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- A stochastic approach to optimize Maritime pine (Pinus pinaster Ait.) stand management scheduling under fire risk. An application in PortugalPublication . Ferreira, L.; Constantino, M.; Borges, J. G.The paper discusses research aiming at the development of a management scheduling model for even-aged stands that may take into consideration fuel treatments to address the risk of wildfires. A Stochastic dynamic programming (SDP) approach is proposed to determine the policy (e.g. the fuel treatment and thinning schedules and the rotation age) that produces the maximum expected discounted net revenue. Fuel treatment activities encompass shrub cleanings. Emphasis was on combining a deterministic stand-level growth and yield model with wildfire occurrence and damage models to design a SDP network. SDP stages are defined by age and state variables include both the stand basal area and the number of years since the last fuel treatment. Fire occurrence and damage scenarios are addressed at each stage. Results from an application to Maritime pine (Pinus pinaster Ait.) stand management scheduling in Leiria National Forest, Portugal, are presented. Results suggest that the modeling strategy may help assess the impact of wildfire risk on the optimal stand management schedule. They confirm that the maximum expected discounted net revenues decreases. Further, albeit some timber may be salvaged after the wildfire, rotation age also decreases when the risk of fire is considered. Finally, they provide interesting insights about the role of thinning and fuel treatment policies in mitigating risk.
- Patinhas Serviços de localização para animais desaparecidosPublication . Guerra, André; Tereso, Bruno; Brites, José; Silva, Catarina; Marcelino, LuisResumo — Todos os dias e por todo o lado existem animais que se perdem ou que são encontrados. Para grande parte destes casos existe uma dificuldade acrescida, não só em encontrar o dono do animal, mas também em reunir os esforços de inúmeros voluntários que, de uma forma ou outra, pretendem ajudar. De forma facilitar a procura de animais perdidos, foi proposto disponibilizar uma aplicação móvel em iOS, que permite a um utilizador colocar anúncios sobre animais perdidos e/ou encontrados, com base na localização onde foram vistos pela última vez. A aplicação serve igualmente de apoio à busca do animal. Sendo este um serviço que foca principalmente o senso comum e o espírito de entreajuda, torna-se importante notificar o utilizador no seu dia a dia, em situações em que ele pode ser verdadeiramente útil sem prejudicar, por exemplo, o seu itinerário. Por isso, foi criado um sistema de alertas que avisa o utilizador, ao passar numa determinada rua, quais os anúncios atuais na sua proximidade.
- State of the art of accessible development for smart devices: From a disable and not impaired point of viewPublication . Silva, João de Sousa e; Pereira, António; Gonçalves, Ramiro; Gomes, SílviaThe need and benefits of digital accessibility are evident and, with the current ubiquitous trends, the profits are hugely potentiated. However, the fast evolution is instigating some issues in this area's accessibility. To understand the conceivable impact of these issues' tenacity in society, general accessibility features are explained as a reasonable application for all parties. Nevertheless, the potential of ubiquitous computation in order to promote social integration of citizens with impairments is focused and elucidated. The benefits of applying so much effort on accessibility as well as on usability is asserted and related to universal design. Hence, in order to promote a more universal applications development, the mobile operating systems available in the market, which are more plausible to be chosen and used by people with impairments, are scrutinized and shown from a standpoint of a developer that has accessibility and usability concerns. The paper leads to the conclusions that ubiquitous computation may have power to nullify impairments but, to be assistive, several issues regarding the devices and the operating system that runs on them have to be taken in mind and considered.
- On finding representative non-dominated points for bi-objective integer network flow problemsPublication . Eusébio, A.; Figueira, J. R.; Ehrgott, M.This paper proposes a new algorithm to find a representation of the set of all non-dominated points of the bi-objective integer network flow problem. The algorithm solves a sequence of ε-constraint problems with a branch-and-bound algorithm to find a subset of non-dominated points that represents the set of all non-dominated points well in the sense of coverage or uniformity. At each iteration of the algorithm, one non-dominated point, determined by solving one ε-constraint problem, is added to the representation until it is guaranteed that the representation has the desired quality. Computational experiments on different problem types show the efficacy of the algorithm.
- Application of optimal experimental design concept to improve the estimation of model parameters in microbial thermal inactivation kineticsPublication . Gil, Maria M.; Miller, Fátima A.; Silva, Cristina L. M.; Brandão, Teresa R. S.The estimation of model parameters with high precision is of major importance in mathematical predictions. If a mathematical model is properly chosen and if the primary objective is to improve parameter estimation, underlying statistical theories can be applied. Precision increases with the number of experimental points. However, and in many situations, maximum precision is attained when sampling consists of replicates of specific experimental points. Experimental conditions can be optimized using the D-optimal design concept based on minimization of the generalized variance of the parameter estimates. The objective of this work was to use this methodology for the design of experiments for microbial inactivation processes described by a Gompertz-based model under isothermal and non-isothermal conditions. The application of D-optimal design concept considerably improved parameters precision, when compared to the commonly used heuristic designs.
- Internet of Things Aware WS-BPEL Business Processes - Context Variables and Expected ExceptionsPublication . Domingos, Dulce; Martins, Francisco; Cândido, Carlos; Martinho, RicardoBusiness processes can use Internet of Things (IoT) information to monitor context data in real-time and to respond to changes in their values in a timely fashion. For this matter, business process definition and execution languages should foresee an easy way for process modelers to define which values to monitor, and which automatic behaviors to adopt when these values change. In this paper, we propose the use of context variables to monitor sensor values, as well as a when-then language construct to detect and handle changes in these values within business processes.We define aWeb Services Business Process Execution Language (WS-BPEL) extension to convey these constructs, and implement then using a “BPEL language transformation” approach. With these contributions, process modelers can define IoT-aware business processes avoiding the increase of process complexity and keeping their focus on modeling the processes’ main logic. In addition, the language transformation approach assures the portability of processes using our constructs amongst WS-BPEL execution engines.
- Methodology to simulate the impact of a large deployment of a residential energy management system in the electricity gridPublication . Miguel, Pedro; Neves, Luís; Martins, A. GomesThe purpose of this work is to provide an insight for a possible methodology to implement demand response strategies at a city scale. The objective is to determine a range of values for the energy and power that can be made available through the large deployment of a residential energy management system. This work can help the distribution system operator to assess the impact of the usage of such technology at the grid level. The paper describes a methodology that identifies the start of operation cycles of appliances and other loads on a given general load diagram, enabling the simulation of load shifting caused by the operation of residential energy management systems. A simulation of an hypothetical 20% deployment of a residential energy management system on the city of Coimbra in Portugal, was performed. The results show the release of almost 3% of the demand on periods of higher price, but also the occurrence of a pronounced peak during the night period, an occurrence which may need to be dealt with, and for which some solutions are proposed.
- A Mobile Virtual Butler to Bridge the Gap between Users and Ambient Assisted Living: A Smart Home Case StudyPublication . Costa, Nuno; Domingues, Patrício; Fdez-Riverola, Florentino; Pereira, AntónioAmbient Intelligence promises to transform current spaces into electronic environments that are responsive, assistive and sensitive to human presence. Those electronic environments will be fully populated with dozens, hundreds or even thousands of connected devices that share information and thus become intelligent. That massive wave of electronic devices will also invade everyday objects, turning them into smart entities, keeping their native features and characteristics while seamlessly promoting them to a new class of thinking and reasoning everyday objects. Although there are strong expectations that most of the users’ needs can be fulfilled without their intervention, there are still situations where interaction is required. This paper presents work being done in the field of human-computer interaction, focusing on smart home environments, while being a part of a larger project called Aging Inside a Smart Home. This initiative arose as a way to deal with a large scourge of our country, where lots of elderly persons live alone in their homes, often with limited or no physical mobility. The project relies on the mobile agent computing paradigm in order to create a Virtual Butler that provides the interface between the elderly and the smart home infrastructure. The Virtual Butler is receptive to user questions, answering them according to the context and knowledge of the AISH. It is also capable of interacting with the user whenever it senses that something has gone wrong, notifying next of kin and/or medical services, etc. The Virtual Butler is aware of the user location and moves to the computing device which is closest to the user, in order to be always present. Its avatar can also run in handheld devices keeping its main functionality in order to track user when s/he goes out. According to the evaluation carried out, the Virtual Butler is assessed as a very interesting and loved digital friend, filling the gap between the user and the smart home. The evaluation also showed that the Virtual Butler concept can be easily ported to other types of possible smart and assistive environments like airports, hospitals, shopping malls, offices, etc.
- QEEG indexed frontal connectivity effects of transcranial pulsed current stimulation (tPCS): A sham-controlled mechanistic trialPublication . Saavedra, Laura Castillo; Morales-Quezada, Leon; Doruk, Deniz; Rozinsky, Joanna; Coutinho, Livia; Faria, Paula; Perissinotti, Iago; Wang, Qing-Mei; Fregni, FelipeTranscranial pulsed current stimulation (tPCS) is a non-invasive brain stimulation technique that employs weak, pulsed current at different frequency ranges, inducing electrical currents that reach cortical and subcortical structures. Very little is known about its effects on brain oscillations and functional connectivity and whether these effects are dependent on the frequency of stimulation. Our aim was to evaluate the effects of tPCS with different frequency ranges in cortical oscillations indexed by high-resolution qEEG changes for power and interhemispheric coherence. Thirty-eight healthy subjects were enrolled and received a single 20-min session of either sham or active stimulation with 1 Hz, 100 Hz or random frequency (1–5 Hz). We conducted an exploratory analysis to detect changes in mean power for theta, alpha and beta, and interhemispheric coherence for alpha and theta and four different sub-bands cognitive and non-specific adverse effects were recorded. We found that active stimulation with a random frequency ranging between 1 and 5 Hz is able to significantly increase functional connectivity for the theta and low-alpha band as compared to sham and active stimulation with either 1 or 100 Hz. Based on these findings, we discuss the possible effects of tPCS on resting functional connectivity for low-frequency bands in fronto-temporal areas. Future studies should be conducted to investigate the potential benefit of these induced changes in pathologic states.
- Human milk fat substitutes: Advances and constraints of enzyme‐catalyzed productionPublication . Ferreira-Dias, Suzana; Tecelão, CarlaThe production of triacylglycerols (TAGs) with similar structures to the human milk fat TAGs is only possible using sn-1,3 regioselective lipases as biocatalysts. The advances on the processes currently performed for the production of human milk fat substitutes (HMFS), namely the biocatalysts used, the best operation conditions, reactor types and operation modes, as well as the major drawbacks of these enzymatic systems, are addressed in this article.