13,626 research outputs found
An Evolutionary Algorithm to Generate Real Urban Traffic Flows
In this article we present a strategy based on an evolutionary algorithm to calculate the real vehicle ows in cities according to data from sensors placed in the streets. We have worked with a map imported from OpenStreetMap into the SUMO traffic simulator so that the resulting scenarios can be used to perform different optimizations with the confidence of being able to work with a traffic distribution close to reality. We have compared the results of our algorithm to other competitors and achieved results that replicate the real traffic distribution with a precision higher than 90%.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This research has been partially funded by project number 8.06/5.47.4142 in collaboration with the VSB-Technical University of Ostrava and Universidad de Málaga UMA/FEDER FC14-TIC36, programa de fortalecimiento de las capacidades de I+D+i en las universidades 2014-2015, de la Consejería de Economía, Innovación, Ciencia y Empleo, cofinanciado por el fondo europeo de desarrollo regional (FEDER). Also, partially funded by the Spanish MINECO project TIN2014-57341-R (http://moveon.lcc.uma.es). The authors would like to thank the FEDER of European Union for financial support via project Movilidad Inteligente: Wi-Fi, Rutas y Contaminación (maxCT) of the "Programa Operativo FEDER de Andalucía 2014-2020. We also thank all Agency of Public Works of Andalusia Regional Government staff and researchers for their dedication and professionalism. Daniel H. Stolfi is supported by a FPU grant (FPU13/00954) from the Spanish Ministry of Education, Culture and Sports
Diagonal deformations of thin center vortices and their stability in Yang-Mills theories
The importance of center vortices for the understanding of the confining
properties of SU(N) Yang-Mills theories is well established in the lattice.
However, in the continuum, there is a problem concerning the relevance of
center vortex backgrounds. They display the so called Savvidy-Nielsen-Olesen
instability, associated with a gyromagnetic ratio for the
off-diagonal gluons.
In this work, we initially consider the usual definition of a {\it thin}
center vortex and rewrite it in terms of a local color frame in SU(N)
Yang-Mills theories. Then, we define a thick center vortex as a diagonal
deformation of the thin object. Besides the usual thick background profile,
this deformation also contains a frame defect coupled with gyromagnetic ratio
, originated from the charged sector. As a consequence, the
analysis of stability is modified. In particular, we point out that the defect
should stabilize a vortex configuration formed by a pair of straight components
separated by an appropriate finite distance.Comment: 20 pages, LaTe
Spin 3 cubic vertices in a frame-like formalism
Till now most of the results on interaction vertices for massless higher spin
fields were obtained in a metric-like formalism using completely symmetric
(spin-)tensors. In this, the Lagrangians turn out to be very complicated and
the main reason is that the higher the spin one want to consider the more
derivatives one has to introduce. In this paper we show that such
investigations can be greatly simplified if one works in a frame-like
formalism. As an illustration we consider massless spin 3 particle and
reconstruct a number of vertices describing its interactions with lower spin 2,
1 and 0 ones. In all cases considered we give explicit expressions for the
Lagrangians and gauge transformations and check that the algebra of gauge
transformations is indeed closed.Comment: 17 pades, no figure
Spectral classification of short numerical exon and intron sequences
This research presents three new numerical representations for classifying short exon and intron sequences using discrete Fourier transform period-3 value. Based on the human genome, results indicate that the Complex Twin-Pair representation is attractive compared with other numerical representations and the approach has potential applications in genome annotation and read mapping
High-Field Superconductivity at an Electronic Topological Transition in URhGe
The emergence of superconductivity at high magnetic fields in URhGe is
regarded as a paradigm for new state formation approaching a quantum critical
point. Until now, a divergence of the quasiparticle mass at the metamagnetic
transition was considered essential for superconductivity to survive at
magnetic fields above 30 tesla. Here we report the observation of quantum
oscillations in URhGe revealing a tiny pocket of heavy quasiparticles that
shrinks continuously with increasing magnetic field, and finally disappears at
a topological Fermi surface transition close to or at the metamagnetic field.
The quasiparticle mass decreases and remains finite, implying that the Fermi
velocity vanishes due to the collapse of the Fermi wavevector. This offers a
novel explanation for the re-emergence of superconductivity at extreme magnetic
fields and makes URhGe the first proven example of a material where magnetic
field-tuning of the Fermi surface, rather than quantum criticality alone,
governs quantum phase formation.Comment: A revised version has been accepted for publication in Nature Physic
Five tips for China to realize its co-targets of climate mitigation and Sustainable Development Goals (SDGs)
In 2018, a total of US$166 billion global economic losses and a new high of 55.3 Gt of CO2 equivalent emission were generated by 831 climate-related extreme events. As the world's largest CO2 emitter, we reported China's recent progresses and pitfalls in climate actions to achieve climate mitigation targets (i.e., limit warming to 1.5–2°C above the pre-industrial level). We first summarized China's integrated actions (2015 onwards) that benefit both climate change mitigation and Sustainable Development Goals (SDGs). These projects include re-structuring organizations, establishing working goals and actions, amending laws and regulations at national level, as well as increasing social awareness at community level. We then pointed out the shortcomings in different regions and sectors. Based on these analyses, we proposed five recommendations to help China improving its climate policy strategies, which include: 1) restructuring the economy to balance short-term and long-term conflicts; 2) developing circular economy with recycling mechanism and infrastructure; 3) building up unified national standards and more accurate indicators; 4) completing market mechanism for green economy and encouraging green consumption; and 5) enhancing technology innovations and local incentives via bottom-up actions
New Chiral Phases of Superfluid 3He Stabilized by Anisotropic Silica Aerogel
A rich variety of Fermi systems condense by forming bound pairs, including
high temperature [1] and heavy fermion [2] superconductors, Sr2RuO4 [3], cold
atomic gases [4], and superfluid 3He [5]. Some of these form exotic quantum
states having non-zero orbital angular momentum. We have discovered, in the
case of 3He, that anisotropic disorder, engineered from highly porous silica
aerogel, stabilizes a chiral superfluid state that otherwise would not exist.
Additionally, we find that the chiral axis of this state can be uniquely
oriented with the application of a magnetic field perpendicular to the aerogel
anisotropy axis. At suffciently low temperature we observe a sharp transition
from a uniformly oriented chiral state to a disordered structure consistent
with locally ordered domains, contrary to expectations for a superfluid glass
phase [6].Comment: 6 pages, 4 figure, and Supplementary Informatio
Robot-assisted laparoscopic surgery of the infrarenal aorta: The early learning curve
Background Recently introduced robot-assisted laparoscopic surgery (RALS) facilitates endoscopic surgical manipulation and thereby reduces
the learning curve for (advanced) laparoscopic surgery. We present our learning curve with RALS for aortobifemoral bypass
grafting as a treatment for aortoiliac occlusive disease.
Methods Between February 2002 and May 2005, 17 patients were treated in our institution with robot-assisted laparoscopic aorto-bifemoral
bypasses. Dissection was performed laparoscopically and the robot was used to make the aortic anastomosis. Operative time,
clamping time, and anastomosis time, as well as blood loss and hospital stay, were used as parameters to evaluate the results
and to compare the first eight (group 1) and the last nine patients (group2).
Results Total median operative, clamping, and anastomosis times were 365 min (range: 225–589 min), 86 min (range: 25–205 min), and
41 min (range: 22–110 min), respectively. Total median blood loss was 1,000 ml (range: 100–5,800 ml). Median hospital stay
was 4 days (range: 3–57 days). In this series 16/18 anastomoses were completed with the use of the robotic system. Three patients
were converted (two in group 1, one in group 2), and one patient died postoperatively (group 1). Median clamping and anastomosis
times were significantly different between groups 1 and 2 (111 min [range: 85–205 min] versus 57.5 min [range: 25–130 min],
p < 0.01 and 74 min [range: 40–110 min] versus 36 min [range: 22–69 min], p < 0.01, respectively) Total operative time, blood loss, and hospital stay showed no significant difference between groups
1 and 2.
Conclusions Robot-assisted aortic anastomosis was shown to have a steep learning curve with considerable reduction of clamping and anastomosis
times. However, due to a longer learning curve for laparoscopic dissection of the abdominal aorta, operation times were not
significantly shortened. Even with robotic assistance, laparoscopic aortoiliac surgery remains a complex procedure
Equality of Participation Online Versus Face to Face: Condensed Analysis of the Community Forum Deliberative Methods Demonstration
Online deliberation may provide a more cost-effective and/or less inhibiting
environment for public participation than face to face (F2F). But do online
methods bias participation toward certain individuals or groups? We compare F2F
versus online participation in an experiment affording within-participants and
cross-modal comparisons. For English speakers required to have Internet access
as a condition of participation, we find no negative effects of online modes on
equality of participation (EoP) related to gender, age, or educational level.
Asynchronous online discussion appears to improve EoP for gender relative to
F2F. Data suggest a dampening effect of online environments on black
participants, as well as amplification for whites. Synchronous online voice
communication EoP is on par with F2F across individuals. But individual-level
EoP is much lower in the online forum, and greater online forum participation
predicts greater F2F participation for individuals. Measured rates of
participation are compared to self-reported experiences, and other findings are
discussed.Comment: 14 pages, 10 tables, to appear in Efthimios Tambouris, Panos
Panagiotopoulos, {\O}ystein S{\ae}b{\o}, Konstantinos Tarabanis, Michela
Milano, Theresa Pardo, and Maria Wimmer (Editors), Electronic Participation:
Proceedings of the 7th IFIP WG 8.5 International Conference, ePart 2015
(Thessaloniki, August 30-September 2), Springer LNCS Vol. 9249, 201
Bright single-photon sources in bottom-up tailored nanowires
The ability to achieve near-unity light extraction efficiency is necessary
for a truly deterministic single photon source. The most promising method to
reach such high efficiencies is based on embedding single photon emitters in
tapered photonic waveguides defined by top-down etching techniques. However,
light extraction efficiencies in current top-down approaches are limited by
fabrication imperfections and etching induced defects. The efficiency is
further tempered by randomly positioned off-axis quantum emitters. Here, we
present perfectly positioned single quantum dots on the axis of a tailored
nanowire waveguide using bottom-up growth. In comparison to quantum dots in
nanowires without waveguide, we demonstrate a 24-fold enhancement in the single
photon flux, corresponding to a light extraction efficiency of 42 %. Such high
efficiencies in one-dimensional nanowires are promising to transfer quantum
information over large distances between remote stationary qubits using flying
qubits within the same nanowire p-n junction.Comment: 19 pages, 6 figure
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