Computer Engineering Commons^™

Multi-Scale Edge Detection Algorithms And Their Information-Theoretic Analysis In The Context Of Visual Communication, Bo Jiang

Electrical & Computer Engineering Theses & Dissertations

The unrealistic assumption that noise can be modeled as independent, additive and uniform can lead to problems when edge detection methods are applied to low signal-to-noise ratio (SNR) images. The main reason for this is because the filter scale and the threshold for the gradient are difficult to determine at a regional or local scale when the noise estimate is on a global scale. Therefore, in this dissertation, we attempt to solve these problems by using more than one filter to detect the edges and discarding the global thresholding method in the edge discrimination. The proposed multi-scale edge detection algorithms …

Analysis And Optimization Of Dynamic Spectrum Sharing For Cognitive Radio Networks, Manish Wadhwa

Electrical & Computer Engineering Theses & Dissertations

The goal of this dissertation is to present the analysis and optimization of dynamic spectrum sharing for cognitive radio networks (CRNs). Spectrum scarcity is a well known problem at present. In order to deal with this problem, dynamic spectrum sharing (DSS) was proposed. DSS is a technique where cognitive radio networks dynamically and opportunistically share the channels with primary users. The major contribution of this dissertation is in analyzing the problem of dynamic spectrum sharing under different scenarios and developing optimal solutions for these scenarios. In the first scenario, a contention based dynamic spectrum sharing model is considered and its …

Wavelet-Based Enhancement Technique For Visibility Improvement Of Digital Images, Numan ÜNaldı

Electrical & Computer Engineering Theses & Dissertations

Image enhancement techniques for visibility improvement of color digital images based on wavelet transform domain are investigated in this dissertation research.

In this research, a novel, fast and robust wavelet-based dynamic range compression and local contrast enhancement (WDRC) algorithm to improve the visibility of digital images captured under non-uniform lighting conditions has been developed. A wavelet transform is mainly used for dimensionality reduction such that a dynamic range compression with local contrast enhancement algorithm is applied only to the approximation coefficients which are obtained by low-pass filtering and down-sampling the original intensity image. The normalized approximation coefficients are transformed using …

Providing Location Security In Vehicular Ad Hoc Networks, Gongjun Yan

Computer Science Theses & Dissertations

Location is fundamental information in Vehicular Ad-hoc Networks (VANETs). Almost all VANET applications rely on location information. Therefore it is of importance to ensure location information integrity, meaning that location information is original (from the generator), correct (not bogus or fabricated) and unmodified (value not changed). We present validation mechanisms to provide location integrity for VANETs. In the initial mechanism, we assume that all vehicles are equipped with a radar, a GPS receiver, and a transceiver. Since radar has a limited radar range and transceiver has a limited transmission range, we build network cells as a security unit as well …

Determining The Utility Of Technology For Education, Brian Spencer Dillon

Computational Modeling & Simulation Engineering Theses & Dissertations

There is a substantial debate concerning the place of technology in education. This debate has been going on over every technology introduced through at least three millennia although the modern version takes place in journal articles. Technology, in the general sense, is already in the educational arena 1n ways which have become so commonplace that we hardly question them today. More modern technologies, however, meet perpetual resistance in achieving their potential. This paper calls into question the most recent trend in research and suggests a new research paradigm which focuses not only on student achievement, but on a variety of …

Nato Human View Architecture And Human Networks, Holly A. H. Handley, Nancy P. Houston

Engineering Management & Systems Engineering Faculty Publications

The NATO Human View is a system architectural viewpoint that focuses on the human as part of a system. Its purpose is to capture the human requirements and to inform on how the human impacts the system design. The viewpoint contains seven static models that include different aspects of the human element, such as roles, tasks, constraints, training and metrics. It also includes a Human Dynamics component to perform simulations of the human system under design. One of the static models, termed Human Networks, focuses on the human-to-human communication patterns that occur as a result of ad hoc or deliberate …

Challenges For Human, Social, Cultural, And Behavioral Modeling, S. K. Numrich, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

Today's military focus has moved away from the force-on-force battlefield of the past century and into the domain of irregular warfare and its companion security, stability, transition and reconstruction missions. With that change in focus has come a need to examine the operational environment from a wider perspective, one that includes the whole range of human experiences and circumstances. As the set of factors and list of players expands, the need for reliable modeling and simulation increases, if for no other reason than to help the human decision maker make sense of this expanded decision space. However, to do this, …

Security In Ad Hoc Networks And Pervasive Computing, Isaac Z. Wu, X.-Y. Li, M. Song, C.-M. Liu

Electrical & Computer Engineering Faculty Publications

Pervasive computing is an exciting and blooming research field, in which innovative techniques and applications are continuously emerging and aim to provide ambient and personalized services to users with high quality. Ad hoc networks are wireless, self-organizing systems formed by cooperating nodes within communication range of each other that form temporary networks. Their topology is dynamic, decentralized, ever changing and the nodes may move around arbitrarily. The last few years have witnessed a wealth of research ideas on ad hoc networking that are moving rapidly into implemented standards. Technology under development for ad hoc networks and pervasive computing is making …

Using Simulation Systems For Decision Support, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

This chapter describes the use of simulation systems for decision support in support of real operations, which is the most challenging application domain in the discipline of modeling and simulation. To this end, the systems must be integrated as services into the operational infrastructure. To support discovery, selection, and composition of services, they need to be annotated regarding technical, syntactic, semantic, pragmatic, dynamic, and conceptual categories. The systems themselves must be complete and validated. The data must be obtainable, preferably via common protocols shared with the operational infrastructure. Agents and automated forces must produce situation adequate behavior. If these requirements …

M&S Body Of Knowledge: Progress Report And Look Ahead, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

No abstract provided.

Transmitter Optimization In Multiuser Wireless Systems With Quality Of Service Constraints, Danda B. Rawat

Electrical & Computer Engineering Theses & Dissertations

In this dissertation, transmitter adaptation for optimal resource allocation in wireless communication systems are investigated. First, a multiple access channel model is considered where many transmitters communicate with a single receiver. This scenario is a basic component of a. wireless network in which multiple users simultaneously access the resources of a wireless service provider. Adaptive algorithms for transmitter optimization to meet Quality-of-Service (QoS) requirements in a distributed manner are studied. Second, an interference channel model is considered where multiple interfering transmitter-receiver pairs co-exist such that a given transmitter communicates with its intended receiver in the presence of interference from other …