104 research outputs found
Viability assessment of WPS 2.0 services as communication standard for expensive web-based machine learning analysis. A case of study : Indoor Location
Dissertation submitted in partial fulfilment of the requirements for the degree of Master of Science in Geospatial TechnologiesCommunication between client and server is a key factor in the modern age. Nowadays,
telecommunications are at the base of every system and Software that is available. The
way Software communicates can determine the efficacy of it.
In the GIS world, a server is often used for offloading expensive tasks such as geospatial
operations or statistical analysis. This technique improves the performance of the
Software systems and makes them able to scale based on the demand on real time.
For making the communication between client and server more efficient, interoperable
and standard, the OGC released the standard WPS. WPS defines abstract operations
that are able to describe a client server communication for remote process executions.
This thesis focuses on the asynchronous execution feature introduced in the version
2.0 of WPS. The main goal is to study how asynchronous process execution can benefit
a client both in performance and availability.
The result are promising and it is demonstrated that WPS is a solid standard for
describing web services operations. Based on the obtained results, future studies can
extend the standard in order to make it more general and suitable for more situations
Diseño de una arquitectura para la integración de información semi-estructurada proveniente de páginas web y su mejora con contenido semántico
Treball Final de Grau en Enginyeria Informàtica. Codi: EI1054. Curs acadèmic 2013-2014En este documento se presenta una propuesta de arquitectura Software para el desarrollo
de aplicaciones Web de extracción, transformación y distribución de información a partir de
páginasWeb. En el proceso de transformación de los datos, éstos se amplían añadiendo contenido
semántico (meta-datos). La información ampliada se distribuye en formato XML. La arquitectura
propuesta se compone de módulos para la realización de las tareas necesarias.
Con n demostrativo, se han creado dos aplicaciones Web, una para servir la información
de los trenes de la Comunidad Valenciana y la otra para proporcionar información acerca del
servicio de préstamo de bicis en Castellón Bicicas. Finalmente, se ha desarrollado un tercer
proyecto para la integración de los dos anteriores en una aplicación Web para la plani cación de
rutas de transporte intermodales
Design and construction of a distributed sensor NET for biotelemetric monitoring of brain energetic metabolism using microsensors and biosensors
Neurochemical pathways involved in brain physiology or disease pathogenesis are mostly
unknown either in physiological conditions or in neurodegenerative diseases. Nowadays
the most frequent usage for biotelemetry is in medicine, in cardiac care units or step-down
units in hospitals, even if virtually any physiological signal could be transmitted (FCC, 2000;
Leuher, 1983; Zhou et al., 2002). In this chapter we present a wireless device connected with
microsensors and biosensors capable to detect real-time variations in concentrations of
important compounds present in central nervous system (CNS) and implicated in brain
energetic metabolism (Bazzu et al., 2009; Calia et al., 2009)
Chemically modified β-cyclodextrins useful in developing biosensors of agricultural and food relevance
β-cyclodextrin (β-CD), a natural, non-toxic cycloeptaamilose macrocycle, is a useful biomatrix for immobilizing enzymes on a biosensor surface because of the affinity of its cavity for hydrophobic guest molecules (e.g., aminoacids). In this work β-CD has been successfully modified with different poly-carboxylic acids (PCAs) including 1,2,3,4-butanetetracarboxylic acid. Time activation, pH, pressure and stoichiometry were optimized in order to achieve selected substitutions on the
macrocycle hydroxy groups. The modified β-CDs, prepared under mild conditions, are completely water-soluble and could be grafted on a biosensor surface
Velocity Saturation effect on Low Frequency Noise in short channel Single Layer Graphene FETs
Graphene devices for analog and RF applications are prone to Low Frequency
Noise (LFN) due to its upconversion to undesired phase noise at higher
frequencies. Such applications demand the use of short channel graphene
transistors that operate at high electric fields in order to ensure a high
speed. Electric field is inversely proportional to device length and
proportional to channel potential so it gets maximized as the drain voltage
increases and the transistor length shrinks. Under these conditions though,
short channel effects like Velocity Saturation (VS) should be taken into
account. Carrier number and mobility fluctuations have been proved to be the
main sources that generate LFN in graphene devices. While their contribution to
the bias dependence of LFN in long channels has been thoroughly investigated,
the way in which VS phenomenon affects LFN in short channel devices under high
drain voltage conditions has not been well understood. At low electric field
operation, VS effect is negligible since carriers velocity is far away from
being saturated. Under these conditions, LFN can be precicely predicted by a
recently established physics-based analytical model. The present paper goes a
step furher and proposes a new model which deals with the contribution of VS
effect on LFN under high electric field conditions. The implemented model is
validated with novel experimental data, published for the first time, from CVD
grown back-gated single layer graphene transistors operating at gigahertz
frequencies. The model accurately captures the reduction of LFN especially near
charge neutrality point because of the effect of VS mechanism. Moreover, an
analytical expression for the effect of contact resistance on LFN is derived.
This contact resistance contribution is experimentally shown to be dominant at
higher gate voltages and is accurately described by the proposed model.Comment: Main Manuscript:10 pages, 6 figure
Understanding the Bias Dependence of Low Frequency Noise in Sin-gle Layer Graphene FETs
This letter investigates the bias-dependent low frequency noise of single
layer graphene field-effect transistors. Noise measurements have been conducted
with electrolyte-gated graphene transistors covering a wide range of gate and
drain bias conditions for different channel lengths. A new analytical model
that accounts for the propagation of the local noise sources in the channel to
the terminal currents and voltages is proposed in this paper to investigate the
noise bias dependence. Carrier number and mobility fluctuations are considered
as the main causes of low frequency noise and the way these mechanisms
contribute to the bias dependence of the noise is analyzed in this work.
Typically, normalized low frequency noise in graphene devices has been usually
shown to follow an M-shape dependence versus gate voltage with the minimum near
the charge neutrality point (CNP). Our work reveals for the first time the
strong correlation between this gate dependence and the residual charge which
is relevant in the vicinity of this specific bias point. We discuss how charge
inhomogeneity in the graphene channel at higher drain voltages can contribute
to low frequency noise; thus, channel regions nearby the source and drain
terminals are found to dominate the total noise for gate biases close to the
CNP. The excellent agreement between the experimental data and the predictions
of the analytical model at all bias conditions confirms that the two
fundamental 1/f noise mechanisms, carrier number and mobility fluctuations,
must be considered simultaneously to properly understand the low frequency
noise in graphene FETs. The proposed analytical compact model can be easily
implemented and integrated in circuit simulators, which can be of high
importance for graphene based circuits design.Comment: 18 pages, 10 figure
In-home monitoring system based on WiFi fingerprints for ambient assisted living
This paper presents an in-home monitoring system based on WiFi fingerprints for Ambient Assisted Living. WiFi fingerprints are used to continuously locate a patient at the different rooms in her/his home. The experiments performed provide a correctly location rate of 96% in the best case of all studied scenarios. The behavior obtained by location monitoring allows to detect anomalous behavior such as long stays in rooms out of the common schedule. The main characteristics of the presented system are: a) it is robust enough to work without an own WiFi access point, which in turn means a very affordable solution; b) low obtrusiveness, as it is based on the use of a mobile phone; c) highly interoperable with other wireless connections (bluetooth, RFID) present in current mobile phones; d) alarms are triggered when any anomalous behavior is detected
Deployment of an open sensorized platform in a smart city context
The race to achieve smart cities is producing a continuous effort to adapt new developments and knowledge, for administrations and citizens. Information and Communications Technology are called on to be one of the key players to get these cities to use smart devices and sensors (Internet of Things) to know at every moment what is happening within the city, in order to make decisions that will improve the management of resources.
The proliferation of these “smart things” is producing significant deployment of networks in the city context. Most of these devices are proprietary solutions, which do not offer free access to the data they provide. Therefore, this prevents the interoperability and compatibility of these solutions in the current smart city developments.
This paper presents how to embed an open sensorized platform for both hardware and software in the context of a smart city, more specifically in a university campus. For this integration, GIScience comes into play, where it offers different open standards that allow full control over “smart things” as an agile and interoperable way to achieve this. To test our system, we have deployed a network of different sensorized platforms inside the university campus, in order to monitor environmental phenomena
Green infrastructure planning based on ecosystem services multicriteria evaluation: the case of the metropolitan wine landscapes of Bordeaux
Excessive anthropogenic activities affect landscape patterns and trigger a decrease of natural capital and the level of quality of life. Green infrastructures (GIs) are commonly accepted by scholars as solutions for restoring degraded areas and providing a variety of ecosystem services (ESs). The other way around, the capacity to deliver ESs can be assumed as a relevant starting point for GIs analysis and planning. The assessment of ESs needs extensive investigation and applications, to provide planners, policy makers, and institutional stakeholders with an adequate evaluation tool. The multi-facet nature of ESs assessment implies the use of complex tools able to consider many concerns. In this regard, multicriteria analysis (MCA) is a very popular tool due to its capacity to intertwine a variety of issues in a rigorous way and to support participatory and transparent decision making in the public domain. In this study, we aim at contributing to the integration of GI design into spatial planning starting from the assessment of the net benefit delivered to local society by a GI in the metropolitan area of Bordeaux (France). We assessed the net benefit by confronting the ESs deliverable by the GI and the cost sustained for its construction and maintenance. We applied an MCA-based method to the selection of the most efficient alternative out of three GI paths. We demonstrate that our method is useful for the assessment of cultural and regulating ESs, comparing the GI design alternatives, and considering the preference model of the stakeholders within GI planning and design
Bias Dependent Variability of Low Frequency Noise in Single Layer Graphene FETs
Low-frequency noise (LFN) variability in graphene transistors (GFETs) is for
the first time researched in this work. LFN from an adequate statistical sample
of long-channel solution-gated single-layer GFETs is measured in a wide range
of operating conditions while a physics-based analytical model is derived that
accounts for the bias dependence of LFN variance with remarkable performance.
It is theoretically proved and experimentally validated that LFN deviations in
GFETs stem from physical mechanisms that generate LFN. Thus, carrier number DN
due to trapping/detrapping process and mobility fluctuations Dm which are the
main causes of LFN, define its variability likewise as its mean value. DN
accounts for an M-shape of normalized LFN variance versus gate bias with a
minimum at the charge neutrality point (CNP) as it was the case for normalized
LFN mean value while Dm contributes only near the CNP for both variance and
mean value. Trap statistical nature is experimentally shown to differ from
classical Poisson distribution at silicon-oxide devices, and this is probably
caused by electrolyte interface in GFETs under study. Overall, GFET technology
development is still in a premature stage which might cause pivotal
inconsistencies affecting the scaling laws in GFETs of the same process
- …