People travel in the real world and leave their location history in a form of trajectories. These trajectories do not only connect locations in the physical world but also bridge the gap between people and locations. This paper introduces a social networking service, called GeoLife, which aims to understand trajectories, locations and users, and mine the correlation between users and locations ...

The widespread use of mobile devices allows gathering large amounts of moving objects’ trajectories. However, just trajectories are often not enough to enable movements understanding. On the other hand, users’ posts in social media can be regarded as sparse and freely annotated movement traces, which can also be collected via mobile devices. This paper proposes a method for automatically fusing...

BACKGROUND Few studies have examined the trajectories of symptom severity in first episode psychosis (FEP) and their impact on functioning. This study aimed to identify discrete trajectories of positive, negative and general psychopathological symptoms and functioning, determine predictors of the identified symptom trajectories and subsequently investigate the relationship between symptom and f...

Movement data, that is, trajectories of mobile objects, are automatically collected in huge quantities by technologies such as GPS, GSM or RFID, among others. Publishing and exploiting such data is essential to improve transportation, to understand the dynamics of the economy in a region, etc. However, there are obvious threats to the privacy of individuals if their trajectories are published i...

OBJECTIVES Changes in employment contracts may impact the quality of working life, job insecurity, health and work-related attitudes. We examined the validity of two partly competing theoretical approaches. Based upon a segmentation approach, we expected no change in scores among stable trajectories, whereas upward trajectories were expected to be for the better and downward trajectories to be ...

We assume a differential drive mobile robot: two unsteered coaxial wheels are independently actuated. Each wheel has bounded velocity, but no bound on torque or acceleration. Pontryagin’s Maximum Principle gives an elegant description of the extremal trajectories, which are a superset of the time optimal trajectories. Further analysis gives an enumeration of the time optimal trajectories, and m...

Statistical classification of actions in videos is mostly performed by extracting relevant features, particularly covariance features, from image frames and studying time series associated with temporal evolutions of these features. A natural mathematical representation of activity videos is in form of parameterized trajectories on the covariance manifold, i.e. the set of symmetric, positive-de...

Background Quality of life (QOL) has become an increasingly recognized component of recovery for women with substance use disorders (SUDs) [1-3]. However, little is known about different trajectories of QOL among women with SUD over time. This study: a) identified heterogeneous QOL trajectories; b) examined predictors related to QOL trajectories; and c) investigated the association between QOL ...

We present a new generalized string model for Regge trajectories J = J(E2), where J and E are the orbital momentum and energy of the string, respectively. We demonstrate that this model is not to produce linear Regge trajectories, in contrast to the standard Nambu-Goto string, but generally nonlinear trajectories, which in many cases can be given in analytic form. As an example, we show how the...