906 resultados para Complex systems prediction


Relevância:

80.00% 80.00%

Publicador:

Resumo:

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The new computing paradigm known as cognitive computing attempts to imitate the human capabilities of learning, problem solving, and considering things in context. To do so, an application (a cognitive system) must learn from its environment (e.g., by interacting with various interfaces). These interfaces can run the gamut from sensors to humans to databases. Accessing data through such interfaces allows the system to conduct cognitive tasks that can support humans in decision-making or problem-solving processes. Cognitive systems can be integrated into various domains (e.g., medicine or insurance). For example, a cognitive system in cities can collect data, can learn from various data sources and can then attempt to connect these sources to provide real time optimizations of subsystems within the city (e.g., the transportation system). In this study, we provide a methodology for integrating a cognitive system that allows data to be verbalized, making the causalities and hypotheses generated from the cognitive system more understandable to humans. We abstract a city subsystem—passenger flow for a taxi company—by applying fuzzy cognitive maps (FCMs). FCMs can be used as a mathematical tool for modeling complex systems built by directed graphs with concepts (e.g., policies, events, and/or domains) as nodes and causalities as edges. As a verbalization technique we introduce the restriction-centered theory of reasoning (RCT). RCT addresses the imprecision inherent in language by introducing restrictions. Using this underlying combinatorial design, our approach can handle large data sets from complex systems and make the output understandable to humans.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The paper revives a theoretical definition of party coherence as being composed of two basic elements, cohesion and factionalism, to propose and apply a novel empirical measure based on spin physics. The simultaneous analysis of both components using a single measurement concept is applied to data representing the political beliefs of candidates in the Swiss general elections of 2003 and 2007, proposing a connection between the coherence of the beliefs party members hold and the assessment of parties being at risk of splitting. We also compare our measure with established polarization measures and demonstrate its advantage with respect to multi-dimensional data that lack clear structure. Furthermore, we outline how our analysis supports the distinction between bottom-up and top-down mechanisms of party splitting. In this way, we are able to turn the intuition of coherence into a defined quantitative concept that, additionally, offers a methodological basis for comparative research of party coherence. Our work serves as an example of how a complex systems approach allows to get a new perspective on a long-standing issue in political science.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Detracking and heterogeneous groupwork are two educational practices that have been shown to have promise for affording all students needed learning opportunities to develop mathematical proficiency. However, teachers face significant pedagogical challenges in organizing productive groupwork in these settings. This study offers an analysis of one teacher’s role in creating a classroom system that supported student collaboration within groups in a detracked, heterogeneous geometry classroom. The analysis focuses on four categories of the teacher’s work that created a set of affordances to support within group collaborative practices and links the teacher’s work with principles of complex systems.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Recent developments in federal policy have prompted the creation of state evaluation frameworks for principals and teachers that hold educators accountable for effective practices and student outcomes. These changes have created a demand for formative evaluation instruments that reflect current accountability pressures and can be used by schools to focus school improvement and leadership development efforts. The Comprehensive Assessment of Leadership for Learning (CALL) is a next generation, 360-degree on-line assessment and feedback system that reflect best practices in feedback design. Some unique characteristics of CALL include a focus on: leadership distributed throughout the school rather than as carried out by an individual leader; assessment of leadership tasks rather than perceptions of leadership practice; a focus on larger complex systems of middle and high school; and transparency of assessment design. This paper describes research contributing to the design and validation of the CALL survey instrument.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Nuestro trabajo tiene como objetivo aplicar conceptos de la teoría de los sistemas complejos y herramientas del análisis de redes sociales para describir y analizar el surgimiento y la evolución de una red social conformada por científicos, docentes, graduados y funcionarios públicos de diferentes organismos científicos y académicos, que crearon y participaron de un equipo multidisciplinario que elaboró un informe sobre un proyecto de ley de Ordenamiento Territorial y Usos del Suelo de la provincia de Mendoza en el año 2006. Para la compresión de la evolución del proceso de elaboración del proyecto de ley de ordenamiento territorial y de usos del suelo, organizaremos la estructura del trabajo de la siguiente manera: - Primero aplicaremos aspectos teóricos y metodológicos, basados en la sistematización realizada por Rolando García en su libro “Sistemas Complejos. Conceptos, método y fundamentación epistemológica de la investigación interdisciplinaria", para realizar el recorte del sistema objeto de estudio. - En segundo lugar utilizaremos la Teoría de Análisis de Redes Sociales para describir la composición y estructura del sistema (nodos y vínculos) en cada momento. La estructura del sistema en cada momento significativo será graficada por medio el Software Ucinet 6 y NetDraw. - Por último, haremos referencia a las dificultades que tuvo el proceso desde el punto de vista de las condicionalidades que generaban los modelos mentales que portaban los participantes.

Relevância:

80.00% 80.00%

Publicador:

Relevância:

80.00% 80.00%

Publicador:

Relevância:

80.00% 80.00%

Publicador:

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The micro-scale spatial distribution patterns of a demersal fish and decapod crustacean assemblage were assessed in a hard-bottom kelp environment in the southern North Sea. Using quadrats along line transects, we assessed the in situ fish and crustacean abundance in relation to substratum types (rock, cobbles and large pebbles) and the density of algae. Six fish and four crustacean species were abundant, with Ctenolabrus rupestris clearly dominating the fish community and Galathea squamifera dominating the crustacean community. Differences in the substratum types had an even stronger effect on the micro-scale distribution than the density of the dominating algae species. Kelp had a negative effect on the fish abundances, with significantly lower average densities in kelp beds compared with adjacent open areas. Averaged over all of the substrata, the most attractive substratum for the fish was large pebbles. In contrast, crustaceans did not show a specific substratum affinity. The results clearly indicate that, similar to other complex systems, significant micro-scale species-habitat associations occur in northern hard-bottom environments. However, because of the frequently harsh environmental conditions, these habitats are mainly sampled from ships with sampling gear, and the resulting data cannot be used to resolve small-scale species-habitat associations. A detailed substratum classification and community assessment, often only possible using SCUBA diving, is therefore important to reach a better understanding of the functional relationships between species and their environment in northern temperate waters, knowledge that is very important with respect to the increasing environmental pressure caused by global climate change.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

As the atmospheric CO2 concentration rises, more CO2 will dissolve in the oceans, leading to a reduction in pH. Effects of ocean acidification on bacterial communities have mainly been studied in biologically complex systems, in which indirect effects, mediated through food web interactions, come into play. These approaches come close to nature but suffer from low replication and neglect seasonality. To comprehensively investigate direct pH effects, we conducted highly-replicated laboratory acidification experiments with the natural bacterial community from Helgoland Roads (North Sea). Seasonal variability was accounted for by repeating the experiment four times (spring, summer, autumn, winter). Three dilution approaches were used to select for different ecological strategies, i.e. fast-growing or low-nutrient adapted bacteria. The pH levels investigated were in situ seawater pH (8.15-8.22), pH 7.82 and pH 7.67, representing the present-day situation and two acidification scenarios projected for the North Sea for the year 2100. In all seasons, both automated ribosomal intergenic spacer analysis and 16S ribosomal amplicon pyrosequencing revealed pH-dependent community shifts for two of the dilution approaches. Bacteria susceptible to changes in pH were different members of Gammaproteobacteria, Flavobacteriaceae, Rhodobacteraceae, Campylobacteraceae and further less abundant groups. Their specific response to reduced pH was often context-dependent. Bacterial abundance was not influenced by pH. Our findings suggest that already moderate changes in pH have the potential to cause compositional shifts, depending on the community assembly and environmental factors. By identifying pH-susceptible groups, this study provides insights for more directed, in-depth community analyses in large-scale and long-term experiments.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The Global River Discharge (RivDIS) data set contains monthly discharge measurements for 1018 stations located throughout the world. The period of record varies widely from station to station, with a mean of 21.5 years. These data were digitized from published UNESCO archives by Charles Voromarty, Balaze Fekete, and B.A. Tucker of the Complex Systems Research Center (CSRC) at the University of New Hampshire. River discharge is typically measured through the use of a rating curve that relates local water level height to discharge. This rating curve is used to estimate discharge from the observed water level. The rating curves are periodically rechecked and recalibrated through on-site measurement of discharge and river stage.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The modelling of critical infrastructures (CIs) is an important issue that needs to be properly addressed, for several reasons. It is a basic support for making decisions about operation and risk reduction. It might help in understanding high-level states at the system-of-systems layer, which are not ready evident to the organisations that manage the lower level technical systems. Moreover, it is also indispensable for setting a common reference between operator and authorities, for agreeing on the incident scenarios that might affect those infrastructures. So far, critical infrastructures have been modelled ad-hoc, on the basis of knowledge and practice derived from less complex systems. As there is no theoretical framework, most of these efforts proceed without clear guides and goals and using informally defined schemas based mostly on boxes and arrows. Different CIs (electricity grid, telecommunications networks, emergency support, etc) have been modelled using particular schemas that were not directly translatable from one CI to another. If there is a desire to build a science of CIs it is because there are some observable commonalities that different CIs share. Up until now, however, those commonalities were not adequately compiled or categorized, so building models of CIs that are rooted on such commonalities was not possible. This report explores the issue of which elements underlie every CI and how those elements can be used to develop a modelling language that will enable CI modelling and, subsequently, analysis of CI interactions, with a special focus on resilience