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Control And Diagnosis Of Real-Time Systems Under Finite-Precision Measurement Of Time, Songyan Xu 2010 Iowa State University

Control And Diagnosis Of Real-Time Systems Under Finite-Precision Measurement Of Time, Songyan Xu

Graduate Theses and Dissertations

A discrete event system (DES) is an event-driven system that evolves according to abrupt occurrences of discrete changes (events). The domain of such systems encompasses aspects of many man-made systems such as manufacturing systems, telephone networks, communication protocols, traffic systems, embedded software, asynchronous hardware, robotics, etc.

Supervisory control theory for DESs studies the existence and synthesis of the supervisory controllers, namely, supervisors that restrict the system behaviors by dynamically disabling certain controllable events so that the controlled close-loop system could behave as desired. Extensive work on supervisory control of untimed DESs exists and the extension to the timed setting has ...


Methods For Integrated Biochemical Pathway Analysis, John Louis Van Hemert 2010 Iowa State University

Methods For Integrated Biochemical Pathway Analysis, John Louis Van Hemert

Graduate Theses and Dissertations

The common goal for biological research is to develop models for the biological processes we seek to understand. Such models, in the form of biochemical pathway networks which describe the physical interactions between a living cell's genes, transcripts, proteins, and metabolites ("Omics"), accumulate in different repositories for several model organisms as well as non-model organisms. This thesis presents a set of integrated statistical bioinformatics tools that address key problems in integrating large-scale Omics datasets with pathway network models. A hardware accelerated non-parametric Omics mining method (Monte Carlo on the GPU) allows faster screening of custom test statistics and functions ...


Performance Evaluation And Finite Element Verification Of An Ultra-High Performance Concrete Pi-Girder Bridge, Owen Bryant Berg 2010 Iowa State University

Performance Evaluation And Finite Element Verification Of An Ultra-High Performance Concrete Pi-Girder Bridge, Owen Bryant Berg

Graduate Theses and Dissertations

The Jakway Park Bridge in Buchanan County, Iowa is the first bridge constructed with a new prestesssed girder system composed of precast Ultra-High Performance Concrete (UHPC). These girders employ an integral deck to facilitate construction and are referred to as pi-girders for the resemblance of their cross-section to the Greek letter, "π". The evolution of the girder geometry, simplifying assumptions, and finite element analysis techniques used in design of the bridge are examined, and the results of laboratory and live load testing are presented to quantify behavior. The effectiveness of the finite element analysis, structural performance of the bridge, including ...


Scenario Reduction Heuristics For A Rolling Stochastic Programming Simulation Of Bulk Energy Flows With Uncertain Fuel Costs, Yan Wang 2010 Iowa State University

Scenario Reduction Heuristics For A Rolling Stochastic Programming Simulation Of Bulk Energy Flows With Uncertain Fuel Costs, Yan Wang

Graduate Theses and Dissertations

Stochastic programming is employed regularly to solve energy planning problems with uncertainties in costs, demands and other parameters. We formulated a stochastic program to quantify the impact of uncertain fuel costs in an aggregated U.S. bulk energy transportation network model. A rolling two-stage approach with discrete scenarios is implemented to mimic the decision process as realizations of the uncertain elements become known and forecasts of their values in future periods are updated. Compared to the expected value solution from the deterministic model, the recourse solution found from the stochastic model has higher total cost, lower natural gas consumption and ...


Text Mining For Systems Biology And Metnet, Lifeng Zhang 2010 Iowa State University

Text Mining For Systems Biology And Metnet, Lifeng Zhang

Graduate Theses and Dissertations

The rapidly expanding volume of biological and biomedical literature motivates demand for more friendly access. Better automated mining of this literature can help find useful and desired citations and can extract new knowledge from the massive biological "literaturome." The research objectives presented here, when met, will provide comprehensive text mining utilities within the MetNet (Metabolic Network Exchange) (Wurtele et al., 2007), platform to help biologists visualize, explore, and analyze the biological literaturome. The overarching research question to be addressed is how to automatically extract biomolecular interactions from numerous biomedical texts. Here are the specific aims of this work.

1. Research ...


A Fast Ascent Trajectory Optimization Method For Hypersonic Air-Breathing Vehicles, Oscar Jaime Murillo 2010 Iowa State University

A Fast Ascent Trajectory Optimization Method For Hypersonic Air-Breathing Vehicles, Oscar Jaime Murillo

Graduate Theses and Dissertations

The objective of this dissertation is to investigate a fast and reliable method to generate three-dimensional optimal ascent trajectories for hypersonic air-breathing vehicles. The problem is notoriously difficult because of the strong nonlinear coupling amongst aerodynamics, propulsion, vehicle attitude and trajectory state. As such an algorithm matures, the ultimate goal is to realize optimal closed-loop ascent guidance for hypersonic air-breathing vehicles. The problem is formulated as a fuel-optimal control problem. The corresponding necessary conditions are given. It is shown how the original problem of search for the optimal control commands can be reduced to a univariate root-finding problem at each ...


Soy Protein Polymers: Enhancing The Water Stability Property, Gowrishankar Srinivasan 2010 Iowa State University

Soy Protein Polymers: Enhancing The Water Stability Property, Gowrishankar Srinivasan

Graduate Theses and Dissertations

Soy protein based plastics have been processed in the past by researchers for various short-term applications; however a common issue is the high water sensitivity of these plastics. This work concentrates on resolving this water sensitivity issue of soy protein polymers by employing chemical and mechanical interaction at the molecular level during extrusion. The primary chemical interactions employed were anhydride chemistries such as maleic anhydride (MA), phthalic anhydride (PTA), and butylated hydroxyanisole (BHA). These were respectively used in conjunction with glycerol as a plasticizer to produce relatively water stable soy protein based plastics. Formulations with varying additive levels of the ...


The Yield Strength And Flow Stress Anomaly In B2 Yttrium Copper, Andrew Todd Becker 2010 Iowa State University

The Yield Strength And Flow Stress Anomaly In B2 Yttrium Copper, Andrew Todd Becker

Graduate Theses and Dissertations

The apparent yield strength anomaly in the B2 YCu intermetallic compound is shown not to be a yield point anomaly at all, but rather a phenomenon resulting from the work hardening behavior in YCu, which was found to rise with rising temperature and to drop with increases in strain rate. This effect is shown to occur over temperature ranges where YCu has negative strain rate sensitivity, result in dynamic strain ageing behavior, and the effect is shown to be irreversible when the testing temperature is changed. Neutron diffraction experiments utilizing SMARTS and HIPPO show the evolution of texture and the ...


Investigation Of Degradation In Polythiophene-Fullerene Based Solar Cells, Daniel Gene Putnam 2010 Iowa State University

Investigation Of Degradation In Polythiophene-Fullerene Based Solar Cells, Daniel Gene Putnam

Graduate Theses and Dissertations

This dissertation investigates the degradation of conjugated polymer poly(3-hexylthiophene) (P3HT). Specifically, exposure of polymer solutions to air and light, and aging of thin films in air and dark has been probed. Solutions of either P3HT or blend of P3HT and phenyl-C61-butyric acid methyl ester (PCBM) were mixed in air and light, and also in dark and inert atmosphere. Thin films of these solutions where then spin coated for UV-vis and Raman characterization. Hole only diodes and photovoltaic devices were also realized and characterized for mobility measurements and photovoltaic performance. Characterizations were repeated after aging the thin films in dark ...


Reducing Phase Noise Degradation Due To Vibration Of Crystal Oscillators, Cory Nelson 2010 Iowa State University

Reducing Phase Noise Degradation Due To Vibration Of Crystal Oscillators, Cory Nelson

Graduate Theses and Dissertations

In the radio communications industry, one major problem is the vibration induced on to a frequency standard. The most commonly used frequency standard is the crystal oscillator; as the crystal oscillator gets vibrated with varying force and frequencies of vibration the phase noise of the signal changes. As the phase noise increases, the signal to noise ratio decreases causing the likelihood of transmitting or receiving an incorrect signal to rise. This makes it critical to limit the phase noise increase that occurs in the frequency standard of the system.

Mechanical isolation systems have been implemented in the industry to limit ...


Medium Access Control And Network Planning In Wireless Networks, Zakhia Abichar 2010 Iowa State University

Medium Access Control And Network Planning In Wireless Networks, Zakhia Abichar

Graduate Theses and Dissertations

Wireless Local Area Networks (WLANs) and Wireless Metropolitan Area Networks (WMANs) are two of the main technologies in wireless data networks. WLANs have a short range and aim at providing connectivity to end users. On the other hand, WMANs have a long range and aim at serving as a backbone network and also at serving end users. In this dissertation, we consider the problem of Medium Access Control (MAC) in WLANs and the placement of Relay Stations (RSs) in WMANs. We propose a MAC scheme for WLANs in which stations contend by using jams on the channel. We present analytic ...


Dynamic Modeling And Ascent Flight Control Of Ares-I Crew Launch Vehicle, Wei Du 2010 Iowa State University

Dynamic Modeling And Ascent Flight Control Of Ares-I Crew Launch Vehicle, Wei Du

Graduate Theses and Dissertations

This research focuses on dynamic modeling and ascent flight control of large flexible launch vehicles such as the Ares–I Crew Launch Vehicle (CLV). A complete set of six–degrees–of–freedom dynamic models of the Ares–I, incorporating its propulsion, aerodynamics, guidance and control, and structural flexibility, is developed. NASA's Ares–I reference model and the SAVANT Simulink–based program are utilized to develop a Matlab–based simulation and linearization tool for an independent validation of the performance and stability of the ascent flight control system of large flexible launch vehicles. A linearized state–space model as well ...


Interlaminate Strength Of Laminated Die Tooling, Jenna Faith Pritchard 2010 Iowa State University

Interlaminate Strength Of Laminated Die Tooling, Jenna Faith Pritchard

Graduate Theses and Dissertations

This thesis examines process planning for rapid die tooling. Sheet metal die tooling typically requires long lead times from design to manufacturing. Rapid manufacturing of die tooling is a method that reduces lead times by minimizing the process planning time. This research focuses on the process planning algorithm for laminated die manufacture to automatically provide adequate interlaminate strength using a minimum number of fasteners.

A mechanical model was developed for predicting shear and compressive forces during sheet metal bending was developed as an input to a bolt and dowel pin algorithm. An algorithm is described for proper placement of bolts ...


An Investigation Of H2s Adsorption Mechanisms On Tire Derived Rubber Particles (TdrpTm), Ning Wang 2010 Iowa State University

An Investigation Of H2s Adsorption Mechanisms On Tire Derived Rubber Particles (TdrpTm), Ning Wang

Graduate Theses and Dissertations

Two commercial rubber waste products, tire derived rubber particle (TDRPTM) and other rubber material (ORMTM), were found to adsorb hydrogen sulfide gas (H2S) from biogas. A number of experiments were conducted to investigate the adsorption mechanism, surface properties and breakthrough characteristics. The physical properties, composition and surface chemistry were investigated and compared with commonly available commercial H2S adsorbents, such as activated carbon and metal oxide, in order to compare performance and to assess the possible adsorption mechanism. Additional effects on H2S adsorption capacity of TDRPTM and ORMTM were also studied ...


On Traffic Grooming And Survivability In Wdm Optical Networks, Long Long 2010 Iowa State University

On Traffic Grooming And Survivability In Wdm Optical Networks, Long Long

Graduate Theses and Dissertations

Wavelength-division multiplexing (WDM) technology allows an aggregate traffic on the order of Tbps to be carried on a single fiber, with each wavelength carrying traffic in the tens of Gbps order. However, the traffic requirements of most Internet applications are at much lower granularity compared with the extremely high bandwidth provided by WDM optical networks. Therefore, in order to utilize the network resources efficiently, a number of flows from multiple network connections with sub-wavelength granularities may be packed onto the same wavelength channel. This process refers to as traffic grooming.

The first part of this thesis is to address traffic ...


Evaluating The Cost And Performance Of Vegetative Treatment Systems On Open Beef Feedlots In The Midwestern United States, Bradley J. Bond 2010 Iowa State University

Evaluating The Cost And Performance Of Vegetative Treatment Systems On Open Beef Feedlots In The Midwestern United States, Bradley J. Bond

Graduate Theses and Dissertations

Runoff from open beef feedlots has become an important environmental concern over the last decade. Feedlot runoff has the potential to degrade surface water and groundwater. For these reasons, the U.S. Environmental Protection Agency required concentrated animal feeding operations (CAFOs) to control feedlot runoff resulting from up to and including a 25 year, 24 hour rainfall event. Typical feedlot runoff control systems utilize a containment basin to collect and store feedlot runoff.

In 2003, federal regulations allowed the use of alternative technologies to control feedlot runoff that performed equal to or better than a conventional runoff storage basin on ...


Food Traceability Information Modeling And Data Exchange And Gis Based Farm Traceability Model Design And Application, Hafize Gunsu Gemesi 2010 Iowa State University

Food Traceability Information Modeling And Data Exchange And Gis Based Farm Traceability Model Design And Application, Hafize Gunsu Gemesi

Graduate Theses and Dissertations

This thesis investigates the concept of electronic food traceability throughout the supply chain, with an emphasis on Traceable Resource Unit (TRU) identification, data management, and information exchange technologies from farm to fork. To accomplish these tasks, a UML (Unified Modeling Language) was used to create a product centric data model for managing TRU traceability data throughout the chain. After this step XML (Extensible Markup Language) schema was created using the UML model as a model foundation. The schema was used for the validation of XML files, which was written as an example of traceability information exchange and record keeping within ...


Lead-Free, Bronze-Based Surface Layers For Wear Resistance In Axial Piston Hydraulic Pumps, Greg Vetterick 2010 Iowa State University

Lead-Free, Bronze-Based Surface Layers For Wear Resistance In Axial Piston Hydraulic Pumps, Greg Vetterick

Graduate Theses and Dissertations

Concerns regarding the safety of lead have provided sufficient motivation to develop substitute materials for the surface layer on a thrust bearing type component known as a valve plate in axial piston hydraulic pumps that consists of 10% tin, 10% lead, and the remainder copper (in wt. %). A recently developed replacement material, a Cu-10Sn-3Bi (wt.%) P/M bronze, was found to be unsuitable as valve plate surface layer, requiring the development of a new alloy. A comparison of the Cu-10Sn-10Pb and Cu-10Sn-3Bi powder metal valve plates showed that the differences in wear behavior between the two alloys arose due to ...


Designing Effective And Efficient Incentive Policies For Renewable In Generation Expansion Planning, Ying Zhou 2010 Iowa State University

Designing Effective And Efficient Incentive Policies For Renewable In Generation Expansion Planning, Ying Zhou

Graduate Theses and Dissertations

We present a bilevel optimization approach to designing effective and efficient incentive policies for promoting renewable energy. The effectiveness of an incentive policy is its capability to achieve a goal that would not be achievable without it. Renewable

portfolio standard is used in this thesis as the policy goal. The efficiency of an incentive policy is measured by the amount of intervention, such as taxes collected and subsidies

paid, to achieve the policy goal. We obtain the most effective and efficient incentive policies in the context of generation expansion planning, in which a planner makes investment decisions to serve project ...


Real-Time Simulation Of Dynamic Vehicle Models Using High Performance Reconfigurable Computing Platforms, Madhu Monga 2010 Iowa State University

Real-Time Simulation Of Dynamic Vehicle Models Using High Performance Reconfigurable Computing Platforms, Madhu Monga

Graduate Theses and Dissertations

A software-based approach for Real-Time Simulation (RTS) may have difficulties in meeting real-time constraints for complex models. In this thesis, we present a methodology for the design and implementation of RTS algorithms, based on the use of Field-Programmable Gate Array (FPGA) technology to improve the response time of these models. Our methodology utilizes traditional Hardware/Software co-design approaches to generate a heterogeneous architecture for an FPGA-based simulator. We have optimized the hardware design such that it efficiently utilizes the parallel nature of FPGAs and pipelines the independent operations. Further enhancement is obtained through the use of custom accelerators for common ...


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