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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.
21

Tactical HF field expedient antenna performance /

Turkes, Gurkan. January 1990 (has links) (PDF)
Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, March 1990. / Thesis Advisor(s): Adler, Richard W. Second Reader: Jauregui, Stephen. "March 1990." Description based on signature pages as viewed on August 26, 2009. DTIC Identifier(s): Directional antennas, Computerized simulation, Tactical antennas, Buried radials, Elevated radials, High frequency, Lossy soils, Theses. Author(s) subject terms: Computer Simulation, Numerical Electromagnetics Code (NEC), Tactical HF Field Antennas. Includes bibliographical references. Also available online.
22

Simulation-Based Routing Protocols Analyses

Jaafar, Talal Mohamed 11 May 2007 (has links)
A new approach to distributed network simulations that eases the burdens on the simulation developer in creating space-parallel simulations is presented. It provides a full-topology knowledge for every federate (simulator instance) to make the best routing decision to destinations simulated at other federates. Later, this technique was used to characterize the benefits of IP Anycast mechanism at large scale. Different IP Anycast scenarios were simulated in a detailed Border Gateway Protocol (BGP) simulator using a realistic large-scale AS topology. Results indicated that Anycast indeed provides higher availability and decreased end-to-end delay. It also showed that Anycast does not provide load balancing, and the BGP overhead associated with a topology change is reduced when Anycast is deployed. In addition, a simulation model of Enhanced Interior Gateway Routing Protocol (EIGRP) was developed and used to present a new approach for host mobility within an AS. The new solution is to allow end systems to retain a fixed IP address as those systems move across subnet boundaries, and to use route advertisement updates (by EIGRP) to inform routers of new or revised routes to reach the mobile hosts as they migrate. The simulation results showed the viability of this approach, and the ability of EIGRP to update routing tables in a timely fashion.
23

A simulation model of Rio Grande wild turkey dynamics in the Edwards Plateau of Texas

Schwertner, Thomas Wayne 16 August 2006 (has links)
I investigated the effect of precipitation and predator abundance on Rio Grande wild turkey (Meleagris gallopavo; RGWT) in Texas. My results suggested that RGWT production was strongly correlated with cumulative winter precipitation over the range of the RGWT in Texas. However, I found no evidence that predator abundance influenced RGWT production, although spatial-asynchrony of predator populations at multiple spatial scales might have masked broad-scale effects. Using the results of these analyses, as well as empirical data derived from the literature and from field studies in the southern Edwards Plateau, I developed a stochastic, density-dependent, sex- and agespecific simulation model of wild turkey population dynamics. I used the model to evaluate the effect of alternative harvest management strategies on turkey populations. Sensitivity analysis of the model suggested that shape of the density-dependence relationship, clutch size, hatchability, juvenile sex ratio, poult survival, juvenile survival, and nonbreeding hen mortality most strongly influenced model outcome. Of these, density-dependence, sex ratio, and juvenile survival were least understood and merit further research. My evaluation of fall hen harvest suggested that current rates do not pose a threat to turkey populations. Moreover, it appears that hen harvest can be extended to other portions of the RGWT range without reducing turkey abundance, assuming that population dynamics and harvest rates are similar to those in the current fall harvest zone. Finally, simulation of alternative hen harvest rates suggested that rates ≥5% of the fall hen population resulted in significant declines in the simulated population after 25 years, and rates ≥15% resulted in significant risk of extinction to the simulated population.
24

Essays on horizontal merger simulation: the curse of dimensionality, retail price discrimination, and supply channel stage-games

Pofahl, Geoffrey Michael 25 April 2007 (has links)
In the words of Joel I. Klein, former Assistant Attorney General of the United States, “[a]ntitrust enforcement in the merger area has never been as time-consuming, complex, or as central to the functioning of our economy as it is today” (Klein, 1998). As such, the development of transparent, efficient, and accurate merger analysis tools is an endeavor whose value continues to increase in the eyes of regulators and industry participants alike. Arguably, the most visible result of such endeavors is the emergence and advancement of a practice known as merger simulation. The first goal of this dissertation is to evaluate the merits of the Distance Metric (DM) demand model and its usefulness in merger simulations. Revered by its creators as easy-to-use, flexible, and able to handle large numbers of products, the DM approach has not received the “road-testing” necessary for establishing its practical usefulness. The DM model is used to estimate demand elasticities for 45 bottled-juice products. Elasticities are then used to simulate numerous hypothetical mergers. While adding validity to the alleged strengths of the DM approach, an additional contribution is made by demonstrating the robustness of merger simulation results across 22 DM specifications. Despite the oft-recognized reality of zone pricing by food retailers, this form of price discrimination has received little attention within the context of upstream merger analysis. Thus, the second objective of this dissertation is to relax the conventional merger simulation assumption of uniform pricing by retailers, allowing us to explore the impacts of zone pricing on post-merger price effects. Using the ready-to-eat cereals industry as a backdrop, it is shown that ignoring retail price discrimination veils a potentially diverse set of price effects that are otherwise lost in uniform pricing analyses. The goal of the final essay is to explore the implementation of more realistic supply channel interactions in merger simulations. In particular, a two-stage pricing game is used to conduct merger simulations in the refrigerated orange juice category. The overriding finding is that comparisons with conventionally used models will not be practical until the relationship between demand specification and two-stage game modeling is better understood.
25

Volumetric particle modeling

Dingle, Brent Michael 17 September 2007 (has links)
This dissertation presents a robust method of modeling objects and forces for computer animation. Within this method objects and forces are represented as particles. As in most modeling systems, the movement of objects is driven by physically based forces. The usage of particles, however, allows more artistically motivated behavior to be achieved and also allows the modeling of heterogeneous objects and objects in different state phases: solid, liquid or gas. By using invisible particles to propagate forces through the modeling environment complex behavior is achieved through the interaction of relatively simple components. In sum, 'macroscopic' behavior emerges from 'microscopic' modeling. We present a newly developed modeling framework expanding on related work. This framework allows objects and forces to be modeled using particle representations and provides the details on how objects are created, how they interact, and how they may be displayed. We present examples to demonstrate the viability and robustness of the developed method of modeling. They illustrate the breaking and fracturing of solids, the interaction of objects in different phase states, and the achievement of a reasonable balance between artistic and physically based behaviors.
26

Numerische Simulation von Seegangs- und Windbelastung auf Offshore-Windkraftanlagen /

Corte, Carsten. January 1900 (has links) (PDF)
Techn. Universiẗat, Diss.--Braunschweig, 2006. / Auch als elektronisches Dokument.
27

Du modèle à la simulation informatique /

Varenne, Franck. January 2007 (has links)
Texte remanié de: Thèse de doctorat--Histoire--Lyon 2, 2004. Titre de soutenance : Le destin des formalismes. / Bibliogr. p. 213-234. Glossaire. Index.
28

Advanced research into moving target imaging using multistatic radar

Riedl, Grant H. January 2009 (has links) (PDF)
Thesis (M.S. in Applied Physics)--Naval Postgraduate School, December 2009. / Thesis Advisor: Borden, Brett. Second Reader: Walters, Donald. "December 2009." Description based on title screen as viewed on January 29, 2010. Author(s) subject terms: Moving Target Imaging, multistatic radar, computer simulation. Includes bibliographical references (p. 31). Also available in print.
29

Perception & role of 3-D visualizations in planning a case study of the Northwest Passage Scenic Byway's viewshed protection & visualization project /

Balke, Kyle. January 2010 (has links)
Thesis (MS)--University of Montana, 2010. / Contents viewed on February 4, 2010. Title from author supplied metadata. Includes bibliographical references.
30

Realistic evaluation of terrain by intelligent natural agents (RETINA) /

Burgess, René G. January 2003 (has links) (PDF)
Thesis (M.S. in Modeling, Virtual Environments and Simulation)--Naval Postgraduate School, September 2003. / Thesis advisor(s): Chris Darken, John Hiles. Includes bibliographical references (p. 87-90). Also available online.

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