63 results about "Numerical reconstruction" patented technology

A series of holograms is recorded by synchronizing a camera with laser pulses under the control of a digital delay generator. Amplitude and phase images are calculated while image distances are adjusted for the best focus on the object under observation. The amplitude and phase images are reconstructed while adjusting the image distances over a predetermined range to maintain the object in focus. Numerical superposition of a plurality of holographic fields taken with varying wavelengths provides high resolution microscopic three-dimensional imaging. Numerical reconstruction is based on an angular spectrum method that enables calculation of the image at any distance from the hologram plane. Wavelength scanning digital interference holography also enables image reconstruction along an arbitrarily tilted plane.

A method of security screening and inspection of people in airlines, ships, or secured buildings, involves placing an array of transmitters and receivers in operational association with the medium. The transmitters generate a broad band harmonic (frequency domain) or pulse (time domain) primary electromagnetic field (EM) field, including the lower frequency portions of the EM spectrum, whose propagation is typically characterized by the diffusion phenomena, or by the combination of the diffusion and wave phenomena. The primary field propagates through and interacts with the examined person and any objects carried by the person to produce a scattered field, which is recorded by the receivers. The scattered EM field components measured by the receivers are applied as an artificial EM field to generate a backscattering EM field. Cross power spectra of the primary and backscattering fields (in the frequency domain) or cross correlation between these fields (in the time domain) produce a numerical reconstruction of an EM hologram. The desired properties of the person, including the properties of any objects carried by the person, such as conductivity or dielectric permittivity, are then derived from this hologram.

The present invention provides for a digital holographic microscope using a holographic interferometer and incorporating a TIR sample mount and microscopic imaging optics. The microscope uses phase shifting from frustrated internal reflection within a prism to measure nanometric distances. The invention also provides for a numerical reconstruction algorithm of an inclined surface of the object / prism.

The invention discloses a method and system for measuring a polarization state of a sample based on a polarization beam splitting prism. After light emitted by a laser device is aligned through an alignment device, the light is split into two beams through a non-polarization beam splitting prism, wherein one beam of light penetrates through a sample or carries sample information after being reflected by the sample and is used as an object light beam; the other beam of light is used as a reference light beam; the two beams of light are reflected through a reflecting mirror and then are converged through the non-polarization beam splitting prism. The polarization beam splitting prism is rotated so that the reference light beam is divided into two beams of linearly polarized light, which havebasically equal light intensity and crossed polarization directions, after passing through the polarization beam splitting prism. After the reference light beam and the object light beam pass throughthe polarization beam splitting prism, two interference patterns with orthogonal polarization states are formed. Two holograms are recorded by utilizing a camera. A computer is used for further carrying out numerical value reconstruction on complete unification positions and corresponding pixel points of the sample in the two holograms; finally, corresponding amplitude and phase information of anobject light wave field is finally obtained; the information is processed by the computer to obtain polarization state information of the sample. Compared with utilization of a traditional Mueller microscope, a condition that a plurality of times of acquisition are influenced by the environment is avoided and the stability and the real-time measurement capability of the system are improved.

A method for identifying a state of a cell contained in a sample, including: illuminating the sample using a light source by producing an incident light wave propagating toward the sample; then acquiring, using a matrix-array photodetector, an image of the sample, the sample being placed between the light source and the matrix-array photodetector such that the matrix-array photodetector is exposed to a light wave resulting from interference between the incident light wave and a diffraction wave produced by each cell; applying a numerical reconstruction algorithm to the image acquired by the matrix-array photodetector, to estimate a characteristic quantity of the light wave reaching the matrix-array detector, at a plurality of distances from the matrix-array photodetector. The value of the characteristic quantity, or its variation as a function of distance, allows the state of the cell to be determined from among predetermined states.

The invention relates to the technical field of computer vision, and particularly discloses a low-redundancy rapid reconstruction method for a plankton hologram comprising the following steps: S1, collecting a plankton digital hologram, and generating a source image data set; S2, calibrating plankton in each holographic source image in the source image data set to obtain a calibration data set; S3, training the established hologram reconstruction network by using the calibration data set, and testing the trained hologram reconstruction network by using the source image data set; and S4, using the tested hologram reconstruction network for reconstruction of other plankton holographic source images. The hologram reconstruction network can automatically detect an effective target area and reconstruct an area of interest. Compared with a traditional numerical reconstruction method, the hologram reconstruction network trained by the method is high in plankton hologram reconstruction speed and high in redundant information elimination efficiency, and is expected to play an important role in marine environment detection.

The present invention discloses a design method of a concrete block cooling system based on a fast and accurate numerical reconstruction technology, which takes the water pipe cooling effect in the concrete block as a negative heat source of the system, and takes the influence of cement hydration heat into account. The method comprises: configuring a plurality of test points inside and at the boundary of the inspected concrete block to obtain temperature values of the test points; establishing the equivalent control equation for the heat conduction problem, and obtaining a plurality of local low-order matrices according to the radial basis function collocation method; calculating shape parameters of the radial basis function by using the multi-scale algorithm; using the matrix sparse algorithm to construct the equation required by calculating the temperature field; calculating the temperature value of any inner point at any time; and determining the rationality of the cooling system scheme according to the maximum temperature difference between the inside and outside of the inspected structure. The method of the present invention is simple and efficient, and has the characteristicsof high precision, fast calculation, simple mathematics and a simple procedure; and the method conforms to the characteristic requirements of a fast, stable and accurate data reconstruction technology which is required in the design of the concrete block cooling system.

A method for identifying a particle contained in a sample, including illuminating the sample using a light source, the light source producing an incident light wave propagating toward the sample, then acquiring, using a matrix-array photodetector, an image of the sample, the sample being placed between the light source and the photodetector such that the matrix-array photodetector is exposed to a light wave that is the result of interference between the incident light wave and a diffraction wave produced by each particle. The method further includes applying a numerical reconstruction algorithm to the image acquired by the photodetector, to estimate a characteristic quantity of the light wave reaching the detector, at a plurality of distances from the detector. The variation in the characteristic quantity as a function of distance allows the particle to be identified.

The invention discloses a numerical reconstruction method for a residual stress field of a surface strengthening metal part. Based on commercial CAE-based software, compression stress is generated inthe reinforced layer region by using the temperature difference. Different temperature values are set for a material or a component strengthening layer and other areas respectively, so that residual compressive stress fields generated by different surface strengthening processes are simulated. Adjustment is carried out according to actually-measured component residual stress data.The residual compressive stress fields are matched with the residual stress gradient distribution of the actually-measured data and subsequent numerical simulation calculation is facilitated. According to the method,a relatively accurate result can be obtained, the universality is high, the efficiency is high, the economical efficiency is good, the simulation and design process is greatly simplified, and a residual compressive stress field conforming to actual measurement data can be rapidly and economically deduced in engineering application.