Artigos de Revista

Considering the growing volume of information and services available on the web, it has become essential to provide websites and applications with tools, such as recommender systems, capable of helping users to obtain the information and services appropriate to their interests. Due to the complexity of web adaptation and the ability of multi-agent systems to deal with complex problems, the use of multi-agent approaches in recommender systems has been increasing. In the present work, we make a thorough review of the use of multi-agent-based recommender systems. The review shows the diversity of applications of multi-agent systems in recommender systems, namely on what concerns the diversity of domains, different types of approaches and contribution to the performance improvement of the recommender systems.

This paper presents a multi-criteria decision support methodology for selection and prioritization of rehabilitation intervention in urban water infrastructures considering performance, cost and risk and a long-term perspective. This methodology is divided into three main stages: problem identification, structuring and evaluation. Problem structuring, a crucial stage for the outcomes, includes identifying objectives, selecting scenarios within the analysis period, defining problem options and the problematic type. Problem evaluation includes the selection of assessment metrics, selection of the aggregation method, application of the method and sensitivity and robustness analysis and final recommendations. The methodology is applied to a real case study of a water distribution system, being the different stages presented in detail and obtained results discussed.

Climate trends suggest an increase in the frequency of intense rainfall events and the aggravation of existing conditions in terms of flooding in urban areas. In coastal areas, conditions are aggravated by coexistence with coastal overtopping. Flood risk control is complex, and the interdependencies among the services and sectors in urban areas imply the need for adoption of approaches that embrace the interplay between service providers to ensure critical urban functions. Flooding incorporates several hazards. Assessment of resilience to multiple hazards in complex environments benefits from integrated and multi-sectoral approaches. A common constraint resides in the limited data and tools available for undertaking these complex assessments. This paper proposes a risk-based methodology to assess urban areas

Depois de uma introdução ao artigo, onde se salienta o respetivo enquadramento na série editorial, que remata, em termos de textos de conteúdo estruturados, desenvolve-se um reflexão sobre como apoiar a proposta de uma renovada Habitação de Interesse Social Portuguesa (HISP), que aproveite o melhor que se fez nos cerca de 100 anos de história da HISP, com relevo para os numerosos casos de referência concretizados no último quarto de século de promoção ativa de Habitação a Custos Controlados (HCC) apoiada pelo INH/IHRU, e tirando-se partido de um acompanhamento destes conjuntos, que tem sido já possível, em alguns casos, ao longo de uma sua já significativa

Depois de uma introdução ao artigo, onde se salienta o respetivo enquadramento na série editorial, que é também minimamente apresentada, avança-se numa reflexão sobre como apoiar a proposta de uma renovada Habitação de Interesse Social Portuguesa (HISP), que aproveite o melhor que se fez nos cerca de 100 anos de história da HISP, com relevo para os numerosos casos de referência concretizados no último quarto de século de promoção ativa de Habitação a Custos Controlados (HCC) apoiada pelo INH/IHRU.Abordam-se, em seguida, os aspetos de reflexão prospetiva sobre o que poderá ser a nova HISP de um modo mais sistemático, em termos dos diversos níveis físicos residenciais e urbanos considerados: vizinhança alargada; vizinhança próxima ou de proximidade; edifício multifamiliar; edifício unifamiliar; habitação. Sempre que é considerado pertinente discute-se, também, a aplicação de variadas e inovadoras tipologias, designadamente, em termos de edifícios multifamiliares.Em cada nível físico a abordagem é realizada através de uma reflexão qualitativa ampla e diversificada, utilizando-se uma grelha qualitativa que foi, anteriormente, devidamente estudada e discutida; em todo este desenvolvimento aproveita-se, ao máximo, o acompanhamento de muitos conjuntos de HISP, que tem sido possível, em alguns casos, ao longo de uma sua já significativa

This paper presents a study of run-up/overtopping over a smooth impermeable dike with promenade using 2D and 3D mesh-based and mesh-free numerical models and results from 2D physical modelling for strong energetic incident waves. These waves induce plunging wave breaking and a complex water/air mixture turbulent flow before overtopped the dike, a challenging configuration for numerical models. The analysis is structured in two phases: (i) evaluates the results of 2D numerical and physical models for run-up and overtopping; (ii) compares qualitatively the results of 3D numerical models for overtopping over a dike with promenade between groins located in front of a slope beach. The results indicate that the main differences obtained in run-up and overtopping are due to differences in wave generation and active absorption systems used in physical and numerical models and in turbulent models used by the numerical models. These differences lead to changes on incident wave height and on wave breaking and, consequently, on reflection, run-up and overtopping over the structure. For 3D simulation, even if larger discrepancies were found on overtopping along the dike, mean wave overtopping discharge and water flow height at the crest of the groin head show a similar order of magnitude.

Earthquake damage in historic masonry buildings is generally caused by the collapse of individual portions thatbecome detached form the structure and fail by overturning. These mechanisms are mainly governed by thediscrete nature and geometry of the block units. Analyses based on explicit micro-modelling in which each blockis considered separately are therefore of increasing importance. This paper offers a robust tool for the seismicassessment of masonry structures under either, quasi-static or dynamic loading. Algorithms for performing dynamicpulses and pushover analyses through the Discrete Element Method are developed and described, takinginto account the actual discrete nature and geometry of masonry. A numerical procedure is proposed thatautomatically detects the collapse mode and follows the evolution of the analysis until collapse. The implementedmethod is able to give a reliable estimate of the expected failure mechanism, providing the seismicacceleration required to trigger the motion and the ultimate displacement beyond which the collapse occurs.Finally, the implemented algorithms are applied to two case studies and the results are compared with thetraditional analysis based on rigid-block kinematics to outline the features and potentialities of the proposedapproach.

Night natural ventilation systems have been receiving increased attention in recent years because of their energy saving potential and environmental protection when used in passive instead of active cooling. A novel system recently proposed for cooling the building concrete slab is studied numerically in the present work. The system relies only on night ventilation as a means for cooling down the structure of the building. It consists of a new type of suspended ceiling with a peripheral gap between it and the walls combined with the positioning of the air supply and extraction grilles between the ceiling slab and the suspended ceiling. This study focuses on the use of Computational Fluid Dynamics (CFD) to predict the airflow and thermal performance of this strategy for an office room. Ansys-Fluent is used to perform the calculations both for a reduced and a full-scale room. Transient simulations were performed for a period of 24 h and the predictions for the reduced-scale model were validated by experiments under different operating conditions. The results show that the mathematical and numerical models provide satisfactory predictions of the temperature evolution in the reduced-scale model, allowing the analysis to be extended for full scale. The predictions for the office room at full scale confirm the effectiveness of the proposed cooling technique, revealing that the air peak temperature during the day is lower, as well as the temperature of the slab and the temperature of the air in the plenum during the night.

Este ensaio aborda a (re)invenção do espaço urbano a partir de lógicas cocriativas e, em específico, contempla o recurso feito a matéria azulejar no âmbito deste intuito. Por um lado, tendo por referência o Projeto Europeu C3Places, discute o potencial contributo da cocriação enquanto modus operandi do produzir espaço público urbano. Por outro lado, a partir de uma perspetiva exploratória, salienta determinados aspetos observados no decorrer de mapeamento de experiências cocriativas – em Portugal e no Brasil – que, em comum, recorrem ao azulejo na (re)invenção do espaço público. A reflexão destaca o potencial das iniciativas cocriativas no incrementar de sensibilidades coletivas com o património e o ambiente urbano. Observando que as mesmas não advêm de grandes ações, mas naquelas de menor âmbito, localizadas e de cunho colaborativo. O uso feito da matéria azulejar para a dinamização de ações coletivas e colaborativas é salientado. O que permite observar que, por um lado, a partir de uma lógica de continuidade-renovação, o recurso ao azulejo, viabiliza a invenção de património. Por outro lado, a aplicação de azulejo em espaço público protagoniza uma maior atenção coletiva com o ambiente urbano. A cocriação transformativa do espaço infere uma ligação à esfera pública, o que colabora para refletir sobre o papel que pode ter no incremento de práticas sociais mais envolvidas com os lugares urbanos e sensíveis à memória, ao património e ao ambiente.