1,064 research outputs found
Quaternary glacial evolution in the Central Cantabrian Mountains (Northern Spain)
Peer reviewedPostprin
Evaluation and combination of pitch estimation methods for melody extraction in symphonic classical music
The extraction of pitch information is arguably one of the most important
tasks in automatic music description systems. However, previous
research and evaluation datasets dealing with pitch estimation focused
on relatively limited kinds of musical data. This work aims to broaden
this scope by addressing symphonic western classical music recordings,
focusing on pitch estimation for melody extraction. This material is characterised
by a high number of overlapping sources, and by the fact that the
melody may be played by different instrumental sections, often alternating
within an excerpt. We evaluate the performance of eleven state-of-the-art
pitch salience functions, multipitch estimation and melody extraction algorithms
when determining the sequence of pitches corresponding to the
main melody in a varied set of pieces. An important contribution of the
present study is the proposed evaluation framework, including the annotation
methodology, generated dataset and evaluation metrics. The results
show that the assumptions made by certain methods hold better than
others when dealing with this type of music signals, leading to a better
performance. Additionally, we propose a simple method for combining
the output of several algorithms, with promising results
A Motivating Exploration on Lunar Craters and Low-Energy Dynamics in the Earth -- Moon System
It is known that most of the craters on the surface of the Moon were created
by the collision of minor bodies of the Solar System. Main Belt Asteroids,
which can approach the terrestrial planets as a consequence of different types
of resonance, are actually the main responsible for this phenomenon. Our aim is
to investigate the impact distributions on the lunar surface that low-energy
dynamics can provide. As a first approximation, we exploit the hyberbolic
invariant manifolds associated with the central invariant manifold around the
equilibrium point L_2 of the Earth - Moon system within the framework of the
Circular Restricted Three - Body Problem. Taking transit trajectories at
several energy levels, we look for orbits intersecting the surface of the Moon
and we attempt to define a relationship between longitude and latitude of
arrival and lunar craters density. Then, we add the gravitational effect of the
Sun by considering the Bicircular Restricted Four - Body Problem. As further
exploration, we assume an uniform density of impact on the lunar surface,
looking for the regions in the Earth - Moon neighbourhood these colliding
trajectories have to come from. It turns out that low-energy ejecta originated
from high-energy impacts are also responsible of the phenomenon we are
considering.Comment: The paper is being published in Celestial Mechanics and Dynamical
Astronomy, vol. 107 (2010
Foundations for the Design of a Creative System Based on the Analysis of the Main Techniques that Stimulate Human Creativity
This work presents the design of a computational system with creative capacity, based on the synthesis of the main methods that stimulate human creativity. When analyzing each method, a set of characteristics that the computer system must have in order to emulate a creative capacity has been suggested. In this way, by integrating all the suggestions in a structured way, it is possible to design the general architecture and functioning strategy of a computer system that has the incremental creative capacity of well-known creative methods. This computational system is designed as a multi-agent system, made up of two groups of agents, the problem solving group and the creative group, the first one exploring and evaluating paths for suitable solutions, the second implementing creative methods to generate new paths that are provided to the first group
A crowdsourcing-based system for monitoring em radiation exposure in Chile
Indexación: Scopus.Public concern about the possible effects on health due to electromagnetic (EM) radiation exposure has led to the definition of regulations worldwide. In Chile, the so-called "Ley de Antenas" provides a regulatory framework that establishes limits and special conditions in this regard. Although the official record of measurements is available in a public information portal, this approach is not scalable and intuitive enough for all interested users. This paper propose a participatory measurement system to extend the monitored areas based on the concern of citizens themselves. © 2018 CEUR-WS. All rights reserved.http://ceur-ws.org/Vol-2178/SSN2018_paper_7.pd
Neutrino oscillation physics with a higher -beam
The precision measurement and discovery potential of a neutrino factory based
on a storage ring of boosted radioactive ions (-beam) is re-examined. In
contrast with past designs, which assume ion factors of and
baselines of L=130 km, we emphasize the advantages of boosting the ions to
higher and increasing the baseline proportionally. In particular, we
consider a medium- scenario (, L=730 km) and a
high- scenario (, L = 3000 km).The increase in
statistics, which grow linearly with the average beam energy, the ability to
exploit the energy dependence of the signal and the sizable matter effects at
this longer baseline all increase the discovery potential of such a machine
very significantly.Comment: An error corrected, conclusions unchanged. Revised version to appear
in Nuclear Physics
Comparative assessment of RAMS and WRF short-term forecasts over Eastern Iberian Peninsula using various in-situ observations, remote sensing products and uncoupled land surface model datasets
The Regional Atmospheric Modeling System (RAMS) and the Weather Research and Forecasting (WRF) mesoscale models are being used for weather and air quality studies as well as forecasting tools in Numerical Weather Prediction (NWP) systems. In the current study, we perform a comparative assessment of these models under distinct typical atmospheric conditions, classified according to the dominant wind flow and cloudiness, over Eastern Iberian Peninsula. This study is focused on the model representation of key physical processes in terms of meteorology and surface variables during a 7-days period in summer 2011. The hourly outputs produced by these two models are compared not only with observed standard surface variables, measured at different permanent weather stations located over the region of study, but also with different surface remote sensing products and uncoupled Land Surface Models (LSM) datasets. Confronting RAMS and WRF, the current study highlights relevant differences over areas near the coast when mesoscale circulations or Eastern synoptic advections are developed over the region of study. A higher moisture content is observed under these atmospheric conditions, due to the moisture transport by the sea breeze inland. In this regard, it has been found that the Eastern wind field simulated by WRF reaches inland areas and comprises a larger sea breeze extension than RAMS. This sea breeze development impacts meteorology and surface variables in locations not too close to the coast, but still affected by land-sea winds. Additionally, WRF remains more windy and moister than RAMS at night-time, while alike results are found under Western synoptic advections. The results obtained in the current paper show differences under distinct dominant atmospheric conditions, which outline further research in this field in order to achieve more general conclusions
Applications of the ACGT Master Ontology on Cancer
In this paper we present applications of the ACGT Master Ontology (MO) which is a new terminology resource for a transnational network providing data exchange in oncology, emphasizing the integration of both clinical and molecular data. The development of a new ontology was necessary due to problems with existing biomedical ontologies in oncology. The ACGT MO is a test case for the application of best practices in ontology development. This paper provides an overview of the application of the ontology within the ACGT project thus far
Flow and clogging of a sheep herd passing through a bottleneck
We present an experimental study of a flock passing through a narrow door. Video monitoring of daily routines in a farm has enabled us to collect a sizable amount of data. By measuring the time lapse between the passage of consecutive animals, some features of the flow regime can be assessed. A quantitative definition of clogging is demonstrated based on the passage time statistics. These display broad tails, which can be fitted by power laws with a relatively large exponent. On the other hand, the distribution of burst sizes robustly evidences exponential behavior. Finally, borrowing concepts from granular physics and statistical mechanics, we evaluate the effect of increasing the door size and the performance of an obstacle placed in front of it. The success of these techniques opens new possibilities regarding their eventual extension to the management of human crowds
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