948 resultados para information sciences


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Geoportal allows users to find, search and share data.

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Adaptability and invisibility are hallmarks of modern terrorism, and keeping pace with its dynamic nature presents a serious challenge for societies throughout the world. Innovations in computer science have incorporated applied mathematics to develop a wide array of predictive models to support the variety of approaches to counterterrorism. Predictive models are usually designed to forecast the location of attacks. Although this may protect individual structures or locations, it does not reduce the threat—it merely changes the target. While predictive models dedicated to events or social relationships receive much attention where the mathematical and social science communities intersect, models dedicated to terrorist locations such as safe-houses (rather than their targets or training sites) are rare and possibly nonexistent. At the time of this research, there were no publically available models designed to predict locations where violent extremists are likely to reside. This research uses France as a case study to present a complex systems model that incorporates multiple quantitative, qualitative and geospatial variables that differ in terms of scale, weight, and type. Though many of these variables are recognized by specialists in security studies, there remains controversy with respect to their relative importance, degree of interaction, and interdependence. Additionally, some of the variables proposed in this research are not generally recognized as drivers, yet they warrant examination based on their potential role within a complex system. This research tested multiple regression models and determined that geographically-weighted regression analysis produced the most accurate result to accommodate non-stationary coefficient behavior, demonstrating that geographic variables are critical to understanding and predicting the phenomenon of terrorism. This dissertation presents a flexible prototypical model that can be refined and applied to other regions to inform stakeholders such as policy-makers and law enforcement in their efforts to improve national security and enhance quality-of-life.

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The Toledo Gate of Ciudad Real, Spain, constructed between the late 13th and early 14th centuries, is the last remaining portion of a once complete medieval city wall. It represents the long history of the city and constitutes its main heritage symbol, dividing the historic city centre from the later 19th and 20th century expansions. In October 2012, the Town Hall and the Montemadrid Foundation started the conservation works to preserve this important monument. The preliminary phase of this project included an in-depth series of scientific studies which were carried out by a multidisciplinary team focusing on archival research, historic investigations, archaeological excavations as well as material composition analysis and main treatment application tests. As a result of these studies a series of virtual 3D models were created to inform, discuss and study the monument. A first digital model permitted visualization of the gate in the 19th century and how the main entrance to the city was integrated as a fundamental part of the city walls. This virtual reconstruction also became an important part of the campaign to raise awareness among the citizens towards a monument that had remained in the shadows for the last century, isolated in a roundabout after the systematic demolition of the city walls in the late 19th century. Over the last three years and as a result of these archaeological and historic investigations and subsequent virtual models, surprisingly new and interesting data were brought to light thus permitting the establishment and corroboration of a new and updated hypothesis of the Toledo Gate that goes beyond the previous ideas. As a result of these studies a new architectural typology with construction techniques of has been suggested. This paper describes how the results of this continuous and interdisciplinary documentation process have benefitted from a computer graphic reconstruction of the gate. It highlights how virtual reconstruction can be a powerful tool for conservation decision making and awareness raising. Furthermore, the interesting results of the final reconstruction hypothesis convinced the technical team responsible for the conservation to alter some aspects of the final project physical interventions in order to focus on some of the features and conclusions discovered through the virtual model study.

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Las organizaciones y sus entornos son sistemas complejos. Tales sistemas son difíciles de comprender y predecir. Pese a ello, la predicción es una tarea fundamental para la gestión empresarial y para la toma de decisiones que implica siempre un riesgo. Los métodos clásicos de predicción (entre los cuales están: la regresión lineal, la Autoregresive Moving Average y el exponential smoothing) establecen supuestos como la linealidad, la estabilidad para ser matemática y computacionalmente tratables. Por diferentes medios, sin embargo, se han demostrado las limitaciones de tales métodos. Pues bien, en las últimas décadas nuevos métodos de predicción han surgido con el fin de abarcar la complejidad de los sistemas organizacionales y sus entornos, antes que evitarla. Entre ellos, los más promisorios son los métodos de predicción bio-inspirados (ej. redes neuronales, algoritmos genéticos /evolutivos y sistemas inmunes artificiales). Este artículo pretende establecer un estado situacional de las aplicaciones actuales y potenciales de los métodos bio-inspirados de predicción en la administración.

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José Rodrigues Santos de Sousa Ramos, mathematician of great merit, passed away on January 1st, 2007, in Lisbon. He was buried in Sobral da Adiça. His death was a huge loss for the development of mathematics in Portugal. The course of time will increase the dimension of this loss. Therefore, we dedicated this theme issue on Dynamical Systems to recall his memory and underline his work. We never forget you.

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In this work we analyze an optimal control problem for a system of two hydroelectric power stations in cascade with reversible turbines. The objective is to optimize the profit of power production while respecting the system’s restrictions. Some of these restrictions translate into state constraints and the cost function is nonconvex. This increases the complexity of the optimal control problem. The problem is solved numerically and two different approaches are adopted. These approaches focus on global optimization techniques (Chen-Burer algorithm) and on a projection estimation refinement method (PERmethod). PERmethod is used as a technique to reduce the dimension of the problem. Results and execution time of the two procedures are compared.

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Este artículo es resultado del seguimiento a graduados de la carrera de Ciencias Geográficas desde el año 2005. El objetivo general se centró en analizar las tareas que realizan los geógrafos para establecer la correspondencia con el perfil del graduado. Se identificaron 16 líneas de trabajo y las tareas realizadas en cada una de éstas, desde la perspectiva de los graduados. Los resultados indican que el área que emplea mayor número de geógrafos es Ciencias de la Información Geográfica; en tanto el área de enseñanza y divulgación de la Geografía ofrece una oportunidad de complementar el empleo principal. Los empleadores destacan como fortalezas de los geógrafos la formación humanista y en Ciencias de la Información Geográfica, Paisaje, Territorio y Recursos Naturales, Gestión y Ordenamiento del Territorio. Se concluye que las tareas realizadas son congruentes con el perfil del graduado del plan de estudio de la carrera.Palabras claves: Líneas de  trabajo del geógrafo, mercado  laboral del geógrafo, carrera de Ciencias Geográficas Universidad Nacional, seguimiento a graduados, perfil del graduado. AbstractThis article is the result of monitoring graduates who started their careers in geographic sciences from the year 2005. Sixteen jobs and the functions of each of these were identified, from the perspective of the graduates. The general objective centered on analyzing the tasks the geographers performed in order to establish the relationship with the graduate profile.The results indicated that the major field of employment is Geographical Information Sciences, meanwhile the field of teaching and publishing offer an opportunity to complement the primary job. The employers emphasized the humanistic formation and geographic information sciences, landscape, land and natural resources, land management and zoning. It concluded that the tasks carried out are congruent with the profile of the graduateʼs plan of course study. Key Words: Lines of work for geographers, labor market for geographers, Geographical Sciences degree, Universidad Nacional, graduate monitoring, graduate profile.

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Monitoring agricultural crops constitutes a vital task for the general understanding of land use spatio-temporal dynamics. This paper presents an approach for the enhancement of current crop monitoring capabilities on a regional scale, in order to allow for the analysis of environmental and socio-economic drivers and impacts of agricultural land use. This work discusses the advantages and current limitations of using 250m VI data from the Moderate Resolution Imaging Spectroradiometer (MODIS) for this purpose, with emphasis in the difficulty of correctly analyzing pixels whose temporal responses are disturbed due to certain sources of interference such as mixed or heterogeneous land cover. It is shown that the influence of noisy or disturbed pixels can be minimized, and a much more consistent and useful result can be attained, if individual agricultural fields are identified and each field's pixels are analyzed in a collective manner. As such, a method is proposed that makes use of image segmentation techniques based on MODIS temporal information in order to identify portions of the study area that agree with actual agricultural field borders. The pixels of each portion or segment are then analyzed individually in order to estimate the reliability of the temporal signal observed and the consequent relevance of any estimation of land use from that data. The proposed method was applied in the state of Mato Grosso, in mid-western Brazil, where extensive ground truth data was available. Experiments were carried out using several supervised classification algorithms as well as different subsets of land cover classes, in order to test the methodology in a comprehensive way. Results show that the proposed method is capable of consistently improving classification results not only in terms of overall accuracy but also qualitatively by allowing a better understanding of the land use patterns detected. It thus provides a practical and straightforward procedure for enhancing crop-mapping capabilities using temporal series of moderate resolution remote sensing data.

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The paper viewed the decline in information provision in Nigeria to poor library development, which could be attributed to poor funding. The consequence is that current journal and books are not available in nigerian fisheries libraries. Information which can be regarded as the first factor of production on which other factors like land, labour and capital depend, can only be provided at the right time when libraries are better founded. For now if there must be increase in fish production, poverty alleviation and food security in Nigeria, our fisheries scientists and policy makers will have to rely on international sources of information using the advantage of internet connectivity. Some of such sources discussed in this paper are ASFA, AGORA, FAO DOAJ, FISHBASE, IAMSLIC, INASP, INASP-PERI, INASP-AJOL, ODINAFRICA, SIFAR, WAS, and ABASFR. However, reliance on international sources must not be at the total neglect of harnessing nigerian fisheries information. For the Nigerian Fisheries and Aquatic Sciences Database being developed by NIFFR to attain an international status like those enumerated above, scientists and publishers are requested to take the pain of depositing copies of their publications with NIFFR for inclusion in the Database

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Ce rapport constitue une version augmentée d’un premier rapport datant d’août 2005. Les 21 fiches annotées peuvent aussi être consultées individuellement (en format HTML) à partir du « Portail des ressources pédagogiques et disciplinaires en sciences de l'information » accessible à l’adresse : http://www.ebsi.umontreal.ca/clip/

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Objective: To portray an information literacy programme demonstrating a high level of integration in health sciences curricula and a teaching orientation aiming towards the development of lifelong learning skills. The setting is a French-speaking North American university. Methods: The offering includes standard workshops such as MEDLINE searching and specialised sessions such as pharmaceutical patents searching. A contribution to an international teaching collaboration in Haiti where workshops had to be thoroughly adapted to the clientele is also presented. Online guides addressing information literacy topics complement the programme. Results and evaluation: A small team of librarians and technicians taught 276 hours of library instruction during the 2011-2012 academic year. Methods used for evaluating information skills include scoring features of literature searches and user satisfaction surveys. Discussion: Privileged contacts between librarians and faculty resulting from embedded library instruction as well as from active participation in library committees result in a growing reputation of library services across academic departments and bring forth collaboration opportunities. Sustainability and evolution of the library instruction programme is warranted by frequent communication with partners in the clinical field, active involvement in academic networks and health library associations, and reflective professional strategies.

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This thesis provides three original contributions to the field of Decision Sciences. The first contribution explores the field of heuristics and biases. New variations of the Cognitive Reflection Test (CRT--a test to measure "the ability or disposition to resist reporting the response that first comes to mind"), are provided. The original CRT (S. Frederick [2005] Journal of Economic Perspectives, v. 19:4, pp.24-42) has items in which the response is immediate--and erroneous. It is shown that by merely varying the numerical parameters of the problems, large deviations in response are found. Not only the final results are affected by the proposed variations, but so is processing fluency. It seems that numbers' magnitudes serve as a cue to activate system-2 type reasoning. The second contribution explores Managerial Algorithmics Theory (M. Moldoveanu [2009] Strategic Management Journal, v. 30, pp. 737-763); an ambitious research program that states that managers display cognitive choices with a "preference towards solving problems of low computational complexity". An empirical test of this hypothesis is conducted, with results showing that this premise is not supported. A number of problems are designed with the intent of testing the predictions from managerial algorithmics against the predictions of cognitive psychology. The results demonstrate (once again) that framing effects profoundly affect choice, and (an original insight) that managers are unable to distinguish computational complexity problem classes. The third contribution explores a new approach to a computationally complex problem in marketing: the shelf space allocation problem (M-H Yang [2001] European Journal of Operational Research, v. 131, pp.107--118). A new representation for a genetic algorithm is developed, and computational experiments demonstrate its feasibility as a practical solution method. These studies lie at the interface of psychology and economics (with bounded rationality and the heuristics and biases programme), psychology, strategy, and computational complexity, and heuristics for computationally hard problems in management science.