International Journal of Research in Science & Technology

1-7

Authors: 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.

8-12

Authors: A.Vineela and L. Sudha Rani

The Internet of Things (IoT), also referred to as the Internet of Objects, will change everything—including 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.

19-25

Authors: 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.

36-44

Authors: 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

5

Authors: 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.

12-15

Authors: 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.

22-27

Authors: 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.

4

Authors: 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.

5

Authors: S.Rahumath Beevi, A.Subanth Williams and L.Yousuf Siddique

The Grid connected PV system requires a proper voltage control controller. In this paper an efficient voltage control by using slide mode controller with Maximum Power Point Tracking (MPPT) is presented. The voltage command is determined by the PV panel. Here the sliding mode controller is designed so as to balance the power flow from PV panel to the grid and load such that the PV power is utilized effectively. The design and simulation using MATLAB is presented in this work.

34-39

Authors: R.K. Jati, S.K.Paikray and U.K.Misra

In this paper we have established a theorem on the local Property of summability of factored Fourier series.

1-4

Authors: 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.

9-15

Authors: 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.

20-24

Authors: 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.