M Tech Dissertations

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

Browse

End date: 2019Has files: No

Search Results

Now showing 1 - 9 of 9
  • Thumbnail Image
    ItemMetadata only
    MIMO reception in Rayleigh and Rician fading with imperfect channel estimation
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2019) Baranwal, Sweety; Vasavada, Yash
    Wireless communication technology has undergone significant improvement over the past decades which has lead to the higher data rates and better bit error rate (BER) performance. There has been increase in the demand for high channel capacity in multipath fading environment which is possible by Multiple Input Multiple output (MIMO) system. MIMO system increases the capacity, makes communication more reliable and reduces the effect of channel fading. Channel State Information (CSI) at the receiver needs to be estimated to improve the performance of detection and estimation of symbols.
  • Thumbnail Image
    ItemMetadata only
    On insider attack in distributed file systems
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2018) Solani, Riddhi; Das, Manik Lal
    Due to heavy use of internet, mobiles, sensors etc. Data is growing rapidly day-by-day. However traditional database systems fail to store such a huge semi structured or unstructured data which raises the need for distributed file systems. Distributed file system is a client server based architecture that can store massive amount of data in any format and provide faster access. However in this kind of systems, security is a major concern as user needs to store their sensitive data away from them. Most of the security solutions available for this kind of systems focus on the detection and prevention of outsider attack but according to recent surveys, insider attack is more frequent than outsider attack in this kind of systems. However there is not much available about the detection of insider attack in the literature. In this work, we've designed an approach to detect the insider attack in distributed file systems. The proposed solution is based on the client-server architecture and data replication property of distributed file systems. As an example of distributed file systems, HDFS is considered. We've designed two algorithms namely process profiling algorithm that run on the datanode and replica and give some output to namenode, attack detection algorithm that run on the namenode which confirms the attack from the information received from the datanode and replica. The proposed solution is simulated and analyzed it in terms of the time complexity.
  • Thumbnail Image
    ItemMetadata only
    Heuristic approach for segment based pairwise sequence alignment in bioinformatics
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2015) Desai, Jeet; Divakaran, Srikrishnan
    0
  • Thumbnail Image
    ItemMetadata only
    Understanding user intent in community question answering
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2014) Shah, Harsh Kaushikbhai; Majumder, Prasenjit
    Yahoo! Answers, Quora like Community Question Answering (CQA) services are mainly created to remove the limitation of Web search engines by helping users to get information from a community. This CQA system has the so many questions in its memory with possible number of answer. And number of times the questions are repeated. So, if the CQA system understand the user intent of question it helps it to recognize similar kind of questions, find relevant answers and hence, recommend potential answers more effectively and effectively. So, thesis approach is to classify the CQA questions, according to user intent, into three categories: objective, subjective, and social. So, to understand the user intent of questions, we first find the text features and metadata features and then through the machine learning algorithms we build a predictive model that classify the questions into above three categories. This one is supervised learning model. We have a very limited number of labeled questions and large number of unlabeled questions. So, to improve the question classification we also use the co-training, a semi supervised learning algorithm, which uses a small set of labeled questions plus a large number of unlabeled questions for classification. Our results shows that the co-training approach that regards text features and metadata features as two views works better than the supervised learning approach that simply applying these two types of features together. This is because co-training, as a semi-supervised learning method, can make use of a large amount of unlabelled questions in addition to the small set of labeled questions.
  • Thumbnail Image
    ItemMetadata only
    Energy efficient protocol for connected dominating set management in wireless sensor network
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2013) Gupta, Arun Kumar; Sunitha, V.; Srivastava, Sanjay
    A wireless Network is a collection of wireless mobiles modes and the access points, where mobile nodes in pure Ad-Hoc mode form a temporary network without requiring any centralized administration wireless communication have one inherent property that any communication is always broadcast so, connection is achieved through transmitting in a range for single hop or multi-hope if they are not in a range of each other. An essential component of effective use of Ad Hoc Wireless networks is proper utilization of available resources and network stability. There has been a recent increase of interest in Ad Hoc networks, partly due to the fact that Ad Hoc networks can be implemented without requiring any support from existing wired backbone or costly hardware setup. Routing in wireless type of scenario is toughest task because of optimal routing requirement. Many approaches have been proposed in last one decade, some of the approaches are based on dominating set, in which either node belongs to dominating set or node have one of it’s neighbor as a dominating set, so we are focusing on construction of adaptive and robust connected dominating set in Ad-Hoc wireless networks, so that dominating set can be used as a backbone of the whole network or a broadcasting set, so smaller the set, efficient the routing and broadcasting. We are proposing a distributed algorithm to create the Connected Dominating Sets (CDS).
  • Thumbnail Image
    ItemMetadata only
    Phase locked loop (PLL) charge pump (CP) design for low power communication applications
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2013) Kapadiya, Anand; Sen, Subhajit
    Phase Locked Loop (PLL) plays a vital role in electronic applications, microprocessors, communication & computers. Recent advancement in wireless technologies & CMOS technologies show many advantages for medical diagnostic & treatment. Now a day, wireless implantable medical devices use RF trans-receiver to exchange data between body & external base station, need low power, low noise Phase Locked Loop (PLL). In this thesis, a Phase Locked Loop (PLL) Synthesizer & charge pump are implemented using BSIM3 180nm CMOS technology which will useful in low power communication applications like Medical Implant Communication Service (MICS) band devices. PLL is control system generating an output signal & its phase is related to an input reference signal phase. PLL Synthesizer can generate range of frequencies from fix input frequency. It consists of Phase Frequency Detector (PFD), Charge Pump (CP), Low Pass Filter (LPF), Voltage Controlled Oscillator (VCO) & Divider. PFD compares the input & output frequency phase & its difference go into CP. CP generate current proportional to phase difference & give it to LPF. LPF generate control voltage & give it to VCO. VCO generate output frequency proportional to control voltage. The output frequency goes into divider in feedback loop & divider output goes to PFD. This whole PLL Synthesizer is implemented using BSIM3 180nm CMOS technology in LTspice-IV tool & simulate in it. I have also implemented Modified CP which will useful for low power PLL Synthesizer. This PLL Synthesizer circuit works at 1.8V power supply, spur of -55dB & consume 3.2mW power. Proposed Modified CP has almost same up-down current & very low leakage current of 1.97pA but in the design random jitter or phase noise has not been considered.
  • Thumbnail Image
    ItemMetadata only
    Service level agreement parameter matching in cloud computing
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2011) Chauhan, Tejas; Chaudhary, Sanjay; Bise, Minal
    Cloud is a large pool of easily usable and accessible virtualized resources (such as hardware, development platforms and/or software services). It provides an on-demand, pay-asyo-ugo computing resources and had become an alternative to traditional IT infrastructure. As more and more consumers delegate their task to cloud providers, Service Level Agreement (SLA) between consumer and provider becomes an important aspect. Due to the dynamic nature of cloud the matching of service level agreement need to be dynamic and continuous monitoring of Quality of Service (QoS) is necessary to enforce SLAs. This complex nature of cloud warrants a sophisticated means of managing SLAs. SLA contains many parameters like cloud’s types of services, resources (physical memory, main memory, processor speed, ethernet speed etc.) and properties (availability, response time, server reboot time etc.). At present, actual Cloud SLAs are typically plain-text documents, and sometimes an informative document published online. Consumer needs to manually match application requirements with each and every cloud provider to identify compatible cloud provider. This work addresses the issue of matching SLA parameters to find best suitable cloud provider. Proposed algorithm identifies the compatible cloud provider by matching parameters of application requirements and cloud SLAs. It gives suggestion to a consumer in terms of number of matched parameters.
  • Thumbnail Image
    ItemMetadata only
    ACIDS: automated co-stimulation based intrusion detection system with a sense of dynamic self
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2005) Kamra, Pooja; Mathuria, Anish M.
    Automated Co-stimulation based Intrusion detection system with a sense of Dynamic Self, or ACIDS, is a distributed architecture for intrusion detection systems. Other than the already used aspects of human immune systems like negative selection, clonal selection, gene expression etc., the novelty of ACIDS is that it incorporates two features of the human system not used previously, namely thymus and vaccination.

    Self is defined as the set of normal connections observed on the network. All the existing systems are modeling the self as a static entity, when it should have been otherwise. Also, human immune system needs two disparate signals before taking some action against the antigen. The first signal is generated at the point of attack and stimulates the immune system for rigorous detection. The second signal is known as co-stimulation, and it stimulates the immune system for taking the action against an antigen. All the existing artificial immune models are also seeking co-stimulation, but it is generated through human intervention. This makes them unusable in real time. Another drawback in the existing systems is that they start from the scratch, i.e. they do not derive knowledge from the existing data of the intrusions.

    ACIDS aims to overcome the above drawbacks of existing models. It includes a module called thymus that dynamically updates the self’s definition of the system. To best of our knowledge, this concept is being used for the first time in intrusion detection systems. In CIDS, hosts are monitored at two levels, network level and operating system level. Whenever an anomaly is detected at the network level, ACIDS monitors the activity of the processes in the host. If anomaly is detected there, system automatically generates the co-stimulation.

  • Thumbnail Image
    ItemMetadata only
    Novel approach for localization in Ad-Hoc sensor networks
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2004) Desai, Vishal; Ranjan, Prabhat
    The ability of a sensor node to move itself or to otherwise influence its location will be critical in sensor networks. Today, the wireless community is putting great effort on the possibility of deploying thousands of tiny sensors all over the place and measuring all kinds of data within. Sensor network is a network of small devices, collaborating with each other to produce a larger sensing task. Most of the current literature on location discovery in wireless and sensor networks assumes the availability of GPS receivers at some nodes or beacon nodes with known position. But as we know having a GPS receiver at sensor nodes may not be feasible due to the limitations of satellite coverage inside the building or due to cost reasons. Further for ad hoc deployment of nodes, it is unreasonable to assume the presence of beacon nodes with prior position information. Hence, the main objective behind this research work is to introduce a localization/positioning method that would be GPS-free and beaconless, and finally we come up with a method called “LRT - Localization using Routing Table” which is also scalable, distributed and able to support the ad hoc deployment of large-scale sensor networks quickly and efficiently.