Simpson's Paradox, Lord's Paradox, and Suppression Effects are the same phenomenon – the reversal paradox

This article discusses three statistical paradoxes that pervade epidemiological research: Simpson's paradox, Lord's paradox, and suppression. These paradoxes have important implications for the interpretation of evidence from observational studies. This article uses hypothetical scenarios to illustrate how the three paradoxes are different manifestations of one phenomenon – the reversal paradox – depending on whether the outcome and explanatory variables are categorical, continuous or a combination of both; this renders the issues and remedies for any one to be similar for all three. Although the three statistical paradoxes occur in different types of variables, they share the same characteristic: the association between two variables can be reversed, diminished, or enhanced when another variable is statistically controlled for. Understanding the concepts and theory behind these paradoxes provides insights into some controversial or contradictory research findings. These paradoxes show that prior knowledge and underlying causal theory play an important role in the statistical modelling of epidemiological data, where incorrect use of statistical models might produce consistent, replicable, yet erroneous results

School integration and the friendships of youth with developmental disabilities

- The present study was an investigation into the effect ofschool integration on the friendships ofyouth with developmental disabilities and their peers without disabilities. The youths, their parents, and their teachers provided insights into the youths' friendships. A qualitative paradigm was used in this research. The researcher guided the collection and analysis ofthe data with the phenomenologicallifeworld existentials of body, space, time, and human relation (Van Manen, 1990). Individual interviews were conducted with each youth, and group interviews were conducted with each triad (a youth, their parent(s), and their teacher) to discuss the youth's friendships and the supports necessary to facilitate the friendships. Through phenomenological analysis of the data, four thematic statements emerged: friendships are far from perfect, to have a friend you have to be a friend, parents as choreographers offriendship, and teachers as reluctant partners in friendship facilitation. Based on the results ofthis study, it was concluded that the development of friendships between youth with developmental disabilities and their peers without disabilities was happening in integrated school settings. However, it was also evident that the support ofteachers and parents alike were required to facilitate the development and maintenance ofsuch friendships. Recommendations for practice are discussed, including the need for active participation by the youth's parents in the facilitation offriendships, and the use ofa "circle offriends" to facilitate friendship development. Also discussed are the recommendations for further research, including the need for the youth's friends to be interviewed regarding their friendships with the youth with disabilities, and the need for researcher observation ofth~ friendships in action. Further research could also explore the role ofthe mother versus the father in facilitating friendships, and the role of recreation and leisure opportunities in the ,development offriendships

Improving Recall of Browsing Sets in Image Retrieval from a Semiotics Perspective

The purpose of dissertation is to utilize connotative messages for enhancing image retrieval and browsing. By adopting semiotics as a theoretical tool, this study explores problems of image retrieval and proposes an image retrieval model. The semiotics approach conceptually demonstrates that: 1) a fundamental reason for the dissonance between retrieved images and user needs is representation of connotative messages, and 2) the image retrieval model which makes use of denotative index terms is able to facilitate users to browse connotatively related images effectively even when the users' needs are potentially expressed in the form of denotative query. Two experiments are performed for verifying the semiotic-based image retrieval model and evaluating the effectiveness of the model. As data sources, 5,199 records are collected from Artefacts Canada: Humanities by Canadian Heritage Information Network, and the candidate terms of connotation and denotation are extracted from Art & Architecture Thesaurus. The first experiment, by applying term association measures, verifies that the connotative messages of an image can be derived from denotative messages of the image. The second experiment reveals that the association thesaurus which is constructed based on the associations between connotation and denotation facilitates assigning connotative terms to image documents. In addition, the result of relevant judgments presents that the association thesaurus improves the relative recall of retrieved image documents as well as the relative recall of browsing sets. This study concludes that the association thesaurus indicating associations between connotation and denotation is able to improve the accessibility of the connotative messages. The results of the study are hoped to contribute to the conceptual knowledge of image retrieval by providing understandings of connotative messages within an image and to the practical design of image retrieval system by proposing an association thesaurus which can supplement the limitations of the current content-based image retrieval systems (CBIR)

A model for stylometric analysis of e-mails for recipient-based personalised writing

Trabajo de Fin de Grado en Doble Grado en Ingeniería Informática y Matemáticas, Facultad de Informática UCM, Departamento de Ingeniería del Software e Inteligencia Artificial, Curso 2019/2020Hoy en día se envían más de 306 mil millones de correos electrónicos diarios tanto en el ámbito profesional como el personal. Sin embargo, a pesar de que el canal sea el mismo, nuestro estilo varía en función del destinatario del mensaje. La estilometría en correos electrónicos es un campo de estudio reciente que trata de parametrizar el estilo de escritura a través de métricas. La mayoría de las investigaciones en este campo se centran en la detección de spam o identificación y autenticación de la autoría de los mensajes. En este trabajo se plantea un nuevo enfoque: estudiar el estilo dependiendo del destinatario del correo electrónico. El avance en esta dirección permitiría personalizar los sistemas de redacción de correos electrónicos de manera que fueran capaces de generar mensajes distintos en función del destinatario. En este trabajo se desarrolla una herramienta de análisis estilométrico de correos electrónicos, para el servicio de Gmail, que permite extraer y calcular distintas métricas de los mensajes de un usuario. Dicho analizador de estilo cuenta con cuatro módulos (extracción, preprocesamiento, corrección tipográfica y medición de estilo) que abordan las distintas fases necesarias para obtener los descriptores de estilo de cada uno de los mensajes. Una vez se cuenta con los resultados al evaluar las distintas métricas sobre cada mensaje, se analizan. Para ello se hace uso de populares técnicas de aprendizaje automático como K-Medias, Análisis de Componentes Principales y Árboles de Decisión. El objetivo es extraer conclusiones que permitan proponer un modelo de análisis estilométrico de correos electrónicos para la redacción personalizada basada en el destinatario. En este análisis de datos se encuentran ocho métricas que distinguen mejor el estilo en función del receptor de la información. Por último, se presenta el diseño de un sistema que utiliza estas ocho métricas para redactar correos electrónicos distintos según el destinatario. Este modelo puede ser de utilidad para personalizar aquellos sistemas de generación de lenguaje natural en función del destinatario, o de la audiencia a la que va dirigida el texto.Nowadays, more than 306 billion e-mails are sent daily, both in the professional and personal scopes. However, despite the fact that the channel is the same, our style varies depending on the recipient of the message. Stylometry in e-mails is a recent field of study that tries to obtain the definition of writing style through metrics. Nevertheless, most research in this field focuses on spam detection or message author identification and authentication. In this work a new approach is proposed: to study the style depending on the recipient of the e-mail. Moving in this direction would allow us to personalise e-mail writing systems so that they are capable of generating different messages depending on the recipient. In this work we develop a tool for the stylometric analysis of e-mails, for the Gmail service, which allows us to extract and calculate different metrics from the messages of a user. This style analyser has four modules (extraction, preprocessing, typographic correction and style measuring) that deal with the different phases needed to obtain the style descriptors of each of the messages. Once we have the results of evaluating the different metrics on each message, we analyse them. To this end, we use popular machine learning techniques such as K-Means, Principal Component Analysis and Decision Trees. The objective is to draw conclusions that allow us to propose a model of stylometric analysis of e-mails for personalized writing based on the recipient. In this data analysis we find eight metrics that better distinguish style according to the receiver of the information. Finally, we present the design of a system that uses these eight metrics to write different e-mails according to the recipient. This model can be useful to personalise those natural language generation systems depending on the recipient, or on the audience to which the text is addressed.Depto. de Ingeniería de Software e Inteligencia Artificial (ISIA)Fac. de InformáticaTRUEunpu

Trajectory prediction of moving objects by means of neural networks

Thesis (Master)--Izmir Institute of Technology, Computer Engineering, Izmir, 1997Includes bibliographical references (leaves: 103-105)Text in English; Abstract: Turkish and Englishviii, 105 leavesEstimating the three-dimensional motion of an object from a sequence of object positions and orientation is of significant importance in variety of applications in control and robotics. For instance, autonomous navigation, manipulation, servo, tracking, planning and surveillance needs prediction of motion parameters. Although "motion estimation" is an old problem (the formulations date back to the beginning of the century), only recently scientists have provided with the tools from nonlinear system estimation theory to solve this problem eural Networks are the ones which have recently been used in many nonlinear dynamic system parameter estimation context. The approximating ability of the neural network is used to identifY the relation between system variables and parameters of a dynamic system. The position, velocity and acceleration of the object are estimated by several neural networks using the II most recent measurements of the object coordinates as input to the system Several neural network topologies with different configurations are introduced and utilized in the solution of the problem. Training schemes for each configuration are given in detail. Simulation results for prediction of motion having different characteristics via different architectures with alternative configurations are presented comparatively

Policy Networks: Empirical Evidence and Theoretical Considerations

Political governance in modern societies can no longer be conceived in terms of external government control of society but emerges from a plurality of governing agents. In contemporary policy making, governmental and non-governmental actors are interconnected in complex networks of interaction, exchanging information and other resources. This reader presents the results of empirical network studies in a variety of policy sectors and in different countries. It also provides insights into innovative quantitative and qualitative approaches to network analysis.Part One • Theoretical Considerations 1 Introduction: Studying Policy Networks Bernd Marin and Renate Mayntz 2 Policy Networks and Policy Analysis: Scrutinizing a New Analytical Toolbox Patrick Kenis and Volker Schneider Part Two • Policy Networks in National Policy Domains 3 Organizations in Political Action: Representing Interests in National Policy Making Edward O. Laumann and John P. Heinz with Robert Nelson and Robert Salisbury 4 Policy Networks in the German Telecommunications Domain Volker Schneider and Raymund Werle 5 Policy Networks and Change: The Case of High-Tc Superconductors Dorothea Jansen Part Three • Cross-National Variations in Policy Networks 6 Political Exchange in the German and American Labor Policy Domain Franz Urban Pappi and David Knoke 7 Fencing Off: Central Banks and Networks in Canada and the United States William D. Coleman 8 Policy Networks, Opportunity Structures and Neo-Conservative Reform Strategies in Health Policy Marian Döhler 9 The Preconditions for Policy Networks: Some Findings from a Three-Country Study on Industrial Restructuring Patrick Kenis Contributor

Simulating the characteristics of tropical cyclones over the South West Indian Ocean using an adaptive Stretched-Grid Global Climate Model

Tropical Cyclones are one of the most devastating natural phenomena. Previous attempts to simulate Tropical Cyclones (TCs) over the South West Indian Ocean (SWIO) have used Global Circulation Models (GCMs) with uniform grid. This study examines the capability of a GCM with adaptive grid stretching (CAM-EULAG, hereafter CEU) in simulating the characteristics of TCs over the SWIO. In the study, the CEU model is applied with a fine horizontal grid resolution (0.5°x0.5°) over the SWIO and coarser resolution (1°x1° - 2°x2.25°) over the rest of the globe. The model simulation is performed for 11 years (1999-2010) and validated against the Joint Typhoon Warning Centre (JTWC) best track observation, Global Precipitation Climatology Project (GPCP) satellite data, and ERA-Interim (ERAINT) reanalysis data. The study also considers the impact of El Niño Southern Oscillation (ENSO), Indian Ocean Dipole (IOD) and the South Atlantic Subtropical Dipole (SASD) on TC counts over the SWIO

Discourse in ESOL research and design : the basic units

Despite the importance of the speech act as an analytic category, a general comprehensive\ud definition of it that allows for methodical definitions of particular\ud acts has not been provided. As a consequence, large areas of language use are\ud often treated inadequately, both in learning research and in course planning.\ud Among other problems, applied linguists presuppose different dimensions in discourse\ud and their codings of utterances are insufficiently reliable. Therefore, valid\ud comparisons regarding their empirical results or their design proposals are often\ud impossible.\ud The lack of definitions ESOL work requires is intimately associated to a\ud defective understanding of the nature of acts. Existing classifications separate\ud akin acts and group diverse ones together. To clarify the confusions, it is necessary\ud to distinguish sharply acts which make present, create or modify knowledge\ud from acts that set deontic conditions, ie acts like defining, classifying and\ud generalizing from acts like ordering, requesting and inviting. The first kind,\ud which are referred to here as dissertation acts, are not a subtype of illocutionary\ud acts, as has previously been considered. Rather, they constitute a category at the\ud same hierarchical leveL\ud The distinction is shown to be fundamental following the same approaches\ud that Strawson, Austin, Searle and Widdowson used to establish the sentence, the\ud proposition and the speech act as independent units. The discussion leads to two\ud general definitions of illocutionary and dissertation acts, which postulate a fixed\ud number of parameters for each. Sets of conceivable values for every parameter\ud are also delimited. Hence, a given combination of values determines a particular\ud act, and all possible acts are determinable.\ud The systematic framework thus produced suggests spiral research and teaching\ud programmes which, at different stages, focus on speech act elements, speech\ud acts and speech act combinations. These would allow analysts and students to\ud discern the global organization of a discourse from its final results. They might\ud also lead to a better understanding of its linguistic realization