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作者： Han, M. Snyder, J.E. Tang, W. Lograsso, T.A. Schlagel, D.L. Jiles, D.C. Materials and Engineering Physics Program Ames Laboratory Iowa State University Ames IA 50011 United States Department of Materials Science and Engineering Iowa State University Ames IA 50011 United States Department of Electrical and Computer Engineering Iowa State University Ames Iowa 50011 United States

The Tb5 (Six Ge4-x) alloy system has many features in common with the Gd5 (Six Ge4-x) system although it has a more complex magnetic and structural phase diagram. This paper reports on the magnetic anisotropy and magnetic phase transition of single-crystal Tb5 (Si2.2 Ge1.8) which has been investigated by the measurements of M-H and M-T along the a, b, and c axes. The variation of 1/χ vs T indicates that there is a transition from paramagnetic to ferromagnetic at Tc =110 K. Below this transition temperature M-H curves show very strong anisotropy, and it is believed that this is due to the complex spin configuration. M-H measurements at T=110 K show that the a axis is the easy axis, and that the saturation magnetization is 200 emug. The b axis is the hard axis, which needs an external magnetic field much higher than 2 T to saturate the magnetization in that direction, indicating a high magnetocrystalline anisotropy. The c axis is of intermediate hardness. The magnetic properties of this material are therefore very different from those of the related Gd5 Si2 Ge2 system, in which the b axis was found to be the easy axis and the magnitude of the anisotropy was smaller. © 2005 American Institute of Physics.

关键词： Magnetic fields

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Handling missing attribute values in preterm birth data sets

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10th International Conference on Rough Sets, Fuzzy Sets, Data Mining, and Granular Computing, RSFDGrC 2005

作者： Grzymala-Busse, Jerzy W. Goodwin, Linda K. Grzymala-Busse, Witold J. Zheng, Xinqun Department of Electrical Engineering and Computer Science University of Kansas Lawrence KS 66045 United States Institute of Computer Science Polish Academy of Sciences 01-237 Warsaw Poland Nursing Informatics Program Duke University Durham NC 27710 United States Filterlogix Lawrence KS 66049 United States

ISBN: (纸本)3540286608

The objective of our research was to find the best approach to handle missing attribute values in data sets describing preterm birth provided by the Duke University. Five strategies were used for filling in missing attribute values, based on most common values and closest fit for symbolic attributes, averages for numerical attributes, and a special approach to induce only certain rules from specified information using the MLEM2 approach. The final conclusion is that the best strategy was to use the global most common method for symbolic attributes and the global average method for numerical attributes. © Springer-Verlag Berlin Heidelberg 2005.

关键词： Data handling

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Synthesis and luminescence properties of novel ZnO nanostructures: micro and nanospheres, polyhedral cages, tetra-pods, needles, tipped nanorods, nanowires and other “microphone–shaped” structures

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MRS Online Proceedings Library 2005年第1期900卷 1-6页

作者： Aurangzeb Khan Wojciech M. Jadwisienczak Martin E Kordesch Department of Physics and Astronomy and CMSS Program Ohio University Athens USA School of Electrical Engineering and Computer Science Ohio University Athens USA

Novel ZnO nanostructures such as hollow nanospheres, nano-cages, nanoneedles, tetra-pods, nanowires, aligned nanorods and nanotubes are synthesized via thermal evaporation of ZnO and graphite powder mixtures in reduced oxygen atmosphere in the presence of argon and nitrogen flows. The ZnO nanostructures, especially nanospheres, have a unique shape and are hollow inside with walls densely decorated with aligned nanowires. Photoluminescence of synthesized ZnO structures measured at 300 K exhibits a strong near band edge peak at ∼380 nm and deep level green band centered at ∼550 nm. Fabricated ZnO structures can be studied for various applications in optoelectronics and sensors.

关键词： nanostructure luminescence semiconducting

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Reduced-order model-based feedback controller design for subsonic cavity flows

Reduced-order model-based feedback controller design for sub...

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43rd AIAA Aerospace sciences Meeting and Exhibit

作者： Yuan, X. Caraballo, E. Yan, P. Özbay, H. Serrani, A. DeBonis, J. Myatt, J.H. Samimy, M. Collaborative Center of Control Science Ohio State University United States Department of Electrical and Computer Engineering Department of Mechanical Engineering United States Bilkent Univ. Dept. of Electrical and Electronics Eng. Ankara Turkey NASA Glenn's Quiet Aircraft Technology Program United States Air Force Research Laboratory Air Vehicles Directorate WPAFB United States

This paper explores feedback controller design for cavity flows based on reduced-order models derived using Proper Orthogonal Decomposition (POD) along with Galerkin projection method. Our preliminary analysis shows that the equilibrium of the POD model is unstable and a static output feedback controller cannot stabilize it. We develop Linear Quadratic (LQ) optimal state feedback controllers and LQ optimal observers for the linearized models. The linear controllers and observers are applied to the nonlinear system using simulations. The controller robustness is numerically tested with respect to different POD models generated at different forcing frequencies. An estimation for the region of attraction of the linear controllers is also provided.

关键词： Subsonic flow

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Transistor characteristics of thermal chemical vapor deposition carbon nanotubes field emission triode

Journal of Vacuum Science & Technology B: Microelectronics a...

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Journal of Vacuum science & Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena 2005年第2期23卷 868-873页

作者： Y. M. Wong W. P. Kang J. L. Davidson W. Hofmeister S. Wei J. H. Huang Department of Electrical Engineering and Computer Science Vanderbilt University Nashville Tennessee 37235 Interdisciplinary Graduate Program in Material Science Vanderbilt University Nashville Tennessee 37235 Department of Materials Science and Engineering National Tsing Hua University Hsinchu 300 Taiwan Republic of China

A study of thermal chemical vapor deposition (CVD) grown carbon nanotubes (CNTs) field emitters in a triode amplifier configuration is reported. The CNT transistor characteristics were examined by integrating gate and anode with CNT cathode in two structural forms, utilizing a TEM grid (transmission electron microscope specimen holder) as the gate electrode and a micropatterned CNT with self-aligned gate. The TEM-grid CNT triode displayed clearly gate-controlled current modulation behavior with distinct cutoff, linear, and saturation regions, and a reasonable gate turn-on field of ∼5.4V∕μm despite a large cathode-gate spacing of ∼120μm . The field emission result established the basic transistor characteristics of CNTs in a triode configuration. A CNT triode construct with a self-aligned gated fabrication technique was also developed to realize a monolithic triode structure with shorter gate-cathode spacing, lowering gate voltage, and enhancing emission current. The triode exhibited a significantly lower gate turn-on voltage of ∼40V , and gate-controlled modulation of the emission current. An anode current density of ∼30mA∕cm2 was achieved at a gate voltage of ∼80V and an anode voltage of ∼200V . The dc characteristics for both of the CNT triodes were investigated, including Ia versus Va for different Vg . Moreover, dc parameters such as transconductance, amplification factors, and anode resistance of the triode amplifier were determined. The CNT triodes exhibited useful amplification factor and high output impedance.

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Incomplete inverse preconditioners

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ARI Bulletin of the Istanbul Technical University 2005年第3期54卷 48-64页

作者： Alvarado, Fernando Dag, Hasan Department of Electrical and Computer Engineering University of Wisconsin Madison 53706 United States Computational Science and Engineering Program Informatics Institute Istanbul Technical University 34469 Maslak Istanbul Turkey

Incomplete LU factorization is a valuable preconditioning approach for sparse iterative solvers. An "ideal" but inefficient preconditioner for the iterative solution of Ax = b is A-1 itself. This paper describes a preconditioner based on sparse approximations to partitioned representations of A-1, in addition to the results of implementation of the proposed method in a shared memory parallel environment. The partitioned inverses are normally somewhat sparse. Their sparsity can be enhanced with suitable ordering and partitioning algorithms. Sparse approximations to these partitioned inverse representations can be obtained either by discarding selected nonzero entries of these inverses or by precluding the creation of some inversion fills. Experimental results indicate that the use of these partitioned incomplete inverses as preconditioners results in excellent highly parallel preconditioners.

关键词： Conjugate gradient Iterative methods Parallel computation Partitioned inverse method Preconditioner

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Integrated biological-semiconductor devices

Integrated biological-semiconductor devices

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作者： Stroscio, Michael A. Dutta, Mitra IEEE United States University of Illinois Chicago IL 60607 United States Department of Bioengineering United States Department of Electrical and Computer Engineering United States Department of Physics University of Illinois Chicago United States American Association for the Advancement of Science United States American Physical Society Yale Science and Engineering Association United States Army Research Laboratory United States Optical Society of America United States Society of Women Engineers Army Research Laboratory United States

The advent of semiconductor devices with nanoscale dimensions creates the potential to integrate nanoelectronics and optoelectronic devices with a great variety of biological systems. Moreover, the advances in nanotechnology are opening the way to achieving direct electrical contact of nanoelectronic structures with electrically and electrochemically active subcellular structures - including ion channels, receptors, and transmembrane proteins such as bacteriorhodopsin. Direct electrical interfacing at the biomolecular level opens the possibility of monitoring and controlling critical biological functions and processes in unprecedented ways, and portends a vast array of possibilities such as new classes of prosthetic devices, medical monitoring devices, medical delivery systems, and patient monitoring systems, as well as other applications. This article describes the salient properties of relevant biological structures and nanostructures. Advances in integrating man-made nanostructures with biological structures, including biomolecules, are described as well as the properties, characteristics, and functions of integrated nanoelectronic- biological structures. Future directions based on these prototype systems are highlighted. © 2005 IEEE.

关键词： Semiconductor devices

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Vertically aligned carbon nanotubes field emission devices fabricated by furnace thermal CVD at atmospheric pressure

Vertically aligned carbon nanotubes field emission devices f...

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International Conference on Vacuum Nanoelectronics (IVNC)

作者： S. Wei W.P. Kang J.L. Davidson W.H. Hofmeister B.K. Choi J.H. Huang Program in Materials Science Vanderbilt University Nashville TN USA Department of Electrical Engineering and Computer Science Vanderbilt University Nashville TN USA Department of Materials Science and Engineering National Tsing Hua University Hsinchu Taiwan

In this paper, vertically aligned carbon nanotubes field emission devices were fabricated from the as grown carbon nanotubes (CNTs) by furnace thermal CVD at atmospheric pressure. The device was tested in vacuum (/spl sim/10/sup -6/ torr) for field emission characterization. The turn-on field was about 3 V//spl mu/m, which is comparable to data reported elsewhere.

关键词： Carbon nanotubes Furnaces Temperature Raman scattering Chemical vapor deposition Cathodes Diodes Morphology Scanning electron microscopy Spectroscopy

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A comparative evaluation of competitive learning algorithms for edge detection enhancement

A comparative evaluation of competitive learning algorithms ...

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European Signal Processing Conference (EUSIPCO)

作者： Tuba Sirin Mehmet Izzet Saglam Isin Erer Muhittin Gokmen Okan Ersoy Informatics Institute Computer Science and Engineering Informatics Institute Satellite Communication and Remote Sensing Program Faculty of Electrical and Electronic Engineering Electronics and Communication Department Faculty of Electrical and Electronic Engineering Istanbul Technical University Maslak Istanbul TURKEY Purdue University School of Electrical and Computer Engineering West Lafayette Indiana USA

Most edge detection algorithms include three main stages: smoothing, differentiation, and labeling. In this paper, we evaluate the performance of algorithms in which competitive learning is applied first to enhance edges, followed by an edge detector to locate the edges. In this way, more detailed and relatively more unbroken edges can be found as compared to the results when an edge detector is applied alone. The algorithms compared are K-Means, SOM and SOGR for clustering, and Canny and GED for edge detection. Perceptionally, best results were obtained with the GED-SOGR algorithm. The SOGR is also considerably simpler and faster than the SOM algorithm.

关键词： Image edge detection Image segmentation Vectors Abstracts Filtering algorithms Erbium Training

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Appointments for 2005-2006 term

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IEEE Transactions on Very Large Scale Integration (VLSI) Systems 2005年第7期13卷 773-782页

作者： Ranganathan, Nagarajan Agrawal, Vishwani D. Chakradhar, Srimat T. Chakrabarty, Krishnendu Courtois, Bernard DeMara, Ronald Hu, Xiaobo Sharon Ismail, Yehea I. Jha, Niraj K. John, Lizy Kurian Ker, Ming-Dou Koren, Israel Liu, Bin-Da Marculescu, Diana Marculescu, Radu Narayanan, Vijaykrishnan Nassif, Sani R. Nowick, Steven M. Sapatnekar, Sachin S. Sherlekar, Sunil Sylvester, Dennis Vemuri, Ranga Pham, Michael Department of Computer Science and Engineering University of South Florida Tampa FL 33620 United States Department of Computer Science and Engineering Nanomaterials and Nanomanufacturing Research Center University of South Florida Tampa United States IEEE United States Systems United States Department of Electrical and Computer Engineering Rutgers University New Brunswick NJ United States IETE India ACM NEC Laboratories America Inc. Princeton NJ United States Duke University Durham NC United States ACM SIGDA Sigma Xi United States Laboratory of Techniques of Informatics and Microelectronics for Computer Architectecture ASME IMAPS IEEE Computer Society University of Central Florida Orlando United States Computer Engineering Program SEECS Department of Computer Science and Engineering University of Notre Dame Notre Dame IN United States Northwestern University Evanston IL United States Department of Electrical Engineering Princeton University Princeton NJ United States Association for Computing Machinery Austin United States UT Austin Engineering Foundation United States Department of Electronics Engineering National Chiao-Tung University Taiwan Department of Electrical and Computer Engineering University of Massachusetts Amherst United States Department of Electrical Engineering Department of Electrical and Computer Engineering Carnegie Mellon University Pittsburgh PA United States Electrical and Computer Engineering Faculty Carnegie Mellon University Pittsburgh PA United States Computer Science and Engineering Department Pennsylvania State University University Park United States IBM Austin Research Laboratory Austin TX United States Columbia University New York NY United States Department of Electrical and Computer Engineering University of Minnesota Minneapolis United States Tata Consultancy Services Centre of Excellence for Embedded Systems India Department of Electrical Engineering IIT Bombay India Department of Electrical Engineering Uni

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