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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Shilling attack detection in recommender systems.

Bhebe, Wilander. January 2015 (has links)
M. Tech. Information Networks / The growth of the internet has made it easy for people to exchange information resulting in the abundance of information commonly referred to as information overload. It causes retailers to fail to make adequate sales since the customers are swamped with a lot of options and choices. To lessen this problem retailers have begun to find it useful to make use of algorithmic approaches to determine which content to show consumers. These algorithmic approaches are known as recommender systems. Collaborative Filtering recommender systems suggest items to users based on other users reported prior experience with those items. These systems are, however, vulnerable to shilling attacks since they are highly dependent on outside sources of information. Shilling is a process in which syndicating users can connive to promote or demote a certain item, where malicious users benefit from introducing biased ratings. It is, however, critical that shilling detection systems are implemented to detect, warn and shut down shilling attacks within minutes. Modern patented shilling detection systems employ: (a) classification methods, (b) statistical methods, and (c) rules and threshold values defined by shilling detection analysts, using their knowledge of valid shilling cases and the false alarm rate as guidance. The goal of this dissertation is to determine a context for, and assess the performance of Meta-Learning techniques that can be integrated in the shilling detection process.
32

Designing authenication scheme for wireless sensor networks

Wang, Ke, 黃岢 January 2009 (has links)
published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy
33

Object detection in low resolution video sequences

Unknown Date (has links)
With augmenting security concerns and decreasing costs of surveillance and computing equipment, research on automated systems for object detection has been increasing, but the majority of the studies focus their attention on sequences where high resolution objects are present. The main objective of this work is the detection and extraction of information of low resolution objects (e.g. objects that are so far away from the camera that they occupy only tens of pixels) in order to provide a base for higher level information operations such as classification and behavioral analysis. The system proposed is composed of four stages (preprocessing, background modeling, information extraction, and post processing) and uses context based region of importance selection, histogram equalization, background subtraction and morphological filtering techniques. The result is a system capable of detecting and tracking low resolution objects in a controlled background scene which can be a base for systems with higher complexity. / by Diego F. Pava. / Thesis (M.S.C.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.
34

Smart campus

Unknown Date (has links)
The Smart Campus project envisions a university campus where technology assists faculty, staff, students and visitors to improve and more efficiently accomplish their daily activities. The objective of this project is to develop a smart phone application that assists users in finding a certain location on campus, locating their friends and professors, interacting with any student or professors of the campus, get the count of users at certain locations and remain updated about all the events and campus news. Through this project, an idea of ‘Futuristic Social Network’ in a Campus is modeled and developed on Android platform. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
35

A utility-based routing scheme in multi-hop wireless networks

Unknown Date (has links)
Multi-hop wireless networks are infrastructure-less networks consisting of mobile or stationary wireless devices, which include multi-hop wireless mesh networks and multi-hop wireless sensor networks. These networks are characterized by limited bandwidth and energy resources, unreliable communication, and a lack of central control. These characteristics lead to the research challenges of multi-hop wireless networks. Building up routing schemes with good balance among the routing QoS (such as reliability, cost, and delay) is a paramount concern to achieve high performance wireless networks. These QoS metrics are internally correlated. Most existing works did not fully utilize this correlation. We design a metric to balance the trade-off between reliability and cost, and build up a framework of utility-based routing model in multi-hop wireless networks. This dissertation focuses on the variations with applications of utility-based routing models, designing new concepts, and developing new algorithms for them. A review of existing routing algorithms and the basic utility-based routing model for multi-hop wireless networks has been provided at the beginning. An efficient algorithm, called MaxUtility, has been proposed for the basic utility-based routing model. MaxUtility is an optimal algorithm that can find the best routing path with the maximum expected utility. / Various utility-based routing models are extended to further enhance the routing reliability while reducing the routing overhead. Besides computing the optimal path for a given benefit value and a given source-destination pair, the utility-based routing can be further extended to compute all optimal paths for all possible benefit values and/or all source-destination pairs. Our utility-based routing can also adapt to different applications and various environments. In the self-organized environment, where network users are selfish, we design a truthful routing, where selfish users have to tell the truth in order to maximize their utilities. We apply our utility-based routing scheme to the data-gathering wireless sensor networks, where a routing scheme is required to transmit data sensed by multiple sensor nodes to a common sink node. / by Mingming Lu. / Vita. / University Library's copy lacks signatures of Supervisory Committee. / Thesis (Ph.D.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, FL : 2008 Mode of access: World Wide Web.
36

Content identification using video tomography

Unknown Date (has links)
Video identification or copy detection is a challenging problem and is becoming increasingly important with the popularity of online video services. The problem addressed in this thesis is the identification of a given video clip in a given set of videos. For a given query video, the system returns all the instance of the video in the data set. This identification system uses video signatures based on video tomography. A robust and low complexity video signature is designed and implemented. The nature of the signature makes it independent to the most commonly video transformations. The signatures are generated for video shots and not individual frames, resulting in a compact signature of 64 bytes per video shot. The signatures are matched using simple Euclidean distance metric. The results show that videos can be identified with 100% recall and over 93% precision. The experiments included several transformations on videos. / by Gustavo A. Leon. / Thesis (M.S.C.S.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.
37

The inexact Newton-like method for inverse eigenvalue problem and a DCT based watermarking scheme for copyright protection of images.

January 2002 (has links)
by Hau-Leung Chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 41-42). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.5 / Chapter 1.1 --- Paper I --- p.5 / Chapter 1.2 --- Paper II --- p.6 / Chapter 2 --- The Inexact Newton-Like Method for Inverse Eigen- value Problem --- p.8 / Chapter 2.1 --- Introduction --- p.8 / Chapter 2.2 --- The Newton-Like Method --- p.9 / Chapter 2.3 --- The Inexact Newton-Like Method --- p.11 / Chapter 2.4 --- Convergence Analysis --- p.14 / Chapter 2.5 --- Numerical Experiments --- p.22 / Chapter 3 --- A DCT Based Watermarking Scheme for Copyright Protection of Images --- p.26 / Chapter 3.1 --- Introduction --- p.26 / Chapter 3.2 --- Preliminary --- p.28 / Chapter 3.2.1 --- Gray-level image --- p.28 / Chapter 3.2.2 --- Color image --- p.29 / Chapter 3.2.3 --- The Discrete Cosine transform --- p.30 / Chapter 3.3 --- Watermarking Approaches --- p.31 / Chapter 3.3.1 --- Insertion procedures --- p.31 / Chapter 3.3.2 --- Retrieval procedures --- p.33 / Chapter 3.4 --- Experimental results --- p.34 / Chapter 3.5 --- Other Applications --- p.38 / Chapter 3.5.1 --- Data Hiding --- p.38 / Chapter 3.5.2 --- Authentication --- p.39 / Chapter 3.5.3 --- Fingerprinting --- p.39 / Chapter 3.5.4 --- Copy Control --- p.39 / Chapter 3.6 --- Conclusion --- p.40 / Bibliography --- p.41
38

A Flexible FPGA-Assisted Framework for Remote Attestation of Internet Connected Embedded Devices

Patten, Jared Russell 01 March 2018 (has links)
Embedded devices permeate our every day lives. They exist in our vehicles, traffic lights, medical equipment, and infrastructure controls. In many cases, improper functionality of these devices can present a physical danger to their users, data or financial loss, etc. Improper functionality can be a result of software or hardware bugs, but now more than ever, is often the result of malicious compromise and tampering, or as it is known colloquially "hacking". We are beginning to witness a proliferation of cyber-crime, and as more devices are built with internet connectivity (in the so called "Internet of Things"), security should be of the utmost concern. Embedded devices have begun to seamlessly merge with our daily existence. Therefore the need for security grows as it more directly affects the safety of our data, property, and even physical health. This thesis presents an FPGA-assisted framework for remote attestation, a security service that allows a remote device to prove to a verifying entity that it can be trusted. In other words, it presents a protocol by which a device (be it an insulin pump, vehicle, etc.) can prove to a user (or other entity) that it can be trusted - i.e. that it has not been "hacked". This is accomplished through executable code integrity verification and run-time monitoring. In essence, the protocol verifies that a device is running authorized and untampered software and makes it known to a verifier in a trusted fashion. We implement the protocol on a physical device to demonstrate its feasibility and to examine its performance impact.
39

Developing a Risk Management System for Information Systems Security Incidents

Farahmand, Fariborz 22 November 2004 (has links)
The Internet and information systems have enabled businesses to reduce costs, attain greater market reach, and develop closer business partnerships along with improved customer relationships. However, using the Internet has led to new risks and concerns. This research provides a management perspective on the issues confronting CIOs and IT managers. It outlines the current state of the art of information security, the important issues confronting managers, security enforcement measure/techniques, and potential threats and attacks. It develops a model for classification of threats and control measures. It also develops a scheme for probabilistic evaluation of the impact of security threats with some illustrative examples. It involves validation of information assets and probabilities of success of attacks on those assets in organizations and evaluates the expected damages of these attacks. The research outlines some suggested control measures and presents some cost models for quantifying damages from these attacks and compares the tangible and intangible costs of these attacks. This research also develops a risk management system for information systems security incidents in five stages: 1- Resource and application value analysis, 2- Vulnerability and risk analysis, 3- Computation of losses due to threats and benefits of control measures, 4- Selection of control measures, and 5- Implementation of alternatives. The outcome of this research should help decision makers to select the appropriate control measure(s) to minimize damage or loss due to security incidents. Finally, some recommendations for future work are provided to improve the management of security in organizations.
40

Actual and Perceived Information Systems Security

Oscarson, Per January 2007 (has links)
As the Internet becomes the major information infrastructure in most sectors, the importance of Information Systems (IS) security steadily increases. While reaching a certain level of actual IS security is vital for most businesses, this level must also be perceived as acceptable by stakeholders. Businesses have to maintain a certain level of security and be able to assess the level of other actors’ security. IS security is abstract and complex, however, and difficult to estimate and measure. This thesis uses epistemic and ontological frameworks to study the conceptual nature of IS security and separate the concepts of actual and perceived IS security. A well-known event is used to illustrate the conceptual discussion: the Sasser worm that was spread around the world in 2004. This study also includes a smaller case study from the City of Stockholm, where about 4,000 computers were infected by Sasser. The outcome of the study is that actual IS security should be treated as a dynamic condition that is influenced by three different objects: information assets, threat objects and security mechanisms. Incidents are processes that are ruled by the conditions of these three objects and affect the states of confidentiality, integrity and availability of information assets. The concepts of threat, risk and trust remain at epistemic level, i.e. perceptions. Perceptions of IS security can differ depending on their social establishment and are classified as subjective judgements, inter-subjective judgements or institutional facts. While actual IS security conditions can influence actors’ perceptions of IS security, perceived IS security can also influence actual IS security.

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