93 results on '"Dics"'
Search Results
2. Dics del Port Fòrum [reportatge fotogràfic]
- Author
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Gerència d'Urbanisme, Gri Espinagosa, Josep, Gerència d'Urbanisme, and Gri Espinagosa, Josep
- Subjects
- Port del Fòrum Sant Adrià (Catalunya)
- Published
- 2023
3. Analysis of Functional Connectivity and Oscillatory Power Using DICS: From Raw MEG Data to Group-Level Statistics in Python
- Author
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Marijn van Vliet, Mia Liljeström, Susanna Aro, Riitta Salmelin, and Jan Kujala
- Subjects
DICS ,MEG ,coherence ,brain rhythms ,workflow ,tutorial ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Communication between brain regions is thought to be facilitated by the synchronization of oscillatory activity. Hence, large-scale functional networks within the brain may be estimated by measuring synchronicity between regions. Neurophysiological recordings, such as magnetoencephalography (MEG) and electroencephalography (EEG), provide a direct measure of oscillatory neural activity with millisecond temporal resolution. In this paper, we describe a full data analysis pipeline for functional connectivity analysis based on dynamic imaging of coherent sources (DICS) of MEG data. DICS is a beamforming technique in the frequency-domain that enables the study of the cortical sources of oscillatory activity and synchronization between brain regions. All the analysis steps, starting from the raw MEG data up to publication-ready group-level statistics and visualization, are discussed in depth, including methodological considerations, rules of thumb and tradeoffs. We start by computing cross-spectral density (CSD) matrices using a wavelet approach in several frequency bands (alpha, theta, beta, gamma). We then provide a way to create comparable source spaces across subjects and discuss the cortical mapping of spectral power. For connectivity analysis, we present a canonical computation of coherence that facilitates a stable estimation of all-to-all connectivity. Finally, we use group-level statistics to limit the network to cortical regions for which significant differences between experimental conditions are detected and produce vertex- and parcel-level visualizations of the different brain networks. Code examples using the MNE-Python package are provided at each step, guiding the reader through a complete analysis of the freely available openfMRI ds000117 “familiar vs. unfamiliar vs. scrambled faces” dataset. The goal is to educate both novice and experienced data analysts with the “tricks of the trade” necessary to successfully perform this type of analysis on their own data.
- Published
- 2018
- Full Text
- View/download PDF
4. Time-Frequency Source Estimation from MEG Data
- Author
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Greenblatt, R. E., Ossadtchi, A., Kurelowech, L., Lawson, D., Criado, J., Magjarevic, Ratko, editor, Supek, Selma, editor, and Sušac, Ana, editor
- Published
- 2010
- Full Text
- View/download PDF
5. Analysis of Functional Connectivity and Oscillatory Power Using DICS: From Raw MEG Data to Group-Level Statistics in Python.
- Author
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van Vliet, Marijn, Liljeström, Mia, Aro, Susanna, Salmelin, Riitta, and Kujala, Jan
- Subjects
MAGNETOENCEPHALOGRAPHY ,NEUROPHYSIOLOGY - Abstract
Communication between brain regions is thought to be facilitated by the synchronization of oscillatory activity. Hence, large-scale functional networks within the brain may be estimated by measuring synchronicity between regions. Neurophysiological recordings, such as magnetoencephalography (MEG) and electroencephalography (EEG), provide a direct measure of oscillatory neural activity with millisecond temporal resolution. In this paper, we describe a full data analysis pipeline for functional connectivity analysis based on dynamic imaging of coherent sources (DICS) of MEG data. DICS is a beamforming technique in the frequency-domain that enables the study of the cortical sources of oscillatory activity and synchronization between brain regions. All the analysis steps, starting from the raw MEG data up to publication-ready group-level statistics and visualization, are discussed in depth, including methodological considerations, rules of thumb and tradeoffs. We start by computing cross-spectral density (CSD) matrices using a wavelet approach in several frequency bands (alpha, theta, beta, gamma). We then provide a way to create comparable source spaces across subjects and discuss the cortical mapping of spectral power. For connectivity analysis, we present a canonical computation of coherence that facilitates a stable estimation of all-to-all connectivity. Finally, we use group-level statistics to limit the network to cortical regions for which significant differences between experimental conditions are detected and produce vertex- and parcel-level visualizations of the different brain networks. Code examples using the MNE-Python package are provided at each step, guiding the reader through a complete analysis of the freely available openfMRI ds000117 “familiar vs. unfamiliar vs. scrambled faces” dataset. The goal is to educate both novice and experienced data analysts with the “tricks of the trade” necessary to successfully perform this type of analysis on their own data. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
6. The drawdown phase of dam decommissioning is a hot moment of gaseous carbon emissions from a temperate reservoir
- Author
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Mabano Amani, Daniel von Schiller, Isabel Suárez, Miren Atristain, Arturo Elosegi, Rafael Marcé, Gonzalo García-Baquero, and Biel Obrador
- Subjects
water reservoirs ,carbon dioxide fluxes ,exposed sediment ,reservoir drawdown ,Aquatic Science ,Dics ,Dipòsits d'aigua ,dam removal ,Carbon dioxide ,Dikes (Engineering) ,Water tanks ,Diòxid de carboni ,Water Science and Technology ,ageing dams - Abstract
Dam decommissioning (DD) is a viable management option for thousands of ageing dams. Reservoirs are large carbon sinks, and reservoir drawdown results in important carbon dioxide (CO2) and methane (CH4) emissions. We studied the effects of DD on CO2 and CH4 fluxes from impounded water, exposed sediment, and lotic water before, during, and 3-10 months after drawdown of the Enobieta Reservoir, north Iberian Peninsula. During the study period, impounded water covered 0-100%, exposed sediment 0-96%, and lotic water 0-4% of the total reservoir area (0.14 km(2)). Areal CO2 fluxes in exposed sediment (mean [SE]: 295.65 [74.90] mmol m(-2) d(-1)) and lotic water (188.11 [86.09] mmol m(-2) d(-1)) decreased over time but remained higher than in impounded water (-36.65 [83.40] mmol m(-2) d(-1)). Areal CH4 fluxes did not change over time and were noteworthy only in impounded water (1.82 [1.11] mmol m(-2) d(-1)). Total ecosystem carbon (CO2 + CH4) fluxes (kg CO2-eq d(-1)) were higher during and after than before reservoir drawdown because of higher CO2 fluxes from exposed sediment. The reservoir was a net sink of carbon before reservoir drawdown and became an important emitter of carbon during the first 10 months after reservoir drawdown. Future studies should examine mid- and long-term effects of DD on carbon fluxes, identify the drivers of areal CO2 fluxes from exposed sediment, and incorporate DD in the carbon footprint of reservoirs. This study was funded by the projects Alteration of carbon sinks and sources in shrinking inland waters (Alter-C), the Spanish Ministry of Science, Innovation and Universities (refs: PID2020-114024GB-C31 funded by MCIN/AEI/10.13039/501100011033/) and Effects of the drawdown of Enobieta Reservoir (Navarre) on the biodiversity and functioning of river ecosystems (DESEMBALSE), Foundation BBVA (ref: PI064-17). AM was supported by an FI grant from the Agencia de Gestio d'Ajuts Universitaris i de Recerca (AGAUR) of the Generalitat de Catalunya. DvS and BO acknowledge support through the Consolidated Research Group 2017SGR0976. RM acknowledges support by the Generalitat de Catalunya through the Consolidated Research Group 2017SGR1124, and by the CERCA program. AE and MA support of the Basque Government through the Consolidated Research Group IT951-16. AM got a predoctoral grant by the University of the Basque Country (UPV/EHU). DvS is a Serra Hunter Fellow.
- Published
- 2022
7. Short‐term effects of a large dam decommissioning on biofilm structure and functioning
- Author
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Miren Atristain, Daniel von Schiller, Aitor Larrañaga, and Arturo Elosegi
- Subjects
Ecology ,Transport de sediments ,Dikes (Engineering) ,Sediment transport ,Dics ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation - Abstract
Aging dams and the rising efforts to restore stream ecosystems are increasing the number of dam decommissioning programs. Although dam decommissioning aims at improving in-stream habitat, biodiversity, and ecosystem functioning in the long term, it might also cause ecological impacts in the short term due to the mobilization of the sediment accumulated in the reservoir. Benthic biofilm in particular can be impaired by episodes of high turbidity and scouring. We conducted a multiple before-after/control-impact experiment to assess the effects of the drawdown of a large dam (42 m tall), a first step to its decommissioning, on biofilm structure (biomass and chlorophyll-a) and functioning (metabolism, nutrient uptake, and organic matter breakdown). Our results show that the reservoir drawdown reduced the autotrophic biofilm biomass (chlorophyll-a) downstream from the dam, which in turn lowered metabolism. However, nitrogen and phosphorus uptake by the biofilm was not affected. Organic matter breakdown was slower below the dam than in nearby undammed reaches before and during drawdown. All drawdown effects quickly disappeared and reaches downstream from the dam approached values found in nearby undammed reaches. Thus, our results indicate that the effects of reservoir drawdown on stream biofilms exist but may be small and disappear rapidly. This research was supported by the Fundación BBVA (064-17). The authors also acknowledge the financial support from the Basque Government (Consolidated Research Group: Stream Ecology 7-CA-18/10) predoctoral fellowships from the University of the Basque Country UPV/EHU (M.A.). The authors are especially grateful to the municipality of Donostia-San Sebastian and the staff of Artikutza for their continuous support during the experiment.
- Published
- 2022
- Full Text
- View/download PDF
8. The differentiated networks related to essential tremor onset and its amplitude modulation after alcohol intake.
- Author
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Pedrosa, David J., Nelles, Christian, Brown, Peter, Volz, Lukas J., Pelzer, Esther A., Tittgemeyer, Marc, Brittain, John-Stuart, and Timmermann, Lars
- Subjects
- *
ESSENTIAL tremor , *ALCOHOL drinking , *BIOLOGICAL rhythms , *SENSORIMOTOR cortex , *CEREBELLAR tumors - Abstract
The dysregulation of endogenous rhythms within brain networks have been implicated in a broad range of motor and non-motor pathologies. Essential tremor (ET), classically the purview of a single aberrant pacemaker, has recently become associated with network-level dysfunction across multiple brain regions. Specifically, it has been suggested that motor cortex constitutes an important node in a tremor-generating network involving the cerebellum. Yet the mechanisms by which these regions relate to tremor remain a matter of considerable debate. We sought to discriminate the contributions of cerebral and cerebellar dysregulation by combining high-density electroencephalography with subject-specific structural MRI. For that, we contrasted ET with voluntary (mimicked) tremor before and after ingestion of alcohol to regulate the tremorgenic networks. Our results demonstrate distinct loci of cortical tremor coherence, most pronounced over the sensorimotor cortices in healthy controls, but more frontal motor areas in ET-patients consistent with a heightened involvement of the supplementary motor area. We further demonstrate that the reduction in tremor amplitude associated with alcohol intake is reflected in altered cerebellar – but not cerebral – coupling with movement. Taken together, these findings implicate tremor emergence as principally associated with increases in activity within frontal motor regions, whereas modulation of the amplitude of established tremor relates to changes in cerebellar activity. These findings progress a mechanistic understanding of ET and implicate network-level vulnerabilities in the rhythmic nature of communication throughout the brain. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
9. Neuronal networks in epileptic encephalopathies with CSWS.
- Author
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Japaridze, Natia, Muthuraman, Muthuraman, Dierck, Carina, Spiczak, Sarah, Boor, Rainer, Mideksa, Kidist G., Anwar, Rauf A., Deuschl, Günther, Stephani, Ulrich, and Siniatchkin, Michael
- Subjects
- *
SLOW wave sleep , *ACTION potentials , *HIGH dynamic range imaging , *SOURCES of coherent radiation , *ETIOLOGY of diseases , *SOMATOSENSORY disorders - Abstract
Objective The aim of our study was to investigate the neuronal networks underlying background oscillations of epileptic encephalopathy with continuous spikes and waves during slow sleep (CSWS). Methods Sleep electroencephalography ( EEG) studies before and after the treatment were investigated in 15 patients with CSWS. To investigate functional and effective connectivity within the network generating the delta activity in the background sleep EEG, the methods of dynamic imaging of coherent sources ( DICS) and renormalized partial directed coherence ( RPDC) were applied. Results Independent of etiology and severity of epilepsy, background EEG pattern in patients with CSWS before treatment is associated with the complex network of coherent sources in medial prefrontal cortex, somatosensory association cortex/posterior cingulate cortex, medial prefrontal cortex, middle temporal gyrus/parahippocampal gyrus/insular cortex, thalamus, and cerebellum. The analysis of information flow within this network revealed that the medial parietal cortex, the precuneus, and the thalamus act as central hubs, driving the information flow to other areas, especially to the temporal and frontal cortex. The described CSWS-specific pattern was no longer observed in patients with normalized sleep EEG. In addition, frequency of spiking showed a strong linear correlations with absolute source power, source coherence strength, and source RPDC strength at both time points: (1) Spike and wave index (SWI) versus absolute source power at EEG1 (r = 0.56; p = 0.008) and at EEG2 (r = 0.45; p = 0.009); (2) SWI versus source coherence strength at EEG1 (r = 0.71; p = 0.005) and at EEG2 (r = 0.52; p = 0.006); and (3) SWI versus source RPDC strength at EEG1 (r = 0.65; p = 0.003) and at EEG2 (r = 0.47; p = 0.009). Significance The leading role of the precuneus and thalamus in the hierarchical organization of the network underlying the background EEG points toward the significance of fluctuations of vigilance in the generation of CSWS. This hierarchical network organization appears to be specific for CSWS as it is resolved after successful treatment. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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10. Cancer et immunodéficiences: Développement d’immunothérapies par transfert adoptif
- Author
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Riviere, Anaïs, Institut de Génétique Moléculaire de Montpellier (IGMM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), École pratique des hautes études (EPHE), and Université Paris sciences et lettres (PSL)
- Subjects
Immunothérapie ,[SDV]Life Sciences [q-bio] ,Cellules T ,DICS ,Thérapie cellulaire ,Cancer - Abstract
La thérapie cellulaire est aujourd'hui une méthode plus que prometteuse. En effet, déjà utilisée en clinique, elle permet de soigner des personnes notamment atteintes d’immunodéficiences ou de cancers. Cependant, des limitations demeurent concernant l’utilisation de ces approches et c’est pourquoi, au cours de ces 3 années, mes travaux ont porté sur l’optimisation de deux types de thérapie cellulaire : la correction d’immunodéficience génétique en cellules T par ciblage direct du thymus, et l’évaluation de l’impact du conditionnement (radiothérapie versus chimiothérapie) sur le devenir des cellules T dans le contexte de thérapies anti-tumorales.Dans un premier temps, je me suis donc intéressée à l’optimisation du traitement d’immunodéficiences génétiques par transplantation de cellules souches hématopoïétiques (CSH). Dans ce contexte, mon laboratoire d’accueil a précédemment montré, dans un modèle murin d’immunodéficience liée à ZAP-70, que le ciblage direct des CSH dans le thymus permet d’obtenir une reconstitution plus rapide et plus efficace des cellules T à partir de l’injection de moins de cellules. Suite à ces résultats, il était important de caractériser les étapes précoces de la prise de greffe et de différenciation des cellules progénitrices injectées. Nous avons ainsi pu montrer une expansion importante (>200x) des progéniteurs hématopoïétiques directement injectés dans le thymus en 3 semaines. Cette expansion est associée à la différenciation des progéniteurs en cellules T matures selon une cinétique et les stades physiologiques. De manière intéressante, nous avons également observé une restauration rapide de l’environnement thymique ainsi que la différenciation de cellules T régulatrices. Mes travaux ont ainsi permis de mettre en évidence une prise de greffe efficace et la mise en place rapide d’une thymopoïèse optimale après ciblage de progéniteurs hématopoïétiques dans le thymus. En parallèle, je me suis intéressée à un projet visant à optimiser les immunothérapies anti-cancer par transfert adoptif de cellules T. L’immunothérapie par transfert adoptif de cellules T représente une approche innovante particulièrement prometteuse qui s’appuie sur l’injection de cellules T autologues spécifiques d’antigènes tumoraux, préalablement manipulées et amplifiées ex vivo, chez des patients rendus lymphopéniques par chimiothérapie et/ou radiothérapie. Toutefois, même si l’état lymphopénique est induit par ces 2 protocoles de conditionnements, leurs effets sur l’environnement de l’hôte ainsi que sur le devenir des cellules T greffées sont mal connus. Par le biais de modèles murins, nous avons pu démontrer que le devenir des cellules T diffère après transfert dans des souris irradiées ou traitées par chimiothérapie Busulfan®/ Cyclophosphamide® (Bu/Cy). Ainsi, après transfert dans des animaux irradiés, on observe une prolifération préférentielle des cellules T CD8, alors qu’un transfert chez des souris traitées Bu/Cy se traduit par une prolifération rapide des cellules T CD4. De plus, ces comportements sont associés à différents phénotypes et notamment un pourcentage élevé des cellules T régulatrices dans les souris Bu/Cy. L’ensemble de ces travaux montrent que les traitements lymphopéniques génèrent des environnements distincts capables de moduler le devenir des cellules T greffées.
- Published
- 2021
11. Task-Modulated Corticocortical Synchrony in the Cognitive-Motor Network Supporting Handwriting
- Author
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Antti Jalava, Timo Saarinen, Jan Kujala, Hannu Laaksonen, Riitta Salmelin, Department of Neuroscience and Biomedical Engineering, Aalto-yliopisto, and Aalto University
- Subjects
Adult ,Male ,Handwriting ,Computer science ,Movement ,Cognitive Neuroscience ,DICS ,Memorization ,Task (project management) ,Young Adult ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Cognition ,0302 clinical medicine ,medicine ,Humans ,motoriikka ,030304 developmental biology ,Brain Mapping ,0303 health sciences ,MEG ,Language production ,medicine.diagnostic_test ,Working memory ,functional connectivity ,movement sequence ,Motor Cortex ,Brain ,Magnetoencephalography ,Hand ,kognitiiviset prosessit ,Phase synchronization ,aivokuori ,Original Article ,Female ,Nerve Net ,Neuroscience ,Psychomotor Performance ,030217 neurology & neurosurgery ,kirjoittaminen ,language production - Abstract
Both motor and cognitive aspects of behavior depend on dynamic, accurately timed neural processes in large-scale brain networks. Here, we studied synchronous interplay between cortical regions during production of cognitive-motor sequences in humans. Specifically, variants of handwriting that differed in motor variability, linguistic content, and memorization of movement cues were contrasted to unveil functional sensitivity of corticocortical connections. Data-driven magnetoencephalography mapping (n = 10) uncovered modulation of mostly left-hemispheric corticocortical interactions, as quantified by relative changes in phase synchronization. At low frequencies (~2–13 Hz), enhanced frontoparietal synchrony was related to regular handwriting, whereas premotor cortical regions synchronized for simple loop production and temporo-occipital areas for a writing task substituting normal script with loop patterns. At the beta-to-gamma band (~13–45 Hz), enhanced synchrony was observed for regular handwriting in the central and frontoparietal regions, including connections between the sensorimotor and supplementary motor cortices and between the parietal and dorsal premotor/precentral cortices. Interpreted within a modular framework, these modulations of synchrony mainly highlighted interactions of the putative pericentral subsystem of hand coordination and the frontoparietal subsystem mediating working memory operations. As part of cortical dynamics, interregional phase synchrony varies depending on task demands in production of cognitive-motor sequences.
- Published
- 2020
12. Representation and propagation of epileptic activity in absences and generalized photoparoxysmal responses.
- Author
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Moeller, Friederike, Muthuraman, Muthuraman, Stephani, Ulrich, Deuschl, Günther, Raethjen, Jan, and Siniatchkin, Michael
- Abstract
Although functional imaging studies described networks associated with generalized epileptic activity, propagation patterns within these networks are not clear. In this study, electroencephalogram (EEG)-based coherent source imaging dynamic imaging of coherent sources (DICS) was applied to different types of generalized epileptiform discharges, namely absence seizures (10 patients) and photoparoxysmal responses (PPR) (eight patients) to describe the representation and propagation of these discharges in the brain. The results of electrical source imaging were compared to EEG-functional magnetic resonance imaging (fMRI) which had been obtained from the same data sets of simultaneous EEG and fMRI recordings. Similar networks were described by DICS and fMRI: (1) absence seizures were associated with thalamic involvement in all patients. Concordant results were also found for brain areas of the default mode network and the occipital cortex. (2) Both DICS and fMRI identified the occipital, parietal, and the frontal cortex in a network associated with PPR. (3) However, only when PPR preceded a generalized tonic-clonic seizure, the thalamus was involved in the generation of PPR as shown by both imaging techniques. Partial directed coherence suggested that during absences, the thalamus acts as a pacemaker while PPR could be explained by a cortical propagation from the occipital cortex via the parietal cortex to the frontal cortex. In conclusion, the electrical source imaging is not only able to describe similar neuronal networks as revealed by fMRI, including deep sources of neuronal activity such as the thalamus, but also demonstrates interactions interactions within these networks and sheds light on pathogenetic mechanisms of absence seizures and PPR. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
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13. Neuronal Networks in West Syndrome as Revealed by Source Analysis and Renormalized Partial Directed Coherence.
- Author
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Japaridze, Natia, Muthuraman, Muthuraman, Moeller, Friederike, Boor, Rainer, Anwar, Abdul, Deuschl, Günther, Stephani, Urlich, Raethjen, Jan, and Siniatchkin, Michael
- Abstract
West syndrome is a severe epileptic encephalopathy of infancy with a poor developmental outcome. This syndrome is associated with the pathognomonic EEG feature of hypsarrhythmia. The aim of the study was to describe neuronal networks underlying hypsarrhythmia using the source analysis method (dynamic imaging of coherent sources or DICS) which represents an inverse solution algorithm in the frequency domain. In order to investigate the interaction within the detected network, a renormalized partial directed coherence (RPDC) method was also applied as a measure of the directionality of information flow between the source signals. Both DICS and RPDC were performed for EEG delta activity (1-4 Hz) in eight patients with West syndrome and in eight patients with partial epilepsies (control group). The brain area with the strongest power in the given frequency range was defined as the reference region. The coherence between this reference region and the entire brain was computed using DICS. After that, the RPDC was applied to the source signals estimated by DICS. The results of electrical source imaging were compared to results of a previous EEG-fMRI study which had been carried out using the same cohort of patients. As revealed by DICS, delta activity in hypsarrhythmia was associated with coherent sources in the occipital cortex (main source) as well as the parietal cortex, putamen, caudate nucleus and brainstem. In patients with partial epilepsies, delta activity could be attributed to sources in the occipital, parietal and sensory-motor cortex. In West syndrome, RPDC showed the strongest and most significant direction of ascending information flow from the brainstem towards the putamen and cerebral cortex. The neuronal network underlying hypsarrhythmia in this study resembles the network which was described in previous EEG-fMRI and PET studies with involvement of the brainstem, putamen and cortical regions in the generation of hypsarrhythmia. The RPDC suggests that brainstem could have a key role in the pathogenesis of West syndrome. This study supports the theory that hypsarrhythmia results from ascending brainstem pathways that project widely to basal ganglia and cerebral cortex. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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14. Oscillatory coupling in writing and writer’s cramp
- Author
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Butz, Markus, Timmermann, Lars, Gross, Joachim, Pollok, Bettina, Dirks, Martin, Hefter, Harald, and Schnitzler, Alfons
- Subjects
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BRAIN , *NEUROLOGICAL disorders , *ELECTRODIAGNOSIS , *PATHOLOGICAL physiology - Abstract
Abstract: Writing is a highly skilled and overlearned movement. In patients suffering from writer’s cramp, a focal task-induced dystonia, writing is impaired or even impossible due to involuntary muscle contractions and abnormal posture, which occur as soon as the person picks up a pen or within writing a few words. The underlying pathophysiological mechanisms of this movement disorder are not fully understood up to now. The aim of the present study was to unravel the oscillatory network underlying physiological writing in healthy subjects and dystonic writing in writer’s cramp patients. Using whole-head magnetoencephalography (MEG) and the analysis tool dynamic imaging of coherent sources (DICS) we studied oscillatory neural coupling during writing in eleven healthy subjects and eight patients suffering from writer’s cramp. Simultaneous recording of brain activity with MEG and activity of forearm and hand muscles with surface electromyography (EMG) was performed while subjects were writing for five minutes with their dominant right hand. Applying DICS sources of strongest cerebro-muscular coherence and cerebro-cerebral coherence during writing were identified, which consistently included six brain areas in both, the control subjects and the patients: contralateral and ipsilateral sensorimotor cortex, ipsilateral cerebellum, contralateral thalamus, contralateral premotor and posterior parietal cortex. Coherence between cortical sources and muscles appeared primarily in the frequency of writing movements (3–7Hz) while coherence between cerebral sources occurred primarily around 10Hz (8–13Hz). Interestingly, consistent coupling between both sensorimotor cortices was observed in patients only, whereas coupling between ipsilateral cerebellum and the contralateral posterior parietal cortex was found in control subjects only. These results are consistent with the often described bilateral pathophysiology and impaired sensorimotor integration in writer’s cramp patients. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
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15. Physiological and pathological oscillatory networks in the human motor system
- Author
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Schnitzler, Alfons, Timmermann, Lars, and Gross, Joachim
- Subjects
- *
BRAIN , *MOTOR ability , *PATHOLOGICAL physiology , *TOXIC psychoses - Abstract
Abstract: Human brain functions are heavily contingent on neural interactions both at the single neuron and the neural population or system level. Accumulating evidence from neurophysiological studies strongly suggests that coupling of oscillatory neural activity provides an important mechanism to establish neural interactions. With the availability of whole-head magnetoencephalography (MEG) macroscopic oscillatory activity can be measured non-invasively from the human brain with high temporal and spatial resolution. To localise, quantify and map oscillatory activity and interactions onto individual brain anatomy we have developed the ‘dynamic imaging of coherent sources’ (DICS) method which allows to identify and analyse cerebral oscillatory networks from MEG recordings. Using this approach we have characterized physiological and pathological oscillatory networks in the human sensorimotor system. Coherent 8Hz oscillations emerge from a cerebello-thalamo-premotor-motor cortical network and exert an 8Hz oscillatory drive on the spinal motor neurons which can be observed as a physiological tremulousness of the movement termed movement discontinuities. This network represents the neurophysiological substrate of a discrete mode of motor control. In parkinsonian resting tremor we have identified an extensive cerebral network consisting of primary motor and lateral premotor cortex, supplementary motor cortex, thalamus/basal ganglia, posterior parietal cortex and secondary somatosensory cortex, which are entrained in the tremor or twice the tremor rhythm. This low frequency entrapment of motor areas likely plays an important role in the pathophysiology of parkinsonian motor symptoms. Finally, studies on patients with postural tremor in hepatic encephalopathy revealed that this type of tremor results from a pathologically slow thalamocortical and cortico-muscular coupling during isometric hold tasks. In conclusion, the analysis of oscillatory cerebral networks provides new insights into physiological mechanisms of motor control and pathophysiological mechanisms of tremor disorders. [Copyright &y& Elsevier]
- Published
- 2006
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16. Neuromagnetic localization of rhythmic activity in the human brain: a comparison of three methods
- Author
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Liljeström, M., Kujala, J., Jensen, O., and Salmelin, R.
- Subjects
- *
BRAIN , *MAGNETOENCEPHALOGRAPHY , *CEREBRAL cortex , *EVOKED potentials (Electrophysiology) - Abstract
Abstract: Cortical rhythmic activity is increasingly employed for characterizing human brain function. Using MEG, it is possible to localize the generators of these rhythms. Traditionally, the source locations have been estimated using sequential dipole modeling. Recently, two new methods for localizing rhythmic activity have been developed, Dynamic Imaging of Coherent Sources (DICS) and Frequency-Domain Minimum Current Estimation (MCEFD). With new analysis methods emerging, the researcher faces the problem of choosing an appropriate strategy. The aim of this study was to compare the performance and reliability of these three methods. The evaluation was performed using measured data from four healthy subjects, as well as with simulations of rhythmic activity. We found that the methods gave comparable results, and that all three approaches localized the principal sources of oscillatory activity very well. Dipole modeling is a very powerful tool once appropriate subsets of sensors have been selected. MCEFD provides simultaneous localization of sources and was found to give a good overview of the data. With DICS, it was possible to separate close-by sources that were not retrieved by the other two methods. [Copyright &y& Elsevier]
- Published
- 2005
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17. Properties of MEG tomographic maps obtained with spatial filtering
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Gross, J., Timmermann, L., Kujala, J., Salmelin, R., and Schnitzler, A.
- Subjects
- *
MAGNETOENCEPHALOGRAPHY , *DIAGNOSTIC imaging , *BRAIN - Abstract
Magnetoencephalography (MEG) has, in comparison with other functional imaging modalities, unique properties which makes it the prime candidate for the noninvasive investigation of long-range oscillatory interactions in the human brain. Recent methodological developments based on spatial filtering introduced the computation of functional tomographic maps covering the entire brain and representing the distribution of coherence to a given reference signal or the distribution of power. Because of the spatially inhomogeneous sensitivity profile of the MEG sensors, the spatial resolution of the resulting functional maps is not isotropic across the brain. Here, we introduce a convenient analytic expression for the computation of the spatial resolution at any given point in the brain. We derive the dependence of the resolution on the signal-to-noise ratio and on the changes of the leadfields. The resolution map can be displayed on anatomical MRI in the same way as the functional maps. In addition, we establish a procedure for computing a confidence volume of local maxima which is based on a bootstrap method. The confidence volume is a measure for the uncertainty of the localization. It is important for assigning local maxima of activation to specific anatomical structures and may be used to test for differences in localization between different experimental conditions. [Copyright &y& Elsevier]
- Published
- 2003
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18. Proyecto de regeneración y ordenación de la playa de la Garrofera (T.M. Valencia)
- Author
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Serra Peris, José Cristobal, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos - Escola Tècnica Superior d'Enginyers de Camins, Canals i Ports, Lluch García, Jade, Serra Peris, José Cristobal, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos - Escola Tècnica Superior d'Enginyers de Camins, Canals i Ports, and Lluch García, Jade
- Abstract
[ES] La playa de la Garrofera, situada en Valencia, en el entorno del Parque Natural de l'Albufera, se encuentra en continua regresión debido a la falta de aportes sedimentarios que recibe, y es que el Puerto de Valencia, situado al norte de la misma, actúa como una barrera al transporte sólido litoral, esto sumado al encauzamiento de los ríos Júcar y Turia , hace que la playa no reciba suficientes aportes, reduciéndose el ancho de la misma, haciéndola vulnerable frente a los temporales, acabando con las reservas dunares y poniendo en peligro las edificaciones próximas. Tras estudiar las posibles soluciones, se plantea la construcción de cinco diques exentos a nivel medio del mar de ciento veinte metros de largo, que protejan la costa del oleaje incidente y ayuden a la acumulación de sedimentos. Además, esta actuación se desarrollará de forma conjunta con la aportación artificial de 800.000m3 de arena procedente del fondo marino. Por otra parte, se realizará una regeneración dunar en las zonas que se encuentran afectadas, ya sea por los temporales o por la acción antrópica, revegetando para favorecer la retención de sedimentos., [CA] La platja de la Garrofera, situada a València, a l'entorn del Parc Natural de l'Albufera, es troba en contínua regressió a causa de la falta d'aportacions sedimentàries que rep, i és que el Port de València, situat al nord d'aquesta, actua com una barrera al transport sòlid litoral, això sumat a la canalització dels rius Xúquer i Túria , fa que la platja no reba suficients aportacions, reduint-se l'ample d'aquesta, fent-la vulnerable enfront dels temporals, acabant amb les reserves dunares i posant en perill les edificacions pròximes. Després d'estudiar les possibles solucions, es planteja la construcció de cinc dics exempts a nivell mitjà del mar, de cent vint metres de llarg, que protegisquen la costa de l'onatge incident i ajuden l'acumulació de sediments. A més, aquesta actuació es desenvoluparà de forma conjunta amb l'aportació artificial de 800.000m3 d'arena procedent del fons marí. D'altra banda, es realitzarà una regeneració dunar en les zones que es troben afectades, ja siga pels temporals o per l'acció antròpica, revegetant per a afavorir la retenció de sediments., [EN] The Garrofera beach, located in Valencia, in the surroundings of the Albufera Natural Park, is in continuous regression due to the lack of sedimentary contributions it receives. The Port of Valencia, located to the north of the beach, acts as a barrier to solid coastal transport, this added to the channelling of the Júcar and Turia rivers, makes the beach not receive enough contributions, reducing its width, making it vulnerable to storms, destroying the dune reserves and endangering the nearby buildings, making it vulnerable to storms, destroying the dune reserves and endangering the nearby buildings. After studying the possible solutions, the construction of five exempt dikes at mean sea level of one hundred and twenty meters long is proposed, which protect the coast from the incident waves and help the accumulation of sediments. In addition, this action will be developed jointly with the artificial contribution of 800,000m3 of sand from the seabed. On the other hand, a dune regeneration will be carried out in the areas that are affected, either by storms or by anthropogenic action, revegetating to favour the retention of sediments.
- Published
- 2019
19. Estudio para la regeneración del frente litoral de la playa de Nules (Castellón)
- Author
-
Molines Llodra, Jorge, Universitat Politècnica de València. Departamento de Ingeniería e Infraestructura de los Transportes - Departament d'Enginyeria i Infraestructura dels Transports, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos - Escola Tècnica Superior d'Enginyers de Camins, Canals i Ports, Universitat Politècnica de València. Instituto del Transporte y Territorio - Institut del Transport i Territori, Balaguer Canet, Javier, Molines Llodra, Jorge, Universitat Politècnica de València. Departamento de Ingeniería e Infraestructura de los Transportes - Departament d'Enginyeria i Infraestructura dels Transports, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos - Escola Tècnica Superior d'Enginyers de Camins, Canals i Ports, Universitat Politècnica de València. Instituto del Transporte y Territorio - Institut del Transport i Territori, and Balaguer Canet, Javier
- Abstract
[EN] This work consists, first of all, in a brief study of the current problems faced by the coastline of the Nules beach, such as the progressive erosion suffered by the beach due to the coastal dynamics, where just the beach location is harmed by Barriers to solid coastal transport such as the port of Burriana, another problem is the strong pressure on the beach exerted by the houses that are found, and then a proposal for its solution. This proposal is studied and analyzed with a study of solutions that will try to choose the best option of action to solve the problem previously raised. Four alternatives are studied to choose the best according to a multicriteria score based on the criteria: functional, economic, environmental and landscape. In the end, one chooses to act according to alternative 1, which proposes a construction of 4 breakwaters exempt to create 4 places in the beach, in the southern part of the mouth of the Nules lake, next to a retreat of transverse peaks , and an artificial feeding; And in the northern part will only proceed to artificial feeding. Once the best option is chosen, it is calculated in detail what it takes to calculate the wave height to calculate the weight of the breakwater that will form the exemption dams. With this and a characterization of the existing breakwater on the beach that will be dismantled, it is arrived at that it is possible to re-use the breakwater of these breakwaters to be removed and used in the new exemption dams. The procedure that will be followed to build these dams is by land without the need forr special machinery. Once the dams and their hemithograms have been calculated, it is possible to complete some profiles on the beach that will characterize the new beach form and will be used to cover the volume to provide sand on the beach of Nules. The material for this artificial feeding will be requested in quarry, and will have a Dn50 very similar to the existing one. This part will be the most expensive, r, [CA] Este trabajo consiste en, primero un breve estudio de la problemática actual que sufre el frente litoral de la playa de Nules, como la erosión progresiva que sufre la playa por la dinámica litoral, donde justo el emplazamiento de la playa se ve perjudicado por barreras del transporte sólido litoral como el puerto de Burriana, otra problemática es la fuerte presión en el escarpe de la playa ejercida por las casas que se encuentran, y seguidamente una propuesta para su solución. Esta propuesta es estudiada y analizada con un estudio de soluciones que pretenderá escoger la mejor opción de actuación para resolver el problema anteriormente planteado. Se estudian 4 alternativas para escoger la mejor según una puntuación multicriterio basada en los criterios: funcional, económico, ambiental y paisajístico. En definitiva, se escoge actuar según la alternativa 1, que propone una construcción de 4 diques exentos para crear 4 hemitómbolos en la parte sur de la desembocadura del estanque de Nules, junto a una retirada de espigones transversales, y una alimentación artificial; y en la parte norte solo se procederá a la alimentación artificial. Una vez escogida la mejor opción se calcula detalladamente lo que lleva a calcular la altura de ola para calcular el peso de la escollera que formará los diques exentos. Con esto y una caracterización de los espigones existentes en la playa que se desmantelarán, se llega a que es posible una reutilización de escollera de estos espigones a retirar y se utilizará en los nuevos diques exentos. El procedimiento que se seguirá para construir estos diques es por vía terrestre sin necesidad de protonas ni maquinaria especial. Una vez calculados los diques y sus hemitómbolos, se procede a la realización de unos perfiles en la playa que caracterizarán la nueva forma de playa y serán utilizados para la cubicación del volumen a aportar de arenas en la playa de Nules. El material para esta alimentación artificial se pedirá en cantera, y tendrá un, [ES] Este trabajo consiste en, primero un breve estudio de la problemática actual que sufre el frente litoral de la playa de Nules, como la erosión progresiva que sufre la playa por la dinámica litoral, donde justo el emplazamiento de la playa se ve perjudicado por barreras del transporte sólido litoral como el puerto de Burriana, otra problemática es la fuerte presión en el escarpe de la playa ejercida por las casas que se encuentran, y seguidamente una propuesta para su solución. Esta propuesta es estudiada y analizada con un estudio de soluciones que pretenderá escoger la mejor opción de actuación para resolver el problema anteriormente planteado. Se estudian 4 alternativas para escoger la mejor según una puntuación multicriterio basada en los criterios: funcional, económico, ambiental y paisajístico. En definitiva, se escoge actuar según la alternativa 1, que propone una construcción de 4 diques exentos para crear 4 hemitómbolos en la parte sur de la desembocadura del estanque de Nules, junto a una retirada de espigones transversales, y una alimentación artificial; y en la parte norte solo se procederá a la alimentación artificial. Una vez escogida la mejor opción se calcula detalladamente lo que lleva a calcular la altura de ola para calcular el peso de la escollera que formará los diques exentos. Con esto y una caracterización de los espigones existentes en la playa que se desmantelarán, se llega a que es posible una reutilización de escollera de estos espigones a retirar y se utilizará en los nuevos diques exentos. El procedimiento que se seguirá para construir estos diques es por vía terrestre sin necesidad de protonas ni maquinaria especial. Una vez calculados los diques y sus hemitómbolos, se procede a la realización de unos perfiles en la playa que caracterizarán la nueva forma de playa y serán utilizados para la cubicación del volumen a aportar de arenas en la playa de Nules. El material para esta alimentación artificial se pedirá en cantera, y tendrá un
- Published
- 2019
20. Tecnología blockchain aplicada al empoderamiento de las mujeres
- Author
-
Valero i Geira, Tere and Valero i Geira, Tere
- Abstract
El proyecto nace de la iniciativa de un grupo de profesionales que vemos las dificultades que un gran número de mujeres tiene para acceder a una apropiada educación, información, formación y comunicación cuando éstas desean crear su propio negocio o actividad profesional. Las dificultades pueden ser varias, pero este proyecto se focaliza en solucionar las tecnológicas y dinerarias, con el objetivo de empoderar a las mujeres para que tomen las riendas de su desarrollo personal y profesional sin que la tecnología ni el dinero sean obstáculos. La solución adoptada prioriza un nuevo medio de pago para uso interno de colectivos de mujeres, que pueden ser tan grandes como se quiera. Dicho medio de pago se pretende que aúne las ventajas de las monedas sociales y de la cadena de bloques
- Published
- 2019
21. Proyecto de regeneración y ordenación de la playa de la Garrofera (T.M. Valencia)
- Author
-
Lluch García, Jade
- Subjects
Dunes ,Dune ,Regeneración ,Dunas ,Beach ,Regeneració ,Máster Universitario en Transporte, Territorio y Urbanismo-Màster Universitari en Transport, Territori i Urbanisme ,Playa ,Dics ,INGENIERIA E INFRAESTRUCTURA DE LOS TRANSPORTES ,Platja ,Construcció ,Dikes ,Regeneration ,Construcción ,Diques ,Construction - Abstract
[ES] La playa de la Garrofera, situada en Valencia, en el entorno del Parque Natural de l'Albufera, se encuentra en continua regresión debido a la falta de aportes sedimentarios que recibe, y es que el Puerto de Valencia, situado al norte de la misma, actúa como una barrera al transporte sólido litoral, esto sumado al encauzamiento de los ríos Júcar y Turia , hace que la playa no reciba suficientes aportes, reduciéndose el ancho de la misma, haciéndola vulnerable frente a los temporales, acabando con las reservas dunares y poniendo en peligro las edificaciones próximas. Tras estudiar las posibles soluciones, se plantea la construcción de cinco diques exentos a nivel medio del mar de ciento veinte metros de largo, que protejan la costa del oleaje incidente y ayuden a la acumulación de sedimentos. Además, esta actuación se desarrollará de forma conjunta con la aportación artificial de 800.000m3 de arena procedente del fondo marino. Por otra parte, se realizará una regeneración dunar en las zonas que se encuentran afectadas, ya sea por los temporales o por la acción antrópica, revegetando para favorecer la retención de sedimentos., [CA] La platja de la Garrofera, situada a València, a l'entorn del Parc Natural de l'Albufera, es troba en contínua regressió a causa de la falta d'aportacions sedimentàries que rep, i és que el Port de València, situat al nord d'aquesta, actua com una barrera al transport sòlid litoral, això sumat a la canalització dels rius Xúquer i Túria , fa que la platja no reba suficients aportacions, reduint-se l'ample d'aquesta, fent-la vulnerable enfront dels temporals, acabant amb les reserves dunares i posant en perill les edificacions pròximes. Després d'estudiar les possibles solucions, es planteja la construcció de cinc dics exempts a nivell mitjà del mar, de cent vint metres de llarg, que protegisquen la costa de l'onatge incident i ajuden l'acumulació de sediments. A més, aquesta actuació es desenvoluparà de forma conjunta amb l'aportació artificial de 800.000m3 d'arena procedent del fons marí. D'altra banda, es realitzarà una regeneració dunar en les zones que es troben afectades, ja siga pels temporals o per l'acció antròpica, revegetant per a afavorir la retenció de sediments., [EN] The Garrofera beach, located in Valencia, in the surroundings of the Albufera Natural Park, is in continuous regression due to the lack of sedimentary contributions it receives. The Port of Valencia, located to the north of the beach, acts as a barrier to solid coastal transport, this added to the channelling of the Júcar and Turia rivers, makes the beach not receive enough contributions, reducing its width, making it vulnerable to storms, destroying the dune reserves and endangering the nearby buildings, making it vulnerable to storms, destroying the dune reserves and endangering the nearby buildings. After studying the possible solutions, the construction of five exempt dikes at mean sea level of one hundred and twenty meters long is proposed, which protect the coast from the incident waves and help the accumulation of sediments. In addition, this action will be developed jointly with the artificial contribution of 800,000m3 of sand from the seabed. On the other hand, a dune regeneration will be carried out in the areas that are affected, either by storms or by anthropogenic action, revegetating to favour the retention of sediments.
- Published
- 2019
22. Estudio para la regeneración del frente litoral de la playa de Nules (Castellón)
- Author
-
Balaguer Canet, Javier
- Subjects
Regeneración ,Beach ,Platja ,Regeneració ,Regeneration ,Breakwaters ,Grado en Ingeniería Civil-Grau en Enginyeria Civil ,Nules ,Dics ,Playa ,Diques ,INGENIERIA E INFRAESTRUCTURA DE LOS TRANSPORTES - Abstract
[EN] This work consists, first of all, in a brief study of the current problems faced by the coastline of the Nules beach, such as the progressive erosion suffered by the beach due to the coastal dynamics, where just the beach location is harmed by Barriers to solid coastal transport such as the port of Burriana, another problem is the strong pressure on the beach exerted by the houses that are found, and then a proposal for its solution. This proposal is studied and analyzed with a study of solutions that will try to choose the best option of action to solve the problem previously raised. Four alternatives are studied to choose the best according to a multicriteria score based on the criteria: functional, economic, environmental and landscape. In the end, one chooses to act according to alternative 1, which proposes a construction of 4 breakwaters exempt to create 4 places in the beach, in the southern part of the mouth of the Nules lake, next to a retreat of transverse peaks , and an artificial feeding; And in the northern part will only proceed to artificial feeding. Once the best option is chosen, it is calculated in detail what it takes to calculate the wave height to calculate the weight of the breakwater that will form the exemption dams. With this and a characterization of the existing breakwater on the beach that will be dismantled, it is arrived at that it is possible to re-use the breakwater of these breakwaters to be removed and used in the new exemption dams. The procedure that will be followed to build these dams is by land without the need forr special machinery. Once the dams and their hemithograms have been calculated, it is possible to complete some profiles on the beach that will characterize the new beach form and will be used to cover the volume to provide sand on the beach of Nules. The material for this artificial feeding will be requested in quarry, and will have a Dn50 very similar to the existing one. This part will be the most expensive, referring to the important amount of cubic meters that will be around 700,000, and also referred to the cost of the work. An important factor of the work will be the environmental impact that can occur since the lake of Nules that is located just behind the beach and declared a Municipal Natural Place, is a place of refuge for birds with importance for conservation. Another important environmental factor to take into account will be the *"caulerpa" and the "posidonia" existing in the area, for which barriers will be used in the construction., [CA] Este trabajo consiste en, primero un breve estudio de la problemática actual que sufre el frente litoral de la playa de Nules, como la erosión progresiva que sufre la playa por la dinámica litoral, donde justo el emplazamiento de la playa se ve perjudicado por barreras del transporte sólido litoral como el puerto de Burriana, otra problemática es la fuerte presión en el escarpe de la playa ejercida por las casas que se encuentran, y seguidamente una propuesta para su solución. Esta propuesta es estudiada y analizada con un estudio de soluciones que pretenderá escoger la mejor opción de actuación para resolver el problema anteriormente planteado. Se estudian 4 alternativas para escoger la mejor según una puntuación multicriterio basada en los criterios: funcional, económico, ambiental y paisajístico. En definitiva, se escoge actuar según la alternativa 1, que propone una construcción de 4 diques exentos para crear 4 hemitómbolos en la parte sur de la desembocadura del estanque de Nules, junto a una retirada de espigones transversales, y una alimentación artificial; y en la parte norte solo se procederá a la alimentación artificial. Una vez escogida la mejor opción se calcula detalladamente lo que lleva a calcular la altura de ola para calcular el peso de la escollera que formará los diques exentos. Con esto y una caracterización de los espigones existentes en la playa que se desmantelarán, se llega a que es posible una reutilización de escollera de estos espigones a retirar y se utilizará en los nuevos diques exentos. El procedimiento que se seguirá para construir estos diques es por vía terrestre sin necesidad de protonas ni maquinaria especial. Una vez calculados los diques y sus hemitómbolos, se procede a la realización de unos perfiles en la playa que caracterizarán la nueva forma de playa y serán utilizados para la cubicación del volumen a aportar de arenas en la playa de Nules. El material para esta alimentación artificial se pedirá en cantera, y tendrá un Dn50 muy similar al existente. Esta parte será la más costosa, referido a la cantidad importante de metros cúbicos que serán alrededor de 700.000, y también referido al coste de la obra. Un factor importante de la obra será el impacto ambiental que puede producir ya que el estanque de Nules que se encuentra justo detrás de la playa y declarado Paraje Natural Municipal, constituye un lugar de refugio para aves con importancia de conservación. Otro factor ambiental importante a tener en cuenta será la caulerpa y la posidonia existente en la zona, para lo que se utilizarán barreras antiturbidez en la construcción., [ES] Este trabajo consiste en, primero un breve estudio de la problemática actual que sufre el frente litoral de la playa de Nules, como la erosión progresiva que sufre la playa por la dinámica litoral, donde justo el emplazamiento de la playa se ve perjudicado por barreras del transporte sólido litoral como el puerto de Burriana, otra problemática es la fuerte presión en el escarpe de la playa ejercida por las casas que se encuentran, y seguidamente una propuesta para su solución. Esta propuesta es estudiada y analizada con un estudio de soluciones que pretenderá escoger la mejor opción de actuación para resolver el problema anteriormente planteado. Se estudian 4 alternativas para escoger la mejor según una puntuación multicriterio basada en los criterios: funcional, económico, ambiental y paisajístico. En definitiva, se escoge actuar según la alternativa 1, que propone una construcción de 4 diques exentos para crear 4 hemitómbolos en la parte sur de la desembocadura del estanque de Nules, junto a una retirada de espigones transversales, y una alimentación artificial; y en la parte norte solo se procederá a la alimentación artificial. Una vez escogida la mejor opción se calcula detalladamente lo que lleva a calcular la altura de ola para calcular el peso de la escollera que formará los diques exentos. Con esto y una caracterización de los espigones existentes en la playa que se desmantelarán, se llega a que es posible una reutilización de escollera de estos espigones a retirar y se utilizará en los nuevos diques exentos. El procedimiento que se seguirá para construir estos diques es por vía terrestre sin necesidad de protonas ni maquinaria especial. Una vez calculados los diques y sus hemitómbolos, se procede a la realización de unos perfiles en la playa que caracterizarán la nueva forma de playa y serán utilizados para la cubicación del volumen a aportar de arenas en la playa de Nules. El material para esta alimentación artificial se pedirá en cantera, y tendrá un Dn50 muy similar al existente. Esta parte será la más costosa, referido a la cantidad importante de metros cúbicos que serán alrededor de 700.000, y también referido al coste de la obra. Un factor importante de la obra será el impacto ambiental que puede producir ya que el estanque de Nules que se encuentra justo detrás de la playa y declarado Paraje Natural Municipal, constituye un lugar de refugio para aves con importancia de conservación. Otro factor ambiental importante a tener en cuenta será la caulerpa y la posidonia existente en la zona, para lo que se utilizarán barreras antiturbidez en la construcción.
- Published
- 2019
23. Analysis of functional connectivity and oscillatory power using DICS
- Author
-
van Vliet, Marijn, Liljeström, Mia, Aro, Susanna, Salmelin, Riitta, Kujala, Jan, Department of Neuroscience and Biomedical Engineering, Aalto-yliopisto, and Aalto University
- Subjects
tutorial ,MEG ,workflow ,DICS ,brain rhythms ,coherence - Abstract
Communication between brain regions is thought to be facilitated by the synchronization of oscillatory activity. Hence, large-scale functional networks within the brain may be estimated by measuring synchronicity between regions. Neurophysiological recordings, such as magnetoencephalography (MEG) and electroencephalography (EEG), provide a direct measure of oscillatory neural activity with millisecond temporal resolution. In this paper, we describe a full data analysis pipeline for functional connectivity analysis based on dynamic imaging of coherent sources (DICS) of MEG data. DICS is a beamforming technique in the frequency-domain that allows the study of the cortical sources of oscillatory activity and synchronization between brain regions. All the analysis steps, starting from the raw MEG data up to publication-ready group-level statistics and visualization, are discussed in depth, including methodological considerations, rules of thumb and tradeoffs. We start by computing cross-spectral density (CSD) matrices using a wavelet approach in several frequency bands (alpha, theta, beta, gamma). We then provide a way to create comparable source spaces across subjects and discuss the cortical mapping of spectral power. For connectivity analysis, we present a canonical computation of coherence that facilitates a stable estimation of all-to-all connectivity. Finally, we use group-level statistics to limit the network to cortical regions for which significant differences between experimental conditions are detected and produce vertex- and parcel-level visualizations of the different brain networks. Code examples using the MNE-Python package are provided at each step, guiding the reader through a complete analysis of the freely available openfMRI ds000117 "familiar vs. unfamiliar vs. scrambled faces" dataset. The goal is to educate both novice and experienced data analysts with the "tricks of the trade" necessary to successfully perform this type of analysis on their own data.
- Published
- 2018
24. Evolució d'ultrapassament en un dic en talús al llarg d'un temporal amb eines experimentals
- Author
-
Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Gironella Cobos, Xavier, Marzeddu, Andrea, Toha Vilanova, Damia, Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Gironella Cobos, Xavier, Marzeddu, Andrea, and Toha Vilanova, Damia
- Published
- 2018
25. Projecte d'ampliació i adaptació a grans eslores del dic de llevant del port d'Arenys
- Author
-
Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Fillola Caraballo, Elena, Mas Sancho, Marta, Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Fillola Caraballo, Elena, and Mas Sancho, Marta
- Published
- 2018
26. Auditoria del projecte executiu de millora de la resposta de la infraestructura a temporals al Port Fòrum : informe sobre la resposta donada pel projectista
- Author
-
Gerència d'Ecologia Urbana and Marciglob Consultancy Solutions, S.L.
- Subjects
Urbanisme i infraestructures ,Auditoria ,Enginyeria de costes ,informes altres ,Auditing ,Ocean waves ,Obras públicas ,Obres públiques ,Dics ,Public works ,Coastal engineering ,Olas ,Onades ,Auditoría ,Dikes (Engineering) ,Diques ,Ingeniería de costas - Abstract
Sol·licitant de l’informe: Gerència d'Ecologia Urbana
- Published
- 2018
27. BrainmappingNeuronal Networks in Children with Continuous Spikes and Waves during Slow Sleep as revealed by DICS and RPDC
- Author
-
Dierck, Carina, Stephani, Ulrich, and Siniatchkin, Michael
- Subjects
doctoral thesis ,epileptic encephalopathy ,Abschlussarbeit ,CSWS ,Neuroimaging ,ddc:610 ,neuronal networks ,DICS ,ddc:6XX ,RPDC - Abstract
CSWS is an age-related epileptic encephalopathy consisting of the triad of seizures, neuropsychological impairment and a specific EEG-pattern. This EEG-pattern is characterized by spike-and-wave-discharges emphasized during non-REM sleep. Until now, little has been known about the pathophysiologic processes. So far research approaches on the underlying neuronal network have been based on techniques with a good spatial but poor temporal resolution like fMRI and FDG-PET. In this study the search for sources participating in the neuronal network of CSWS is done by processing EEG-data with high temporal resolution. This allows not only interferences on the location of the individual sources but also on the direction of information flow between them. DICS is applied to the data to solve the inverse problem in the frequency domain. Afterwards RPDC, based on Granger causality, is implemented to reveal effective connectivity between the sources. 12 patients suffering from CSWS without any proof for macroscopic cerebral pathologies in a T1-MRI were investigated at two points of time, before and after treatment. All results are compared to other studies on the neuronal network of CSWS, to knowledge about genesis of epileptic activity in general and to knowledge about the pathogenesis of related psychiatric syndromes. During the active phase of CSWS the thalamus represents the central hub of the neuronal network, and also the cerebellum and key nodes of the DMN contribute to it. Therefore the results are concordant to the ones of former studies and to assumptions on the genesis of epileptic activity. In addition, pathogenetic parallels are found to autism, ADHD and memory-impairment. After cessation of CSWS, the network consists of exclusively cortical sources. In addition to the SWI the mean absolute source power, the mean coherence strength and the mean RPDC strength could be revealed as reliable indicators for the severity of the encephalopathy.
- Published
- 2018
28. Estudi ambiental Port Olímpic
- Author
-
Gerència d'Ecologia Urbana and Dac Enviro S. L.
- Subjects
Ports ,Urbanisme i infraestructures ,Evaluación de impacto ambiental ,Enginyeria de costes ,informes altres ,Ocean waves ,Dics ,Coastal engineering ,Puertos ,Port Olímpic de Barcelona ,Avaluació de l'impacte ambiental ,Olas ,Retaining walls ,Muros de contención ,Murs de contenció ,Environmental impact analysis ,Harbors ,Onades ,Dikes (Engineering) ,Diques ,Ingeniería de costas - Abstract
Sol·licitant de l'informe: Gerència d'Ecologia Urbana
- Published
- 2018
29. Evolució d'ultrapassament en un dic en talús al llarg d'un temporal amb eines experimentals
- Author
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Toha Vilanova, Damia, Gironella Cobos, Xavier, Marzeddu, Andrea, and Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental
- Subjects
Talussos (Mecànica dels sòls) ,Enginyeria civil [Àrees temàtiques de la UPC] ,Slopes (Soil mechanics) ,Ultrapassament ,Dikes (Engineering) ,Dics ,Cabal ,Overtopping - Published
- 2018
30. Metodología para la obtención y análisis de las condiciones de oleaje en zonas sin datos instrumentales. Aplicación a la evaluación de los efectos del cambio climático en el diseño del dique de la ampliación de la zona norte del puerto de Veracruz (México)
- Author
-
Martínez Cantero, Javier
- Subjects
Wave height ,Infradimensionament ,Climate Change ,INGENIERIA E INFRAESTRUCTURA DE LOS TRANSPORTES ,Estabilitat del manto ,Canvi Climàtic ,Ultrapassament ,Nivel del mar ,Oleaje ,Altura de ola ,Diques ,Altura d'onada ,Armour stability ,Dics ,Rebase ,Overtopping ,Estabilidad del manto ,Máster Universitario en Ingeniería de Caminos, Canales y Puertos-Màster Universitari en Enginyeria de Camins, Canals i Ports ,Underdesigned ,Infradimensionamiento ,Nivell del mar ,Cambio Climático ,Waves ,Breakwaters ,Sea Level ,Onatge - Abstract
[EN] Coastal defense structures play a major role in the development of ports. As ports are central elements to the local economy, the operability, functionality and safety of their infrastructures must be ensured. Hence, a reliable design of their defense structures, like breakwaters, is needed. Determining the characteristics of the marine climate is fundamental to a breakwater design. By using the script provided in this Master Thesis, it is possible to obtain, with a certain reliability, data on wave conditions in geographic areas without measuring instruments or local data. The American database created by the National Oceanic and Atmospheric Administration lies at the basis of the script developed. Climate Change affects marine weather conditions, making coastal structures predictably more vulnerable to future marine conditions. This fact could endanger the structural integrity of the designed breakwaters. Due to the ability to obtain wave data in any part of the world, this Master Thesis is able to analyze the wave conditions of the surroundings of the project of Veracruz North Port extension. A temporal analysis of waves along with the predictions of sea level rise provided by the International Panel on Climate Change, allowed for future predictions of the marine climate at the end of the XXI century to be made. These conditions show that the breakwater cross section studied is under-designed against future conditions. Discharges due to overtopping will increase in a range from 13% to 27 %, while the armour stability will need an increase between 3% and 10% of its elements weight to meet present design requirements. These results highlight the need to consider a design factor which will take into account Climate Change and its threat against existing and future port structures., [CA] Les obres d'abric juguen un paper essencial en l'esdevindre dels Ports. Estos són el motor de l'economia i han d'assegurar l'operativitat, funcionalitat i seguretat de les seues infraestructures. Per això és necessari un correcte disseny de les obres d'abric, com en el cas dels dics. La determinació del clima marítim és una fase fonamental en el disseny i per mitjà del codi exposat en este Treball Final de Màster, es podrà obtindre amb una certa fiabilitat dades relatives a l'onatge en zones geogràfiques que no tinguen instruments de mesura o dades d'onatge. La base de dades americanes de la National Oceanic and Atmospheric Administration és la base de l'algoritme desenvolupat. El Canvi Climàtic té efectes sobre el clima marítim, fent les estructures costaneres previsiblement més vulnerables a les condicions climàtiques futures. Este fet pot fer perillar els requisits de les obres d'abric dissenyades. Podent obtindre dades d'onatge en qualsevol part del món, este Treball Final de Màster analitza l'onatge característic de l'entorn del projecte d'Ampliació de la zona nord del Port de Veracruz. L'anàlisi temporal de l'onatge junt a les prediccions d'increment del nivell mitjà del mar proposades per el International Panel on Climate Change, permeten fer una predicció de les condicions d'onatge a finals de segle XXI. Estes mostren l'infradimensionament de la secció del dic d'estudi enfront de condicions venidores. L'ultrapassament previst augmentarà les seues descàrregues entre un 13% i 7% , mentres que l'estabilitat del manto no podrà complir els requeriments de disseny actuals, requerint un increment entre el 3% i 10% del pes dels elements que ho conformen. Estos resultats posen de manifest la necessitat d'incorporar en els dissenys un factor que considere el Canvi Climàtic i l'amenaça que este genera sobre les obres portuàries existents i futures., [ES] Las obras de abrigo juegan un papel esencial en el devenir de los Puertos. Éstos son el motor de la economía y han de asegurar la operatividad, funcionalidad y seguridad de sus infraestructuras. Por ello es necesario un correcto diseño de las obras de abrigo, como los diques. La determinación del clima marítimo es una fase fundamental en el diseño y mediante el código expuesto en este Trabajo Final de Máster, se podrá obtener con cierta fiabilidad datos relativos al oleaje en zonas geográficas que carezcan de instrumentos de medición o datos al respecto. La base de datos americana de la National Oceanic and Atmospheric Administration es la base del algoritmo desarrollado. El Cambio Climático tiene efectos sobre el clima marítimo, haciendo las estructuras costeras previsiblemente más vulnerables a las condiciones climáticas futuras. Este hecho puede hacer peligrar los requisitos de las obras de abrigo diseñadas. Pudiendo obtener datos de oleaje en cualquier parte del mundo, este Trabajo Final de Máster analiza el oleaje característico del entorno del proyecto de Ampliación de la zona norte del Puerto de Veracruz. El análisis temporal del oleaje junto con las predicciones de incremento del nivel medio del mar propuestas por el International Panel on Climate Change, permiten hacer una predicción de las condiciones de oleaje a finales de siglo XXI. Éstas muestran el infradimensionamiento de la sección del dique de estudio frente a condiciones venideras. El rebase previsto aumentará sus descargas entre un 13% y 27% , mientras que la estabilidad del manto no podrá cumplir los requerimientos de diseño actuales, necesitando un incremento entre el 3% y 10% del peso de los elementos que lo conforman. Estos resultados ponen de manifiesto la necesidad de incorporar en los diseños un factor que considere el Cambio Climático y la amenaza que este genera sobre las obras portuarias existentes y futuras.
- Published
- 2017
31. Estudio en modelo físico del Port Fòrum de Barcelona : informe final
- Author
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Enginyeria Reventós, S.L., Gerència Adjunta de Mobilitat i Infraestructures, Grupo de Ingeniería del Agua y del Medio Ambiente (GEAMA), and Universidade da Coruña
- Subjects
Climatology ,Urbanisme i infraestructures ,Enginyeria de costes ,informes altres ,Dics ,Coastal engineering ,Retaining walls ,Muros de contención ,Climatología ,Murs de contenció ,Climatologia ,Dikes (Engineering) ,Diques ,Ingeniería de costas - Abstract
Sol·licitant de l’informe: Gerència Adjunta de Mobilitat i Infraestructures El camp autors també inclou als autors de l'annex
- Published
- 2017
32. Quantitative Evaluation in Estimating Sources Underlying Brain Oscillations Using Current Source Density Methods and Beamformer Approaches
- Author
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Siddharth Talwar, Tamesh Halder, Arpan Banerjee, and Amit Kumar Jaiswal
- Subjects
Steady state (electronics) ,Brain activity and meditation ,Computer science ,Dynamic imaging ,eLORETA ,Signal-To-Noise Ratio ,Electroencephalography ,Novel Tools and Methods ,DICS ,Minimum-variance unbiased estimator ,medicine ,Humans ,EEG ,Sensitivity (control systems) ,LCMV ,Ground truth ,Confirmation ,MEG ,medicine.diagnostic_test ,business.industry ,General Neuroscience ,Brain ,Magnetoencephalography ,Reproducibility of Results ,Signal Processing, Computer-Assisted ,Pattern recognition ,General Medicine ,Current source ,Brain Waves ,Electrophysiological Phenomena ,7.6 ,Artificial intelligence ,business ,Algorithms ,MNE - Abstract
Brain oscillations from EEG and MEG shed light on neurophysiological mechanisms of human behavior. However, to extract information on cortical processing, researchers have to rely on source localization methods that can be very broadly classified into current density estimates such as exact low-resolution brain electromagnetic tomography (eLORETA), minimum norm estimates (MNE), and beamformers such as dynamic imaging of coherent sources (DICS) and linearly constrained minimum variance (LCMV). These algorithms produce a distributed map of brain activity underlying sustained and transient responses during neuroimaging studies of behavior. On the other hand, there are very few comparative analyses that evaluates the “ground truth detection” capabilities of these methods. The current article evaluates the reliability in estimation of sources of spectral event generators in the cortex using a two-pronged approach. First, simulated EEG data with point dipoles and distributed dipoles are used to validate the accuracy and sensitivity of each one of these methods of source localization. The abilities of the techniques were tested by comparing the localization error, focal width, false positive (FP) ratios while detecting already known location of neural activity generators under varying signal-to-noise ratios (SNRs). Second, empirical EEG data during auditory steady state responses (ASSRs) in human participants were used to compare the distributed nature of source localization. All methods were successful in recovery of point sources in favorable signal to noise scenarios and could achieve high hit rates if FPs are ignored. Interestingly, focal activation map is generated by LCMV and DICS when compared to eLORETA while control of FPs is much superior in eLORETA. Subsequently drawbacks and strengths of each method are highlighted with a detailed discussion on how to choose a technique based on empirical requirements.
- Published
- 2019
- Full Text
- View/download PDF
33. Estudio de viabilidad de cajones marítimos con hormigón con fibras
- Author
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Ramos Marquès, Òscar Gonçal, Aguado de Cea, Antonio, Ainchil Lavín, Javier Pablo, and Universitat Politècnica de Catalunya. Departament d'Enginyeria de la Construcció
- Subjects
Construcció en formigó armat amb fibres ,Cajón marítimo ,Reinforced concrete construction ,Enginyeria civil::Materials i estructures [Àrees temàtiques de la UPC] ,Dikes (Engineering) ,Dics ,Fibras ,Hormigón con fibras - Abstract
En este TFM se estudia la viabilidad de sustituir la armadura pasiva por fibras metálicas o plásticas en cajones para obras portuarias. Para ello, en primer lugar, se estudia el procedimiento constructivo de un cajón y las propiedades de los hormigones con fibras. Una vez analizado el estado del conocimiento se procede a escoger un cajón representativo, ya construido con armadura pasiva. El cajón escogido es el cajón tipo 3 del dique este del puerto de Castellón. Este cajón tiene una longitud de 41.27 m, un ancho de 23.85m y su altura total es de 17.50 m. El cajón se analiza mediante un modelo de cálculo 3D con elementos finitos, desarrollado con SAP2000, que permite obtener los esfuerzos. A partir de estos esfuerzos se comprueba si es viable la sustitución de la armadura pasiva en los tabiques, tanto interiores como exteriores, evaluando los flectores y cortantes últimos (ELU) del hormigón con fibras, obteniéndose el valor necesario de fR3k . Se determina también la fisuración en Estado Límite de Servicio para, a partir de una abertura de fisura de 0,2 mm, obtener el valor necesario de fR1k. Este proceso se realiza primero para un cajón con celdas cuadradas, después para un cajón de mismas dimensiones interiores y exteriores pero con celdas circulares y por último para un cajón con celdas circulares con las mismas dimensiones exteriores pero con el interior optimizado para disminuir el volumen de hormigón necesario. En el caso en que los esfuerzos exijan resistencias a la flexotracción y, en consecuencia, cuantías por encima de las razonables, como sucede en cajones con celdas rectangulares, se procede al incremento de los espesores y a la evaluación de dimensiones de cartelas. También se ha diferenciado entre cajones destinados a diques y cajones destinados a muelles al estar solicitados por acciones distintas. Igualmente se ha estudiado la posibilidad de utilizar hormigón con fibras plásticas, las cuales desarrollan valores de fR1k y fR3k máximos cercanos a los que desarrollan las cuantías mínimas de fibras de acero. Finalmente se realiza una comparación de mediciones y de presupuesto de las diferentes soluciones planteadas, a partir de precios reales de mano de obra y materiales. De todo el estudio se extraen conclusiones que permiten afrontar el diseño de estos elementos sin armadura convencional. This Master Thesis studies the feasibility of replacing the conventional reinforcement by steel or plastic fibers in maritime caissons. Firstly, a literature review on the constructive procedure of a caisson and the properties of fiber reinforced concrete is developed. Then, a representative caisson, already constructed with conventional reinforcement, is chosen. The caisson breakwater chosen is the type 3 of project for the east breakwater of the port of Castellón. This caisson has a length of 41.27 m, a width of 23.85 m and a total height of 17.50 m. The caisson has been analyzed by a 3D finite element model developed with SAP2000, to obtain the internal forces. From this internal forces, it is possible to verify if the substitution of the conventional reinforcement is feasible, evaluating both the ultimate limit strength (ULS) of the fiber concrete in bending and shear, where the necessary value of fR3k is obtained. Cracking is also determined in Service Limit State (SLS) to obtain the required value of fR1k from a crack width of 0.2 mm. This process is done first for the caisson with square cells, then for the caisson of the same internal and external dimensions but with circular cells and finally for a caisson with circular cells with the same exterior but with the interior optimized to decrease the volume of concrete required. If the required ultimate tensile strength of the concrete, and hence, the amount of fibers, are larger than the usual ones, as for instance for caissons with rectangular cells, an increase of the depths of the walls or the use of gussets are studied. In addition, as the loads for caissons for breakwaters and the ones used for docks are different, both have been studied. Moreover, the study includes the possibility of using plastic fiber reinforced concrete, which develops maximum values of fR1k y fR3k close to those developed with the minimum amount of steel fibers. Finally, the amount of materials and the cost are compared for the different solutions, based on real prices of labor and materials. Conclusions on the feasibility of designing maritime caissons with plastic and steel fiber reinforced concrete are included.
- Published
- 2017
34. Estudi ambiental projecte millora infraestructura del Port Fòrum
- Author
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Gerència d'Ecologia Urbana and Dac Enviro S. L.
- Subjects
Climatology ,Urbanisme i infraestructures ,Enginyeria de costes ,informes altres ,Medi ambient ,Ocean waves ,Dics ,Coastal engineering ,Olas ,Retaining walls ,Muros de contención ,Climatología ,Murs de contenció ,Climatologia ,Onades ,Dikes (Engineering) ,Diques ,Ingeniería de costas - Abstract
Sol·licitant de l’informe: Gerència d'Ecologia Urbana
- Published
- 2017
35. Estudi impacte sobre dinàmica litoral al Port Fòrum
- Author
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Gerència d'Ecologia Urbana and Enginyeria Reventós, S.L.
- Subjects
Urbanisme i infraestructures ,Enginyeria de costes ,informes altres ,Ocean waves ,Obras públicas ,Obres públiques ,Dics ,Public works ,Coastal engineering ,Olas ,Onades ,Dikes (Engineering) ,Diques ,Ingeniería de costas - Abstract
Sol·licitant de l’informe: Gerència d'Ecologia Urbana
- Published
- 2017
36. Neuronal networks of burst suppression EEG as revealed by source analysis and renormalized partial directed coherence
- Author
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Reinicke, Christine, Stephani, Ulrich, and Laufs, Helmut
- Subjects
doctoral thesis ,Abschlussarbeit ,Medizinische Fakultät ,source analysis, DICS, epileptc encephalopathy, burst suppression ,epileptc encephalopathy ,source analysis ,ddc:610 ,DICS ,burst suppression ,ddc:6XX ,Faculty of Medicine - Abstract
Burst-suppression (BS) is an electroencephalography (EEG) pattern consist-ing of alternative periods of slow waves of high amplitude (the burst) and periods of so called flat EEG (the suppression). It is generally associated with the reduced level of consciousness. The aim of this study was to reveal the neuronal network underlying both burst and suppression phases using a source analysis method: dynamic imaging of coherent sources (DICS) and to describe the effective connectivity between the identified sources using renormalized partial directed coherence (RPDC). DICS was applied separately to the EEG segments of 13 neonates with burst and suppression EEG pattern. Power spectrum analyses were performed to identify the predominant frequencies. The brain area with the strongest power in the analyzed frequency (1-4 Hz) range was defined as the reference region. DICS was used to compute the coher-ence between this reference region and the entire brain. RPDC was used to describe the in-formational flow between the described sources. Delta activity during burst phases was associated with sources in the thalamus and brainstem as well as bilateral sources in the cortical regions mainly frontal and parietal, whereas suppression phases were associated with coherent sources only in the cor-tical regions. Results of the RPDC analyses showed an ascending informational flow from the brainstem towards the thalamus and from the thalamus to cortical regions, which was absent during suppression phases. Especially those brain regions were affected, that are im-portant for cognitive processing. The results of this study strengthen the assumption that there is a specific periodicity of neural activity and that thalamocortical deafferentiation is an essential feature of BS. Thus a burst can be understood as short, repetitive recovery of cortical neural dynamics. The described deafferentation may play a role in the poor neuro-logical outcome in these encephalopathies.
- Published
- 2017
37. Metodología para la obtención y análisis de las condiciones de oleaje en zonas sin datos instrumentales. Aplicación a la evaluación de los efectos del cambio climático en el diseño del dique de la ampliación de la zona norte del puerto de Veracruz (México)
- Author
-
González Escrivá, José Alberto, Molines Llodra, Jorge, Universitat Politècnica de València. Departamento de Ingeniería e Infraestructura de los Transportes - Departament d'Enginyeria i Infraestructura dels Transports, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos - Escola Tècnica Superior d'Enginyers de Camins, Canals i Ports, Universitat Politècnica de València. Instituto del Transporte y Territorio - Institut del Transport i Territori, Martínez Cantero, Javier, González Escrivá, José Alberto, Molines Llodra, Jorge, Universitat Politècnica de València. Departamento de Ingeniería e Infraestructura de los Transportes - Departament d'Enginyeria i Infraestructura dels Transports, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros de Caminos, Canales y Puertos - Escola Tècnica Superior d'Enginyers de Camins, Canals i Ports, Universitat Politècnica de València. Instituto del Transporte y Territorio - Institut del Transport i Territori, and Martínez Cantero, Javier
- Abstract
[EN] Coastal defense structures play a major role in the development of ports. As ports are central elements to the local economy, the operability, functionality and safety of their infrastructures must be ensured. Hence, a reliable design of their defense structures, like breakwaters, is needed. Determining the characteristics of the marine climate is fundamental to a breakwater design. By using the script provided in this Master Thesis, it is possible to obtain, with a certain reliability, data on wave conditions in geographic areas without measuring instruments or local data. The American database created by the National Oceanic and Atmospheric Administration lies at the basis of the script developed. Climate Change affects marine weather conditions, making coastal structures predictably more vulnerable to future marine conditions. This fact could endanger the structural integrity of the designed breakwaters. Due to the ability to obtain wave data in any part of the world, this Master Thesis is able to analyze the wave conditions of the surroundings of the project of Veracruz North Port extension. A temporal analysis of waves along with the predictions of sea level rise provided by the International Panel on Climate Change, allowed for future predictions of the marine climate at the end of the XXI century to be made. These conditions show that the breakwater cross section studied is under-designed against future conditions. Discharges due to overtopping will increase in a range from 13% to 27 %, while the armour stability will need an increase between 3% and 10% of its elements weight to meet present design requirements. These results highlight the need to consider a design factor which will take into account Climate Change and its threat against existing and future port structures., [CA] Les obres d'abric juguen un paper essencial en l'esdevindre dels Ports. Estos són el motor de l'economia i han d'assegurar l'operativitat, funcionalitat i seguretat de les seues infraestructures. Per això és necessari un correcte disseny de les obres d'abric, com en el cas dels dics. La determinació del clima marítim és una fase fonamental en el disseny i per mitjà del codi exposat en este Treball Final de Màster, es podrà obtindre amb una certa fiabilitat dades relatives a l'onatge en zones geogràfiques que no tinguen instruments de mesura o dades d'onatge. La base de dades americanes de la National Oceanic and Atmospheric Administration és la base de l'algoritme desenvolupat. El Canvi Climàtic té efectes sobre el clima marítim, fent les estructures costaneres previsiblement més vulnerables a les condicions climàtiques futures. Este fet pot fer perillar els requisits de les obres d'abric dissenyades. Podent obtindre dades d'onatge en qualsevol part del món, este Treball Final de Màster analitza l'onatge característic de l'entorn del projecte d'Ampliació de la zona nord del Port de Veracruz. L'anàlisi temporal de l'onatge junt a les prediccions d'increment del nivell mitjà del mar proposades per el International Panel on Climate Change, permeten fer una predicció de les condicions d'onatge a finals de segle XXI. Estes mostren l'infradimensionament de la secció del dic d'estudi enfront de condicions venidores. L'ultrapassament previst augmentarà les seues descàrregues entre un 13% i 7% , mentres que l'estabilitat del manto no podrà complir els requeriments de disseny actuals, requerint un increment entre el 3% i 10% del pes dels elements que ho conformen. Estos resultats posen de manifest la necessitat d'incorporar en els dissenys un factor que considere el Canvi Climàtic i l'amenaça que este genera sobre les obres portuàries existents i futures., [ES] Las obras de abrigo juegan un papel esencial en el devenir de los Puertos. Éstos son el motor de la economía y han de asegurar la operatividad, funcionalidad y seguridad de sus infraestructuras. Por ello es necesario un correcto diseño de las obras de abrigo, como los diques. La determinación del clima marítimo es una fase fundamental en el diseño y mediante el código expuesto en este Trabajo Final de Máster, se podrá obtener con cierta fiabilidad datos relativos al oleaje en zonas geográficas que carezcan de instrumentos de medición o datos al respecto. La base de datos americana de la National Oceanic and Atmospheric Administration es la base del algoritmo desarrollado. El Cambio Climático tiene efectos sobre el clima marítimo, haciendo las estructuras costeras previsiblemente más vulnerables a las condiciones climáticas futuras. Este hecho puede hacer peligrar los requisitos de las obras de abrigo diseñadas. Pudiendo obtener datos de oleaje en cualquier parte del mundo, este Trabajo Final de Máster analiza el oleaje característico del entorno del proyecto de Ampliación de la zona norte del Puerto de Veracruz. El análisis temporal del oleaje junto con las predicciones de incremento del nivel medio del mar propuestas por el International Panel on Climate Change, permiten hacer una predicción de las condiciones de oleaje a finales de siglo XXI. Éstas muestran el infradimensionamiento de la sección del dique de estudio frente a condiciones venideras. El rebase previsto aumentará sus descargas entre un 13% y 27% , mientras que la estabilidad del manto no podrá cumplir los requerimientos de diseño actuales, necesitando un incremento entre el 3% y 10% del peso de los elementos que lo conforman. Estos resultados ponen de manifiesto la necesidad de incorporar en los diseños un factor que considere el Cambio Climático y la amenaza que este genera sobre las obras portuarias existentes y futuras.
- Published
- 2017
38. Estudio de viabilidad de cajones marítimos con hormigón con fibras
- Author
-
Universitat Politècnica de Catalunya. Departament d'Enginyeria de la Construcció, Aguado de Cea, Antonio, Ainchil Lavín, Javier Pablo, Ramos Marquès, Òscar Gonçal, Universitat Politècnica de Catalunya. Departament d'Enginyeria de la Construcció, Aguado de Cea, Antonio, Ainchil Lavín, Javier Pablo, and Ramos Marquès, Òscar Gonçal
- Abstract
En este TFM se estudia la viabilidad de sustituir la armadura pasiva por fibras metálicas o plásticas en cajones para obras portuarias. Para ello, en primer lugar, se estudia el procedimiento constructivo de un cajón y las propiedades de los hormigones con fibras. Una vez analizado el estado del conocimiento se procede a escoger un cajón representativo, ya construido con armadura pasiva. El cajón escogido es el cajón tipo 3 del dique este del puerto de Castellón. Este cajón tiene una longitud de 41.27 m, un ancho de 23.85m y su altura total es de 17.50 m. El cajón se analiza mediante un modelo de cálculo 3D con elementos finitos, desarrollado con SAP2000, que permite obtener los esfuerzos. A partir de estos esfuerzos se comprueba si es viable la sustitución de la armadura pasiva en los tabiques, tanto interiores como exteriores, evaluando los flectores y cortantes últimos (ELU) del hormigón con fibras, obteniéndose el valor necesario de fR3k . Se determina también la fisuración en Estado Límite de Servicio para, a partir de una abertura de fisura de 0,2 mm, obtener el valor necesario de fR1k. Este proceso se realiza primero para un cajón con celdas cuadradas, después para un cajón de mismas dimensiones interiores y exteriores pero con celdas circulares y por último para un cajón con celdas circulares con las mismas dimensiones exteriores pero con el interior optimizado para disminuir el volumen de hormigón necesario. En el caso en que los esfuerzos exijan resistencias a la flexotracción y, en consecuencia, cuantías por encima de las razonables, como sucede en cajones con celdas rectangulares, se procede al incremento de los espesores y a la evaluación de dimensiones de cartelas. También se ha diferenciado entre cajones destinados a diques y cajones destinados a muelles al estar solicitados por acciones distintas. Igualmente se ha estudiado la posibilidad de utilizar hormigón con fibras plásticas, las cuales desarrollan valores de fR1k y fR3k máximos cercanos a los q, This Master Thesis studies the feasibility of replacing the conventional reinforcement by steel or plastic fibers in maritime caissons. Firstly, a literature review on the constructive procedure of a caisson and the properties of fiber reinforced concrete is developed. Then, a representative caisson, already constructed with conventional reinforcement, is chosen. The caisson breakwater chosen is the type 3 of project for the east breakwater of the port of Castellón. This caisson has a length of 41.27 m, a width of 23.85 m and a total height of 17.50 m. The caisson has been analyzed by a 3D finite element model developed with SAP2000, to obtain the internal forces. From this internal forces, it is possible to verify if the substitution of the conventional reinforcement is feasible, evaluating both the ultimate limit strength (ULS) of the fiber concrete in bending and shear, where the necessary value of fR3k is obtained. Cracking is also determined in Service Limit State (SLS) to obtain the required value of fR1k from a crack width of 0.2 mm. This process is done first for the caisson with square cells, then for the caisson of the same internal and external dimensions but with circular cells and finally for a caisson with circular cells with the same exterior but with the interior optimized to decrease the volume of concrete required. If the required ultimate tensile strength of the concrete, and hence, the amount of fibers, are larger than the usual ones, as for instance for caissons with rectangular cells, an increase of the depths of the walls or the use of gussets are studied. In addition, as the loads for caissons for breakwaters and the ones used for docks are different, both have been studied. Moreover, the study includes the possibility of using plastic fiber reinforced concrete, which develops maximum values of fR1k y fR3k close to those developed with the minimum amount of steel fibers. Finally, the amount of materials and the cost are compared for the diffe
- Published
- 2017
39. Task-Modulated Corticocortical Synchrony in the Cognitive-Motor Network Supporting Handwriting.
- Author
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Saarinen T, Kujala J, Laaksonen H, Jalava A, and Salmelin R
- Subjects
- Adult, Brain Mapping methods, Cognition physiology, Female, Humans, Male, Movement physiology, Nerve Net physiology, Young Adult, Brain physiology, Hand physiology, Handwriting, Motor Cortex physiology, Psychomotor Performance physiology
- Abstract
Both motor and cognitive aspects of behavior depend on dynamic, accurately timed neural processes in large-scale brain networks. Here, we studied synchronous interplay between cortical regions during production of cognitive-motor sequences in humans. Specifically, variants of handwriting that differed in motor variability, linguistic content, and memorization of movement cues were contrasted to unveil functional sensitivity of corticocortical connections. Data-driven magnetoencephalography mapping (n = 10) uncovered modulation of mostly left-hemispheric corticocortical interactions, as quantified by relative changes in phase synchronization. At low frequencies (~2-13 Hz), enhanced frontoparietal synchrony was related to regular handwriting, whereas premotor cortical regions synchronized for simple loop production and temporo-occipital areas for a writing task substituting normal script with loop patterns. At the beta-to-gamma band (~13-45 Hz), enhanced synchrony was observed for regular handwriting in the central and frontoparietal regions, including connections between the sensorimotor and supplementary motor cortices and between the parietal and dorsal premotor/precentral cortices. Interpreted within a modular framework, these modulations of synchrony mainly highlighted interactions of the putative pericentral subsystem of hand coordination and the frontoparietal subsystem mediating working memory operations. As part of cortical dynamics, interregional phase synchrony varies depending on task demands in production of cognitive-motor sequences., (© The Author(s) 2019. Published by Oxford University Press.)
- Published
- 2020
- Full Text
- View/download PDF
40. Ampliació del dic de recer del port de Tarragona
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Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental, Gironella Cobos, Xavier, Gracia Garcia, Vicente, Kröger, Arne, Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental, Gironella Cobos, Xavier, Gracia Garcia, Vicente, and Kröger, Arne
- Published
- 2016
41. Projecte d'ampliació del port de Benidorm
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Surroca Calvo, Enrique, Sierra Pedrico, Juan Pablo, Gracia Garcia, Vicente, and Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental
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Ports ,Benidorm ,Harbors ,marina ,Enginyeria civil::Enginyeria hidràulica, marítima i sanitària::Ports i costes [Àrees temàtiques de la UPC] ,instal·lacions ,ampliació ,amarradors ,port ,obres ,construcció ,dics - Published
- 2015
42. Ampliación sur del puerto de Casas de Alcanar (Tarragona): estudio de soluciones, diques, red de abastecimiento y aspectos comunes
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Hernández González, Daniel
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Expansion ,Xarxa d'abastiment ,Supply networks ,Common alities ,Ampliació ,Dics ,Puerto ,Red de abastecimiento ,Aspectos comunes ,Ampliación ,Port ,Grado en Ingeniería Civil-Grau en Enginyeria Civil ,Aspectes comuns ,PROYECTOS DE INGENIERIA ,Obras de abrigo ,Dykes - Abstract
[EN] This project seeks to study the ampliation of the recreational and fishing port of "Las casas de Alcanar", bringing together all of the basic and necessary aspects involved in the design of a port. It has been put together by four students who, by working together, have built a working team. In the project, the knowledge acquired throughout the degree's subjects have been applied, being all collected in it. The project first analyses the basic aspects of previous studies useful before starting the design, these being a study of the current state, climatology, types of boats, demand study, topography, quarry location etc. Putting together all of this, several alternatives are brought up for the ampliation of the port. What follows up once the solution that best satisfies the demands and needs is chosen, is the designing of the structures of the dams, quays and piers as well as the dimensioning of the lighting, electrical, water supply, sanitary and service networks, amongst others. At the end, a safety and health study, an environmental impact study, a work plan, a bidding/tender and, [CA] L'objectiu del projecte de l'ampliació del port esportiu-pesquer de Las Casas de Alcanar, és el de recollir tots els aspectes bàsics i necessaris per al càlcul i disseny d'un port. Està confeccionat per quatre alumnes, els quals hem treballat en equip per a conformar un grup de treball. En tal projecte s'intenten aplicar els coneixements adquirits en les assignatures de la titulació, cosa que queda recollida en el mateix. El projecte analitza, en primer lloc, els aspectes bàsics d'estudis per a poder començar el dimensionament, com poden ser: estudi de l'estat actual, climatologia, flota tipus, estudi de demanda, topografia, localització de canteres, etc. Amb tot açò es plantegen diverses tipologies d'ampliació al port actual. Una vegada seleccionada la solució més adient, es procedeix al disseny i càlcul de les estructures de: dics, molls i pantanals; així com el dimensionament de les xarxes d'enllumenat i elèctriques, abastiment, sanejament, bocana, serveis, etc. Per a finalitzar, s'elaboren els documents del projecte com són: estudi de seguretat i salut, estudi d'impacte ambiental, pla d'obra, plecs i memòria., [ES] El objetivo del proyecto de la Ampliación del puerto deportivo y pesquero de Las Casas de Alcanar, es el de recoger todos los aspectos básicos y necesarios para el cálculo y diseño de un puerto. Está confeccionado por 4 alumnos, los cuales han trabajado en equipo para crear un grupo de trabajo.
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- 2014
43. Anàlisi del potencial impacte del canvi climàtic en l'estabilitat dels dics portuaris. Aplicació a la costa catalana
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Lebbar Palomar, Yasmine, Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental, and Sierra Pedrico, Juan Pablo
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Enginyeria civil::Enginyeria hidràulica, marítima i sanitària::Ports i costes [Àrees temàtiques de la UPC] ,Dikes (Engineering) ,Climatic changes ,Dics ,Canvis climàtics - Published
- 2014
44. Determinación de presiones y esfuerzos en diques verticales y comparativa con los resultados obtenidos medinate instrumentación propia
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Pavia Balius, Alejandra, Universitat Politècnica de Catalunya. Departament d'Infraestructura del Transport i del Territori, and Monso de Prat, José Luis
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pulsatil ,vertical ,dique ,Enginyeria civil::Enginyeria hidràulica, marítima i sanitària::Ports i costes [Àrees temàtiques de la UPC] ,subpresiones ,impacto ,Onades ,Dikes (Engineering) ,Ocean waves ,goda ,Dics ,instrumentación - Published
- 2014
45. Projecte de reforç del dic de recer de Port de la Selva (Girona)
- Author
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Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental, Gironella Cobos, Xavier, Ocete Manero, Sergio, Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental, Gironella Cobos, Xavier, and Ocete Manero, Sergio
- Published
- 2015
46. Projecte d'ampliació del port de Benidorm
- Author
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Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental, Sierra Pedrico, Juan Pablo, Gracia Garcia, Vicente, Surroca Calvo, Enrique, Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental, Sierra Pedrico, Juan Pablo, Gracia Garcia, Vicente, and Surroca Calvo, Enrique
- Published
- 2015
47. Quantitative Evaluation in Estimating Sources Underlying Brain Oscillations Using Current Source Density Methods and Beamformer Approaches.
- Author
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Halder T, Talwar S, Jaiswal AK, and Banerjee A
- Subjects
- Algorithms, Electrophysiological Phenomena, Humans, Reproducibility of Results, Signal-To-Noise Ratio, Brain physiology, Brain Waves, Electroencephalography, Magnetoencephalography, Signal Processing, Computer-Assisted
- Abstract
Brain oscillations from EEG and MEG shed light on neurophysiological mechanisms of human behavior. However, to extract information on cortical processing, researchers have to rely on source localization methods that can be very broadly classified into current density estimates such as exact low-resolution brain electromagnetic tomography (eLORETA), minimum norm estimates (MNE), and beamformers such as dynamic imaging of coherent sources (DICS) and linearly constrained minimum variance (LCMV). These algorithms produce a distributed map of brain activity underlying sustained and transient responses during neuroimaging studies of behavior. On the other hand, there are very few comparative analyses that evaluates the "ground truth detection" capabilities of these methods. The current article evaluates the reliability in estimation of sources of spectral event generators in the cortex using a two-pronged approach. First, simulated EEG data with point dipoles and distributed dipoles are used to validate the accuracy and sensitivity of each one of these methods of source localization. The abilities of the techniques were tested by comparing the localization error, focal width, false positive (FP) ratios while detecting already known location of neural activity generators under varying signal-to-noise ratios (SNRs). Second, empirical EEG data during auditory steady state responses (ASSRs) in human participants were used to compare the distributed nature of source localization. All methods were successful in recovery of point sources in favorable signal to noise scenarios and could achieve high hit rates if FPs are ignored. Interestingly, focal activation map is generated by LCMV and DICS when compared to eLORETA while control of FPs is much superior in eLORETA. Subsequently drawbacks and strengths of each method are highlighted with a detailed discussion on how to choose a technique based on empirical requirements., (Copyright © 2019 Halder et al.)
- Published
- 2019
- Full Text
- View/download PDF
48. Un nuevo enfoque al cálculo del riesgo de rebase en estructuras marinas
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Calafat Garcés, Bartomeu, Gironella Cobos, Xavier, Sánchez-Arcilla Conejo, Agustín, and Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental
- Subjects
puerto ,rebase ,Dique en talud ,nivel medio del mar ,Enginyeria civil::Enginyeria hidràulica, marítima i sanitària::Ports i costes [Àrees temàtiques de la UPC] ,Enginyeria civil::Enginyeria hidràulica, marítima i sanitària [Àrees temàtiques de la UPC] ,Dikes (Engineering) ,cambio climático ,Dics - Abstract
La tesina se desarrolla con la idea de realizar un análisis de sensibilidad del Puerto de Barcelona, obteniéndose la variabilidad en tanto por ciento de la probabilidad de rebase anual, considerando la influencia de los diferentes cambios posibles en el futuro. Se estudian dos formulaciones diferentes para el cálculo del caudal de rebase a diques en talud: Aminti y Franco, y Berenguer y Baonza. Se elige el método que mejor se adapta al Puerto y a las condiciones utilizadas en el estudio.Se analizan las distintas variables influyentes en el rebase (altura de ola, periodo, nivel medio del mar (marea meteorológica, marea astronómica y variación del nivel debido a cambios en la temperatura, dirección incidente del oleaje), y se elige la caracterización que mejor se adapta al caso.
- Published
- 2013
49. Analysis of the performance of SWASH in harbour domains
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Alabart Llinas, Joan, Sánchez-Arcilla Conejo, Agustín, Van Vledder, Gerbrant, and Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental
- Subjects
SWASH ,Enginyeria civil::Enginyeria hidràulica, marítima i sanitària::Ports i costes [Àrees temàtiques de la UPC] ,Blanes ,Onades ,waves ,Dikes (Engineering) ,Ocean waves ,Dics ,harbour - Abstract
Projecte realitzat en el marc d’un programa de mobilitat amb el Faculteit Civiele Techniek en Geowetenschappen de la Technische Universiteit Delft Wave penetration inside harbours has been one the main issues that port planners and engineers have had to deal with in recent years. Wave conditions inside harbours trigger vessel movements; create dynamic loads on port structures and condition harbour exploitation and safety. For this reason in the recent past maritime and port engineers have developed a set of semi-empirical criteria and physical modelling tools to design the layout of breakwaters and other protection structures. Nevertheless, with the development of computers and numerical methods, several models have tried to simulate the propagation of waves inside such restricted domains, affected by multiple competing processes such as diffraction, partial reflection, etc. It is in this framework where SWASH (Simulating WAves till SHore), a model developed by TU Delft, is expected to perform realistic and accurate simulations well beyond the performance limits of other state of the art codes. SWASH solves directly the momentum conservation laws and can deal with dyke geometry and even porosity. It is very suited for simulating non-hydrostatic, free-surface flows, including long-wave generation and short wave propagation. Because of that we shall here evaluate how such a model can simulate the propagation of various types of waves in real harbour cases. The Port of Blanes, located in the Catalan coast with wave measurements available, was chosen as our test case. Previous to the performance of the simulation of the case study, several 1D and 2D simulations were undergone to get acquaint with the model. Furthermore, an exhaustive analysis of the response of SWASH when using porous layers was included. The reason for it was double. On the one hand, to see how the model accounted for porous layers such as dykes and breakwaters. On the other hand, to try to solve the stability problems that the inclusion of those layers may produce. A certain setting when it comes to the numerical discretization of the equations was found to be stable and provide reliable results and used afterwards in the case study of the Port of Blanes. To perform the simulation of the Port of Blanes real case, initially a wave approach with SWAN was performed as the wave data was too far from the entrance of the port. To do so the bathymetry of the surroundings of the port was needed. The output of these simulations was inputted later on in SWASH to do the final stage of the simulation within the port. To do the simulation, an accurate bathymetry of the actual port during the year were the measurements were done was necessary, and a data treatment was done to include the new structures to the out of date bathymetry that could be provided. These simulations accounted for the port structures as porous layers that emulated the partial reflection and transmission phenomena, diffraction and refraction that are present in port domains. The output from the model was then compared to the actual measurements inside the port and a comparison was made. The results show that SWASH can be indeed a rather useful tool for harbour engineering, providing realistic and accurate results. Furthermore, the way the model accounts for porous structures can be considered to be quite flexible and realistic. Finally some conclusions and recommendations for further work in this topic have been drawn. This will set the basis for further development of this numerical tool that could become the cornerstone of port layout planning in the coming years.
- Published
- 2013
50. Análisis de la subpresión en diques verticales
- Author
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Cabayol Lopera, Jaime, Gironella Cobos, Xavier, Garcia Arribas, Oriol, and Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental
- Subjects
Enginyeria civil::Enginyeria hidràulica, marítima i sanitària::Ports i costes [Àrees temàtiques de la UPC] ,Estructures marines ,Onades ,Dikes (Engineering) ,Ocean waves ,Dics ,Offshore structures - Abstract
[ANGLÈS] In the field of port and coastal engineering there are multiple proposals that aim to improve and optimize the offshore structures design. In fact, the complexity of working with the phenomena of nature and its strong randomness requires that past experiences, trial and error, and scale tests, are the methods to expand the technical and improve structures design such as vertical dikes. The purpose of this work is to introduce and develop the behavior of a vertical structure to the main variables that affect its stability, with a special emphasis on uplift component. The uplift is a force that depends on the wave period and design wave height. These two variables, at the same time, are dependent of propagation and breakage. It conditions the applicability of vertical breakwater in certain circumstances, such as shallow waters, since the ratio of stabilizing and destabilizing components is adversely affected due to the low weight of the monolith and generally increasing the uplift forces. Then, reducing the uplift pressure can be a tremendous advantage in the stability of a vertical breakwater. That’s why in this thesis it's an objective to present a range of applicability to a new constructive solution, which is based on maintaining the main characteristics of a floating caisson, which are its simple construction and its buoyancy. This is discussed in various cases of weather wave conditions, the behavior of a vertical breakwater at different drafts. Thus is what the evolution and behavior of the various safety factors that compromise the structure. Once done, there is proposed the operation of the new prototype of floating caisson drilled vertically, which should allow the dissipation of uplift pressure through the flow through these holes. The principal variables which mark the correct operation of this prototype are uplift pressure and weight, therefore, the next step is to quantify relationship between these components which is adequate to ensure stability of the structure. Finally, once known conditions of applicability and performance required in the new floating caisson prototype, is tried to quantify the true relationship between mass and reduction of uplift that can be reached by the new design. This will conclude the feasibility of the constructive solution, since it will know if the minimum performance requirements can be achieved, and if so, the possible optimization that can translate into reduced volume of material or overall improvement in stability. [CASTELLÀ] En el ámbito de la ingeniería portuaria y costera son múltiples las propuestas que pretenden mejorar y optimizar el diseño de las estructuras marítimas. De hecho, la complejidad que supone trabajar con los fenómenos de la naturaleza y su marcada aleatoriedad obliga a que las experiencias pasadas, el ensayo-error y los ensayos a escala real sean los métodos que permitan ampliar la técnica y mejorar el diseño de estructuras tales como los diques verticales. El propósito de esta tesina es, inicialmente, introducir y desarrollar el comportamiento de una estructura vertical ante las principales variables que afectan a su estabilidad, poniendo un especial énfasis en la componente de la subpresión. La subpresión es una fuerza que depende del periodo del oleaje y la altura de ola de diseño. Estas dos variables, a su vez, son susceptibles de la propagación y la rotura. Éste hecho marca sustancialmente la aplicabilidad del dique vertical en ciertas circunstancias, tales como calados poco profundos, ya que la relación entre las componentes estabilizadoras y desestabilizadoras se ve afectada negativamente debido al poco peso del monolito y, generalmente, el aumento de las subpresión. Reducir la subpresión entonces, puede suponer una gran ventaja en la estabilidad de un dique vertical. Es por esto que en esta tesina se pretende presentar un rango de aplicabilidad a una nueva solución constructiva, la cual se basa en mantener las principales características de un cajón flotante, que son su simplicidad constructiva y su flotabilidad. Para ello, se analiza en distintos casos de condiciones climáticas de oleaje, el comportamiento de un dique vertical a distintos calados. De esta manera se encuentra cual es la evolución y comportamiento de los distintos factores de seguridad que comprometen la estructura. Una vez hecho esto, se plantea el funcionamiento del nuevo prototipo de cajón flotante perforado verticalmente, que debe permitir la disipación de la subpresión mediante el flujo a través de dichos agujeros. Las principales variables que marcan el correcto funcionamiento de este cajón son el peso y la subpresión, por lo tanto, el siguiente paso es cuantificar qué relación entre estas componentes es la adecuada para garantizar la estabilidad de la estructura. Por último, una vez conocidas las condiciones de aplicabilidad y rendimiento que requiere el nuevo prototipo de cajón flotante, se intenta cuantificar la verdadera relación entre masa y reducción de subpresión capaz de ser alcanzada por el nuevo diseño. Esto permitirá concluir la viabilidad de la solución constructiva, ya que se podrá saber si los requisitos mínimos de funcionamiento pueden ser alcanzados, y de ser así, la posible optimización que se puede traducir en disminución de volumen de materiales o en mejora global de estabilidad.
- Published
- 2012
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