• openAccess   A Comprehensive and Reproducible Comparison of Clustering and Optimization Rules in Wi-Fi Fingerprinting2020 

      Torres-Sospedra, Joaquín; Richter, Philipp; Moreira, Adriano; Mendoza-Silva, Germán Martín; Lohan, Elena Simona; Trilles, Sergio; Matey-Sanz, Miguel; Huerta, Joaquin IEEE (2020-08-17)
      Wi-Fi fingerprinting is a well-known technique used for indoor positioning. It relies on a pattern recognition method that compares the captured operational fingerprint with a set of previously collected reference samples ...
    • openAccess   A New Under-Sampling Method to Face Class Overlap and Imbalance 

      Guzmán-Ponce, Angélica; Valdovinos Rosas, Rosa María; Sánchez Garreta, Josep Salvador; Marcial-Romero, J. Raymundo MDPI (2020-07-07)
      Class overlap and class imbalance are two data complexities that challenge the design of effective classifiers in Pattern Recognition and Data Mining as they may cause a significant loss in performance. Several solutions ...
    • openAccess   Characterising Players of a Cube Puzzle Game with a Two-level Bag of Words 

      Anadón, Xavier; Sanahuja, Pablo; Traver, V. Javier; Lopez, Angeles; Ribelles, Jose Association for Computing Machinery (ACM) (2021-06)
      This work explores an unsupervised approach for modelling players of a 2D cube puzzle game with the ultimate goal of customising the game for particular players based solely on their interaction data. To that end, user ...
    • openAccess   Improving DBSCAN for Indoor Positioning Using Wi-Fi Radio Maps in Wearable and IoT Devices 

      Quezada Gaibor, Darwin; Klus, Lucie; Torres-Sospedra, Joaquín; Lohan, Elena Simona; Nurmi, Jari; Huerta, Joaquin IEEE (2020-10-05)
      IoT devices and wearables may rely on Wi-Fi finger-printing to estimate the position indoors. The limited resources of these devices make it necessary to provide adequate methods to reduce the operational computational ...
    • openAccess   Lightweight Wi-Fi Fingerprinting with a Novel RSS Clustering Algorithm 

      Quezada Gaibor, Darwin; Torres-Sospedra, Joaquín; Nurmi, Jari; Koucheryavy, Yevgeni; Huerta, Joaquin IEEE (2021-11-29)
      Nowadays, several indoor positioning solutions sup-port Wi-Fi and use this technology to estimate the user position. It is characterized by its low cost, availability in indoor and outdoor environments, and a wide variety ...
    • openAccess   New Cluster Selection and Fine-grained Search for k-Means Clustering and Wi-Fi Fingerprinting 

      Torres-Sospedra, Joaquín; Quezada Gaibor, Darwin; Mendoza-Silva, Germán Martín; Nurmi, Jari; Koucheryavy, Yevgeni; Huerta, Joaquin IEEE (2020-06-02)
      Wi-Fi fingerprinting is a popular technique for Indoor Positioning Systems (IPSs) thanks to its low complexity and the ubiquity of WLAN infrastructures. However, this technique may present scalability issues when the ...
    • closedAccess   Point Patterns Occurring on Complex Structures in Space and Space-Time: An Alternative Network Approach 

      Eckardt, Matthias; Mateu, Jorge Taylor & Francis (2017-10)
      This article presents an alternative approach of analyzing possibly multitype point patterns in space and space–time that occur on network structures, and it introduces several different graph-related intensity measures. ...
    • openAccess   RSS Fingerprinting Dataset Size Reduction Using Feature-Wise Adaptive k-Means Clustering 

      Klus, Lucie; Quezada Gaibor, Darwin; Torres-Sospedra, Joaquín; Lohan, Elena Simona; Granell, Carlos; Nurmi, Jari IEEE (2020-10)
      Modern IoT devices, that include smartphones and wearables, usually have limited resources. They require efficient methods to optimize the use of internal storage, provide computational efficiency, and reduce energy ...
    • openAccess   Scalable and Efficient Clustering for Fingerprint-Based Positioning 

      Torres-Sospedra, Joaquín; Quezada Gaibor, Darwin; Nurmi, Jari; Koucheryavy, Yevgeni; Lohan, Elena Simona; Huerta, Joaquin IEEE (2023)
      Abstract: Indoor positioning based on IEEE 802.11 wireless LAN (Wi-Fi) fingerprinting needs a reference data set, also known as a radio map, in order to match the incoming fingerprint in the operational phase with the ...