Abstract: A calibration method for an x-ray computerized tomography system and a method of tomographic reconstruction are provided. The calibration method includes steps of measuring at least one point spread function (PSF) at each of a plurality of points, compressing each PSF, and in one or more storing operations, storing the compressed PSFs in a computer-accessible storage medium. The PSF measurements are made in a grid of calibration points in a field of view (FOV) of the system. In the measuring step, an absorber is positioned at each of the calibration points, and an x-ray projection is taken at least once at each of those absorber positions. In the method of tomographic image reconstruction, projection data from an x-ray tomographic projection system are input to an iterative image reconstruction algorithm.

Abstract: A membrane assembly 150 for a variable focusing power optical assembly 100 comprising a distensible membrane 155 that is held under tension around its periphery by at least one bendable support ring 159 and one or more curvature controllers 170 that are mounted to respective discrete sections of the support ring 159 for actively controlling the curvature of those sections of the ring in a plane (Btz) that is parallel to a z-axis normal to an (x,y) plane which is defined by the un-deformed support ring and tangential (t) to the periphery (boundary B) of the membrane.

Abstract: A method of fabricating a lens element for an adjustable power lens of the kind comprising two lens elements that are slidable relative to one other in a direction transverse the optical axis of the lens and have respective lens surfaces that are shaped to act together to form a corrective lens, the power of which varies according to the relative disposition of the two lens elements, the method comprising the steps of forming a lens puck having two opposite faces, which are shaped to form opposite lens surfaces of one of the lens elements of the adjustable power lens, the puck having at least one alignment feature, and thereafter edging the puck to a desired eye shape with reference to the alignment feature.

Abstract: A method of fabricating a lens element for an adjustable power lens of the kind comprising two lens elements that are slidable relative to one other in a direction transverse the optical axis of the lens and have respective lens surfaces that are shaped to act together to form a corrective lens, the power of which varies according to the relative disposition of the two lens elements, the method comprising the steps of forming a lens puck having two opposite faces, which are shaped to form opposite lens surfaces of one of the lens elements of the adjustable power lens, the puck having at least one alignment feature, and thereafter edging the puck to a desired eye shape with reference to the alignment feature.

Abstract: Illustrative embodiments are directed to a method and apparatus for evaluating boundary detection in an image. A processed image is received, wherein a detected boundary of an image of an object is identified in the processed image. A Radon transform is applied to the processed image for a plurality of angles to form a processed image histogram corresponding to the detected boundary for each of the plurality of angles. The processed image histogram for each of the plurality of angles and a corresponding ground truth histogram for each of the plurality of angles is normalized to provide a normalized processed image histogram and a normalized ground truth histogram for each of the plurality of angles, wherein the ground truth histogram corresponds to a ground truth boundary of the object for a corresponding angle. An indication of the edges of the normalized processed image histogram for each of the plurality of angles is plotted to form a boundary detection evaluation visualization.

Abstract: A membrane assembly (150) for a variable focusing power optical assembly (100) comprising a distensible membrane (155) that is held under tension around its periphery by at least one bendable support ring (159) and one or more curvature controllers (170) that are mounted to respective discrete sections of the support ring (159) for actively controlling the curvature of those sections of the ring in a plane (Btz) that is parallel to a z-axis normal to an (x,y) plane which is defined by the un-deformed support ring and tangential (t) to the periphery (boundary B) of the membrane.

Abstract: A composition and process to make polyurethane foam using a stable liquid catalyst composition comprising at least one liquid bismuth carboxylate catalyst and at least one liquid dialkyltin dicarboxylate complex are disclosed. The disclosed composition and process yield polyurethane foam having favorable properties, but requiring less metal. The polyurethane foams produced by this catalyst composition and method are useful for laminated boardstock, construction panels, appliance insulation, spray-applied insulation, seat cushions, and mattresses.

Abstract: Illustrative embodiments are directed to a method and apparatus for evaluating boundary detection in an image. A processed image is received, wherein a detected boundary of an image of an object is identified in the processed image. A Radon transform is applied to the processed image for a plurality of angles to form a processed image histogram corresponding to the detected boundary for each of the plurality of angles. The processed image histogram for each of the plurality of angles and a corresponding ground truth histogram for each of the plurality of angles is normalized to provide a normalized processed image histogram and a normalized ground truth histogram for each of the plurality of angles, wherein the ground truth histogram corresponds to a ground truth boundary of the object for a corresponding angle. An indication of the edges of the normalized processed image histogram for each of the plurality of angles is plotted to form a boundary detection evaluation visualization.

Abstract: An augmented reality display unit for use in an augmented reality headset or the like comprising front and rear variable focusing power compression liquid lens assemblies (220, 230) in mutual optical alignment on an optical axis (O), a transparent waveguide display (240) interposed between the front and rear liquid lens assemblies (220, 230) and a selectively operable adjustment mechanism for adjusting the focusing powers of the front and rear compression liquid lens assemblies (220, 230); wherein each of the front and rear compression liquid lens assemblies (220, 230) comprises a fluid-filled envelope (225, 235) having a first wall formed by a distensible elastic membrane (226, 236) that is held under tension around its edge by a peripheral support ring, a second substantially rigid wall (223, 233) formed by or supported on an inner surface of a transparent plate or a hard lens of fixed focusing power, and a collapsible side wall (227, 237), the membrane forming an optical surface of variable optical power,

Abstract: An example device includes a fluid lens, where the fluid lens includes a membrane, a substrate, and a fluid located within an enclosure formed at least in part by the membrane and the substrate. The membrane may be an elastic membrane. The fluid may include an amount of an additive that is effective to appreciably reduce bubble formation within the fluid, such as when a negative pressure is applied to the fluid. In some examples, the additive may include particles, such as nanoparticles. The additive may include a thixotropic agent that helps to impart an appreciable thixotropic property to the fluid. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: In some examples, a device, such as an augmented reality or virtual reality device, may include one or more waveguide displays and one or more adjustable lenses, such as adjustable fluid lenses. In some examples, a device includes a waveguide display and a rear lens assembly that together provide a negative optical power for augmented reality light. A front lens assembly, the waveguide display, and the rear lens assembly may together provide an approximately zero optical power for real-world light. In some examples, an eye-side optical element having a negative optical power may defocus light from the waveguide display. Example devices may allow the adjustable lens (or lenses) to have a reduced mass and/or a faster response time.

Abstract: A panel, which, at two opposite edges, is provided with coupling parts that allow joining by a downward movement, the coupling parts including a male part that fits in a female part, wherein vertically active locking portions are provided at opposite sides of the male part and female part, wherein these locking portions are located at different distances from an upper side of the panels.

Abstract: A method of assembling an adjustable fluid-filled lens assembly comprising biaxially tensioning an elastomeric membrane to a surface tension of greater than 180 N/m, typically greater than 1000 N/m; thermally conditioning the tensioned membrane, e.g., for one hour at a temperature of about 80° C., to accelerate relaxation of the membrane; mounting the membrane to a peripheral support structure whilst maintaining the tension in the membrane; assembling the mounted membrane with one or more other components to form an enclosure with the membrane forming one wall of the enclosure; and thereafter filling the enclosure with a fluid. The membrane may be formed from an aromatic polyurethane, and the fluid may be a phenylated siloxane. In some embodiments, the membrane is able to hold a substantially constant surface tension of at least 180 N/m for a period of at least 12 months.

Abstract: An adjustable fluid-filled lens or minor assembly 100 comprising a fluid-filled envelope and a supporting structure therefor; the fluid-filled envelope being constituted by a first wall that is formed of a distensible elastic membrane 15 having an exterior optical surface of variable focusing power, a second wall 18 that is spaced from the first wall on a z-axis, and a collapsible peripheral side wall 17 that extends between the first and second walls, and being filled with a substantially incompressible fluid 16; a membrane holding structure 14 that is attached to a peripheral edge of membrane 15 for holding the membrane under tension; and one or more selectively operable actuator assemblies r1, r2, r3 for moving one or more corresponding regions of the peripheral edge of the membrane on the z-axis towards and away from the second wall 18 for controlling the profile of the peripheral edge of the membrane; wherein the or each actuator assembly comprises a connecting member 91, 92, 93 that is attached to the m

Abstract: A method is provided for isolating and labeling discrete features in a spectral radiographic image recorded as a set of images in different energy channels. The disclosed method involves creating a profile for each of at least some pixels in the spectral radiographic image. The profiles are sequences of pixel values, in which each pixel value is a photon count or a similar radiographic exposure value indicative of the attenuation of a portion of the scanning beam in a respective energy channel. Iterative hierarchical clustering is used to cluster the pixels on the basis of their respective profiles. Labels are assigned to one or more of the resulting clusters. In implementations, each label can be associated with an inferred material composition or with an inference that the material composition is unknown.

Abstract: Methods of filling an envelope (16) of a compression-type adjustable optical device (10), such as a liquid lens or mirror, which is formed in part by a distensible membrane (11) having an exterior optical surface, with a substantially incompressible fluid (15) to a predetermined optical power or radius of curvature; the methods comprising pumping fluid into the envelope (16) under vacuum through a fluid supply conduit (23) in fluid communication with an interior of the envelope (16) while allowing air to escape from the envelope through a fluid overflow conduit (26) in fluid communication with the interior of the envelope (16); continuing to pump fluid (15) into the envelope (16) to cause the membrane (11) to distend to an optical power of the optical device (10) that is greater than the predetermined optical power while allowing excess fluid (15) to escape from the envelope through the overflow device (26); slowing or stopping the supply of fluid to the envelope (16), thereby to allow the membrane (11) progr

Abstract: A variable focusing power fluid-filled lens or minor assembly (100a) comprising a fluid-filled envelope and a supporting structure (18) therefor; the fluid-filled envelope being constituted by a first wall that is formed of a distensible elastic membrane (15) having an exterior optical surface (151) of variable focusing power, a second wall (183) that is spaced from the first wall on a z-axis which is generally perpendicular to the membrane, and a collapsible peripheral side wall (17) that extends between the first and second walls (15, 183), and being filled with a substantially incompressible fluid (16); a membrane holding structure (14) that is attached to a peripheral edge of membrane for holding the membrane under tension, the membrane holding structure defining a plurality of discrete control points spaced around the peripheral edge of membrane where the position of the peripheral edge of the membrane relative to the second wall on the z-axis is controlled and permitting bending of the peripheral edge o

Abstract: Embodiments of a method (e.g., for operating a robotic device such as a dog device, etc.) can include: receiving one or more inputs (e.g., sensor input data, etc.) at a dog device (e.g., at one or more sensors of the dog device; a robotic dog device; etc.) from one or more users and/or other suitable entities (e.g., additional dog devices; etc.); determining one or more events (and/or a lack of one or more events), such as based on the one or more inputs (and/or a lack of one or more inputs); processing (e.g., determining, implementing, etc.) one or more scenes based on the one or more events (and/or lack of one or more events); and/or performing one or more output actions with the dog device, based on the one or more scenes (e.g., individual scenes; scene flows; etc.).

Abstract: A panel, which, at two opposite edges, is provided with coupling parts that allow joining by a downward movement, the coupling parts including a male part that fits in a female part, wherein vertically active locking portions are provided at opposite sides of the male part and female part, wherein these locking portions are located at different distances from an upper side of the panels.

Abstract: A method of assembling an adjustable fluid-filled lens assembly comprising biaxially tensioning an elastomeric membrane to a surface tension of greater than 180 N/m, typically greater than 1000 N/m; thermally conditioning the tensioned membrane, e.g., for one hour at a temperature of about 80° C., to accelerate relaxation of the membrane; mounting the membrane to a peripheral support structure whilst maintaining the tension in the membrane; assembling the mounted membrane with one or more other components to form an enclosure with the membrane forming one wall of the enclosure; and thereafter filling the enclosure with a fluid. The membrane may be formed from an aromatic polyurethane, and the fluid may be a phenylated siloxane. In some embodiments, the membrane is able to hold a substantially constant surface tension of at least 180 N/m for a period of at least 12 months.