Search results for "cluster-based method"
showing 3 items of 3 documents
Density-based Algorithm and Network Analysis for GPS Data
2019
La diffusione dei sistemi di localizzazione GPS offre numerose opportunita per la raccolta di dati di movimento. I dati GPS presentano diversi elementi di complessita derivanti anche dall’elevato dettaglio temporale e territoriale. Numerosi sono gli aspetti che possono essere presi in esame per tale tipologia di dati. Il presente studio propone un approccio statistico basato sull’identificazione dei punti di attrazione e sullo studio dei network. In particolare, viene proposto un algoritmo di identificazione di cluster, sulla base della densita di punti, che vengono sintetizzati in un network che riassume il comportamento individuale. In un secondo step, i movimenti complessivi sono aggrega…
Identification of points of attraction and network analysis for GPS tracking data
2019
Global positional system data provide accurate information on units’ movements from both the temporal and the spatial perspective. Several aspects of these movements can be analyzed according to the aim of interest. In this study, we focus on statistical methods for the identification of points of interest and for the analysis of the network of movements for GPS data. A density-based cluster algorithm is applied to summarize the vast amount of information and to find the most relevant points of attraction. A directed network synthesizes the individual unit’s path by using the latter information. Finally, we aggregate the units’ paths in a weighted directed network which is studied through n…
A pre-processing and network analysis of GPS tracking data
2020
Global Positioning System (GPS) devices afford the opportunity to collect accurate data on unit movements from temporal and spatial perspectives. With a special focus on GPS technology in travel surveys, this paper proposes: (1) two algorithms for the pre-processing of GPS data in order to deal with outlier identification and missing data imputation; (2) a clustering approach to recover the main points of interest from GPS trajectories; and (3) a weighted-directed network, which incorporates the most relevant characteristics of the GPS trajectories at an aggregate level. A simulation study shows the goodness-of-fit of the imputation data algorithm and the robustness of the clustering algori…