99 results about "Spiral trajectory" patented technology

High speed removal of material from a specimen employs a beam positioner for directing a laser beam axis along various circular and spiral laser tool patterns. A preferred method of material removal entails causing relative movement between the axis of the beam and the specimen, directing the beam axis at an entry segment acceleration and along an entry trajectory to an entry position within the specimen at which laser beam pulse emissions are initiated, moving the beam axis at a circular perimeter acceleration within the specimen to remove material along a circular segment of the specimen, and setting the entry segment acceleration to less than twice the circular perimeter acceleration.

High speed removal of material from a specimen employs a beam positioner for directing a laser beam axis along various circular and spiral laser tool patterns. A preferred method of material removal entails causing relative movement between the axis of the beam and the specimen, directing the beam axis at an entry segment acceleration and along an entry trajectory to an entry position within the specimen at which laser beam pulse emissions are initiated, moving the beam axis at a circular perimeter acceleration within the specimen to remove material along a circular segment of the specimen, and setting the entry segment acceleration to less than twice the circular perimeter acceleration.

The present invention is directed to a turbine comprising a plurality of blades that rotate in a single direction when exposed to fluid flow, wherein the plurality of blades are joined to the central shaft by a plurality of radial spokes disposed substantially perpendicular to the central shaft such that the rotating plurality of blades causes the shaft to rotate. The plurality of blades has a uniform airfoil-shaped cross section, where the airfoil cross section presents a non-zero angle of attack to the current. The plurality of blades wind in a spiral trajectory, rotating around the central shaft and having a variable radius along the length of the central shaft such that a distance measured from the plurality of blades to the center shaft is greater near the center of the turbine than at either end.

A novel instrument and method for TOF / TOF mass spectrometry is offered. A spiral trajectory time-of-flight mass spectrometer satisfies the spatial focusing conditions for the direction of flight and a direction orthogonal to the direction of flight whenever ions make a turn in the spiral trajectory. An ion gate for selecting precursor ions is placed in the spiral trajectory of the spiral trajectory time-of-flight mass spectrometer. Electric sectors are placed downstream of the ion gate.

The method serves to place a space vehicle, such as a satellite, on a target orbit such as the orbit adapted to normal operation of the space vehicle and starting from an elliptical initial orbit that is significantly different from, and in particular more eccentric than the target orbit. The space vehicle is caused to describe a spiral trajectory made up of a plurality of intermediate orbits while a set of high specific impulse thrusters mounted on the space vehicle are fired continuously and without interruption, thereby causing the spiral trajectory to vary so that on each successive revolution, at least during a first stage of the maneuver, perigee altitude increases, apogee altitude varies in a desired direction, and any difference in inclination between the intermediate orbit and the target orbit is decreased, after which, at least during a second stage of the maneuver, changes in perigee altitude and in apogee altitude are controlled individually in predetermined constant directions, while any difference in inclination between the intermediate orbit and the target orbit continues to be reduced until the apogee altitude, the perigee altitude, and the orbital inclination of an intermediate orbit of the space vehicle have substantially the values of the target orbit.

In the present invention, firstly angle and distance indexes are established to image element array for a series of projection image data collected along circular or spiral trajectory according to data collection parameter and imaging system parameter of X ray and to carry on index ordering storage in order to make convenience for quickly seeking, then image angle and distance parameter on stereo-image pair which needs to be synthesized is calculated out according to selected viewing visual point, visual direction and visual difference effect so storage index and corresponding image data are seeked for carrying on image synthesis as per abovementioned information.

The present invention relies on a band moiré image layout model capable of predicting the band moiré image layer layout produced when superposing a base band grating layer of a given layout and revealing line grating layer of a given layout. Both the base band grating layer and the revealing line grating layer may have a rectilinear or a curvilinear layout. The resulting band moiré image layout may also be rectilinear or curvilinear. Thanks to the band moiré image layout model, one can choose the layout of two layers selected from the set of base band grating layer, revealing line grating layer and band moiré image layer and obtain the layout of the third layer by computation, i.e. automatically. In the case of a concentric band moiré image, base band grating layer and revealing line grating layer layouts may be produced according to geometric transformations, which yield, upon relative displacement of the position sampled by the revealing layer on the base layer, a band moiré image whose patterns move either radially, circularly or according to a spiral trajectory, depending on the orientation of the base band replication vector in the original non-transformed base layer space. In addition, it is possible to conceive a revealing line grating layer which when translated on top of the base band grating layer, generates a band moiré image which is subject to a periodic deformation. Furthermore, thanks also to the availability of a large number of geometric transformations and transformation variants (i.e. different values for the transformation constants), one may create documents having their own individualized document protection. The base band layer and the revealing layer may be separated by a small gap and form a fixed composed layer, where, thanks to the well-known parallax effect, by tilting the composed layer in respect to an observer, different positions of the base layer are sampled and a dynamically moving moiré image is generated. A computing system may automatically generate upon request an individualized protected security document having specific base band grating and revealing line grating layouts. The computing system may then upon request generate and issue a security document incorporating the base band grating layer, a base band grating layer or a revealing line grating layer allowing to authenticate a previously issued security document. The presented methods may be used for creating an individualized protection for various categories of documents (banknotes, identity documents, checks, diploma, travel documents, tickets) and valuable products (optical disks, CDs, DVDs, CD-ROMs, packages for medical drugs, products with affixed labels, watches).

A method of chemical species suppression for MRI imaging of a scanned object region including acquiring K space data at a first TE, acquiring K space data at a second TE, reconstructing images having off resonance effects, estimating off resonance effects at locations throughout the reconstructed image, and determining the first and second chemical species signals at image locations of the scanned object from the acquired signals and correcting for blurring resulting from off resonance effects due to B0 inhomogeneity.

Spiral imaging has recently gained acceptance for rapid MR data acquisition. One of the main disadvantages of spiral imaging, however, is blurring artifacts due to off-resonance effects. Dixon techniques have been developed as methods of water-fat signal decomposition in rectilinear sampling schemes, and they can produce unequivocal water-fat signal decomposition even in the presence of B0 inhomogeneity. Three-point and two-point Dixon techniques can be extended to conventional spiral and variable-density spiral data acquisitions for unambiguous water-fat decomposition with off-resonance blurring correction. In the spiral three-point Dixon technique, water-fat signal decomposition and image deblurring are performed based on the frequency maps that are directly derived from the acquired images. In the spiral two-point Dixon technique, several predetermined frequencies are tested to create a frequency map. The techniques can achieve more effective and more uniform fat signal suppression when compared to the conventional spiral acquisition method with SPSP pulses.

The method serves to place a space vehicle, such as a satellite, on a target orbit such as the orbit adapted to normal operation of the space vehicle and starting from an elliptical initial orbit that is significantly different from, and in particular more eccentric than the target orbit. The space vehicle is caused to describe a spiral trajectory made up of a plurality of intermediate orbits while a set of high specific impulse thrusters mounted on the space vehicle are fired continuously and without interruption, thereby causing the spiral trajectory to vary so that on each successive revolution, at least during a first stage of the maneuver, perigee altitude increases, apogee altitude varies in a desired direction, and any difference in inclination between the intermediate orbit and the target orbit is decreased, after which, at least during a second stage of the maneuver, changes in perigee altitude and in apogee altitude are controlled individually in predetermined constant directions, while any difference in inclination between the intermediate orbit and the target orbit continues to be reduced until the apogee altitude, the perigee altitude, and the orbital inclination of an intermediate orbit of the space vehicle have substantially the values of the target orbit.

In a method for distortion correction in spiral magnetic resonance imaging, a first MR data set is acquired by scanning raw data space along a spiral trajectory beginning at a first point. A first complex MR image is determined from the first MR data set, which includes first phase information for image points of the first MR image. A second MR data set is acquired by scanning raw data space along the spiral trajectory beginning at a second point that differs from the first point. A second complex MR image is determined from the second MR data set, which includes second phase information for image points of the second MR image. A geometric distortion for image points of the first or second MR image is determined from the first and second phase information, for example with a PLACE method.

The present invention aims at synthesizing superposition images formed either by band moire shapes or by shape level lines for making the information forwarded by valuable articles or by time pieces such as watches and clocks more dynamic, as well as for improving their attractiveness and aesthetics. A further application is publicity. For synthesizing band moiré images, the present invention relies on a band moiré image layout model allowing to obtain the layout of the base the band grating, given the layouts of the band moire image and of the revealing line grating. Base and revealing layer layouts may be conceived to create band moiré image shapes whose patterns move e.g. radially, circularly, or according to a spiral trajectory. Shape level lines occur in a superposition image when e.g. a base layer comprising modified sets of lines is superposed with a revealing layer comprising a line grating. Such a base layer embeds a shape elevation profile generated from an initial motif shape image (e.g. typographic characters, words of text, symbols, logo, ornament). By moving the revealing layer in superposition with the base layer, shape level lines move dynamically between the initial motif shape boundaries and shape foreground centers, respectively shape background centers, thereby growing and shrinking. The movement of the shape level lines creates visually attractive pulsing motif shapes, e.g. a pulsing heart or pulsing text. Categories of embodiments comprise (1) visually attractive articles having moving parts (watches, clocks, vehicles, publicity display devices, fashion clothes), (2) articles such as cosmetics, drugs, perfumes and wines, where one part is moved in respect to a second part, e.g. bottles having a lid or labels composed of two layers, (3) articles where the base layer and the revealing line grating are separated by a gap and form a fixed composed layer, and (4) articles where at least one of the layers is an electronic display.

In a method and apparatus for accelerated spiral-coded imaging (scanning k-space with a spiral trajectory) in magnetic resonance tomography, the user-defined sequence forming the basis of the spiral scanning is modified such that the k-matrix forming the basis of the sequence is scanned only in a sub-region, the sub-region being defined by a symmetrical shortening on both sides of the k-space matrix in a first direction as well as by a one-sided shortening of the k-space matrix in a second direction orthogonal to the first direction.

The invention discloses a flounder-type underwater glider. An electronic cabin comprises a pressure-resisting cabin, a gravity and gravity center adjustment mechanism, a control system and a lithium battery unit. The inside of the pressure-resist cabin is partitioned into a central area, a middle circular area and an outer circular area. The lithium battery unit is arranged in the middle circular area. The control system includes an overwater control system and an underwater control system which are connected in a wireless manner. The underwater control system and the electronic part of surveying equipment are arranged in the middle circular area uniformly. The gravity and gravity center adjustment mechanism comprises four water bag pump units in same structure, and the four water bag pump units are distributed in the outer circular area symmetrically. The flounder-type underwater glider has the advantages of low cost, low noise, high endurance and high flexibility; the gravity and posture of the glider can be adjusted to realize zigzag or spiral trajectory through controlling the four water bag pump units distributed symmetrically. The flounder-type underwater glider can carry a plurality of underwater scientific-investigation and survey devices simultaneously, continuous data collection in extensive sea areas can be completed automatically, and the data can be transmitted back in real time.

The invention discloses an imaging method. The imaging method comprises the following steps: putting an object in a detection region, and biasing a detector; moving an imaging system along a longitudinal Z axis; enabling a ray source and a detector to synchronously move along the periphery of the object, scanning and acquiring data, and performing completion and faultage according to the data. According to the imaging method disclosed by the invention, the detector biasing and spiral trajectory scanning are combined to solve a problem that an image assembly method used by a conventional CT (computed tomography) imaging (particularly cone-beam CT imaging) generates artifact on the assembly image for the cone-beam CT covered by a long Z axis, so that a usage area of the detector is reduced, and the system cost is saved.

The present invention is directed to a method of manufacturing a turbine blade. The method comprises selecting a pipe having a specific inner diameter, length and wall thickness, cutting the pipe along a spiral trajectory to produce a coil, securing the coil, and shaping the coil to create a uniform hydrofoil cross section along the length of the coil.

A novel instrument and method for TOF / TOF mass spectrometry is offered. A spiral trajectory time-of-flight mass spectrometer satisfies the spatial focusing conditions for the direction of flight and a direction orthogonal to the direction of flight whenever ions make a turn in the spiral trajectory. An ion gate for selecting precursor ions is placed in the spiral trajectory of the spiral trajectory time-of-flight mass spectrometer. Electric sectors are placed downstream of the ion gate.

An MRI image from spiral trajectory scanning is arranged as complementary subsets of values in time-sampled k-space. These values are Fourier transformed to produce a spatial domain image. While holding the patient stationary, the contrast information is updated at the central portion of k-space, and the peripheral portion of k-space data can be filled during the whole image acquisition. The contrast information is combined with the peripheral portion of k-space (contributing to image resolution) to construct a full k-space data and to generate a spatial image. The technique is useful for providing short time interval sampling when analyzing the take-up and fade-away of a contrast agent over time.

The present invention relates to a cooling apparatus for an electronic device. In the present invention, a coolant passing through a condenser 10 is introduced into and s filled in a compensator 15. The coolant passing through the compensator 15 is introduced into a vaporizer 20 and vaporized through heat exchange with an auxiliary heat source H2 provided outside of the vaporizer. In addition, a vaporizing unit 22 made of a porous material is provided in the vaporizer 20. The coolant passing through the vaporizer 20 and a liquid coolant supplied from the condenser 10 are mixed in a vortex generating unit 30 to form a coolant spray, and the coolant spray moves along a spiral trajectory to be formed into a vortex. Meanwhile, the coolant spray of a vortex is injected to be in close contact with the inner wall of an evaporator 50 to be heat-exchanged with a main heat source H1 positioned outside of the evaporator, thereby cooling the main heat source H1. According to the present invention as mentioned above, the main heat source adjacent to the evaporator is heat-exchanged with the coolant more actively to thereby improve the cooling performance of the electronic device. Also, a pressure loss of the coolant spouted from the venturi tube is further reduced.

The invention relates to a construction method of a time-varying dynamic model for high-feed turning of external thread members; the method comprises the steps of I, using, based on the Rayleigh beam vibration theory, a nose track spiral line equation as an integration object to solve a workpiece strain energy and kinetic energy equation for a tool that performs cutting along the nose spiral track; II, considering, based on an established tool instant cutting force model, the impact of 'quasi-regeneration effect' upon instant cutting force for turning a large-pitch thread member so as to correct the existing instant cutting force model and perform numerical solution; III, describing boundary conditions of thread member turning through a vibration mode function, and performing solving; IV, establishing and solving a workpiece vibration model according to the virtual work principle and the method of separation of variables. The large-pitch external thread member vibration equation established herein is capable of predicting a sharply varying position of a workpiece upon vibration and displacement, and can assist in adjusting and optimizing parameters of a machining process for large-pitch thread members.

The invention discloses a high-availability data collection method based on multiple AUVs in an underwater sensor network. The method comprises the following steps: constructing an underwater sensor network model, patrolling, by a plurality of autonomous underwater vehicles AUVs, in the network according to a predefined spiral trajectory for data collection, and periodically adjusting the patrol trajectory; and calculating, by a node, whether itself is within the collection area of one or more autonomous underwater vehicles AUVs according to own location and the trajectories of the autonomousunderwater vehicles AUVs. The node within the collection area performs communication after the autonomous underwater vehicle AUV arriving at the vicinity of the node to upload data; and the node beyond the collection area forwards the data to the node within the collection area through multiple hops. When the autonomous underwater vehicle AUV is faulty, a gateway node discovering the fault broadcasts a control packet and performs fault processing. By adoption of the high-availability data collection method, the energy consumption and the communication overhead of the node are reduced, and thehigh availability of the network is guaranteed.

A method is disclosed for generating computer tomography images using a 3D image reconstruction method. According to the method, to scan an object to be examined using a cone-shaped bundle of rays originating from a focal point and a planar, preferably multi-line detector for detecting the bundle of rays, the focal point is displaced along a spiral trajectory around the object to be examined. The detector delivers output data corresponding to the detected radiation and image voxels from the scanned examined object are reconstructed from the optionally pre-processed output data, the image voxels reflecting the attenuation coefficients of the respective voxel. Each image voxel is reconstructed separately from projection data, which covers a projection angular range of at least 108° and an approximate weighting is carried out for each voxel considered in order to standardize the projection data using the voxel.

A turbine includes a plurality of blades that rotate in a single direction when exposed to fluid flow, wherein the plurality of blades are joined to the central shaft by a plurality of radial spokes disposed substantially perpendicular to the central shaft such that the rotating plurality of blades causes the shaft to rotate. The plurality of blades has a uniform airfoil-shaped cross section, where the airfoil cross section presents a non-zero angle of attack to the current. The plurality of blades wind in a spiral trajectory, rotating around the central shaft and having a variable radius along the length of the central shaft such that a distance measured from the plurality of blades to the center shaft is greater near the center of the turbine than at either end.

A method for manufacturing a circular metal tank, from an elongated sheet of metal. The upper and lower longitudinal edges of the metal sheet are bent to produce a first “L” bend and a second “chair” bend, respectively. The sheet of metal is moved in a helical trajectory such that the second bend comes into proximity above the first bend. The second bend and the first bend are welded together such that the wall of the cylindrical tank is formed. Welding of the bends serves to stress relieve or anneal the bent metal, thereby preventing cracks in the metal which may result in leaks and / or compromise the structural integrity of the tank. The first and second bends additionally cooperate to form a helical roller track on the outside of the tank. The tank is supported and rotated about its longitudinal axis on a plurality of rollers that engage the roller track.

A modified projection on convex sets (POCS) algorithm and method for partial k-space reconstruction using low resolution phase maps for scaling full sets of reconstructed k-space data. The algorithm can be used with partial k-space trajectories in which the trajectories share a common point such as the origin of k-space, including variable-density spiral trajectories, projection reconstruction trajectories with a semicircle region acquisition, and projection reconstruction trajectories with every other spike acquired.

The invention relates to a method for distortion correction in spiral magnetic resonance imaging, radial magnetic resonance imaging and echo planar imaging. In a method for distortion correction in spiral magnetic resonance imaging, a first MR data set is acquired by scanning raw data space along a spiral trajectory beginning at a first point. A first complex MR image is determined from the first MR data set, which includes first phase information for image points of the first MR image. A second MR data set is acquired by scanning raw data space along the spiral trajectory beginning at a second point that differs from the first point. A second complex MR image is determined from the second MR data set, which includes second phase information for image points of the second MR image. A geometric distortion for image points of the first or second MR image is determined from the first and second phase information, for example with a PLACE method.

The present invention is directed to a method of manufacturing a turbine blade. The method comprises selecting a pipe having a specific inner diameter, length and wall thickness, cutting the pipe along a spiral trajectory to produce a coil, securing the coil, and shaping the coil to create a uniform hydrofoil cross section along the length of the coil.

The invention discloses a data collection method based on multi-AUV position prediction in an underwater acoustic sensor network. The method comprises the steps that multiple AUVs cruise in the network according to a predefined spiral trajectory to perform data collection, and the trajectory can be adjusted; the positions and the time for each AUV to enter the network are different; the node comprehensively considers the distance between the node and the AUV and the duration required by the AUV to reach the water surface to select the target AUV; and a neighbor node is selected, and the data is sent to the target AUV through multiple hops. According to the invention, a multi-AUV cruise network is supported for data collection, and the energy consumption of nodes is reduced; and the AUV does not need to broadcast a control packet during network cruising, so that the communication overhead is reduced.

The invention discloses a method for enhancing the transverse strength of an FRP (fiber reinforced plastics) pultruded profile by utilizing a weaving technology, relates to a method for enhancing an FRP material, and aims to solve the problem of low transverse strength of the FRP pultruded profile prepared by a conventional method. The method comprises the following steps of 1, preparing a resin substrate; 2, drying and arranging fibers; 3, wetting the fibers; 4, pre-forming longitudinal fibers; 5, weaving a surface layer; 6, pre-forming a woven layer; and 7, performing solidification shaping. The method for enhancing the transverse strength of the FRP pultruded profile by utilizing the weaving technology has the advantages that the transverse tensile strength of the prepared FRP pultruded profile reaches 50 to 90MPa, and is improved by 20 to 50 percent compared with that of the FRP pultruded profile prepared by the conventional method; the longitudinal tensile strength of the FRP pultruded profile reaches 600 to 900MPa; the surface layer fibers of the pultruded profile form a spiral trajectory, and are interwoven into a seamless whole.

The invention provides an in-place precision measurement method for a three-dimensional shape error of an aspheric grinding circular arc diamond grinding wheel. The in-place precision measurement method comprises the steps that (1) height data of all points on the surface of the grinding wheel are spirally and continuously scanned and measured; (2) the data are subjected to interpolation fitting treatment according to a spiral trajectory model, a three-dimensional geometrical morphology matrix on the surface of the grinding wheel is obtained, and least square circular arc fitting is conducted, so that the circular arc radius, the circular arc center coordinate and the circular arc center deviation of the grinding wheel are obtained; (3) an average three-dimensional geometrical morphology matrix on the surface of the grinding wheel is established and subtracted from the morphology matrix, and a three-dimensional error distribution matrix, a circular arc degree error and a radial run-out error are obtained; and (4) outer circumference height data of the grinding wheel are measured, and the basic part radius of the grinding wheel is obtained through least square circular arc fitting. According to the in-place precision measurement method for the three-dimensional shape error of the aspheric grinding circular arc diamond grinding wheel, efficient precision non-contact measurement of all the important geometrical parameters of the circular arc diamond grinding wheel is achieved, and the measurement results can be directly used for precise interpolation calculation of aspheric optical element ultra-precision grinding machining grinding wheel movement control point coordinates.