Search results for "Geodesy"
showing 10 items of 116 documents
Forward acceleration of the centre of mass during ski skating calculated from force and motion capture data
2016
The purpose of this paper was to present and evaluate a methodology to determine the contribution of bilateral leg and pole thrusts to forward acceleration of the centre of mass (COM) of cross-country skiers from multi-dimensional ground reaction forces and motion capture data. Nine highly skilled cross-country (XC) skiers performed leg skating and V2-alternate skating (V2A) under constant environmental conditions on snow, while ground reaction forces measured from ski bindings and poles and 3D motion with high-speed cameras were captured. COM acceleration determined from 3D motion analyses served as a reference and was compared to the results of the proposed methodology. The obtained value…
The decline and displacement of custom in early modern Spain
2019
Summary This article aims to describe the reasons for the decline of customary law in the early modern era. Confining the discussion to a limited geographical setting – the Iberian Peninsula – the arguments I used might be easily applied to other European jurisdictions. Part I presents an explanation of the predominance of custom in the medieval Spanish legal traditions. Part II describes the general features of the law in the early modern era, since they contributed – to a greater or lesser degree – to the demise of custom. Part III focuses more specifically on the theoretical and practical reasons for the decline and displacement of custom in early modern Spain. Part IV describes the cons…
El método mejorado del tocón (ISUM) permite evaluar procesos de erosión del suelo en plantas injertadas utilizando medidas topográficas in situ
2021
[EN] Policymakers, stakeholders and rural inhabitants must be aware of the relevance of soil erosion as an irreversible landdegradation process. This is key to achieve the land degradation neutrality challenge and the sustainability of humankindand natural ecosystems. Agricultural areas are being affected by soil erosion threatening soil quality and, subsequently,food security. Therefore, it is necessary to develop new techniques and methods visually friendly and easy to be accessedto survey and assess the soil erosion concerns. ISUM (Improve Stock Unearthing Method) is a well-contrasted procedureto estimate and map soil mobilisation and erosion rates. To achieve this goal, using the plant …
Locating Objects Away from Earth Surface: Positioning Accuracy
2013
The motion of the Galileo and GPS satellite constellations is simulated in Schwarzschild space-time, whereas photons travel in Minkowski space-time. This is a good enough approach to deal with the main goal of this paper: the study of positioning accuracy in the framework of the so-called relativistic positioning. Our study is based on numerical 4D simulations. In this meeting, the contribution of J.A. Morales-Lladosa contains some basic ideas which have been important to perform our numerical calculations. For four chosen emitters (satellites) of a certain constellation, many receivers located at different distances from Earth surface and in distinct directions are considered. Thus, we ver…
Method to find the Minimum 1D Linear Gradient Model for Seismic Tomography
2016
The changes in the state of a geophysical medium before a strong earthquake can be found by studying of 3D seismic velocity images constructed for consecutive time windows. A preliminary step is to see changes with time in a minimum 1D model. In this paper we develop a method that finds the parameters of the minimum linear gradient model by applying a two-dimensional Taylor series of the observed data for the seismic ray and by performing least-square minimization for all seismic rays. This allows us to obtain the mean value of the discrete observed variable, close to zero value.
Performance of the First ANTARES Detector Line
2009
In this paper we report on the data recorded with the first Antares detector line. The line was deployed on the 14th of February 2006 and was connected to the readout two weeks later. Environmental data for one and a half years of running are shown. Measurements of atmospheric muons from data taken from selected runs during the first six months of operation are presented. Performance figures in terms of time residuals and angular resolution are given. Finally the angular distribution of atmospheric muons is presented and from this the depth profile of the muon intensity is derived.
Vertical jumping height and horizontal overhead throwing velocity in young male athletes
1992
The purpose of this study was to examine the effects of calendar and skeletal age, anthropometric dimensions, training history and their interactions on vertical jumping height and horizontal overhead throwing velocity in a cross-section of 318 young male athletes (age range 9-16 years) participating in cross-country skiing (n = 70), basketball (n = 40), apparatus gymnastics (n = 19), ice hockey (n = 50), track and field (n = 89) and wrestling (n = 50). Vertical jumping height was measured with four different loads held on the shoulders and then interpolated for loads representing 0 and 40% body mass. Horizontal overhead throwing velocity using both hands was determined for seven balls of d…
Effect of skiing speed on ski and pole forces in cross-country skiing.
2008
Purpose: The present study characterized pole and ski forces in classical technique cross-country skiing. Eight elite junior cross-country skiers performed diagonal skiing at 65%, 75%, 90%, and 100% of maximum speed on a stable 100-m-low uphill (2.5[degrees]). Method: The ski and the pole forces (vertical (Fz) and horizontal (Fy) directions) on the right and left sides were recorded separately when the skier skied over a special custom-made force platform system placed at the end of the uphill course. The entire system consisted of four separate 20-m-long rows of 1-m-long force plates connected in series, row by row. Results: When the forces were averaged for the various functional phases o…
Arm end-point trajectories under normal and micro-gravity environments.
2001
Abstract The purpose of the present experiment was to study the way in which the CNS represents gravitational force during vertical arm pointing movements. Movements in upward and downward directions were executed by two cosmonauts in normal-gravity and weightlessness. Analyses focused upon finger kinematics in the sagittal plane. In normal-gravity, downward direction movements showed smaller curvatures and greater relative times to peak velocity ( AT MT ) when compared with upward direction movements. Data from the weightlessness experiments showed that whilst downward movements decreased their curvature during space flight, curvatures of upward movements changed slightly. Furthermore, AT …
Does the centre of mass remain stable during complex human postural equilibrium tasks in weightlessness?
2001
In normal gravity conditions the execution of voluntary movement involves the displacement of body segments as well as the maintenance of a stable reference value for equilibrium control. It has been suggested that centre of mass (CM) projection within the supporting base (BS) is the stabilised reference for voluntary action, and is conserved in weightlessness. The purpose of this study was to determine if the CM is stabilised during whole body reaching movements executed in weightlessness. The reaching task was conducted by two cosmonauts aboard the Russian orbital station MIR, during the Franco-Russian mission ALTAIR, 1993. Movements of reflective markers were recorded using a videocamera…