2014
2014
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Record 133 of
Title:Development of a chip-based ingroove microplasma source: Design, characterization, and diagnostics
Author(s):Li, Xuemei(1); Tang, Jie(2); Meng, Fanying(1); Yuan, Xin(1); Yan, Yanyue(1); Zhao, Zhongjun(1); Duan, Yixiang(1)Source: Applied Physics Letters Volume: 104 Issue: 10 DOI: 10.1063/1.4867484 Published: March 10, 2014Abstract:A chip-based ingroove microplasma source was designed for molecular emission spectrometry by using a space-confined direct current duct in air. The voltage-current characteristics of different size generators, emission spectroscopy of argon were discussed, respectively. It is found that the emission intensity of excited Ar and N2 approaches its maximum near the cathode, while OH and O peaks most likely appear close to the anode. The electron density, electronic excitation temperature, rotational temperature, and vibrational temperature of the argon plasma were also calculated. More importantly, the chip-based ingroove microplasma shows much better stability compared with its counterparts. ? 2014 AIP Publishing LLC.Accession Number: 20141217496322 -
Record 134 of
Title:Mode locked fiber laser based on single-walled carbon nanotube in heavy water
Author(s):Yu, Zhenhua(1); Wang, Yonggang(2); Tian, Jinrong(1); Dou, Zhiyuan(1); Li, Kexuan(1); Song, Yanrong(1)Source: IEEE Photonics Technology Letters Volume: 26 Issue: 18 DOI: 10.1109/LPT.2014.2336873 Published: September 15, 2014Abstract:Carbon nanotubes in heavy water (deuteroxide, D2O) dispersion was fabricated and used as a saturable absorber for mode locking in a fiber laser. Such liquid absorber has the virtues of good optical transparency, high heat dissipation, and high damage threshold. A passively mode locked fiber laser with it was demonstrated. The pulsewidth is 306 fs with the maximum average output power of 20 mW. The center of the wavelength is 1560 nm with 15.2-nm spectral width. ? 1989-2012 IEEE.Accession Number: 20143618123293 -
Record 135 of
Title:Improved adaptive control for wing rock via fuzzy neural network with randomly assigned fuzzy membership function parameters
Author(s):Rong, Hai-Jun(1); Han, Sai(2); Bai, Jian-Ming(3); Liang, Yong-Qi(1)Source: Aerospace Science and Technology Volume: 39 Issue: DOI: 10.1016/j.ast.2014.06.009 Published: December 2014Abstract:Two stable adaptive fuzzy-neural control schemes within the indirect and direct frameworks are proposed to suppress the wing rock occurring at high angles of attack. In the two control strategies, a fuzzy neural network (FNN) with any bounded nonconstant piecewise continuous membership function is used to approximate the system nonlinear dynamics and external disturbances. Differently from the existing techniques, the parameters of the fuzzy membership functions are determined based on the recently developed fuzzy-neural algorithm named online sequential fuzzy extreme learning machine (OS-Fuzzy-ELM) where the fuzzy membership function parameters need not be adjusted and could randomly be generated according to any given continuous probability distribution without any prior knowledge. This simplifies the design of the controllers. Furthermore to ensure stable control performance, the tuning laws of the consequent parameters are derived using the projection algorithm and Lyapunov stability theorem. The merits of the proposed control schemes lie in the simplicity, robustness and stability, which manifests they can be applied for online learning and real-time control. In order to evaluate the performance of the proposed two control schemes, a comparison between a neural control, a fuzzy control and a fuzzy-neural control is carried out on various initial conditions. Results indicate the performance of the proposed controllers is superior using the randomly assigned fuzzy membership function parameters. ? 2014 Elsevier Masson SAS.Accession Number: 20144800260585 -
Record 136 of
Title:Design of large aperture off-axis middle infrared continuous zoom lens
Author(s):Wang, Da-Bao(1); Jiang, Kai(2); Zhao, Shi-Min(3); Hao, Wei(2); Jiang, Bo(2); Zhou, Si-Zhong(2)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 43 Issue: 6 DOI: 10.3788/gzxb20144306.0622004 Published: June 2014Abstract:On the basics of a cool 320×240 detector with staring focal plane array, a off-axis catadioptric middle infrared continuous zoom system with large aperture and long focal length is designed. The optical system was divided into two segments. First an off-axis aspheric non-power system as the front system was designed, then the continuous zoom lens which matched with the non-power system as the back system was designed. Because of the material constraint, the refractive zoom system can't realize large aperture. Coaxal catadioptric zoom system has great block ratio. And three mirrors zoom system can't achieve cold shield efficiency 100%. The off-axis catadioptric zoom system can account for forenamed limitation. The system worked at 3.7~4.8 μm has achieved the zoom of 250 mm to 2 000 mm and F number of 4. This system can offer a high resolution and excellent images, and its cold shield efficiency is 100%. The system satisfies the design requirements.Accession Number: 20142917960002 -
Record 137 of
Title:Facial skin beautification using adaptive region-aware masks
Author(s):Liang, Lingyu(1); Jin, Lianwen(1); Li, Xuelong(2)Source: IEEE Transactions on Cybernetics Volume: 44 Issue: 12 DOI: 10.1109/TCYB.2014.2311033 Published: December 1, 2014Abstract:In this paper, we propose a unified facial beautification framework with respect to skin homogeneity, lighting, and color. A novel region-aware mask is constructed for skin manipulation, which can automatically select the edited regions with great precision. Inspired by the state-of-the-art edit propagation techniques, we present an adaptive edge-preserving energy minimization model with a spatially variant parameter and a high-dimensional guided feature space for mask generation. Using region-aware masks, our method facilitates more flexible and accurate facial skin enhancement while the complex manipulations are simplified considerably. In our beautification framework, a portrait is decomposed into smoothness, lighting, and color layers by an edge-preserving operator. Next, facial landmarks and significant features are extracted as input constraints for mask generation. After three region-aware masks have been obtained, a user can perform facial beautification simply by adjusting the skin parameters. Furthermore, the combinations of parameters can be optimized automatically, depending on the data priors and psychological knowledge. We performed both qualitative and quantitative evaluation for our method using faces with different genders, races, ages, poses, and backgrounds from various databases. The experimental results demonstrate that our technique is superior to previous methods and comparable to commercial systems, for example, PicTreat, Portrait+, and Portraiture. ? 2014 IEEE.Accession Number: 20144900275615 -
Record 138 of
Title:Method for improving reconstructed image quality of digital hologram based on SRAD and NSCT
Author(s):Wu, Yiquan(1,2); Yin, Jun(1); Zhu, Li(1); Ye, Zhilong(1)Source: Zhongguo Jiguang/Chinese Journal of Lasers Volume: 41 Issue: 2 DOI: 10.3788/CJL201441.0209024 Published: February 2014Abstract:Reconstructed image of digital holography has problems such as serious interference of speckle noise, low contrast and so on. Thus a method based on speckle reducing anisotropic diffusion (SRAD) model and nonsubsampled contourlet transform (NSCT) is proposed for improving reconstructed image quality of digital hologram. SRAD model is adopted to eliminate speckle noise of reconstructed image. After NSCT decomposition, a low-frequency sub-band and several high-frequency sub-bands are produced. Low-frequency sub-band coefficients are adjusted based on a nonlinear gain function and an image segmentation method. In high-frequency sub-bands, edges are enhanced using a NSCT modulus maximum edge detection method. A large number of experimental results show that, compared with nonlinear diffusion denoising methods and NSCT enhancement methods proposed recently, the proposed method can more effectively eliminate speckle noise and improve the contrast of reconstructed image. Furthermore, the edges are smooth and clear. As a result, the accuracy of recognition and measurement in digital holography can be improved.Accession Number: 20141317523978 -
Record 139 of
Title:Rank preserving discriminant analysis for human behavior recognition on wireless sensor networks
Author(s):Tao, Dapeng(1); Jin, Lianwen(1); Wang, Yongfei(1); Li, Xuelong(2)Source: IEEE Transactions on Industrial Informatics Volume: 10 Issue: 1 DOI: 10.1109/TII.2013.2255061 Published: February 2014Abstract:With the rapid development of the intelligent sensing and the prompt growing industrial safety demands, human behavior recognition has received a great deal of attentions in industrial informatics. To deploy an utmost scalable, flexible, and robust human behavior recognition system, we need both innovative sensing electronics and suitable intelligence algorithms. Wireless sensor networks (WSNs) open a novel way for human behavior recognition, because the heavy computation can be immediately transferred to a network server. In this paper, a new scheme for human behavior recognition on WSNs is proposed, which transmits activities' signals compressed by Hamming compressed sensing to the network server and conducts behavior recognition through a collaboration between a new dimension reduction algorithm termed rank preserving discriminant analysis (RPDA) and a nearest neighbor classifier. RPDA encodes local rank information of within-class samples and discriminative information of the between-class under the framework of Patch Alignment Framework. Experiments are conducted on the SCUT Naturalistic 3D Acceleration-based Activity (SCUT NAA) dataset and demonstrate the effectiveness of RPDA for human behavior recognition. ? 2005-2012 IEEE.Accession Number: 20140117151552 -
Record 140 of
Title:Mathematical model for the measurement of high dynamic range laser focal spot
Author(s):Wang, Zheng-Zhou(1,2); Wang, Wei(1,2); Xia, Yan-Wen(3)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 43 Issue: 10 DOI: 10.3788/gzxb20144310.1010002 Published: October 1, 2014Abstract:A measurement method of the high dynamic range laser focal spot was proposed. First of all, the mathematical model of schlieren method to measure the far-field focal spot was constructed, the main lobe intensity amplification coefficient and the laser spot amplification coefficient were confirmed, and the parameters were calibrated by automatic alignment laser beam; Secondly, the schlieren ball was put in focus position of side lobe laser beam to shade the spot centre and side lobe image was captured accurately by integrated diagnostic beam fast automatic alignment system; Finally, the schlieren reconstructed algorithm was optimized by calculating side lobe image centre and image fusion, and the error of traditional schlieren reconstruction method for side lobe center was decreased and the obvious edge of reconstructed image was eliminated. The application in parameter measurement integrated diagnostic system of the high power laser facility to measure far-field laser focal spot shows that the method can measure the far field distribution of high dynamic range laser focal spot exactly if the parameter of the mathematical model is calibrated accurately and the schlieren reconstructed algorithm is optimized.Accession Number: 20144700217739 -
Record 141 of
Title:High time resolution scanning imaging technique research based on area CCD
Author(s):Jin, Jing(1,2); Bai, Yong Lin(2); Yang, Wen Zheng(2); Zhu, Bing Li(2); Wang, Bo(2); Gou, Yong Sheng(2); Wang, Qiao Li(1)Source: Applied Mechanics and Materials Volume: 644-650 Issue: DOI: 10.4028/www.scientific.net/AMM.644-650.4244 Published: 2014Abstract:A new transient spectrum detection method with high time resolution based on area CCD is proposed. By reforming and mending working sequence of CCD, utilizing principle of frame restore, linear spectrum detection with high time resolution was achieved. This method improves frame rate and time resolution of CCD greatly. LED impulse light experiment is performed to demonstrate feasibility of the method. Experiment results show that this transient spectrum acquisition method based on area CCD is efficacious, detection frame rate can be as high as 10Mfps. Time resolution is less than 100ns, and can be able to image 2048 times continuously. The experiment is of importance to expand application of CCD in the transient spectrum detection area. ? (2014) Trans Tech Publications, Switzerland.Accession Number: 20145000310982 -
Record 142 of
Title:Research of the immersion grating diffraction pattern
Author(s):Tang, Qian(1,2); Qiu, Yue-Hong(1); Zhao, Bao-Chang(1); Chen, Li-Wu(3)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 43 Issue: 11 DOI: 10.3788/gzxb20144311.1105002 Published: November 1, 2014Abstract:Based on the difference between nomal grating and immersion grating, the immersion grating equation was deduced. Immersion medium absorption was studied as the reason of the single slit diffraction and the change of the multiple beam interference intensity distribution. The correction factors of single slit diffraction and multiple beam interference were concluded, and the intensity distribution formula considering the medium absorption was deduced. The formula is more general and the single slit diffraction intensity distribution formula, the multi-slit diffraction intensity distribution formula and the parallel-plate multiple beam interference intensity distribution formula are special cases of the correction formula. ?, 2014, Chinese Optical Society. All right reserved.Accession Number: 20144900301549 -
Record 143 of
Title:Hybrid adaptive robust controller on inertial Gyro LOS platform
Author(s):Luo, Cui Hua(1,2,3); Ma, Cai Wen(2); Li, Yan(2)Source: Applied Mechanics and Materials Volume: 513-517 Issue: DOI: 10.4028/www.scientific.net/AMM.513-517.2910 Published: 2014Abstract:This paper was presented one new modified controller scheme for inertial gyro control system. Based on Narendra's hybrid adaptive law, the modified algorithm was variable metric that took use of parameter matrix Γk to obtain two updating laws in turn online. The key modified contents were: 1) the output y(t)was passed by one low-pass filter, 2) the parameter was updating in term of one proper initial Γ0 and the measurable values. The objective of the proposed new adaptive robust control schemes was to achieve fast convergence of parameter updating, and promise good robust stability of control system during tracking, reduce the tracking error at start-time with filtered output. ? (2014) Trans Tech Publications, Switzerland.Accession Number: 20141117458167 -
Record 144 of
Title:Robust superpixel tracking via depth fusion
Author(s):Yuan, Yuan(1); Fang, Jianwu(1); Wang, Qi(1)Source: IEEE Transactions on Circuits and Systems for Video Technology Volume: 24 Issue: 1 DOI: 10.1109/TCSVT.2013.2273631 Published: January 2014Abstract:Although numerous trackers have been designed to adapt to the nonstationary image streams that change over time, it remains a challenging task to facilitate a tracker to accurately distinguish the target from the background in every frame. This paper proposes a robust superpixel-based tracker via depth fusion, which exploits the adequate structural information and great flexibility of mid-level features captured by superpixels, as well as the depth-map's discriminative ability for the target and background separation. By introducing graph-regularized sparse coding into the appearance model, the local geometrical structure of data is considered, and the resulting appearance model has a more powerful discriminative ability. Meanwhile, the similarity of the target superpixels' neighborhoods in two adjacent frames is also incorporated into the refinement of the target estimation, which helps a more accurate localization. Most importantly, the depth cue is fused into the superpixel-based target estimation so as to tackle the cluttered background with similar appearance to the target. To evaluate the effectiveness of the proposed tracker, four video sequences of different challenging situations are contributed by the authors. The comparison results demonstrate that the proposed tracker has more robust and accurate performance than seven ones representing the state-of-the-art. ? 2013 IEEE.Accession Number: 20140417224667