Utility-driven assessment of anonymized data via clustering

In this study, clustering is conceived as an auxiliary tool to identify groups of special interest. This approach was applied to a real dataset concerning an entire Portuguese cohort of higher education Law students. Several anonymized clustering scenarios were compared against the original cluster solution. The clustering techniques were explored as data utility models in the context of data anonymization, using k-anonymity and (ε, δ)-differential as privacy models. The purpose was to assess anonymized data utility by standard metrics, by the characteristics of the groups obtained, and the relative risk (a relevant metric in social sciences research). For a matter of self-containment, we present an overview of anonymization and clustering methods. We used a partitional clustering algorithm and analyzed several clustering validity indices to understand to what extent the data structure is preserved, or not, after data anonymization. The results suggest that for low dimensionality/cardinality datasets the anonymization procedure easily jeopardizes the clustering endeavor. In addition, there is evidence that relevant field-of-study estimates obtained from anonymized data are biased.info:eu-repo/semantics/publishedVersio

Air flow exchange velocity of urban canyon cavities due to thermal spatial differences

In this paper, the air exchange velocity between the urban canyon cavity and the air layer above roof level is quantified, using a two-dimensional k-ε model, and correlated with the air cavity mean temperature, for two cases: leeward and downward wall heating. The spatial thermal differences are evaluated by assuming a wall temperature higher than the air temperature, with this difference ranging between 0 and 16 K. The undisturbed wind velocity above the roof level is varied from 1 to 6 ms-1 and the canyon aspect ratio is 1.5, which corresponds to a skimming flow regime. The model predicts two situations, which correspond to air flow regimes where one or two eddies are formed, respectively: (a) for high wind speed, the air inside the cavity is negligible affect by the buoyancy effect and the air exchange velocity linearly increases with the increase of wind velocity; (b) for low wind speed, when the buoyancy forces are stronger than the wind induced forces, the air exchange velocity is not a linear function with the wind velocity. The transition wind velocity between (a) and (b) is a function of the wall-air temperature difference. The situation of windward heated wall and two eddies air flow regime is the most favorable to extract heat from the cavity. On the contrary, the heated air is hardly extracted from the cavity when only the wind induced eddy is predicted and windward wall is heated. In this situation an increase of 10 K on the wall temperature increases by 1 K the in-cavity air temperature

Processamento de fluxos de dados em arquitecturas híbridas CPU/Intel® Xeon Phi

O processamento de fluxos de dados (mais conhecido pela sua designação algo-saxónica Stream processing) reflete um paradigma de computação em paralelo, cujos conceitos possibilitam a implementação de soluções que funcionam sobre grandes quantidades de dados que são produzidos em alta frequência e que têm de ser processados rapida- mente. Este paradigma é essencial para implementação de sistemas de monitorização, nomeadamente na bolsa, na saúde e na prevenção de fraude. Para suportar este modelo de computação em paralelo é necessário hardware com elevada capacidade de proces- samento paralelo, como por exemplo, computadores com muitos núcleos, ou clusters de computadores ou de GPUs. No entanto, a utilização destas plataformas para processa- mento de fluxos de dados levanta alguns problemas, como a latência da transmissão de dados entre os nós de um cluster, ou ausência de sincronização global em GPUs (o que implica transferências de controlo entre o GPU e o CPU). Uma outra plataforma hardware para computação em paralelo é o co-processador Intel Xeon Phi, desenvolvido pela Intel, e baseado na arquitetura MIC. O Intel Xeon Phi é capaz de executar código x86, o que possibilitou que alguns sistemas de processamento de fluxos de dados, como o Intel Threading Building Blocks Flow Graph, fossem portados para execução no co-processador. No entanto, não existe nenhuma proposta que tire partido das características de um nó heterogéneo CPU(s)/Xeon Phi, no seu todo. Nesse contexto, o objetivo desta dissertação é propor um sistema com a capacidade de executar um grafo de processamento de fluxos de dados em nós heterogéneos CPU(s)/Xeon Phi. Para tal, propõe-se a extensão da biblioteca Intel TBB FG, de forma a suportar esse novo tipo de ambientes com um impacto mínimo no seu modelo de programação. A pro- posta foi avaliada através da comparação de processamento de fluxo utilizando só o CPU com a utilização CPU/Xeon Phi, para medir os ganhos esperados. Nessas comparações fo- ram detectadas situações, onde a segunda alternativa tinha grandes benefícios (speedups) sobre a outra.Stream processing, also known as data-flow processing, is a parallel computing paradigm, whose concepts enable the implementation of solutions that handle large volumes of data generated at high rates and, thus, must be swiftly processed. This paradigm is widely used in the implementation of monitoring systems, namely in the stock market, health and fraud detection. The deployment of a stream processing system requires massively parallel hardware, such as clusters or graphics processing units (GPUs). However, the use of these platforms (for processing data flows) raises several issues such as the latency of intra-node communication in clusters, to the lack of global synchronization in GPUs (which implies control transfers between the GPU and the host). The Intel Xeon Phi is a many-core processor based on Intel’s Many Integrated Core (MIC) architecture and, thus, able to run x86 binary code. This property spawned the porting of some stream processing libraries to Intel Xeon Ph, such as Intel’s Threading Building Blocks Flow Graph. However, there is no solution able to harness the individual characteristics and combined computing power CPUs and Intel Xeon Phi co-processors of hybrid CPU(s)/Intel Xeon Phi nodes. In this context, the goal of this thesis is to propose a stream processing system capable of running on hybrid CPU(s)/Intel Xeon Phi nodes. For that purpose, we extended Intel’s Threading Building Blocks Flow Graph library with the ability to run on this hybrid environment, with minimal impact on the library’s programming model. Our proposal was evaluated from a performance perspective by comparison with stream processing on a conventional shared-memory multicore system. The results show significant performance boosts, specially when task granularity and work load increases

Inspædia : uma rede de inteligência colaborativa inspiradora

El artículo presenta un proyecto de doctorado en Diseño, en el ámbito en el cual se desarrolló el modelo de una nueva plataforma que designamos Inspædia. Se trata de una red de inteligencia colaborativa que podrá ser usada por cualquier persona, en cualquier lugar, con el propósito de generar procesos de innovación y de diseño, con acceso desde cualquier superficie interactiva con conexión a Internet. Será democrática, confiable, integradora, sin ideología, facilitadora de intercambio, colaborativa, amigable, centrada en los usuarios, no jerárquica, no lineal, inspiradora de aprendizaje. Será un repositorio dinámico de contenidos multimedia interrelacionados, un ágora para observadores permanentes, flâneurs elaboradores de contenidos involucrados en procesos de innovación y diseño. Abrirse a nuevos contenidos y/o nuevas relaciones entre contenidos

A cross-sectional study on nurses' attitudes towards physical restraints use in nursing homes in Portugal

© 2021 The Authors. Nursing Open published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.Aim: To explore nurses' opinions regarding restraint measures and attitudes towards physical restraints use in nursing homes. Design: Cross-sectional study. Methods: Nursing staff of 33 Portuguese nursing homes was asked to complete the Portuguese version of the Maastricht Attitude Questionnaire (MAQ), an instrument on attitudes regarding physical restraints (reasons, consequences and appropriateness of restraint use) and opinions about restraint measures (restrictiveness and discomfort). Descriptive statistics and bivariate analysis were performed. Results: Data from 186 nurses were included in the analysis. Overall, nurses expressed neutral to moderately positive attitudes towards physical restraints usage. Nurses with longer professional experience reported a more positive attitude regarding the appropriateness of restraint use in their clinical practice. Wrist and ankle restraints were the measures that nurses reported feeling most uncomfortable using, and the most restrictive. Bilateral bedrails were globally assessed as a slightly restrictive measure and nurses reported not feeling uncomfortable using them.The first author has an individual doctoral scholarship funded by Fundação para a Ciência e Tecnologia FCT, grant reference SFRH/BD/130970/2017info:eu-repo/semantics/publishedVersio

Price forecasting in the day-ahead Iberian electricity market using a conjectural variations Arima model

Price forecast is a matter of concern for all participants in electricity markets, from suppliers to consumers through policy makers, which are interested in the accurate forecast of day-ahead electricity prices either for better decisions making or for an improved evaluation of the effectiveness of market rules and structure. This paper describes a methodology to forecast market prices in an electricity market using an ARIMA model applied to the conjectural variations of the firms acting in an electricity market. This methodology is applied to the Iberian electricity market to forecast market prices in the 24 hours of a working day. The methodology was then compared with two other methodologies, one called naive and the other a direct forecast of market prices using also an ARIMA model. Results show that the conjectural variations price forecast performs better than the naive and that it performs slightly better than the direct price forecast

Glass furnace technology for reduced emissions based on advanced control and monitoring

This paper reports an advanced furnace viewing sensor for regenerative U-flamed glass furnaces, which is demonstrated in a 40 t /d pull furnace of tableware glass burning thick fuel oil. The system processes digitized images from the combustion Chamber a n d uses information related to the geometric features of the flame for monitoring furnace Performance. The procedure is shown t o be able to reduce NOₓ, levels by u p to 20 %, by means of adequate control of the fuel atomization air

A spatially-resolved material flow model: of the Lisbon metropolitan area

Urban systems are the locus of consumption and engines of economic growth in a globalized world. Major cities offer then the most striking examples of the environmental and energy problems that accompany intense urbanization: as cities grow the flow of energy and materials increase and pose serious problems to global sustainability. It is therefore critical to understand the interactions between the socio-economic urban development and environmental pressures, and to develop models that may explain these interactions. Early efforts led to conceptual models of cities as urban ecosystems. Ecologists have described the city as a heterotrophic ecosystem highly dependent on large inputs of energy and materials and a vast capacity to absorb emissions and waste [1,3]. Wolman was the first to apply an urban metabolism approach to quantify the flows of energy and materials into and out of a hypothetical American city with a population of one million. Systems ecologists provided formal equations to describe the energy balance and the cycling of materials . Although these efforts have never been translated into operational simulation models, they have laid out the basis for urban-ecological research. A critical challenge in this context is how to balance service levels, asset management (at times with a growing maintenance backlog), and resource efficiency with respect to materials, energy and cost. In this paper the outline of a spatially resolved model of urban systems is described.Peer Reviewe