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Svyatoslav Gromov
Svyatoslav Gromov

Inner Distortion Prototype Project V2 - DiSTORT...

So in 2017, the team built a prototype version of rift that had mechanical varifocal displays that could deliver proper depth of focus that used eye tracking to tell what you were looking at real time distortion correction to compensate for the magnification, moving the lenses on in the blur. So that way, only the things that you were looking at, were in focus just like the physical world, Zuckerberg said.

Inner Distortion Prototype Project V2 - DiSTORT...

After prolonged exposure to a distorted face with expanded or contracted inner features, a subsequently presented normal face appears distorted toward the opposite direction. This phenomenon, termed as face distortion aftereffect (FDAE), is thought to occur as a result of changes in the mechanisms involved in higher order visual processing. However, the extent to which FDAE is mediated by face-specific configural processing is less known. In the present study, we investigated whether similar aftereffects can be induced by stimuli lacking all the typical characteristics of a human face except for its first-order configural properties. We found a significant FDAE after adaptation to a stimulus consisting of three white dots arranged in a triangular fashion and placed in a gray oval. FDAEs occurred also when the adapting and test stimuli differed in size or when the contrast polarity of the adaptor image was changed. However, the inversion of the adapting image as well as the reduction of its contrast abolished the aftereffect entirely. Taken together, our results suggest that higher-level visual areas, which are involved in the processing of facial configurations, mediate the FDAE. Further, while adaptation seems to be largely invariant to contrast polarity, it appears sensitive to orientation and to lower level manipulations that affect the saliency of the inner features.

Advanced users can move objects as if they were telekinetic by controlling the gravity through space, which also can be used to enhance their own physical abilities, such as strength and speed. Users would also be capable of creating subspaces that can trap objects or be used as powerful projectiles. They can also use this ability to levitate in the air. At an ultimate level, users would be able to manipulate space in a very complex way such as (i.e. a room appearing bigger on the inside than it is on the outside, a never-ending corridor), phenomena, and other distortions that affect things at a universal level. They would also be able to manipulate other forms of esoteric space that has properties completely different from space in the real world, allowing them to achieve a plethora of effects, some even on nigh-omnipotent levels.

Inspired by the experience, Snoddy and fellow Nashville audio engineer Revis Hobbs developed and patented a prototype distortion effect box. They sold the design to the musical instrument company Gibson, who marketed it as the Maestro Fuzz-Tone guitar pedal. The Fuzz-Tone, however, failed to catch on until the pedal got into the hands of a Rolling Stone.

A design collaboration for developing and testing the T1MES phantom and its prototypes was established, consisting of clinicians, physicists, national metrology institutes (the US National Institute of Standards and Technology [NIST] and the German Physikalisch-Technische Bundesanstalt [PTB]) and a small-medium enterprise familiar with phantom production (Resonance Health [RH], Perth, Australia). Funding was secured including a grant from the European Association of Cardiovascular Imaging. Time and expertise was provided for free by the partnership. To engage a global community with constrained funding, the phantoms were gifted (first come, first served) to centers with the proviso that they: a) scan them fortnightly for 1 year and upload the results; b) engage with the partnership to explore any unexpected results; c) do not do anything that could potentially compromise (a) or (b) (e.g. deconstruct the phantom object); and d) give proper reference to the T1MES project if they use the phantoms for other purposes.

The 1-year study, now running, is expected also to give information about gel stability. It seems reasonable to expect sudden steps in T1 values from genuine changes in the acquisition, or scatter from any remaining uncontrolled parameters or imperfect temperature correction, but there would be a gradual monotonic drift as the gel water content changes. Agarose gel is inherently unstable even within a sealed tube, because the gel contracts as water leaves it, appearing as excess water (as droplets) in the gap left by the contraction, often visible on the inner wall of the tube. Note that this effect can occur within well-sealed tubes. It is unrelated to contamination because agarose without added nutrients does not support mould growth. Over time, this shrinkage may also occur in the matrix fill leading to air-gaps and B 0 distortion, potentially occurring near the tubes making a possible contribution to an apparent drift in T1 values over time. For the first time, the 1-year study will give large-scale initial data on the durability of this type of phantom. At study end, we aim to recall approximately 10 % of the phantoms which will be inspected for flaws in the gel using high-resolution 3D imaging, with collection also of long reference T1T2data as gel drying with shrinkage and condensation into the gap is known to occur even within a sealed tube. Centers are free to keep and use the T1MES phantoms after the 1-year study ends. There is no provision for return shipment to the coordinating site, nor any knowledge of how long the gels will remain usable.

  • In total five models, corresponding to three erosion control systems with two configurations, one nearshore detached submerged breakwater with four configurations, and one non-protected dune-beach system as reference, were studied. Model characteristics were derived from a prototype dune beach system from the NW coast of Portugal.The overall performance of each coastal protection scheme was evaluated against its hydraulic stability under wave loading and on its efficiency in maintaining a beach and in protecting the shoreline, based on the measurement of wave-induced morphodynamic changes over shorter and longer time-scales. As detailed bellow, five perspectives were considered in this assessment:Stability of geotextile encapsulated sand-systems under wave-loading;

  • Scour-depth development and scour-and-deposition patterns over the cross-shore length of the model; observations of erosion and backfilling during a test duration;

  • Dependency between scour-depth and the non-dimensional variables;

  • Storm response: changes in cross-shore beach-profile when exposed to storm conditions lasting for 30 minutes; beach levels drawdown at the structure and beach lowering;

  • Recovery between storms: response to the changing forcing conditions; build up during swell conditions, followed by beach levels drawdown during storm conditions; volumetric changes due to seasonal variability;

  • Coastal evolution: beach-profile change under persistent erosional conditions.

  • The geometric scale, NL, was selected as the largest model possible to obtain results of highest possible accuracy. For the 2D-experiments the selected model scale was based on considerations of the size of the prototype dune-beach system, the size of the available facility, grain size diameter of available sediments, and controlling factors with respect to the limiting values of the period and height of the model waves. The experiments were conducted only for irregular waves. The use of regular waves with height and period equal to those of significant wave can give inconsistent or erroneous results in the analysis of wave transformation and action of waves, Goda (2000[15]). The following procedures were taken forward while selecting the scaling criteria and scale ratios of the models employed:Geometrically undistorted model;

  • The nearshore hydrodynamics and sediment parameters were modelled according to Froude similarity;

  • The movable-bed model was composed of sand material;

  • The considered dominant mode of transport was suspended load transport;

  • The movable-bed model was built as large as possible so that the character of the wave breaking process is properly simulated, i.e., so that viscous and surface tension effects are negligible.

  • Three types of geosystems were used in the model tests; sand-filled containers, and sand wrapped around geotextile sheets made both from commercially available non-woven geotextile filters, and geotextile tubes of different sizes made from commercially available woven geotextile filters.Although the geosystems used in the model tests were made from commercially available geotextile materials, they are not obviously suitable for use in the prototype. Taken into account the information about the materials and scaling relationships, the following scaling aspects would require some consideration while scaling down the material properties: stiffness and tensile strength of the geotextile during wave experiments; stiffness and tensile strength of the geotextile during filling; and sand tightness.The proper scaling of several of the former aspects is not possible to fulfil, so a compromise is deemed necessary. Here it is assumed that geotextiles in the model are relatively too strong (about 1:1 to 1:3 of the prototype); yet, since they are not loaded to rupture it can be neglected. In regard to filling, the strength had only to ensure no damage to the geotextile during handling. Flexibility is warrant by a thinner geotextile. The hydraulic permeability of a GSC-structure depends mainly on the size between neighbouring containers (Recio, 2007[16]), thus so long the geometry is properly scaled the model represents adequately the permeability in the prototype. This means that aspects such as dimensions, placement and shape, also related to filling percentage and geotextile stiffness, have to be taken forward into the model. Both aspects, filling percentage and stiffness, may not be neglected in model, as failure to address them properly may result in a too large permeability in model compared to prototype by lower adaptation curvatures of the containers to the adjacent ones.The characteristics of sediment transport dynamics in the nearshore region were sought to be prevalent and thus, the dimensionless fall speed parameter was used to determine the length scale of the geometrically undistorted model, which was scaled to Froude similarity ([math]\lambda=1/12[/math]).In order to minimize scale effects produced by non-satisfied similarity, the model length scale was set to the maximum size that could be accommodated by the facilities at FEUP Laboratory of Hydraulics having in consideration the prototype characteristics, the sediment scale parameters, and controlling factors with respect to wave conditions. As the influence of surface tension is most significant for periods smaller than 0.35s, and for water-depths less than 2cm [1] it is anticipated that the scale effects due to non-satisfied Weber similarity are negligible. Moreover, the turbulent characteristics of the nearshore dynamics makes it safe to assume that the spurious effects of viscosity are not underestimated in the model. Sediment transport mechanisms along the cross-shore profile, namely the suspension by wave breaking and the sheet flow conditions in the swash zone, appear to be correctly reproduced in the model.In regard to the scaling down of the geotextile properties some simplifications were introduced. It was assumed that the geotextiles in the model were relatively too strong but since they were not loaded to rupture it is negligible. In regard to filling, the strength had only to ensure no damage to the geotextile during handling. Flexibility was warrant by a thinner geotextile. The hydraulic permeability of a GSC-structure depends mainly on the size between neighbouring containers (Recio, 2007[16]) and thus, so long the geometry is properly scaled the model should represent adequately the permeability in the prototype (i.e., so long the dimensions, placement and shape, also related to filling percentage, are scaled down correctly). At last, requirements as regard to geotextile sand tightness were considered.In regard to laboratory effects the following potential sources of error were examined: wave generation;

  • resonant oscillations forced across the boundaries of the test section;

  • absorption of reflected waves;

  • blockage effects;

  • compaction of sediments in the bed; and

  • accuracy of the instruments.

Resonant oscillations across the boundaries of the test section, and absorption of reflected waves have been examined. In addition, the evaluation of generated wave conditions based on the wave-data recorded during the experiments assured that the different models have been set-up to run on similar hydrodynamic conditions and thus that the comparison applied to the wave-induced morphodynamic change was possible and reliable. Representative sea-states were chosen from the prototype; in addition, the use of irregular wave trains also avoids the model effects of regular wave generation in coastal sediment models.Blockage effects around the structures were minimal, as only the array of four wave probes were at the flow section during the experiments. The pore-pressure sensors were buried into the sand at sufficient depth so that they would not emerge due to bottom erosion.For each wave run-segment with plane beach, the bed conditions were thoroughly checked before the experiment and the bed was carefully levelled to the desired gradient. To minimize the effects caused by the initial bed profile, the sand bed was repeatedly levelled until the measured beach-profile was within a minimum tolerance range based on the ideal conditions. To prevent disturbances and to assure that the level of sand saturation was roughly the same for each wave-run segment with plane beach, the water during levelling was kept to SWL. Above it, the beach-profile was slowly wet so as to reduce air entrainment.Coastal Sediment TransportA medium to long-term coastline evolution numerical model was developed that may be of important usage, namely, for the test and comparison of interventions to control erosion. The model assumes that long-shore transport is the most relevant governing process and incorporates a bottom updating scheme, based on pre-defined rules for cross-shore profile development. The critical analysis of its performance both in generic tests and in applications to real situations showed the need to improve the numerical description cross profile development. 041b061a72


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