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Full-Text Articles in Physical Sciences and Mathematics
The Absorption Spectrum Of The Hydrogen Atom In Crossed Electric And Magnetic Fields, Dongmei Wang
The Absorption Spectrum Of The Hydrogen Atom In Crossed Electric And Magnetic Fields, Dongmei Wang
Dissertations, Theses, and Masters Projects
This dissertation reports the theoretical interpretation of the measured absorption spectrum of hydrogen atoms in crossed electric and magnetic fields. Closed-orbit theory is modified from two-dimensions to three-dimensions to interpret the large scale structure in the absorption spectrum. A new computational method---a Chirped-Fourier-Transform---is developed to extract the closed orbits from an energy spectrum. A quantitative model is provided to calculate the continuum absorption. We prove that the observed continuum absorption is proportional to the flux of electrons along trajectories which escape within a short time. Einstein-Brillouin-Keller (EBK) quantization theory is applied to obtain an approximate energy spectrum. Our results prove …
Accelerating The Simulation Of Wireless Cellular Systems, Luiz Felipe Perrone
Accelerating The Simulation Of Wireless Cellular Systems, Luiz Felipe Perrone
Dissertations, Theses, and Masters Projects
The simulation of comprehensive models for cellular wireless systems poses a computational burden of great proportions. When a sub-model for transmitter power level control is included in the simulation, a continuous process in discrete-time is introduced, requiring traditional execution to advance in small, regular time-steps. to accelerate these simulations, we propose the use of interval jumping, a novel technique which allows time to progress in adaptive, irregularly-sized jumps in time. The foundations for this mechanism are laid out in the light of the simulation of a complex simulation model which includes teletraffic, radio propagation, channel allocation, transmitter power control, and …
Routing And Wavelength Assignment In Wdm Optical Networks, Guangzhi Li
Routing And Wavelength Assignment In Wdm Optical Networks, Guangzhi Li
Dissertations, Theses, and Masters Projects
In this thesis, we focus on the routing and wavelength assignment problems in WDM all-optical networks. Since the general problem is difficult (NP-complete), we classify the problem into several models with different formulations. Our objectives are to analyze some subclasses of routing and wavelength assignment problems; to understand their special properties; to estimate algorithm bounds and performance; and, to design efficient heuristic algorithms. These goals are important because results that follow can help engineers design efficient network topologies and protocols, and eventually provide end-users with cost-effective high bandwidth.;We first study the off-line wavelength assignment problem in single fiber ring and …
An Interactive Simulation Environment For End-To-End Digital Imaging System Design And Fidelity Analysis, Moira Joyce Turner
An Interactive Simulation Environment For End-To-End Digital Imaging System Design And Fidelity Analysis, Moira Joyce Turner
Dissertations, Theses, and Masters Projects
The detailed specification, implementation, and documentation of an interactive software environment based on a continuous/discrete/continuous imaging system model is presented. The purpose of the interactive environment is to support the design and performance analysis of end-to-end digital imaging systems. Development of the environment is based on the objectives of acceptable response time, large sampling grid capability, good graphical user interface design, independence from proprietary applications and portability among UNIX workstations. While one-dimensional variations of interactive design environments have been developed by the commercial active filter design community, there is little or no evidence that the increased complexity associated with the …
Semantic Software Scouts For Information Retrieval, John J. Rehder
Semantic Software Scouts For Information Retrieval, John J. Rehder
Dissertations, Theses, and Masters Projects
A new concept for information storage and retrieval is proposed that links chunks of information within and among documents based on semantic relationships and uses those connections to efficiently retrieve all the information that closely matches the user's request. The storage method is semantic hypertext, in which conventional hypertext links are enriched with semantic information that includes the strength and type of the relationship between the chunks of information being linked. A retrieval method was devised in which a set of cooperating software agents, called scouts, traverse the connections simultaneously searching for requested information. By communicating with each other and …
Data Structures For The Analysis Of Large Structured Markov Models, Andrew S. Miner
Data Structures For The Analysis Of Large Structured Markov Models, Andrew S. Miner
Dissertations, Theses, and Masters Projects
High-level modeling formalisms are increasingly popular tools for studying complex systems. Given a high-level model, we can automatically verify certain system properties or compute performance measures about the system. In the general case, measures must be computed using discrete-event simulations. In certain cases, exact numerical analysis is possible by constructing and analyzing the underlying stochastic process of the system, which is a continuous-time Markov chain (CTMC) in our case. Unfortunately, the number of states in the underlying CTMC can be extremely large, even if the high-level model is "small". In this thesis, we develop data structures and techniques that can …