Engineering Commons^™

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 …

Co-Emulation Of Scan-Chain Based Designs Utilizing Sce-Mi Infrastructure, Bill Jason Pidlaoan Tomas

UNLV Theses, Dissertations, Professional Papers, and Capstones

Simulation times of complex System-on-Chips (SoC) have grown exponentially as designs reach the multi-million ASIC gate range. Verification teams have adopted emulation as a prominent methodology, incorporating high-level testbenches and FPGA/ASIC hardware for system-level testing (SLT). In addition to SLT, emulation enables software teams to incorporate software applications with cycle-accurate hardware early on in the design cycle. The Standard for Co-Emulation Modeling Interface (SCE-MI) developed by the Accelera Initiative, is a widely used communication protocol for emulation which has been accepted by major electronic design automation (EDA) companies.

Scan-chain is a design-for-test (DFT) methodology used for testing digital circuits. To …

Nonlinear Adaptive Diffusion Models For Image Denoising, Ajay Kumar Mandava

UNLV Theses, Dissertations, Professional Papers, and Capstones

Most of digital image applications demand on high image quality. Unfortunately, images often are degraded by noise during the formation, transmission, and recording processes. Hence, image denoising is an essential processing step preceding visual and automated analyses. Image denoising methods can reduce image contrast, create block or ring artifacts in the process of denoising. In this dissertation, we develop high performance non-linear diffusion based image denoising methods, capable to preserve edges and maintain high visual quality. This is attained by different approaches: First, a nonlinear diffusion is presented with robust M-estimators as diffusivity functions. Secondly, the knowledge of textons derived …

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 …

Communication Artifacts And Interaction Evaluation For Requirements Engineering, Miloslava Plachkinova

UNLV Theses, Dissertations, Professional Papers, and Capstones

This paper aims to answer an important question regarding the development of new information systems (IS): "What is the predominant factor for the selection of communication artifacts for requirements engineering (RE)?". Many researchers have focused on the RE and communication as separate disciplines, but little or no research addressed the RE communication issues. These problems are important because they often lead to misunderstanding and misinterpretation of the gathered requirements. We develop expectations about the RE communication process based on prior literature from both disciplines and we test them through several case studies. Our methodology consists of analysis of six case …

Post Processing Of Optically Recognized Text Using First Order Hidden Markov Model, Spandana Malreddy

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we report on our design and implementation of a post processing system for Optically Recognized text. The system is based on first order Hidden Markov Model (HMM). The Maximum Likelihood algorithm is used to train the system with over 150 thousand characters. The system is also tested on a file containing 5688 characters. The percentage of errors detected and corrected is 11.76% with a recall of 10.16% and precision of 100%

Hardware-Software Co-Design, Acceleration And Prototyping Of Control Algorithms On Reconfigurable Platforms, Desta Kumsa Edosa

UNLV Theses, Dissertations, Professional Papers, and Capstones

Differential equations play a significant role in many disciplines of science and engineering. Solving and implementing Ordinary Differential Equations (ODEs) and partial Differential Equations (PDEs) effectively are very essential as most complex dynamic systems are modeled based on these equations. High Performance Computing (HPC) methodologies are required to compute and implement complex and data intensive applications modeled by differential equations at higher speed. There are, however, some challenges and limitations in implementing dynamic system, modeled by non-linear ordinary differential equations, on digital hardware. Modeling an integrator involves data approximation which results in accuracy error if data values are not considered …

Node Filtering And Face Routing For Sensor Network, Umang Amatya

UNLV Theses, Dissertations, Professional Papers, and Capstones

Greedy forward routing and face routing algorithms have been extensively used for sending messages in sensor networks. In this thesis, we consider the problem of filtering redundant nodes in a sensor network as a pre-processing step for face routing. We propose two algorithms for identifying redundant nodes. We test the performance of proposed filtering algorithms on generated networks. The prototype algorithm for testing the proposed algorithms has been implemented in the Java programming language. Experimental investigation shows that the proposed filtering algorithms are effective in removing redundant nodes without compromising the network connectivity.

Cpu Scheduling For Power/Energy Management On Heterogeneous Multicore Processors, Rajesh Patel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Power and energy have become increasingly important concerns in the design and implementation of today's multicore/manycore chips. Many methods have been proposed to reduce a microprocessor's power usage and associated heat dissipation, including scaling a core's operating frequency. However, these techniques do not consider the dynamic performance characteristics of an executing process at runtime, the execution characteristics of the entire task to which this process belongs, the process's priority, the process's cache miss/cache reference ratio, the number of context switches and CPU migrations generated by the process, nor the system load. Also, many of the techniques that employ dynamic frequency …

Non-Blocking Concurrent Operations On Heap, Mahesh Acharya

UNLV Theses, Dissertations, Professional Papers, and Capstones

We present a non-blocking implementation for the concurrent Heap data structure in the asynchronous shared memory system. The system may be a traditional one with a single processor with multiple threads, or it may be the one with multiple processors each possibly with multiple threads. Our implementation supports readMin, deleteMin, and insert operations on the heap. The deleteMin and insert operations are non-blocking operations, whereas the readMin is wait-free. One easy approach of using a heap in multi-threading environment could be by locking the entire heap before performing any operation. This would make the implementation very slow to have any …

Development Of A Simulation Tool For Analysis Of Freeway Crashes Due To Cell Phone Usage, Sourabh Sriom

UNLV Theses, Dissertations, Professional Papers, and Capstones

Research shows that drivers are susceptible to numerous distractions while driving which can be held responsible as the reason of a crash. Usage of cell phones, i.e. talking or texting while driving is considered one of the prominent distractions which causes a crash. This dissertation aims to study the number of crashes occurring on the freeways and their relation with the drivers of these cars using cell phones while they are driving. Since crashes occur relatively less frequently, the study of crashes is done using what is called the "rare event" theory. Java based simulations are done to model a …

Quantification Of Stochastic Uncertainty Propagation For Monte Carlo Depletion Methods In Reactor Analysis, Quentin Thomas Newell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Monte Carlo method provides powerful geometric modeling capabilities for large problem domains in 3-D; therefore, the Monte Carlo method is becoming popular for 3-D fuel depletion analyses to compute quantities of interest in spent nuclear fuel including isotopic compositions. The Monte Carlo approach has not been fully embraced due to unresolved issues concerning the effect of Monte Carlo uncertainties on the predicted results.

Use of the Monte Carlo method to solve the neutron transport equation introduces stochastic uncertainty in the computed fluxes. These fluxes are used to collapse cross sections, estimate power distributions, and deplete the fuel within depletion …

Improved Algorithms For Ear-Clipping Triangulation, Bartosz Kajak

UNLV Theses, Dissertations, Professional Papers, and Capstones

We consider the problem of improving ear-slicing algorithm for triangulating a simple polygon. We propose two variations of ear-slicing technique for generating “good-quality” triangulation. The first approach is based on searching for the best triangle along the boundary. The second approach considers polygon partitioning on a pre-process before applying the ear-slicing. Experimental investigation reveals that both approaches yield better quality triangulation than the standard ear-slicing method.

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 …

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 …

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 …

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 …

Turn Constrained Path Planning Problems, Victor M. Roman

UNLV Theses, Dissertations, Professional Papers, and Capstones

We consider the problem of constructing multiple disjoint paths connecting a source point s to a target point t in a geometric graph. We require that the paths do not have any sharp turn angles. We present a review of turn constrained path planning algorithms and also algorithms for constructing disjoint paths. We then combine these techniques and present an O(nlogn) time algorithm for constructing a pair of edge disjoint turn constrained paths connecting two nodes in a planar geometric graph. We also consider the development of a turn constrained shortest path map in the presence of …

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.

Development Of A Systems Engineering Model For Chemical Separation Process, Lijian Sun

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis is concerned with the efforts to develop a general-purpose systems engineering model software TRPSEMPro1 that can be used to improve productivity in the design process. Different features of TRPSEMPro will be presented in this thesis. First, Systems Engineering technology is presented, followed by the exposition of different numerical optimization technologies and DOE (Design of Experiments) study technologies. Second, the detailed software process, Object-Oriented Analysis and Design (OOA&D) for the TRPSEMPro is presented. All the design data models are expressed by using Unified Modeling Language (UML).

AMUSESimulator is another software package which has been designed and implemented in order …