69 research outputs found

    Lines of Descent: Kuhn and Beyond

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    yesThomas S. Kuhn is famous both for his work on the Copernican Revolution and his ‘paradigm’ view of scientific revolutions. But Kuhn later abandoned the notion of paradigm (and related notions) in favour of a more ‘evolutionary’ view of the history of science. Kuhn’s position therefore moved closer to ‘continuity’ models of scientific progress, for instance ‘chain-of-reasoning’ models, originally championed by D. Shapere. The purpose of this paper is to contribute to the debate around Kuhn’s new ‘developmental’ view and to evaluate these competing models with reference to some major innovations in the history of cosmology, from Copernicanism to modern cosmology. This evaluation is made possible through some unexpected overlap between Kuhn’s earlier discontinuity model and various versions of the later continuity models. It is the thesis of this paper that the ‘chain-of-reasoning’ model accounts better for the cosmological evidence than both Kuhn’s early paradigm model and his later developmental view of the history of science

    Technoscientia est Potentia?: Contemplative, interventionist, constructionist and creationist idea(l)s in (techno)science

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    Within the realm of nano-, bio-, info- and cogno- (or NBIC) technosciences, the ‘power to change the world’ is often invoked. One could dismiss such formulations as ‘purely rhetorical’, interpret them as rhetorical and self-fulfilling or view them as an adequate depiction of one of the fundamental characteristics of technoscience. In the latter case, a very specific nexus between science and technology, or, the epistemic and the constructionist realm is envisioned. The following paper focuses on this nexus drawing on theoretical conceptions as well as empirical material. It presents an overview of different technoscientific ways to ‘change the world’—via contemplation and representation, intervention and control, engineering, construction and creation. It further argues that the hybrid character of technoscience makes it difficult (if not impossible) to separate knowledge production from real world interventions and challenges current science and technology policy approaches in fundamental ways

    Desarrollo de un componente de analítica para la clasificación de textos cortos dirigido a un proyecto institucional e integrable en una plataforma Web

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    Auxiliar de InvestigaciónLa clasificación de texto es una de las áreas de estudio de la disciplina del aprendizaje de máquina (en inglés Machine Learning) en donde se busca, posterior a una etapa de entrenamiento, predecir una categoría para datos de entrada que no hayan sido clasificados previamente. La longitud de los textos cortos, puede conllevar a una pérdida en la precisión de los resultados entregados por el proceso de clasificación de texto, ya que la cantidad de características aprovechables disminuye. Por lo tanto, se busca explorar una solución que permita realizar tareas de clasificación de textos cortos, con un nivel de precisión cercano al 80 %. Se desarrolló un componente de clasificación de textos cortos en el lenguaje de programación Python, haciendo uso del framework Flask el cual permite peticiones a través de un API y realiza la clasificación datasets que cumplan con el formato de entrada. Se probaron los resultados de este trabajo mediante el uso de publicaciones extraídas desde cuentas de Twitter, debido a la restricción sobre la longitud de sus publicaciones. La clasificación se realizó mediante el uso de algoritmos de aprendizaje supervisado, y en el mejor de los casos, la precisión obtenida fue cercana al 85 %.1. INTRODUCCIÓN 2. MARCO DE REFERENCIA 3. METODOLOGÍA 4. ESTADO DEL ARTE 5. DESARROLLO 6. RESULTADOS 7. CONCLUSIONES 8. TRABAJO FUTURO BIBLIOGRAFÍA ANEXOSPregradoIngeniero de Sistema

    Retrieval of aerosol optical thickness for desert conditions using MERIS observations during the SAMUM campaign

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    This journal is published under the terms of the Creative Commons Attribution-Noncommercial 3.0 Unported LicenseApproximately 30% of the land surface is arid, having desert or semi-desert conditions. Aerosol originating from these regions plays a significant role in climate and atmospheric chemistry of the atmosphere. Retrieving aerosol properties from space-borne platforms above desert conditions, where the surface reflectance is usually very bright, is a challenging task. The proportion of the surface to top of atmosphere (TOA) reflectance can reach values over 90%, especially for wavelength above 500 nm. For these reasons detailed knowledge of aerosol and surface optical properties from these regions is required to separate atmosphere from intrinsically bright surfaces. An approach to retrieve aerosol properties over arid and semi-arid regions based on the Bremen Aerosol Retrieval (BAER) has been developed and validated within the Dust Aerosol Retrievals from Space-Born Instruments (DREAMS) Project, which is part of the Saharan Mineral Dust Experiment (SAMUM, 2006). Combining measurements of the backscattered radiation from the Medium Resolution Imaging Spectrometer (MERIS) instrument aboard Environmental Satellite (ENVISAT) and ground-based measurements in Morocco in radiation closure experiments yields the aerosol optical properties of mineral dust at selected locations.Peer reviewe

    Measurements of desert dust optical characteristics at Porte au Sahara during SAMUM

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    This journal is published under the terms of the Creative Commons Attribution-Noncommercial 3.0 Unported LicenseMain optical characteristics of desert dust, such as phase function and single scattering albedo, have been derived from combinations of sun-/sky-radiometer and satellite measurements during the SAMUM experiment (10 May-10 June 2006) at the site Porte au Sahara (30.237 degrees N, 5.607 degrees W) in South Morocco. Scattering phase functions have been retrieved using combined data of spectral aerosol optical thickness (AOT) and spectral sky brightness in the almucantar, considering non-spherical light scattering. Intercomparisons of modelled top-of-atmosphere (TOA) reflectance with satellite observations of the Medium Resolution Imaging Spectrometer (MERIS) and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography () instrument have been used for the estimation of spectral single scattering albedo. For the radiative transfer calculations scattering phase functions and AOT from ground-based observations have been used. The spectral single scattering albedo ranges from 0.93 in the blue to 0.98 at 753 nm.Peer reviewe
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