Search results for "special relativity"
showing 10 items of 60 documents
Does Bold Emphasis Facilitate the Process of Visual-Word Recognition?
2014
AbstractThe study of the effects of typographical factors on lexical access has been rather neglected in the literature on visual-word recognition. Indeed, current computational models of visual-word recognition employ an unrefined letter feature level in their coding schemes. In a letter recognition experiment, Pelli, Burns, Farell, and Moore-Page (2006), letters in Bookman boldface produced more efficiency (i.e., a higher ratio of thresholds of an ideal observer versus a human observer) than the letters in Bookman regular under visual noise. Here we examined whether the effect of bold emphasis can be generalized to a common visual-word recognition task (lexical decision: “is the item a wo…
Vectors, Tensors, Manifolds and Special Relativity
2015
Assuming that the reader is familiar with the notion of vectors, within a few pages, with a few examples, the reader will get to be familiar with the generic picture of tensors. With the specific notions given in this chapter, the reader will be able to understand more advanced tensor courses with no further effort. The transition between tensor algebra and tensor calculus is done naturally with a very familiar example. The notion of manifold and a few basic key aspects on Special Relativity are also presented.
Observer-Based ${H}_{\infty }$ Control Design for Nonlinear Networked Control Systems with Limited Information
2013
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2013/604249 Open Access This paper is concerned with the problem of designing a robust observer-based H∞ controller for discrete-time networked systems with limited information. An improved networked control system model is proposed and the effects of random packet dropout, time-varying delay, and quantization are considered simultaneously. Based on the obtained model, a stability criterion is developed by constructing an appropriate Lyapunov-Krasovskii functional and sufficient conditions for the existence of a dynamic quantized output feedback cont…
Evaluation of retro-reflective coating performance by reflectance and perceived relative brightness measurements
2011
Retro-reflective properties of six types and five different colors or retro-reflective materials were discussed in this paper. Reflectance optical indicatrix of samples was determined and compared to obtained psychophyisical data of perceived brightness of human observer. Microscopic structure of the retro-reflective active regions of RR's was studied. Statistically significant differences in reflectivity and brightness of various types and colors of RR's were found.
The Mona Lisa effect: Testing the limits of perceptual robustness vis-à-vis slanted images
2014
We report three experiments that test the limits of the Mona Lisa effect. The gaze of a portrait that is looking at us appears to follow us around as we move with respect to the picture. Even if our position is shifted considerably to the side, or if the picture is severely slanted, do we feel the gaze to be directed at us? We determined the threshold where this effect breaks down to be maximally 70? of picture slant relative to the observer. Different factors modulate this remarkable robustness, among them being the display medium and the nature of the picture. The threshold was considerably lower when the picture was mounted on a physical surface as opposed to a computer simulation of sla…
Exploring relationships between pianists’ body movements, their expressive intentions, and structural elements of the music
2011
Body movements during music performance have been found to be indicative of the performer’s musical intentionality, and contribute to an observer’s perception of expressive playing. This study investigates the effect of structural elements of the score, and the playing of different levels of expression on body movements during a piano performance. Pianists were required to play the same piece in four different performance conditions. Their movements were tracked by an optical motion capture system, and the comparisons that were made between specific parts of the body used, performance condition, and musical score locations were subsequently statistically examined. We found that the head an…
Classical electromagnetic radiation in noninertial reference frames
1991
Customarily electromagnetic radiation is defined with reference to some inertial laboratory frame. But such a definition is too narrow to be applicable to questions concerning accelerated observers,e.g. why an accelerated observer does not receive radiation from a co-accelerating charge. It is shown in this paper that a radiation concept introduced for inertial observers by Rohrlich and Teitelboim allows an extension to noninertial (accelerating and rotating) reference frames in a natural way. The generalized concept is explicitly dependent on the proper acceleration and the rotation of the observer’s laboratory frame. The case of radiation due to an accelerated point charge is treated in f…
Integral display for non-static observers
2017
We propose to combine the Kinect and the Integral-Imaging technologies for the implementation of Integral Display. The Kinect device permits the determination, in real time, of (x,y,z) position of the observer relative to the monitor. Due to the active condition of its IR technology, the Kinect provides the observer position even in dark environments. On the other hand, SPOC 2.0 algorithm permits to calculate microimages adapted to the observer 3D position. The smart combination of these two concepts permits the implementation, for the first time we believe, of an Integral Display that provides the observer with color 3D images of real scenes that are viewed with full parallax and which are…
The relativity experiment of MORE: Global full-cycle simulation and results
2015
BepiColombo is a joint ESA/JAXA mission to Mercury with challenging objectives regarding geophysics, geodesy and fundamental physics. In particular, the Mercury Orbiter Radio science Experiment (MORE) intends, as one of its goals, to perform a test of General Relativity. This can be done by measuring and constraining the parametrized post-Newtonian (PPN) parameters to an accuracy significantly better than current one. In this work we perform a global numerical full-cycle simulation of the BepiColombo Radio Science Experiments (RSE) in a realistic scenario, focussing on the relativity experiment, solving simultaneously for all the parameters of interest for RSE in a global least squares fit …
T-pattern detection and analysis for the discovery of hidden features of behaviour
2018
Abstract Background The behaviour of all living beings consists of hidden patterns in time; consequently, its nature and its underlying dynamics are intrinsically difficult to be perceived and detected by the unaided observer. Method Such a scientific challenge calls for improved means of detection, data handling and analysis. By using a powerful and versatile technique known as T-pattern detection and analysis (TPA) it is possible to unveil hidden relationships among the behavioural events in time. Results TPA is demonstrated to be a solid and versatile tool to study the deep structure of behaviour in different experimental contexts, both in human and non human subjects. Conclusion This re…