Computer Engineering Commons^™

Simulation, And Overload And Stability Analysis Of Continuous Time Sigma Delta Modulator, Kyung Kang

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ever increasing demand for faster and more powerful digital applications requires high speed, high resolution ADCs. Currently, sigma delta modulators ADCs are extensively used in broadband telecommunication systems because they are an effective solution for high data-rate wireless communication systems that require low power consumption, high speed, high resolution, and large signal bandwidths.

Because mixed-signal integrated circuits such as Continuous Time sigma delta modulators contain both analog and digital circuits, mixed signal circuits are not as simple to model and simulate as all discrete or all analog systems. In this dissertation, the delta transform is used to simulate CT …

Gate Monte Carlo Simulations In A Cloud Computing Environment, Blake Austin Rowedder

UNLV Theses, Dissertations, Professional Papers, and Capstones

The GEANT4-based GATE is a unique and powerful Monte Carlo (MC) platform, which provides a single code library allowing the simulation of specific medical physics applications, e.g. PET, SPECT, CT, radiotherapy, and hadron therapy. However, this rigorous yet flexible platform is used only sparingly in the clinic due to its lengthy calculation time. By accessing the powerful computational resources of a cloud computing environment, GATE's runtime can be significantly reduced to clinically feasible levels without the sizable investment of a local high performance cluster. This study investigated a reliable and efficient execution of GATE MC simulations using a commercial cloud …

An Online Algorithm For The 2-Server Problem On The Line With Improved Competitiveness, Lucas Adam Bang

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis we present a randomized online algorithm for the 2-server problem on the line, named R-LINE (for Randomized Line). This algorithm achieves the lowest competitive ratio of any known randomized algorithm for the 2-server problem on the line.

The competitiveness of R-LINE is less than 1.901. This result provides a significant improvement over the previous known competitiveness of 155/78 (approximately 1.987), by Bartal, Chrobak, and Larmore, which was the first randomized algorithm for the 2-server problem one the line with competitiveness less than 2. Taking inspiration from this algorithm,we improve this result by utilizing ideas from T-theory, game …

Optical Network-On-Chip Architectures And Designs, Lei Zhang

UNLV Theses, Dissertations, Professional Papers, and Capstones

As indicated in the latest version of ITRS roadmap, optical wiring is a viable interconnection technology for future SoC/SiC/SiP designs that can provide broad band data transfer rates unmatchable by the existing metal/low-k dielectric interconnects. In this dissertation study, a set of different optical interconnection architectures are presented for future on-chip optical micro-networks.

Three Optical Network-on-Chip (ONoC) architectures, i.e., Wavelength Routing Optical Network-on-Chip (WRON), Redundant Wavelength Routed Optical Network (RDWRON) and Recursive Wavelength Routed Optical Network (RCWRON) are proposed. They are fully connected networks designed based on passive switching Microring Resonator (MRR) optical switches. Given enough different routing optical wavelengths, …

Self-Stabilizing Leader Election In Dynamic Networks, Hema Piniganti

UNLV Theses, Dissertations, Professional Papers, and Capstones

The leader election problem is one of the fundamental problems in distributed computing. It has applications in almost every domain. In dynamic networks, topology is expected to change frequently. An algorithm A is self-stabilizing if, starting from a completely arbitrary configuration, the network will eventually reach a legitimate configuration.

Note that any self-stabilizing algorithm for the leader election problem is also an algorithm for the dynamic leader election problem, since when the topology of the network changes, we can consider that the algorithm is starting over again from an arbitrary state. There are a number of such algorithms in the …

Self-Stabilizing Group Membership Protocol, Mahesh Subedi

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we consider the problem of partitioning a network into groups of bounded diameter.

Given a network of processes X and a constant D, the group partition problem is the problem of finding a D-partition of X, that is, a partition of X into disjoint connected subgraphs, which we call groups, each of diameter no greater than D. The minimal group partition problem is to find a D-partition {G1, ... Gm} of X such that no two groups can be combined; that is, for any Gi and Gj, where i ≠ j, either Gi U Gj is disconnected …

Dynamic Distributed Programming And Applications To Swap Edge Problem, Feven Z. Andemeskel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Link failure is a common reason for disruption in communication networks. If communication between processes of a weighted distributed network is maintained by a spanning tree T, and if one edge e of T fails, communication can be restored by finding a new spanning tree, T’. If the network is 2-edge connected, T’ can always be constructed by replacing e by a single edge, e’, of the network. We refer to e’ as a swap edge of e.

The best swap edge problem is to find the best choice of e’, that is, that e which causes the new spanning …

A Secure On-Line Credit Card Transaction Method Based On Kerberos Authentication Protocol, Jung Eun Kim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nowadays, electronic payment system is an essential part of modern business. Credit cards or debit cards have been widely used for on-site or remote transactions, greatly reducing the need for inconvenient cash transactions. However, there have been a huge number of incidents of credit card frauds over the Internet due to the security weakness of electronic payment system. A number of solutions have been proposed in the past to prevent this problem, but most of them were inconvenient and did not satisfy the needs of cardholders and merchants at the same time.

In this thesis, we present a new secure …

Hierarchical Routing In Manets Using Simple Clustering, Adam Carnine

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis presents both a review of current MANET routing protocols and a new MANET routing algorithm. The routing protocols reviewed include representative samples from the three primary forms of routing found in MANETS: proactive routing, reactive routing and hybrid routing. Secure algorithms are given special treatment in the review. In addition several protocol enhancements are discussed.

The proposed routing protocol is designed to support networks of a medium size, containing over 200 nodes but less than 3,000 nodes. The design is intentionally simple to allow ease of implementation in comparison with other MANET protocols that provide similar functionality.