Alamelu Nachiappan

Current controlled voltage source inverter using Hysteresis controller and PI controller

Current-controlled pulse width modulated (PWM) voltage source inverters are most widely used in high performance AC drive systems, as they provide high dynamic response. A comparative study between the Hysteresis controller and Proportional-Integral controller using PWM techniques for three-phase voltage source inverter was done. The comparison was done in terms of total harmonic distortion (THD) level at the three phase load current. Simulation was done with the help of Matlab-Simulink environment. The hysteresis controller provides gooddynamic performance, whereas the Proportional-Integral controller provides instantaneous current control and waveshaping, fixed inverter switching frequency resulting in better harmonics.

Q-learning based adaptive QoS routing protocol for MANETs

Mobile ad-hoc network (MANET) communication is challenging as they are dynamic in nature. We propose a MANET routing protocol considering the QoS (Quality of Service) parameters such as bandwidth efficiency, link stability and power metric. The idea of learning the network status information to enhance network routing is the key concept of our project. This helps to learn about the expiry of links and choose the path with more expiration time and the minimum power consumption. The learning is carried out instantly by a typical route request/reply packets containing the network status information. This reinforcement learning is called Q-Learning algorithm. The enhanced version of route determining process leads to tremendous improvement in QoS. We apply this learning algorithm in the existing MAODV protocol which will further enhance the QoS in MAODV. The simulation results show that the proposed system performs better than the existing system in terms of improving QoS.

Euclidean Distance Based Color Image Segmentation of Abnormality Detection from Pseudo Color Thermographs

514 Abstract—Infrared thermography, non-contact, noninvasive technique is widely accepted as a medical diagnostic tool. An IR camera captures heat variations from the skin and maps into thermographs. Thermographs are acquired for the whole body or the region of interest. Thermographs either gray scale or pseudo color are processed for abnormality detection and quantification. However temperature variations are not normally visible to naked eye. Hence it is necessary to develop and analyze the feature extraction algorithms for abnormality detection. This paper proposes Euclidean distance based color image segmentation algorithm for abnormality extraction. Pseudo color thermographs of arthritis, stress fracture, ankle injury and fracture are considered.

Hybrid routing and load balancing protocol for wireless sensor network

In wireless sensor network, when the nodes are mobile, the network structure keeps on changing dynamically, that is, new nodes enter the network and old members exit the network. As a result, the path from one node to the other varies from time to time. In addition, if the load on a particular part of the network is high, then the nodes will not be capable of transmitting the data. Thus, data delivery at the destination will be unsuccessful. Moreover, the part of the network involved in transmitting the data should not be overloaded. To overcome these issues, a hybrid routing protocol and load balancing technique is discussed in this paper for the mobile data collectors in which the path from source to destination is ensured before data transmission. The hybrid routing protocol that combines the reactive and proactive approach is used to enhance gradient based routing protocol for low power and lossy networks. This protocol can efficiently handle the movement of multiple sinks. Finally, load balancing is applied over the multiple mobile elements to balance the load of sensor nodes. Simulation results show that this protocol can increase the packet delivery ratio and residual energy with reduced delay and packet drop.

Agent based adaptive multicast routing with QoS guarantees in MANETs

The emergence of multimedia applications demands multicasting in MANETs. For such applications QoS provisioning is a complex and challenging issue. This paper proposes a QoS aware multicast routing scheme uses a set of static and mobile agents and ensures QoS guarantees in terms of bandwidth reservation, delay constraint, delay-jitter constraint and packet loss to multicast session. Here the mobile agents move around the network and collect the routing information. A hybrid method to support an adaptive multipath routing scheme under multiple QoS constraints is introduced. The scheme operates in the following steps. i) Clustering of nodes and then select the QoS aware cluster heads. 2) Identify and join multicast group members to the backbone. 3) Identify the intermediate nodes and discover multiple paths to satisfy the multiple constraints of a call. 4) Set up a QoS aware path for the required multicast route. 5) Maintain backbone and alternate paths in case of node mobility. Extensive simulations have been conducted to evaluate the performance of the proposed scheme in terms of packet delivery ratio, control overheads and node mobility. The simulation results show that the new scheme performs better than MAODV and ODMRP in terms of reduces the network overhead and improves packet delivery ratio.

A New Cluster Based Protocol for Wireless Sensor Networks

A new scheme that serves to find a routing path for Wireless Sensor Networks (WSNs), with a view to facilitate an increase in the network life time is proposed in this paper. It envisages the network to be in the form of clusters and develops an algorithm for transfer of information within the nodes and to the remote Base Station (BS). The approach involves the use of Ad-hoc On Demand Distance Vector (AODV) protocol and incorporates measures to accomplish an enhancement in the performance of the mobile networks. The NS-2 based simulation results are compared over a range of data with varying packet sizes for three different protocols to highlight the superiority of a Cluster based Ad-hoc On Demand Vector (CAODV) routing pattern for present day applications.

Fuzzy Cost Based Multicast Routing for Mobile Ad-Hoc Networks with Improved QoS

In this paper we describe an idea of selecting best paths from source to destination node in Mobile Ad-hoc Networks (MANETs ) using fuzzy cost. Here the multicast routing is carried out by selecting the most effective path in terms of minimum fuzzy cost by considering multiple independent QoS metrics such as bandwidth, end to end delay and number of nodes to transfer data from the source to the destination. In our method, the available resources of a path are converted into a single metric fuzzy cost. The fuzzy cost is calculated based on multi criterion objective fuzzy measure. The proposed fuzzy cost method is evaluated and compared with conventional protocol MAODV. Simulation results show that the proposed system performs better than the conventional MAODV in terms of improving packet delivery ratio and minimizing the end to end delay. The proposed multicasting protocol is simulated using the NS-2, while the fuzzy cost is calculated using Matlab.

Abnormality Detection from Medical Thermographs in Human Using Euclidean Distance Based Color Image Segmentation

Infrared thermography is recently widely accepted as a medical diagnostic tool. Thermographs are acquired for the whole body or the region of interest. Thermographs are processed for abnormality detection and quantification. As temperature variations are not normally visible to naked eye it is necessary to develop and analyze the feature extraction algorithms for abnormality detection. This paper proposes Euclidean distance based color image segmentation algorithm for abnormality extraction. Arthritis and stress fracture thermographs are considered

Selective harmonic elimination PWM method using two level inverter by differential evolution optimization technique

The Objective of the paper is to reduce the harmonic order such as 5th, 7th, 11th, 13th, 17th, 19th and 23rd. The triplen harmonic like 3rd, 9th, 15th, 21st are eliminated naturally by three phase inverter. The proposed waveform is symmetric so that all even order harmonics will be eliminated. In order to reduce lower order harmonics, differential evolution optimization technique is used to find the optimized firing angles. Using the optimized firing angle, an inverter firing circuit is designed and the FFT analysis is carried out. The analysis and simulation of the three phase inverter is done in MATLAB, Using the optimized firing angles obtained from the differential evolution.

Extraction and quantification techniques for abnormality detection from medical thermographs in human

Nowadays Infrared thermography is widely accepted as a medical diagnostic tool. Thermographs are acquired for the whole body or the region of interest. Thermographs are processed for abnormality detection and quantification. As temperature variations are not normally visible to naked eye it is necessary to develop and analyze the feature extraction algorithms for abnormality detection. This paper analyzes the performance of three feature extraction algorithms used for abnormality detection. The developed techniques are applied on Arthritis and stress fracture thermographs.