Electrical and Electronics

In a recent years, security for the thermal images are more necessary due to fast growing information technology. Here proposed an thermal image encryption based on histogram diffusion and permutation using chaotic map. As we know that histogram of thermal image distributed towards right (towards white pixel) and towards left (towards black). First step of proposed algorithm shift the histogram by mixing a random number. After that resultant image undergo permutation process with the help of chaotic map followed block wise histogram diffusing. In next level, apply the bit plane permutation. At last XOR operation with random image to get thermal encrypted image. The simulation results shows that proposed algorithm achieves high security.

A variable frequency and variable phase function generator with three outputs of (1) reference f_O (2) lead phase f_O + Æ₁ and (3) lag  phase f_O - Æ₂, is described in this paper. The leading phase difference Æ₁ is continuously adjustable over 0 to 180^o by an input control voltage V_C1 and the lagging phase difference Æ₂ is also continuously adjustable over 0 to -180^o by an another input control voltage V_C2, independent of frequency of operation of the function generator which can be set by a third control input dc voltage –V_I

Nowadays Hospital requirements are needed to be automated. During surgery, manual handling of surgical instruments may lead to human error. Here an automated surgical instrument lifting system is proposed and its movement carried over in four directions. System responds to voice and sensor signal from android accelerometer for controlling the motors connected with Microcontroller. Lifting of surgical instrument is done by a movable round table that rotates in a circular motion then a robotic arm lifts the surgical instruments using MATLAB software and Microcontroller hardware. Doctor’s voice command also used for executing the system.

In this work, a novel power conversion structure for grid-connected photovoltaic applications is presented. This structure is based on a Diode clamped multilevel inverter. The configuration of the PV system is based on the multi-string technology and the maximum power point is obtained using PSO Algorithm. The output of the MPPT tracker controls the duty cycle of the boost converter. To control this power converter, SVPWM based modulation technique is implemented. The proposed system operation was simulated using the MATLAB/Simulink power system toolbox and are furnished to verify the efficiency of this method.

L1-minimization solves the minimum L1-norm solution to an underdetermined linear system. It has recently received much attention, mainly motivated by the new compressive sensing theory that shows that under certain conditions an L1-minimization solution is also the sparsest solution to that system. In this paper an L1 minimization algorithm is proposed for solution of Dual Tone Multiple Frequ-ency (DTMF) reconstruction problems. In the method of Compressive sensing, a raw signal or image can be regarded as a vector which can be represented as a linear combination of certain basis functions. The discrete cosine transform (DCT) has been used as the basis function in the proposed algorithm. This algorithm considers only 500 samples and reconstructs the original signals exactly without any distortion. The compressed DTMF signal is estimated using DTMF decoder with the help of Goertzel algorithm, the popularity of which lies in the small number of points at which the DFT is estimated. We compare with the existing algorithms such as FFT and Goertzel algorithms. The results show the effectiveness of the proposed algorithm.

This paper presents comparative study and simulation results for different Hybrid Multilevel Inverter configurations. This paper covers hybrid multilevel inverters such as cascaded multilevel inverter with high voltage low-frequency pulse width-modulation (PWM) and low voltage high frequency pulse width-modulation (PWM) and series connected half-bridge modules hybrid multilevel inverters. Here the operating principle of each topology is discussed with a review of the relevant modulation method focusing mainly on total harmonic distortion (THD). Such multilevel inverters achieve higher power quality with a given switch count when compared to traditional multilevel inverters. The purpose of the circuits presented here is to minimize the reverse voltage stress that affects the power switches and decrease the harmonic distortion of the voltage applied to the load.

The paper proposed the application of a new four-dimensional hyper chaotic map based on the Lorenz chaotic system to realize chaotic encryption for improved security. Hyper chaotic systems are more complex and difficult to predict. An image encryption algorithm is designed by utilizing the basic operations like permutation, confusion and diffusion. The combination of the user defined 256 bits secret key and the plain image are used as initial conditions for the 4D hyper-chaotic system to generate the key matrix. Several test images are used for inspecting the validity of the proposed work. The security analyses and computer simulations on the basis of key space analysis, statistical analysis, histogram analysis, information entropy analysis, correlation analysis and differential analysis is done. The NPCR and UACI values of encrypted images are also calculated. The result shows that a single bit change in the pixel value of the input plain images will cause a significant changed in the ciphered images. Total key space for the proposed method is 2256, which is good enough to protect the encrypted image against brute-force attack.

In the present scenario, availability of power and water are insufficient to satisfy the farmer’s requirements. Traditionally implemented Techniques of irrigation are proving to be less futile as these are not good at multitasking different concerns which are combinations of availability of water, source of energy and timely soil profile analysis. With the merger of automation and the methods of irrigation used earlier. The scope to mitigate issues concerning water and power crisis, is huge. In this paper Internet of Things based solar powered smart irrigation system with monitoring and control features, is designed and implemented. The sensor enabled proposed model of smart irrigation system along with its Android application and ESP8266 as its main controllers. The farmland parameters can be monitored anywhere around the world with the help of IoT technology. The whole concept of this paper is implemented and then only the results are presented.

The effects of distributed generation in the Nigerian North East zone is discussed in this paper. DG capacity installation in the power system was modelled using NEPLAN software. Network loss reduction, reduction in transmission line losses and congestion as well as voltage profile improvement for the nodes of the network were some of the observed advantages in the results.

This paper has presented a control strategy for improving transient response performance for a plastic extrusion process.. A dynamic equation of a single screw plastic extruder was obtained. The main control variable is the screw speed in relation with the pressure and the temperature. A high degree of speed accuracy is required to ensure the optimal performance of the extrusion process. In order to adequately control the screw speed in relation to the pressure, a model reference adaptive control (MRAC) which combines a proportional integral and derivative (PID) control strategy was developed and integrated with obtained dynamic equation of a single screw plastic extrusion process considered in this context. The gain parameter of the MRAC was selected for different values and simulations were performed in Matlab/Simulink environment by altering the adaptive gain. The implemented system in Matlab/Simulink shows that the developed controller improved the transient response performance of the process. This resulted to a fast response, near zero-overshoot, and improved transient performance.