An improved conjugate gradient algorithm (ICGA) is presented to inverted particle size distribution (PSD) with ensemble light scattering methods. The narrow unimodal, broad unimodal, or the multipeak modal PSD can be inverted from diffraction data with ICGA. In the algorithm, a convergence threshold should be changed according to the particle size distribution width (PSDW). However, we cannot always know the PSDW beforehand, thus we propose to calculate the PSDW by the light-scattering data. Afterward, we can select the convergence threshold. We experimented on some samples and their mixture. The results show the proposed method can be applied to inverted PSD with different distribution models. The resulting errors on the above samples are within 4.55%. The mixture of some particulate certified reference materials can be discerned distinctly, thus the resulting resolutions are acceptable.
This paper presents an absolute phase calculation method from one composite RGB fringe pattern image by using
the windowed Fourier transform (WFT) algorithm and the optimum three-frequency selection method. Three fringe
patterns having the optimum fringe numbers are coded into the red, green and blue channels of a composite color
image. The generated composite RGB image is projected onto a measured object surface from a Digital Light
Processing (DLP) projector and the deformed fringe patterns captured by a color CCD camera from a different
viewpoint. The wrapped phase information will be calculated by the WFT algorithm. The WFT algorithm limits the
processed image to a small area, so it can give much better phase near edges or discontinuities than FT algorithm.
Applying the WFT algorithm to the three fringe patterns obtains three wrapped phase maps. An absolute phase map
is calculated pixel by pixel from one composite RGB fringe pattern image after applying the optimum threefrequency
selection method to the three obtained wrapped phase maps. Therefore, the proposed method can
measure absolute phase of objects having discontinuous surfaces from one snapshot image. Experimental results on
moving discontinuous objects show that the proposed method reliably obtains the absolute phase information.
We present a simple calibration method of the phase-based 3D imaging systems based on an uneven fringe
projection method. The relationship between absolute phase and depth is linear and independent of pixel position,
which can be represented by a polynomial function. By designing a plate having discrete markers with known
separate distance in between on the plate surface and projecting uneven fringe pattern onto it, one can calculate the
absolute phase of the centre on each marker. The 3D coordinates of all the markers can be obtained by a general
CCD camera calibration method. So coefficient set of the polynomial function are determined by using the obtained
absolute phase and depth of all the markers. The proposed method was applied to calibrate a phase-based 3D
imaging system. Experimental results and performance evaluation show that the proposed calibration method can
easily build up the accurate relationship between absolute phase and depth information data.
Phase-based 3-D fringe projection imaging systems have been widely studied because of the advantages of fullfield,
high accuracy, fast acquisition and automatic processing. The calibration of phase-based 3-D systems is an
important procedure, which builds up the relationship between the obtained absolute phase map and the depth
information. In this paper, a fast and flexible calibration method for phase-based 3-D imaging systems is presented
based on an uneven fringe projection method. The relationship between the measured phase and the object's depth
is linear and independent of pixel position, so it is possible to calibrate the 3-D imaging system by using discrete
markers (with known separation) on a white plate. Projecting uneven fringe pattern sets onto the plate can calculate
the absolute phase of each marker. At the same time, the depth of the markers can be obtained by general camera
calibration methods. Therefore, the linear relationship between the measured phase and the depth can be
determined. The proposed method was applied to calibrate an existing phase-based 3-D imaging system which
utilizes the uneven fringe projection technique. The entire calibration procedure does not require accurate
movement of a reference plane within the measurement volume. The calibrated system was evaluated by measuring
an accurately positioned white plate. Experimental results show that the proposed calibration method can easily
build up an accurate relationship between the absolute phase and the depth information.
In this paper, a method for designing a portable UV-Vis Spectrophotometer is introduced. A miniaturized dispersion
system is developed based on Hamamatsu array detector S3904 - 1024Q and flat field concave holographic grating. In
order to solve the contradiction between spectral width and energy-utilizing ratio of light source, multi-band optical
fibers are employed, which one side of the multi-bands optical fiber is arranged to be rectangle as incidence slit. The
touch screen is employed as input and output system of the spectrophotometer and the miniaturized fiber-optic UV - Vis
light source is employed as light source. The research and testresults of prototypes show that the new spectrophotometer
based on our new method is miniaturization in volume (190*170*100mm3), can realize multi-wavelength detection
on-line, is easily handled (touch screen control) and the performance accords with the Chinese National Standard.
Multi-junction solar cell (MJ) has been paid more attention for space and terrestrial concentrator system applications because of more efficiency has achieved. The spectral response (SR) of MJ is an important characteristic for technique optimization or performance evaluation. Measurement of SR of MJ cell is quite more difficult than that of single-junction solar cell (SJ) because a complicated light biasing and voltage biasing system is needed.
The object to be tested is GaInP/Ga(In)As/Ge triple-junction monolithic cells, and Ge bottom subcell with non-ideal properties would suffer from measurement error by improper voltage biasing. Since monolithic MJ cell without any middle taps, the internal characteristic is inaccessible, so the external biasing voltage usually obtained by estimating. It is well known that the characteristic of semi-conductor device has wide variance range, so significant deviation is often observed by a fixed estimating value. The paper proposes a method which could access the internal characteristic of MJ indirectly based on measuring other than estimating or mathematics model, and it has been proven by experiment with two SJ component cells, Ga(In)As cell and Ge cell.
With the development of modern medical research, people's understanding to thrombus and hemostasis is more and more profound. One of the remarkable characteristics is the rapid development of coagulometer and its widespread use for the examination of thrombus and hemostasis. After studying the present methods of cruor measurement, the paper introduces a cruor measurement method with double light beams based on Lambert-Beer Law. The point of the paper is the principle of cruor measurement and the method of data processing.
With the development of the research on life sciences and clinic medicine diagnose, the fluorescence microscope is requested to not only satisfy subjective observation, but also have computer external analysis. It also is requested to not only offer image conformation information, but also offer image spectrum information. The research of the system is brought forward for satisfying the questions. It found the solutions to that the traditional fluorescence microscope could not offer contiguous adjustable excitation spectrum, and that we could not get digitized fluorescence microscopic image information and spectrum information and so on. The paper detailedly specifies the pivotal technologies of the research of the continuous spectrum analytic system of micro-fluorescence image: the part of excitation lamp-house, the part of micro- fluorescence image acquisition and the part of computer control analysis.
This paper is centered on the development of reagent-free method based on Fourier transform mid infrared (FT-MIR), near infrared red (NIR) and Fourier transform (FT)-Raman spectroscopy. Suitable spectral wavenumber regions were selected for principal least square (PLS) regression and calibration models developed. In MIR, urine sample measured with Horizontal ATR, which is the accessory of Perkin-Elmer Spectrum GX Spectrometer, and the important range is 900-1800 cm-1. NIR spectra are obtained for each sample with 1mm pathlength. Absorption spectra of urine samples in 5000~4200cm-1 is used for PLS regression. The Raman spectra were recorded with a Bruker IFS 66 spectrometer with an FRA 106 FT-Raman accessory unit. The FT-Raman spectra of albumin power and albumin solution is recorded. The main noise is form water. The root mean square error of prediction (RMSEP) of glucose is 34.9 mg/dL(MIR), 31.56mg/dL(NIR) , and the RMSEP of albumin is 23.2mg/dL (MIR), 17.9mg/dL(NIR). Result indicated that FT-MIR and NIR spectroscopy could be used for rapid analysis of urine. FT-Raman spectroscopy could applied for compositional identification.
The technology of computer analysis for gel electrophoresis images is based on the computer image analysis and gel electrophoresis. Particle in complex mixture have different molecular weight and with different charge. Migration distances of sample zones are compared with the position of standards and the molecular size of unknowns is determined. By this way, biology particle and molecule with different compound can be separated from other. Digital camera can acquire image and process digital transact, then based on the digital image to realize automatic identification, sign, molecular weight calculate. For the convenient of observe and acquire, sample pre band on ethidium bromide stained agarose gels. The instrument is mainly made up of UV light source, digital camera and camera obscura etc. Formulas for calculate of protein's molecular weight and mobility in polyacrylamide gel is connected with standard curve and the relative mobility of band. After many experiments the conclusion can be deduced that the change of electrophoresis start point and front edge (m, n, r's value) will result in the change of K and b. Unknown samples' molecular weight only have relation with the standard sample's molecular weight and the value of r1, r2 and r3.
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