859 resultados para Ask a librarian
Resumo:
This paper considers the problem of language change. Linguists must explain not only how languages are learned but also how and why they have evolved along certain trajectories and not others. While the language learning problem has focused on the behavior of individuals and how they acquire a particular grammar from a class of grammars ${cal G}$, here we consider a population of such learners and investigate the emergent, global population characteristics of linguistic communities over several generations. We argue that language change follows logically from specific assumptions about grammatical theories and learning paradigms. In particular, we are able to transform parameterized theories and memoryless acquisition algorithms into grammatical dynamical systems, whose evolution depicts a population's evolving linguistic composition. We investigate the linguistic and computational consequences of this model, showing that the formalization allows one to ask questions about diachronic that one otherwise could not ask, such as the effect of varying initial conditions on the resulting diachronic trajectories. From a more programmatic perspective, we give an example of how the dynamical system model for language change can serve as a way to distinguish among alternative grammatical theories, introducing a formal diachronic adequacy criterion for linguistic theories.
Resumo:
This paper presents an adaptive learning model for market-making under the reinforcement learning framework. Reinforcement learning is a learning technique in which agents aim to maximize the long-term accumulated rewards. No knowledge of the market environment, such as the order arrival or price process, is assumed. Instead, the agent learns from real-time market experience and develops explicit market-making strategies, achieving multiple objectives including the maximizing of profits and minimization of the bid-ask spread. The simulation results show initial success in bringing learning techniques to building market-making algorithms.
Resumo:
The statistical analysis of compositional data should be treated using logratios of parts, which are difficult to use correctly in standard statistical packages. For this reason a freeware package, named CoDaPack was created. This software implements most of the basic statistical methods suitable for compositional data. In this paper we describe the new version of the package that now is called CoDaPack3D. It is developed in Visual Basic for applications (associated with Excel©), Visual Basic and Open GL, and it is oriented towards users with a minimum knowledge of computers with the aim at being simple and easy to use. This new version includes new graphical output in 2D and 3D. These outputs could be zoomed and, in 3D, rotated. Also a customization menu is included and outputs could be saved in jpeg format. Also this new version includes an interactive help and all dialog windows have been improved in order to facilitate its use. To use CoDaPack one has to access Excel© and introduce the data in a standard spreadsheet. These should be organized as a matrix where Excel© rows correspond to the observations and columns to the parts. The user executes macros that return numerical or graphical results. There are two kinds of numerical results: new variables and descriptive statistics, and both appear on the same sheet. Graphical output appears in independent windows. In the present version there are 8 menus, with a total of 38 submenus which, after some dialogue, directly call the corresponding macro. The dialogues ask the user to input variables and further parameters needed, as well as where to put these results. The web site http://ima.udg.es/CoDaPack contains this freeware package and only Microsoft Excel© under Microsoft Windows© is required to run the software. Kew words: Compositional data Analysis, Software
Resumo:
Theory of compositional data analysis is often focused on the composition only. However in practical applications we often treat a composition together with covariables with some other scale. This contribution systematically gathers and develop statistical tools for this situation. For instance, for the graphical display of the dependence of a composition with a categorical variable, a colored set of ternary diagrams might be a good idea for a first look at the data, but it will fast hide important aspects if the composition has many parts, or it takes extreme values. On the other hand colored scatterplots of ilr components could not be very instructive for the analyst, if the conventional, black-box ilr is used. Thinking on terms of the Euclidean structure of the simplex, we suggest to set up appropriate projections, which on one side show the compositional geometry and on the other side are still comprehensible by a non-expert analyst, readable for all locations and scales of the data. This is e.g. done by defining special balance displays with carefully- selected axes. Following this idea, we need to systematically ask how to display, explore, describe, and test the relation to complementary or explanatory data of categorical, real, ratio or again compositional scales. This contribution shows that it is sufficient to use some basic concepts and very few advanced tools from multivariate statistics (principal covariances, multivariate linear models, trellis or parallel plots, etc.) to build appropriate procedures for all these combinations of scales. This has some fundamental implications in their software implementation, and how might they be taught to analysts not already experts in multivariate analysis
Resumo:
Autonomous underwater vehicles (AUV) represent a challenging control problem with complex, noisy, dynamics. Nowadays, not only the continuous scientific advances in underwater robotics but the increasing number of subsea missions and its complexity ask for an automatization of submarine processes. This paper proposes a high-level control system for solving the action selection problem of an autonomous robot. The system is characterized by the use of reinforcement learning direct policy search methods (RLDPS) for learning the internal state/action mapping of some behaviors. We demonstrate its feasibility with simulated experiments using the model of our underwater robot URIS in a target following task
Resumo:
El análisis micropolítico de los Discursos Bibliotecarios (DB) desinviste a las maquinas codificadoras de las misiones, que la institución bibliotecaria reproduce como valor agregado ligado a un modo de ser con base territorial; desmonta las máquinas axiomáticas de los manifiestos bibliotecarios que producen un valor agregado incluyendo forzadamente como deudores de conocimiento a los que no dominan el saber acumulado; y revela el valor agregado del capitalismo mundial integrado (CMI) que instaura procedimientos tácticos cada vez mas autoreferenciales (normas, pautas y directrices). En oposición a esos dispositivos de alineación, culpabilización, responsabilización y control, proponemos un proceso de singularización bibliotecaria en función de la producción de información ambiental en una Biblioteca Escolar Ecológica en conexión con redes sociales y bases de datos documentales.
Resumo:
Esta tesis producto del trabajo de investigación se planteo sobre las bases de un derecho administrativo interno creado para resolver los problemas suscitados al interior del Estado en consonancia con los postulados constitucionales, teniendo en cuenta el artículo 4° en que se establece la supremacía de la Constitución y los artículo 9°, 93, 94 y 224 al 227 que ordenan el desarrollo del derecho de integración en el marco de los países Latinoamericanos y del Caribe, por lo que surge la imperiosa necesidad de armonizar el derecho de la integración con el ordenamiento jurídico nacional y en especial con el derecho administrativo quien deberá recepcionar el mencionado ordenamiento supraestatal, alterando las tradicionales concepciones de las fuentes de este derecho interno. Por lo tanto, desde la perspectiva del derecho administrativo comprendido como un derecho legislado que regula las relaciones entre el Estado y los particulares en el que prevalece el “principio de legalidad” de los actos administrativos, se puede intuir que constituye un problema jurídico los impactos derivados de los tratados de integración, donde nos preguntamos sí las categorías de fuentes actuales del derecho administrativo son las adecuadas para abordar la recepción de estas disposiciones Por lo que al explorara las incidencias en el derecho administrativo con ocasión de la recepción del derecho de integración con particular énfasis en la Comunidad Andina, identificamos que uno de los rasgos más distintivos del ordenamiento jurídico andino, como el de otros esquemas de integración, proviene del discutido concepto de supranacionalidad. Dentro de la teoría jurídica contemporánea la comprensión de este término trae una novísima concepción que al mismo tiempo es respetuosa de la soberanía interna de los Estados miembros, la cual permite el surgimiento del nuevo ente común donde es posible la distribución de competencias en la reglamentación de ciertos ámbitos entre autoridades multilaterales y nacionales, conservando su propia autonomía. Este concepto ha permitido que en el ordenamiento comunitario andino, a semejanza de lo que acontece en el derecho interno de los Estados, exista un sistema de control de las normas jurídicas garantizado por una jurisdicción contenciosa-administrativa ejercida a través del Tribunal de Justicia de la Comunidad Andina. Lo que en definitiva incide en el derecho administrativo interno al encontramos frente a ordenamientos independientes, como lo son los del derecho de integración, en los que se producen, aplican y ejecutan normas según las reglas de juego adoptadas para ese efecto por los Estados miembros, que dependerán del marco del proceso de integración y su armonización con las normas internas. Es por ello, que en el resultado final de esta tesis se constata la aparición de nuevas fuentes de legalidad, donde ya no sólo se contemplará la ley y la jurisprudencia, ésta última posicionada con el devenir del tiempo debido a su pertinencia, como lo podemos contrastar con la expedición del Nuevo Código de Procedimiento Contencioso Administrativo (L. 1437/11) que aún no ha entrado en vigencia, en donde se resalta la importancia del Precedente Judicial a partir de las sentencias de unificación del Consejo de Estado. Pero más allá, de este nuevo reconocimiento legislativo, el sistema de fuentes establecido se verá alterado en su jerarquía con el derecho que nace con ocasión de los tratados de integración, lo que aún no se refleja en este nuevo Código, el cual no prevé la aplicación de las nuevas fuentes de legalidad.
Resumo:
These slides support students in understanding how to respond to the challenge of: "I’ve been told not to use Google or Wikipedia to research my essay. What else is there?" The powerpoint guides students in how to identify high quality, up to date and relevant resources on the web that they can reliably draw upon for their academic assignments. The slides were created by the subject liaison librarian who supports the School of Electronics and Computer Science at the UNiversity of Southampton, Fiona Nichols.
Resumo:
Powerpoint presentation of the talk given by Fiona Nichols, ECS Academic Liaison Librarian on Thursday 25th November for Info 2009.
Resumo:
These slides support students in understanding how to respond to the challenge of: "I’ve been told not to use Google or Wikipedia to research my essay. What else is there?" The powerpoint guides students in how to identify high quality, up to date and relevant resources on the web that they can reliably draw upon for their academic assignments. The slides were created by the subject liaison librarian who supports the School of Electronics and Computer Science at the University of Southampton, Fiona Nichols.
Resumo:
Like any form of human interaction and communication it is possible to view Social Media as a means for the powerful to influence and control the less powerful. But what is power on social media, how might we measure or affect it, and does it translate to the real world? In this lecture we will look at the philosophical definitions of power, and explore how it has been analysed in social networks and social media systems. We will also look at the characteristics of social networks that impact on power, including Homophily, Heterophily, CyberBalkanization and Thresholds of Collective Action. Finally we will ask what evidence there is that power in social media can affect what goes on in the real world, and explore some real and fictional examples of protest to see what the consequences of social media actually are on sometimes violent political debate.
Resumo:
Building software for Web 2.0 and the Social Media world is non-trivial. It requires understanding how to create infrastructure that will survive at Web scale, meaning that it may have to deal with tens of millions of individual items of data, and cope with hits from hundreds of thousands of users every minute. It also requires you to build tools that will be part of a much larger ecosystem of software and application families. In this lecture we will look at how traditional relational database systems have tried to cope with the scale of Web 2.0, and explore the NoSQL movement that seeks to simplify data-storage and create ultra-swift data systems at the expense of immediate consistency. We will also look at the range of APIs, libraries and interoperability standards that are trying to make sense of the Social Media world, and ask what trends we might be seeing emerge.
Resumo:
Technology is changing how students learn and how we research. Perhaps you want to use technology to enhance communication or improve student support. You may want create a distance learning activity, a flexibly delivered module or indeed a whole course. You may simply want to find out where to find authoritative information, or to see what support exists for this type of work. The University is committed to delivering high quality learning and teaching, using technology where appropriate, in order to offer a distinctive Southampton educational experience. Technology Enhanced Learning (TEL), also known as e‑learning, is becoming increasingly important to students, teaching staff and the institution. This guide highlights some of the most important matters to consider. It is intended to help you to tackle the key issues that determine the success of TEL projects and to work on those projects in a considered way. Written with the input of colleagues from around the University, it prompts you to ask important questions and points you to sources of up-to-date knowledge and advice. Technology changes rapidly. This guide is about managing the work in a practical way. The University supports the use of a variety of TEL approaches for teaching and learning and colleagues are ready to offer their experience and advice. Each person has distinctive skills and specific experiences. No single person will have all the answers you are looking for. Be ready to investigate alternative approaches that suit you and your students’ needs in different ways. - Madeline Paterson, University of Southampton
Resumo:
El cáncer de cuello uterino y su mortalidad en Colombia ha permanecido constantes pese a los esfuerzos institucionales, distritales y nacionales que han buscado fortalecer los programas de prevención; sin embargo las estrategias actuales hacen énfasis en la toma de citología y no en la solicitud oportuna del resultado y el tratamiento de la usuaria en caso de anormalidad. METODOLOGIA: Se realizó un estudio en dos fases, un análisis descriptivo se analizaron 12875 y una segunda que involucro 257 pacientes en un análisis de casos y controles de una muestra aleatoria. RESULTADOS: Se utiliza para análisis bivariado la prueba de Chi cuadrado y regresión logística que muestran diferencias significativas en los siguientes variables: la explicación sobre la importancia del examen (p= 0.0060), importancia de la solicitud de resultado (p= 0.003), explicación sobre cuando reclamarlo (p=0.030), distancia entre residencia y centro de salud (p=0.065) DISCUSIÓN: En nuestro estudio se identificó que los factores como el acceso de la paciente al centro de salud, el tiempo del cual dispone para solicitar el resultado, si el dinero con el que cuenta la paciente para desplazarse al hospital, si es la primera vez que se realiza la citología, si le explicaron la importancia de reclamar el resultado y en que lapso de tiempo debía hacerlo, la información que tiene acerca de la importancia de realizarse la citología contribuyen en el hecho de que una paciente de esta población de un hospital público reclame o no su resultado de su citología
Resumo:
Revisión del problema de la filosofía de la Inteligencia Artificial a la vista del Equilibrio refractivo. La revisión del problema se lleva a cabo para mostrar como "¿pueden pensar las máquinas?" sólo se ha evaluado en los terminos humanos. El equilibrio refractivo se plantea como una herramienta para definir conceptos de tal modo que la experiencia y los preceptos se encuentren en equilibrio, para con él construir una definición de pensar que no esté limitada exclusivamente a "pensar tal y como lo hacen los humanos".