Graph Signal Processing: Overview, Challenges and Applications

Research in Graph Signal Processing (GSP) aims to develop tools for processing data defined on irregular graph domains. In this paper we first provide an overview of core ideas in GSP and their connection to conventional digital signal processing. We then summarize recent developments in developing basic GSP tools, including methods for sampling, filtering or graph learning. Next, we review progress in several application areas using GSP, including processing and analysis of sensor network data, biological data, and applications to image processing and machine learning. We finish by providing a brief historical perspective to highlight how concepts recently developed in GSP build on top of prior research in other areas.Comment: To appear, Proceedings of the IEE

Extrato de alho melhora a superação da dormência de videiras ‘Niagara Rosada’em regiões subtropicais.

Nas regiões com invernos amenos, normalmente as exigências de frio para a quebra de dormência de gemas de videiras não são atendidas, e apenas os produtos altamente tóxicos CaCN2 e H2CN2 são recomendados na viticultura convencional para quebra de dormência. A proposta deste estudo foi verificar o efeito do extrato de alho na quebra de dormência de videiras ‘Niagara Rosada’, em dois diferentes vinhedos. A dose mais elevada de extrato de alho (70mL L-1)demonstrou ter um grande potencial para a quebra de dormência na produção orgânica, apresentando efeitos similares aos das cianamidas, na quebra de dormência. Este tratamento aumentou a porcentagem de brotação e o número de cachos, antecipou o começo da brotação e reduziu o ciclo entre poda e colheita

A methodology for assessing the urban supply of on-street delivery bays

ABSTRACT: The loading and unloading operations carried out by transport and logistics operators have a strong impact on city mobility if they are not performed correctly. If loading/unloading bays, i.e., delivery bays (DB), are not available for freight vehicle operations, operators may opt to double park or park on the sidewalk where there is no strong enforcement of these laws, with significant impact on congestion. This paper proposes a methodology for verifying and designing the number of delivery bays needed for freight vehicles for not interfere with cars or pedestrians. The methodology consists of two stages: in the first stage, an initial estimation is made using queueing theory. Subsequently, in the second stage, using such tentative scenario, in order to take into account the system stochasticity involving different entities, a discrete event simulation is performed to more realistically verify and upgrade (if necessary) the number of delivery bays to obtain the expected outcomes. The methodology was applied in the inner area of Santander (Spain). The study area was subdivided into 29 zones where the methodology was applied individually. The results indicated that none of these zones currently have an optimal number of delivery bays to satisfy demand. In some zones, there is an excess of delivery bays, although in most of them, there is a deficit which can cause significant impacts on traffic. The method proposed can be an effective tool to be used by city planners for improving freight operations in urban areas limiting the negative impacts produced in terms of internal and external costs

Urban freight transport demand: transferability of survey results analysis and models

ABSTRACT: The present research addresses the issue of data collection, models and methods for urban freight transport demand investigation and the difficulties related to costs and the fact that few data are often available. Then, it becomes important to investigate the transferability of results in order to improve their use and to assess whether the obtained results is dependent on any particular condition, and whether the lessons learnt in one city can be transferred to other cities. The transfer of a previously estimated model to a new application context can reduce or eliminate the need for a large data collection and model development effort in the application context. Therefore, the main goal of the research is to compare the freight transport demand in two European cities (Rome and Santander) in order to highlight which similarities and differences depend on some factors and demonstrates that there are many different patterns of urban distribution that need to be taken into account. The analysis is based on some similar surveys carried out in the cities that are also very different in terms of spatial and economic patterns. Furthermore, the available surveys in Rome and Santander have been the basis for the calibration also in Santander of a modelling system for urban freight demand forecast set up in Rome. In such a way, the analysis of model and parameter transferability is also investigated

Influence of Different Geometrical Parameters

Part of the work was undertaken during a short-term scientific stay by the first author at the Faculty of Engineering (University of Porto) in 2021, with the financial support provided by Programa Propio de I+D+i 2021 de la Universidad Politécnica de Madrid. This work is part of the R&D&I Project PID2020-112954RA-I00 funded by MCIN/AEI/10.13039/501100011033. The authors gratefully acknowledge Fundação para a Ciência e Tecnologia (FCT-MCTES) for the financial support of the Laboratório Associado de Energia, Transportes e Aeronáutica (LAETA) by the project UID/EMS/50022/2020 and the Research and Development Unit for Mechanical and Industrial Engineering (UNIDEMI) by the projects UIDB/00667/2020 and UIDP/00667/2020. Publisher Copyright: © 2024 by the authors.In the present work, single- and double-dowel joints following different geometric configurations are experimentally and numerically investigated to derive the splitting behaviour of beech wood (Fagus sylvatica L.), one of the most widespread hardwood species in Europe for structural purposes. The influence of the spacing between dowels, their distance to the supports, and the slenderness of the beams is analysed. The correlation of the experimental failure loads with those predicted numerically by cohesive zone finite element-based models using the fracture properties of the species is discussed. The experimental results are also compared with those obtained from the normative expression included in Eurocode 5 and two other design models reported in the literature. The splitting failure loads predicted by both the analytical and numerical models were found to be conservative, the latter being closer to the experimental values.publishersversionpublishe

Shear traction‐separation laws of European beech under mode II loading by 3D digital image correlation

Funding Information: Part of the work was undertaken during a short-term scientific stay by the first author at the Faculty of Engineering (University of Porto) in 2021, with the financial support provided by Programa Propio de I+D+i 2021 de la Universidad Politécnica de Madrid. The work is part of the R&D&I Project PID2020-112954RA-I00 funded by MCIN/AEI/10.13039/501100011033. The authors gratefully acknowledge also Fundação para a Ciência e a Tecnologia (FCT-MCTES) for the financial support of the Laboratório Associado de Energia, Transportes e Aeronáutica (LAETA) by the project MCIN/AEI/10.13039/501100011033 and the Research and Development Unit for Mechanical and Industrial Engineering (UNIDEMI) by the project UIDB/00667/2020. Publisher Copyright: © 2022, The Author(s).An experimental and numerical study on mode II fracture behaviour of European beech (Fagus sylvatica L.) in the RL and TL crack propagation systems is performed. It is a hardwood species that has attracted increasing interest for structural use in Europe in recent years. Three-point end notched flexure tests are performed. The R-curves of both crack propagation systems are obtained, from which the critical strain energy release rate (GIIc) is derived by applying the compliance-based beam method. This data reduction scheme avoids crack length monitoring during its propagation, which is an advantage in wood. Using a direct method, the shear traction‐separation laws in mode II loading are determined. Full field displacements around the crack tip are monitored by 3D digital image correlation technique, and the crack tip shear displacements are analysed. The proposed method is numerically validated by finite element analysis. Cohesive zone models are developed implementing a shear traction–separation law with exponential damage evolution zone and the average value of the experimental elastic and fracture properties. The numerical results for the different properties including upper and lower limits represent well the experimental data.publishersversionepub_ahead_of_prin

Buccal fat pad removal to improve facial aesthetics : an established technique?

Buccal fat pad (BFP) is a singular structure between the facial muscles. Its removal may enhance the zygomatic prominences resulting in an inverted triangle of beauty. Objective: The aim of this study was to perform a systematic review of literature about BFP removal for facial aesthetic improvement. In order to answer the following research question: What are the indications, complication types and rates, surgical techniques and outcomes of the technique? The initial search in Pubmed, Scopus, and Cochrane databases recognized 220 articles. The final review included eight of them. None of the included studies were clinical trials. BPF removal was performed by intraoral incision or associated with the face lift procedure. In 71 patients submitted to the procedure and evaluated about complications, only 8.45% presented minor complications. Parotid duct and facial nerve injuries were not found. No study evaluated facial aging and long-term effects, therefore the harmless effect of the procedure to those features is not clear. Although it is not a novel procedure, there is a lack of information about long-term outcomes. Thus, controlled clinical studies should be performed to achieve adequate clinical evidence of those aspects

Evaluation of R-curves and cohesive law in mode I of European beech

This work addresses the determination of the cohesive laws in Mode I and tangential–longitudinal (TL) crack propagation system of Fagus Sylvatica L. This species is one of the ever-growing and most widely used hardwood species in Europe for engineered timber products. Double Cantilever Beam (DCB) tests are performed. The strain energy release rate ( G I) is derived from the R-curves by applying the Compliance-Based Beam Method (CBBM), which has the advantage of not requiring the measurement of the crack length during propagation, but only the global load–displacement curves. The cohesive law of the material is determined from the relationship between G I, and the crack tip opening displacement (CTOD) monitored for each specimen using Digital Image Correlation (DIC). Numerical finite element models are developed by implementing the average cohesive law through Cohesive Zone Models (CZM). An average G I value of 0.46 kJ / m 2 is obtained for this species. The numerical load–displacement curves are consistent with the experimental results, which demonstrates the suitability of the method for the identification of the cohesive laws in beech. The fracture properties obtained are essential in the development of advanced and reliable numerical models in timber engineering design using this species.publishersversionpublishe

MAPEAMENTO DE VULNERABILIDADE DOS AQUÍFEROS DUNAS, BARREIRAS E FISSURAL NA PORÇÃO NORTE DO COMPLEXO INDUSTRIAL E PORTUÁRIO DO PECÉM, ESTADO DO CEARÁ

O presente trabalho apresenta a avaliação da vulnerabilidade natural dos aquíferos Dunas, Barreiras e Fissural na porção norte do Complexo Industrial e Portuário do Pecém (CIPP), estado do Ceará (Brasil), por meio dos métodos DRASTIC e GOD. Teve por objetivo gerar subsídios para o planejamento ambiental, com vistas à gestão das águas subterrâneas locais. Os referidos métodos trabalham com um número de parâmetros distintos, sendo o DRASTIC mais robusto, restritivo e preciso. O método DRASTIC apresentou cinco classes de vulnerabilidade, caracterizando a maior parte da área como de vulnerabilidade alta (25%) ou muito alta (24,7%). O método GOD apresentou duas classes de vulnerabilidade: vulnerabilidade moderada (59%) e vulnerabilidade alta (41%). Em ambos os métodos o aquífero Dunas representa o meio mais vulnerável, onde justamente estão alocadas uma siderúrgica e áreas de ampliação urbana. Em vista disto, ações para a prevenção de possíveis contaminações devem ser implementadas. O meio fissural e o aquífero Barreiras, apesar de menos vulneráveis, devem igualmente merecer atenção e monitoramento. O trabalho apresenta-se como ferramenta aos setores públicos e privados para a gestão mais eficaz das águas subterrâneas locais

A further investigation of the cytochrome b5–cytochrome c complex

J Biol Inorg Chem (2003) 8: 777–786The interaction of reduced rabbit cytochrome b5 with reduced yeast iso-1 cytochrome c has been studied through the analysis of 1H–15N HSQC spectra, of 15N longitudinal (R1) and transverse (R2) relaxation rates, and of the solvent exchange rates of protein backbone amides. For the first time, the adduct has been investigated also from the cytochrome c side. The analysis of the NMR data was integrated with docking calculations. The result is that cytochrome b5 has two negative patches capable of interacting with a single positive surface area of cytochrome c. At low protein concentrations and in equimolar mixture, two different 1:1 adducts are formed. At high concentration and/or with excess cytochrome c, a 2:1 adduct is formed. All the species are in fast exchange on the scale of differences in chemical shift. By comparison with literature data, it appears that the structure of one 1:1 adduct changes with the origin or primary sequence of cytochrome b5