31,674 research outputs found
Case record analysis
It is argued that the determinates of low frequency (less than once an hour) challenging behavior are likely to be more complex than those of high frequency behavior involving setting events that may not be present when the behavior occurs. The analysis of case records is then examined as a method of identifying possible setting events to low frequency behaviours. It is suggested that time series analysis, correlational analysis and time lag sequential analysis may all be useful methods in the examination of case records
Causality detection and turbulence in fusion plasmas
This work explores the potential of an information-theoretical causality
detection method for unraveling the relation between fluctuating variables in
complex nonlinear systems. The method is tested on some simple though nonlinear
models, and guidelines for the choice of analysis parameters are established.
Then, measurements from magnetically confined fusion plasmas are analyzed. The
selected data bear relevance to the all-important spontaneous confinement
transitions often observed in fusion plasmas, fundamental for the design of an
economically attractive fusion reactor. It is shown how the present method is
capable of clarifying the interaction between fluctuating quantities such as
the turbulence amplitude, turbulent flux, and Zonal Flow amplitude, and
uncovers several interactions that were missed by traditional methods.Comment: 26 pages, 14 figure
Action and semantics of time in agro-ecology
In the systemic approach, the system is perceived as an action or a collection of overlapping actions expressed in reference to Time, Space, and Morphology (or Energy). When the system is studied by different disciplines, the referentials differ, as well as the semantics of terms used to describe the action. In order to establish the vocabulary of a collection of actions involving several disciplines, we propose a formal method for describing each action. The linguistic-based method enables (i) transcription of the literal description of an action in a semantic network, and (ii) building of a vocabulary in a formal setting. The method is illustrated through a complex biological system, i.e. the mutualistic relationship between two vine pests, while focusing particularly on temporality. The method provides a support for implementing multidisciplinary around a complex system. (Résumé d'auteur
Social protection and economic growth in the Sudan: Trends, perspectives, cointegration and causality
This paper takes into account the recent role of social protection on economic growth as a socio-economic-political stabilizer. Social protection outcome in Sudan is influenced by limited targeting actions with very low interventions between results in economic growth and accesses to basic social services. These may affects the social protection contributes to the process of development in the Sudan during the period under consideration. The results show that more social spending increase output which enhances GDP per capita growth by 0.5% with 3.1% towards convergence equilibrium in the long run. Moreover, universal approach and expanded cover to social protection services which aim at building a social protection as a productive factor may have contributed to enhancing income security, education and health outcomes, reducing the poverty, income inequality, socio-political stability, encouraged poor productive activities and enhancing economic growth lead to sustainable development.Social Protection, Growth, Cointegration, causality, Sudan
Understanding the effects of violent video games on violent crime
Psychological studies invariably find a positive relationship between violent video game play and aggression. However, these studies cannot account for either aggressive effects of alternative activities video game playing substitutes for or the possible selection of relatively violent people into playing violent video games. That is, they lack external validity. We investigate the relationship between the prevalence of violent video games and violent crimes. Our results are consistent with two opposing effects. First, they support the behavioral effects as in the psychological studies. Second, they suggest a larger voluntary incapacitation effect in which playing either violent or non-violent games decrease crimes. Overall, violent video games lead to decreases in violent crime. --Video Games,Violence,Crime
Constructing Time Machines
The existence of time machines, understood as spacetime constructions
exhibiting physically realised closed timelike curves (CTCs), would raise
fundamental problems with causality and challenge our current understanding of
classical and quantum theories of gravity. In this paper, we investigate three
proposals for time machines which share some common features: cosmic strings in
relative motion, where the conical spacetime appears to allow CTCs; colliding
gravitational shock waves, which in Aichelburg-Sexl coordinates imply
discontinuous geodesics; and the superluminal propagation of light in
gravitational radiation metrics in a modified electrodynamics featuring
violations of the strong equivalence principle. While we show that ultimately
none of these constructions creates a working time machine, their study
illustrates the subtle levels at which causal self-consistency imposes itself,
and we consider what intuition can be drawn from these examples for future
theories.Comment: 36 pages, 14 figures, TeX with harvmac; Review article prepared for
Int. J. Mod. Phys.
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