43 documents found, page 1 of 5
Hyperparameterless k-NN for Wi-Fi fingerprinting
Torres-Sospedra, Joaquín; Silva, Ivo Miguel Menezes; Pendão, Cristiano Gonçalves; Meneses, Filipe; Moreira, AdrianoFingerprint-based solutions mostly rely on variants of the k -NN algorithm. Despite the core operation of the model being quite simple, several implementation details can be exploited to enhance positioning accuracy. Recent works have been focusing on dynamically setting the value of k as, depending on the location, the algorithm may require different levels of reference data to provide a good position estimate...
Older people living alone: a predictive model of fall risk
Lage, Isabel; Braga, Fátima; Almendra, Manuela; Meneses, Filipe; Teixeira, Laetitia; Araújo, OdeteFalls in older people are a result of a combination of multiple risk factors. There are few studies involving predictive models in a community context. The aim of this study was to determine the validation of a new model for predicting fall risk in older adults (65+) living alone in community dwellings (n = 186; n = 117) with a test–retest reliability study. We consider in the predictive model the significant f...
On the feasibility of using 5G enabled smartphones to improve safety of vulnera...
Puga, Joel; Meneses, Filipe; Moreira, AdrianoAutonomous vehicles require sophisticated sensors to safely and timely detect the conditions of the world around them and act accordingly. However, just like human senses, sensors have limitations and blind spots. Vulnerable Road Users, such as pedestrians and cyclists, are at particular risk since they can quickly come to the road from a blind spot too late for the vehicle to react. This article evaluates the ...
Let’s talk about k-NN for indoor positioning: Myths and facts in RF-based finge...
Torres-Sospedra, Joaquín; Pendão, Cristiano; Silva, Ivo; Meneses, Filipe; Quezada-Gaibor, Darwin; Montoliu, Raúl; Crivello, Antonino; Barsocchi, PaoloMicrosoft proposed RADAR in 2000, the first indoor positioning system based on Wi-Fi fingerprinting. Since then, the indoor research community has worked not only to improve the base estimator but also on finding an optimal RSS data representation. The long-term objective is to find a positioning system that minimises the mean positioning error. Despite the relevant advances in the last 23 years, a disruptive s...
Off-line evaluation of indoor positioning systems in different scenarios: the e...
Potorti, Francesco; Torres-Sospedra, Joaquín; Quezada-Gaibor, Darwin; Jimenez, Antonio Ramon; Seco, Fernando; Perez-Navarro, Antoni; Ortiz, MiguelEvery year, for ten years now, the IPIN competition has aimed at evaluating real-world indoor localisation systems by testing them in a realistic environment, with realistic movement, using the EvAAL framework. The competition provided a unique overview of the state-of-the-art of systems, technologies, and methods for indoor positioning and navigation purposes. Through fair comparison of the performance achieve...
A ubiquitous service-oriented automatic optical inspection platform for textile...
Gonzalez, Dibet Garcia; Castilla, Yusbel Chavez; Shaharadaby, Somayeh; Mackay, Ana Margarida; Soares, Lúcia; Guimarães, Pedro; Morais, FranciscoWithin a highly competitive market context, quality standards are vital for the textile industry, in which related procedures to assess respective manufacture still mainly rely on human-based visual inspection. Thereby, factors such as ergonomics, analytical subjectivity, tiredness and error susceptibility affect the employee's performance and comfort in particular and impact the economic healthiness of each co...
The IPIN 2019 indoor localisation competition-description and results
Potorti, Francesco; Park, Sangjoon; Crivello, Antonino; Palumbo, Filippo; Girolami, Michele; Barsocchi, Paolo; Lee, Soyeon; Torres-Sospedra, JoaquínIPIN 2019 Competition, sixth in a series of IPIN competitions, was held at the CNR Research Area of Pisa (IT), integrated into the program of the IPIN 2019 Conference. It included two on-site real-time Tracks and three off-site Tracks. The four Tracks presented in this paper were set in the same environment, made of two buildings close together for a total usable area of 1000 m2 outdoors and and 6000 m2 indoors...
In-house localization for Wi-Fi coverage diagnostics
Martins, Carlos Manuel; Moreira, Adriano; Ferreira, Ricardo; Meneses, FilipeTelecommunication operators and Internet Service Providers often face the problem of having residential customers complaining about deficient Wi-Fi coverage inside their houses and/or about the low quality of service while accessing the Internet. Addressing these complaints properly involves a comprehensive in-house diagnostic of the technical deployment, the use of specialized equipment and visits by qualified...
Radio maps for fingerprinting in indoor positioning
Meneses, Filipe; Moreira, Adriano; Costa, António; Nicolau, Maria JoãoIn spite of all the efforts done by researchers, today we still do not have a universal and ubiquitous solution for indoor positioning. Fingerprinting is one of the most well-known technologies used to build indoor positioning systems, using the radio signals to determine the user or device location, exploring the principle that each location has a different radio signature. Radio maps are mandatory to implemen...
Off-line evaluation of mobile-centric indoor positioning systems: the experienc...
Torres-Sospedra, Joaquín; Jiménez, Antonio R; Moreira, Adriano; Lungenstrass, Tomás; Lu, Wei-Chung; Knauth, Stefan; Mendoza-Silva, Germán MartínThe development of indoor positioning solutions using smartphones is a growing activity with an enormous potential for everyday life and professional applications. The research activities on this topic concentrate on the development of new positioning solutions that are tested in specific environments under their own evaluation metrics. To explore the real positioning quality of smartphone-based solutions and t...