89,485 research outputs found
Human-data interaction in healthcare
No full textIn this chapter, we focus on an emerging strand of IT-oriented research, namely Human-Data Interaction (HDI) and on how this can be applied to healthcare. HDI regards both how humans create and use data by means of interactive systems, which can both assist and constrain them and the operational level of data work, which is both work on data and by data. Healthcare is a challenging arena where to test the potential of HDI towards a new, user-centered perspective on how to support and assess “data work”. This is especially true in current times where data are becoming increasingly big and many tools are available for the lay people, including doctors and nurses, to interact with health-related data. This chapter is a contribution in the direction of considering health-related data through the lens of HDI, and of framing data visualization tools in this strand of research. The intended aim is to let the subtler peculiarities among different kind of data and of their use emerge and be addressed adequately. Our point is that doing so can promote the design of more usable tools that can support data work from a user-centered and data quality perspective and the evidence-based validation of these tools
Following Mediterranean steps, the shortest way to reach nutritional goals. Evidence from computer personalized diets
No full textCo-auteurs: Maillot, M., Issa, C., Vieux, F., Lairon, D., Darmon, N.\
Designing Solutions for the Commons
No full textThe regeneration of the commons occurs through direct involvement of groups of people who interact closely with spaces, and who aim to improve the overall quality of life and experiences connected with those spaces. This process starts from an increased consciousness towards places that do not belong to the private realm but are public or can potentially be used by the society Revealing the commons means being aware of the potentialities of these “hidden places” to not only connect people with them, but for people to also create a previously unknown sense of community and ownership among themselves. By showing best practices developed by the Polimi DESIS Lab in the city of Milan and its surroundings, this paper reveals: how design relates to this process; the relationship between the time of involvement and the effectiveness of the results the short- and long-term impacts of these interventions; and the legacy of the regeneration, including both failures and successes
Afrocentricidade, agência e apropriação cultural a partir da análise de redes sociais
No full textMULUMBA, Issa. Afrocentricidade, agência e apropriação cultural a partir da análise de redes sociais. 2018. 18 f. Trabalho de Conclusão de Curso (Bacharelado em Humanidades) - Instituto de Humanidades e Letras, Universidade da Integração Internacional da Lusofonia Afro-Brasileira, São Francisco do Conde, 2018
Control of transient power during unintentional islanding of microgrids
No full textIn inverter-based microgrids, the paralleled inverters need to work in grid-connected mode and stand-alone mode and to transfer seamlessly between the two modes. In grid-connected mode, the inverters control the amount of power injected into the grid. In stand-alone mode, however, the inverters control the island voltage while the output power is dictated by the load. This can be achieved using the droop control. Inverters can have different power set-points during grid-connected mode but in stand-alone mode they all need their power set-points to be adjusted according to their power ratings. However, during sudden unintentional islanding (due to loss of mains), transient power can flow from inverters with high power setpoints to inverters with low power set-points, which can raise the DC link voltage of the inverters causing them to shut down. This paper investigates the transient circulating power between paralleled inverters during unintentional islanding and proposes a controller to limit it. The controller monitors the DC link voltage and adjusts the power set-point in proportion to the rise in the voltage. A small signal model of an islanded microgrid is developed and used to design the controller. Simulation and experimental results are presented to validate the design
Discovering gatherings based on individual mobility patterns: challenges and direction
No full textGiven a database of spatial trajectories reporting the movement of a set of objects in a time frame, the problem is to discover the groups of objects that stay in close proximity within a geographical area for a significant time. To deal with the problem, techniques for the discovery of collective patterns, e.g. the meeting pattern, have been proposed. Such techniques, however, impose stringent constraints on the object movement. In this paper we investigate a generalized, flexible approach that builds on the idea of expressing the collective pattern as sum of individual behaviors. We present a technique called k-Gathering for the discovery of gatherings of at least k objects, which leverages a recent method for the discovery of stop-and-move patterns. The experiments, conducted on both synthetic and real data, show that the direction is promising and that the approach can be effective also on low sampling rate trajectories
Analysis of power line communication networks using a new approach based on an efficient measurement technique
No full textIn this paper, we present an efficient measurement technique for the analysis of power line communication (PLC) signals. The frequency spectrum associated with PLC signals extends from 1 MHz to 30 MHz. The proposed technique can be applied to a network containing multiconductor overhead lines and/or underground cables and it complements the theoretical formalism based on scattering parameters presented previously in the work of F. Issa et al. (2002). The use of a vector network analyzer is recommended for the evaluation of the scattering parameters matrix. Based on the proposed approach, we present examples of simulations for the voltage level of the PLC signals for different simple configurations. The simulations are compared with experimental data and a satisfactory agreement is foundLRESCI-STI-F
Prediction of Breakdown Voltage of Long Air Gaps Under Switching Impulse Voltage Based on the ISSA-XGBoost Model
No full textIn transmission lines, the discharge characteristics of long air gaps significantly influence the design of external insulation. Existing machine learning models for predicting breakdown voltage are typically limited to single gaps and do not account for the combined effects of complex factors. To address this issue, this paper proposes a novel prediction model based on the Improved Sparrow Search Algorithm-optimized XGBoost (ISSA-XGBoost). Initially, a comprehensive dataset of 46-dimensional electric field eigenvalues was extracted for each gap using finite element simulation software and MATLAB. Subsequently, the model incorporated a comprehensive set of input variables, including electric field eigenvalues, gap distance, waveform and polarity of the switching impulse voltage, temperature, relative humidity, and atmospheric pressure. After training, the ISSA-XGBoost model achieved a Mean Absolute Percentage Error (MAPE) of 7.85%, a Root Mean Squared Error (RMSE) of 56.92, and a Coefficient of Determination (R2) of 0.9938, indicating high prediction accuracy. In addition, the ISSA-XGBoost model was compared with traditional machine learning models and other optimization algorithms. These comparisons further substantiated the efficacy and superiority of the ISSA-XGBoost model. Notably, the model demonstrated exceptional performance in terms of predictive accuracy under extreme atmospheric conditions
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Extracting stay regions with uncertain boundaries from GPS trajectories: a case study in animal ecology.
No full textIn this paper we present a time-aware, density-based clustering technique for the identi cation of stay regions in trajectories of low-sampling-rate GPS points, and its application to the study of animal migrations. A stay region is de ned as a portion of space which generally does not designate a precise geographical entity and where an object is signi cantly present for a period of time, in spite of relatively short periods of absence. Stay regions can delimit for example the
residence of animals, i.e. the home-range. The proposed technique enables the extraction of stay regions represented by dense and temporally disjoint sub-trajectories, through the speci cation of a small set of parameters related to density and presence. While this work takes inspiration from the eld of animal ecology, we argue that the approach can be of more general concern and used in perspective in different domains, e.g. the study of human mobility over large
temporal scales. We experiment with the approach on a case study, regarding the seasonal migration of a group of roe deer
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