Percorrer por autor "Gomes, Ricardo"
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- Analysis and Simulation of Drainage Capacity of Urban Pipe NetworkPublication . Gomes, Ricardo; Vellando, P.; Sousa, J.; Sá Marques, J.; Muranho, J.In the last decades the urban area of Leiria (Portugal) has spread quickly and the impervious surfaces increased significantly, mostly because of the type of pavements used (asphalt and Portuguese cobblestone) and the area occupied by buildings. One of the major problems is related to the recurrent floods in Leiria’s downtown during periods of higher rainfall intensity, which affect the economic activities, the environment and the residents’ lives. The urban area benefits from a large drainage network, but in some zones it has low performance, due to the degradation of the infrastructure and the successive located interventions occurred in the last decades (for network expansion and rehabilitation works). To minimize the flooding impacts in Leiria’s downtown, the municipality intends to build an underground pipeline (a length of 1.5 kilometres, with a 2.0 metres diameter and 0.2% slope) to convey the runoff by gravity from Leiria’s downtown to the river. This paper presents an integrated study of the urban catchment and the drainage network capacity using the Storm Water Management Model (SWMM). This study included the analysis of the solution for different rainfall intensities (corresponding to different return periods) to assess its performance and, when required, suggest additional recommendations.
- Assessing the influence of uncertainty in land cover mapping and digital elevation models on flood risk mappingPublication . Gonçalves, Luísa M.S.; Fonte, Cidália C.; Gomes, RicardoThis paper proposes an approach to assess the influence of the uncertainty present in the parameters dependent on the land cover and elevation data over the peak flow values and the subsequent delineation of flooded areas. The proposed approach was applied to produce vulnerability and risk maps that integrate uncertainty for the urban area of Leiria, Portugal. A SPOT-4 satellite image and DEMs of the region were used. The peak flow was computed using the Soil Conservation Service method and HECHMS, HEC-RAS, Matlab and ArcGIS software programs were used. The analysis of the results obtained for the presented case study enables the identification of the order of magnitude of uncertainty associated to the watershed peak flow value and the identification of the areas which are more susceptible to flood risk to be identified.
- Different Design Criteria for District Metered Areas in Water Distribution NetworksPublication . Gomes, Ricardo; Sousa, Joaquim; Muranho, João; Marques, Alfeu SáIn this paper the influence of several factors to establish a suitable DMA design is considered using an adaptation of the methodology previously developed by Gomes [1]. This methodology is based on graph theory concepts (Floyd-Warshall algorithm) and some user-defined criteria to establish the number and size of DMAs and uses a Simulated Annealing algorithm to identify the most appropriate number and location of metering stations, boundary valves and network reinforcement/replacement needs along the project plan. Different design criteria are applied to a case study and the results obtained by the methodology are used to draw some conclusions. © 2015 The Authors.
- District Metered Areas Design Under Different Decision Makers’ Options: Cost AnalysisPublication . Gomes, Ricardo; Marques, Alfeu S. A.; Sousa, JoaquimWater loss is a big challenge for water supply companies worldwide, and the Water Network Partitioning (WNP) is an excellent tool for water loss management–particularly in the current difficult economic and financial conditions. WNP is a recent research line and consists in dividing the water distribution network into smaller zones called District Metered Areas (DMAs) with one (or more, in exceptional cases) supply point, to reduce the network complexity and/or allow pressure management. Since there are several possible future scenarios, such as the water demand and/or the infrastructure degradation forecasts, which may have different impacts on the hydraulic behaviour, in this paper a computational application, based on an optimization model, is proposed to achieve a compromise between robustness required for the DMAs design (using a baseline scenario) and different decision makers’ options (using other scenarios with a lower “probability” of occurrence), to reduce the total cost. The objective function reflects the minimization of the squared deviations between the total cost of the DMAs design and the minimum cost for each scenario forecasted for the project plan, multiplied by the weight or “probability” of occurrence for each of the scenarios. The performance of the computational application is illustrated with a case study, and the results are encouraging.
- Estimation of the benefits yielded by pressure management in water distribution systemsPublication . Gomes, Ricardo; Marques, Alfeu Sá; Sousa, JoaquimThe occurrence of water losses in Water Distribution Systems is inevitable. Knowing that most of the real losses take place in distribution mains and in service connections, the methodology proposed in this paper is based on several leakage-assessment approaches from literature and on water distribution network modeling. This allows assessment of the benefits that can be achieved by pressure management in Water Distribution Systems, particularly in terms of water production reduction. Moreover, this approach can be useful for cost benefit analysis to help establish the level after which there is no more economic interest in reducing water losses (Economic Level of Leakage). Finally, the results from hypothetical case studies are presented and discussed, assuming the installation of Pressure Reducing Valves at District Metered Areas entry points.
- Golf-Putting Performance in Skilled Golfers at Different Distances to the HolePublication . Dias, Gonçalo; Couceiro, Micael; Mendes, Pedro; Gomes, Ricardo; Mendes, Rui; Vaz, Vasco; Martins, Fernando; Gama, José; Castro, Maria AntónioGolf putting occurs under highly variable conditions. Therefore, adapting to different putting distances is a challenge that the golfer faces and understanding the variables underlying performance in this task is important. The main objective of this study was to analyse the golf-putting performance in skilled golfers at different distances to the hole. Fourteen highly skilled golfers, adult male and right-handed (41.5 ± 13.2 years with an average handicap of 2.3 ± 1.7) performed the golf putting on a natural grass green, completing a total of 120 randomly ordered trials, 30 trials at each of the four different practice conditions (1, 2, 3, and 4 m away from the hole). A smart engineered putter (InPutter) was used as the data acquisition instrument to record several process variables at 100 Hz. Results indicated that golf-putting distances constrained movement organisation variables in specific ways. For example, as the distance to the hole changes, so do the informational constraints, shaping how a golfer needs to regulate performance. We concluded that the effects of different golf-putting distances required the implementation of functional solutions uniquely adjusted to each player. Furthermore, the perception that the player withdrew from the properties of the context (e.g., distance to the hole) was important to adapt the golf-putting process variables (e.g., amplitude and duration of the movement, among others). All these factors led to a decisive influence on how the golfer hit the ball and adjusted his performance. A major implication of developing a better understanding of the role of performance in golf putting is that coaches and players should allow functional movement behaviours to emerge during practice.
- Identification of the optimal entry points at District Metered Areas and implementation of pressure managementPublication . Gomes, Ricardo; Marques, Alfeu Sá; Sousa, JoaquimNowadays, the implementation of pressure management in District Metered Areas (DMAs) is considered one of the most effective tools for leakage control, particularly in large networks and in systems with deteriorated infrastructures and with high pressure. The goal of the methodology proposed in this paper is to identify the optimal entry points at DMAs, determine the network needs in terms of reinforcement/replacement, and fix both the location and settings of different types of Pressure Reduction Valves (PRVs) for leakage control. This methodology is based on an optimisation model, which is solved by a Simulated Annealing algorithm, and the solutions obtained always fulfil the minimum pressure requirements for the network. The objective function comprises the total cost of the DMAs implementation and the economic benefits that can be achieved by pressure management. Finally, the results for two case studies are presented and discussed.
- Information Security and Cybersecurity Management: A Case Study with SMEs in PortugalPublication . Antunes, Mário; Maximiano, Marisa; Gomes, Ricardo; Pinto, DanielInformation security plays a key role in enterprises management, as it deals with the confidentiality, privacy, integrity, and availability of one of their most valuable resources: data and information. Small and Medium-sized enterprises (SME) are seen as a blind spot in information security and cybersecurity management, which is mainly due to their size, regional and familiar scope, and financial resources. This paper presents an information security and cybersecurity management project, in which a methodology based on the well-known ISO-27001:2013 standard was designed and implemented in fifty SMEs that were located in the center region of Portugal. The project was conducted by a business association located at the center of Portugal and mainly participated by SMEs. The Polytechnic of Leiria and an IT auditing/consulting team were the other two entities that participated on the project. The characterisation of the participating enterprises, the ISO-27001:2013 based methodology developed and implemented in SMEs, as well as the results obtained in this case study, are depicted and analysed in the paper. The attained results show a clear benefit to the audited and intervened SMEs, being mainly attested by the increasing of their information security management robustness and collaborators’ cyberawareness.
- Modelação matemática como ferramenta de gestão e exploração de sistemas de distribuição de águaPublication . Gomes, RicardoA redução das perdas em sistema de distribuição de água, até níveis considerados economicamente viáveis e tecnicamente aceitáveis, constitui um dos principais objectivos para a maior parte das Entidades Gestoras de serviços públicos de abastecimento de água, tendo em vista alcançar a médio e longo prazo a sustentabilidade do serviço prestado. Esta realidade tem vindo a ser evocada a nível internacional, e, em Portugal, está consagrada no PEAASAR 2007-2013, que fixa a necessidade de reduzir as perdas de água para valores inferiores a 20% (Objectivo operacional 2). Neste contexto, a implementação de Zonas de Medição e Controlo (ZMC), sectorização do sistema em subsistemas de menor dimensão, pode dar um excelente contributo para atingir esses objectivos. Embora a sectorização da rede não permita directamente o controlo das perdas, acaba por ser um instrumento crucial no que concerne à sua detecção, caracterização e distribuição espacial. Além disso, facilita a implementação de estratégias activas de controlo de perdas, o estabelecimento de prioridades de intervenção na rede, a gestão das pressões ao longo do dia em função dos consumos, o controlo da facturação e monitorização de parâmetros relacionados com a qualidade da água. Partindo deste pressuposto, duas novas metodologias são propostas neste trabalho como ferramentas de gestão e exploração de sistemas de distribuição de água. Sabendo que a ocorrência de perdas de água, na sua grande maioria, ocorre na rede de distribuição nos ramais de ligação, a primeira metodologia proposta baseia-se num modelo matemático de simulação hidráulica e nas melhores práticas internacionais para gestão das perdas de água através da redução da pressão à entrada do sistema ou subsistema (mais comum na prática). Esta metodologia permite estimar os benefícios económicos directos originados pela redução da pressão na rede, particularmente em termos da redução da produção de água. No entanto, outros benefícios, como por exemplo, a redução da frequência de roturas, redução dos custos de controlo activo de fugas, a redução do consumo de energia e a redução do número de reclamações de utilizadores, podem ser adicionados. Além disso, pode ser ainda usada para definir o nível económico de perdas, ou seja, o nível a partir do qual não haverá mais interesse económico em reduzir as perdas de água. A segunda metodologia proposta neste trabalho está relacionada com o estudo de viabilidade e sustentabilidade do projecto de sectorização de redes de distribuição de água, incluindo a gestão da pressão ao longo da rede e durante o horizonte de projecto. Além disso, pode ser usada para planear os investimentos necessários em diferentes momentos, durante o horizonte de projecto, de acordo com as reais necessidades e os recursos financeiros da Entidade Gestora. Baseia-se na teoria dos grafos (algoritmo de Floyd-Warshall) para definir a geometria ou limites entre ZMC, e num algoritmo de optimização (baseado na meta heurística Simulated Annealing) ligado a um simulador hidráulico em regime quase-permanente para estudar as condições de fronteira entre ZMC, tal como o reforço da capacidade de transporte da rede e a gestão da pressão durante o horizonte de projecto. Para testar o desempenho das duas aplicações computacionais desenvolvidas, no final deste documento apresentam-se vários estudos de caso e discutem-se os resultados obtidos.
- Using Secure Multi-Party Computation to Create Clinical Trial CohortsPublication . Borges, Rafael; Ferreira, Bruno; Antunes, Carlos Machado; Maximiano, Marisa; Gomes, Ricardo; Távora, Vitor; Dias, Manuel; Bezerra, Ricardo Correia; Domingues, Patrício; Antunes, Carlos MachadoThe increasing volume of digital medical data offers substantial research opportunities, though its complete utilization is hindered by ongoing privacy and security obstacles. This proof-of-concept study explores and confirms the viability of using Secure Multi-Party Computation (SMPC) to ensure protection and integrity of sensitive patient data, allowing the construction of clinical trial cohorts. Our findings reveal that SMPC facilitates collaborative data analysis on distributed, private datasets with negligible computational costs and optimized data partition sizes. The established architecture incorporates patient information via a blockchain-based decentralized healthcare platform and employs the MPyC library in Python for secure computations on Fast Healthcare Interoperability Resources (FHIR)-format data. The outcomes affirm SMPC’s capacity to maintain patient privacy during cohort formation, with minimal overhead. It illustrates the potential of SMPC-based methodologies to expand access to medical research data. A key contribution of this work is eliminating the need for complex cryptographic key management while maintaining patient privacy, illustrating the potential of SMPC-based methodologies to expand access to medical research data by reducing implementation barriers.