940 resultados para Weigh-in-Motion


Relevância:

90.00% 90.00%

Publicador:

Resumo:

"Contract no. 289-99-0004"--P. [2] of cover.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Several mechanisms for self-enhancing feedback instabilities in marine ecosystems are identified and briefly elaborated. It appears that adverse phases of operation may be abruptly triggered by explosive breakouts in abundance of one or more previously suppressed populations. Moreover, an evident capacity of marine organisms to accomplish extensive geographic habitat expansions may expand and perpetuate a breakout event. This set of conceptual elements provides a framework for interpretation of a sequence of events that has occurred in the Northern Benguela Current Large Marine Ecosystem (off south-western Africa). This history can illustrate how multiple feedback loops might interact with one another in unanticipated and quite malignant ways, leading not only to collapse of customary resource stocks but also to degradation of the ecosystem to such an extent that disruption of customary goods and services may go beyond fisheries alone to adversely affect other major global ecosystem concerns (e.g. proliferations of jellyfish and other slimy, stingy, toxic and/or noxious organisms, perhaps even climate change itself, etc.). The wisdom of management interventions designed to interrupt an adverse mode of feedback operation is pondered. Research pathways are proposed that may lead to improved insights needed: (i) to avoid potential 'triggers' that might set adverse phases of feedback loop operation into motion; and (ii) to diagnose and properly evaluate plausible actions to reverse adverse phases of feedback operation that might already have been set in motion. These pathways include the drawing of inferences from available 'quasi-experiments' produced either by short-term climatic variation or inadvertently in the course of biased exploitation practices, and inter-regional applications of the comparative method of science.

Relevância:

90.00% 90.00%

Publicador:

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Blurred edges appear sharper in motion than when they are stationary. We proposed a model of this motion sharpening that invokes a local, nonlinear contrast transducer function (Hammett et al, 1998 Vision Research 38 2099-2108). Response saturation in the transducer compresses or 'clips' the input spatial waveform, rendering the edges as sharper. To explain the increasing distortion of drifting edges at higher speeds, the degree of nonlinearity must increase with speed or temporal frequency. A dynamic contrast gain control before the transducer can account for both the speed dependence and approximate contrast invariance of motion sharpening (Hammett et al, 2003 Vision Research, in press). We show here that this model also predicts perceived sharpening of briefly flashed and flickering edges, and we show that the model can account fairly well for experimental data from all three modes of presentation (motion, flash, and flicker). At moderate durations and lower temporal frequencies the gain control attenuates the input signal, thus protecting it from later compression by the transducer. The gain control is somewhat sluggish, and so it suffers both a slow onset, and loss of power at high temporal frequencies. Consequently, brief presentations and high temporal frequencies of drift and flicker are less protected from distortion, and show greater perceptual sharpening.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Blurred edges appear sharper in motion than when they are stationary. We (Vision Research 38 (1998) 2108) have previously shown how such distortions in perceived edge blur may be accounted for by a model which assumes that luminance contrast is encoded by a local contrast transducer whose response becomes progressively more compressive as speed increases. If the form of the transducer is fixed (independent of contrast) for a given speed, then a strong prediction of the model is that motion sharpening should increase with increasing contrast. We measured the sharpening of periodic patterns over a large range of contrasts, blur widths and speeds. The results indicate that whilst sharpening increases with speed it is practically invariant with contrast. The contrast invariance of motion sharpening is not explained by an early, static compressive non-linearity alone. However, several alternative explanations are also inconsistent with these results. We show that if a dynamic contrast gain control precedes the static non-linear transducer then motion sharpening, its speed dependence, and its invariance with contrast, can be predicted with reasonable accuracy. © 2003 Elsevier Science Ltd. All rights reserved.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Blurred edges appear sharper in motion than when they are stationary. We have previously shown how such distortions in perceived edge blur may be explained by a model which assumes that luminance contrast is encoded by a local contrast transducer whose response becomes progressively more compressive as speed increases. To test this model further, we measured the sharpening of drifting, periodic patterns over a large range of contrasts, blur widths, and speeds Human Vision. The results indicate that, while sharpening increased with speed, it was practically invariant with contrast. This contrast invariance cannot be explained by a fixed compressive nonlinearity since that predicts almost no sharpening at low contrasts.We show by computational modelling of spatiotemporal responses that, if a dynamic contrast gain control precedes the static nonlinear transducer, then motion sharpening, its speed dependence, and its invariance with contrast can be predicted with reasonable accuracy.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Lecture on the topic of the representation of violence in motion pictures, presented at Books & Books Coral Gables on January 29, 2013.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This practice-led research looks at the ways in which the colonial archive, and the colonial photographic archive in particular, can be reconstructed to produce new critical histories. The research argues for the potential of the moving image as a tool for re-staging colonial archives, as a means of generating responsible ways of looking at, and of engaging with our troubled collective pasts. In my practice I mix the photographic archive of the Anglo-Iranian Oil Company(which became BP) with my family’s photographs from Iran, and with the documentation and narrativization of my encounter with both of these sets of materials, within the moving image. Through this process I address questions about the nature of the photographic archive and the search for historical meaning within it; the question of the researcher’s position within the archive and within the history she produces; and I investigate the affective power of colonial photographs within film and the experience of untimeliness which they produce. While addressing problems associated with the failure of photographic archives to offer access to any stable, transparent meaning, I show how engaging with slippages of meaning can produce other kinds of historical knowledge. But I also argue that attending to the impression of the ‘real’ produced by the colonial photograph as it appears within film, makes the past felt in the present tense, in ways that draw attention to the responsibility of being an onlooker in a situation of injustice. In addition I show how registering the place and time of the researcher within the new filmic archive in motion produces an effective means of imaginative time travel and a lively experience of history.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

International migration sets in motion a range of significant transnational processes that connect countries and people. How migration interacts with development and how policies might promote and enhance such interactions have, since the turn of the millennium, gained attention on the international agenda. The recognition that transnational practices connect migrants and their families across sending and receiving societies forms part of this debate. The ways in which policy debate employs and understands transnational family ties nevertheless remain underexplored. This article sets out to discern the understandings of the family in two (often intermingled) debates concerned with transnational interactions: The largely state and policydriven discourse on the potential benefits of migration on economic development, and the largely academic transnational family literature focusing on issues of care and the micro-politics of gender and generation. Emphasizing the relation between diverse migration-development dynamics and specific family positions, we ask whether an analytical point of departure in respective transnational motherhood, fatherhood or childhood is linked to emphasizing certain outcomes. We conclude by sketching important strands of inclusions and exclusions of family matters in policy discourse and suggest ways to better integrate a transnational family perspective in global migration-development policy.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This chapter examines how the choreography of affect in two dance theatre works creates a space of affective adjacency—a space in which the building of an alternative structure of feeling and an alternative economy of the body can be experienced. Focusing on the choreographic use of repetition in Junk Ensemble’s Bird With Boy (2011) and Fabulous Beast Dance Theatre’s Rian (2011), it shows how the work required to build an alternative affective space can become visible. Although affect is most often viewed as a preconscious, ephemeral phenomenon (a passage of intensities), that can have little or no lasting impact on socio-political action, theorists such as Megan Watkins have argued for a consideration of the ‘cumulative aspects of affect’. Highlighting Spinoza’s distinction between affectus (the capacity for a body to affect and be affected), and affectio (the impact the affecting body leaves on the affected), Watkins points out that affectio can ‘leave a residue’ allowing for the ‘capacity of affect to be retained, to accumulate, to form dispositions and thus shape subjectivities’. The choreography of repetition in Bird With Boy and Rian presents sites for an examination of this accumulation of affect and its capacity not only to form and shape dispositions, but also, as Lauren Berlant suggests, ‘to move along and make worlds, situations, and environments’.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Thesis (Ph.D.)--University of Washington, 2016-07

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The voltage profile of the catenary between traction substations (TSSs) is affected by the trolleybus current intake and by its position with respect to the TSSs: the higher the current requested by the bus and the further the bus from the TSSs, the deeper the voltage drop. When the voltage drops below 500V, the trolleybus is forced to decrease its consumption by reducing its input current. This thesis deals with the analysis of the improvements that the installation of an BESS produces in the operation of a particularly loaded FS of the DC trolleybus network of the city of Bologna. The stationary BESS is charged by the TSSs during off-peak times and delivers the stored energy when the catenary is overloaded alleviating the load on the TSSs and reducing the voltage drops. Only IMC buses are considered in the prospect of a future disposal of all internal combustion engine vehicles. These trolleybuses cause deeper voltage drops because they absorb enough current to power their traction motor and recharge the on board battery. The control of the BESS aims to keep the catenary voltage within the admissible voltage range and makes sure that all physical limitations are met. A model of FS Marconi Trento Trieste is implemented in Simulink environment to simulate its daily operation and compare the behavior of the trolleybus network with and without BESS. From the simulation without BESS, the best location of the energy storage system is deduced, and the battery control is tuned. Furthermore, from the knowledge of the load curve and the battery control trans-characteristic, it is formulated a prediction of the voltage distribution at BESS connection point. The prediction is then compared with the simulation results to validate the Simulink model. The BESS allows to decrease the voltage drops along the catenary, the Joule losses and the current delivered by the TSSs, indicating that the BESS can be a solution to improve the operation of the trolleybus network.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The thesis explores recent technology developments in the field of structural health monitoring and its application to railway bridge projects. It focuses on two main topics. First, service loads and effect of environmental actions are modelled. In particular, the train moving load and its interaction with rail track is considered with different degrees of detail. Hence, results are compared with real-time experimental measurements. Secondly, the work concerns the identification, definition and modelling process of damages for a prestressed concrete railway bridge, and their implementation inside FEM models. Along with a critical interpretation of the in-field measurements, this approach results in the development of undamaged and damaged databases for the AI-aided detection of anomalies and the definition of threshold levels to prompt automatic alert interventions. In conclusion, an innovative solution for the development of the railway weight-in-motion system is proposed.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Klopfer's differentiation of movement scores, among which inanimate movement integrating the minor movements group, was no doubt opportune and needed. Their peculiar meaning has been clearly stressed and enriched by Piotrowski in his reformulation of Rorschach variables. It is our belief that Rorschach himself would take such step. Our criteria for scoring this determinant are somewhat different of both Klopfer's and Piotrowski's. On the one hand, masks, facial traits, emotional expressions, body parts in motion are not entered there. On the other, we score as such human or animal movement, provided this does not originate in the blot shape directly, but in the subjective reaction against the sensed muscular tension. Basic requirement for this scoring is the kinesthetic component, as for Mever since Rorschach's elaboration; and common trait distinctive for any response to be so scored ? be it an abstraction, an inanimate object, an animal or human being ? must be the subjective way of feeling the movement: (a) intention, blocking, struggle for achieving, for instance, or (b) activity of nature elements. Due to this subjective meaning we use the symbol m'intead of mfor this category. We already find these two kinds (a) and (b) of movement responses in Rorschach's text, respectively in the Examplesand in his posthumous Contribution.Either may point to a flight from emotional stress or to outstanding mental ability.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Universidade Estadual de Campinas . Faculdade de Educação Física