M. Sabrigiriraj

VLSI implementation of a new LMS-based algorithm for noise removal in ECG signal

ABSTRACT Least mean square (LMS)-based adaptive filters are widely deployed for removing artefacts in electrocardiogram (ECG) due to less number of computations. But they posses high mean square error (MSE) under noisy environment. The transform domain variable step-size LMS algorithm reduces the MSE at the cost of computational complexity. In this paper, a variable step-size delayed LMS adaptive filter is used to remove the artefacts from the ECG signal for improved feature extraction. The dedicated digital Signal processors provide fast processing, but they are not flexible. By using field programmable gate arrays, the pipelined architectures can be used to enhance the system performance. The pipelined architecture can enhance the operation efficiency of the adaptive filter and save the power consumption. This technique provides high signal-to-noise ratio and low MSE with reduced computational complexity; hence, it is a useful method for monitoring patients with heart-related problem.

Fault detection and recovery scheme for routing and lifetime enhancement in WSN

In WSNs, failures are unavoidable due to the inhospitable environment and unattended deployment. The node failure leads to disconnection from the network and causes network partitioning. We propose to develop a fault detection and recovery scheme where the sink generates an agent packet and the Agent forms a query path towards the dead or faulty node. Here, sink periodically broadcasts the Agent packet to all its neighbor nodes. The receiving node randomly makes a decision as whether to forward the packet or not thereby detecting the dead or faulty nodes. After detecting a node failure or dead node, the connectivity is restored using Least-Disruptive Topology Repair (LeDiR) without extending the length of the shortest path among nodes compared to the pre failure topology. LeDiR replaces the faulty node with block movement.

Palm and hand vein-based fuzzy vault generation scheme for multibiometric cryptosystem

Abstract Template security of biometric systems is a vital issue and needs critical focus. The importance lies in the fact that unlike passwords, stolen biometric templates cannot be revoked. Hence, the biometric templates cannot be stored in plain format and needs strong protection against any forgery. In this paper, we present a technique to generate face and palm vein-based fuzzy vault for multi-biometric cryptosystem. Here, initially the input images are pre-processed using various processes to make images fit for further processing. In our proposed method, the features are extracted from the processed hand and palm vein images by finding out unique common points. The chaff points are added to the already extracted points to obtain the combined feature vector. The secret key points which are generated based on the user key input (by using proposed method) are added to the combined feature vector to have the fuzzy vault. For decoding, the multi-modal biometric template from palm vein and hand vein image is constructed and is combined with the stored fuzzy vault to generate the final key. Finally, the experimentation is conducted using the palm vein and hand vein database. The evaluation metrics employed are FMR (False Match Ratio) and GMR (Genuine Match Ratio). From the metric values obtained for the proposed system, we can infer that the system has performed well. The results are also compared to our earlier technique and the results shows that the proposed technique has achieved better results having GAR of 94% without noise and 88% with noise.

Wavelength assignment for all-to-all broadcast in WDM optical linear array with limited drops

All-to-all broadcast is to disseminate a unique message from each node to every other node. This is a fundamental problem in multiprocessor systems and telecommunication networks that need to collect information about other nodes in the network regularly in order to manage network resources efficiently. In this paper, a novel wavelength assignment method is proposed to establish all-to-all broadcast in a linear array network. The network model is an all-optical network, in which a message from source node can be dropped (or split) only at a limited number of destination nodes along a light path due to power loss of dropping optical signals. The minimum number of wavelengths required to establish all-to-all broadcast is also derived for a linear array network.

Wavelength Assignment for All-to-All Broadcast in Wavelength Division Multiplexing Optical Ring

Abstract A novel wavelength assignment method is proposed for a bidirectional WDM ring network and the minimum number of wavelengths required to support all-to-all broadcast is determined. The new method can assign each wavelength directly and simultaneously to a group of non-overlapping connections on an N-node ring without the aid of any table or matrix. The presented wavelength assignment method is much faster than other direct methods with explicit formulas previously reported for WDM ring network.

All-to-all broadcast in optical WDM networks under light-tree model

This paper addresses the problem of wavelength requirements for all-to-all broadcast communication in wavelength division multiplexed optical networks. The network model is an all-optical network, in which a message can be split and dropped to all destination nodes along a light-tree. A tight bound on the minimum number of wavelengths required to establish all-to-all broadcast communication for various topologies is presented. The optimal routing and wavelength assignment algorithms for all-to-all broadcast to achieve the minimal number of wavelengths are also described for these topologies

An Efficient Wavelength Assignment for all-to-all Broadcast in Optical WDM Hypercube Network

Wavelength-division multiplexing (WDM) optical networks provide huge bandwidth by allowing multiple data strams transmitted simultaneously along the same optical fiber, with each stream assigned a distinct wavelength. An important issue in optical WDM networks is to minimize the number of wavelengths required for communication. All-to-All broadcast is a fundamental communication application on computer/communication networks. In this paper, we provide the method of assigning wavelengths for all-to-all broadcast communication in optical WDM hypercube network without light splitters under e-cube routing algorithm. We also find the minimum number of wavelengths required to support all-to-all broadcast communication.

Embedding of iris data to hand vein images using watermarking technology to improve template protection in biometric recognition

Biometric recognition is noteworthy method for recognition of person in recent years. Here, a common concern is biometric security which is the privacy issues derived from storage and misuses of the template data. In order to handle this issue, researches have proposed different algorithms to be confronted by security of biometric systems. Two major ways are, (1) Encryption, and (2) watermarking by securing biometric images and templates. In this paper, we utilise a watermarking technology to improve the template security in biometric authentication. According to, two modalities such as, iris and hand vein is taken to preserve the characteristics of liveliness and permanency. Our proposed technique for embedding of iris data to hand vein images using watermarking technology to improve template protection in biometric recognition is done based on the following steps, i) pre-processing of iris and hand vein images, ii) iris template extraction, iii) Vein extraction, iv) Embedding of iris pattern to vein images based on region of interest, v) Storing embedded images. In the recognition phase, iris pattern is extracted from the embedded image and then, matching is done with query images. The final decision of authentication is done based on the product rule-based score level fusion. The implementation is done using MATLAB and the performance of the technique is analysed with FAR, FRR and accuracy.

Real-Time Implementation and Performance Evaluation of Brain Emotional Learning Developed for FPGA-Based PMBLDC Motor Drives

Much research is taking place in the field of motor drives, especially in the area of permanent magnet brushless DC motors (PMBLDC).This paper dealt with developing a Simulink model for PMBLDC motor drive systems with a high-performance, improved brain emotional-learning based intelligent controller (IBELBIC) using MATLAB/Simulink to control the speed and torque of the machine. To enhance the performance of PMBLDC motor, two control loops were employed for control of current and speed, respectively. Though the conventional PI controller may be used to control the speed of PMBLDC motor, the stability of the machine under changing loads cannot be ensured. Therefore, IBELBIC with a tracking system for the speed loop is proposed in this paper. It has been ascertained for the first time that the speed and torque performance of the system is enhanced by IBELBIC with minimum processing time. The contribution of this novel IBELBIC in improving the control system performance is shown by comparison with results obtained from classic PI controller, fuzzy PI controller, anti-windup PI controller, and IBELBIC. The results suggested that IBELBIC-based PMBLDC motor drive was more versatile for variable speed applications. The validation of the simulation was provided by a 400 W PMBLDC motor and drive system using Spartan 3 FPGA (Field Programmable Gate Array) based prototype, which is generally suitable for dedicated implementations of design and ease of redesign. The LABVIEW-based customized program was developed on a computer to monitor the motor performance.

Multihop All-to-all Broadcast in WDM Optical Hypercube and Cube-connected Cycle

Abstract All-to-all broadcast is to disseminate a unique message from each node to every other node in the network. This is a fundamental problem in multiprocessor systems and telecommunication networks that need to collect information about other nodes in the network regularly in order to manage network resources efficiently. This paper addresses the problem of all-to-all broadcast communication in wavelength-routed optical hypercube and cube-connected cycle networks under multihop routing. In a multihop routed network, a message undergoes multiple Optical-Electrical-Optical conversions before reaching its destination. The multihop intermediate nodes (except the source and destination nodes) of a lightpath convert the optical signal into electrical signal, process the message, and then convert the message back to the optical form to transmit in the next optical hop. An optical hop is a continuous lightpath with no wavelength conversion. An upper bound on the number of wavelengths required to establish all-to-all broadcast is derived for hypercube and cube-connected cycle networks under multihop routing.