112 research outputs found
Nowcasting an Economic Aggregate with Disaggregate Dynamic Factors: An Application to Portuguese GDP
This paper consists of an empirical study comparing a dynamic factor model approach to estimate the current quarter aggregate GDP with the alternative approach of aggregating the forecasts obtained from specific dynamic factor models for each major expenditure disaggregate. The out-of-sample forecasting performance results suggest that there is no advantage in aggregating the disaggregate forecasts.Forecasting; Dynamic Factor Model; Temporal Disaggregation
Influence of Input/output Operations on Processor Performance
Nowadays, computers are frequently equipped with peripherals that transfer great
amounts of data between them and the system memory using direct memory access
techniques (i.e., digital cameras, high speed networks, . . . ). Those peripherals prevent the
processor from accessing system memory for significant periods of time (i.e., while they
are communicating with system memory in order to send or receive data blocks). In this
paper we study the negative effects that I/O operations from computer peripherals have on
processor performance. With the help of a set of routines (SMPL) used to make discrete
event simulators, we have developed a configurable software that simulates a computer
processor and main memory as well as the I/O scenarios where the periph-erals operate.
This software has been used to analyze the performance of four different processors in four
I/O scenarios: video capture, video capture and playback, high speed network, and serial
transmission
A FPGA Spike-Based Robot Controlled with Neuro-inspired VITE
This paper presents a spike-based control system applied to a fixed
robotic platform. Our aim is to take a step forward to a future complete spikes
processing architecture, from vision to direct motor actuation. This paper covers
the processing and actuation layer over an anthropomorphic robot. In this way,
the processing layer uses the neuro-inspired VITE algorithm, for reaching a target,
based on PFM taking advantage of spike system information: its frequency.
Thus, all the blocks of the system are based on spikes. Each layer is implemented
within a FPGA board and spikes communication is codified under the
AER protocol. The results show an accurate behavior of the robotic platform
with 6-bit resolution for a 130º range per joint, and an automatic speed control
of the algorithm. Up to 96 motor controllers could be integrated in the same
FPGA, allowing the positioning and object grasping by more complex anthropomorphic
robots.Ministerio de Ciencia e Innovación TEC2009-10639-C04-02Ministerio de Economía y Competitividad TEC2012-37868-C04-0
Experimental and numerical study of balcony effect in external fire spread into upper floors
In this paper are presented the results of natural fire tests and numerical simulations using the Fire Dynamics Simulator (FDS) and analytical simulations using the methods of EN 1991-1.2 (2010). The main goal of the investigation is the validation of the values of fire safety regulations on distance between openings corresponding to successive floors in a façade and the effect of dimensions of balconies in the external fire spread into upper floors. It is intended to quantify and measure the height and width of flames projected through the windows and to measure the indoor and outdoor temperatures. The tests were performed in a compartment that was intended to represent a small office with two opposing openings, a door and a window. The distance between the openings in the successive floors was1.10 m. The test 1 was carried out without any balcony above the opening and tests 2 and 3 had a balcony with different dimensions in length
Reflectance spectroscopy in combination with cluster analysis as tools for identifying the provenance of Neolithic flint artefacts
The authors thank the staff of the Huelva Museum for the facilities
given to access the archaeological flint blades studied in this article.
Likewise, the authors appreciate the suggestions and constructive criticisms
provided by the two reviewers and in particular wish to thank Dr.
Ryan M. Parish for his excellent review and recommendations that have
notably improved the original manuscript. Angela Tate is thanked for
reviewing the English version of the manuscript.The provenance of flint artefacts found in archaeological excavations is very important for archaeologists to
better understand artefact displacement, exchange networks, mobility patterns, prehistoric migrations and
various cultural processes such as commerce, procurement strategies, territorial boundaries, etc. Reflectance
Spectroscopy is an analytical technique that measures the radiation reflected by any type of surface, as it is
sensitive to electronic and vibrational processes, both at the atomic and molecular level, which results in spectral
signatures and absorption bands of the material. In this study the flint material of 16 quarries with evident signs
of having been used to manufacture artefacts during the Neolithic period have been characterized by means of
their spectral signatures and used to identify the origin of 5 flint blades found in a dolmen close to one of the
quarries. The application of cluster analysis to compare the spectral signatures of both the quarries and the
archaeological blades has ruled out one of them as not being sourced from the studied quarries, as well as
assigning a very probable origin to the other four. Interestingly, none of the blades studied have been sourced to
the nearest quarry, as one might presume. The results of this study confirm that reflectance spectroscopy
combined with the multivariate statistical analysis could provide a powerful tool for determining the origin of
flint artefacts which have been deposited in museums and other institutions
Towards AER VITE: building spike gate signal
Neuromorphic engineers aim to mimic the precise and
efficient mechanisms of the nervous system to process
information using spikes from sensors to actuators. There are
many available works that sense and process information in a
spike-based way. But there are still several gaps in the actuation
and motor control field in a spike-based way. Spike-based
Proportional-Integrative-Derivative controllers (PID) are
present in the literature. On the other hand, neuro-inspired
control models as VITE (Vector Integration To End point) and
FLETE (Factorization of muscle Length and muscle Tension)
are also present in the literature. This paper presents another
step toward the spike implementation of those neuro-inspired
models. We present a spike-based ramp multiplier. VITE
algorithm generates the way to achieve a final position targeted
by a mobile robotic arm. The block presented is used as a gate
for the way involved and it also puts the incoming movement on
speed with a variable slope profile. Only spikes for information
representation were used and the process is in real time. The
software simulation based on Simulink and Xilinx System
Generator shows the accurate adjust to the traditional
processing for short time periods and the hardware tests
confirm and extend the previous simulated results for any time.
We have implemented the spikes generator, the ramp multiplier
and the low pass filter into the Virtex-5 FPGA and connected
this with an USB-AER (Address Event Representation) board to
monitor the spikes.Ministerio de Ciencia e Innovación TEC2009-10639-C04-0
Una mirada integral al África Negra. Metodología de análisis, diagnóstico y estrategias para la ordenación del territorio en África Sursahariana
"El objetivo de esta guía es facilitar el enfoque integral del planeamiento para poder planificar y enmarcar las potenciales intervenciones de los distintos actores dentro de las estrategias territoriales definidas para un territorio, considerando todos sus aspectos de manera global y simultánea. Tras la fase de análisis completo y sistemático, que evita que se pasen por alto aspectos
clave del territorio, para las fases de diagnóstico y propuesta se ofrece la rueda como un instrumento gráfico que permite representar y visualizar simultáneamente los problemas, y posteriormente los objetivos y estrategias aplicables a un territorio. En consecuencia, la guía de trabajo está diseñada específicamente para afrontar una serie de cuestiones clave de carácter urgente: La explotación de recursos naturales y su relación con los medios de vida; La vulnerabilidad ante los riesgos naturales y antrópicos; la insostenibilidad territorial y la falta de gestión de la ocupación del suelo (dispersión urbana, informalidad…); El Cambio climático; La Habitabilidad Precaria
Towards a cloud‑based automated surveillance system using wireless technologies
Cloud Computing can bring multiple benefits for Smart Cities. It permits the easy creation of centralized knowledge bases, thus straightforwardly enabling that multiple embedded systems (such as sensor or control devices) can have a collaborative, shared intelligence. In addition to this, thanks to its vast computing power, complex tasks can be done over low-spec devices just by offloading computation to the cloud, with the additional advantage of saving energy. In this work, cloud’s capabilities are exploited to implement and test a cloud-based surveillance system. Using a shared, 3D symbolic world model, different devices have a complete knowledge of all the elements, people and intruders in a certain open area or inside a building. The implementation of a volumetric, 3D, object-oriented, cloud-based world model (including semantic information) is novel as far as we know. Very simple devices (orange Pi) can send RGBD streams (using kinect cameras) to the cloud, where all the processing is distributed and done thanks to its inherent scalability. A proof-of-concept experiment is done in this paper in a testing lab with multiple cameras connected to the cloud with 802.11ac wireless technology. Our results show that this kind of surveillance system is possible currently, and that trends indicate that it can be improved at a short term to produce high performance vigilance system using low-speed devices. In addition, this proof-of-concept claims that many interesting opportunities and challenges arise, for example, when mobile watch robots and fixed cameras would act as a team for carrying out complex collaborative surveillance strategies.Ministerio de Economía y Competitividad TEC2016-77785-PJunta de Andalucía P12-TIC-130
Bromodomain and extraterminal proteins as vovel epigenetic targets for renal diseases
Epigenetic mechanisms, especially DNA methylation and histone modifications, are
dynamic processes that regulate the gene expression transcriptional program in normal
and diseased states. The bromodomain and extraterminal (BET) protein family (BRD2,
BRD3, BRD4, and BRDT) are epigenetic readers that, via bromodomains, regulate gene
transcription by binding to acetylated lysine residues on histones and master transcriptional
factors. Experimental data have demonstrated the involvement of some BET proteins in
many pathological conditions, including tumor development, infections, autoimmunity,
and inflammation. Selective bromodomain inhibitors are epigenetic drugs that block the
interaction between BET proteins and acetylated proteins, thus exerting beneficial effects.
Recent data have described the beneficial effect of BET inhibition on experimental renal
diseases. Emerging evidence underscores the importance of environmental modifications
in the origin of pathological features in chronic kidney diseases (CKD). Several cellular
processes such as oxidation, metabolic disorders, cytokines, inflammation, or accumulated
uremic toxins may induce epigenetic modifications that regulate key processes involved
in renal damage and in other pathological conditions observed in CKD patients. Here, we
review how targeting bromodomains in BET proteins may regulate essential processes
involved in renal diseases and in associated complications found in CKD patients, such
as cardiovascular damage, highlighting the potential of epigenetic therapeutic strategies
against BET proteins for CKD treatment and associated risksThis work was supported by grants from the Instituto de Salud
Carlos III (ISCIII) and Fondos FEDER European Union
(PI17/00119; Red de Investigación Renal REDINREN: RD16/0009
and PI17/01244), Sociedad Española de Nefrología and
“NOVELREN-CM: Enfermedad renal crónica: nuevas Estrategias
para la prevención, Diagnóstico y tratamiento”; B2017/BMD-
3751, Comunidad de Madrid. The “Juan de la Cierva Formacion”
training program of the Ministerio de Economia, Industria y
Competitividad supported the salary of SR-M (FJCI-2016-29050
Potential of injectable dextrin-based hydrogel for biomedical applications
Bone tissue engineering is a very challenging and promising field, which handles with the limitations of bone regenerative capacity and the failure of current orthopedic implants [1].
This work describes the preparation and characterization of an injectable dextrinbased hydrogel (oDex) through dextrin oxidation followed by cross-linking with a dihydrazide [2]. In vitro and in vivo experiments allowed to conclude that this system can carry and stabilize cells, nanogels, Bonelike® granules [3] and other biomolecules.
This is a promising biomaterial due to its biocompatibility, and potential to promote an adequate environment for bone regeneration, which was increased by the combined bioactive molecules. Its injectability allows a minimal invasive surgical procedure with decreased patient morbidity, lower infection risk and reduced scar formation.
Furthermore, an adequate sterilization protocol for this kind of material was
established.
The tight collaboration between University of Minho and Bioskin S.A. company,
envisioning technology transfer and product valorization, has resulted in a published international patent of the product (WO2011070529A2) [4]. Currently, the submission of a request for the authorization for the clinical trials is being planned
- …