Zoekresultaten

Semantic Segmentation of Terrestrial Laser Scans of Railway Catenary Arches

Peer-reviewed artikel over semantische segmentatie van point clouds.

Towards determination of power loss at a rowing blade

To analyze on-water rowing performance, a valid determination of the power loss due to the generation of propulsion is required. This power los can be calculated as the dot product of the net water force vector ( ~ F w;o ) and the time derivative of the position vector of the point at the blade where ~ F w;o is applied (~r PoA = w ). In this article we presented a method that allows for accurate determination of both parameters using a closed system of three rotational equations of motion for three different locations at the oar. Additionally, the output of the method has been validated. An oar was instrumented with three pairs of strain gauges measuring local strain. Force was applied at different locations of the blade, while the oar was fixed at the oarlock and the end of the handle. Using a force transducer and kinematic registration, the force vector at the blade and the deflection of the oar were measured. These data were considered to be accurate and used to calibrate the measured strain for bending moments, the deflection of the oar and the angle of the blade relative to its unloaded position. Additionally, those data were used to validate the output values of the presented method plus the associated instantaneous power output. Good correspondence was found between the estimated perpendicular blade force and its reference (ICC = .999), while the parallel blade force could not be obtained (ICC = .000). The position of the PoA relative to the blade could be accurately obtained when the perpendicular force was 5.3 N (ICC = .927). Instantaneous power output values associated with the perpendicular force could be obtained with reasonable accuracy (ICC = .747). These results suggest that the power loss due to the perpendicular water force component can be accurately obtained, while an additional method is required to obtain the power losses due to the parallel force.

The power to define resilience in socialhydrological systems

Since the early work on defining and analyzing resilience in domains such as engineering, ecology and psychology, the concept has gained significant traction in many fields of research and practice. It has also become a very powerful justification for various policy goals in the water sector, evident in terms like flood resilience, river resilience, and water resilience. At the same time, a substantial body of literature has developed that questions the resilience concept's systems ontology, natural science roots and alleged conservatism, and criticizes resilience thinking for not addressing power issues. In this study, we review these critiques with the aim to develop a framework for power-sensitive resilience analysis. We build on the three faces of power to conceptualize the power to define resilience. We structure our discussion of the relevant literature into five questions that need to be reflected upon when applying the resilience concept to social–hydrological systems. These questions address: (a) resilience of what, (b) resilience at what scale, (c) resilience to what, (d) resilience for what purpose, and (e) resilience for whom; and the implications of the political choices involved in defining these parameters for resilience building or analysis. Explicitly considering these questions enables making political choices explicit in order to support negotiation or contestation on how resilience is defined and used.

The list serves

Inspired by taxonomist Jack Goody’s theorizing of ‘ancient lists’ as ‘intellectual technologies’, this book analyzes listing practices in modern and contemporary formations of power, and how they operate in the installation and securing of the milieus of circulation that characterize Michel Foucault’s conception of governmentality. Propelling the list’s role in the delimitation and policing of risky and threatening elements from out of history and into a contemporary analysis of power, this work demonstrates how assemblages of computer, statistical, and list technologies first deployed by the Nazi regime continue to resonate significantly in the segmenting and constitution of a critical classification of contemporary homo sapiens: the terrorist class, or homo sacer.

The Recognition of Facial Expression an Experiment of Still Photos versus Three Dimensional Computer Graphic Images

Tourism as an exercise in three-dimensional power : evidence from Ghana

This study uses Lukes' (2005) three-dimensional power to explore the ability of traditional chiefs to influence slavery-based heritage tourism decisions. Traditional chiefs of five former slave communities in Ghana were in-depth interviewed about their efforts to harness community development through tourism and perceived influence in tourism decision-making process. Results indicated that despite being guardians of tourism resources, traditional chiefs perceive themselves to be powerless in affecting management decisions because of governmental control of local community institutions. They, however, exert considerable influence on tourism activities by either avoiding engagement or acting as community vanguards to discredit the interests of other stakeholders. Interview data support the theoretical tenets of Lukes' (2005) three-dimensional view of power, and the need to pursue cooperative tourism planning is discussed