Action, Time and Space in Description Logics

Description Logics (DLs) are a family of logic-based knowledge representation (KR) formalisms designed to represent and reason about static conceptual knowledge in a semantically well-understood way. On the other hand, standard action formalisms are KR formalisms based on classical logic designed to model and reason about dynamic systems. The largest part of the present work is dedicated to integrating DLs with action formalisms, with the main goal of obtaining decidable action formalisms with an expressiveness significantly beyond propositional. To this end, we offer DL-tailored solutions to the frame and ramification problem. One of the main technical results is that standard reasoning problems about actions (executability and projection), as well as the plan existence problem are decidable if one restricts the logic for describing action pre- and post-conditions and the state of the world to decidable Description Logics. A smaller part of the work is related to decidable extensions of Description Logics with concrete datatypes, most importantly with those allowing to refer to the notions of space and time

Mortality characteristics in sumadija district from 2010 – 2017

Mortality rate represents a number of deaths on a particular territory per time unit. There are general and specific mortalities. The aims at analysing the characteristics of mortality in Sumadija District for the time period ranging from 2010 – 2017. The study includes all death cases in the District of Sumadija in period 2010-2017, 34681 cases. The data are described and analysed with χ² test and linear trend. The trend analysis does not indicate any significant vari-ations during the given time span. The gender analysis re-veals that there is a significantly higher number of deceased persons among male population (52.2%, 47.8%, р<0.05). The average age of the deceased females (76.2±13.4) was higher than the average age of males (73.8±14.1) (р<0.05). The cause-specific analysis shows that natural causes of death dominate absolutely (96.5%) over violent deaths (2.7%) and undetermined causes (0.8%). The distribution of death causes according to ICD 10 shows that the most frequent causes of death are heart and blood vessel diseases, respiratory and neoplasm diseases. The life expectancy of the inhabitants of Sumadija District is increasing over time. There was a slight decrease in the mortality rates during the observed time period. The highest number of the deceased people is 65 or more years old. Men have higher mortality rates throughout their lives. Natural death and non-communicable diseases are dominant. The most common causes of death are heart and blood vessels diseases, in women, and respiratory and neo-plasm diseases, in men

Un estudio del contenido científico de las preguntas formuladas por estudiantes cuando intentan comprender dispositivos experimentales

Se muestra un análisis descriptivo del contenido científico de las preguntas formuladas por estudiantes de secundaria y universitarios, cuando tratan de comprender el funcionamiento de dispositivos experimentales. Se consideran tres situaciones didácticas habituales: leer un texto acompañado de imágenes estáticas (esquemáticas); visualizar imágenes dinámicas (video o demostración de cátedra), observar y manipular los dispositivos. Solo una tercera parte de las preguntas de los estudiantes contuvieron algún término científico, aunque los universitarios superaron claramente a los de secundaria. Las leyes y principios científicos, necesarios para modelizar y explicar la realidad, apenas fueron mencionadas por porcentajes muy pequeños de estudiantes, incluso universitarios. Así mismo, se encontraron errores conceptuales e ideas animistas preocupantes. La condición observar y manipular, típica de laboratorios escolares y de museos interactivos, estimuló mayor proporción de preguntas y mayor variedad en el uso de términos científicos en los estudiantes

Investigando el “agujero de ozono” en la Patagonia Austral

En este trabajo se presenta una introducci&oacute;n al conocimiento del fen&oacute;meno de la dr&aacute;stica disminuci&oacute;n en la concentraci&oacute;n de ozono estratosf&eacute;rico en primavera, que se ha dado en llamar &ldquo;agujero de ozono&rdquo;. Consta de dos partes: en la primera se realiza una caracterizaci&oacute;n del ozono, su distribuci&oacute;n, los procesos de generaci&oacute;n y destrucci&oacute;n, el &ldquo;agujero de ozono&rdquo; y su influencia en la biosfera. En la segunda parte se presentan los grupos de investigaci&oacute;n sobre ozono y radiaci&oacute;n UV que trabajan en la Patagonia