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Biocompatibility of polyimide microelec.rode array for retinal stimulation

Materials science and engineering C 2004年第1-2期24卷 185-189页

作者： Seo, Jong-Mo Kim, Sung June Chung, Hum Kim, Eui Tae Yu, Hyeong Gon Yu, Young Suk Department of Ophthalmology Seoul Natl. Univ. Coll. of Med. Seoul Natl.Univ.Hospital Clin.Res. Seoul 110-744 Korea Republic of Nano Bioelectronics/Syst. Res. Ctr. Seoul National University Seoul 151-742 Korea Republic of Sch. of Elec. Eng./Computer Science Seoul National University Seoul 151-742 Korea Republic of

Artificial retina is aimed for the stimulation of remained retinal neurons in the patient with degenerated photoreceptors. Microelec.rode arrays have been developed for this as a part of stimulator. To minimize the damage during ophthalmic surgery and to get better contact to retina, flexible polyimide, which can be fabricated based on semiconductor manufacturing, was selec.ed as the substrate material. In vitro biocompatibility of polyimide microelec.rode array (MEA) was tested by co-culture with human retinal pigment epithelial cells (RPE). In vivo biocompatibility was tested in the rabbit eyes. The polyimide MEA showed good affinity to human RPE and did no harmful effect. It also showed very good stability and safety in rabbit eyes by 12 weeks. © 2003 Elsevier B.V. All rights reserved.

关键词： Microelec.rodes

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Robust cross-directional control of paper making machines with saturating actuators

Robust cross-directional control of paper making machines wi...

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Control Systems 2004 Conference, Preprints

作者： Akkermans, J.A.G. Wills, A.G. Heath, W.P. Department of Electrical Engineering Eindhoven University of Technology PO Box 513 5600 MB Eindhoven Netherlands Sch. of Elec. Eng. and Comp. Science University of Newcastle NSW 2308 Australia Control Systems Centre UMIST PO Box 88 Manchester M60 1QD United Kingdom

We discuss the design of cross-directional controllers which are guaranteed to be robustly stabilizing while incorporating a quadratic program for steady state performance. In particular we propose implementing cross-directional controllers in modal form with a constrained internal model control structure. Nominal optimal steady state performance is guaranteed via a non-linear element that incorporates a quadratic program. The quadratic program can be expressed as a continuous sector bounded nonlinearity together with two linear transformations. Thus the multivariable circle criterion can be used to guarantee closed-loop stability in the presence of disturbances and modeling uncertainties.

关键词： Papermaking machinery

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Equatorial spread F irregularity characteristics over São Luís, Brazil, using VHF radar and GPS scintillation techniques

Equatorial spread F irregularity characteristics over São L...

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作者： Rodrigues, F.S. De Paula, E.R. Abdu, M.A. Jardim, A.C. Iyer, K.N. Kintner, P.M. Hysell, D.L. Inst. Nac. de Pesq. Espaciais DAE S. Jose dos Campos Sao Paulo Brazil Department of Earth Science Cornell University Ithaca NY United States Department of Physics Saurashtra University Rajkot-Gujarat India Sch. of Elec./Computer Engineering Cornell University Ithaca NY United States Aeronomy Division Inst. Natl. de Pesquisas Espaciais Av. dos Astronautas 1758 CP 515 Sao Jose dos Campos-SP Brazil Earth Science Department Cornell University 2108 Snee Hall Ithaca NY 14853-3801 United States India Sch. of Elec./Computer Engineering Cornell University 302 Rhodes Hall Ithaca NY 14853-3801 United States Earth Science Department Cornell University 2122 Snee Hall Ithaca NY 14853 United States

Multitechnique observations may considerably improve our understanding of factors responsible for the generation, growth, and dynamics of the destabilized nighttime equatorial F region plasma irregularities. In order to investigate the dynamics of plasma density irregularities of different scale sizes, a campaign of observations was conducted during 11-20 November 2001 at the Brazilian magnetic equatorial station São Luís (2.57°S, 44.21°W, dip latitude 1.73°S). We carried out observations using VHF coherent backscatter radar, two spaced GPS-based scintillation monitors, and one digisonde. Range type spread F on ionograms and radar plume signatures on range-time-intensity maps of the VHF radar started at similar times. In order to compare GPS L1 (1.575 GHz) scintillations and radar plumes we used the scintillation S4 index computed for the signal transmitted by the highest elevation satellite. GPS scintillations were not observed during the initial bottom-type layer shown by the radar;however, stronger scintillations (higher S4 values) were observed concurrently to stronger radar echoes. Although the time duration of GPS scintillation is longer than the duration of the plumes observed by the radar, ionosonde spread F is still much longer than scintillation occurrence, confirming that smaller scale-size irregularities decay faster. Zonal and vertical velocities of 5-m irregularities measured by the radar were analyzed jointly with the apparent zonal velocity of ∼400-m irregularities measured by the spaced-receiver scintillation method. Larger values of the zonal velocity measured by the scintillation technique were found during the explosive growth phase of radar plumes associated with large values of vertical drifts measured by the radar.

关键词： Global positioning system

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Transmission of multiple wireless standards over a radio-over-fiber network

Transmission of multiple wireless standards over a radio-ove...

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2004 IEEE MITT-S International Microwave Symposium Digest

作者： Tang, P.K. Ong, L.C. Luo, B. Alphones, A. Fujise, M. Department of Electrical Engineering National University of Singapore Singapore Singapore Institute for Infocomm Research Singapore Science Park II S117674 Singapore Sch. of Elec. and Electron. Eng. Nanyang Technological University S639798 Singapore Communications Research Laboratory 3-4 Hikarino-oka Yokosuka 239-0847 Japan

ISBN: (纸本)0780383311

This paper investigates the optical transmission characteristics of an optical signal as it is modulated by a RF signal in an elec.ro-absorption modulator (EAM). The transmission characteristics of the radio-over-fiber (ROF) system were evaluated at cellular bands of 900MHz, 1.8GHz, 1.9GHz, 2.1GHz and the ISM bands of 2.4GHz and 5.8GHz for wireless local area network (WLAN) and intelligent transport systems (ITS} applications. Error Vector Magnitude (EVM) and packet error rate (PER) measurements were carried out to evaluate the performance.

关键词： Radio transmission

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An experience with the neural network for auto-landing system of an aircraft

An experience with the neural network for auto-landing syste...

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ICEIS 2004 - Proceedings of the Sixth International Conference on Enterprise Information Systems

作者： Anavatti, Sreenatha G. Young, Choi J. Pisch.ry, Francois School of Aerospace Civil and Mechanical Engineering Univ. of New South Wales at ADFA Canberra Australia Sch. of Elec. Eng. and Comp. Science Seoul National University Seoul Korea Republic of Laboratoire d'Automatique Indust. Inst. Natl. Des Sci. Appl. de Lyon Villeurbanne France

ISBN: (纸本)9728865007

Generalization by the Neural Networks is an added advantage that can provide very good robustness and disturbance rejection properties. By providing a sufficient number of training samples (inputs and their corresponding outputs), a network can deal with some inputs it has never seen before. This ability makes them very interesting for control applications because not only they can learn complicated control junctions but they are able to respond to changing or unexpected environments. Aircraft landing system provides one such scenario wherein the flight conditions change quite dramatically over the path of descent. The present work discusses the training of a neural network to imitate a robust controller for auto-landing of an aircraft. The comparisons with the robust controller indicate the additional advantages of the neural network.

关键词： Neural networks

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Applications of advanced indentation technique to pre-qualification and periodic monitoring of strength performance of industrial structures

Applications of advanced indentation technique to pre-qualif...

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Proceedings of the 11th Asian Pacific Conference on Nondestructive Testing

作者： Choi, Yeol Jang, Jae-Il Kim, Kwang-Ho Kwon, Dongil Park, Sang-Ki Frontics Inc. Res. Institute of Advanced Materials Seoul National University Seoul 151-742 Korea Republic of Sch. of Mat. Science and Engineering Seoul National University Seoul 151-742 Korea Republic of Power Generation Research Lab. Korea Elec. Power Research Institute Daejon 305-380 Korea Republic of

The demand for new in-field technology which can non-destructively evaluate the key material properties has been increased for safe and economic operations of industrial structures/facilities whose material properties can be significantly degraded during operation in hostile environments. As a promising method to meet the needs, an advanced indentation technique is suggested here. This novel technique can evaluate the true-stress-true-strain relationship and quantitative tensile properties (such as yield strength, tensile strength and work-hardening exponent) non-destructively by analyzing indentation load-depth curve. In this paper, two recent applications of the indentation technique to pre- and in-service-inspection (PSI and ISI) of industrial structures are introduced and discussed. First, pre-qualification of strength performance of welded joint in power plant pipes is successfully performed using this indentation technique while conventional pre-qualification of welded joints through other non-destructive techniques are just focusing on exact crack detection. Second, it was proved that the advanced indentation technique has the strong potential to be used for in-field periodic monitoring of strength change of oil/gas transmission pipeline, which is required by new regulations for safe maintenance and economical repair.

关键词： Materials science

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On robust ∞ filter design for uncertain neural systems: LMI optimization approach

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Applied Mathematics and Computation (New York) 2004年第3期159卷 625-639页

作者： Park, Ju H. Kwon, O. Lee, S. Won, S. Sch. of Elec. Eng./Computer Science Yeungnam University 214-1 Dae-Dong Kyongsan 712-749 Korea Republic of Department of Electrical Engineering Pohang Univ. of Sci. and Technology San 31 Hyoja-dong Pohang 790-784 Korea Republic of

This article deals with the robust ∞ filtering problem for neutral delay differential systems with parametric uncertainties. A linear matrix inequality (LMI) approach is proposed to design the robust ∞ filter such that the filtering system remains asymptotically stable and the bound of ∞ norm is minimized. The Lyapunov stability theory is used for analysis of the system. A numerical example is provided to illustrate the validity of proposed design approach. © 2003 Elsevier Inc. All rights reserved.

关键词： Robustness (control systems)

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View Space Representation and Viewpoint Planning Computation for Automatic 3D Object Modeling

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Systems and computers in Japan 2004年第4期35卷 60-71页

作者： Morooka, Ken'ichi Zha, Hongbin Hasegawa, Tsutomu Grad. Sch. of Sci. and Engineering Tokyo Institute of Technology Yokohama 226-8503 Japan Center for Information Science Peking University Beijing 100871 China Grad. Sch. of Info. Sci./Elec. Eng. Kyushu University Fukuoka 812-8581 Japan

Viewpoint planning plays an important role in automatic 3D model generation. We have proposed an optimal viewpoint planning [9] for the purpose of model generation by merging images acquired from multiple viewpoints on a sphere that encircles object. This method uses a discretized approximate sphere which involves problems of sphere tessellation and of sphere representation. One must consider that the scanned surface of an object is projected onto a sphere, and that the computational cost increases directly with the number of images. However, there are no appropriate sphere representation methods available. This paper proposes a new representation method based on a 2D array, and develops a new viewpoint planning algorithm. The proposed system is verified by algorithmic analysis and experiments using a real modeling system. © 2004 Wiley Periodicals, Inc.

关键词： Information science

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Bitumen emulsions in road construction - A review

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Road and Transport Research 2004年第1期13卷 25-38页

作者： Gorman, Jacinta L. Crawford, Russell J. Harding, Ian H. URS Australia Dispersion Science Environment and Biotechnology Centre School of Engineering and Science Environment and Biotechnology Centre Sch. of Biophys. Sci./Elec. Eng. Swinburne University of Technology P.O. Box 218 Hawthorn Vic. 3122 Australia

The most common way in which bitumen is applied to mineral aggregate substrates in road making processes is in the form of a so-called 'bitumen emulsion'. Bitumen emulsions are a dispersion of bitumen in an aqueous continuous phase, stabilised by the addition of an emulsifier. They are usually prepared as genuine emulsions at high temperatures, but applied as solid dispersions at ambient temperatures. During road making, these emulsions (or dispersions) must break over the surface of a range of mineral aggregates in a controlled manner, and hence a thorough understanding of the physicochemical properties of such emulsions, and the aggregate substrates, is required. This paper presents a summary of global industry processes for preparing bitumen emulsions (including a review of commonly used emulsifiers), and discusses the factors that can affect the characteristics and behaviour of these emulsions with particular reference to their application to mineral aggregates.

关键词： Road construction

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Connections between H2 optimal filters and unknown input observers - Performance limitations of H2 optimal filtering

Connections between H2 optimal filters and unknown input obs...

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Proceedings of the 2004 American Control Conference (AAC)

作者： Saberi, Ali Stoorvogel, Anton A. Sannuti, Peddapullaiah Sch. of Elec. Eng. and Comp. Science Washington State University Pullman WA 99164-2752 United States Dept. of Mathematics Eindhoven Univ. of Technology P.O. Box 513 5600 MB Eindhoven Netherlands Department of Electrical Engineering Delft Univ. of Technology P.O. Box 5031 2600 GA Delft Netherlands Dept. of Electrical Engineering Rutgers University 94 Brett Road Piscataway NJ United States

This paper establishes a connection between the unknown input observer problem (also known as the exact input-decoupling filtering problem) and the Kalman filtering problem. Such a connection leads to a better understanding of filtering. As a consequence of this, tools for the analysis as well as synthesis of filters can be developed. Moreover, such tools can be utilized to establish performance limitations of Kalman filtering as related to the structural properties of the given system.

关键词： Kalman filtering

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