Understanding Extended Projected Profile (EPP) Trajectory Error Using a Medium-Fidelity Aircraft Simulation

A critical component of Trajectory-Based Operations is the ability for a consistent and accurate 4-dimensional trajectory to be shared and synchronized between airborne and ground systems as well as amongst various ground automation systems. The Aeronautical Telecommunication NetworkBaseline 2 standard defines the Extended Projected Profile (EPP) trajectory that can be sent via Automatic Dependent Surveillance-Contract from an aircraft to ground automation. The EPP trajectory message contains a representation of the reference trajectory from an aircrafts Flight Management System (FMS). In this work, a set of scenarios were run in a medium-fidelity aircraft and FMS simulation to perform an initial characterization of EPP trajectory errors under a given set of conditions. The parameters investigated were the route length, route type, wind magnitude error, wind direction error, and with and without a required time-of-arrival constraint

Connectivity-Enforcing Hough Transform for the Robust Extraction of Line Segments

Global voting schemes based on the Hough transform (HT) have been widely used to robustly detect lines in images. However, since the votes do not take line connectivity into account, these methods do not deal well with cluttered images. In opposition, the so-called local methods enforce connectivity but lack robustness to deal with challenging situations that occur in many realistic scenarios, e.g., when line segments cross or when long segments are corrupted. In this paper, we address the critical limitations of the HT as a line segment extractor by incorporating connectivity in the voting process. This is done by only accounting for the contributions of edge points lying in increasingly larger neighborhoods and whose position and directional content agree with potential line segments. As a result, our method, which we call STRAIGHT (Segment exTRAction by connectivity-enforcInG HT), extracts the longest connected segments in each location of the image, thus also integrating into the HT voting process the usually separate step of individual segment extraction. The usage of the Hough space mapping and a corresponding hierarchical implementation make our approach computationally feasible. We present experiments that illustrate, with synthetic and real images, how STRAIGHT succeeds in extracting complete segments in several situations where current methods fail.Comment: Submitted for publicatio

Social networks and digital influencers: their role In customer decision journey in tourism

Several studies have shown the impact of social media on tourism and the role of digital influencers. However, the relationship between social media, digital influencers, and the customer decision journey has not been much studied. To help fill this gap, the present study examines the role of digital influencers during each phase of the customer decision journey using an online survey. The findings from 244 social media users show that the majority use social networks when planning a trip, however, sharing the experiences of other travellers is not a relevant aspect. While, overall, digital influencers have no significant impact, their followers tend to value their content, visit the sites they suggest, and share their own experiences, mostly through Instagram.FCT-Foundation for Science and TechnologyPortuguese Foundation for Science and Technology [UID/SOC/04020/2019

Tentativas de Suicídio em Adolescentes Internados na Unidade de Internamento de Pedopsiquiatria do Centro Hospitalar de Lisboa Central.

Os Comportamentos Auto-Destrutivos (CAD) designam todos os comportamentos que põem em causa a integridade física de um indivíduo. Quando associados a uma intenção de morrer fala-se de Tentativa de Suicídio (TS), sendo esta o factor preditor mais importante de risco de suicídio, que nos EUA é a 3ª causa de morte entre os adolescentes. Na adolescência, as TS são mais frequentes no género feminino e os suicídios no masculino, concorrendo para tal uma série de factores biopsicossociais. O presente estudo retrospectivo observacional pretende, assim, caracterizar a população de adolescentes internados no Internamento de Pedopsiquiatria do CHCL por TS, entre Janeiro de 2006 e Fevereiro de 2009, através da recolha de dados demográficos, clínicos e psicopatológicos presentes nos processos clínicos

Central Algarve tufa platforms, Southern Portugal. Geomorphological characterization and genesis.

Modern and fossil carbonate tufa outcrops exist in the Algarve (S Portugal), where climate is Mediterranean and all modern incrusting springs are intermittent and fed by Jurassic aquifers. The major Pleistocene tufa on the Algibre flexure southern slopes are in the Cadouço, São Lourenço and Rio Seco streams basins. There were identified fluvial barrier tufas and low energy fluvial tufas. The Algarve has three main geomorphological domains: the Paleozoic flysch mountains, the Meso-cenozoic karst hills and the littoral Plio-Pleistocene detrital platform.Located in the Eurasian-Nubian plates boundary, the whole system have been deformed by distensive and compressive tectonics, which give rise to a complex groundwater system. Neotectonical activity has been reported in many works. Feio (1952) identified Pliocene and Quaternary marine platforms up to 160 m a.s.l., but also mature levels at 200 m along with other plain surfaces. The largest tufa platforms lie in unconformity with the currentdrainage system, where outcrops are dominated by low gradient facies, v. g. detrital bedded lime muds. Machados platform is dominated by bryophytes and other rapid flow facies, and cemented riverbed upstream. These outcrops lie down on larger areas in Loulé and Lagos e Relva, at altitudes between 160-200 and 120-150 respectively. Environmentally conformal tufas occupy some sectors of the modern Cadouço, Rio Seco and São Lourenço streams. Modern tufa range from spring dominated mounds in Lagos eRelva and barrier and low gradient fluvial dominated tufas (v. g. São Lourenço and Loulé). The ocean proximity enables the formation of eustatic platforms, which provided substratum for tufa accumulations. Vertical movements, including salt tectonics, and lowstands promoted fluvial incision and later tufa developments in modern streams. Acknowledgments: Financed by the Fundação para a Ciência e Tecnologia PhD grant SFRH/BD/62323/2009