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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Performance Evaluation of Cognitive Radios

Kaminski, Nicholas James 08 May 2012 (has links)
This thesis presents a performance evaluation system for cognitive radio. It considers performance as a complex, multi-dimensional function. Typically such a function would take some record of actions as an argument; however, a key contribution of this work is the addition of background information to the domain of the performance function. Including this information generalizes the performance function across many radios and applications, with the additional cost of complicating the domain. Thus the presented evaluation system organizes the domain information into sets. These sets are divided into two categories, one capturing necessary information that is external to the radio and on capturing necessary information that internal to the radio. These categories highlight the fact that neither the true actions nor the true performance is directly observable at the onset of evaluation. This arises because a cognitive radio can only express its actions in terms of the available knobs and meters, which together form the radio's language. Some understanding of this language and its limitations is required to fully understand the radio's expression of its actions. This parallelism of actions and performance suggests implementing the evaluation method as a composite form of the performance function. The composite performance function is made up of two sub-functions, one of which producing action information and one of which producing performance information. Specifically, the first sub-function is used to determine general measures of the actions' influence on performance; these are labeled Measures of Effectiveness. The second sub-function uses these Measures of Effectiveness to determine application specific performance values, called Measures of Performance. This work covers both these measures in detail. Each measure is determined as the result of a neural network based interpolation. This thesis also provides an examination of artificial neural networks in the scope of performance evaluation. Once these concepts are explored, a walk-through evaluation is presented. The four phases are the Setup Phase, the Logging Phase, the Training Phase, and the Evaluation Phase. Each phase is structured to provide the information necessary to determine the final performance. These phases detail the process of evaluation and discuss the realization of concepts explored earlier. This work concludes with a comparative evaluation example that proves the worth of the presented approach. A full evaluation system is outlined by this thesis and the foundational details for the system are explored in detail. / Master of Science
232

IN-CYLINDER CONDITION ESTIMATION AND CONTROL APPLICATIONS ON DIESEL ENGINE COMBUSTION

Chen, Song January 2016 (has links)
Advanced combustion modes offer promising solutions for both emission reduction and efficiency improvement. The lower local equivalence ratio and lower peak temperature characterized by the advanced combustion mode significantly reduce the generation of the engine-out emissions (especially the soot and NOx). Although the advanced combustion mode enjoys extra-low emissions, some technical challenges prevent it from being widely applied in real practice. Combustion phasing control as auto-ignition and narrow load range are two main challenges to be addressed. The estimation and control techniques for Diesel engine targeting these two challenges are presented in four papers in this thesis. Accessing to the in-cylinder conditions is essential for a more detailed combustion estimation and further combustion control. Paper 1 and Paper 2 (Chapter II and Chapter III) introduce methods of estimating two critical in-cylinder conditions, the in-cylinder temperature and oxygen concentration. The system dynamic models are derived and the Extended Kalman filter (EKF) and smooth variable structure filter (SVSF) are utilized for the in-cylinder temperature and in-cylinder oxygen concentration estimation, respectively. The method of coordinated control for the intake conditions and the combustion process aiming at a fast and accurate combustion process response is proposed in paper 3 (Chapter IV). Disturbance rejection control in conjunction with sliding mode method is proposed to control the air- and fuel-path loop simultaneously. As an indicator to show the combustion quality and to avoid significant incomplete combustion, the unburned fuel is estimated in paper 4 (Chapter V) based on the oxygen concentration. Three filters are designed to estimate the trapped unburned fuel and their robustness against modeling errors are analyzed and compared theoretically. / Dissertation / Doctor of Philosophy (PhD) / To ultimately reduce the engine-out emissions and increase the thermal efficiency, advanced combustion modes provide promising solutions. However, several obstacles, including the narrow load range and difficulty of the combustion phasing control, prevent the advanced combustion from being widely applied in practice. To address these obstacles, detail estimation of in-cylinder gas conditions and robust control for air- and fuel-path are critical. This thesis focuses on the states estimation and control for Diesel engines aiming to address the obstacles laid by the advanced combustion modes. Four journal papers with different objectives compose this thesis. Paper 1 and Paper 2 (Chapter II and III, respectively) propose methods of estimation of the in-cylinder temperature and oxygen concentration. Paper 3 (Chapter IV) introduces the method of coordinated control of the intake conditions and the combustion process. The unburned fuel is estimated in paper 4 (Chapter V). The techniques introduced in the 4 papers are either validated through calibrated GT-Power simulations or experiments in a Diesel engine.
233

Navigating Through Narratives: The Development of Opening Cinematics

Stewart, Jacob Q 01 December 2023 (has links) (PDF)
This project demonstrates opening cinematic design from conceptualization to final composition. Using Unreal Engine 5, I created an opening cutscene using Unreal’s sequencer editor to film and edit my shots. This document presents the steps I took to create my sequence from the writing process to the final layout. Starting as a written story, I worked my way to the final project by creating a mock scene and storyboarding. After this, I built my scene using assets from the Unreal marketplace and lit my scene with HDRI and dynamic lighting. I encountered many new programs such as Cascade and Mixamo to create and edit particle effects for my scene and animations for my protagonist character. I created unique sound effects for the level, recorded my shots with movement and color correction, and edited the final composition.
234

Development of Inexpensive Acquisition and Diagnostic Technique for Piston-Engine Aircraft

Thio, Tzer Hwai Gilbert 12 May 2001 (has links)
This paper presents an exploratory study of aircraft engine fault indicators obtained from sound and vibration recordings. Observing time sequence and frequency spectra of the recordings, a simple yet cost-effective method of detecting engine fault is achieved. A detailed discussion of the study performed, ranging from the hardware and software selection, initial tests, and discoveries made in the time domain and subsequently in the frequency domain will be presented.
235

Evaluation of an innovative high-temperature ceramic wafer seal for hypersonic engine applications

Steinetz, Bruce Michael January 1991 (has links)
No description available.
236

Dynamic analysis of free piston Stirling engines

Ulusoy, Necati January 1994 (has links)
No description available.
237

Multivariable Sliding Mode Control for Aircraft Engines

Sangwian, Sirirat 13 September 2011 (has links)
No description available.
238

Adaptive Sliding Mode Control for Aircraft Engines

Ebel, Kathryn C. 16 December 2011 (has links)
No description available.
239

Electronic Engine Controller Simulation and Emulation with Ethernet Connectivity

Blackann, Joshua A. 09 August 2011 (has links)
No description available.
240

Discovery Tool: A Framework for Accelerating Academic Collaborations

Kanjariya, Mitesh Mukesh 17 September 2013 (has links)
No description available.

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