Abstract: A system for providing an object distance of a device under test (DUT), the system including a first lens, a second lens, an optical pinhole disposed between the first lens and the second lens, a detector and a pair of gratings disposed between the second lens and the detector, the detector configured for receiving a Moiré pattern formed as a result of light from the DUT being disposed through the first lens, the optical pinhole, the second lens and the pair of gratings, wherein the object distance is determined based on the Moiré pattern and one or more properties of the pair of gratings.

Abstract: A method for providing an object distance of a device under test (DUT) using a system including a first lens, a second lens, an optical pinhole disposed between the first lens and the second lens, a detector, a pair of gratings disposed between the second lens and the detector, the detector configured for receiving a Moiré pattern formed as a result of light from of the DUT being disposed through the first lens, the optical pinhole, the second lens and the pair of gratings, the method including obtaining the Moiré pattern using the detector and determining the object distance based on the Moiré pattern and one or more properties of the pair of gratings.

Abstract: An antenna includes a first radiator having a first end and a second end, where the second end or a middle position of the first radiator is grounded; a second radiator having a third end and a fourth end, the fourth end is disposed away from the first end relative to the third end, and the second end or a middle position of the second radiator is grounded; a feeding circuit configured to feed the first radiator and the second radiator, at the first end of the first radiator and the third end of the second radiator; and a tuning circuit configured to selectively connect the feeding circuit to the first end of the first radiator or the third end of the second radiator to feed the first radiator or the second radiator.

Abstract: A method for providing a virtual distance of a device under test using a system including a light source, a wedge shear plate, a first detector and a second detector, wherein the wedge shear plate is disposed between the device under test and the light source, the first detector configured for receiving a first interference pattern formed as a result of the light source being disposed through and reflected by the wedge shear plate, and the second detector configured for receiving a second interference pattern formed as a result of the light source being disposed through and reflected by the wedge shear plate, the method including obtaining the first interference pattern using the first detector, obtaining the second interference pattern using the second detector and determining the virtual distance based on the first interference pattern, the second interference pattern, the light source and the wedge shear plate.

Abstract: A computing device of a data register includes persistent storage and a data register manager. The persistent storage stores: an instance of a primary chain that specifies an organizational structure of computing devices of the data register and a secondary chain for registering data with a first portion of the computing devices. The data register manager monitors sizes of each of the portions of the computing devices specified by the organizational structure; makes a determination, based on the monitoring, that the organizational structure fails to meet at least one criteria; and in response to the determination: reorganizes the organizational structure to meet the at least one criteria by, at least in part, modifying the secondary chain.

Abstract: An example antenna system includes a first antenna including a strip-shaped antenna radiator. The antenna radiator has a first end and a second end. At least one of a first radiator section in which the first end is located or a second radiator section in which the second end is located is used as a radiator of a second antenna. One of two first filters is connected between the first antenna radio frequency source and an antenna feed point, and the other first filter is connected between a ground and an antenna ground point. One of two second filters is connected between the second antenna radio frequency source and at least one of the first radiator section or the second radiator section, and the other second filter is connected between the ground and at least one of the first radiator section or the second radiator section.

Abstract: An antenna apparatus includes a circuit board and an antenna body. The antenna body includes a first radiator and a second radiator that are indirectly coupled. The first radiator comprises a first stub and a second stub that are opposite to, but do not touch each other to form a first gap, the first stub and the second stub are located on a first side edge of the circuit board, a second gap is configured between the first stub and the first side edge, and also between the second stub and the first side edge. The second radiator is located on the circuit board to form a third gap in-between. A vertical projection of the second radiator is located on the first surface. The first stub and the second stub are electrically connected to reference ground of the circuit board separately.

Abstract: A wavefront calibration method for a wavefront tester of a lens, the method including: measuring an air wavefront of the wavefront tester without the lens; measuring at least one golden sample wavefront to generate an actual wedge angle and refractive index of the at least one golden sample based on the air wavefront; calculating a measured wedge angle and refractive index based on the actual wedge angle and refractive index of the at least one golden sample; and linear fitting between the actual wedge angle and refractive index and the measured wedge angle and refractive index to produce an actual magnification of the lens.

Abstract: Provided are a sampling object determination method and apparatus, an electronic device, and a computer-readable storage medium. The sampling object determination method includes: determining a sampling number through a sampling proportion and a total number of users of an application; determining at least one version in order of versions of the application from high to low, where a sum of a number of users of the at least one version is greater than or equal to the sampling number; and determining the sampling number of users in the users of the at least one version as sampling objects.

Abstract: An acoustic levitation apparatus and method for adaptively adjusting a resonance distance. The apparatus includes an acoustic receiver, an acoustic transmitter, a motor, a slide, and a signal feedback control module. The acoustic receiver and the acoustic transmitter are installed on the slide of which movement is controlled by the motor. The acoustic receiver is connected to the signal feedback control module. The signal feedback control module performs determination by detecting the magnitude of a signal outputted by the acoustic receiver and automatically controls the motor to adjust a spacing between the acoustic transmitter and the acoustic receiver to satisfy a resonance condition to form stable standing wave levitation. The acoustic transmitter is connected to an ultrasonic generator.

Abstract: An antenna apparatus and an electronic device. The antenna apparatus includes a feed source, a transmission line, a first radiator including a first feed point, and a second radiator including a second feed point. The transmission line is electrically connected to the feed source. A second end part of the second radiator is disposed away from the first radiator compared to the first end part of the second radiator, a first gap is formed between the first end part of the first radiator and the first end part of the second radiator, the first end part of the first radiator is a ground end, and the first end part of the second radiator is an open end. The two feed points are electrically connected to the transmission line, and the transmission line input a radio frequency signal in a same frequency band to the two feed points.

Abstract: According to embodiments of the present disclosure, a method, device and computer program product for information processing are proposed. The method comprises: obtaining identification information of a shard of metadata at a first node of a blockchain-based metadata management system; determining, based on similarities of the identification information of the shard and identification information of candidate nodes of the metadata management system, a second node for positioning the shard from the candidate nodes; and enabling the second node to process the identification information of the shard, to manage storage of the shard in the metadata management system. Therefore, the present solution can improve efficiency, security and robustness of the metadata management system.

Abstract: An antenna includes a first radiator, a second radiator, and a feed. The first radiator has a first feed point and a first ground point. The second radiator has a second feed point and a second ground point. The antenna further includes a connection line. The connection line has a first end and a second end that are opposite to each other. The first end is coupled to the first feed point of the first radiator, and the second end is coupled to the second feed point of the second radiator. A feeding point is disposed on the connection line, and the feeding point is coupled to the feed.

Abstract: An electromagnetic wave-trapping device including two surfaces, each disposed in a plane, the two surfaces disposed at a first angle with respect to one another to form an opening, one of the two surfaces is configured to be orientated such that an incident electromagnetic ray through the opening, is disposed at a second angle with respect to the one of the two surfaces.

Abstract: A prism module for enabling a large field of view high resolution sampling of incoming rays, the prism module including a plurality of elongated prisms disposed about a central axis, each of the prisms including a fore surface; an aft surface; and a reflecting surface connected on a first edge to the fore surface and connected on a second edge to the aft surface, wherein the fore surface is configured to receive the incoming light rays orthogonally disposed with respect to the fore surface, the reflecting surface configured to reflect the incoming light rays to cause outgoing light rays to exit at a right angle through the aft surface to form an image with a maximum distortion not recognizable by a human eye.

Abstract: A system for calibrating an equipment, the system including a beam splitter; a first reticle configured to be removably attached to the equipment; and an image capture device including an image plane, wherein an image of the first reticle is configured to be received by way of the beam splitter at the image plane along an optical axis of the beam splitter, wherein the orientation as indicated by the first reticle is compared to an orientation of the image plane and if the orientation as indicated by the first reticle differs from the orientation of the image plane, the equipment is rotated about the optical axis of the beam splitter such that the orientation as indicated by the first reticle matches the orientation of the image plane.

Abstract: A system for providing two parallel light beams spaced-apart a selectable distance, the system including: a first beam splitter configured for reflecting a light beam from a light source to create a first datum light beam, the first beam splitter is fixedly attached to a base; a second beam splitter configured for reflecting a transmitted light beam from the light beam from the light source to create a second datum light beam, a third beam splitter configured for reflecting a transmitted light beam from the light beam from the light source to create a third datum light beam, a fourth beam reflecting device configured for reflecting a transmitted light beam from the light beam from the light source to create a fourth light beam. Each of the second, third beam splitters and fourth beam reflecting device is configured to be slidingly attached to the base.