Traditional calibration methods for a Stokes ellipsometer will reduce the calibration accuracy of instrument matrix and effect the measuring accuracy of a polarization state, due to the polarization effect of incident light and the imperfect optical elements in a calibration unit. To measure precisely the instrument matrix of the Stokes ellipsometer, a calibration method was proposed based on the nonlinear least-square fitting method. By taking error sources mentioned above and instrument matrix together as unknown parameters, the function formula between detector intensity and unknown parameters was established based on the Mueller matrix theory. Then nonlinear least-square fitting method was used to fit the detecting intensity curves changed with the azimuth of calibration units and to calculate the instrument matrix of Stokes ellipsometer. The new method and traditional methods were used to calibrate the instrument matrix at 500-700 nm, and it is shown that the total Root Mean Square (RMS) of theStokes parameter by the proposed method is 1.6% in 500-600 nm, about 0.5% less than that of traditional methods. Moreover, when wavelength is larger than 600 nm, the RMS drops to 2.4%, but it still is far less than that of traditional methods. In conclusions, the method is easily feasible and is suitable for the calibration of instrument matrix for various Stokes ellipsometers.

In consideration of the drawbacks of mass-spectrometry in isotope analysis, a spectroscopy based on Degenerate Four-wave Mixing (DFWM) was proposed to analyze atomic isotopes and to overcome these limitations, like limited resolution, higher detection limits and complex sample preprocessing. Rubidium (Rb), cesium (Cs) and potassium (K) isotopes were selected as measured samples and an atomizer based on graphite oven was used to atomize these compounds into atomic steams. The analytic results show that the DFWM spectroscopy has a higher resolution and it can distinguish isotopes and hyperfine structures of the three elements clearly. The measured isotope abundance ratio of Rb isotope is (2.649±0.002), which is superior to the sensitivity of traditional mass spectroscopy. The detection limits of proposed method is as low as 5.4 fg/ml, 0.63 pg/mL and 0.09 fg/mL for Rb, Cs and K isotopes,respectively. Obtained results demonstrate that the spectroscopy based on DFWM has a higher resolution, lower detection limit and is more suitable for the isotope analysis as compared with the origional mass spectrometry.

On the basis of the asymmetric distortion from asphere measurement by a Computer-generated Hologram(CGH), three basic distortion models were analyzed, and an effective correction method for asymmetric distortion was proposed. By using a few fitted parameters, the method can correct the asymmetric distortion accurately, reduce data point pairs needed by distortion correction and can avoid over-fitting effect. Furthermore, the distortion of whole interferometric system was simulated, and its distortion was corrected by the proposed method. The simulating result shows that the relative residual of the correction is less than 0.2%. Finally, an off-axis CGH was designed and fabricated to verify the reliability of the correcting method and an asphere surface was tested with this CGH. Then, the correcting method mentioned above was used to correct the testing result, and the correcting result was taken to fabricate the asphere iteratively. The experiments show that the aspheric surface figure converges at 1.8 nm RMS (Root Mean Square) eventually. These results verify the reliability of the correction method.

To improve the efficiency and flexibility of femtosecond laser fabrication, a holographic femtosecond laser parallel fabrication system was built. The relationship between the uniformity and the spatial distribution of multi-foci generated by Computer-generated Hologram (CGH) was studied. Firstly, a Spatial Light Modulator (SLM) was introduced into the femtosecond laser fabrication system. Then, Gerchberg-Saxton(GS) algorithm was used to design three foci arrays of straight-line distribution and triangular distribution. Finally, the effects of holograms designed by foci arrays of straight-line distribution and triangular distribution on the uniformity were compared by numerical simulation and experiments. The results show that the foci array of straight-line distribution is not easy to obtain higher uniformity, and its three-foci U is only by 79%; however, that of the triangular distribution tends to achieve higher uniformity and its three-foci U is about 100%. The experiment shows that the three foci of triangular distribution can implement a high quality parallel processing and obtained hemispheric microstructures have microlens array functions .

By taking soil samples as targets, a small carbon chamber was used to perform the spatial confinement for high energy laser induced plasma to improve the quality of laser-induced breakdown spectroscopy. A high energy laser was used to ablate the soil samples, a spectral analysis system consisting of a modular multifunctional grating spectrometer and a CCD detector was adopted to record the spectral information, and the changes of the radiation intensities of laser-induced soil plasma with and without the small carbon chamber were studied. Then, the electron temperature and electron density of the plasma were measured by the spectroscopic methods to explain the mechanism of irradiation enhancement of the plasma. Experimental results show when the laser plasma is confined by the small carbon chamber , the spectral line intensities of the sample elements Mn, K, Fe and Ti increase about 90.77%, 101.71%, 104.27% and 60.77% than that without the small carbon chamber, and spectral signal-to-noise ratio raises around 54.29%, 55.30%, 59.37% and 38.80%, while the electron temperature and electron density of the plasma enhance about 1 684 K and 1.8×1016 cm-3, respectively. These results demonstrate that the spectral intensities and signal-to-noise ratio of the laser-induced plasma can be improved effectively by spatial confinement for the high energy laser induced plasma, which is an effective means for detecting the low-content elements in soil samples.

As the transmission properties of Frequency Selective Surfaces(FSS) will get worse because of the air gaps between FSS and original radome in the experimental stages, a novel snow loop element FSS was designed to reduce the effect of air gaps. The theoretical simulation was performed by using the mode matching method. For contrast, the best FSS structure designs of the novel snow loop element and Y loop element for the assumed qualification were chosen out respectively. The equivalent FSS sample plates were fabricated by using photolithographiy, and the transmission properties were tested in a microwave dark room to check the simulation results. Both the calculating and the testing results show that the novel element FSS meets the transmission request in a quite wide air gap range (190-6 500 μm), which is much better than the best Y loop design(320-1 900 μm). Advantages of this new type snow loop element FSS were briefly analyzed. It demonstrates that the snow loop FSS has very low sensitivity to the air gaps, which provides a new method for the FSS study in the experimental stages.

An economical type large-scale laser coordinate automatic measuring system based on a portable laser rangefinder and a biaxial-turning-table was presented to measure large work pieces, such as ship bodies in the fields. The measurement principle and the main components of the system were introduced. Under the control of a computer, this system could complete automatic scanning measurement without a cooperative target, and also could get the relative coordinate data to the system of the target. The effects of main errors of the system on the measurement results were analyzed, and some experiments were performed to extract and calculate the main errors of this system. Finally, the laser tracker was used to evaluate the measurement accuracy of the distance between two points and to measure a ship body model. From the measuring experiments, it points out that the measurement accuracy of the distance between two points is better than 1.73 mm in 10 meters, and that of the distance between two parallel planes of the ship body model is better than 1.5 mm. These results indicate that the system is suitable for ship body automatic measurement because of its simple construction, low cost, high precision and a higher measuring speed(1 point/s).

To obtain a smooth surface of etched-fiber core, a flow etching system was developed based on mass-transfer and dynamic response characteristics in silica optical fiber etching processes. The effects of fiber composition, etchant temperature and flow rate on the etching rate of fibers and the surface morphology of etched-fibers were investigated in the mass percent concentration of Hydrofluoric Acid (HFA) at 12.5%, respectively. The experimental and theoretical studies show that the etching rate and the surface roughness of the etched-fibers are controlled by the chemical reaction rate and mass transfer rate. The etching rate of fiber core is higher than that of fiber cladding because of the compositional difference between the fiber core and fiber cladding. In the static etching condition, the increase of the etching rate is nonlinear with temperature, and the etched-fiber gives a rough surface.Moreover,in the flow etching condition, the etching rate is improved and is linear with temperature, and the roughness of the etched-fiber core increases at first and then decreases with the increase of etchant flow rate. The results also show that the etched-fiber core with smooth surfaces can be repeatedly obtained with the etchant flow rate at 0.75 L/min.

As the spectral pathlength obtained by spectral subtraction approach with different flow blood volumes is uncertain in a near-infrared noninvasive biochemical analysis, it is difficult to obtain a high performance calibration model. Therefore, a pathlength correction space method was proposed to eliminate the uncertain and to improve the performance of calibration. Firstly, the principle of Net Analyte Signal (NAS) and how to obtain a correction space were introduced. Then, a new approach to get NAS was proposed using the pathlength correction space according to the features of spectral subtraction approach. Finally, by taking the intralipid with different glucose concentrations for example, the NAS of glucose was acquired by using the pathlength correction space and a calibration model was established. Compared with the Partial Least Square(PLS) model without pathlength correction space, the correlation coefficient has been improved from 0.978 1 to 0.997 7, the Root Mean Square Error of Calibration (RMSEC) from 77.52 mg/dL down to 25.02 mg/dL, and the Root Mean Square Error of Cross Validation (RMSECV) from 93.01 mg/dL down to 68.22 mg/dL. The analysis result verifies that the pathlength correction space can effectively restrain the influence of different pathlengths and the method can set the stage for the practical application of the spectral subtraction approach with different flow blood volumes.

A method to measure ice-water two-phase flow was proposed by using an Electrical Resistance Tomography(ERT). An ERT system was designed and the calculating method for phase fractions was explored based on imaging technology. Firstly, the principle of ERT system was introduced, and the design scheme for the ERT system with 16 electrodes was proposed, then a Linear Back Projection (LBP) image reconstructed algorithm were given. Furthermore, the analyzing methods for measured data of ERT system were presented and applied them to the identification of phase distribution and the estimation of phase fractions. Finally, several experiments were performed to verify the applied feasibility of the ERT system to ice-water two-phase flow measurement. The experimental results show that the ERT system can be used to obtain the positions of ice column within a tube in water and their movement sates in real time and can reflect the phase distribution of ice-water two-phase media intuitively. The relative sizes of the ice column can be obtained by the ERT system and the error of phase fractions are 6% and 2.8%, respectively. The research results prove that the ERT system can monitor the transportation process of ice-water two-phase flow on-line with higher measuring accuracy.

Because unstable transportation of the fluid in an open microchannel restrains the integration of sampling and detection for bioaerosols, this paper proposes an open microchannel covered with a hydrophobic mesh to transport water in stability. On the basis of theoretical calculation, it gives a estimation formula of fluid transportation characteristics for the open microchannel and analyzes experimentally the fluid transportation characteristics by taking the water as transported media. The results in analysis and experiments demonstrate that the stability is dependent on the mesh properties and flow velocity, and is sensitive to the geometric parameters and the surface properties of the microchannel. The more hydrophobic the mesh is and the smaller the mesh holes are, the higher the maximum allowable pressure in the microchannel is and thus the water transportation is more stable. For a Teflon-coated mesh with a hole size of 50 μm, the maximum allowable pressure is up to about 2 000 Pa. Furthermore, the maximum allowable flow velocity in the channel is determined by the channel geometric parameters and the maximum allowable pressure of the mesh film. The maximum allowable velocity decreases with the decreasing height and increasing length of the microchannel. For a hydrophobic channel, the capillary pressure originated from the surface tension deteriorates the stability of the water transportation, and the adverse effect is more significant in a smaller channel.

The evolution of dislocations in an austenitic region has a close relationship with the processing of precipitation during the alloy steel deformation. To verify the relevance of the refining structure of bainite and the pining dislocation networks of nano-size precipitation for Fe-40Ni alloy, the thermo-simulation test, metallographic analysis, quantitative measurement and Transmission Electron Microscope (TEM) technique were used to study the precipitation of deformated low carbon microalloyed steel in a relaxation processing at 850 ℃ and its influence on bainite formed during subsequent cooling. The experimental results demonstrate that the microstructures (mixed ultra-fine bainite and martensite) of the tested steel have been refined effectively during relaxation processing and it shows that the optimum refinement can be obtained by 60-200 s relaxation after being deformed. Meanwhile, the dislocations can be pinned by the strain-induced precipitation whose sizes are less than 10 nm. The experimental results obtained from the tested steel are in a good agreement with that of the Fe-40Ni alloy simulations.

On the basis of characteristics of high precision projection objectives, a kinematic mount apparatus was proposed. In order to evaluate the performance of the kinematic mount apparatus, the geometrical deformation and the optical surface figure reproducibility of a lens caused by the kinematic mount apparatus were investigated with Finite Element Method(FEM) and experiments. Firstly, the working principle of kinematic mount apparatus was introduced and the analysis method for surface deformation was also given. Then, surface deformations from the experiment and the finite element analysis were fitted with Zernike polynomials and obtained results by the two methods were compared for verifying the feasibility of the FEM. Furthermore, the optical surface deformation of the lens caused by the kinematic mount apparatus under the gravity was also explored. Finally, the reproducibility of optical surface figure of lens during a repeating assembly of the kinematic mount apparatus was also given with the experiment method. The experiment and FEM results indicate that RMS values caused by clamping force are 1.004 nm and 0.973 nm, respectively, and that induced both by clamping force and gravity are 2.538 nm. Moreover, the Power, Pre Trefoil and Sec Trefoil are the main aberrations of surface deformation, and the optical surface figure reproducibility of lens is 0.645 nm during the repeating assembly. These results mean that the kinematic mount apparatus can keep the optical surface figure in a good reproducibility.

To test the control performance of attitude control software in real time for a micro-nano satellite under hardware limited, a real-time testing system for the attitude control software of micro-nano satellite was established and the control software was tested with the proposed system. Based on the dynamics and kinematics of satellite attitude, the environment information of satellite trajectory, and the mathematical model of an attitude control algorithm, a flight imitation platform for the micro-nano satellite was developed on a PC. Then, the efficient communication link between on-board computer and PC was established by a Controller Area Network(CAN) and serial communication. The main program of the attitude control software was also modified as required. Finally, the real-time control performance of the attitude control software for on-board computer was tested with the real-time testing system. Experimental results indicate that the attitude control software can complete the initial control stage and enter the bias three-axis stabilization mode by 18 446 s after the separation of satellite and rocket, which achieves the stabilization control of micro-nano satellite attitude. In the bias three-axis stabilization mode, the minimum one-axis attitude accuracy and the angular velocity stability of the satellite are within ±1.86°and ±0.048(°)/s, respectively, which meets the requirements of attitude accuracy and converge time of the control mode.

Narrow band gap semiconductor materials were composited to a photoanode to improve its light response characteristics and the photoelectric conversion properties of dye-sensitized solar cells(DSSCs). The citric acid gel method was used to prepare the CoAl2O4 nanopowders and the X-ray diffraction spectra were utilized to analyze the effect of roasting temperature on crystal structures and particle sizes. Then, the surface morphology of CoAl2O4 was observed by transmission electron microcopy, the absorbances of CoAl2O4 nanopowders and CoAl2O4/TiO2 porous composite films were tested by UV-visible absorption spectroscopy and the band gaps of CoAl2O4 nanopowders were calculated. By using CoAl2O4/TiO2 composite films as the photoanode, the DSSC was prepared. The optical performance of the DSSC was tested by a solar simulator and a SourceMeter and the influence of doping CoAl2O4 on the photoelectric properties of a DSSC was investigated. The results show that the optimum roasting temperature of CoAl2O4 powders is 700 ℃; and its band gap energy is 1.69 eV, which means that it is a narrow band gap semiconductor material. Moreover, the performance of DSSC is the best and the conversion efficiency improves by 62% when the amount of CoAl2O4 powder is 1%(weight percentage). The stability of the CoAl2O4/TiO2 composite thin film cells is better than that of the pure TiO2 thin film cell. These results demondtrate that compositing CoAl2O4 to TiO2 can improve the conversion efficiencies of DSSCs.

An auto-focusing method used for the multi-spectral imagers was proposed based on differential projection. The method uses an image processing unit and auxiliary focusing equipment of sensors to implement the auto-focusing processes for different spectral bands separately and simultaneously. Firstly, the focusing window was delimited manually according to the observation needs or was searched automatically on the basis of the corresponding relations of differential projection and target edges. Then, the focusing window data of the image to be focused and calculated were projected in x-direction and y-direction, the 1st norm of the two projection arrays' first order differential values was derived and the mean of the two sets of 1st norm data was computed. Furthermore, the RMS of the two means was taken as the definition evaluation value of this image. Finally, combined with the classic mountain climb-searching method, the auto-focusing process was finished. Experimental results indicate that the auto-focusing method based on differential projection can be realized accurately, and it has the same effect with the classic Brenner, energy gradient and Roberts gradient algorithm, approximately. However, the running time of differential projection is only 0.67 times of Brenner, 0.33 times of Energy gradient, and 0.33 times of Roberts gradient. With the advantages of its strong single peak features, good unbiased characteristics, high sensitivity and excellent real-time, the method can meet the requirements of high-precision auto-focusing very well.

For the combining torsional buckling of small size Carbon Nanotubes (CNTs) in the multi-field coupling condition, a mechanical model was established in a couple field based on nonlocal theory and the combining torsional buckling behavior of the model was studied. Firstly, the constitutive relation was introduced under thermo-electro-mechanical loadings by using an elastic shell model of continuum mechanics. Then, the nonlocal elasticity theory was induced to discuss the scale effect of the small size carbon nanotubes, meanwhile, in consideration of the van der Waals forces and the effect of surrounded elastic medium, the generalized governing equation of buckling for CNTs was established in the multi-field coupling based on nonlocal theory. With applied torque and torsion-related axial load, as well as changed temperatures and voltage loads, the influences of different factors on the combined torsional buckling behaviors was calculated numerically. Finally,the conclusion demonstrates the response of the combined torsional buckling of small size CNTs in the multi-field coupling condition,and reveals the relation between combined torsional buckling of small size CNTs and each field. Moreover, it shows that the ratio of critical buckling load between nonlocal and local theories is always smaller than 1, which indicates that the torsional buckling of small size CNTs is overestimated in classical theory.

To improve the tracking accuracy of an electromechanical actuator servo system, the methods to identify and compensate the noninearities of friction and backlash were put forward. The mathematical models based on the LuGre friction and the hysteresis backlash were established for the electromechanical actuator servo system with position loop and speed loop controllers. According to the identified nonlinearity models, the friction was compensated though a feed-forward method, and the backlash was compensated simultaneously though an inverse model as well. The experiments indicate that the maximum position tracking error of system after compensation decreases from 0.166° to 0.096°, and the maximum speed tracking error decreases from 2.723 r/min to 0.393 r/min when the given signal is sine wave with an amplitude of 1° and a frequency of 2.5 Hz. It concluds that the friction and backlash models can be accurately obtained by the proposed identification methods, and the tracking accuracy of the electromechanical actuator servo system can be improved through nonlinearity compensation on the basis of the proposed models.

Co50 alloy coating and Co50 composite coatings doped with different mass fractiones of TiC were prepared by a 6 kW transverse-flow CO2 laser to improve the wear resistance of H13 die steel. The bonding characteristics, phase composition and wear behaviors of the coatings were investigated by X-ray diffractometry(XRD), Scanning Electron Microscopy(SEM) and high-temperature wear tester. The experimental results indicate that Co/TiC composite coatings with the content of TiC less than 20% (weight percentage) show good metallurgical bonding characteristics with the substrate surface. In addition, the micro-hardness of TiC/Co based coatings increases with the TiC content, but matrix phase composition of the composite coatings tends to be simple: Co+10%TiC coating consists of TiCo3, Cr2Ni3 and Cr-Ni-Fe-C phases, while Co+20%TiC coating is Cr2Ni3 and γ-Co, and Co+30%TiC coating mainly is composed of γ-Co solid solution. Co+20%TiC coating shows better wear behavior than Co50 coating, as well as has a more stable friction coefficient. Moreover, the high-temperature wear is mainly caused by oxidation wear and fatigue wear.These results demonstrate that Co+20%TiC composite coating has good comprehensive properties.

As slippage influences the tracking error of a telescope with friction drive, a way to detect and correct the slippage of friction drive was proposed for astronomical optical telescopes. A slippage dynamic detection system, a normal pressure active adjustment system, and a simulation and detection system of load fluctuation were established. The position of dynamic load was measured by a tape encoder and the position of active drive wheel was measured by a coaxial angle encoder. Then, the slippage was detected by transmission ratio. The Programming Multiple Axis Controller(PMAC) was used as a main control unit to control the normal pressure motor to adjust pressure and the control algorithm was also modified. By above way, enough friction drive force was obtained and the slippage was alleviated or eliminated. Experimental results indicate that the way can correct the slippage in time, improve the tracking precision of the optical astronomical telescopes and increase the stability of the drive system. In the most severe case, the friction drive system can resume the high accuracy tracking by detecting the slippage in 100 ms and completing the correction in 74.2 s. The method can be used for both single-point friction drive and multi-point friction drive and can solve the slippage caused by nonlinear disturbance.

Although megasonic cleaning can remove effectively nano particles in the Cu/low-k interconnection post-Chemical Mechanic Polishing (post-CMP) cleaning, the megasonic energy in cleaning may also cause extensive damage to microstructures. To predict the damage, the structural deformation and the stress distribution of Cu and low-k materials in megasonic cleaning were examined with Finite Element Analysis(FEA). Two-dimensional models were used in analysis of the stress-strain of a typical cell impacted by a caviation bubble in the circulate wiring pattern and all of the simulations were performed with ABAQUS. The results show that the maximum stress is concentrated in the binding area between Cu and low-k, which will result in the delamination of low-k materials. When the line width is 22 nm, the stress and deformation reach the largest values by 1 379 MPa and 3.074 nm respectively. When the line width is more than 22 nm, the max stress and max deformation decrease with increase of Cu line width. The increasing frequency will not change the stress distribution and displacement. The results are in agreement with the defect found in industrial applications.

To satisfy the requirement of an ultra-micro dispensing volume no more than 1 pL in micro-assembly and sealing engineering, an ultra-micro dispensing method applicable to both contact dispensing and non-contact dispensing was presented. In this method, a needle was moved through the capillary equipped with dispensing fluid and the droplet was adhered to its tip. When the needle tip approached to the target surface, the dispensing could be achieved due to the interfacial tension between the adhered droplet and the target surface. The dispensing volume could be easily controlled by matching the parameters of dispensing process. This method is suitable for any viscosity dispensing fluid ranging from 1 cP to 3.5×105 cP, and can dispense for spatial arbitrary directions. Based on an ultra-micro dispensing experiment platform built in this paper, the influences of needle diameter and gap (the distance between needle tip and target surface) on the size of dispensing spot were investigated. According to the studies, proper needle diameters, gaps, inner diameters of capillary and dispensing velocity were chosen, the ultra-micro dispensing with the volume of 40 fL, 170 fL and 180 fL was achieved when the fluid viscosity was 971 cP and the dispensing spot diameter was 243.9 μm, as well when the viscosity was up to 3×104 cP. The experimental results verify that the proposed method is feasible.

The flowing state of liquid medium for the rotor at high-speed rotation in a suspended rotor gyroscope was explored. The Reynolds stress model of hydromechanics was adopted to simulate the closed flow field between the rotor and the stator, and the Micro Particle Image Velocimetry (Micro PIV) technology was used to observe the motion of flow field and to measure the speed of flowing field. The simulation results indicate that the upper and lower surfaces of the rotor form different types of secondary flows with sidewall surfaces, and this phenomenon is enhanced with the increase of velocity and spatial dimensions. When the speed of the rotor increases to 7 500 r/min, the speed of secondary flow reaches 0.3 m/s, which means that reducing space dimensions helps to improve the motion stability of the rotor. The experiment proves that Micro PIV technology is capable of accurate observation of the flow velocity with the rotor speed at 0-1 000 r/min, and can meet the requirements of non-contact test of the flow field.

The effect of Pulse Density Force Feedback (PDFF) on the performance of a micro-machined gyroscope was investigated and a closed-loop circuit for the micro-machined gyroscope was designed based on a mechanical and electrical ∑Δ modulator. Firstly, from the equivalent forms of a sense mode for the micro-machined gyroscope, the effect principle of PDFF on the performance of sense mode was analyzed and it was divided into two parts: negative stiffness and gain effects. The analysis shows that the negative stiffness is independent on the input of angular rate. Then, the relationship between pulse density and input angular rate, and that between input range and high level feedback pulse were built based on the theory of closed-loop detection. Finally, the circuit parameters were calculated by using the range design index and the actual parameters of gyroscope, then these parameters were simulated in Simulink. Simulation result shows that the parameters satisfy the design objective, and the nonlinearities between average pulse density and angular rate are 3.6×10-6, 3.07% and 5.12%, respectively, when the quadrature error equivalent input angular rates are 0(°)/s, 30(°)/s and 50(°)/s. Two gyro sample I and II with the quadrature error equivalent input angular rates of 30.4(°) /s and 47.3(°)/s were tested, and the experiment results show that the effect of PDFF on the negative stiffness doesn′t change with the pulse density; and the nonlinearities between the average pulse density and angular velocity are 2.9% and 4.8%, respectively. The experimental and simulation results get a better match.

As traditional Adaptive Direction Lifting based-Discrete Wavelet Transform(ADL-DWT) has higher computational complexity in the compression of high-resolution remote sensing images, this paper proposes a new lifting wavelet transform scheme based on Direction Prediction called DP-LWT to implement the fast and efficient compression of high-resolution remote sensing images. The new algorithm first divides a high-resolution remote sensing image into a number of non-overlapping sub-blocks. Then, the gradient operator is used to predict the best lifting direction of every sub-block in the remote sensing image quickly, and completes the direction lifting wavelet transform by the interpolation along the best lifting direction. Finally, the remote sensing image is coded by Set Partitioned in Hierarchical Tree(SPIHT). The experimental results show that the new algorithm effectively weakens the high-frequency coefficients on the non-horizontal and non-vertical directions of every image subband. Compared with the traditional ADL, the DP-LWT can effectively reduce the time computational complexity of directional prediction in lifting wavelet transform, and keeps the Peak Signal to Noise Ratio (PSNR) of the reconstructed high-resolution remote sensing image to be the same as that of the ADL basically.

A new algorithm based on Shape Context(SC) and Principal Component Analysis(PCA)called PCA-SC was proposed to improve the matching efficiency and anti-noise performance in shape matching and object recognition. The algorithm establishes a covariance matrix based on the feature matrix obtained by the SC, then reduces its dimensions according to the size of eigen value and forms a new feature matrix to implement the shape matching and object recognition. The proposed algorithm can not only remove noise interference and improve the recognition accuracy, but also can enhance the matching efficiency for real-time application. The experimental results of MNIST database indicate that the PCA-SC algorithm outperforms previous SC algorithm, and its recognition speed is doubled that of SC and the accuracy reaches to 96.15% increased by 0.5%. Furthermore, the anti-noise performance becomes stronger. Therefore, this algorithm shows better performance for shape matching and object recognition in efficiency, accuracy and anti-noise.

To improve the security of watermark, a three-dimensional (3D) object was employed as the watermark to embed in a host, and a new technique of multiple watermark embedding was proposed based on Computer-generated Hologram (CGH). The tomography was used to obtain the Fresnel hologram of the 3D object. Then, the Arnold transformation was used to encrypt the hologram by scrambling the image, and the scrambled image was taken as the watermark to be embedded in. Furthermore, the Discrete Cosine Transformation (DCT) was chosen as the embedding and extracting algorithm and the Arnold transformation times and the different diffraction distances of every layer were regarded as encryption keys. Numerical and optical experimental results show when the keys are all correct, the reconstructed result of hologram extracted from the watermark is accord with that direct reconstructed hologram, and can display different information at different layers of the 3D object; otherwise, no useful information could be distinguished when the keys are all incorrect. These results prove the effectiveness and security of proposed method, and show that the method can allow the watermark to be three-dimensional and multiplicity.

To discriminate the ripeness of cotton quickly and accurately, 15 shape structure features were extracted from cotton images and the execute efficiencies and classification accuracy of their feature subset selection algorithms such as Wrapper-based Exhaustive searching and Wrapper-based stopping(WE-W) and Filter-based Heuristic searching and Wrapper-based stopping(FH-W) were compared by using 10-fold cross-validation. By taking the error rate of a Bayes classifier on validation set (WE-W) and the class-separability measuring value on a training set (FH-W)as assessing functions, the optimal l (l=1,2,3, …, 15) feature subset was searched by using exhaustive (WE-W) and heuristic (FH-W) strategies on the training set, which stops at the minimum error rate of Bayes-classifier on the validation set(WE-W and FH-W). Experimental results show that the average classification rates of WE-W and FH-W algorithms on the prediction set are 85.39% (WE-W) and 85.28% (FH-W) at l=3, respectively. It concludes that the FH-W algorithm can be a reference in practice for its higher execute efficiency and good classification accuracy.

As the Center-Symmetric Local Binary Pattern(CS-LBP) for the iris recognition has a higher feature dimension and is sensitive to noises, an effective improved method based on Statistical Characteristics Center-symmetric Local Binary Pattern(SCCS-LBP) was proposed. Firstly, a normalized iris image was encoded by CS-LBP according to the distribution characteristics of iris texture, and the statistical characteristics of the encoded image was computed to reduce the feature dimension. Then, the binary feature image of iris was extracted based on statistical results. Finally, the Hamming distance matching vector was obtained to implement the iris recognition. This method was used to CASIA1.0,CASIA2.0,CASIA3.0-Interval and MMU1 database, the results show that the highest correct recognition rates reach respectively 99.955%, 99.848%,99.989%, and 99.916%. The experimental results demonstrate that this method effectively utilizes the iris texture distribution characteristics, and have the advantages of lower dimension, higher recognition rate and better robustness as compared with LBP and CS-LBP methods.

On the basis of prostate tumor diagnosis by nuclear Magnetic Resonance Imaging(MRI), a two-stage ensemble Support Vector Machine(SVM) method were proposed to realize the prostate tumor aided diagnosis. Firstly, the statistical features, invariant moment features and the texture feature of the Area of Interest( ROI )for the prostate in a MRI image were extracted. Then, SVM parameters were disturbed by using different kernel functions in different feature spaces, and the first ensemble was carried out by relative majority voting. Furthermore, the results of first ensemble were integrated again by the relative majority voting. Finally, MRI images of prostate patients were regarded as original data, and two-stage ensemble SVM were utilized to aid tumor diagnosis. Experiment results show that the classification accuracy from the first ensemble has improved by 26.67% as compared with that of single-stage SVM and that from the second ensemble has improved 3.33% than that of the first ensemble. These results illustrate that the proposed algorithm can improve the recognition accuracy of prostate tumor effectively.

Many traditional feature point algorithms can not handle more complex nonlinear brightness changes because the gray between multi-source remote sensing images is nonlinear changes. To cover the shortage, a Scale Invariant Feature Transform(SIFT) feature matching algorithm of multi-source remote sensing images was proposed. First, the approximate linear gray value between multi-source remote sensing images was achieved through linear fitting of the bands of the images. Then, an improved SIFT algorithm was adopted to match the fitted remote sensing images. Finally, the random sample Consensus algorithm was used to remove the false matching point pairs. In comparison with other feature matching algorithms (SIFT, Gradient Location Orientation Hologram(GLOH), RS-SIFT). The experimental results show that the feature matching rate increases by about 4% between ETM+ panchromatic and multispectral images and the number of correct matches of key points increases by about 8 point pairs between CBERS-02B and HJ-1B images. It concludes that the proposed method significantly outperforms many state-of-the-art methods under multi-source remote sensing images.

The defocusing of imaging plane for a space camera in severe space environments will effect the imaging quality. It is necessary to compensate the defocusing effectively for the space camera to improve the adaptabilities and to get a high quality image. A novel focusing system was designed for a multispectral camera with off-axis Three Mirror Anastigmat(TMA) system. Firstly, the focusing method was chosen, and the principle of focusing was described by analyzing the characteristics of the off-axis TMA system and the CCD focal plane. Then, the focusing system was introduced in detail, including the working condition of a focusing controller, the way to calculate the torque of a stepper motor,and the design parameters of focusing mechanism and the position sensor. Furthermore, the correlation between the focusing accuracy and focusing mechanism, sensor resolution was deduced. Finally, the relative curve of CCD position with an encoder was obtained in the focusing range by the proposed focusing system. Experimental result shows that the focusing accuracy in closed-loop control is ±3.11 μm (3σ). It can satisfy the system requirements of ±10 μm.

In combination of reference standard sampling and calibration methods, a multi-target area calibration linear correction algorithm was proposed to correct the nonuniformity of fluorescence detection of microfluidic Polymerase Chain Reaction(PCR) system and to improve the performance of the system. The fluorescein sodium solution with similar spectral characteristics to PCR fluorescence marker SYBR Green was used as the test sample, and the emission fluorescence intensities of eleven uniformity sodium fluorescein solutions with different concentrations were measured. The linear relationship between fluorescence intensities and fluorescein sodium concentrations was analyzed and the correction coefficient matrix in each imaging target area on a CCD was calculated by a two-point linear correction algorithm. The results after correction show that the imaging uniformities in three different concentrations of sodium fluorescein solutions are improved respectively from 71.28%, 72.01%, 70.73% to 77.49%, 80.07%, 90.64%. The relative standard deviations of Ct value for the same concentration DNA template are reduced respectively from 4.38%, 1.94%, 3.31% to 2.44%, 0.79%, 1.31%. These results indicate that the proposed nonuniformity correction algorithm significantly improves the accuracy of microfluidic real-time PCR.

According to the image blurs caused by platform vibration in a staring imaging system in the geostationary orbit, a vibration suppression method based on multiple integration was proposed to eliminate the motion blur degradation .A 1D vibration platform with a high-speed CMOS image capturing system was built to collect image sequences with different vibration frequencies under different exposure conditions. Next a phase correlation method based on the energy area center was proposed to calculate the relative drift of each image in sub-pixels. Then, The sub-pixel displacements between the different frames estimated by image registration algorithm were compared with the motion data measured by the displacement sensor ,which proved that the algorithm precision was better than 0.1 pixels. Furthermore, several sharpest short-exposure frames were chosen for sub-pixel image fusion. Compared with long-exposure images, the motion blur in the fusion image has been weakened. It has proved that the method of multiple integration and sub-pixel image fusion is suitable for the vibration suppression of staring imaging systems in the geostationary orbit.

A remote sensing image JPEG2000 compression scheme with precise quality control was proposed. According to the perfect reconstruction of wavelet filter banks and the statistical independence of subband coefficient quantization error, a mathematical expression formula was established to describe the relation between the peak signal to noise ratio and the wavelet coefficient quantization error. Based on the traditional JPEG2000 rate distortion model, a distortion-based rate minimization model was constructed and optimization truncation coding stream to obtain a desired target image compression quality was given. An experiment on standard test images and satellite remote sensing image was performed and obtained results were compared with that of the conventional rate-based distortion minimization JPEG2000 encoding. Results indicate that the new method has the same coding structure and computing complexity, and it can accurately control the compression image quality with an average control precision less than 1%. In addition, this proposed method has higher global compression im-age peak signal to noise ratio at the same total coding rate for sequence remote sensing images.

To suppress the mutual affects among different structure features of retinal and improve the detection precision of retinal microaneurysms, a microaneurysm extraction algorithm by fusing relationship among features was proposed. Firstly, the mean filter was applied to a retinal grayscale image, both the circular border and optic disc were detected, and the optic disc mask was created. Then, the green component of the retinal image was equalized with an adaptive histogram and Canny method was used to extract the edges before removing the image circular border and to fill the enclosed small area objects. Finally, with consideration of the relationship among different features, larger area objects were removed and an ‘AND’ logic was used to remove the retinal exudates, blood vessels as well as optic disc to obtain the retinal microaneurysm image. Experimental results indicate that the proposed method can effectively extract the microaneurysms in the retinal fundus image, and their sensitivity, specificity, positive predictive value and accuracy are 94.81%, 96.04%, 91.64 % and 95.66%, respectively. It can satisfy the clinical application requirements for strong stabilization and higher precision.

The error of line transfer frequency from Time Delay Integration(TDI)CCD has strong influence on dynamic Modulation Transform Function(MTF) and it is stronger when the integral grade is higher.Therefore,this paper develops an accurate mathematical model for dynamic MTF and line transfer period error rate was developed. Firstly, a typical line transfer timing of TDICCD was introduced and the window functions of one integral grade and multiple integral grade were derived. On these bases, the relationship between line transfer period error rate and dynamic MTF for this timing was established by Fourier transform of the window functions and a nonlinear parameter was derived in the function which is none in the traditional one. Then, simulations and experiments were performed, which indicate that when ΔT/T=0, the dynamic MTF value for this timing is 0.632 5 times of static MTF with the number of phases b=4. It also indicates that there are obvious differences between dynamic MTF curves from proposed method and traditional method. Finally according to the requirement of the index, the maximum line transfer period error rates with different integral grades are given, which ensures that the decline of the dynamic MTF is less than 5%.

A lossless compression scheme consisting of a linear prediction and multiband lookup tables was proposed to compress the airborne hyperspectral imagery efficiently. Firstly, based on the Yule-Walker equation, a linear prediction model whose equation coefficient matrix is a non-Toeplitz type covariance matrix and it should be solved by an extension form of Levinson algorithm was established by exploiting the strong correlation of spectral bands of hyperspectral imagery. Then, a multiband lookup table algorithm was adopted to refine the prediction result based on the calibrated hyperspectral imagery containing a sparse histogram induced by calibration techniques. However, for the uncalibrated imagery, the multiband lookup tables could be neglected. Finally, the prediction residuals were sent to the entropy encoder. In the experiment, the Adaptive Arithmetic Code and Golomb-Rice Code were both tested as the entropy encoder. The experimental results show that the proposed scheme has a higher compression ratio and the compression effect is better than that of the standard from Consultative Committee for Space Data System(CCSDS).