1,592 research outputs found
Efficiency and Equity in Schools around the World
Attention to the quality of human capital in different countries naturally leads to concerns about how school policies relate to student performance. The data from the Third International Mathematics and Science Study (TIMSS) provide a way of comparing performance in different schooling systems. The results of analyses of educational production functions within a range of developed and developing countries show general problems with the efficiency of resource usage similar to those found previously in the United States. These effects do not appear to be dictated by variations related to income level of the country or level of resources in the schools. Neither do they appear to be determined by school policies that involve compensatory application of resources. The conventional view that school resources are relatively more important in poor countries also fails to be supported.
Jitter and Shimmer measurements for speaker diarization
Jitter and shimmer voice quality features have been successfully
used to characterize speaker voice traits and detect voice pathologies.
Jitter and shimmer measure variations in the fundamental frequency
and amplitude of speaker's voice, respectively. Due to their nature, they can be used to assess differences between speakers. In this paper, we investigate the usefulness of these voice quality features in the task of speaker diarization. The combination of voice quality features with the conventional spectral features, Mel-Frequency Cepstral Coefficients (MFCC), is addressed in the framework of Augmented Multiparty Interaction (AMI) corpus, a multi-party and spontaneous speech set of recordings. Both sets of features are independently modeled using mixture of Gaussians and fused together at the score likelihood level. The experiments carried out on the AMI corpus show that incorporating jitter and shimmer measurements to the baseline spectral features decreases the diarization error rate in most of the recordings.Peer ReviewedPostprint (published version
Automated Meter Reading and SCADA Application for Wireless Sensor Network
Currently, there are many technologies available to automate
public utilities services (water, gas and electricity). AMR, Automated
Meter Reading, and SCADA, Supervisory Control and Data Acquisition,
are the main functions that these technologies must support. In
this paper, we propose a low cost network with a similar architecture to
a static ad-hoc sensor network based on low power and unlicensed radio.
Topological parameters for this network are analyzed to obtain optimal
performances and to derive a pseudo-range criterion to create an
application-specific spanning tree for polling optimization purposes. In
application layer services, we analytically study different polling schemes
Rachel Bowlby: Freudian Mythologies. Greek Tragedy and Modern Identities. Oxford University Press, Oxford, New York, 2007
Sin resume
The Impact of theoretical chemistry on biology
Els avenços en les bases dels mètodes teòrics i l'espectacular
desenvolupament de la potència de cà lcul han fet
possible progressar enormement en el somni dels fundadors
de la quÃmica, és a dir, ser capaços d'estudiar amb mètodes
computacionals el conjunt de processos quÃmics. Actualment,
la quÃmica teòrica està completant el darrer avenç: intentar esdevenir
l'eina més recent per a comprendre la naturalesa quÃmica
dels éssers vius. Aquesta revisió pretén mostrar com els
mètodes de la quÃmica teòrica, originalment desenvolupats per
a examinar molècules petites en fase gas, han evolucionat per
a assolir la complexa descripció de sistemes biològics.Recent advances in theoretical formalism together
with the dramatic development of computer infrastructure have
allowed enormous progress in achieving the dream of the
founders of chemistry: to submit the majority of chemical phenomena
to calculation. Currently, theoretical chemistry is working
towards reaching the next step: to become the ultimate tool
to understand the chemical nature of living organisms. This review
summarizes how techniques originally developed to represent
small molecules in the gas phase have evolved such
that they are able to describe the complex behaviors of biological
systems
Consideraciones tecnológicas sobre la talla laminar por presión: sistemas de sujeción
El empleo de modelos experimentales de talla en la reproducción de artefactos lÃticos,
permite una aproximación a la dinámica de fabricación de los objetos y a la comprensión
de ciertos aspectos técnicos integrados en el proceso de reducción.
La obtención de láminas por presión, exige el conocimiento y control de toda úna
serie de mecanismos de fabricación cuya aplicación y combinación implican un grado de
conocimiento técnico preciso.
En este avance presentamos alguno de los sistemas experimentales clásicos de
laminación, prestando especial atención a los sistemas de inmovilización del núcleo y al
modo de ejecución del esfuerzo. El control ejercido sobre alguno de los mecanismos de
fabricación empleados (parámetros mecánicos o variables independientes) y los
resultados obtenidos (parámetros morfológicos o variables dependientes), nos está
permitiendo comprender y explicar la morfologÃa de algunas láminas y la formación de
ciertas fracturas y accidentes de talla como resultado de la aplicación incorrecta de
ciertos mecanismos.Experimental too! replication allow us to a better understanding of teclmical issues in
prehistory. One of the more complex teclmic in lithic reduction is blade flaking by
pressure. In this paper we show sorne of the technical procedures employed, specially the
core holding methods. The application of this method in the courses developed at the
University Autónoma of Madrid allow us for a better understanding of different
morphologies, fractures and accidents in the blade production with pressure flaking
Temporally-aware algorithms for the classification of anuran sounds
Several authors have shown that the sounds of anurans can be used as an indicator of
climate change. Hence, the recording, storage and further processing of a huge
number of anuran sounds, distributed over time and space, are required in order to
obtain this indicator. Furthermore, it is desirable to have algorithms and tools for
the automatic classification of the different classes of sounds. In this paper, six
classification methods are proposed, all based on the data-mining domain, which
strive to take advantage of the temporal character of the sounds. The definition and
comparison of these classification methods is undertaken using several approaches.
The main conclusions of this paper are that: (i) the sliding window method attained
the best results in the experiments presented, and even outperformed the hidden
Markov models usually employed in similar applications; (ii) noteworthy overall
classification performance has been obtained, which is an especially striking result
considering that the sounds analysed were affected by a highly noisy background;
(iii) the instance selection for the determination of the sounds in the training dataset
offers better results than cross-validation techniques; and (iv) the temporally-aware
classifiers have revealed that they can obtain better performance than their nontemporally-aware
counterparts.ConsejerÃa de Innovación, Ciencia y Empresa (Junta de AndalucÃa, Spain): excellence eSAPIENS number TIC 570
De las mediaciones consentidas a las mediaciones deseadas. Lo masivo y lo colectivo en los procesos de comunicación
The model of communicative transformation must face the mediations imposed as representations of reality that colonize everyday life and demand the conception of Communications as collective and desired construction of the social mediations. This would imply the deconstruction of the institutional and massive features that keep the coherence of the symbolic universes and weaken the alter-natives that might make social change possible. This model considers the imposed mediations to unveil the existence of multidirectional communications processes, which are essential exchange and transformation spaces in the collective construction of social reality, enabling the desired mediations to counteract the overcrowding effect of the consented representations.El modelo de transformación comunicativa debe hacer frente a las mediaciones impuestas como representaciones de la realidad colonizadoras de la vida cotidiana y exigir la concepción de la comunicación como construcción colectiva y deseada de las mediaciones sociales. Supone esto la deconstrucción de lo institucional y lo masivo que mantiene la coherencia de los universos simbólicos y debilita las alternativas posibilitadoras del cambio social. Este modelo aprovecha las mediaciones impuestas para desvelar la existencia de procesos de comunicación multidireccional, que no son sino espacios de intercambio y de transformación imprescindibles en la construcción colectiva de la realidad social, que posibilitan las mediaciones deseadas capaces de contrarrestar el efecto de masificación de las representaciones consentidas
Manejo del torque con aparatologÃa fija en ortodoncia
El documento digital no refiere asesorRevisa y analiza la literatura cientÃfica conjuntamente con la presentación de un caso clÃnico con el eje temático manejo del torque con aparatologÃa fija en ortodoncia. En esencia, la técnica arco de canto (edgewise estándar) exige hacer dobleces de primer, segundo y tercer orden. Este último es expresado principalmente con la torsión de alambres rectangulares. Existe diferentes tipos de torque y su manejo se convierte en una variable muy importante en las diferentes fases de tratamiento siendo su mayor utilidad en la fase de finalización para establecer una adecuada función incisal, canina y asentamiento posterior de las cúspides funcionales en su fosa antagonista. La expresión del torque es afectada por muchos factores como el tamaño del slot del bracket, su posición-deformación, el calibre del alambre y el modo de ligación arco-bracket. Si bien la técnica de arco recto (edgewise preajusted) ha disminuido la necesidad de doblar alambres, no nos exime de hacer dobleces de compensación para cada maloclusión, aumentando, disminuyendo o neutralizando la información prefabricada de los brackets. Su cuantificación generalmente es hecha en grados y Nmm; sin embargo, su dosificación sigue siendo difÃcil en la práctica clÃnica. Tweed y posteriormente Interlandi, además de proponer una clasificación de torques, sugieren su dosificación y cuantificación mediante la distancia con que se eleva el extremo opuesto del arco en relación a una horizontal verdadera que pasa por la mitad del alicate. El presente trabajo tiene como objetivo hacer una revisión y análisis crÃtico de la literatura cientÃfica conjuntamente con el reporte de caso clÃnico.Trabajo académic
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