Vignan University

About: Vignan University is a education organization based out in Guntur, Andhra Pradesh, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 1138 authors who have published 1381 publications receiving 7798 citations.

Investigation on intelligent controllers performace used in electric vehicle application

Abstract: The main objective of this work is to design a control strategy of a hybrid energy storage system (HESS) to switch the battery and ultracapacitor (UC) as per EV requirement. To achieve the objectiv...

Synthesis and Characterization of Compounds Potentially Related to the Janus Kinase Inhibitor Baricitinib

Abstract: Nine compounds potentially related to the Janus kinase inhibitor Baricitinib have been identified, synthesized by conventional methods, and characterized by IR, 1H and 13C NMR, and mass spectral data.

GPS-enabled collaborative sensing in cognitive radio networks for efficient spectrum assignment

Abstract: Accurate sensing of the spectrum is one of the prime requirements for efficient functioning of cognitive Radio systems. But accurate sensing is a complex process, as signals of different modulations, coding methods and power levels along with fading and noise are present in the given radio environment. Collaborative sensing techniques can help to improve the sensing accuracy. One such collaborative sensing mechanism is proposed in this work where several cognitive radios having GPS capability contribute to the database of ‘spectrum occupancy’, corresponding to the sensing information at various Geographic locations. The secondary users that want to avail the spectrum obtain this information from the server and analyze the environment by combining this information with the locally sensed information. This method can help to implement efficient spectrum assignment strategies to cognitive radios. A scenario where such information from the database is used to optimize the bandwidth utilization at a given geographical location, is explored in this work. The simulation results of the system show that the proposed mechanism can help to improve the throughput of secondary network.

Improved internal model controller design to control speed and torque surges for wind turbine driven permanent magnet synchronous generator

Abstract: The paper compares proportional and Integral (PI) controller based Permanent Magnet Synchronous Generator (PMSG) with improved Internal Model Controller (IMC). The accuracy of speed and torque control of PMSG depends on generator speed control and current control parameters. IMC is an efficient method by which speed of the generator can be controlled efficiently and quickly by reducing surges due to disturbances. There are two current control loop, which are regulated by PI controllers. In this paper, improved feed forward based first order IMC is designed and this is further modified with tuned with second order IMC system. The issues like torque and current surges and speed maintenance during transients were analyzed. Sensible and faster control can be achieved with proposed scheme and also can overcome above torque and current surges the transient behavior of PMSG was tested fewer than two sub-cases like constant generator speed and variable wind speed and constant wind speed and variable generator speed. Results shows that proposed control technique can suppress torque ripples and surges during disturbances than with PI controller. The simulation analysis study was done using MATLAB/ SIMULINK.

Novel on chip-interconnection structures for giga-scale integration VLSI ICS

Abstract: Based on the guidelines of International Technology Roadmap for Semiconductors (ITRS) Intel has already designed and manufactured the next generation product of the Itanium family containing 1.72 billion transistors. In each new technology due to scaling, individual transistors are becoming smaller and faster, and are dissipating low power. The main challenge with these systems is wiring of these billion transistors since wire length interconnect scaling increases the distributed resistance-capacitance product. In addition, high clock frequencies necessitate reverse scaling of global and semi-global interconnects so that they satisfy the timing constraints. Hence, the performances of future GSI systems will be severely restricted by interconnect performance. It is therefore essential to look at interconnect design techniques that will reduce the impact of interconnect networks on the power, performance and cost of the entire system. In this paper a new routing technique called Wave-Pipelined Multiplexed (WPM) Routing similar to Time Division Multiple Access (TDMA) is discussed. This technique is highly useful for the current high density CMOS VLSI ICs. The major advantages of WPM routing technique are flexible, robust, simple to implement, and realized with low area, low power and performance overhead requirements.