until failure.
6 Experimental Studies on Retrofitting of RCC Beams Using GFRP, Md.Vazeer Ahmed and Ch.Surendra Reddy
The studies conducted on the retrofitting of RCC beams using GFRP are limited. So it is essential to study the shear carrying capacity, flexural carrying capacity and ductility of flexural deficient beams by retrofitting with GFRP. u wrapping technique was adopted for both shear deficient beams and flexural deficient beams. The number of layers of GFRP was considered as variable. The effect of increasing the number of layers of GFRP has been studied. In this work retrofitting of RCC beam of shear deficient beam and flexural deficient beam and flexural deficient beam using GFRP lamination will be studies. Fourteen beams of size 100mm*150mm*1200mm were cast. Out of this two control beam one was used as shear deficient beam and another was used as flexural deficient beam . remaining twelve beams six beams were shear deficient used for retrofitting and six beams were flexural deficient used for retrofitting. Shear deficient control beam (SDCB) and flexural deficient control beams (FDCB) were loaded upto ultimate load in the compression testing machine of 300 tones capacity. Shear deficient and and flexural deficient beams were retrofitting using GFRP which was bonded with epoxy resin.. load deflection behavior of beam, retrofitting with different layers of stitched mat and woven roving was compared. Study of ductility of flexural deficient beams was made.
7 Performance Evaluation and Cost Analysis of Selected Shielded Manual Metal Arc Welding (SMMAW) Steel Electrodes, B.O. Afolabi, T.A. Adegbulugbe and A.O.D. Adejumo
The work investigated the effect of electrodes on consumption rate and mechanical behavior of welded mild-steel and galvanized-steel joints, to ascertain their performance level under service conditions, which has increased joint failure and increased equipment cost of maintenance. 20 welded mild-steel and galvanized-steel flat bars ( x ) produced from shielded manual metal arc welding (SMMAW) were prepared using mild steel electrodes, gauge 12 of four selected different brands from local hardware market. Standard methods were applied for tensile properties using Ultimate tensile test machine. Also, the consumption rate of each brand of electrode in joining specified metal types were ascertained through 5 replications within specified time frame (6 seconds) for each metal type. Results obtained from tensile tests in respect to allowable maximum load, breaking point and yield point. The result showed allowable maximum load at tensile strength of 5524.767 N and 5131.088N attained for mild steel welded with Zika electrode and galvanized steel welded with Oerlikon electrode respectively. Changes were noticed in the modulus of elasticity at yield point for galvanized steel welded with Fed electrode, and mild steel welded with China electrode. The consumption rate with equivalent price value was projected to 8 working hours, this gave maximum consumption rate of 528.4 sticks of electrodes (2.11 packs), corresponded to price value of 4,227naira in respect to galvanized steel welded with Zika. It was therefore recommended that Zika electrode brand are in no-way fit to be used on galvanized steel based on tensile properties test and consumption rate. Zika electrode brand is most suitable for mild steel joints for tensile properties, while Oerlikon electrode brand is best suited for galvanized steel joints when the same property is desired. All specified electrode brands are found to be more cost effective when used on mild steel compared to galvanized steel.
8 Integration of Litho-Units Derived From Satellite Data, Dr. A. Subhash Babu , Dr.G. Udaya Laxmi and Dr. G. Ramadass
Remote sensing techniques were applied to demarcate lithological and structural features of the area around Mahabubnagar district of Telangana and parts of Gulburga district of Karnataka of eastern Dharwr craton Through Spectral Geological techniques like False Color Composition (FCC)/ Band Combination, Band Indices/ Band Ratios, Principle Component Analysis (PCA), Minimum Noise Factor (MNF), Spectral Curve Matching mainly to identify MgOH rich soils, which are weathered from kimberlites, Spectral Angle Mapper (SAM), End-Member identification etc. are used to discriminate the lithology of the study area using LANDSAT 8 and ASTER VNIR, SWIR and TIR wavelengths. Surface structures, which could be probable subsurface indicators of faults, intersections of these are main source of kimberlite emplacement are also identified with various techniques, these are penetrated into deep-seated.
9 A Study of SEPIC Converter Based Fuzzy Logic Controller For Hybrid System, Balaganesh.S and Perumal.R and T.S.Anusha
This paper presents the study of integrated hybrid renewable energy system. The wind and solar are used as input sources for the hybrid system. The proposed system involves the design of photovoltaic (PV) and wind energy conversion system (WECS).The system is designed for constant wind speed and varying solar irradiation and insolation. Maximum power point tracking (MPPT) algorithm is used to extract the maximum power from PV array. The integration of two input sources is done by single-ended primary-inductor converter. Fuzzy logic controller is used to control the duty cycle of one of the converter switch thereby extracting the maximum power from solar array. The system consists of photovoltaic (PV) array, wind energy conversion system (WECS), single-ended primary-inductor converter, voltage source inverter (VSI), LC filter and three phase load.
10 Review of Reduction of Leakage Current In Cascaded Multilevel Inverter, M.S.Vinu Kumar, A.Subanth Williams, P.Eugine Paul and A.Perumal
Multilevel inverters are a source of high power, often used in industrial applications and can use either sine or modified sine waves. A multilevel inverter uses a series of semiconductor power converters (usually two to three) thus generating higher voltage. Reverse leakage current in a semiconductor device is the current from that semiconductor device when the device is reverse biased. In earlier method transformer is used for generating multilevel output and grid synchronization. Transformer increases the leakage current. Now transformerless method and sine modulation techniques are presented to reduce the leakage current.
11 Review of Low Voltage Ride Through Methods in PMSG, A.Bala Alagu Raja, S.Ajin, R.Suja, A. Subanth Williams
In this paper discussed about low voltage ride through (LVRT) scheme for permanent magnet synchronous generator (PMSG) and wind energy conversion system. Wind generation system has potential application for the grid support. The voltage of the direct driven permanent magnet wind generators (PMSG) is variable due to the intermittent nature of the wind energy. With increasing penetration of wind turbine (WTs) in the grid. Grid connection codes in most countries require that WTs should remain connected to the grid to maintain the reliability during and after a short-term fault. The controllers for grid-side converters are coordinated to provide fault ride-through capability. The generator side is forced by space vector modulation and grid implemented field oriented control (FOC).
12 Review of Step Down Converter With Efficient ZVS Operation, M. Jesu Selva Berozemine, A. Chitra, M. Mahalaksmi
This paper presents the review of step down converter with efficient ZVS operation. The designed buck converter uses ZCS technique and the function is realized so that the power form is converted from 12V DC 5V DC (1A). A detailed analysis of zero current switching buck converters is performed and a mathematical analysis of the mode of operation is also presented. In order to reduce the switching losses in associated with conventional converters; resonant inductor and resonant capacitor (LC resonant circuit) is applied which helps to turn on-off the switch at zero current. The dc-dc buck converter receives the energy from the input source, when the switch is turned-on. The buckbuck converters have characteristics that warrant a more detailed study. The buck converters under discontinuous conduction mode /continuous conduction mode boundary.
13 Detection of DNA Damage Using Comet Assay Image Analysis, Vijay Patil, Mayur Ingale, Pravin Dhulekar and Yogesh Gaikwad
Reactive species such as free radicals are constantly produced in vivo and DNA is the very important target of oxidative stress. Oxidative DNA damage is considered as a predictive biomarker to monitor the risk of development of many diseases. The comet assay is widely used for specifying oxidative DNA damage at a single cell level. The analysis of comet assay output images, however, poses considerable challenges. The comet assay, also known as single-cell gel electrophoresis (SCGE), is a simple, sensitive and reliable method for studying DNA damage caused by physical and chemical agents. So the comet assay is a well-established, simple, versatile, visual, rapid, and sensitive method used extensively to assess DNA damage quantitatively and qualitatively at single cell level. The comet assay is most frequently used to analyze white blood cells or lymphocytes in human bio monitoring studies. So through the analysis of comet assay image we can detect edge of damaged DNA comet isolating it from undamaged DNA.
14 Power Quality Improvement by UPQC based on Voltage Source Converters, Kambham Ravi Shankar, Ch. Narendra Kumar and Ch. Rambabu
In modern power system consists of wide range of electrical, electronic and power electronic equipment in commercial and industrial applications. Since most of the electronic equipments are nonlinear in nature these will induce harmonics in the system, which affect the sensitive loads to be fed from the system. These problems are partially solved with the help of LC passive filters. However, this kind of filter cannot solve random variation in the load current wave form and voltage wave form. Active filters can resolve this problem. However, the cost of active filters is high. They are difficult to implement in large scale. Additionally, they also present lower efficiency than shunt passive filters. One of the many solutions is the use of a combined system of shunt and active series filters like Unified Power Quality Conditioner (UPQC) which aims at achieving a low cost under highly effective control. The UPQC device combines a shunt active filter together with a series active filter in a back-to-back configuration, to simultaneously compensate the supply voltage and the load current or to mitigate any type of voltage and current fluctuations and power factor correction in a power distribution network, such that improved power quality can be made available at the point of common coupling. The control strategies are modeled using MATLAB/SIMULINK. The performance is also observed under influence of utility side disturbances such as harmonics and voltage sags. The simulation results are compared without and with UPQC for the verification of results.
15 Line Integration of Bidirectional Inverter with Buck Boost for Microgrid , M.Shyamala, M.Palaniselvi and A.Chitra
Line-interactive uninterruptible power supply (UPS) systems are good candidates for providing energy storage within a micro-grid. Power can be imported from the grid by the UPS to charge its battery in grid-connected mode. The UPS supplies local distributed loads in parallel with other sources in stand-alone mode. In this paper, Power flow is controlled using the frequency and voltage drooping technique. It improves the reliability, economy and efficiency.
16 Adaptive Modulation with Moments based Signal-to-Noise Ratio Estimator, Garigipati Vijay Kumar
Data-Aided Signal-to-Noise-Ratio (SNR) estimation is considered for time selective fading channels whose time variation is described by a polynomial time model. The inherent estimation accuracy limitations associated with the problem are quantified via a CramerRao Bound analysis. A maximum likelihood type class of estimators is proposed and its exact, non-asymptotic performance is computed. The standard, constant channel SNR estimator performance is determined in the presence of channel polynomial order mismatch. Simulations results are presented which verify the effectiveness of the technique as well as its performance advantage over previously proposed methods.
17 L-Z Source based Diode Clamped MLI for multilevel generation, Pulugujju Srinivasa Rao, T. Srinivasa Rao
Multilevel inverters (MLI) have the capability of producing less distorted ac voltages across its output terminals. The output available across any MLI is a stepped sine wave. Among the available configurations diode clamped topology has the ability of providing reverse recovery ability for the switches. So in this project a new converter topology based on Z-Source configuration combined with a diode clamped multilevel is proposed. Usually classical Z-Source inverters contain a diode, capacitors and inductors for boosting the voltage. The Z-Source inverters suffer with inrush currents and resonance. The disadvantages of these capacitors are eliminated with the help of a new circuit comprising of inductors and diodes. The Z-Source of the network contains only inductors. The Z-Source acts like a current source and is cascaded with a diode clamped multilevel inverter. The main advantage of this configuration is that size of the filter is minimized and has the ability of producing least distortion in output current when the system is operated with lagging power factor loads. The proposed circuit is modelled and simulated using MATLAB. Total harmonic distortion levels are estimated with and without filters when supplying resistive and combination of resistive and inductive loads.
18 NEUTRON STARS - UNIQUE COMPACT OBJECTS OF THEIR OWN, R. Sashikanth
This paper outlines the study of neutron stars right from the early theoretical predictions and observations by various astrophysicists which gradually aroused huge interests among the scientific community, to the latest developments in the scientific analysis of the behavior of the different categories of compact objects. Although white dwarfs, neutron stars, brown dwarfs, Black Holes etc.fall under the category of compact objects, each of them is unique in its own way.
19 A Study on the Local Property of indexed Summability of a factored Fourier Series, B.P.Padhy, S.K.Nayak, Mahendra Misra and U.K.Misra
In this paper we have established a theorem on the local property of k n n N, p ,? ;? summability of a factored Fourier series.
20 Improving the Signal Quality of Multistream Data Transmission in 4G Services, Ms. Emil Jenitta.R and Mrs. Sherin Shibi
Relaying is one of the key feature in wireless standards that expand the coverage of wireless networks. The ever increasing demand for very high data rate servicesmake use of multicarrier modulation techniques. This project explains about the improvement in bit error rate and elimination of interference. Conjugate Cancellation scheme for transmitter design, Phase Rotated Conjugate Cancellation scheme for receiver design and Equalize and Forward relay provides an efficient method for interference cancellation. In transmitter side only one phase rotation is applied and two phase rotations are applied at the receiver side. With such rotations the mismatch between the transmitter and the receiver can be tracked. The optimal solutions can be obtained by Block least mean square algorithm. Simulation results using the metrics viz. SNR, BER shows the performance of the proposed scheme achieves the interference free transmission and improvement in bit error rate.
21 Analysis of Voltage and Current Variations in Hybrid Power System, M .N .V .Subbarayudu, M. L .Pravalika, P.V.Avinash, P.Bhavya Sree N.Chaitanya and V.Sarayu
In this paper, a detailed dynamic model and simulation of a solar cell/wind turbine/fuel cell hybrid power system is Developed using a novel topology to complement each other and to alleviate the effects of environmental variations. Comparing with the nuclear energy and thermal power, the renewable energy is inexhaustible and has non-pollution Characteristics. Here Ultra-capacitors are used in power applications requiring short duration peak power. The voltage variation at the output is found to be within the acceptable range. The output fluctuations of the wind turbine varying with wind speed and the solar cell varying with both environmental temperature and sun radiation are reduced using a fuel cell. Therefore, this system can tolerate the rapid changes in load and environmental conditions, and suppress the effects of these fluctuations on the equipment side voltage. The proposed system can be used for off-grid power generation in non interconnected areas or remote isolated communities. Modeling and simulations are conducted using MATLAB/Simulink software packages to verify the effectiveness of the proposed system. The results show that the proposed hybrid power system can tolerate the rapid changes in natural conditions and suppress the effects of these fluctuations on the voltage within the acceptable range.
22 DTC Scheme for a Four-Switch Inverter-Fed PMBLDC Motor Emulating the Six-Switch Inverter Operation, A. Rani, A. Amarendra
The paper deals with the direct torque control (DTC) of brushless DC (BLDC) motor drives fed by four-switch three phase inverters (FSTPI) rather than six-switch inverters (SSTPI) in conventional drives. For any three phase inverter require six switches, but these switches are reduced to four. This reduction of power switches from six to four improves the reliability of the inverter, size of the inverter is reduced and cost of the inverter is also reduces. The FSTPI could be regarded as a reconfigured topology of the SSTPI in case of a switch/leg failure which represents a crucial reliability benefit for many applications especially in electric and hybrid propulsion systems. The DTC of FSTPI-fed BLDC motor drives is treated considering two strategies, such as: 1) DTC-1: a strategy inspired from the one intended to SSTPI-fed BLDC motor drives; 2) DTC-2: a strategy that considers a dedicated vector selection subtable in order to independently control the torques developed by the phases connected to the FSTPI legs during their simultaneous conduction. The operational principle of the four-switch BLDC motor drive and the developed control scheme are theoretically analyzed and the performance is demonstrated by simulation.
23 Reduction of Frequency offset Using Joint Clock for OFDM Based Cellular Systems Over Generalized Fading Channels , S..L.S.Durga, M.V.V.N.Revathi, M.J.P.Nayana, Md.Aaquila Fathima and K.Murali
This project addresses the problem of clock synchronization between a base station (BS) and a mobile station (MS). A conventional technique for clock synchronization is that the MS clock is derived from the downlink signal originated from a base station. In cellular systems, a base station and mobile stations need to be synchronized before data exchange. Since the base station clock reference is more accurate, a mobile station typically derives its clock reference from the base station. But the carrier frequency offset due to Doppler shift may have harmful effects on the local clock derivation. This project proposes a joint clock and frequency synchronization technique between a base station and a mobile station, which is effective even with Doppler shift. We derive the joint estimation algorithm by analyzing the phase and the amplitude distortion caused by the sampling frequency offset and the carrier frequency offset. Simulation results showing the effectiveness of the proposed algorithm will also be presented.
24 Reduction of Frequency offset Using Joint Clock for OFDM Based Cellular Systems Over Generalized Fading Channels , S..L.S.Durga, M.V.V.N.Revathi, M.J.P.Nayana, Md.Aaquila Fathima and K.Murali
This project addresses the problem of clock synchronization between a base station (BS) and a mobile station (MS). A conventional technique for clock synchronization is that the MS clock is derived from the downlink signal originated from a base station. In cellular systems, a base station and mobile stations need to be synchronized before data exchange. Since the base station clock reference is more accurate, a mobile station typically derives its clock reference from the base station. But the carrier frequency offset due to Doppler shift may have harmful effects on the local clock derivation. This project proposes a joint clock and frequency synchronization technique between a base station and a mobile station, which is effective even with Doppler shift. We derive the joint estimation algorithm by analyzing the phase and the amplitude distortion caused by the sampling frequency offset and the carrier frequency offset. Simulation results showing the effectiveness of the proposed algorithm will also be presented.
25 Internet of Things -Overview, A.Vineela and L. Sudha Rani
The Internet of Things (IoT), also referred to as the Internet of Objects, will change everythingincluding ourselves. This may seem like a bold statement, but consider the impact the Internet already had on education, science, communication, business, government, and humanity. Clearly, the Internet is one of the most important and a powerful creation in all of human history. This paper discussesIOT architecture, IOT applications and limitations of IOT.
26 Performance Evaluation of Computationally Efficient Energy Detection Based Spectrum Sensing for Cognitive Radio Networks, G.Navya, Y.Mounika, M.Sirisha, V.Mounika and K.Murali
The rapid growth of bandwidth demanding wireless technologies has led to the problem of spectrum scarcity. However, studies show that licensed spectrum is underutilized. Cognitive radio technology promises a solution to the problem by allowing unlicensed users, access to the licensed bands opportunistically. A prime component of the cognitive radio technology is spectrum sensing. Many spectrum sensing techniques have been developed to sense the presence or not of a licensed user. This paper evaluates the performance of the energy detection based spectrum sensing technique in noisy, fading, jamming, interference environments. Both single user detection and cooperative detection situations were investigated. Closed form solutions for the probabilities of detection and false alarm were derived. The analytical results were varied by numerical computations using Monte Carlo method with MATLAB. The performance of the computationally efficient energy detection (CE-ED) techniques were evaluated by use of Receiver Operating Characteristics (ROC) curves over additive white Gaussian noise (AWGN) and fading (Rayleigh & Nakagami-m) channels. Results show that for single user detection, the energy detection technique performs better in AWGN channel than in the fading channel models. The performance of cooperative detection is better than single user detection in fading environments.
27 Support Vector Machine for Wind Speed Prediction , Mrs. Sangita B. Patil and Mr. Bapu K. Patil
The energy is a vital input for the social and economic development of any nation. With increasing agricultural and industrial activities in the country, the demand for energy is also increasing. The increasing use of natural and renewable energy sources is needed to take the burden of our current dependency on fossil fuels. Development and analysis of renewable energy models helps utility in energy forecasting, planning, research and policy making. The wind power is a clean, inexhaustible, and almost a free source of energy. But the integration of wind parks with the power grid has resulted in many challenges for the utility in terms of commitment and control of power plants. As wind speed and wind direction fluctuate frequently, the accurate long-term and short-term forecasting of wind speed is important for ascertaining the wind power generation availability. To deal with wind speed forecasting, many methods have been developed such as physical method, which use lots of physical considerations to reach the best forecasting precision and other is the statistical method, which specializes in finding the relationship of the measured power data. Wind speed can be predicted by using time series analysis, artificial neural network, Kalman Filter method, linear prediction method, spatial correlation models and wavelet, also by using the support vector machines. In this paper, the SVM is used for day ahead prediction of wind speed using historical data of wind park. In this paper Support Vector Machine (SVM) results are compared with feedforward Backpropagation neural network. It is observed that the Mean Absolute Percentage Error (MAPE) by SVM method is around 7% and correlation coefficient is close to 1. This justifies the ability of SVM for wind speed prediction task than Backpropagation algorithm.
28 A Novel Approach for Interference Suppression Using a Improved LMS Based Adaptive Beam forming Algorithm, Julakanti Goutham Reddy , Thota Krishna Teja and Battina Siva Seshu
A novel adaptive beam forming technique is proposed for wireless communication applications based on the minimum bit error rate (MBER) criterion known as LMS algorithm. LMS (Least Mean Square) algorithm is used for steering the antenna beam electronically. Using the Rectangular, Hamming, Kaiser, Chebyshev windows both the block-data and sample-by-sample adaptive implementations of the MBER solution are developed. By making use of window techniques half power beam width of an antenna is enhanced using Matlab simulation. The gain of the system will definitely improve the performance of CDMA based system, where the number of interferes is quite large and helps to increase the spectral efficiency of wireless communication systems. Any beam former that can depress the large number of interferers will improve the capacity and performance. Such beam formers are called smart antennas. They improve signal to interference ratio (SIR) of the communication system efficiently by forming narrow beam towards desired user and low side towards undesired users. Smart antennas offer a broad range of ways to improve wireless system performance.
29 A Novel Approach for Interference Suppression Using a Improved LMS Based Adaptive Beam forming Algorithm, Julakanti Goutham Reddy , Thota Krishna Teja and Battina Siva Seshu
A novel adaptive beam forming technique is proposed for wireless communication applications based on the minimum bit error rate (MBER) criterion known as LMS algorithm. LMS (Least Mean Square) algorithm is used for steering the antenna beam electronically. Using the Rectangular, Hamming, Kaiser, Chebyshev windows both the block-data and sample-by-sample adaptive implementations of the MBER solution are developed. By making use of window techniques half power beam width of an antenna is enhanced using Matlab simulation. The gain of the system will definitely improve the performance of CDMA based system, where the number of interferes is quite large and helps to increase the spectral efficiency of wireless communication systems. Any beam former that can depress the large number of interferers will improve the capacity and performance. Such beam formers are called smart antennas. They improve signal to interference ratio (SIR) of the communication system efficiently by forming narrow beam towards desired user and low side towards undesired users. Smart antennas offer a broad range of ways to improve wireless system performance.
30 A Particle Swarm Optimization for Optimal Reactive Power Dispatch, Suresh Kumar and Sunil Kumar Goyal
This paper presents particle swarm optimization (PSO) based approach for solving optimal reactive power dispatch for minimizing power losses. The control variables are bus voltage magnitudes (continuous type), transformer tap settings (discrete type) and reactive power generation of capacitor banks (discrete type). The algorithm solution of PSO is tested on a standard IEEE 30 Bus system. The intention is to minimize power losses by optimizing the reactive power dispatch with optimal setting of control variables without violating inequality constraints and satisfying equality constraint. The detailed results for different cases have been listed
31 Study of THD in Different CHB MLIs Controlled With Unipolar and Bipolar Carrier Based Modulation Techniques, Jeeri Naga Ramakrishna and T. Srinivasa Rao
Multi-level inverters (MLIs) are gaining popularity due to their inherent advantages like better harmonic distortion, ability of producing higher magnitudes of AC voltages. As these converters uses many cascaded connection of many small units the switches used in devices are subjected to less voltage stresses. H-bridge based multilevel inverter can increase the number of output voltage levels by adding switch components and DC input voltage sources. If it employs seven switches and three DC sources, the number of output voltage levels becomes seven. Although its THD characteristics are improved, it needs output filter to meet general output voltage THD requirement, i.e., 5 % below. By adding PWM switching schemes to the operation of the prior H-bridge switches, it can synthesize more sinusoidal waveform. By this simple alteration in the switching scheme, it can improve the output voltage THD requirement. To verify the high performance of the proposed switching scheme, Unipolar, Bipolar, Third harmonic based Pulse width modulation schemes are considered for analysis and computer-aided simulations are conducted using MATLAB.