Shoab A. Khan

Automated detection of exudates and macula for grading of diabetic macular edema

Medical systems based on state of the art image processing and pattern recognition techniques are very common now a day. These systems are of prime interest to provide basic health care facilities to patients and support to doctors. Diabetic macular edema is one of the retinal abnormalities in which diabetic patient suffers from severe vision loss due to affected macula. It affects the central vision of the person and causes total blindness in severe cases. In this article, we propose an intelligent system for detection and grading of macular edema to assist the ophthalmologists in early and automated detection of the disease. The proposed system consists of a novel method for accurate detection of macula using a detailed feature set and Gaussian mixtures model based classifier. We also present a new hybrid classifier as an ensemble of Gaussian mixture model and support vector machine for improved exudate detection even in the presence of other bright lesions which eventually leads to reliable classification of input retinal image in different stages of macular edema. The statistical analysis and comparative evaluation of proposed system with existing methods are performed on publicly available standard retinal image databases. The proposed system has achieved average value of 97.3%, 95.9% and 96.8% for sensitivity, specificity and accuracy respectively on both databases.

Robust image matching algorithm

Image matching is an important task. There are many available methods for occluded image matching, e.g., Hausdorff distance and wavelet transform based matching. In this paper we propose new simple image-matching algorithm, robust image matching algorithm (RIMA), an extension to distance transform (chamfer) matching. Distance transform and conventional chamfer matching algorithm are explained. Different matching measures for RIMA are presented. Examples to demonstrate the algorithm and necessary results are also included. Proposed RIMA is time efficient, robust, rotation, scale and perspective invariant method.

Adding Security against Packet Dropping Attack in Mobile Ad Hoc Networks

Mobile ad hoc networks are collection of wireless mobile nodes forming a temporary network without the aid of any established infrastructure. Security issues are more paramount in such networks even more so than in wired networks. Despite the existence of well-known security mechanisms, additional vulnerabilities and features pertinent to this new networking paradigm might render the traditional solutions inapplicable. In particular these networks are extremely under threat to insider attacks especially packet dropping attacks. It is very difficult to detect such attacks because they comes in the category of attacks in mobile ad hoc networks in which the attacker nodes becomes the part of the network. In this paper we have proposed a two folded approach, to detect and then to isolate such nodes which become the part of the network to cause packet dropping attacks. First approach will detect the misbehavior of nodes and will identify the malicious activity in network, and then upon identification of nodes misbehavior in network other approach will isolate the malicious node from network.

Wavelet based palmprint authentication system

Palmprint based personal verification has quickly entered the biometric family due to its ease of acquisition, high user acceptance and reliability. This paper proposes a palm print based identification system using the textural information, employing different wavelet transforms. The transforms employed have been analyzed for their individual as well as combined performances at feature level. The wavelets used for the analysis are Biorthogonal, Symlet and Discrete Meyer. The analysis of these wavelets is carried out on 500 images, acquired through indigenously made image acquisition system. 500 palmprint obtained from 50 users with 10 samples each have been collected over a period of six months and have been evaluated for the performance of the proposed system. The experimental results obtained from the data have demonstrated the feasibility of the proposed system by exhibiting Genuine Acceptance Rate, GAR of 97.12%.

Urdu online handwriting recognition

Handwriting has continued to persist as a mean of communication and recording information in day-to-day life even with the introduction of new technologies. Handwritten information can be used as computer input once it is converted to digital form. This paper focus on Urdu online handwriting recognition system that converts user hand written information into Urdu text. The working of recognition system is based on analytical approach to segmentation for feature extraction, rule based slant analysis for slant removal and tree based dictionary search for classification. The proposed tree search technique reduces the search space up to 96.2% and is therefore significantly faster than searching techniques, in which we have to process the whole dictionary to come up with the correct answer

A feature level multimodal approach for palmprint identification using directional subband energies

Palmprint based personal identification has gained preference over other biometric modalities due to its ease of acquisition, high user acceptance and reliability. This paper presents a palmprint based identification approach which uses the textural information available on the palmprint by employing a feature level fusion of contourlet transform (CT) and non-subsampled contourlet transform (NSCT). The proposed algorithm captures both local and global details in a palmprint as a compact fixed length palm code. After establishing the region of interest (ROI), the two-dimensional (2-D) spectrum is divided into fine slices using iterated directional filterbanks. Next, directional energy component for each block from the decomposed subband outputs is computed separately for the two transforms. The features from both domains are then fused at feature levels. Palmprint matching is then performed using normalized Euclidean distance classifier. The algorithm is tested on complete database of 7752 palm images of Polytechnic University of Hong Kong, and 500 palm images of GPDS Hand database from University of Las Palmas de Gran Canaria. The experimental results were compiled for features based upon individual transforms and fused one. CT based approach demonstrated the decidability index of 2.7734 and equal error rate (EER) of 0.2333% while NSCT based approach depicted decidability index of 2.8125 and EER of 0.1604% on palm database of Polytechnic University of Hong Kong. Similarly, CT based approach demonstrated the decidability index of 2.6212 and equal error rate (EER) of 0.7082% while NSCT based approach depicted decidability index of 2.7278 and EER of 0.5082% on GPDS hand database. The multimodal approach based upon feature fusion achieved decidability index of 2.8914 and EER of 0.1563% on database of Polytechnic University of Hong Kong and decidability index of 2.7956 and EER of 0.3112% on GPDS hand database. The quantitative measures confirm progressive improved results in three approaches for both the databases.

Inductive link design for medical implants

This paper describes design principles to design and develop a transcutaneous link for medical implants using inductively coupled coils. Parameters which optimize link efficiency have been discussed in the light of previous studies and a simple design methodology to find optimized parameters for Class E amplifier and inductive coils is outlined. Paper also describes design of an indigenously developed transcutaneous link from commercial off-the-shelf components to demonstrate the design process. Simulation and practical results of the link developed at 2.5MHz for 100mW output power are provided. We were able to achieve 40% link efficiency with data rate of 128kbps from laboratory-based discrete electronic components.

FIR filter design methodology for hardware optimized implementation

This paper presents a novel method of FIR filter design for optimized hardware implementation. The FIR filters are extensively employed in a variety of consumer devices like TVs, mobile phones and docking stations. The optimized implementations of FIR filter furnish high quality signal processing at reasonable cost. The paper first analyzes the effects of quantization on frequency response of a filter by successively reducing the number of bits in each coefficient. Empirical analysis of coefficient quantization reveals a relationship between the number of bits, number of coefficients and the frequency response. The paper then presents a methodology for an optimized design of an FIR filter for hardware implementation. The proposed approach first designs a filter with certain parameters and then redesigns the same filter with tighter constraints resulting in higher filter order. The coefficients of the improved or over designed filter are then quantized successively with lesser number of bits by an iterative algorithm to a level where its frequency response matches to the original requirements. The synthesis results show that a significant reduction in hardware resources can be achieved using this methodology. The proposed approach has so far not been reported for reduction in hardware resources.

Pseudo Randomized Sequence Number Based Solution to 802.11 Disassociation Denial of Service Attack

Wireless local area networks (WLAN) provide network connectivity and flexibility at a very low cost. Last two decades have seen the exponential growth in this area. Institute of Electrical and Electronics Engineers (IEEE) ratified IEEE standard 802.11 in 1999, which is the defacto wireless standard. Security flaws were soon detected in this standard, and as a result amendments / enhancements were introduced. IEEE 802.1 li a security enhancement, was ratified in 2004. It was designed to address wireless security issues however it also has some flaws and fails to achieve desired objectives especially availability. Unauthenticated management and control frames open the vulnerability of identity theft and are the main cause of Denial of Service (DoS) attacks. Spoofed disassociation messages can successfully be used to launch DoS attacks. In this paper we have explained the Spoofed disassociation DoS attack and proposed a robust solution to this attack.

Cognitive communication device for vehicular networking

This paper presents intelligent Communication protocols for universal access in a proposed Vehicular Networking Device. The device can communicate on multiple frequency bands using different MAC and PHY Interfaces. The device cannot use existing routing protocols as they are limited and work in relation with a unique MAC and PHY Interface. This paper presents the communication protocols and vehicular device that extends the routing protocols to work as a Cognitive layer over multiple MAC and PHY Interface for optimum connectivity, seamless switching and Quality of Service parameters. The device is tested with three extended routing protocols AODV-MI, GOLSR-MI and SORP. The device incorporates integrated multi telecommunication technologies like GSM, Satellite, VHF, UHF, HF, Broadband Wireless and wired links.