2017
2017
-
Record 349 of
Title:Measuring dispersed spot of positioning CMOS camera from star image quantitative interpretation based on a bivariate-error least squares curve fitting algorithm
Author(s):Bu, Fan(1); Qiu, Yuehong(1); Yao, Dalei(1); Yan, Xingtao(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10250 Issue: DOI: 10.1117/12.2266810 Published: 2017Abstract:For a positioning CMOS camera, we put forward a system which can measure quantitatively dispersed spot parameters and the degree of energy concentration of certain optical system. Based on this method, the detection capability of the positioning CMOS camera can be verified. The measuring method contains some key instruments, such as 550mm collimator, 0.2mm star point, turntable and a positioning CMOS camera. Firstly, the definition of dispersed spot parameters is introduced. Then, the steps of measuring dispersed spot parameters are listed. The energy center of dispersed spot is calculated using centroid algorithm, and then a bivariate-error least squares curve Gaussian fitting method is presented to fit dispersion spot energy distribution curve. Finally, the connected region shaped by the energy contour of the defocused spots is analyzed. The diameter equal to the area which is 80% of the total energy of defocused spots and the energy percentage to the 3×3 central area of the image size are both calculated. The experimental results show that 80% of the total energy of defocused spots is concentrated in the diameter of the inner circle of 15μm, and the percentage to the 3×3 pixels central area can achieve 80% and even higher. Therefore, the method meets the needs of the optical systems in positioning CMOS camera for the imaging quality control. ? 2017 COPYRIGHT SPIE.Accession Number: 20171403518578 -
Record 350 of
Title:Novel long-period fiber gratings: Fabrication and sensing applications
Author(s):Ren, Liyong(1); Ren, Kaili(1,2); Kong, Xudong(1); Liang, Jian(1); Ju, Haijuan(1); Wu, Zhaoxin(2)Source: Optics InfoBase Conference Papers Volume: Part F43-CLEO_AT 2017 Issue: DOI: 10.1364/CLEO_AT.2017.AW4B.6 Published: 2017Abstract:We presented two novel schemes for fabricating micro-tapered long-period fiber gratings (LPFGs) and helical LPFGs, respectively, by periodically tapering and by directly twisting single mode fibers. Superior sensing characteristics of them are also demonstrated experimentally. ? 2017 OSA.Accession Number: 20172403762827 -
Record 351 of
Title:Li3PO4-added garnet-type Li6.5La3Zr1.5Ta0.5O12 for Li-dendrite suppression
Author(s):Xu, Biyi(1); Li, Wenlong(2,3); Duan, Huanan(1); Wang, Haojing(2,3); Guo, Yiping(1); Li, Hua(1); Liu, Hezhou(1)Source: Journal of Power Sources Volume: 354 Issue: DOI: 10.1016/j.jpowsour.2017.04.026 Published: 2017Abstract:This paper proposes a strategy to stabilize the garnet/Li interface by introducing Li3PO4 as an additive in garnet-type Li6.5La3Zr1.5Ta0.5O12. The Li3PO4-added Li6.5La3Zr1.5Ta0.5O12 electrolyte exhibits a room-temperature Li-ion conductivity of 1.4?×?10?4?S?cm?1, which is less than that of the Li3PO4-free counterparts (4.6?×?10?4?S?cm?1). However, the presence of Li3PO4 improves the interfacial compatibility and suppresses Li-dendrite formation during Li-metal plating/stripping. The symmetric Li/garnet/Li cells with Li3PO4-added Li6.5La3Zr1.5Ta0.5O12 have been successfully cycled at a current density of 0.1?mA?cm?2 at 60?°C for 60?h; on contrast, the control cells with Li3PO4-free Li6.5La3Zr1.5Ta0.5O12 display noisy potential with large voltage polarization and get short-circuited completely after 33-h cycling under the same operating condition. The outstanding interface stability can be attributed to the in situ reaction of the Li flux with Li3PO4 to form a self-limiting and ion-conducting interphase, Li3P, which is confirmed experimentally. ? 2017 Elsevier B.V.Accession Number: 20171603572063 -
Record 352 of
Title:Nonlinear optical response and applications of tin disulfide in the near- and mid-infrared
Author(s):Yang, H.R.(1,2); Liu, X.M.(1,2,3)Source: Applied Physics Letters Volume: 110 Issue: 17 DOI: 10.1063/1.4982624 Published: April 24, 2017Abstract:Layered metal dichalcogenides (LMDs) have received considerable attention in optoelectronics and photonics. Tin disulfide (SnS2) as a member of the LMDs has been employed for transistors, energy storage, and photocatalysts. The optical properties of SnS2 in the ultraviolet and visible regions have been widely investigated, while the applications of SnS2 in the near- and mid-infrared regions are still rare. Here, we demonstrate the nonlinear optical response of layered SnS2 that is exploited as a saturable absorber in the near- and mid-infrared regions. The saturable absorption of SnS2 is measured at 1.06 and 1.55 μm, which illustrates a low saturable intensity. SnS2 covered on a D-shaped fiber is used to initiate the mode-locking operations in erbium-, ytterbium-, and thulium-doped fiber lasers and ultrafast pulses are achieved at 1.03, 1.56, and 1.91 μm. These results make SnS2 an appealing candidate for broadband applications across the near- and mid-infrared regions. ? 2017 Author(s).Accession Number: 20171803628642 -
Record 353 of
Title:Object discovery via cohesion measurement
Author(s):Guo, Guanjun(1); Wang, Hanzi(1); Zhao, Wan-Lei(1); Yan, Yan(1); Li, Xuelong(2)Source: arXiv Volume: Issue: DOI: Published: April 28, 2017Abstract:Color and intensity are two important components in an image. Usually, groups of image pixels, which are similar in color or intensity, are an informative representation for an object. They are therefore particularly suitable for computer vision tasks, such as saliency detection and object proposal generation. However, image pixels, which share a similar real-world color, may be quite different since colors are often distorted by intensity. In this paper, we reinvestigate the affinity matrices originally used in image segmentation methods based on spectral clustering. A new affinity matrix, which is robust to color distortions, is formulated for object discovery. Moreover, a Cohesion Measurement (CM) for object regions is also derived based on the formulated affinity matrix. Based on the new Cohesion Measurement, a novel object discovery method is proposed to discover objects latent in an image by utilizing the eigenvectors of the affinity matrix. Then we apply the proposed method to both saliency detection and object proposal generation. Experimental results on several evaluation benchmarks demonstrate that the proposed CM based method has achieved promising performance for these two tasks. Copyright ? 2017, The Authors. All rights reserved.Accession Number: 20200070423 -
Record 354 of
Title:Spatial Mode Distributions of Ince-Gaussian Beams Modulated by Phase Difference Factor
Author(s):Ma, Haixiang(1); Li, Xinzhong(1,2); Li, Hehe(1); Tang, Miaomiao(1); Wang, Jingge(1); Tang, Jie(2); Wang, Yishan(2); Nie, Zhaogang(3)Source: Guangxue Xuebao/Acta Optica Sinica Volume: 37 Issue: 6 DOI: 10.3788/AOS201737.0626002 Published: June 10, 2017Abstract:A novel type of Ince-Gaussian (IG) beam, named as PIG (Ince-Gaussian beam with phase difference) beam, based on the initial phase difference factor modulation between even mode and odd mode of IG beam is proposed. The PIG beam is generated by the linear superposition of the even mode and the odd mode of traditional IG beam after the even mode being multiplied an exponential phase factor with an initial phase difference of φ. The modulation properties of the initial phase difference factor on spatial mode of the PIG beam are mainly studied when other parameters are the same. Numerical simulations and experimental results show that the PIG beam changes from positive vortex state to negative vortex state when φ continuously increases from 0 to π. The vortex state is vanished when φ=π/2. As φ is equal to integer multiple of π, the switch from the positive vortex state to the negative vortex state is realized. As φ is equal to half-integer multiple of π, light traps of the PIG beams can be accurately controlled to move on the oval orbit. The PIG beam will provides an additional degree of freedom for micro-particle operation and beam micro-machining. ? 2017, Chinese Lasers Press. All right reserved.Accession Number: 20173003967983 -
Record 355 of
Title:Robust Sparse Coding for Mobile Image Labeling on the Cloud
Author(s):Tao, Dapeng(1); Cheng, Jun(2,3); Gao, Xinbo(4); Li, Xuelong(5); Deng, Cheng(4)Source: IEEE Transactions on Circuits and Systems for Video Technology Volume: 27 Issue: 1 DOI: 10.1109/TCSVT.2016.2539778 Published: January 2017Abstract:With the rapid development of the mobile service and online social networking service, a large number of mobile images are generated and shared on the social networks every day. The visual content of these images contains rich knowledge for many uses, such as social categorization and recommendation. Mobile image labeling has, therefore, been proposed to understand the visual content and received intensive attention in recent years. In this paper, we present a novel mobile image labeling scheme on the cloud, in which mobile images are first and efficiently transmitted to the cloud by Hamming compressed sensing, such that the heavy computation for image understanding is transferred to the cloud for quick response to the queries of the users. On the cloud, we design a sparse correntropy framework for robustly learning the semantic content of mobile images, based on which the relevant tags are assigned to the query images. The proposed framework (called maximum correntropy-based mobile image labeling) is very insensitive to the noise and the outliers, and is optimized by a half-quadratic optimization technique. We theoretically show that our image labeling approach is more robust than the squared loss, absolute loss, Cauchy loss, and many other robust loss function-based sparse coding methods. To further understand the proposed algorithm, we also derive its robustness and generalization error bounds. Finally, we conduct experiments on the PASCAL VOC'07 data set and empirically demonstrate the effectiveness of the proposed robust sparse coding method for mobile image labeling. ? 1991-2012 IEEE.Accession Number: 20170303265694 -
Record 356 of
Title:Beam dynamics in disordered P T -symmetric optical lattices based on eigenstate analyses
Author(s):Yao, Xiankun(1); Liu, Xueming(1,2,3)Source: Physical Review A Volume: 95 Issue: 3 DOI: 10.1103/PhysRevA.95.033804 Published: March 7, 2017Abstract:Wave functions will experience a localization process when evolving in disordered lattices. Here, we have demonstrated the effects of disordered PT-symmetric potentials on wave-function characteristics in optics based on eigenstate analyses. In weak-disorder cases, by using the tight-binding approximation method, a conclusion is obtained that the increasing of the imaginary part of potential can enhance the diffraction, while the increasing disorder will block the diffraction and lead to localization. In the general case, band theory is used for band-structure analysis of three bands. We find that the disorder has a smaller effect on the higher-order band, which is proved by the beam evolutions. Our work may be instructive for realizing beam path control by manipulating the strengths of disorder and gain and/or loss of lattice. ? 2017 American Physical Society.Accession Number: 20171103434613 -
Record 357 of
Title:Fast recovery method for fog image
Author(s):Wang, Zefeng(1); Yang, Hongtao(1); Zhang, Hui(1); Zhang, Haifeng(1); Liao, Jiawen(1); Zhang, Zhi(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10256 Issue: DOI: 10.1117/12.2257101 Published: 2017Abstract:The images of outdoor scenes obtained in haze, fog and other weather phenomena are usually have poor contrast and color fidelity. In order to get a clear view of the image taken under bad weather, this paper for the image degradation in fog and haze, we detailed analyzed the image degradation causes and fuzzy mechanism and made some meaningful work for improving the existing defogging method and introduing new ideas. The experimental results demonstrate the new method abilities to remove the haze layer as well as provide a reliable depth map. ? 2017 SPIE.Accession Number: 20171703607640 -
Record 358 of
Title:Two-dimensional simulation of argon dielectric barrier discharge excited by a Gaussian voltage at atmospheric pressure
Author(s):Xu, Yonggang(1,2); Wang, Jing(2); Li, Jing(2,3); Lei, Bingying(2); Tang, Jie(2); Wang, Yishan(2); Li, Yongfang(1); Zhao, Wei(2); Duan, Yixiang(2,4)Source: Physics of Plasmas Volume: 24 Issue: 4 DOI: 10.1063/1.4979898 Published: April 1, 2017Abstract:A two-dimensional self-consistent fluid model was employed to investigate the spatiotemporal characteristics of discharges in atmospheric pressure argon (Ar) dielectric barrier discharge driven by a Gaussian voltage. The simulation results show that a discharge with multiple current pulses occurs each half-cycle in the gas gap. A transition from the Townsend mode to the glow mode is observed with the increasing applied voltage each half-cycle at a lower driving frequency (7.5 kHz). It is also found that the glow mode survives all the discharge phases at a higher driving frequency (12.5 kHz and 40 kHz). The change in the discharge mode with the driving frequency mainly lies in the fact that a lot of charged particles created in the discharge gap have no enough time to drift and diffuse around, and then these particles are assembled in the discharge space at higher frequency. Additionally, the spatial distributions of the electron density indicate that a center-advantage discharge is ignited at the driving frequencies of interest, resulting in the radial non-uniformity of discharge because of the edge effects. However, this overall non-uniformity is weakened with the driving frequency increased to 40 kHz, at which concentric ring patterns are observed. These distinct behaviors are mainly attributed to the fact that many charged particles generated are trapped in the gas gap and then accumulated to make the extension along the radial direction due to the charged particles transport and diffusion, and that the effective overlapping of a large number of avalanches induced by the increased "seed" electron density with the driving frequency. Meanwhile, the surface charged particles accumulated on the dielectric barriers are also shown to play a role in the formation of the discharge structure. ? 2017 Author(s).Accession Number: 20171603579362 -
Record 359 of
Title:An adaptive gamma method for image under non-uniform illumination
Author(s):Wang, Zefeng(1); Zhang, Haifeng(1); Liao, Jiawen(1); Guo, Huinan(1); Zhang, Zhi(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10256 Issue: DOI: 10.1117/12.2256659 Published: 2017Abstract:Gamma correction is a necessary operation for a digital image before it is sent to display. Uneven illumination images have low resolution and a lot of information is covered.in order to better removal of light effects and reproduce truly plain circumstances, this paper presents a new local adaptive gamma correction method. The experiment shows this method makes the brightness distribution more uniform and proved that the method compared with other methods that have better correction results. ? 2017 SPIE.Accession Number: 20171703607632 -
Record 360 of
Title:Electromechanical coupling characteristics of optical-electric theodolite
Author(s):Zhang, Jing(1); Hao, Wei(1); Yang, Xiao-Xu(1); Jing, Feng(1); Huang, Wei(1); Qiu, Peng(1); Cao, Bei(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 46 Issue: 1 DOI: 10.3788/gzxb20174601.0112005 Published: January 1, 2017Abstract:Combing the structure dynamic design method with the control theory, the flexible electromechanical coupling control model was built which is difference from the traditional rigid control model. The relationship between the structural fundamental frequency and servo bandwidth was analyzed, then the dynamic quantitative design principles were put-forward, The experiment results show that, the theodolite structure frequency should be far away from the resonant frequency of the system, and meet ωn≥3ωr at least, which is effective and feasible, has solved the high precision large theodolite electromechanical resonance problem, and provide the basis of engineering for designing fast response and high tracking precision of photoelectric theodolite. ? 2017, Science Press. All right reserved.Accession Number: 20171103436800