How do domestic policies affect the integration of Ethiopian fertiliser markets with world markets?

Frequent shifts in policy on fertiliser markets have occurred in Ethiopia with the aim of facilitating both physical and economic access of farmers to fertiliser. The last shift was the introduction of a monopoly on each stage of the supply chain in 2008. Furthermore, government control of prices and margins as well as stockholding programmes are also present on the markets. This paper evaluates the effect of these policies on the integration of domestic with world markets of fertiliser, using cointegration methods. Time series data of diammonium phosphate (DAP) and urea prices on world, import and retail markets between 1971 and 2012 are used. The findings show high transmission of price signals from world markets to import prices for both DAP and urea. However, between import and retail prices there is no evidence of cointegration for urea, while for DAP full price transmission is concluded. In the retail market, domestic transaction costs associated with storing large volumes of fertiliser act as a buffer between import and retail prices, especially for urea. Therefore, economic benefits could be achieved by reducing the size of stocks and revising the demand estimation process.

MARVEL: A System for Recognizing World Locations with Stereo Vision

To use a world model, a mobile robot must be able to determine its own position in the world. To support truly autonomous navigation, I present MARVEL, a system that builds and maintains its own models of world locations and uses these models to recognize its world position from stereo vision input. MARVEL is designed to be robust with respect to input errors and to respond to a gradually changing world by updating its world location models. I present results from real-world tests of the system that demonstrate its reliability. MARVEL fits into a world modeling system under development.

Surface Reflectance Recognition and Real-World Illumination Statistics

Humans distinguish materials such as metal, plastic, and paper effortlessly at a glance. Traditional computer vision systems cannot solve this problem at all. Recognizing surface reflectance properties from a single photograph is difficult because the observed image depends heavily on the amount of light incident from every direction. A mirrored sphere, for example, produces a different image in every environment. To make matters worse, two surfaces with different reflectance properties could produce identical images. The mirrored sphere simply reflects its surroundings, so in the right artificial setting, it could mimic the appearance of a matte ping-pong ball. Yet, humans possess an intuitive sense of what materials typically "look like" in the real world. This thesis develops computational algorithms with a similar ability to recognize reflectance properties from photographs under unknown, real-world illumination conditions. Real-world illumination is complex, with light typically incident on a surface from every direction. We find, however, that real-world illumination patterns are not arbitrary. They exhibit highly predictable spatial structure, which we describe largely in the wavelet domain. Although they differ in several respects from the typical photographs, illumination patterns share much of the regularity described in the natural image statistics literature. These properties of real-world illumination lead to predictable image statistics for a surface with given reflectance properties. We construct a system that classifies a surface according to its reflectance from a single photograph under unknown illuminination. Our algorithm learns relationships between surface reflectance and certain statistics computed from the observed image. Like the human visual system, we solve the otherwise underconstrained inverse problem of reflectance estimation by taking advantage of the statistical regularity of illumination. For surfaces with homogeneous reflectance properties and known geometry, our system rivals human performance.

A First approximation to the realism/idealism debate about the external world

El text intenta fer una primera aproximació al debat contemporani entre realistes i anti-realistes sobre el món empíric, centrant-se en les posicions de Putnam i Nagel. El seu objectiu principal és el d'entendre les motivacions de les posicions i l'estructura actual del debat, i el d'establir les característiques que hauria de tenir qualsevol posició satisfactòria

Los campesinos más allá de la victimización, la criminalización y la invisibilización: un estudio de las representaciones de los campesinos en la prensa

La figura del campesino, primero en Europa y posteriormente en el mundo, por lo general ha estado ligada a estereotipos asociados a la marginalidad, la pobreza y el atraso. Estas representaciones poco a poco han tomado fuerza en nuestra sociedad y parecen inmodificables a través del tiempo. Lo que hace interesante su análisis es el hecho de que en la mayoría de los casos las representaciones no corresponden a la realidad, son contradictorias y se dan como resultado de lecturas poco objetivas construidas por parte de unos pocos.

TU Graz: Course: 707.000 Web Science and Web Technology: Lecture 2: Small World Problem

We will discuss several examples and research efforts related to the small world problem and set the ground for our discussion of network theory and social network analysis. Readings: An Experimental Study of the Small World Problem, J. Travers and S. Milgram Sociometry 32 425-443 (1969) [Protected Access] Optional: The Strength of Weak Ties, M.S. Granovetter The American Journal of Sociology 78 1360--1380 (1973) [Protected Access] Optional: Worldwide Buzz: Planetary-Scale Views on an Instant-Messaging Network, J. Leskovec and E. Horvitz MSR-TR-2006-186. Microsoft Research, June 2007. [Web Link, the most recent and comprehensive study on the subject!] Originally from: http://kmi.tugraz.at/staff/markus/courses/SS2008/707.000_web-science/

Networked Life: Module CIS 112, University of Pennsylvania, Spring 2008

What kind of science is appropriate for understanding the Facebook? How does Google find what you're looking for... ...and exactly how do they make money doing so? What structural properties might we expect any social network to have? How does your position in an economic network (dis)advantage you? How are individual and collective behavior related in complex networks? What might we mean by the economics of spam? What do game theory and the Paris subway have to do with Internet routing? What's going on in the pictures to the left and right? Networked Life looks at how our world is connected -- socially, economically, strategically and technologically -- and why it matters. The answers to the questions above are related. They have been the subject of a fascinating intersection of disciplines including computer science, physics, psychology, mathematics, economics and finance. Researchers from these areas all strive to quantify and explain the growing complexity and connectivity of the world around us, and they have begun to develop a rich new science along the way. Networked Life will explore recent scientific efforts to explain social, economic and technological structures -- and the way these structures interact -- on many different scales, from the behavior of individuals or small groups to that of complex networks such as the Internet and the global economy. This course covers computer science topics and other material that is mathematical, but all material will be presented in a way that is accessible to an educated audience with or without a strong technical background. The course is open to all majors and all levels, and is taught accordingly. There will be ample opportunities for those of a quantitative bent to dig deeper into the topics we examine. The majority of the course is grounded in scientific and mathematical findings of the past two decades or less.

Experiencias de estigma de enfermos mentales con trabajadores de la salud en Colombia

Los conceptos para la comprensión del estigma, inician con Goffman en los años sesenta, hasta los estudios de los noventa liderados la World Psychiatri Asociation (WPA). ¿Cómo se crea el estigma?, ¿cómo se difunde? y ¿que efectos tiene sobre los enfermos mentales, sus familias, la sociedad y los sistemas de salud?; es necesario caracterizarlas. Diferencias entre los países desarrollados y en vía de desarrollo, en las características del estigma, sus efectos y consecuencias se han observado; podrían explicarse por las diferencias socioculturales. Este artículo busca determinar cuáles y como son las experiencias que los pacientes mentales crónicos tienen con los trabajadores de la salud en siete regiones colombianas y que factores se encuentran asociados a éstas. Es uno de los objetivos específicos de un protocolo que evalúa otros aspectos del estigma; para la caracterización de las experiencias de estigma en Colombia. Se aplicó entrevista tipo encuesta (Inventario de Experiencias de Estigma), auto diligenciad, a quinientos pacientes de siete regiones del país; la cual se usa en investigaciones de la WPA. Se hallaron niveles bajos pero significativos, de experiencias de estigma con los trabajadores de la salud, se evidenció que la mayoría de experiencias están relacionadas con el llamado “estigma estructural”, de igual manera aparecen algunos factores asociados como el tipo de institución donde ha sido hospitalizado, el numero de hospitalizaciones, el tipo de persona con la que convive, y haber recurrido a la tutela, entre otros.

Social Networks and Small World phenomena

Social Networking tools like Facebook yield recognisable small world phenomena, that is particular kinds of social graphs that facilitate particular kinds of interaction and information exchange.

An introduction to Authentic World drug calculations

This 8 minute video provides a brief introduction to Authentic World, a website available to students in Health Sciences that enables them to practice drug calculations, get feedback on their performance and be formally assessed.

The Curriculum Innovation Programme at the University of Southampton: Curriculum design for a post-Browne world

This is a narrated slide presentation of a seminar delivered by Dr. Peter Smith, Associate Dean (Education) Faculty of Law, Arts and Social Sciences/Associate Dean Education and Student Experience Faculty of Social and Human Sciences. The recording lasts around 25 minutes. The seminar was delivered on 30 November, 2010 to the University of Southampton Higher Education Research Group. The presentation reflects the position of the University's Curriculum Innovation Programme as of November 2010/January 2011.

Lego is no only the world of child

Research Presentations

Week 1 - Our Digital World

Introductory lecture for engineering foundation year Computer Applications module.