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41.
Rodrigo F. P. Martins Arman Ahnood Nuno Correia Luís M. N. P. Pereira Raquel Barros Pedro M. C. B. Barquinha Ricardo Costa Isabel M. M. Ferreira Arokia Nathan Elvira E. M. C. Fortunato 《Advanced functional materials》2013,23(17):2153-2161
The ability to process and dimensionally scale field‐effect transistors with and on paper and to integrate them as a core component for low‐power‐consumption analog and digital circuits is demonstrated. Low‐temperature‐processed p‐ and n‐channel integrated oxide thin‐film transistors in the complementary metal oxide semiconductor (CMOS) inverter architecture are seamlessly layered on mechanically flexible, low‐cost, recyclable paper substrates. The possibility of building these circuits using low‐temperature processes opens the door to new applications ranging from smart labels and sensors on clothing and packaging to electronic displays printed on paper pages for use in newspapers, magazines, books, signs, and advertising billboards. Because the CMOS circuits reported constitute fundamental building blocks for analog and digital electronics, this development creates the potential to have flexible form factor computers seamlessly layered onto paper. The holistic approach of merging low‐power circuitry with a recyclable substrate is an important step towards greener electronics. 相似文献
42.
Ricardo Carelli Guillermo Forte Luis Canali Vicente Mut Gastn Aragus Eduardo Destfanis 《Mechatronics》2008,18(4):187-194
The present work proposes an autonomous tracking control system and a control structure to combine autonomous and teleoperation commands in a bicycle-type mobile robot. This compounded operation renders great flexibility to the control system of the mobile robot. For autonomous operation, a simple tracking controller that includes compensation of the robot dynamics is developed. This tracking control system is proved to be stable in the sense that it asymptotically reaches the tracking objective. Teleoperation with visual access to the robot’s workspace is integrated via a joystick with the autonomous operation of the robot. Simulations and experimental results on a prototype robot show the feasibility and performance of the proposed control system. 相似文献
43.
Thanh‐Dinh Nguyen Bernardo U. Peres Ricardo M. Carvalho Mark J. MacLachlan 《Advanced functional materials》2016,26(17):2875-2881
Iridescence in animals and plants often arises from structural coloration, which involves hierarchical organization of minerals and biopolymers over length scales of the visible spectrum, leading to diffraction of light. In this work, discarded crustacean shells that are not known for their structural colors are used to produce photonic nanostructures of large, freestanding chiral nematic mesoporous chitosan membranes with tunable iridescent color. Bioinspired by colorful nanostructures in nature, photonic hydrogels with Bouligand‐type organization are fabricated from the twisted mesoporous membranes, where the chitosan nanofibrils are a novel precursor for surface acetylation and are also a biotemplate for polymerizing methyl methacrylate. The colors of the hydrogels can be tailored by swelling as they show large volume changes in response to changes in solvent environment. 相似文献
44.
Micael S. Couceiro Rui P. Rocha N. M. Fonseca Ferreira J. A. Tenreiro Machado 《Signal, Image and Video Processing》2012,6(3):343-350
One of the most well-known bio-inspired algorithms used in optimization problems is the particle swarm optimization (PSO), which basically consists on a machine-learning technique loosely inspired by birds flocking in search of food. More specifically, it consists of a number of particles that collectively move on the search space in search of the global optimum. The Darwinian particle swarm optimization (DPSO) is an evolutionary algorithm that extends the PSO using natural selection, or survival of the fittest, to enhance the ability to escape from local optima. This paper firstly presents a survey on PSO algorithms mainly focusing on the DPSO. Afterward, a method for controlling the convergence rate of the DPSO using fractional calculus (FC) concepts is proposed. The fractional-order optimization algorithm, denoted as FO-DPSO, is tested using several well-known functions, and the relationship between the fractional-order velocity and the convergence of the algorithm is observed. Moreover, experimental results show that the FO-DPSO significantly outperforms the previously presented FO-PSO. 相似文献
45.
Energy management system (EMS) computer architectures have changed significantly over the recent past increasing the difficulty and the need for a priori assessment of system performance and dependability. The old practice based on measurements is no longer acceptable because of the flexibility accrued with the deployment of the new distributed computer-based systems. The number of “what if” questions increased since EMS systems are now implemented using multiple workstations that can be interconnected in various different ways.In this paper we show how alternative configurations can be modeled and analyzed, before proposing and purchasing any equipment, with the assistance of Markov reward models. We review the concept of Markov reward models and show how they can be applied in the availability analysis of SCADA/EMS computer systems. The paper also presents a software tool that facilitates automatic generation and solution of large Markov reward models. The input language of this modeling tool uses a variation of stochastic Petri nets called stochastic reward nets, which are also reviewed. We believe this is the first time a detailed quantitative model of a SCADA/EMS computer system is proposed and solved in the general literature. 相似文献
46.
There are at least two procedures for setting the tolls paid by power line users. One consists of regulating them in a standard process. The other, which is used in Argentina, involves auctioning the lines to the lowest toll. In this paper we show that an auction yields higher expected social welfare if n ≥ 2 bid. Expected social welfare is even higher if, as in Argentina, those who benefit from the line can also bid and build. Moreover, when the social welfare is utilitarian, an auction beats regulation even when the regulator can perfectly audit costs ex post.We describe and examine the auction of the fourth Comahue transmission line in Argentina. Assuming that the regulator's information about costs is similar to the information held by the industry, the model suggests that had tolls been regulated, they would have been at least 61% higher. 相似文献
47.
Isaac Seoane Gerson Rodríguez de los Santos José Alberto Hernández Manuel Urueña Ricardo Romeral Ángel Cuevas David Larrabeiti 《Photonic Network Communications》2011,21(3):278-287
In Tunable-Transmitter Fixed-Receiver (TT-FR)-based Wavelength Division Multiplexed (WDM) ring topologies, each node is provided
with a dedicated wavelength (home channel) for reception, which must be shared by the upstream nodes willing to communicate
with it. Thus, to avoid channel collisions, it is necessary to define a Medium Access Control (MAC) mechanism that arbitrates
access to a given destination wavelength. This work proposes and analyses a simple MAC mechanism that avoids channel collisions
by recirculating traffic on the upstream ring segment where congestion was detected. Essentially, whenever a given node has
got any traffic to transmit, it must first block access to in-transit traffic, which is reflected back to the upstream node
over a second optical fibre. Such blocked traffic is given a second chance to pass through the congested node after a round
segment delay, thus making use of the ring topology as buffering units. This work analyses the performance operation of such
a MAC protocol under two policies applied to recirculated traffic: (1) recirculation bypass and (2) recirculation store-and-forward. 相似文献
48.
Ricardo A. Aroca C. Andre T. Salama 《Analog Integrated Circuits and Signal Processing》2006,48(3):167-174
This paper presents the design and implementation of a new wide dynamic range parallel feedback (PF) transimpedance amplifier
(TIA) for 10 Gb/s optical links. The wide dynamic range is attributed to the novel TIA architecture employing both shunt-shunt
and shunt-series feedback networks. The outstanding features of the TIA are wide dynamic range, high gain, low power consumption
and design simplicity. A prototype implemented in a 0.5 μm SiGe BiCMOS technology and operating at −3.3 V power supply features
an 18.4 dBm dynamic range with a BER less than 10−12, an optical sensitivity of −16 dBm, optical overload of +2.4 dBm, a bandwidth of 8.27 GHz, a gain of 950 Ω and a power consumption
of 189 mW. The new parallel feedback architecture offers improved overload and noise performance when compared to previously
reported, state of the art, single feedback TIA designs and meets all the 10 Gigabit Ethernet and short-reach OC-192 SONET
specifications.
Ricardo Andres Aroca received the B.S. (Hons) degree in electrical engineering from the University of Windsor, Canada, and the M.S. degree from
the University of Toronto, Canada, in 2001 and 2004, respectively. In 2000 he spent two 4 month internships with Nortel Networks
in the Microelectronics Department. Mr. Aroca received the Natural Sciences and Engineering Research Counsel of Canada (NSERC)
Postgraduate Scholarship award in 2002. He is currently working toward the Ph.D. degree at the University of Toronto where
his research interests lie in the area of high-frequency integrated circuits for wireless and wireline communication systems.
C. Andre T. Salama received the B.A.Sc. (Hons.) M.A.Sc. and Ph. D. degrees, all in Electrical Engineering, from the University of British Columbia
in 1961, 1962 and 1966 respectively. From 1962 to 1963 he served as a Research Assistant at the University of California,
Berkeley. From 1966 to 1967 he was employed at Bell Northern Research, Ottawa, as a Member of Scientific Staff working in
the area of integrated circuit design. Since 1967 he has been on the staff of the Department of Electrical and Computer Engineering,
University of Toronto where he held the J.M. Ham Chair in Microelectronics from 1987 to 1997. In 1992, he was appointed to
his present position of University Professor for scholarly achievements and preeminence in the field of microelectronics.
In 1989-90, he was awarded the ITAC/NSERC Research Fellowship in information technology. In 1994, he was awarded the Canada
Council I.W. Killam Memorial Prize in Engineering for outstanding career contributions to the field of microelectronics. In
2000, he received the IEEE Millenium Medal. In 2003, he received the Outstanding Lifetime Achievement Award from the Canadian
Semiconductor Technology Conference for seminal and outstanding contributions to semiconductor device research and promotion
of Canadian University research in microelectronics. In 2004, he received the NSERC Lifetime Achievement Award of Research
Excellence for outstanding and sustained contributions to the field of microelectronics and the Networks of Centres of Excellence
(NCE) Recognition Award for research excellence and outstanding leadership.He was associate editor of the IEEE Transactions
on Circuits and Systems in 1986–88 and a member of the International Electron Devices Meeting (IEDM) Technical Program Committeein
1980–82, 1987–89 and 1996–98. He was the chair of the Solid State Devices Subcommittee for IEDM in 1998 and was a member of
the editorial board of Solid State Electronics from 1984 to 2002. He is presently a member of the editorial board of the Analog
IC and Signal Processing Journal and the Technical Program Committee of the International Symposium on Power Semiconductor
Devices and ICs (ISPSD) and the Technical ProgramCommittee of the International Symposium on Low Power Electronics and Design
(ISLPED). He chaired the technical program committee of ISPSD in 1996 and was the general chair for the conference in 1999.Dr.
Salama is the Scientific Director of Micronet, a network of centres of excellence focussing on microelectronics research and
funded by the Canadian Government and Industry. He has published extensively in technical journals, is the holder of eleven
patents and has served as a consultant to the semiconductor industry in Canada and the U.S. His research interests include
the design and fabrication of semiconductor devices and integrated circuits with emphasis on deep submicron devices as well
as circuits and systems for high speed, low power signal processing applications. Dr. Salama is a Fellow of the Institute
of Electrical and Electronics Engineers, a Fellow of the Royal Society of Canada, a Fellow of the Canadian Academy of Engineering,
a member of the Association of Professional Engineers of Ontario, the Electrochemical Society and the Innovation Management
Association of Canada. 相似文献
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