275 research outputs found
Automated environmental control of an acoustic test facility, part A Final project report
Mathematical models for automated environmental control of acoustic test facility inside chambe
Fourier and statistical analysis at random waveforms, part D Final project report
Computer programming formulas for frequency and statistical analysis of random waveform signals including Fourier analysis, probability density functions, and autocorrelatio
Identification of a linear system from sampled noisy data, part C Final project report
Step input linear system modeling from nonlinear system sampled noisy data based on method of perturbation or quasilinearization of automatic control system dat
Inverse problems in partial differential equations
Identification in partial differential equations by Laplace equatio
Cyber Defense Competition Card Game
Cyber Defense Competition Game is a JavaScript web application used to represent a card game version of a Cyber Defense Competition online. Cyber Defense Competitions have often been used to teach the concepts of information security and have participants compete against each other to protect their assets. This game attempts to create many of the same experiences that could be had during a Cyber Defense Competition but without much of the setup and taking much less time.
This project is the first step towards an easily playable card game between two players and a moderator. This version of the game was created to be easily modified and understood so that future developers can make changes depending on user testing results
An optimal controller based on linear approximation of an acoustical test facility, part B Final report
Optimal digital controller based on linear approximation of acoustical test facility, for determining effects of supersonic rocket engine noise on vehicle surfac
Can Track and Field’s Governing Body Ban Female Runners From Competing in the U.S. Because of High Testosterone Levels?
This article explores the applicability, if any, in the United States of a decision rendered by a private sports arbitration organization in Lausanne, Switzerland: the Court of Arbitration for Sport (CAS). The decision validated regulations of World Athletics—the private organization that governs track and field internationally—which had the effect of banning an Olympic champion, Caster Semenya of South Africa, from international competition against females because she had testosterone levels that World Athletics deemed too high. The article focuses on the fact that the CAS decision uses the law of Monaco to decide the matter. CAS specifically states that the decision may not apply in other countries like the U.S. CAS expressly leaves such decisions to the courts of the respective countries involved. The article then explores the reasoning of CAS with respect to both the U.S. law of discrimination and the law of evidence. The article concludes that the CAS decision would not stand up under either set of laws in the United States. In particular, most of the evidence relied on by CAS would not be admissible in U.S. courts because of the standards set in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), that prohibit expert testimony not in accord with generally accepted scientific standards
Global Production Increased by Spatial Heterogeneity in a Population Dynamics Model
Spatial and temporal heterogeneity are often described as important factors having a strong impact on biodiversity. The effect of heterogeneity is in most cases analyzed by the response of biotic interactions such as competition of predation. It may also modify intrinsic population properties such as growth rate. Most of the studies are theoretic since it is often difficult to manipulate spatial heterogeneity in practice. Despite the large number of studies dealing with this topics, it is still difficult to understand how the heterogeneity affects populations dynamics. On the basis of a very simple model, this paper aims to explicitly provide a simple mechanism which can explain why spatial heterogeneity may be a favorable factor for production.We consider a two patch model and a logistic growth is assumed on each patch. A general condition on the migration rates and the local subpopulation growth rates is provided under which the total carrying capacity is higher than the sum of the local carrying capacities, which is not intuitive. As we illustrate, this result is robust under stochastic perturbations
Local enrichment and its nonlocal consequences for victim-exploiter metapopulations
The stabilizing effects of local enrichment are revisited. Diffusively
coupled host-parasitoid and predator-prey metapopulations are shown to admit a
stable fixed point, limit cycle or stable torus with a rich bifurcation
structure. A linear toy model that yields many of the basic qualitative
features of this system is presented. The further nonlinear complications are
analyzed in the framework of the marginally stable Lotka-Volterra model, and
the continuous time analog of the unstable, host-parasitoid Nicholson-Bailey
model. The dependence of the results on the migration rate and level of spatial
variations is examined, and the possibility of "nonlocal" effect of enrichment,
where local enrichment induces stable oscillations at a distance, is studied. A
simple method for basic estimation of the relative importance of this effect in
experimental systems is presented and exemplified.Comment: 25 pages, 13 figures, to appear physica D 200
Long-term cyclic persistence in an experimental predator–prey system
Predator–prey cycles rank among the most fundamental concepts in ecology, are predicted by the simplest ecological models and enable, theoretically, the indefinite persistence of predator and prey1,2,3,4. However, it remains an open question for how long cyclic dynamics can be self-sustained in real communities. Field observations have been restricted to a few cycle periods5,6,7,8 and experimental studies indicate that oscillations may be short-lived without external stabilizing factors9,10,11,12,13,14,15,16,17,18,19. Here we performed microcosm experiments with a planktonic predator–prey system and repeatedly observed oscillatory time series of unprecedented length that persisted for up to around 50 cycles or approximately 300 predator generations. The dominant type of dynamics was characterized by regular, coherent oscillations with a nearly constant predator–prey phase difference. Despite constant experimental conditions, we also observed shorter episodes of irregular, non-coherent oscillations without any significant phase relationship. However, the predator–prey system showed a strong tendency to return to the dominant dynamical regime with a defined phase relationship. A mathematical model suggests that stochasticity is probably responsible for the reversible shift from coherent to non-coherent oscillations, a notion that was supported by experiments with external forcing by pulsed nutrient supply. Our findings empirically demonstrate the potential for infinite persistence of predator and prey populations in a cyclic dynamic regime that shows resilience in the presence of stochastic events
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