577 research outputs found
Repeatability of push-up and push-down methods in the measure of accommodation amplitude
La mesura de l’amplitud d’acomodaciĂł Ă©s una prĂ ctica molt habitual en optometria. La majoria de professionals coincideixen en que els mètodes push-up i push-down sĂłn els mĂ©s utilitzats als exĂ mens visuals degut al fet que sĂłn mètodes rĂ pids, fĂ cils i eficaços. Tot i això, Ă©s important saber la concordança entre cada mètode per tal de realitzar diagnòstics correctes. En aquest estudi, s’han comparat els resultats en diòptries dels mètodes push-up i push-down. Per tal de dur a terme l’estudi, s’ha mesurat l’amplitud d’acomodaciĂł a 12 pacients, dues vegades, prenent 3 mesures en cada repeticiĂł. Per avaluar la concordança entre mètodes s’han utilitzat el paired-T test, el Shapiro-wilk test i el grĂ fics de Bland and Altman. L’anĂ lisi estadĂstic de les dades mesurades s’ha fet per tal d’estudiar ambdĂłs mètodes. Els resultats no han mostrat diferències significatives entre el mètode del push-up i el del push-down
Notes concerning reporting in the Middle East
Notes concerning reporting in the Middle Eas
Those of us who didn´t get to Baghdag
Those of us who didn´t get to Baghda
Notes al voltant de la informaciĂł a Orient MitjĂ
Notes al voltant de la informaciĂł a Orient Mitj
Models and estimators for markerless human motion tracking
In this work, we analyze the diferent components of a model-based motion tracking system.
The system consists in: a human body model, an estimator, and a likelihood or cost
function
Fraud detection in energy consumption: a supervised approach
Data from utility meters (gas, electricity, water) is a rich source of information for distribution companies, beyond billing. In this paper we present a supervised technique, which primarily but not only feeds on meter information, to detect meter anomalies and customer fraudulent behavior (meter tampering). Our system detects anomalous meter readings on the basis of models built using machine learning techniques on past data. Unlike most previous work, it can incrementally incorporate the result of field checks to grow the database of fraud and non-fraud patterns, therefore increasing model precision over time and potentially adapting to emerging fraud patterns. The full system has been developed with a company providing electricity and gas and already used to carry out several field checks, with large improvements in fraud detection over the previous checks which used simpler techniques.Peer ReviewedPostprint (author's final draft
RemodelaciĂłn y ampliaciĂłn del "CamĂ de les Espadelles"
El objetivo principal ha sido aplicar los conocimientos adquiridos durante
nuestro paso por la EPSEB en el presente proyecto de remodelación del “Camà de les
Espadelles”. Este objetivo se puede desglosar en dos grandes bloques, el primero de
ellos serĂa aplicar los conocimientos adquiridos en los campos de la geodesia y la
tecnologĂa GPS para la creaciĂłn de una red geodĂ©sica que sirva como base para un
levantamiento topográfico. En cuanto al segundo gran bloque, se trata de la aplicación
de los conocimientos adquiridos en campos como la aplicación de técnicas topográficas
en la obra ( creaciĂłn de superficies virtuales, creaciĂłn de ejes, perfiles longitudinales,
transversales… ).
MĂ©todos.
Se ha creado una pequeña red geodésica ligada a la red CatNet del “Institut
CartogrĂ fic de Catalunya” que ha sido compensada por mĂnimos cuadrados a travĂ©s del
software SKI-Pro de la marca Leica.
Mediante la calculadora geodésica del “Institut Cartogrà fic de Catalunya”, se
han transformado las coordenadas obtenidas de geodésicas WGS84 y altura elipsoidal a
coordenadas UTM ED50 y altura ortométrica.
Para el diseño del trazado de han utilizado los programas AutoCad y MDT tanto
para la planta como para el alzado, asà como también para la confección de los planos.
Resultados.
Los resultados detallados se muestran en la memoria y los anejos del proyecto,
pero como breve resumen se muestra un listado con los apartados más significativos del
proyecto.
- Coordenadas UTM ED50 y altura ortométrica.
- Listado nube de puntos.
- Listado eje en planta.
- Listado eje en alzado.
- Listado de volĂşmenes
Habitat and scale shape the demographic fate of the keystone sea urchin <i>Paracentrotus lividus</i> in Mediterranean macrophyte communities
Demographic processes exert different degrees of control as individuals grow, and in species that span several habitats and spatial scales, this can influence our ability to predict their population at a particular life-history stage given the previous life stage. In particular, when keystone species are involved, this relative coupling between demographic stages can have significant implications for the functioning of ecosystems. We examined benthic and pelagic abundances of the sea urchin Paracentrotus lividus in order to: 1) understand the main life-history bottlenecks by observing the degree of coupling between demographic stages; and 2) explore the processes driving these linkages. P. lividus is the dominant invertebrate herbivore in the Mediterranean Sea, and has been repeatedly observed to overgraze shallow beds of the seagrass Posidonia oceanica and rocky macroalgal communities. We used a hierarchical sampling design at different spatial scales (100 s, 10 s and <1 km) and habitats (seagrass and rocky macroalgae) to describe the spatial patterns in the abundance of different demographic stages (larvae, settlers, recruits and adults). Our results indicate that large-scale factors (potentially currents, nutrients, temperature, etc.) determine larval availability and settlement in the pelagic stages of urchin life history. In rocky macroalgal habitats, benthic processes (like predation) acting at large or medium scales drive adult abundances. In contrast, adult numbers in seagrass meadows are most likely influenced by factors like local migration (from adjoining rocky habitats) functioning at much smaller scales. The complexity of spatial and habitat-dependent processes shaping urchin populations demands a multiplicity of approaches when addressing habitat conservation actions, yet such actions are currently mostly aimed at managing predation processes and fish numbers. We argue that a more holistic ecosystem management also needs to incorporate the landscape and habitat-quality level processes (eutrophication, fragmentation, etc.) that together regulate the populations of this keystone herbivore
Importance of within-shoot epiphyte distribution for the carbon budget of seagrasses: the example of Posidonia oceanica
6 páginas, 4 figuras, 1 tablaTo assess the effects of shading by epiphytes on the carbon
balance of the seagrass Posidonia oceanica, we
examined the patterns of within-shoot epiphyte abundance
on leaves, and their variability with season and
depth. Epiphyte biomass was found to depend on leaf
age (larger epiphyte load on older tissues), leaf side (more
epiphytes on the inner face than on the outer) and depth
(more epiphytes in deep meadows). Depth differences
were maximum in spring and disappeared in late summer.
Percent light absorbed (absorptance) by epiphytes
was measured; light absorptance followed an exponential-
saturated model with epiphyte biomass. Combining
these data of percent light absorbed, within-shoot epiphyte
biomass distribution and an existing carbon balance
model, we conclude that reduction in carbon gains
caused by epiphyte shading is relatively small, and greater
in deep meadows (8.8% on average, with values up
to 14.2% in May) than that in shallow water (4.7% on
average with maximum values of 7% in August). This is
mainly due to the accumulation of epiphytes on old tissues,
which contribute only marginally to the carbon gain
of the plant. Using the same procedure, we modelled the
effects of a doubling in epiphyte biomass, conserving the
observed within-shoot distribution. The result was a very
small additional carbon loss. However, using the same
biomass but modifying the distribution (shifting the same
abundance towards younger leaf age classes), the reduction
in carbon gains was dramatic, particularly in deep
meadows (between 21% and 41%, depending on the
shift used). Therefore, it is the epiphyte growth timing rate
rather than the final biomass reached which seems to be
a key control for Posidonia oceanica survival, especially
near the deep limit of its distribution.Financial support
was provided by a grant from CICYT (REN2002-04020).Peer reviewe
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