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In this chapter, we explore the use of motion tracking methodology in developmental research. With motion tracking, also called motion capture, human movements can be precisely recorded and analyzed. Motion tracking provides developmental researchers with objective measurements of motor and (socio-)cognitive development. It can further be used to create carefully-controlled stimuli videos and can offer means of measuring development outside of the lab. We discuss three types of motion tracking that lend themselves to developmental applications. First, marker-based systems track optical or electromagnetic markers or sensors placed on the body and offer high accuracy measurements. Second, markerless methods entail image processing of videos to track the movement of bodies without participants being hindered by physical markers. Third, inertial motion tracking measures three-dimensional movements and can be used in a variety of settings. The chapter concludes by examining three example topics from developmental literature in which motion tracking applications have contributed to our understanding of human development.

Finite volumes of magma moving in confinement, store hydraulic potential energy for the generation, control and transmission of power. The Pascal’s principle in a hydraulic jack arrangement is used to model the vertical and lateral growth of sills. The small input piston of the hydraulic jack is equivalent to the feeder dike, the upper large expansible piston equivalent to the magmatic chamber and the inertial force of the magma in the dike is the input force. This arrangement is particularly relevant to the case of sills expanding with blunt tips, for which rapid fracture propagation is inhibited. Hydraulic models concur with experimental data that show that lateral expansion of magma into a sill is promoted when the vertical ascent of magma through a feeder dike reaches the bottom contact with an overlying, flat rigid-layer. At this point, the magma is forced to decelerate, triggering a pressure wave through the conduit caused by the continued ascent of magma further down (fluid-hammer effect). This pressure wave can provide overpressure enough to trigger the initial hydraulic lateral expansion of magma into an incipient sill, and still have enough input inertial force left to continue feeding the hydraulic system. The lateral expansion underneath the strong impeding layer, causes an area increase and thus, further hydraulic amplification of the input inertial force on the sides and roof of the incipient sill, triggering further expansion in a self-reinforcing process. Initially, the lateral pressure increase is larger than that in the roof allowing the sill to expand. However, expansion eventually increases the total integrated force on the roof allowing its uplift into either a laccolith, if the roof preserves continuity, or into a piston bounded by a circular set of fractures. Hydraulic models for shallow magmatic chambers, also suggest that laccolith-like intrusions require the existence of a self-supported chamber roof. In contrast, if the roof of magmatic chambers loses the self-supporting capacity, lopoliths and calderas should be expected for more or less dense magmas, respectively, owing to the growing influence of the density contrast between the host rock and the magma., Facultad de Ciencias Naturales y Museo, Centro de Investigaciones Geológicas

Bicycles are seen as a viable solution to a number of transportation problems: the use of bicycles alleviate congestion, reduce pollution and generally improve public health. In many congested cities, bicycles are the quickest means of transportation. The widespread use of bicycles, along with the exponential growth of electrically power assisted bicycles, could pose some safety issues related to reckless cycling. This paper presents an inertial measurement based approach to quantify and classify different riding styles. The bicycle velocity, longitudinal acceleration and angular rates are monitored to identify dangerous riding from three different perspective: longitudinal, vertical and lateral dynamics. In this way, it is possible to assign a number assessing the quality of each trip. The approach is developed using data collected from ad-hoc experiments and real-world data.

We use a single 2D laser scanner to 3D scan indoor environments, without any inertial measurement units or reference coordinates. The localization is done directly from the point cloud in an intrinsic manner compared to other state-of-the-art mobile laser scanning methods where external inertial or odometry sensors are employed and synchronized with the laser scanner. Our approach is based on treating the scanner as a holonomic system. A novel type of scanner platform, called VILMA, is designed and built to demonstrate the functionality of the presented approach. Results from flat-floor and non-flat-floor environments are presented. They suggest that intrinsic localization may be generalized for broader use.