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11.
The structure, chemical composition, and magnetic properties of electrochemically deposited nanocrystalline Co-Ni-Fe films
were investigated using a number of techniques. A high saturation magnetic induction up to B
s
= 21 kG was attained. An enhancement of the saturation magnetization compared to the ideal anticipated one was revealed,
which correlated with the nonlinear behavior of the structural phase composition and lattice parameters with the change of
the composition.
The text was submitted by the authors in English. 相似文献
12.
Rogin J. Kouchev I. Brenna G. Tschopp D. Qiuting Huang 《Solid-State Circuits, IEEE Journal of》2003,38(12):2239-2248
A 2-GHz direct-conversion receiver for wide-band code division multiple access (WCDMA) is presented. It includes two low-noise amplifiers (LNAs), an I/Q demodulator, and two sixth-order baseband channel select filters with programmable gain. Quadrature local oscillator (LO) signals are generated on chip in a frequency divider flip-flop. An external interstage filter between the LNAs rejects transmitter leakage to relax demodulator linearity requirements. A low-voltage demodulator topology improves linearity as well as demodulator output pole accuracy. The active-RC baseband filter uses a programmable servo loop for offset compensation and provides an adjacent channel rejection of 39 dB. Programmable gain over 71-dB range in 1-dB steps is merged with the filter to maximize dynamic range. An automatic on-chip frequency calibration scheme provides better than 1.5% corner frequency accuracy. The receiver is integrated in a 0.13-/spl mu/m CMOS process with metal-insulator-metal (MIM) capacitors. Measured receiver performance includes a 6.5-dB noise figure, IIP2 of +27 dBm, and IIP3 of -8.6 dBm. Power consumption is 45 mW. 相似文献
13.
Hook T.B. Brown J. Cottrell P. Adler E. Hoyniak D. Johnson J. Mann R. 《Electron Devices, IEEE Transactions on》2003,50(9):1946-1951
Lateral scattering of retrograde well implants is shown to have an effect on the threshold voltage of nearby devices. The threshold voltage of both NMOSFETs and PMOSFETs increases in magnitude for conventional retrograde wells, but for triple-well isolated NMOSFETs the threshold voltage decreases for narrow devices near the edge of the well. Electrical data, SIMS, and SUPREM4 simulations are shown that elucidate the phenomenon. 相似文献
14.
Piedade M. Sousa L. A. de Almeida T. M. Germano J. da Costa B. A. Lemos J. M. Freitas P. P. Ferreira H. A. Cardoso F. A. 《IEEE transactions on circuits and systems. I, Regular papers》2006,53(11):2384-2395
This paper presents a hand-held microsystem based on new fully integrated magnetoresistive biochips for biomolecular recognition (DNA hybridization, antibody antigen interaction, etc.). Magnetoresistive chip surfaces are chemically treated, enabling the immobilization of probe biomolecules such as DNA or antibodies. Fluid handling is also integrated in the biochip. The proposed microsystem not only integrates the biochip, which is an array of 16times16 magnetoresistive sensors, but it also provides all the electronic circuitry for addressing and reading out each transducer. The proposed architecture and circuits were specifically designed for achieving a compact, programmable and portable microsystem. The microsystem also integrates a hand-held analyzer connected through a wireless channel. A prototype of the system was already developed and detection of magnetic nanoparticles was obtained. This indicates that the system may be used for magnetic label based bioassays 相似文献
15.
WiFi access point pricing as a dynamic game 总被引:1,自引:0,他引:1
We study the economic interests of a wireless access point owner and his paying client, and model their interaction as a dynamic game. The key feature of this game is that the players have asymmetric information - the client knows more than the access provider. We find that if a client has a "web browser" utility function (a temporal utility function that grows linearly), it is a Nash equilibrium for the provider to charge the client a constant price per unit time. On the other hand, if the client has a "file transferor" utility function (a utility function that is a step function), the client would be unwilling to pay until the final time slot of the file transfer. We also study an expanded game where an access point sells to a reseller,which in turn sells to a mobile client and show that if the client has a web browser utility function, that constant price is a Nash equilibrium of the three player game. Finally, we study a two player game in which the access point does not know whether he faces a web browser or file transferor type client, and show conditions for which it is not a Nash equilibrium for the access point to maintain a constant price. 相似文献
16.
We report for the first time optical signal-to-noise penalties which lead to performance degradations in single-fiber long-reach optical access networks when compared to identical dual-fiber systems. A simplified architecture, with reduced optical amplifier count compared to previous work, for single-fiber operation of a symmetrical 10-Gb/s, 1024-way split, 110-km long-reach optical access network is presented and demonstrated. In addition, a possible solution to remove the optical signal-to-noise penalty is suggested 相似文献
17.
A multi-level attention framework for tracking and segmentation of humans and objects under complex occlusions is investigated,
featuring an effective probabilistic appearance-based technique for pixel reclassification during object grouping and splitting.
A novel ’spatial-depth affinity metric’ is introduced in the conventional likelihood function, utilising information of both
spatial locations of pixels and dynamic depth ordering of the component objects in grouping. Depth ordering estimation is
achieved through a combination of top-down and bottom-up approach. Experiments on some realworld difficult scenarios of low
quality and highly compressed videos demonstrate the very promising results achieved. 相似文献
18.
Gundolf Kiefer Helko Lehmann Jürgen Weese 《IEEE transactions on information technology in biomedicine》2006,10(2):385-394
Maximum intensity projections (MIPs) are an important visualization technique for angiographic data sets. Efficient data inspection requires frame rates of at least five frames per second at preserved image quality. Despite the advances in computer technology, this task remains a challenge. On the one hand, the sizes of computed tomography and magnetic resonance images are increasing rapidly. On the other hand, rendering algorithms do not automatically benefit from the advances in processor technology, especially for large data sets. This is due to the faster evolving processing power and the slower evolving memory access speed, which is bridged by hierarchical cache memory architectures. In this paper, we investigate memory access optimization methods and use them for generating MIPs on general-purpose central processing units (CPUs) and graphics processing units (GPUs), respectively. These methods can work on any level of the memory hierarchy, and we show that properly combined methods can optimize memory access on multiple levels of the hierarchy at the same time. We present performance measurements to compare different algorithm variants and illustrate the influence of the respective techniques. On current hardware, the efficient handling of the memory hierarchy for CPUs improves the rendering performance by a factor of 3 to 4. On GPUs, we observed that the effect is even larger, especially for large data sets. The methods can easily be adjusted to different hardware specifics, although their impact can vary considerably. They can also be used for other rendering techniques than MIPs, and their use for more general image processing task could be investigated in the future. 相似文献
19.
Dell'Amico M. Maffioli F. Merani M.L. 《Wireless Communications, IEEE Transactions on》2004,3(4):1013-1017
This paper proposes some novel techniques to accommodate users with different rate requirements in a wideband code-division multiple-access system employing orthogonal variable spreading factor codes. Two simple static code assignment strategies are first considered, and an improvement based on multicode assignment. Then the new idea of tree partitioning is introduced and used to devise a dynamic code reassignment algorithm. The behavior of these different techniques is experimentally investigated, in terms of call blocking probability and number of required reassignments. The tree partitioning method exhibits very good performances. 相似文献
20.
Two types of photo heterojunction bipolar transistor (HBT) to directly down-convert optical signals to electronic signals have been reported in the literature: a conventional photo-HBT in which light penetrates through the area of the base-collector junction and an HBT where light shines through the base-collector edge for higher conversion efficiency. Although the performance in relation to bias conditions has been published, the detailed analyses for identifying the parameters and bias conditions that provide optimum direct down-conversion have not been examined. This paper provides a full explanation of the operation of the down-conversion for both HBT configurations based on low-frequency analyses. Such information is useful for both understanding the nonlinear mechanisms involved and designing for maximum efficiency. In addition, a new circuit has been developed from the basic HBT down-conversion circuit that provides improved performance. 相似文献