Scaling Limit and Critical Exponents for Two-Dimensional Bootstrap Percolation

Consider a cellular automaton with state space $\{0,1 \}^{{\mathbb Z}^2}$ where the initial configuration $\omega_0$ is chosen according to a Bernoulli product measure, 1's are stable, and 0's become 1's if they are surrounded by at least three neighboring 1's. In this paper we show that the configuration $\omega_n$ at time n converges exponentially fast to a final configuration $\bar\omega$, and that the limiting measure corresponding to $\bar\omega$ is in the universality class of Bernoulli (independent) percolation. More precisely, assuming the existence of the critical exponents $\beta$, $\eta$, $\nu$ and $\gamma$, and of the continuum scaling limit of crossing probabilities for independent site percolation on the close-packed version of ${\mathbb Z}^2$ (i.e., for independent $*$-percolation on ${\mathbb Z}^2$), we prove that the bootstrapped percolation model has the same scaling limit and critical exponents. This type of bootstrap percolation can be seen as a paradigm for a class of cellular automata whose evolution is given, at each time step, by a monotonic and nonessential enhancement.Comment: 15 page

Letter from Joseph A. Camia, 1908-02-27, Boston, Mass., to Anne Whitney, Boston, Mass.

https://repository.wellesley.edu/whitney_correspondence/2506/thumbnail.jp

Exploring the Viability of Offering the Bachelor of Library and Information Science Program at Central Luzon State University, Philippines

The Bachelor of Library and Information Science (BLIS) program in the Philippines provides excellent employability due to its high demand in academia and other sectors. This study aimed to determine the viability of offering the Bachelor of Library and Information Science program at Central Luzon State University. The survey specifically sought to determine grade 11 students\u27 interest in enrolling in the program as well as its market employability in the academic sector in the region. Data were collected using a survey questionnaire from three public and three private neighboring high schools of Central Luzon State University as well as Google forms for higher education institutions. The data were described using the frequency count and percentage. SWOT analysis was also used to evaluate the institution\u27s advantage and capability to offer the program, as well as the program\u27s potential and direction. Findings present that the program is viable and the institution can sustain it. However, there are areas that should be strengthened and improved, as well as potential threats to the program\u27s continuation, such as a lack of awareness and poor performance on board examinations

Adaptation to Increasing Risks of Forest Fires

This work presents a quantitative assessment of adaptation options in the context of forest fires in Europe under projected climate change. A standalone fire model (SFM) based on a state-of-the-art, large-scale forest fire modeling algorithm is used to explore fuel removal through prescribed burnings and improved fire suppression as adaptation options. The climate change projections are provided by three climate models reflecting the SRES A2 scenario. The SFM’s modeled burned areas for selected test countries in Europe show satisfying agreement with observed data coming from two different sources (European Forest Fire Information System and Global Fire Emissions Database). Our estimation of the potential increase in burned areas in Europe under ‘‘no adaptation’’ scenario is about 200% by 2090 (compared with 2000-2008). The application of prescribed burnings has the potential to keep that increase below 50%. Improvements in fire suppression might reduce this impact even further, for example, boosting the probability of putting out a fire within a day by 10% would result in about a 30% decrease in annual burned areas. By taking more adaptation options into consideration, such as using agricultural fields as fire breaks, behavioral changes, and long-term options, burned areas can be potentially reduced even further

Free and Open Source Software underpinning the European Forest Data Centre

Worldwide, governments are growingly focusing on free and open source software (FOSS) as a move toward transparency and the freedom to run, copy, study, change and improve the software. The European Commission (EC) is also supporting the development of FOSS [...]. In addition to the financial savings, FOSS contributes to scientific knowledge freedom in computational science (CS) and is increasingly rewarded in the science-policy interface within the emerging paradigm of open science. Since complex computational science applications may be affected by software uncertainty, FOSS may help to mitigate part of the impact of software errors by CS community- driven open review, correction and evolution of scientific code. The continental scale of EC science-based policy support implies wide networks of scientific collaboration. Thematic information systems also may benefit from this approach within reproducible integrated modelling. This is supported by the EC strategy on FOSS: "for the development of new information systems, where deployment is foreseen by parties outside of the EC infrastructure, [F]OSS will be the preferred choice and in any case used whenever possible". The aim of this contribution is to highlight how a continental scale information system may exploit and integrate FOSS technologies within the transdisciplinary research underpinning such a complex system. A European example is discussed where FOSS innervates both the structure of the information system itself and the inherent transdisciplinary research for modelling the data and information which constitute the system content. [...

Metastability in zero-temperature dynamics: Statistics of attractors

The zero-temperature dynamics of simple models such as Ising ferromagnets provides, as an alternative to the mean-field situation, interesting examples of dynamical systems with many attractors (absorbing configurations, blocked configurations, zero-temperature metastable states). After a brief review of metastability in the mean-field ferromagnet and of the droplet picture, we focus our attention onto zero-temperature single-spin-flip dynamics of ferromagnetic Ising models. The situations leading to metastability are characterized. The statistics and the spatial structure of the attractors thus obtained are investigated, and put in perspective with uniform a priori ensembles. We review the vast amount of exact results available in one dimension, and present original results on the square and honeycomb lattices.Comment: 21 pages, 6 figures. To appear in special issue of JPCM on Granular Matter edited by M. Nicodem

Metadata Model for the European Forest Information and Communication Platform

This paper describes the metadata model conceived for the future European Forest Information and Communication Platform (EFICP). The core of the platform, currently under implementation in the scope of a two-year project funded by the European Commission, is given by a repository of metadata that describes the available information resources. These are distinguished in terms of resource categories (common / bibliographic resources, news, spatial data information services and statistical data) and are treated in a differentiated way by the EFICP metadata model, applying widely accepted standards such as ISO/OGC, Dublin Core, SDMX and RSS, whereas a key requirement for system interoperability is given by the set of INSPIRE implementation rules as currently available. This paper provides a description of the structure of the EFICP metadata model and its components. This model extends the metadata guidelines as proposed by the former NEFIS project. In order to support the online access and exchange of forestry specific statistical data, a general information model for the modelling of these resources in the context of a proposed EFICP reference reporting system has been created and is proposed for implementation on the basis of the SDMX standard. Keywords: metadata, Dublin Core, OGC, search and discovery, geospatial information services, forestry statistics, EFICS, EFIC