Chinese Version Light学术出版中心
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Issue 9 ， 2008
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Design on support for primary mirror of space remote sensing camera
Abstract：In order to reduces outside loads’ influence on surface precision of primary mirror in space remote sensing camera, the design of adopting diverse flexible support structures which restrict primary mirror’s freedom of motion independently is brought forward. By adopting CAD engineering analytical software, dynamic and static rigidities as well as thermal characteristics of primary mirror system are analyzed emulationally. Based on this foundation, structural parameters of flexible support in primary mirror system are amended. Under precondition of ensuring support rigidity, the influence on surface precision of primary mirror due to gravity、assemblage stress and temperature diversification is reduced, and endurance of impact and libration is ensured during the launch. Detecting results show that the surface precision of primary mirror reaches PV:λ/4 and RMS:λ/50，which can meet the special requirements for the primary mirror of space remote sensing camera.Keywords：Space remote sensing camera;primary mirro;flexible support;lightweight- 70
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Published：2020-08-12 -
Design of a digital retina camera based on the eye model
Abstract：A portable digital retina camera in 30 field of view without mydriatic is designed based on Gullstrand-Le Grand eye model. After the comprehensive consideration of both the human eye and the camera, this design realizes the highly clear image with 2 mega pixels in all fields of view. And an eye model is used in this design to diminish the chromatic aberration brought by the human eyes themselves, so that the camera could use in the visible band. Meanwhile, in case of the stray lights caused by the cornea, the illuminating system with an annular stop and coaxial illumination is specially designed. The result shows that the resolution of this system is 120lp/mm, the field curve value is less than 0.86mm and the distortion value is only 7.2%, and this camera has strong abilities for accommodation, which could adapt the different eyes from -10D to 7D.Keywords：optical design;retina camera;eye model- 45
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Published：2020-08-12 -
Research on the radiometric calibration of the ultraviolet ICCD detector
Abstract：The radiometric calibration technology for ultraviolet intensifier CCD (UV-ICCD) detector is a new researching direction. It is necessary to study on the technology of UV-ICCD calibration to sure the test results’ accuracy and reliability. The purpose of the radiometric calibration for UV-ICCD is to build the relationship between the input irradiance and the digital output. The theory of radiometric calibration was derived. The radiometric calibration of the UV-ICCD was implemented in the laboratory. The calibration method is based on spectral irradiance standard deuterium lamp. Uncertainty of the deuterium lamp calibrated by NIST is 5%. The response of the UV-ICCD was tested under fixed MCP gain and fixed integration time. The relationship of the response with the MCP gain was studied. The preliminary analysis of calibration data shows that response of the UV-ICCD is linear and the MCP gain is in positive proportion to the average grey value of image. At last the uncertainty which influences the results of calibration was analyzed. The analysis of the uncertainty shows that the measurement accuracy is 7.94% and meets the requirement.Keywords：radiometric calibration;UV-ICCD detector;standard deuterium lamp- 52
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Published：2020-08-12 -
Location Error Analysis of Deformable Aspheric Polishing Lap Based on PZT Actuator
Abstract：Abstract: In aspheric mirror polishing progress, the deformable polishing lap can change the lap surface to fit the surface of aspheric optical mirror. A novel method of designing deformable polishing lap is brought forward by using PZT actuator. It consists of an aluminum disk which can change surface profile continuously under the control of PZT actuators. When the deformable aspherical polishing lap moves on the surface of aspherical mirror, the needed deformation of each PZT actuator is calculated at any location. After each PZT actuator deforming, the surface profile of deformable aspherical polishing lap is changed to an off-axis surface of aspheric optical mirror at that location. Location error will lead the deformation error of each PZT actuator and surface profile error of lap. In this article, location error is analyzed and calculated. The result shows that the location error should be controlled in less than ±0.5mm.Keywords：Aspherical Mirror;Deformable Aspherical Polishing Lap;Location Error Analysis- 96
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Published：2020-08-12 -
Optical constants determination of aluminum based on combined optimal algorism
Abstract：Objective：We propose an ex-situ method to determine the optical constants of aluminum thin films precisely. Comparing to the custom in-situ method, our method doesn’t need the complex optical measurement apparatus attached to vacuum chamber and can be performed simply and fast. Method：Using multi-wavelength fitting method, we fit the ellipsometric and photometric spectra with a combined optimal algorism of genetic and least square. The oxide layer formed on the aluminum in air is included in the fitting process. Result：The optical constants in the UV to visible range are obtained by this method within an error of 0.5%. Conclusion：With these data known, we design and deposit an UV induced transmission filter of one cavity. The tested transmission spectra are well consistent with those designed with a peak transmittance error of 1% at 265nm.- 53
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Published：2020-08-12 -
The Tracking and Guiding Method for Full Solar Disk Image Using Large CCD-Array
Abstract：This paper introduces a new auto-tracking and guiding system, which is based on mass-center algorithm and large CCD-Array with Full Solar Disk Image. It uses an Embedded System with high speed processing ability to compute and process mass-center data and all CCD image is dealed with binarization process. Compared with the previous one, the new system can largely reduce the cost and complexity and it enhances the accuracy of the tracking system and reduces the dependency of weather condition. It also constitutes a high-precision closed-loop tracking system. According to the analysis of the experimental data, the new auto-tracking and guiding system achieves the precision of during one hour observation. This system is also a concept experiment for Space Solar Telescope (SST).Keywords：solar telescope;auto-tracking;CCD guiding- 47
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Published：2020-08-12 -
Effect of bar’s non-luminescence on beam properties of laser diode arrays
Abstract：Based on far-field bi-peak structure of emitter, a far-field expression model of laser diode arrays(LDA) was proposed. Bar’s non-luminescence was ubiquitous when LDA was working. On the base of theoretical model and measured data, effects of bar’s non-luminescence on beam properties of LDA were studied. The results showed that non-luminescence of some bar or several bars could not change the far-field bi-peak of LDA exceed to some distance, but other properties such as peak intensity and position of peak intensity and intensity on center axis were effected. Power of LDA was in inverse proportion to numbers of non-luminescent bars and was not changed by position variety of non-luminescent bars. The work was useful for LDA’s use, especially for the design of the beam-shaping system of LDA.Keywords：LDA;bar;Intensity distribution;Power- 42
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Published：2020-08-12 -
Preliminary study of SiC:H surface-modified coatings with end-hall ion source assisted
Abstract：A new method for RB SiC (Reaction Bonded Silicon Carbide) surface modification is reported in this paper. Silicon is evaporated by E-gun, End-Hall ion source is imposed to ionize methane gas as a reactive gas, and it also assists coating formation to improve optical and mechanical quality, SiC:H coatings for modification are fabricated on RB SiC substrate. XRD (X-ray Diffraction) result shows all prepared coatings under the same condition areαphase. Hardness and elastic modulus are in the range of 9.781 GPa-13.087 GPa and 89.344 GPa-123.413 GPa, respectively. After surface-modification polishing and coating silver, reflectance is close to fine polished Zerodur glass coating with silver. Adhesion tests indicate the fabricated coatings adhere to the substrate firmly. Temperature impact experiments are performed through liquid nitrogen and boiling water for 5 cycles, no fall-off and cracks are observed.Keywords：Silicon Carbide;End-Hall ion source;Ion assisted;Hardness and elastic modulus- 34
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Published：2020-08-12 -
OCDMA Encoder/Decoder Based on Phase Shifted Superstructure Fiber Bragg Grating and there Correlation Property
Abstract：Recently optical code division multiple access (OCDMA) encoder/decoder based on phase shifted superstructure fiber Bragg grating (SSFBG) have attracted more attention because of SSFBG can generate long optical codes. The correlation property is fatal to the performance of OCDMA encoder/decoder. To evaluate the practical value of this kind of encoder/decoder the structure and bipolar encoding/decoding principle for OCDMA system based on phase shifted SSFBG are studied. The correlation property is simulated using transmission matrix method. The correlation property versus Bragg wavelength deviation between encoder and decoder because of the deviation of grating period is derived theoretically. Results indicate that the ratio of auto-correlation and cross-correlation is improved with the code length is increased, but the correlation property is more sensitive to the deviation of Bragg wavelength between encoder and decoder with the code length is increased while holding the chip pulse width. To obtain good correlation property the deviation of Bragg wavelength between encoder and decoder using Gold sequences with length 31 and chip duration of 6 ps must less than 0.02 nm. A code can be used with different Bragg wavelengths to implement hybrid wavelength division multiple (WDM) OCDMA system.Keywords：optical communication;Optical code division multiple access;Superstructure fiber Bragg grating;Correlation property- 48
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Published：2020-08-12 -
Laser and water-jet fiber coupling technology for water-jet guided laser micromachining
Abstract：In order to guarantee the coupling effect of focused laser and water-jet fiber, accurate coupling alignment system was set up, special coupling alignment method was put forward, special coupling unit was designed. Before laser arriving at water-jet fiber, it passes through air, glasses and water, so based on calculating result, a special adjustment method was used to determine the distance between the focus lens and the nozzle hole. The max angle of incidence of laser was researched for full reflection. After fluid simulation, a coupling unit was designed. It makes the fluid field in the chamber symmetry and can form high quality water-jet fiber which diameter is 0.12mm. The attenuation of laser energy in water-jet fiber was investigated. Applying appropriate laser wavelength, pulse energy and filtered and deionized water, energy attenuation in fiber was reduced. Experimental results indicate that: 100mm long water-jet fiber could be formed; 0.12mm wide slot can be cut in 0.2mm thick Si wafer at the speed of 2mm/s, nearly no crack, no heat affected zone was formed. Applying this coupling technology, perfect water-jet guided laser micromachining can be achieved.- 64
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Published：2020-08-12 -
Design of area-CCD KAI-1010M driver system with high speed
Abstract：The driver system of CCD is one of the key parts of a digital camera, which is related to camera’s technical parameters. After the inner structure and driver timing of a interline area-CCD KAI-1010M being introduced briefly, a CCD driver circuit which is used in the digital space survey camera, is designed with cheap products in a new way, the high speed and low cost is achieved in the same time. To resolve the technical difficulties, the pulse width modulation technology ,which is usually used in the power supply and motor control, is introduced into the CCD driver circuit and a ultra-high speed operational amplifier is adopted to reduce the high speed negative signal’s rise and fall time。The results show that the CCD driver system can output two groups of CCD signals simultaneously in data output speed of 15 frame/s . The driver system can meet the need of the camera system because of its good function and low cost. If improved, the CCD driver system can output two groups of CCD signals in data output speed of 27 frame/s.- 48
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Published：2020-08-12 -
The study of TDI pattern for interline transfer progressive scan CCD
Abstract：For the lower quantum efficiency and fill factor of interline transfer progressive scan CCD, which were applied in motion imaging area and lower exposure, will result in bad quality and lower signal and noise of image. The authors given a TDI pattern of this kind of CCD to overcome the default of it and designed a test system to realize it and obtain a satisfying result.Keywords：Interline transfer;CCD;TDI;quantum efficiency;motion imaging.- 64
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Published：2020-08-12 -
Research on Self-testing Method of Spatial Camera Controller Based on Mixed Language Programming
Abstract：A self-testing method of Digital Signal Processor（DSP） spatial camera controller based on mixed language programming is advanced. With this method the difficult problem of changing variables location in RAM according to self-testing results under mixed language programming is solved by modification of Runtime-Support Library. In this way it is easier to realize the complex algorithm of matching Linear Charge Coupled Device (CCD) camera’s row period to image motion in DSP spatial camera controller. In addition codes are more maintainable and transplantable. Problems in realization of self-testing arithmetic on DSP repertoire, Read Only Memory（ROM）, Random Access Memory（RAM） and other peripherals are analyzed and solved. An improved peak value test algorithm of RAM is put forward, which has higher test efficiency. As it is difficult to test self-testing algorithm itself without harming hardware, methods to validate self-testing algorithm are presented. DSP repertoire and RAM self-testing algorithms are tested with the use of emulator. Results of validation experiments and practical application effects in engineering prove that the self-testing algorithm is practical and valid.Keywords：spatial camera;camera controller;self-testing;DSP;self-testing- 44
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Published：2020-08-12 -
Design, manufacturing and assembly for mirror lens of a mapping camera
Abstract：Mirror lens of mapping camera is the important component, which can guarantee mapping camera to fulfill the mapping task with high precision. It’s performance will effect directly the imaging quality of the mapping camera. In order to gain the mapping camera with high imaging quality, the design of mirror lens is issued from the choice of materials, the decision of structure, the analysis of performance and so on. By compared, ZTC4 is selected as the material for mirror lens finally, and combination format is adopted that components with mirrors are assembled in the thin shell with stiffeners. Optical-mechanical structure with good overall performance is obtained though the static and dynamic mechanical analysis by PATRAN/NASTRAN. The geometric tolerance requirements are given, the processing methods of thin shell are developed, and the assembly process of one component and main mirrors lens is discussed.Keywords：mirror lens;design;manufacturing;Assembly- 74
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Published：2020-08-12 -
Research on On-board Embedded Software Testing Process Model
Abstract：Compared with ordinary software, the on-board embedded software has more requirements of software reliability. The software testing process model is a necessary means of improving software reliability. And it can guide us to test software in a scientific process and method. Therefore, in view of the features of on-board embedded software, this paper proposes an on-board embedded software testing process model - Butterfly model which is based on W model and X model. This new model not only reflects the test for entire development activities, but also supports iteration and alteration. It is especially suitable for the characteristic that on-board embedded software development process need multiple cycles. This study provides strong supports for effectively developing on-board embedded software and ensuring higher reliability requirements.Keywords：On-board embedded software;Software testing process model;W model;X model;Butterfly model- 84
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Published：2020-08-12 -
EUV Monochromator Wavelength Calibration
Abstract：This paper presents a new calibration method of EUV monochromator, that is, measuring line spectrum of 30.38nm and 58.43nm with the standard He hollow cathode source and the reflectivity peak of calibrated Mo/Si multilayer mirror which center position of wavelength is 13.90nm , then the wavelength of Mcpherson247 are determined, and setting a corresponding sign on the track of the monochromator with each standard point which we just calibrate in this experiment and make a curve with two-order parabolic equation by Origin software. When measuring the reflectivity of multilayer mirror by using a soft X-ray reflectometer with laser-produced plasma source, the analyses of calibration results indicate the accuracy is 0.08nm, and the repeatability is ±0.04nm in 1nm ～120nm wavelength band .Keywords：EUV monochromator;calibration;multilayer mirror;accuracy;repeatability- 41
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Published：2020-08-12 -
The Reflectivity Measurement of normal- incidence Mo/Si Multilayer mirrors in 13.9nm and 19.6nm
Abstract：Mo/Si multilayer mirrors were designed after theoretical simulation, whose central wavelength were 13.9nm Ni-like Ag and 19.6nm Ne-like Ge x-ray laser respectively. The reflectivity measuring set-up was composed of Mcpherson 247 monochromator and a small reflectometer. The Extreme Ultraviolet（EUV）source was copper-target Laser Produced Plasmas(LPP) source. The result showed that the central wavelength of Mo/Si multilayer mirrors were 13.91nm and 19.60nm respectively, the corresponding reflectivity were around 41.9% and 22.6%, and the related FWHM were 0.56nm and 1.70nm, the central wavelength and FWHM agreed with theoretical value basically. In order to study the Mo/Si multilayer performance, the measurement of surface roughness was carried out using WYKO, the surface roughness were 0.52nm for 13.9nm and 0.55nm for 19.6nm.Keywords：EUV;Mo/Si multilayer;reflectivity;surface roughness- 43
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Published：2020-08-12 -
The resolution test of the EUT
Abstract：We need to test the imaging performance of the EUT after finishing the alignment of it. The method is placing the resolution test-target on the focal point of the collimator and illuminating the target by visible light. Then the visible light is becoming parallel light go through the EUT and imaging at focal plane on the CCD. By analysis the image we can calculate the resolution of the telescope. The test result indicated that the angular resolution of the EUT is 1.22″ (λ=570nm) which is very close to the resolution limit (1.20″). After the computation we conclude that the operation wavelength resolution is 0.32″, under our design request.- 41
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Published：2020-08-12 -
The research of original position optic measuring technique based on virtual Lock-in
Abstract：This paper describes the build of a original position optic measuring system with high precision and wide scanning wavelength, which can measure feeble signal accurately buried in noise, based on virtual Lock-in technique. In this paper, we firstly introduce the aim, the structure, and the measuring principle of this system. Then we emphatically describe how to use the G language Labview to write a program to implement the virtual Lock-in technique, and how apply it in our system. This technique not only reduce the cost, but also simplify the structure of the system. After that we measured the distribution of lamp’ intensity between 200nm-2500nm; and measuring the repetition of wave band 200-860nm and wave band 860-2500nm.Finally we measure the transparence of a quartz glass, and compare with the measuring result of lambda950,the mean error is 0.95%. The results of experiment indicate that, this original position measuring system that use the virtual Lock-in technique to deal with the data, can measure well and truly, by restraining the noise brought by interferential light and electronic equipment. It is competent for original position measurement for specimens′optical character.Keywords：original position optic measuring;Lock-in;virtual technique;LabVIEW- 50
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Published：2020-08-12 -
Optimal sensor placement for thermal error identification of NC machine tools based on LS-SVM and genetic algorithms
Abstract：A novel method based on least squares support vector machine and genetic algorithm to select temperature sensors of NC machine tool was presented. The measurement points were grouped based on the thermal mode theory. Then the genetic algorithm was used to determine the optimum sensors’ positions. Thermal error regression model was given by the least squares support vector machine (LS-SVM) finally. The compensation model is made for machine tools. The result shows that the two methods of genetic algorithms and LS-SVM were combined well which not only avoided the correlation of the temperature sensors and ensured the accuracy of the model but also saved the cost and shortened the modeling time.Keywords：genetic algorithms;temperature sensor;least squares support vector machine;NC machine tool- 36
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Published：2020-08-12 -
Method of repeat sun-synchronous orbit design based on Q value selection
Abstract：Repeat sun-synchronous orbit is one of the most frequently used orbits for earth observation missions, because the orbit can satisfy the requirement of illumination and temporal resolution. Q value is the connection between sun-synchronous orbit and repeat orbit, so Q value, which is one of the first considerable parameters in the design of repeat sun-synchronous orbit, plays an important role of repeat sun-synchronous orbit design. First of all, the characteristics of sun-synchronous orbit and repeat orbit are analyzed, and the relationship of Q value and repeat sun-synchronous orbit is established, according as which repeat sun-synchronous orbit can be designed. Second, with the analysis of repeat orbit characteristics, derive a Q value design method of repeat sun-synchronous orbit. In the end, it is presented how to design a repeat sun-synchronous orbit satisfying mission requirements with an example. The method finds the key point of repeat sun-synchronous orbit design in theory, and provides a credible and easy method for complex orbit design tasks.Keywords：repeat sun-synchronous orbit;Q value;fictitious node;nodal period;fundamental interval- 59
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Published：2020-08-12 -
Design of angular automatic calibration mechanism for laser tracker system
Abstract：Laser tracker system (LTS) is one of the latest portable three dimensional large size coordinate measuring machines (CMMs). It can measure moving object 3D coordinates using the technology of laser interferometer length measurement, precision angle measurement and target tracking. However, its measuring accuracy is profoundly affected by the target retro-reflector receivable angle, in order to resolve the problem that LTS can not continuously measure corner cube retro-reflector (CCR) position in dynamic conditions restricted by CCR’s receivable angle; we have developed an angular automatic calibration mechanism for LTS to measuring the CCR positions in real time. The calibration mechanism mainly includes precision circular guide-way and angular automatic adjustment device, which can make the CCR always tracking the laser beam emitted from LTS all the time. The designed calibration mechanism and Hexagon Globle9128 coordinate measuring machine are used to compensate the angular measuring error of LTS. The experimental results demonstrate that the maximum angular measuring error of LTS in measuring distance of 0.752m has been decreased sharply from 34.69µm to 9.71µm in horizontal direction and 35.43µm to 10.03µm in vertical direction. Therefore, the LTS angular measuring accuracy is effectively improved.Keywords：laser tracker system;angle;calibration mechanism;corner cube retro-reflector- 65
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Published：2020-08-12 -
Research on Gap-filling of Copper in Micro-electroplating Process with N’N-Diethylthiourea Additive
Abstract：In order to investigate the copper gap-filling during micro electroplating process with additive (N’N-diethylthiourea), the electrochemical behaviors of electrolyte were studied by SEM, CVS and XRD, the electrode dynamics parameters were studied by the Tafei equation. The results show when N’N-diethylthiourea was used during micro electroplating copper process, activation polarization was generated; the activation energy was improved; metal ion discharge rate was lowered from 2.2214 mA/ cm2 to about 0.076 mA/ cm2; the overpotential was increased, thus the crystal nucleus molding speed on the electrode was accelerated; the crystal growth speed was decreased from 2.57μm /min to about 0.17μm /min, leveling ability was increased about 50%. Side effect was lowered effectively, which make the copper ions with good ability of micro-trenches or micro-contacts filling. Further more, some micro trenches in the silicon wafer, the width is 10μm and aspect ratio is 4:1, were filled by micro electroplating process with N’N-diethylthiourea, however the electroplating layer have no voids or seams.Keywords：Micro-electroplating process;N’N-Diethylthiourea;Activation polarization;Electrochemical behavior;Gap-filling- 67
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Published：2020-08-12 -
Development of Hot Rheologic Deformation Puller for Fabricating Vitreous Three-way Microchannels
Abstract：Hot rheologic deformation puller to fabricate vitreous three-way microchannels with round cross sections was designed. In the forming process of the three-way microchannels, the tip of the bended glass capillary with the shape of “V” is softened by heating, and then pulled into three-way microchannels in the process of cooling. Reservoirs which connect the microchannels with conical pipes form during the pulling process. The three-way microchannels with both equal or unequal inner diameter can be made by the puller. The temperature in the heating field can be controlled by heating time. The inner diameter of the microchannels can be controlled by pulling distance. The distribution coefficient of the vitreous material can be adjusted by micro-feed mechanism. The prepared three-way microchannels has better flatness, so that the microchannel network can be assembled expediently. The inner diameter of the microchannels are micron-sized, the internal surface of the three microchannels connect smoothly in the joint. High quality surface of the microchannels are obtained due to the surface tension. The microchannel networks were assembled with the one-dimension microchannels and the three-way microchannels. The microchannels are made by the puller with Non-IC technology, the whole process is simple and cheap. The puller has no special requirement of working environment, common analytical laboratory is acceptable.Keywords：microfluidic;microchannel puller;three-way microchannels;microchannel networks- 52
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Published：2020-08-12 -
The Research of Gyro Decoupling Problem on Photo-electric Platform
Abstract：Rotation of photo-electric platform leads to velocity coupling of Gyro, and that affects stabilization of platform. The paper analysis and discusses the Gyro decouple for two-axis and three-axis photo-electric platform, and a resolved method and a decouple software and hardware circuit are given. The experiments data indicates: About the roll axis, coupling input amplitude value of 22mV decreases to 3mV, coupling degree decreases 86.4%. It improves the control performance and stabilization accuracy when the platform is turning with a high speed.Keywords：rate gyro;decouple;ARM;inertial navigation- 56
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Published：2020-08-12 -
Study on acoustic landmine detection and its signal processing method
Abstract：In order to investigate the mechanism of acoustic landmines detection, an acoustic-to-seismic coupling based experimental system was developed. And curve-fitting method was adopted to study the measured complex signals. Firstly, acoustic-to-seismic coupling theory was briefly described, and the resonance mechanism of soil-mine system was analyzed. Then a loudspeaker and a geophone array were employed to induce and receive the ground vibration respectively. Finally, average algorithm was used to fit the curves of ground vibration velocity, and experimental phenomenon was explained. Experimental results indicate that the ratio of ground vibration velocity on-to-off mine appears greater than 1 in wide frequency range, up to 24. It proves that landmines can result in distinct changes of ground vibration and the presented experimental system and curve-fitting method are applicable for further study of acoustic landmines detection signals.Keywords：Acoustic landmines detection;Curve-fitting;Acoustic-to-seismic coupling;signal processing- 57
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Published：2020-08-12 -
Form measurement based on generalized
Abstract：Abstract：For aquring the mean line of workpiece form, a new kind of digital smoothing filters based on cubic generalized spline function is proposed. Firstly, generalized B spline functions are derived from the linear differential equation. Combining with generalized B spline functions and variational principles, the digital smoothing filters are deduced which compose of IIR filter and indirect generalize B spline transform. Then recursive algorithms of these filters are presented concretely, and the filter’s universal property is testified. Finally, This filter process is appied on a workpiece to acqure mean line. Experimental results indicate these filters take on a better cut-off property than the Gauss fiter, and total calculation only requires 0.002 second for 11200 data points on PC. These filters possess adjustable smoothing property and zero phase transmission, and overcome the drawbacks of low curvature and several oscillations of classical cubic spline interpolation. The recusive algorithm is a efficient and simple.Keywords：Generalized B spline function;smoothing spline filter;form measurement- 89
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Published：2020-08-12 -
Research on Close-loop control of inchworm-type piezoelectric actuator
Abstract：According to the output performance of inchworm-type piezoelectric actuator, proposed a novel close-loop control method which was based on the subsection experiential equation between actuating voltage and corresponding stepping motion displacement. Via that method, the control system could search for the optimal actuating voltage step by step so as to approach target position. Carried on experiment to the closed-loop system of the inchworm-type piezoelectric rotary actuator. The experimental results showed that the novel method could control the actuator for precision positioning in closed-loop mode, and the position precision was improved by 14.4% compared to the open-loop working mode. The control method had the advantages of high accuracy, quick response and et al.- 48
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Published：2020-08-12 -
An Improved Self-Organized LLE Algorithm for Face Recognition
Abstract：Manifold learning method can discover intrinsic low-dimensional submanifold embedded in the high-dimensional image space, it attracts more and more attention in the research area of biometrics and cognitive science. For the problem exits in locally linear embedding (LLE) algorithm, a self-organized LLE algorithm is proposed in this paper. This new method can not only determine the nearest neighbors of LLE automatically, save lots of operation, but also gain a perfect approximation of face manifold. This paper proposed theoretical analysis for details and applied to some dataset to verify the effeteness of this method. Experimental results on public face databases show that the proposed method can improves face classification performance effectively.Keywords：face recognition;manifold learning;locally linear embedding;Self-Organizing Maps- 60
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Published：2020-08-12 -
Invertible chaotic three-dimensional map based Image encryption approach and its optimized algorithm
Abstract：An invertible chaotic 3D map based image ecnryption approach and its optimized algorithm are proposed utilizing the stretch and fold mechanism of chaos. A gray-level image is firstly depicted as a 3D matrix. Then the 3D matrix is mapped to a 2D image matrix according to the proposed algorithm. Stretch and fold maps are used to permute pixel positions of the 2D matrix. The stretch process is to transform the 2D image matrix to an array, while the fold process is to fold the array to another 2D image matrix which is the same size as the original 2D matrix. At last, the permuted 2D matrix is mapped back to a 3D matrix, cipher image is achieved. This proposed approach is invertible, it could be used for image encryption and decryption. The encryption and decryption algorithms are formulated. Since image has large data quality, if the deduced formulas are used for image encryption and decryption, there will be large amount of calculation and long encryption and decryption time. In order to solve this problem, an optimized algorithm is proposed. Image encryption and decryption experiments were did and key sensitivity,correlation coefficients of two adjacent pixels and the time used for image encryption and decryption are tested. The results show that proposed image encryption approach realize pixel permutation and substitution at the same time via one iteration map, it change the histogram information of the plain image, enhance the capability of resisting statistic attack, have big key space. The proposed optimized algorithm obviously increase image encryption speed, it is faster than using the deduced formulas about 3 to 4 times.Keywords：image encryption;invertible 3D map;Chaos- 52
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Published：2020-08-12 -
Research for Characteristics of Neuron Transient Outward
Abstract：Abstract: Objective: With the develop of the modern industry ,magnetic field has become far more extensive effect to human body. Many magnetic healing instruments for different disease have come out, and some do have curative effect, but the mechanism of magnetic healing is not classified. This context has studied the effect of pulsating magnetic fields to rat cortical neurons. Transient outward K+ channel can maintain the rest potential and control the excitement of excitable cells .Method: This experiment use pulsating magnetic fields that frequency is 15Hz and the intensity is 1.4mT impose on the acutely isolated rat cortical neurons, and properties of transient outward K+ channel were studied using the whole-cell patch clamp technique. Result: The experiment revealed pulsating magnetic fields reduce the amplitudes of IA . Pulsating magnetic fields significantly affected the activation process of IA. The half-activation voltage and the slope factor of the activation curves changed by the pulsating magnetic fields’ exposure. The former altered from(13.25±2.22)mV to (30.98±4.11)mV（n＝6, P<0.05）and the latter from (24.00±2.05)mV和(23.30±2.13)mV（n=6,P<0.05）. Conclusion: The results show that pulsating magnetic fields can change the properties of transient outward K+ channel. Thus, the form and firing frequency of action potential is affected. Further, physiological functions of neurons are adjusted as a result of pulsating magnetic fields, which might contribute to the restoration and regeneration of damaged neurons.Keywords：transient outward potassium current;patch clamp technique;pulsating magnetic fields;biological effect;neurons- 49
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Published：2020-08-12 -
A data collection method with hybrid sinks in wireless sensor networks
Abstract：The lifetime of wireless sensor networks can be improved by introducing mobile sinks. A data collection method is proposed in order to support hybrid sink mode in wireless sensor networks where static and mobile sinks coexist. One or more mobile sinks cooperate with the static sink(s). These mobile sinks broadcast status update periodically to only a subset of adjacent nodes. Sensor nodes send or forward data packets to the sink which is the nearest in hop counts. The correct data transmission between the mobile sinks and the last hop sensor node is guaranteed by using ACK-RETRANSMIT method. Using this method, the network lifetime improves with the increase of the number of mobile sinks. Simulation study shows that more than 600% lifetime improvement achieves when the ratio of the mobile sinks to the sensor nodes is above 7.5%. When the load of network is high, the maximum success rate of data transmission achieves 91%, which is 8.3 times compared to the network with only one static sink. Meanwhile, data transmission delay remains at a low level.Keywords：Wireless sensor networks;Mobile sink;Hybrid sinks;Data collection- 37
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Published：2020-08-12 -
A Robust Algorithm Nonstationary Degree for Ultrasonic Data Enhancement in Stereoechography
Abstract：Objective: The stereoechography is kind of technique to realize 3-Dimension (3D) ultrasound visualization. It could explore the body inside of human and give the organ structure directly. Since the ultrasonic data are of poor quality and particularly noisy because of the speckles, we propose a new algorithm to solve this problem. Method: We present a algorithm by calculating the Nonstationary Degree of the image which could enhance the edge the image so that enhance the image and promote the quality. Result: We put the algorithm on the application to the stereovisual ultrasonic image about a liver of a rabbit and the 12-week infant. Conclusion: The stereovisual ultrasonic images enhanced by calculating the Nonstationary Degree of the image show a great improvement compare with the original ones. We could see the tissular structure clearly from the image.- 60
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Published：2020-08-12 -
Low-noise and wide-band design of composite preamplifier in the Quadrupole mass spectrometer
Abstract：Concerning the preamplifier to measure the ultra low current in the Quadrupole mass spectrometer, low noise and wide bandwidth is the key to this system as the current is from 10-11A to 10-6A and varies quickly. So we design the Non-inverting input composite preamplifier (NIICP), and analyze the open-loop gain (ac) to optimize the frequency response of signal and noise. In the lower magnification, the circuit optimizes ac to reduce intrinsic noise. In the higher magnification, the circuit optimizes ac to recover high frequency signal which is damped down by the low pass transfer function of the large feedback resistance and parasitic capacitance. Compared with inverting input composite preamplifier (IICP) in the commercial Quadrupole mass spectrometer, experimental results indicate that NIICP reduces 5-30% in the 106-107V/A magnification, expands signal bandwidth 1.8 times and increases 10-15% MS peak signal amplitude in the 108 V/A magnification, improves the SNR of MS peaks detection.Keywords：Mass spectrometer;composite preamplifier;low noise;wide bandwidth- 44
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Published：2020-08-12 -
A novel fingerprint recognition algorithm based on wavelet transform, two-dimensional principal component analysis and EBF
Abstract：Fingerprint recognition is a very important question in pattern recognition. Combined with wavelet transform (WT)， two-dimensional principal component analysis(2DPCA) and Ellipsoidal Basis Function (EBF), a novel fingerprint recognition algorithm has been proposed in this paper, which is based on wavelet transform, two-dimensional principal component analysis and EBF neural network. Firstly, original images are decomposed into high-frequency and low-frequency components with the help of WT , and high-frequency components are ignored, so the prime features of original images can be attained．Secondly, the projected features are solved by 2DPCA．Finally，fingerprint recognition can be realized by Ellipsoidal Basis Function Neural Network(EBFNN). The algorithm combines the optimization of the 2DPCA and the adaptability of EBFNN. The experimental results based on FVC2000 have verified that the proposed algorithm has higher recognition rate than WT-PNN and WT-2DPCA-RBF.Keywords：Fingerprint Recognition;Two-Dimensional Principal Component Analysis (2DPCA);Ellipsoidal Basis Function (EBF;Wavelet Transform (WT)- 46
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Published：2020-08-12 -
An Image Encryption Scheme Based on Sequential CA
Abstract：Cellular Automata (CA) can exhibit fascinatingly complex behavior by dealing with the relations between the part and the whole. Due to the universality of CA model, many applications has been found in traditional cryptography and image processing. Combined with Cellular Automata Transforms (CAT) compression technologies, we propose an image encryption approach with enhanced security and much larger key space based on sequential CA The proposed image encryption scheme is suitable for optical realization based on the characteristics of simple parallelism structure of CA and satisfies the characteristics of convenient realization, very large number of security keys, fast encryption speed and low cost.Keywords：Cellular Automata;image process;image encryption;optical realization;key space- 55
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Published：2020-08-12 -
Studying optimization threshold of centroid algorithm
Abstract：By adopting appropriate threshold, the algorithm of threshold centroid can get better results. The optimization threshold varies with influences of Signal-to-Noise Ratio, star point location and optical structure. Threshold obtained by traditional method can not satisfy the request of dynamic optimization for the centroid algorithm. By analyzing many kinds of influencing factors, a method of obtaining the optimization threshold based on luminosity of star spot was advanced. By studying the relationship between optimization threshold and luminosity of the spot, a curve model was produced. Based on luminosity of the spot, the optimization threshold was obtained by interpolation. The simulation results show that the algorithm can obtain the optimization threshold. Compared to traditional threshold, it can raise centroid accuracy with different Signal-to-Noise Ratio.- 49
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Published：2020-08-12
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