La mecánica newtoniana en bachillerato. Diseño de problemas y evaluación de aprendizajes

Se presenta una investigación realizada en el campo de la Mecánica con alumnos de 1º Bachillerato trabajando con un modelo investigativo de resolución de problemas. Resolver las situaciones problemáticas diseñadas al efecto ha permitido comprobar la potencialidad del modelo para vencer la resistencia de las concepciones alternativas de los estudiantes en estos niveles educativos. Se presentan los resultados obtenidos en relación al cambio conceptual y al aprendizaje de los procedimientos científicos implicados. La incidencia positiva en las actitudes constata la importancia de utilizar este tipo de metodologías que proporcionan a los alumnos herramientas útiles y contribuyen a la adquisición de una competencia básica: “aprender a aprender”, un objetivo relevante en sí mismo y un poderoso medio para conseguir alcanzar los demás objetivos educativos

La mecánica newtoniana en bachillerato. Diseño de problemas y evaluación de aprendizajes

Se presenta una investigación realizada en el campo de la Mecánica con alumnos de 1º Bachillerato trabajando con un modelo investigativo de resolución de problemas. Resolver las situaciones problemáticas diseñadas al efecto ha permitido comprobar la potencialidad del modelo para vencer la resistencia de las concepciones alternativas de los estudiantes en estos niveles educativos. Se presentan los resultados obtenidos en relación al cambio conceptual y al aprendizaje de los procedimientos científicos implicados. La incidencia positiva en las actitudes constata la importancia de utilizar este tipo de metodologías que proporcionan a los alumnos herramientas útiles y contribuyen a la adquisición de una competencia básica: "aprender a aprender", un objetivo relevante en sí mismo y un poderoso medio para conseguir alcanzar los demás objetivos educativos

Clustering of Russian texts using χ² statistics

Проблема обнаружения скрытых структур текста связана с перспективной методикой установления авторства. В работе описан Корпус текстов русского языка, созданный для исследований текстов методами математической статистики. Описывается исследование, проведённое на базе Корпуса с применением статистики χ2. Кластеризация текстов, обнаруженная в результате исследования, может служить основанием для их атрибуции. Работа выполнена на кафедре полиграфии и веб-дизайна ИРИТ-РтФ УрФУ.The problem of detection of the hidden structures of the text is associated with a promising method of attribution. The paper describes a corpus of Russian language created for investigations of texts by the methods of mathematical statistics. The research conducted on the basis of the statistics χ2 is described. Clustering of texts discovered by the study can serve as a basis for their attribution. The work was coudveted at the department of printing art and web-design, Ural Federal University

Основные методики исследования структуры текста

Проблема обнаружения скрытых структур текста связана с перспективной методикой установления авторства. В работе обосновывается выбор методики для обнаружения и изучения таких структур в русскоязычных текстах. Рассмотрены основные методики, оперирующие в качестве единиц анализа смыслосодержащими элементами, лексическими или графическими формами и частотными характеристиками текста. Авторы предполагают существование скрытых структур, исходя из ранее полученных результатов. Предлагается использование частотного анализа как наиболее адекватного задаче обнаружения скрытых структур текста.The problem of finding the hidden structures of the test is associated with promising method of attribution. The paper substantiates the choice of methods for the detection and study of such structures in the Russian-language texts. The basic techniques that operate as units of analysis elements that carry meaning, lexical or graphical form, and frequency characteristics of the text. The authors suggest the existence of hidden structures, based on previous results. It is proposed to use frequency analysis as the most adequate to detect hidden structures of the text

Attribution is a Russian-language texts using the law of large numbers

Работа посвящена статистическому исследованию русскоязычных текстов. Исследуется связь между длиной текста и среднеквадратичным отклонением величины χ2 для распределения сочетаний гласных букв. Установлена справедливость закона больших чисел для этой величины. Работа выполнена на кафедре полиграфии и веб-дизайна ИРИТ-РтФ УрФУ.The work is devoted to the statistical study of Russian texts. Examines the relationship between text length and standard deviation of the χ2 values for the distribution of combinations of vowels. Established the validity of the law of large numbers for this value. The work was performed at the Department of printing and web design IRIT-RTF UrFU

Machine attribution of Russian-language texts: a review of methods

The paper considers the problem of attribution and classification of Russian language texts. There are characteristics of different approaches. Authors explain choice of approaches and propose parameters for classificationВ статье рассматривается проблема атрибуции и классификации русскоязычных текстов. Приводятся характеристики различных подходов и обосновывается выбор. В рамках каждого подхода предлагается параметр для классификаци

Tools of case linguistics

В статье рассмотрено несколько корпусов русского языка. Описаны цели, с которыми такие корпуса создавались, как они устроены и то, какие результаты у них есть на сегодняшний день.In article some cases of Russian are considered. The purposes with which such cases were created are described as they are arranged also what results they have today

Application of the random walk model for description Russian-language texts

В статье рассматривается проблема анализа и атрибуции текста с помощью модели случайных блужданий. В качестве элемента атрибуции предлагается коэффициент пропорциональности в законе Эйнштейна, условно названный коэффициентом диффузии. В ходе работы было сделано предположение, что коэффициент диффузии связан с формой коммуникации между автором и читателем.The paper considers the problem of analysis is and attribution of text using the random walk model. One of elements is coefficient of proportionality in Einstein law, which is named conventionally diffusion coefficient. We suppose that diffusion coefficient is associated with form of communication between author and reader

Usefulness of data from magnetic resonance imaging to improve prediction of dementia: population based cohort study

© BMJ Publishing Group Ltd 2015. OBJECTIVE: To determine whether the addition of data derived from magnetic resonance imaging (MRI) of the brain to a model incorporating conventional risk variables improves prediction of dementia over 10 years of follow-up. DESIGN: Population based cohort study of individuals aged ≥65. SETTING: The Dijon magnetic resonance imaging study cohort from the Three-City Study, France. PARTICIPANTS: 1721 people without dementia who underwent an MRI scan at baseline and with known dementia status over 10 years' follow-up. MAIN OUTCOME MEASURE: Incident dementia (all cause and Alzheimer's disease). RESULTS: During 10 years of follow-up, there were 119 confirmed cases of dementia, 84 of which were Alzheimer's disease. The conventional risk model incorporated age, sex, education, cognition, physical function, lifestyle (smoking, alcohol use), health (cardiovascular disease, diabetes, systolic blood pressure), and the apolipoprotein genotype (C statistic for discrimination performance was 0.77, 95% confidence interval 0.71 to 0.82). No significant differences were observed in the discrimination performance of the conventional risk model compared with models incorporating data from MRI including white matter lesion volume (C statistic 0.77, 95% confidence interval 0.72 to 0.82; P=0.48 for difference of C statistics), brain volume (0.77, 0.72 to 0.82; P=0.60), hippocampal volume (0.79, 0.74 to 0.84; P=0.07), or all three variables combined (0.79, 0.75 to 0.84; P=0.05). Inclusion of hippocampal volume or all three MRI variables combined in the conventional model did, however, lead to significant improvement in reclassification measured by using the integrated discrimination improvement index (P=0.03 and P=0.04) and showed increased net benefit in decision curve analysis. Similar results were observed when the outcome was restricted to Alzheimer's disease. CONCLUSIONS: Data from MRI do not significantly improve discrimination performance in prediction of all cause dementia beyond a model incorporating demographic, cognitive, health, lifestyle, physical function, and genetic data. There were, however, statistical improvements in reclassification, prognostic separation, and some evidence of clinical utility

PLoS One

Diffusion MRI is extensively used to investigate changes in white matter microstructure. However, diffusion measures within white matter tissue can be affected by partial volume effects due to cerebrospinal fluid and white matter hyperintensities, especially in the aging brain. In previous aging studies, the cingulum bundle that plays a central role in the architecture of the brain networks supporting cognitive functions has been associated with cognitive deficits. However, most of these studies did not consider the partial volume effects on diffusion measures. The aim of this study was to evaluate the effect of free water elimination on diffusion measures of the cingulum in a group of 68 healthy elderly individuals. We first determined the effect of free water elimination on conventional DTI measures and then examined the effect of free water elimination on verbal fluency performance over 12 years. The cingulum bundle was reconstructed with a tractography pipeline including a white matter hyperintensities mask to limit the negative impact of hyperintensities on fiber tracking algorithms. We observed that free water elimination increased the ability of conventional DTI measures to detect associations between tissue diffusion measures of the cingulum and changes in verbal fluency in older individuals. Moreover, free water content and mean diffusivity measured along the cingulum were independently associated with changes in verbal fluency. This suggests that both tissue modifications and an increase in interstitial isotropic water would contribute to cognitive decline. These observations reinforce the importance of using free water elimination when studying brain aging and indicate that free water itself could be a relevant marker for age-related cingulum white matter modifications and cognitive decline