1,209 research outputs found
Diet of Common buzzard (Buteo buteo) (Linnaeus, 1758) in an area of Northwestern Spain as assessed by direct observation from blinds
Accuracy of raptor diet assessments can vary depending on the technique employed. In the available studies
in Spain, the Common buzzard (Buteo buteo) shows a diverse and non-specialized diet, reflecting local and
seasonal variation in the prey availability. This study reports information on the diet of the Common buzzard in
an area of Northwestern Spain, on the basis of direct observation during 308 h. of four nests from blinds. The
delivery prey rate to the nest was of 0.49 ± 0.04 items per hour. From a total of 145 prey delivered to the nests,
64.7% could be determined to the taxonomic level of class, 34.5% to the levels of species, genus or suborder
and a 34.5% were undetermined prey items. Mammals and reptiles were the most frequent preys in their diet,
while amphibians and birds were much less frequent. These results obtained are in agreement with those from
previous studies carried out in the North of Spain based on other assessments raptor diet techniques
Multiport Multiband Decoupling Optimization for Miniature Antennas
Multiband multiport antennas are increasingly used for wireless communications and sensing miniature devices. The equations governing the multiport multiband antennas are analyzed in this paper with the objective of drawing the design guidelines for low coupling small antennas. Those guidelines have been applied in the design and optimization of a two-port dual band small antenna of size around λ0/13 x λ0/13 at the lowest frequency. Certain coupling conditions are applied to the port loads achieving a coupling reduction of 8 dB when having a simple two-element real load. A reduction of 27 dB can be obtained when having ideal loads composed by a higher number of elements. The antenna geometry is shown together with coupling minimization results
Smart Beam Management for Vehicular Networks Using ML
[EN] The mmWave frequencies will be widely used in future
vehicular communications. At these frequencies, the radio
channel becomes much more vulnerable to slight changes in the
environment like motions of the device, reflections or blockage. In
high mobility vehicular communications the rapidly changing
vehicle environments and the large overheads due to frequent
beam training are the critical disadvantages in developing these
systems at mmWave frequencies. Hence, smart beam
management procedures are desired to establish and maintain the
radio channels. In this paper, we propose that using the positions
and respective velocities of the vehicles in the dynamic selection
of the beam pair, and then adapting to the changing environments
using ML algorithms, can improve both network performance
and communication stability in high mobility vehicular
communications.This work was supported by the Spanish Comision
Interministerial de Ciencia y Tecnologia (CICYT) under
projects TEC2016-78028-C3-1-P and MDM2016-O6OO,
Catalan Research Group 2017 SGR 21, and Industrial
Doctorate programme (2018-DI-084) of Generalitat de
Catalunya.Bharath-Reddy, G.; Montero, L.; Perez-Romero, J.; Molins-Benlliure, J.; Ferrando Bataller, M.; Molina, J.; Romeu, J.... (2021). Smart Beam Management for Vehicular Networks Using ML. Íñigo Cuiñas Gómez. 1-4. http://hdl.handle.net/10251/1910661
Vehicular mm-Wave Array for Smart Handover
[EN] The emergence of new technologies such as autonomous
vehicles and high data rate 5G networks requires advanced
antenna types that are capable of fulfilling requirements for
highly demanding wireless communication links. The array of
microstrip-fed slot-coupled patches is one such type of antenna
that provides low return loss and good transient behaviour for
broadband applications. A compact size slot-coupled patch
antenna subarray and its phased array is proposed in this paper.
Two different substrates Rogers TMM4 and Green TapeTM 951
Low Temperature Co-Fired Ceramic (LTCC) are considered for
the fabrication of microstrip feedline. The feedline is fabricated
on the respective substrates and then mounted on a Rogers
RT/duroid 5880 laminate. Ground planes are used on both the
front and backside of the antenna array. The antenna is operating
in a range of 24.25 GHz - 29.5 GHz. A Smart Array is proposed
in this paper which has a good performance in terms of antenna
gain and scanning property for 5G application in Smart
handovers.This work was partly funded by the Ministerio de Ciencia e
Innovacion (MICINN) under projects TEC2016-78028-C3-1-
P, PID 2019-107885GB-C31, MDM2016-0600, and Catalan
Research Group 2017 SGR 219.Bharath Reddy, G.; Ramirez, GA.; Molins-Benlliure, J.; Ferrando Bataller, M.; Romeu, J.; Jofre-R., L. (2020). Vehicular mm-Wave Array for Smart Handover. Universidad de Málaga. 1-4. http://hdl.handle.net/10251/178564S1
Private Financing or Not, That is the Question: Lessons from the Light Rail Systems in Spain
The objective of this paper is to analyze if there
is any difference between the light rail systems in Spain
according to whether they have been carried out through
public financing or private financing (totally or partially).
The importance of this study lies in the fact that, for decades,
the public–private partnership has been proposed as
an alternative to public financing of public transport projects
in order to obtain additional financial resources,
reduce the public deficit, and increase efficiency. However,
there are hardly any detailed studies describing how these
initiatives have turned out. Therefore, the present study
analyzes if there is any difference in the main variables
explaining the performance of light rail projects in Spain
depending on their source of funding can be found. For
this, the relationship between variables related to design,
operation and costs of the projects, and the percentage of
private financing were statistically analyzed. As the most
relevant conclusion, we underline the fact that the investment
per passenger increases when financing is completely
private. This would indicate that the most cost-effective
lines, from a social standpoint, were financed totally or
partially by the public administrations, whereas the least
beneficial ones for society were assigned to private enterprises.
This finding provides an advance in the knowledge
of the consequences of private participation in the financing
of public transport projects, indicating, moreover, that
the biggest beneficiaries of this type of projects might be
the construction companies and the politicians involvedThe authors would like to thank the ERDF of
European Union for financial support via project ‘‘Herramienta para
la evaluacio´n previa de infraestructuras de transporte pu´blico’’
(GGI3003IDIE). We also thank to Public Works Agency and
Regional Ministry of Public Works and Housing of the Regional
Government of Andalusia (AOPJA) and the Ministry of Education,
Culture and Sports of the Government of Spain
Three dimensional microfabricated broadband patch and multifunction reconfigurable antennae for 60 GHz applications
In this paper we present two antenna designs capable of covering the IEEE 802.11ad (WiGig) frequency band (57-66 GHz and 59-66 GHz respectively). The work below reports the design, microfabrication and characterization of a broadband patch antenna along with the design and microfabrication of multifunction reconfigurable antenna (MRA) in its static form excluding active switching. The first design is a patch antenna where the energy is coupled with a conductor-backed (CB) coplanar waveguide (CPW)-fed loop slot, resulting in a broad bandwidth. The feed circuitry along with the loop is formed on a quartz substrate (at 60 GHz), on top of which an SU-8-based three-dimensional (3D) structure with air cavities is microfabricated. The patch metallization is deposited on top of this structure. The second design is a CB CPW-fed loop slot coupled patch antenna with a parasitic layer on top. The feed circuitry along with the loop is formed on a quartz substrate. On top, the patch metallization is patterned on another quartz substrate. The parasitic pixels are deposited on top of these two quartz layers on top of an SU-8 based 3D structure with air cavities. © 2015 EurAAP
Three-dimensional microfabricated broadband patch antenna for wigig applications
The design, microfabrication, and characterization of a broadband patch antenna capable of covering the entire IEEE 802.11ad (WiGig) frequency band (57-66 GHz) are presented in this letter. A conductor-backed (CB) coplanar waveguide (CPW)-fed loop slot couples the energy to the patch antenna, resulting in a broad bandwidth. The feed circuitry along with the loop is formed on a quartz substrate (\varepsilon-{\rm r} = 3.9, \tan \delta = 0.0002 at 60 GHz), on top of which an SU-8-based three-dimensional (3-D) structure with air cavities is microfabricated. The patch metallization is deposited on top of this 3-D structure. While the main role of the structure made out of SU-8 material is to provide a mechanical support for the patch metallization, the antenna takes advantage of the air cavities underneath, thus resulting in an antenna substrate with a very low loss. This, in turn, improves the overall antenna performances. The simulated and measured impedance characteristics agree well, showing {\sim}15\hbox{\%} bandwidth. Also, the radiation pattern results demonstrate the integrity of radiation pattern with reasonably constant gain values (average {\sim}6.4~dB) in the broadside direction over the entire WiGig band. © 2002-2011 IEEE
Judicial disagreement need not be political: dissent on the Estonian Supreme Court
I investigate the non-unanimous decisions of judges on the Estonian Supreme Court. I argue that since judges on the court enjoy high de jure independence, dissent frequently, and are integrated in the normal judicial hierarchy, the Estonian Supreme Court is a crucial case for the presumption that judicial disagreement reveals policy preferences. I analyse dissenting opinions using an ideal point response model. Examining the characteristics of cases which discriminated with respect to the recovered dimension, I show that this dimension cannot be interpreted as a meaningful policy dimension, but instead reflects disagreement about the proper scope of constitutional redress
- …