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IEEE International Conference on plasma Science (ICOPS)

作者： Yonhua Tzeng Plasma Processing Laboratory Alabama Microelectronics Science and Technology Center Department of Electrical and Computer Engineering Aubum University Auburn AL USA

Summary form only given. Growth of diamond with extreme physical and chemical properties can be achieved in electrical discharges under properly controlled plasma chemistry at temperatures and pressures where graphite, instead of diamond, is thermodynamically stable. This discovery led us to wide open opportunities for applying the extreme hardness, thermal conductivity, optical and microwave transparency, chemical inertness, wear resistance, coefficient of thermal expansion, dielectric strength, carrier saturation velocities, and many other interesting properties of diamond crystals and coatings to industrial and scientific applications. plasma density, plasma chemistry, as well as physical processes in plasmas such as ion bombardment of substrates and/or the growing diamond surfaces all play important roles in the nucleation and the growth of diamond on various substrates. plasmas generated in gaseous mixtures such as methane and hydrogen with controlled dilution by argon as well as plasmas generated in vapor mixtures formed from properly mixed liquid solutions alone have been developed and optimized for the nucleation and growth of diamond of selected crystal orientations, grain sizes, and doping levels. A systematic experimental project has also been conducted to explore diamond nucleation and growth by plasmas generated in gas mixtures of methane and hydrogen that are highly diluted by more than 90% argon. Growth of well-faceted microcrystalline diamond films with preferred (100) or (111) crystal orientation as well as nanocrystalline diamond films could be tailored by controlling plasma parameters such as microwave power density, gas pressures and compositions, and substrate temperatures.

关键词： plasma applications plasma chemistry Chemical vapor deposition plasma density plasma properties plasma temperature Thermal conductivity Thermal resistance Grain size Ultraviolet sources

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Growth and patterning of aligned carbon nanotubes for applications to cold cathodes and vacuum electronics

Growth and patterning of aligned carbon nanotubes for applic...

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IEEE International Conference on plasma Science (ICOPS)

作者： Yonhua Tzeng Chao Liu Yu-Chun Chen Plasma Processing Laboratory Alabama Microelectronics Science and Technology Centel Department of Electrical and Computer Engineering Aubum University Auburn AL USA

Summary form only given. The extremely large aspect ratio and sharp tips of carbon nanotubes made them among the most promising nanostructures for low-voltage and low-field cold cathode applications. The physically and chemically stable, highly thermally and electrically conductive carbon nanotubes allow very high density of electron current to be emitted without damages to the carbon nanotubes. By properly designing and growing carbon nanotubes and integrating them with 2-D and/or 3-D structures, high performance cold cathodes can be fabricated and applied to various vacuum electronics and vacuum power transferring applications. Well aligned carbon nanotubes have been grown using thermal chemical vapour deposition techniques and patterned into micro-structures by means of photolithographic techniques that are commonly used for silicon integrated circuit fabrication. Electron field emission at an average applied electric field of one volt per micrometer has been achieved. High current density cold cathodes fabricated on micro-patterned substrates as well as 3-D structures were investigated. In this presentation, the growth process, properties of carbon nanotubes, and their applications as cold cathodes for vacuum electronics is discussed.

关键词： Carbon nanotubes Cathodes Carbon dioxide Application software Electron emission Geometry Blades Vacuum technology Chaos plasma applications

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A test-bed for region-based image retrieval using multiple segmentation algorithms and the MPEG-7 eXperimentation model: The schema reference system

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3rd International Conference on Image and Video Retrieval, CIVR 2004

作者： Mezaris, Vasileios Doulaverakis, Haralambos de Otalora, Raul Medina Beltran Herrmann, Stephan Kompatsiaris, Ioannis Strintzis, Michael G. Information Processing Laboratory Electrical and Computer Engineering Department Aristotle University of Thessaloniki Thessaloniki54124 Greece Thessaloniki57001 Greece Institute for Integrated Systems Munich University of Technology MunichD-80290 Germany

ISBN: (纸本)3540225390

The aim of the SCHEMA Network of Excellence is to bring together a critical mass of universities, research centers, industrial partners and end users, in order to design a reference system for contentbased semantic scene analysis, interpretation and understanding. In this paper, recent advances in the development of the SCHEMA reference system are reported, focusing on the application of region-based image retrieval using automatic segmentation. More specifically, the first and the second version of the reference system are presented and the motivation behind the different approaches followed during the development of these two versions is discussed. Experimental results for both systems, using a common collection of images, are shown. Additionally, a comparative evaluation of the two versions both in terms of retrieval accuracy and in terms of time-efficiency is performed, allowing the evaluation of the system as a whole as well as the evaluation of the usability of different components integrated with the reference system, such as the MPEG-7 eXperimentation Model. This illustrates the suitability of the SCHEMA reference system in serving as a test-bed for evaluating and comparing different algorithms and approaches pertaining to the content-based and semantic manipulation of visual information, ranging from segmentation algorithms to indexing features and methodologies. © Springer-Verlag Berlin Heidelberg 2004.

关键词： Semantics

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Enhancement of stents using interference of low-frequency ultrasonic echo signals

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Journal of Medical Ultrasonics 2004年第2期31卷 67-73页

作者： Ohashi, Gosuke Ohya, Akihisa Tobise, Kazimobu Akiyama, Iwaki Faculty of Engineering Shizuoka University Hamamatsu Japan Institute of Information Sciences and Electronics University of Tsukuba Tsukuba Japan Shoryo Electronic Corporation Kamakura Japan Faculty of Engineering Shonan Institute of Technology Fujisawa Japan Image Processing and Vision Research Laboratory Department of Electrical and Computer Engineering University of California at Santa Barbara Santa Barbara CA 93106-9560 United States

Purpose. We set out to enhance the imaging of stents used for coronary coarctation surgery without imaging the reticulation of the stent. Because the stent is a reticulated structure, there is a relation between ultrasound wavelength and the interstice reticulation that produces the echo. Methods. First we performed computer simulation by ultrasound frequency of transmitted signals to analyze this relation. Then, instead of controlling the transmitted wave, we processed the returned signals through a band-pass filter because of the difficulty of controlling the transmitted waves of diagnostic ultrasound equipment. Following this, we conducted experiments on an agar gel phantom containing a stent to verify the effectiveness of this method. Results. The simulation confirmed that the stent was apparent when the ultrasonic wavelength equaled the product of an integer and twice the interval of the reticulation of the stent. Application of a band-pass filter of 0.8 to 1.5MHz to the waveform returned from the agar gel phantom containing the stent. Conclusions. The effectiveness of this method in depicting the stent was confirmed. © The Japan Society of Ultrasonics in Medicine 2004.

关键词： Interference Received waveform Signal processing Stent Ultrasonic echography

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Factorized all-pass IIR adaptive notch filters

Factorized all-pass IIR adaptive notch filters

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International Conference on Acoustics, Speech, and Signal processing (ICASSP)

作者： J.E. Cousseau P.D. Donate Y. Liu Department of Electrical and Computer Engineering Universidad Nacional del Sur Bahia Blanca Argentina Signal Processing Laboratory Helsinki University of Technology Finland

A new family of IIR adaptive notch filters is presented. The family is based on a second-order factorization of the all-pass transfer function that forms the multiple notch filter. These realizations represent an extension of a previous ad-hoc scheme for adaptive notch filtering that avoids a high-order polynomial root finding in order to obtain the unknown frequencies of interest. An interesting aspect related to these novel algorithms is the fact that they introduce a different compromise between bias and SNR if compared with previous realizations available in the literature. Specifically, lower bias than in other approaches for low SNR can be achieved using the new realizations. This property is particularly attractive for multiple sinusoids estimation and tracking. In addition to the algorithm presentation, a discussion of the different properties and characteristics (stationary points, convergence) is included. Also, computer simulations are presented to illustrate the expected performance of the proposed adaptive filters.

关键词： Adaptive filters IIR filters Finite impulse response filter Frequency estimation Polynomials Signal processing algorithms Poles and zeros Bandwidth Adaptive signal processing Laboratories

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Reducing impulsive noise in DSL systems - Robustness and delay

Reducing impulsive noise in DSL systems - Robustness and del...

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Proceedings of the Nordic Signal processing Symposium (NORSIG)

作者： F.H. Gregorio J.E. Cousseau J.L. Figueroa Signal Processing Laboratory Helsinki University of Technology Finland Department of Electrical and Computer Engineering Universidad Nacional del Sur Bahia Blanca Argentina

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Development of digital image retrieval technique using autocorrelogram and wavelet based texture

Development of digital image retrieval technique using autoc...

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Midwest Symposium on Circuits and Systems (MWSCAS)

作者： P. Skulsujirapa S. Aramvith S. Siddhichai Digital Signal Processing Research Laboratory Department of Electrical Engineering Faculty of Engineering Chulalongkom University Bangkok Thailand National Electronics and Computer Technology Center Pathumthani Thailand

In this paper, we present the development of a digital image retrieval technique using autocorrelogram and wavelet based texture feature. Autocorrelogram is a color feature that is able to incorporate the spatial correlation of alike color and is tolerant to large changes in appearance, color, contrast, and brightness. A wavelet transform is used to analyze the textures that are characterized by their energy distribution in each sub-band. We propose an integration of the autocorrelogram and wavelet based texture to improve the performance of the image retrieval system. Experimental results suggest that the proposed integration offers much better performance than using the features separately.

关键词： Digital images Image retrieval Image databases Histograms Spatial databases Wavelet transforms Feature extraction Indexing Content based retrieval Shape

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Silicon-germanium saturable absorber mirrors

Silicon-germanium saturable absorber mirrors

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IEEE Photonics Conference (IPC)

作者： F.J. Grawert S. Akiyama J.T. Gopinath F.O. Ilday J. Liu H. Shen K. Wada L.C. Kimerling E.P. Ippen F.X. Kaertner Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics Massachusetts Institute of Technology Cambridge MA USA Department of Materials Science and Engineering and Material Processing Center Massachusetts Institute of Technology Cambridge MA USA

A silicon-germanium ultra-broadband saturable Bragg reflector with sub-picosecond recovery time is fabricated. Its performance is demonstrated by mode-locking an Er-Yb glass laser generating 220 fs pulses spanning the... 详细信息

关键词： Germanium silicon alloys Silicon germanium Mirrors Optical pulse generation Absorption Laser mode locking Ultrafast optics Optical scattering Pulse measurements Laser feedback

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Integration of 2D and 3D images for enhanced face authentication

Integration of 2D and 3D images for enhanced face authentica...

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International Conference on Automatic Face and Gesture Recognition

作者： F. Tsalakanidou S. Malassiotis M.G. Strintzis Information Processing Laboratory Electrical and Computer Engineering Department Aristotle University of Thessaloniki Thessaloniki Greece Informatics and Telematics Institute Centre for Research and Technology Hellas Thessaloniki Greece

This work presents a complete face authentication system integrating 2D intensity and 3D range data, based on a low-cost, real-time structured light sensor. Novel algorithms are proposed that exploit depth data to achieve robust face detection, localization and authentication under conditions of background clutter, occlusion, face pose alteration and harsh illumination. The well known embedded hidden Markov model technique for face authentication is applied to depth maps. A method for the enrichment of face databases with synthetically generated views depicting various head poses and illumination conditions is proposed. The performance of the proposed system is tested on an extensive face database of 3,000 images. Experimental results demonstrate significant gains resulting from the combined use of depth and intensity.

关键词： Authentication Face detection Lighting Image databases Real time systems Sensor systems Robustness Hidden Markov models Head System testing

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Exploitation of 3D images for face authentication under pose and illumination variations

Exploitation of 3D images for face authentication under pose...

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International Symposium on 3D Data processing Visualization and Transmission

作者： F. Tsalakanidou S. Malassiotis M.G. Strintzis Informatics and Telematics Institute Centre for Research and Technology Hellas Thessaloniki Greece Information Processing Laboratory Electrical and Computer Engineering Department Aristotle University of Thessaloniki Thessaloniki Greece

An appearance-based face authentication system integrating 2D color or intensity images and 3D data is presented. The proposed system is based on a low-cost 3D and color sensor, capable of synchronous real-time acquisition of 3D images and associated color images. Novel algorithms are proposed that exploit depth information and prior knowledge of face geometry and symmetry to achieve robust face detection, localization and authentication under conditions of background clutter, occlusion, face pose alteration and harsh illumination. A method for the enrichment of face databases with synthetically generated views depicting variations in pose and illumination is proposed to cope with head rotations and illumination variations, avoiding a cumbersome enrolment process. The performance of the proposed authentication scheme is tested thoroughly on a face database of 1500 images, recorded with the 3D acquisition system. Experimental results demonstrate significant gains resulting from the combined use of depth and color or intensity information, in comparison to the use of 2D images alone.

关键词： Authentication Lighting Face detection Image databases Image sensors Sensor systems Real time systems Color Information geometry Robustness

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