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Record 73 of
Title:Advanced transient thermoreflectance 2D imaging for integrated circuit sub-micron defect detection and thermal analysis
Author(s):Yazawa, Kazuaki(1,3); Kendig, Dustin(1); Zhang, Yan(2); Shakouri, Ali(3)
Source: Proceedings of the International Symposium on the Physical and Failure Analysis of Integrated Circuits, IPFA Volume: Issue: DOI: 10.1109/IPFA.2013.6599139 Published: 2013
Abstract:Transient thermoreflectance 2D thermal imaging is rapidly proving to be an effective technique for meeting the thermal analysis challenges inherent with today's advanced high speed integrated circuits. Using near infrared light illumination is particularly suitable for the thermal imaging of flip chip mounted devices and silicon substrate chips. High speed transient imaging reveals the timing of heating the spots in the circuit to identify if it is designed or unintended heating. Time-dependent unusual thermal signals provide the information of the depth location of a failure by knowing the time delay underneath the opaque layers. ? 2013 IEEE.
Accession Number: 20134316874279
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Record 74 of
Title:1.5 kW incoherent beam combining of four fiber lasers using adaptive fiber-optics collimators
Author(s):Geng, Chao(1); Zhao, Baoyin(2); Zhang, Entao(2); Luo, Wen(1); Tan, Yi(1); Zhu, Yonggang(2); Yang, Hening(2); Mu, Jinbo(1); Li, Xinyang(1); Duan, Kailiang(2); Zhao, Wei(2)
Source: IEEE Photonics Technology Letters Volume: 25 Issue: 13 DOI: 10.1109/LPT.2013.2263123 Published: 2013
Abstract:We demonstrate the incoherent beam combining (BC) of four high-power single-mode fiber lasers. Adaptive fiber-optics collimators (AFOC) of 0.5 kW-level are developed to correct the tip/tilt-type phase errors among beamlets. The maximum deflection angle of the AFOC is about 0.29 mrad. A stochastic parallel gradient descent algorithm is employed as the tip/tilt control strategy. The tip/tilt control makes four separate laser beams overlap with each other in the far-field, and the average of normalized power-in-bucket increases from 0.171 in open loop to 0.798 in closed loop when 1.5-kW total output power is achieved. The precise tracking ability and control accuracy of this BC system are investigated. Experimental results expose that thermal-blooming effect disturbs BC seriously when the total output power is up to kW-level, which could be mitigated by inducing air flow near the laser output. ? 1989-2012 IEEE.
Accession Number: 20132916502356
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Record 75 of
Title:Energy measurement system of a large-Aperture high power laser experiment platform
Author(s):Xia, Yanwen(1); Liang, Yue(1); Li, Sen(1); Zhao, Junpu(1); Peng, Zhitao(1); Li, Hongguang(2); Liu, Hua(1); Sun, Zhihong(1); Zheng, Kuixing(1); Wei, Xiaofeng(1)
Source: High Power Laser Science and Engineering Volume: 1 Issue: 3-4 DOI: 10.1017/hpl.2013.21 Published: December 20, 2013
Abstract:An energy measurement system in a Large-Aperture high power laser experiment platform is introduced. The entire measurement system includes five calorimeters, which carry out the energy measurement of the fundamental frequency before the frequency conversion unit, remaining fundamental frequency, remain second-harmonics, third harmonics, as well as the energy balance measurement after the frequency conversion unit. Combinational indirect calibration and direct calibration are employed to calibrate the sampling coefficients of the calorimeters. The analysis of the data showed that, regarding the energy balance coefficients, combinational calibration approach gives a higher precision, and leads to an energy balance with 1%; and regarding the energy sampling coefficients for the various wavelengths after the frequency conversion, the results from direct and combinational calibration are consistent. The uncertainties for all energy sampling coefficients are within 3%, which guarantees the reliability of the energy measurement for the laser facility. ? The Author(s) 2014? The online version of this article is published within an Open Access environment subject to the conditions of the Creative Commons Attribution licence .
Accession Number: 20214511122947
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Record 76 of
Title:A FPGA-based real time QRS complex detection system using adaptive lifting scheme
Author(s):Yu, Hang(1); Ma, Lixiao(1,2); Wang, Ru(1,2); Jiang, Lai(1,2); Li, Yan(1,2); Ji, Zhen(1); Pingkun, Yan(3); Fei, Wang(4)
Source: Lecture Notes in Electrical Engineering Volume: 156 LNEE Issue: VOL. 1 DOI: 10.1007/978-3-642-28807-4_69 Published: 2013
Abstract:This paper presents a real time QRS wave detection system implemented using the FPGA. Based on the Adaptive Lifting Scheme, the digitized ECG sequence is directly processed in the spatial domain, thus greatly simplifies the system design and reduces the memory usage. In order to synchronize the input ECG sampling data and the FPGA based ALS system, a pipeline architecture interface is proposed. It works as a buffer and the ECG data is processed in a real time manner. The system is implemented on the XUPV5-LX110T evaluation platform, and validated by using ECG samples from the MIT-BTH Arrhythmia Database. Experimental results show that the system achieves 98.688% detection accuracy, while the dynamic power consumption is only ~20mW. ? 2013 Springer-Verlag GmbH.
Accession Number: 20123615405962
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Record 77 of
Title:Measurement systems of a large-aperture high power laser experiment platform
Author(s):Xia, Yanwen(1); Sun, Zhihong(1); Da, Zhengshang(2); Zhao, Junpu(1); Peng, Zhitao(1); Dong, Xiaona(2); Zheng, Kuixing(1); Liu, Hua(1)
Source: Guangxue Xuebao/Acta Optica Sinica Volume: 33 Issue: SUPPL.1 DOI: 10.3788/AOS201333.s112003 Published: June 2013
Abstract:The measurement systems of a large-aperture high power laser experiment platform ten kilojoule laser facility are introduced. These involve preamplifier diagnostic module, cavity diagnostic module and main-amplifier diagnostic module. The diagnostic parameters, such as near field, far field alignment, temporal profile, pulse energy and wavefront are measured, and data acquisition, storage and processing are accomplished automatically under the manipulation of control software. The accurate and reliable experimental data are given for the stabilized operation of laser facility.
Accession Number: 20133516678422
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Record 78 of
Title:Cloud3DView: An interactive tool for cloud data center operations
Author(s):Yin, Jianxiong(1); Sun, Peng(1); Wen, Yonggang(1); Gong, Haigang(2); Liu, Ming(2); Li, Xuelong(3); You, Haipeng(1); Gao, Jinqi(1); Lin, Cynthia(1)
Source: SIGCOMM 2013 - Proceedings of the ACM SIGCOMM 2013 Conference on Applications, Technologies, Architectures, and Protocols for Computer Communication Volume: Issue: DOI: 10.1145/2486001.2491704 Published: 2013
Abstract:The emergence of cloud computing has promoted growing demand and rapid deployment of data centers. However, data center operations require a set of sophisticated skills (e.g., command-line-interface), resulting in a high operational cost. In this demo, to reduce the data center operational cost, we design and build a novel cloud data center management system, based on the concept of 3D gamification. In particular, we apply data visualization techniques to overlay operational status upon a data center 3D model, allowing the operators to monitor the real-time situation and control the data center from a friendly user interface. This demo highlights: (1)a data center 3D view from a First Person Shooter (FPS) camera, (2)a run-time presentation of visualized infrastructures information. Moreover, to improve the user experience, we employ cutting-edge HCI technologies from multi-touch, for remote access to Cloud3DView. ? 2013 Authors.
Accession Number: 20133616707790
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Record 79 of
Title:Cloud3DView: An interactive tool for cloud data center operations
Author(s):Yin, Jianxiong(1); Sun, Peng(1); Wen, Yonggang(1); Gong, Haigang(2); Liu, Ming(2); Li, Xuelong(3); You, Haipeng(1); Gao, Jinqi(1); Lin, Cynthia(1)
Source: Computer Communication Review Volume: 43 Issue: 4 DOI: 10.1145/2534169.2491704 Published: 2013
Abstract:The emergence of cloud computing has promoted growing demand and rapid deployment of data centers. However, data center operations require a set of sophisticated skills (e.g., command-line-interface), resulting in a high operational cost. In this demo, to reduce the data center operational cost, we design and build a novel cloud data center management system, based on the concept of 3D gamification. In particular, we apply data visualization techniques to overlay operational status upon a data center 3D model, allowing the operators to monitor the real-time situation and control the data center from a friendly user interface. This demo highlights: (1)a data center 3D view from a First Person Shooter (FPS) camera, (2)a run-time presentation of visualized infrastructures information. Moreover, to improve the user experience, we employ cutting-edge HCI technologies from multi-touch, for remote access to Cloud3DView. ? 2013 Authors.
Accession Number: 20140217182468
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Record 80 of
Title:Simulation of the space turntable angular velocity measurement
Author(s):Cui, Kai(1,2); Liu, Zhaohui(2); Li, Zhiguo(2); Yuan, Hui(1,2); Liang, Dongsheng(1,2)
Source: Applied Mechanics and Materials Volume: 246-247 Issue: DOI: 10.4028/www.scientific.net/AMM.246-247.257 Published: 2013
Abstract:For better design and control of the space turntable, a model for measuring its angular velocity was built. The model utilized a two-axis space turntable to perform the simulation basing on the coordinate conversion theory. The measuring simulation went on with the help of MATLAB software using different carrier attitude angles. It shows the maximal error in the sub astral point longitude and/or latitude is 0.00785 degrees when comparing with the STK results, certifying the validity of the models. The satellite attitude angles have influence on the angular velocity, the maximal azimuth angular velocity is 3.784 deg per sec, yet the elevation's is 0.6945 deg per sec when the attitude angles are all 20 degrees. This simulation process provides some guidance for designing, controlling and calibrating the space turntable. ? (2013) Trans Tech Publications, Switzerland.
Accession Number: 20130515973985
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Record 81 of
Title:Generation of three-dimensional optical structures by dynamic holograms displayed on a twisted nematic liquid crystal display
Author(s):Ma, Baiheng(1,2); Yao, Baoli(1); Li, Ze(1,2); Lei, Ming(1); Yan, Shaohui(1); Gao, Peng(1); Dan, Dan(1); Ye, Tong(1)
Source: Applied Physics B: Lasers and Optics Volume: 110 Issue: 4 DOI: 10.1007/s00340-012-5289-x Published: March 1, 2013
Abstract:Reconstruction of computer generated holograms (CGHs) addressed on a spatial light modulator (SLM) is an effective way to dynamically generate designed light field distributions. Based on the classic Gerchberg–Saxton (GS) algorithm, we proposed a technique, which can greatly reduce the computation cost to about 60 % in calculating CGHs for three-dimensional (3D) structures but with little degradation of reconstructed light field compared with the classic GS algorithm. The CGHs calculated by our method were displayed on a twisted nematic liquid crystal display, working as a phase-only-modulation SLM, and 3D structures of optical fields, e.g., 3D array of optical traps and vortices, were reconstructed with high efficiency and high quality. Besides, the possibility for 3D holographic display or projection was also demonstrated with this algorithm by reconstruction several images simultaneously in distinct axial planes. ? Springer-Verlag Berlin Heidelberg 2012.
Accession Number: 20143600039750
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Record 82 of
Title:Design of chirped mirrors used for the dispersion compensation in femtosecond lasers
Author(s):Liao, Chunyan(1,2); Qin, Junjun(1); Hu, Manli(2)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 9068 Issue: DOI: 10.1117/12.2053961 Published: 2013
Abstract:Negative dispersion dielectric multilayer mirrors have contributed significantly to the enhancement of the performance, compactness and reliability of femtosecond lasers. There are two alternative approaches that are widely investigated for dispersion compensation: chirped mirrors and Gires-Tournois mirrors. Chirped mirrors can exhibit a broad smooth highreflectance range if the layer thickness is superimposed a quasi-periodic modulation on a linear variation of the optical thickness of the layers. The performance of such chirped mirrors is calculated and the factors affecting the performance are discussed in detail. In such chirped mirrors, the performance is strongly affected by the expected bandwidth and modulation period of the optical thickness of the layers. ? 2013 SPIE.
Accession Number: 20140217184370
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Record 83 of
Title:Design of RF source based on Direct Digital Synthesizer
Author(s):Liu, Hui(1,2); Qiu, Yuehong(1)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8759 Issue: DOI: 10.1117/12.2014925 Published: 2013
Abstract:A new Radio Frequency (RF) source based on Direct Digital Synthesizer (DDS) is presented in this paper, to improve the performance of the Sound-light tunable filter. A DDS chip called AD9959 is used to produce RF signal. The AD9959 consists of four DDS cores that provide independent frequency, phase, and amplitude control on each channel, and FPGA is used to control AD9959, to ensure a high accurate signal source with multiple signal mode and four channels output is designed. This paper introduces the implementation of system including software and hardware. The test results show that the RF source has 0-200MHz bandwidth and resolution, stability and a series of functions fully realize the scheduled target. ? 2013 SPIE.
Accession Number: 20131516204301
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Record 84 of
Title:Sub-pixel location with phase transfer function for star tracker
Author(s):Xi, Jiangbo(1,2); Song, Zongxi(1); Gao, Wei(1)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8759 Issue: DOI: 10.1117/12.2015091 Published: 2013
Abstract:Star tracker has been widely used as a precise and reliable device for the attitude measuring of a spacecraft. The accuracy of star location will affect the accuracy of star identification and finally the accuracy of attitude measurement. This paper proposed a novel method to locate the star position with the phase transfer function (PTF). The numerical expressions are deduced with the diffraction model of the star point in 1-D and given directly in 2-D. Then calculation is performed and the accuracy is better than 2.1% pixels (SNR=20) with a 3×3 window of airy disk, which is higher than the traditional centroid method. Different sizes of the airy disk from 3 to 6 are simulated with PTF method and we find that the optimal window size is 3 to 5. Finally the Additive Gaussian Noise with SNR from 2 to 40 is introduced to evaluate the novel method and compare it with the traditional centroid method. The accuracy of the new method can reach better than 2.5% pixels and it is much robust than the traditional centroid method, which proves that the method we proposed has a good performance under the noise environment. ? 2013 SPIE.
Accession Number: 20131516204248
