Computer Sciences Commons^™

Simulation Of Discrete Electromagnetic Propagation Model For Atmospheric Effects On Mobile Communication, Şaban Seli̇m Şeker, Fulya Kunter

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless communication has become an important part of our lives, and atmospheric effects are one of the ultimate factors affecting quality of communication and satellite systems. In this study the attenuation in mobile communication due to atmospheric events like snow and rain is simulated using the discrete propagation model. In this work, spherical raindrop and oblate spheroid raindrop modeling are used. To check the validity of simulations, the commonly used and accepted ITU-R rain model is used. Oblate spheroid raindrop modeling produces results that are more compatible with ITU-R results, especially at frequencies higher than 50 GHz. At lower frequencies, …

Applications Of Agent Based Approaches In Business: A Three Essay Dissertation, Shankar Prawesh

USF Tampa Graduate Theses and Dissertations

The goal of this dissertation is to investigate the enabling role that agent based simulation plays in business and policy. The aforementioned issue has been addressed in this dissertation through three distinct, but related essays. The first essay is a literature review of different research applications of agent based simulation in various business disciplines, such as finance, economics, information systems, management, marketing and accounting. Various agent based simulation tools to develop computational models are discussed. The second essay uses an agent-based simulation approach to study important properties of the widely used most popular news recommender systems (NRS). This essay highlights …

Secure Key Deployment And Exchange Protocol For Manet Information Management, Brian Cusack, Alastair Nisbet

Australian Digital Forensics Conference

Secure Key Deployment and Exchange Protocol (SKYE) is an innovative encryption Key Management Scheme (KMS) based on a combination of features from recent protocols combined with new features for Mobile Ad Hoc Networks (MANETs). The design focuses on a truly ad hoc networking environment where geographical size of the network, numbers of network members and mobility of the members is all unknown before deployment. This paper describes the process of development of the protocol and the application to system design to assure information security and potential evidential retention for forensic purposes. Threshold encryption key management is utilized and simulation results …

A Computational Analysis Of Bundle Trading Markets Design For Distributed Resource Allocation, Zhiling Guo, Gary J. Koehler, Andrew B. Whinston

Research Collection School Of Computing and Information Systems

Online auction markets play increasingly important roles for resource allocations in distributed systems. This paper builds upon a market-based framework presented by Guo et al. (Guo, Z., G. J. Koehler, A. B. Whinston. 2007. A market-based optimization algorithm for distributed systems. Management Sci. 53(8) 1345–1458), where a distributed system optimization problem is solved by self-interested agents iteratively trading bundled resources in a double auction market run by a dealer. We extend this approach to a dynamic, asynchronous Internet market environment and investigate how various market design factors including dealer inventory policies, market communication patterns, and agent learning strategies affect the …

Simulation, Development And Deployment Of Mobile Wireless Sensor Networks For Migratory Bird Tracking, William P. Bennett Jr.

School of Computing: Dissertations, Theses, and Student Research

This thesis presents CraneTracker, a multi-modal sensing and communication system for monitoring migratory species at the continental level. By exploiting the robust and extensive cellular infrastructure across the continent, traditional mobile wireless sensor networks can be extended to enable reliable, low-cost monitoring of migratory species. The developed multi-tier architecture yields ecologists with unconventional behavior information not furnished by alternative tracking systems at such a large scale and for a low-cost. The simulation, development and implementation of the CraneTracker software system is presented. The system is shown effective through multiple proxy deployments on wildlife and has been operational for 10 months …

Fast And Efficient Classification, Tracking, And Simulation In Wireless Sensor Networks, Hao Jiang

All Dissertations

Wireless sensor networks are composed of large numbers of resource-lean sensors that collect low-level inputs from the physical world. The applications present challenges for programmers. On the one hand, lightweight algorithms are required given the limited capacity of the constituent devices. On the other, the algorithms must be scalable to accommodate large networks. In this thesis, we focus on the design and implementation of fast and lean (yet scalable) algorithms for classification, simulation, and target tracking in the context of wireless sensor networks. We briefly consider each of these challenges in turn.
The first challenge is to achieve high precision …

Peer-To-Peer Simulation Of Massive Virtual Environments, James Dean Mathias

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Massively multiplayer games make up a large and growing segment of the computer game industry. One of the best known examples of these games is World of Warcraft, developed and published by Activision Blizzard. World of Warcraft boasts a subscriber base of over eleven million active subscribers, earning an estimated $1 billion dollars in 2010.

Some of the core issues for companies that publish these games are the cost of the computers, Internet bandwidth usage, and supporting technical staff. These costs easily reach hundreds of thousands of dollars each month, and in the case of World of Warcraft, millions of …

A Radio Link Quality Model And Simulation Framework For Improving The Design Of Embedded Wireless Systems, Sally Wahba

All Dissertations

Despite the increasing application of embedded wireless systems, developers face numerous challenges during the design phase of the application life cycle. One of the critical challenges is ensuring performance reliability with respect to radio link quality. Specifically, embedded links experience exaggerated link quality variation, which results in undesirable wireless performance characteristics. Unfortunately, the resulting post-deployment behaviors often necessitate network redeployment.
Another challenge is recovering from faults that commonly occur in embedded wireless systems, including node failure and state corruption. Self-stabilizing algorithms can provide recovery in the presence of such faults. These algorithms guarantee the eventual satisfaction of a given state …

Performance Evaluation Of Optimal Rate Allocation Models For Wireless Networks, Ryan Michael Padilla

Theses and Dissertations

Convex programming is used in wireless networks to optimize the sending or receiving rates of links or flows in a network. This kind of optimization problem is formulated into a rate allocation problem, where each node in the network will distributively solve the convex problem and all links or flows will converge to their optimal rate. The objective function and constraints of these problems are represented in a simplified model of contention, interference, and sending or receiving rates. The Partial Interference model is an optimal rate allocation model for use in wireless mesh networks that has been shown to be …

Application Monitoring And Checkpointing In Hpc: Looking Towards Exascale Systems, William M. Jones, John T. Daly, Nathan A. Debardeleben

Computing Sciences

As computational cluster computers rapidly grow in both size and complexity, system reliability and, in particular, application resilience have become increasingly important factors to consider in maintaining efficiency and providing improved compute performance over predecessor systems. One commonly used mechanism for providing application fault tolerance in parallel systems is the use of checkpointing.

We demonstrate the impact of sub-optimal checkpoint intervals on application efficiency via simulation with real workload data. We find that application efficiency is relatively insensitive to error in estimation of an application's mean time to interrupt (AMTTI), a parameter central to calculating the optimal checkpoint interval. This …

Using Agent-Based Models To Understand Multi-Operator Supervisory Control, Yisong Guo

Theses and Dissertations

As technology advances, many practical applications require human-controlled robots. For such applications, it is useful to determine the optimal number of robots an operator should control to maximize human efficiency given different situations. One way to achieve this is through computer simulations of team performance. In order to factor in various parameters that may affect team performance, an agent-based model will be used. Agent-based modeling is a computational method that enables a researcher to create, analyze, and experiment with models composed of agents that interact within an environment [12]. We construct an agent-based model of humans interacting with robots, and …

Parsing The Relationship Between Baserunning And Batting Abilities Within Lineups, Ben S. Baumer, James Piette, Brad Null

Statistical and Data Sciences: Faculty Publications

A baseball team's offensive prowess is a function of two types of abilities: batting and baserunning. While each has been studied extensively in isolation, the effects of their interaction is not well understood. We model offensive output as a scalar function f of an individual player's batting and baserunning profile z. Each of these profiles is in turn estimated from Retrosheet data using heirarchical Bayesian models. We then use the SimulOutCome simulation engine as a method to generate values of f(z) over a fine grid of points. Finally, for each of several methods of taking the extra base, we graphically …

Simulation Of Mobile Treatment Monitoring System, Emre Ermisoglu

Theses and Dissertations

Noncompliance is the main reason for treatment failure. Approximately 50 to 75% of patients misuse their medication due to forgetfulness and busy schedule. Instead of heavily depending on patient's memory for following medication deadlines, we propose a new automated medication helper called "Mobile Treatment Monitoring System" to help patients take their medication on time. Among other technologies that help patients to follow up their medication such as Pill Organizers, Medication Reminders, and Pill Dispensers, using remote treatment monitoring system appears to be a promising technology because system creates a direct link between doctor and patient so doctor will be notified …

Modeling And Simulation Of Hpc System Through Job Scheduling Analysis, William Bradley Hurst

Theses and Dissertations

The sophistication of the devices through which a man shapes his world are the tool-marks of his development upon history. One device currently shaping the lives of man is the High Performance Computer (HPC) system. HPC systems have been described as ``a game changing technology (King and BusinessWeek, 2010).'' The reason for HPC systems to be declared ``a game changing technology (King and BusinessWeek, 2010)'' comes from the fact that it is cheaper for a manufacturer to conduct thousands of tests in virtual space, than it is to try multiple experimental designs in the physical world. Through capabilities of HPC …

A Framework For Generating Data To Simulate Application Scoring, Kenneth Kennedy, Sarah Jane Delany, Brian Mac Namee

Conference papers

In this paper we propose a framework to generate artificial data that can be used to simulate credit risk scenarios. Artificial data is useful in the credit scoring domain for two reasons. Firstly, the use of artificial data allows for the introduction and control of variability that can realistically be expected to occur, but has yet to materialise in practice. The ability to control parameters allows for a thorough exploration of the performance of classification models under different conditions. Secondly, due to non-disclosure agreements and commercial sensitivities, obtaining real credit scoring data is a problematic and time consuming task. By …

Simcol: A Simulation Tool For Computer-Supported Collaborative Learning, Nobel Khandaker, Leen-Kiat Soh

School of Computing: Faculty Publications

Researchers designing the multiagent tools and techniques for computer-supported collaborative learning (CSCL) environments are often faced with high cost, time, and effort required to investigate the effectiveness of their tools and techniques in large scale and longitudinal studies in a real-world environment containing human users. Here, we propose SimCoL, a multiagent environment that simulates collaborative learning among students and agents providing support to the teacher and the students. Our goal with SimCoL is to provide a comprehensive test bed for multiagent researchers to investigate 1) theoretical multiagent research issues, e.g., coalition formation, multiagent learning, and communication, where humans are involved …

Multiagent Coalition Formation In Uncertain Environments With Type-Changing Influences And Its Application Towards Forming Human Coalitions, Nobel A. Khandaker

School of Computing: Dissertations, Theses, and Student Research

We aim to solve the problem forming multiagent coalitions in uncertain environments where the coalition members’ capability of solving tasks change due to their learning. The MCFP-Mproblem for the agents refers to forming or joining coalitions on behalf of a set of human users so that those human users can solve tasks and improve their types (expertise) to improve their performances over time. MCFP-A problem for a set of agents refers to their forming or joining coalitions so that they are able to solve a set of assigned tasks while optimize their performance over time. We propose the Integrated Human …

The Impact Of The User Interface On Simulation Usability And Solution Quality, Bruce Ray Montgomery

CCAC Theses and Dissertations

This research outlines a study that was performed to determine the effects of user interface design variations on the usability and solution quality of complex, multivariate discrete-event simulations. Specifically, this study examined four key research questions: what are the user interface considerations for a given simulation model, what are the current best practices in user interface design for simulations, how is usability best evaluated for simulation interfaces, and specifically what are the measured effects of varying levels of usability of interface elements on simulation operations such as data entry and solution analysis. The overall goal of the study was to …

The Design Of Xml-Based Model And Experiment Description Languages For Network Simulation, Andy Hallagan

Honors Theses

The Simulation Automation Framework for Experiments (SAFE) is a project created to raise the level of abstraction in network simulation tools and thereby address issues that undermine credibility. SAFE incorporates best practices in network simulationto automate the experimental process and to guide users in the development of sound scientific studies using the popular ns-3 network simulator. My contributions to the SAFE project: the design of two XML-based languages called NEDL (ns-3 Experiment Description Language) and NSTL (ns-3 Script Templating Language), which facilitate the description of experiments and network simulationmodels, respectively. The languages provide a foundation for the construction of better …

Computational Modeling Of Biological Neural Networks On Gpus: Strategies And Performance, Byron Galbraith

Master's Theses (2009 -)

Simulating biological neural networks is an important task for computational neuroscientists attempting to model and analyze brain activity and function. As these networks become larger and more complex, the computational power required grows significantly, often requiring the use of supercomputers or compute clusters. An emerging low-cost, highly accessible alternative to many of these resources is the Graphics Processing Unit (GPU) - specialized massively-parallel graphics hardware that has seen increasing use as a general purpose computational accelerator thanks largely due to NVIDIA's CUDA programming interface. We evaluated the relative benefits and limitations of GPU-based tools for large-scale neural network simulation and …

Model Based Analysis Of Some High Speed Network Issues, Suman Kumar

LSU Doctoral Dissertations

The study of complex problems in science and engineering today typically involves large scale data, huge number of large-scale scientific breakthroughs critically depends on large multi-disciplinary and geographically-dispersed research teams, where the high speed network becomes the integral part. To serve the ongoing bandwidth requirement and scalability of these networks, there has been a continuous evolution of different TCPs for high speed networks. Testing these protocols on a real network would be expensive, time consuming and more over not easily available to the researchers worldwide. Network simulation is well accepted and widely used method for performance evaluation, it is well …

Dynamic Multivariate Simplex Splines For Volume Representation And Modeling, Yunhao Tan

Wayne State University Dissertations

Volume representation and modeling of heterogeneous objects acquired from real world are very challenging research tasks and playing fundamental roles in many potential applications, e.g., volume reconstruction, volume simulation and volume registration. In order to accurately and efficiently represent and model the real-world objects, this dissertation proposes an integrated computational framework based on dynamic multivariate simplex splines (DMSS) that can greatly improve the accuracy and efficacy of modeling and simulation of heterogenous objects. The framework can not only reconstruct with high accuracy geometric, material, and other quantities associated with heterogeneous real-world models, but also simulate the complicated dynamics precisely by …

Behaviors Of Real-Time Schedulers Under Resource Modification And A Steady Scheme With Bounded Utilization, Refi̇k Samet, Orhan Fi̇kret Duman

Turkish Journal of Electrical Engineering and Computer Sciences

In this article we present an analysis for task models having random resource needs and different arrival patterns. In hard real-time environments like avionic systems or nuclear reactors, the inputs to the system are obtained from real world by using sensors. And it is highly possible for a task to have different resource needs for each period according to these changing conditions of real world. We made an analysis of schedulers for task models having random resources in each period. Since feasibility tests for usual task models are just limited to some specific schedulers and arrival patterns, we made our …

Dynamic Load Balancing For I/O-Intensive Applications On Clusters, Xiao Qin, Hong Jiang, Adam Manzanares, Xiaojun Ruan, Shu Yin

School of Computing: Faculty Publications

Load balancing for clusters has been investigated extensively, mainly focusing on the effective usage of global CPU and memory resources. However, previous CPU- or memory-centric load balancing schemes suffer significant performance drop under I/O-intensive workloads due to the imbalance of I/O load. To solve this problem, we propose two simple yet effective I/O-aware load-balancing schemes for two types of clusters: (1) homogeneous clusters where nodes are identical and (2) heterogeneous clusters, which are comprised of a variety of nodes with different performance characteristics in computing power, memory capacity, and disk speed. In addition to assigning I/O-intensive sequential and parallel jobs …

Visualizing The Simulation Of 3-D Underwater Sensor Networks, Matthew T. Tran

Honors Scholar Theses

The majority of sensor network research deals with land-based networks, which are essentially two-dimensional, and thus the majority of simulation and animation tools also only handle such networks. Underwater sensor networks on the other hand, are essentially 3D networks because the depth at which a sensor node is located needs to be considered as well. Due to that additional dimension, specialized tools need to be used when conducting simulations for experimentation.

The School of Engineering’s Underwater Sensor Network (UWSN) lab is conducting research on underwater sensor networks and requires simulation tools for 3D networks. The lab has extended NS-2, a …

A Method For Introducing Artificial Perception (Ap) To Improve Human Behavior Representation (Hbr) Using Agents In Synthetic Environments, Randall Bartholomew Garrett

Computational Modeling & Simulation Engineering Theses & Dissertations

While psychology has shown that perception is very important for the human decision process, agent perception has not been covered in sufficient detail within the agent directed simulation field. To contribute to such a solution, an open challenge lies in capturing the knowledge of human sciences, such as psychology, and making this knowledge usable for engineers. This dissertation addresses perception by describing an experimental method where agent perception simulates human perception. In particular, it presents engineering methods based on accepted psychological approaches resulting in a proof of concept. To prove the feasibility, an Artificial Perception (AP) meta-model is presented using …

The Impact Of Communication Medium On Team Performance Patterns, Pilar Pazos, Mario G. Beruvides

Engineering Management & Systems Engineering Faculty Publications

The increased impact of globalization and rapidly changing technologies are some of the biggest challenges facing 21st century organizations. Remote teams supported through computer-based systems have been identified as a key lever to help organizations adapt to this turbulent environment. This study sheds some light on how teams perform and adapt by evaluating performance and synergy over time for teams in two different settings: computer supported and face-to-face. Participants in the study were randomly assigned either to a computer-supported or a face-to face group. Each group met over three sessions to perform a series of tasks that were evaluated using …

A Software Framework For The Design, Testing And Deployment Of Control Systems For Autonomous Robotics, Duane Stanley Bolick Jr.

Browse all Theses and Dissertations

Simulation and control of robotic agents are common enough tasks among computer science and engineering researchers that there exists a large variety of software applications, toolkits, and programming frameworks designed to facilitate such research. The intent of this project is to provide an autonomous robotics simulation and control framework with sufficiently useful tools and reference implementations so as to be immediately useful to basic users, as well as easily understood and extended by software developers and robotics researchers.

As such, this document describes the implementation of a general networking toolkit, an autonomous robotics extension framework, and an autonomous robotics simulator …

Protecting Critical Infrastructure With Games Technology, Adrian Boeing, Martin Masek, Bill Bailey

Australian Information Warfare and Security Conference

It is widely recognised that there is a considerable gap in the protection of the national infrastructure. Trying to identify what is in fact ‘critical’ is proving to be very difficult as threats constantly evolve. An interactive prototyping tool is useful in playing out scenarios and simulating the effect of change, however existing simulators in the critical infrastructure area are typically limited in the visual representation and interactivity. To remedy this we propose the use of games technology. Through its use, critical infrastructure scenarios can be rapidly constructed, tested, and refined. In this paper, we highlight the features of games …

An Open Framework For Highly Concurrent Real-Time Hardware-In-The-Loop Simulation, Ryan C. Underwood, Bruce M. Mcmillin, Mariesa Crow

Computer Science Faculty Research & Creative Works

Hardware-in-the-loop (HIL) real-time simulation is becoming a significant tool in prototyping complex, highly available systems. The HIL approach permits testing of hardware prototypes of components that would be extremely costly or difficult to test in the deployed environment. In power system simulation, key issues are the ability to wrap the systems of equations (such as Partial Differential Equations) describing the deployed environment into real-time software models, provide low synchronization overhead between the hardware and software, and reduce reliance on proprietary platforms. This paper introduces an open source HIL simulation framework that can be ported to any standard Unix-like system on …