Abstract

Abstract

Abstract
This study estimates alighting stops and transfers from entry-only Automatic Fare Collection (AFC) data. The methodology adopted includes two main steps: an implementation of the Trip Chaining Method (TCM) to estimate the alighting stops from AFC records and the subsequent application of criteria for the identification of transfers. For each pair of consecutive AFC records on the same smart card, a transfer is identified considering a threshold for the walking distance, a threshold for the time required to perform an activity, and the validation of different boarding routes. This methodology was applied to the case study of Porto, Portugal, considering all trips performed by a set of 19999 smart cards over one year. The results of this methodology allied with visualization techniques allowed to study Origin-Destination (OD) patterns by type of day, seasonally, and by user frequency, each analyzed at the stop level and at the geographic area level.

Abstract
In this paper, a solution to monitor the location of humans during their activity in the agriculture sector with the aim to boost productivity and efficiency is provided. Our solution is based on map-matching methods, that are used to track the path spanned by a worker along a specific activity in an agriculture culture. Two different cultures are taken into consideration in this study olives and vines. We leverage the symmetry of the geometry of these cultures into our solution and divide the problem three-fold initially, we estimate a path of a worker along the fields, then we apply the map-matching to such path and finally, a post-processing method is applied to ensure local continuity of the sequence obtained from map-matching. The proposed methods are experimentally evaluated using synthetic and real data in the region of Mirandela, Portugal. Evaluation metrics show that results for synthetic data are robust under several sampling periods, while for real-world data, results for the vine culture are on par with synthetic, and for the olive culture performance is reduced.

Abstract
Many Virtual Reality (VR) locomotion techniques have been proposed, but those explored for and with blind people are often custom-made or require specialized equipment. Consequently, it is unclear how popular techniques can support blind people's VR locomotion, blocking access to most VR experiences. We implemented three popular techniques - Arm Swinging, Linear Movement (joystick-based steering), and Point & Teleport - with minor adaptations for accessibility. We conducted a study with 14 blind participants consisting of navigation tasks with these techniques and a semi-structured interview. We found no differences in overall performance (e.g., completion time), but contrasting preferences. Findings highlight the challenges and advantages of each technique and participants' strategies. We discuss, among others, how augmenting the techniques enabled blind people to navigate in VR, the greater control of movement of Arm Swinging, the simplicity and familiarity of Linear Movement, and the potential for efficiency and for scanning the environment of Point & Teleport.

Abstract
Este artículo presenta un algoritmo para localización de fallas basado en un método de estimaciones de estado, válido para sistemas de distribución activos de media tensión. El algoritmo utiliza las mediciones registradas por unos pocos dispositivos de medición sincrofasoriales uPMUs, junto con pseudomediciones, para localizar con éxito la línea con falla. Primero se presenta la formulación de general de las estimaciones de estado bajo la suposición de que todas las barras son monitoreadas. Posteriormente, se define el método a seguir para conseguir detectar una falla con mínimo dos uPMUs. Finalmente, se desarrolla un algoritmo de localización óptima, cuyas restricciones se basan en mejorar los índices de confiabilidad del sistema. El método propuesto es validado en un sistema de distribución trifásico de 39 barras, donde el índice de confiabilidad de duración de interrupciones es reducido en un 22.01% con el despliegue de tan sólo dos uPMUs.