M Tech Dissertations

Permanent URI for this collectionhttp://drsr.daiict.ac.in/handle/123456789/3

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  • ItemOpen Access
    New learning based super resolution using contourlet transform
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Singh, Vineet P.; Joshi, Manjunath V.
    new learning based super-resolution reconstruction using contourlet transforms is proposed. contourlet transform provides high degree of directionality. It captures geometrical smoothness along multiple directions and learns the edges present in an image normal to the contour. For learning purpose, training set of low resolution (LR) and high resolution (HR) images, all captured using the same camera, are used. Here two and three level contourlet decomposition for LR images (test image and training image dataset) and HR training images respectively. The comparison of contourlet coeffcients of LR test image from the LR training set using minimum absolute difference (MAD) criterion to obtain the best match contourlet coeffcient. The finer details of test image are learned from the high resolution contourlet coefficients of the training data set. The inverse contourlet transform gives super resolved image corresponding to the test image.
  • ItemOpen Access
    Vehicle detection and tracking
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Rao, K. Ramprasad; Joshi, Manjunath V.
    Real time trafficc monitoring is one of the most challenging problems in machine vision. This is one of the most sorted out research topic because of the wide spec-trum of promising applications in many areas such as smart surveillance, military applications, etc. We present a method of extracting moving targets from a real-time video stream. This approach detects and classifies vehicles in image sequences of trafficc scenes recorded by a stationary camera. Our method aims at segregating cars from non-cars and to track them through the video sequence. A classication criteria based on the features is applied to these targets to classify them into categories: cars and non-cars. Each vehicle can be described by its features. The template region is estimated by means of minimum distance approach with respect to centroid of the obtained blob of the target. Extraction of features from each frame ensures eefficiency of the tracking system.
  • ItemOpen Access
    Particle swarm optimization based synthesis of analog circuits using neural network performance macromodels
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Saxena, Neha; Mandal, Sushanta Kumar
    This thesis presents an efficient an fast synthesis procedure for an analog circuit. The proposed synthesis procedure used artificial neural network (ANN) models in combination with particle swarm optimizer. ANN has been used to develop macro-models for SPICE simulated data of analog circuit which takes transistor sizes as input and produced circuit specification as output in negligible time. The particle swarm optimizer explore the specfied design space and generates transistor sizes as potential solutions. Several synthesis results are presented which show good accuracy with respect to SPICE simulations. Since the proposed procedure does not require an SPICE simulation in the synthesis loop, it substantially reduces the design time in circuit design optimization.
  • ItemOpen Access
    Executable specification design and simulation of OFDM based communication system
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Sa, Sudhir Kumar; Dubey, Rahul
    The communication system using the OFDM principle is today one of the most important application in communication field. This system has various applications from broadband to 3G and digital TV to Radio LANs. This master’s thesis project deals with the implementation of certain specification, algorithmic exploration for WVAN (wireless video area network) in Simulink®. The implemented model and its specification is the reference for the hardware designing and verification. The model used in OFDM based QPSK/16-QAM modulated communication system for the WHD WVAN standard at the High Rate Physical (HRP) layer. This thesis project describes the functionality of the various communication blocks and the method of data transmission through these blocks. The main purpose of this model is to calculate the BER (Bit Error Rate). The final design which supports the different HRP mode for different code rate and different Modulation scheme can take different length of sub-packets which depends on the HRP mode of Transmission. This model also implements the radix-2 FFT algorithm for fixed point FFT processor. Since the FFT processor cannot be used standalone, so in this thesis it is employed in an OFDM Transmitter and Receiver. The goal of this report is to outline the knowledge gained during the master’s thesis project, to describe a design methodology for the OFDM based communication system for high throughput and best error protection. The functionality of each block of the communication system is written in „C‟ code and the output data of each block of Simulink Model is compared to 'C' code written output for the same input.
  • ItemOpen Access
    Path complexity of the class binary search tree
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Doshi, Nishant; Amin, Ashok T.
    Path complexity of a program is defined as the number of program execution paths as a function of input size n. This notion of program complexity has been extended to complexity of a class as follows. Class had data members and data operations. The notion of state for the class is defined based on structural representation of a class. We are assuming only those data operations that change state of a class. The path complexity of a class is defined to be the number of valid input sequences, each of them containing n data operations. We have analyzed the path complexity of the class Binary Search Tree (BST) based on the algorithms for insert and delete data operations. Later we modify program for delete operation to facilitate determination of path complexity for the class BST. The bounds for the path complexity of the class BST are determined. A program is developed to obtain path complexity of the class BST.
  • ItemOpen Access
    Testbed based experimental analysis of transport protocols over wireless ad hoc networks
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Shah, Harshil Anilkumar; Srivastava, Sanjay
    Ad hoc networks are networks with no infrastructure and self-organized in nature. ad hoc networks allow nodes to form network when they come into range of each other provided nodes are configured in ad hoc mode. But these types of network are challenges like high bit error rates, route failures due to mobility, high noise, signal fading and low speed etc. to deal with. Due to this, protocols which are widely used in traditional wired networks may not perform well in MANETs. lower layers like MAC and network layer are either completely changed like 802.11 instead of 802.3 at MAC layer and introducing reactive routing protocols instead of only proactive routing at network layer or significant improvement schemes have been proposed for wireless networks in the existing legacy wired network protocols. But transport layer in MANET is mostly similar to wired networks except some improvements like TCP-ELFN and TCP-Feedback and new transport protocols like Ad hoc-TCP (ATCP), Transport Protocol for Ad hoc networks (TPA) and Ad-hoc Transport Pro- tool (ATP).performance degradation of TCP over wireless links is mainly due to wireless characteristics, TCP features like self-clocking, loss based congestion control, coupling of congestion and reliability, slow start. Several studies have been carried out to evaluate performance of TCP over MANETs but most of them are simulation based studies. But as simulation scenarios can not model exactly the unpredictable nature of wireless environment, we have decided to analyze performance of trans- port protocols over experimental test bed which can be more accurate evaluation of protocols in real-life situation. Performance of 2 transport protocols is analyzed.
  • ItemOpen Access
    Design and implementation of 128-point fixed point streaming FFT processor for OFDM based communication system
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Verma, Sunil Kumar; Dubey, Rahul
    Fast Fourier Transform (FFT) processors are today one of the most important blocks in communication systems. They are used in every communication system from broadband to 3G and digital TV to Radio LANs. This master’s thesis project deals with the pipelined, radix-2 algorithmic exploration and the hardware solution for the FFT processor with the FFT size of 2N points, the selection of the scaling schemes based on application requirement is discussed. The designed architecture is functionally verified in Simulink® and the Xilinx® ISE simulator. How to encapsulate the C++ coded algorithms or functions into the Simulink. This FFT processor is used in OFDM based BPSK modulated communication system for the WHD WVAN standard at the Low Rate Physical (LRP) lay. This thesis project presents the design of the 128 point fixed–point F streaming processor. The final architecture used is the SDF (single path with delay feedback) that implements the radix-2 FFT algorithm. Since the FFT processor can’t be used standalone, so in this thesis it is employed in an OFDM Transmitter and the performance is measured for SNR over a range of PAPRs. The goal of this report is to outline the knowledge gained during the master’s thesis project, to describe a design methodology for the fixed point pipelined FFT processors, the scaling choices and how to encapsulate the existing C code into the Simulink environment to measure the performance of fixed-point systems.
  • ItemOpen Access
    Cache performance evaluation in DSR protocol through cross-layering for mobile ad hoc networks
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Sharma, Kapil; Sunitha, V.
    Wireless mobile ad-hoc networks are being actively studied by many researchers these days. These networks are suitable to be used in various situations because of (i) their infrastructure-less property and (ii) the mobility of the nodes of the network. However, it is these features which give rice to problems in study of such networks. Further, routing is one of the basic issues in any network design. Inclusion of moving capability to the nodes, make the routing problem more complicated. One is always interested in increasing the throughput and reducing overhead while at the same time solving the issues related to routing. DSR is a protocol that is extensively used for routing in such networks. Cache management and route caching play a significant role in using DSR successively to attain the best behavior for these networks. This thesis looks at and suggests some methods for route caching in DSR.
  • ItemOpen Access
    Cooperation enforcement mechanisms in wireless adhoc networks
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Chaturvedi, Manish Shivshankar; Srivastava, Sanjay
    Wireless adhoc networks are autonomous, infrastrutureless networks where there are no dedicated routers or base stations and nodes are expected to cooperate in Wireless performing routing duties to keep network connected. Cooperation can be assumed if all nodes belong to single authority (e.g. military service or disaster management). But in applications where nodes do not belong to single authority and have limited resources (energy of battery driven devices), like pervasive computing or ubiquitous computing environment, one can not deny possibility of node selfishness. Also as there is no central authority to control node behavior, one can not deny possibility of node maliciousness. Many cooperation enforcement schemes are proposed in literature, and every scheme is shown to perform better under its own set of assumptions. These assumptions are different for different schemes. So, we aim at defining common set of assumptions and comparing selected schemes on this common ground with respect to packet delivery ratio, energy consumption, routing and other control overhead. We find that with the traffic scenario where nodes do not need services of one another at the same time, the cooperation schemes are not effective in dealing with node selfish ness. We also find that, while dealing with malicious nodes, all cooperation schemes perform better than Dynamic Source Routing(DSR) protocol in improving packet de- livery ratio(PDR), but this improvement comes at the cost of significant increase in routing control packets overhead and energy consumption of cooperation enforcement schemes is higher than that of DSR. Also they fail in punishing misbehaving nodes and the PDR of malicious nodes is comparable to that of good nodes.
  • ItemOpen Access
    Low drop-out (LDO) voltage regulator without off-chip capacitor
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Agarwal, Gopal; Parikh, Chetan D.
    Designing of Low Drop-Out Voltage Regulators (LDOs) operating without a large off-chip capacitor, having a very good transient response and maintaining the loop stability for full load current range in low supply voltage and low quiescent current environment is a challenging task. The present thesis work proposes a technique to achieve faster loop response during load transients while consuming very less quiescent current. The idea revolves around fast charging and discharging of the large equivalent capacitor at the gate of the pass transistor in response to fast load current transients. The extra circuitry added does not affect the working of main feedback loop in steady state conditions. The idea is inspired from the Nagraj’s idea of achieving high slew rate in operational amplifier which uses an auxiliary circuit to produce large currents in one of the two switching transistors, one for charging and other for discharging the slew rate limiting capacitor in the circuit. A common source amplifier (having i/p v/s o/p characteristic which closely resembles a digital inverter) followed by the large, normally off switching transistor is used here to overcome the slew rate limitation at the gate of pass transistor.