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991.
An enterprise is not just a tall shiny building or a collection of facilities. Rather, it is the sum of individuals collectively engaged in a common pursuit. From an information and communications perspective, this realization changes everything. By looking at the enterprise as a boundary-less collection of individuals who sometimes work in an office, sometimes at home, and sometimes on the road, we need new communications concepts designed to work with and enhance our complex home and work lives.  相似文献   
992.
In this practical case study the method of self-organizing map (SOM) neural net is applied to analyze a CMOS process problem, where the device under study is a heartbeat rate monitor integrated circuit. The wafer yield is analyzed against the process control monitoring (PCM) parameter measurement values. The SOM efficiently reduces the parameter space dimensions and helps in visualizing the different parameter relations. This makes it possible to identify the most probable PCM parameters affecting the yield. Those were found out to be NMOS transistor drain current and aluminium sheet resistance.  相似文献   
993.
994.
The concept and structure of the NANODEV simulation software are described. NANODEV deals with nanoelectronic devices that exploit single-electron tunneling, resonant tunneling, or quantum interference. It can use both simplified and sophisticated models and enables one to evaluate a wide variety of devices and configurations. The capabilities of NANODEV are illustrated by examples.  相似文献   
995.
A novel driver-assist stability system for all-wheel-drive electric vehicles is introduced. The system helps drivers maintain control in the event of a driving emergency, including heavy braking or obstacle avoidance. The system comprises a fuzzy logic system that independently controls wheel torque to prevent vehicle spin. Another fuzzy wheel slip controller is used to enhance vehicle stability and safety. A neural network is trained to generate the required reference for yaw rate. Vehicle true speed is estimated by a sensor data fusion method. The intrinsic robustness of fuzzy controllers allows the system to operate in different road conditions successfully. Moreover, the ease of implementing fuzzy controllers gives a potential for vehicle stability enhancement.  相似文献   
996.
A new dual-quantisation sigma-delta modulator is proposed, which introduces an additional feedback path in the input of the second integrator. In this way, unlike other dual-quantisation architectures, larger signal-to-noise ratios can be obtained by means of aggressive noise-shaping, like in a conventional multibit modulator. The proposed modulator is also shown to be more robust against non-idealities than other dual-quantisation architectures.  相似文献   
997.
Pozar  D.M. 《Electronics letters》2003,39(21):1490-1491
It is shown that the dominant factor controlling reflectarray bandwidth is the bandwidth of the radiating element, and that the effect of non-constant path delays over the surface of the flat reflector has little significance unless the aperture is electrically very large and the f/D ratio is small. An example of a polarisation-twist reflectarray using aperture coupled elements with time delay lines is used to demonstrate this conclusion.  相似文献   
998.
Optimal space-time constellations from groups   总被引:10,自引:0,他引:10  
We consider the design of space-time constellations based on group codes for fading channels with multiple transmit and receive antennas. These codes can be viewed as multiantenna extensions of phase-shift keying (PSK), in the sense that all codewords have equal energy, all are rotations of a fixed codeword, and there is a simple differential transmission rule that allows data to be sent without channel estimates at the transmitter or receiver. For coherent detection, we show that all optimal full-rank space-time group codes are unitary (each code matrix has equal-energy, orthogonal rows). This leads to a simpler code design criterion and suggests that unitary codes may play an important role in coherent as well as noncoherent communication. For any number of transmit antennas t, we then use the design criterion to characterize all full-rank unitary space-time group codes of minimum block length (also t) which have 2/sup p/ codewords. These results allow us to characterize all optimal 2/sup p/-ary unitary group codes with square code matrices. This restricted class of block codes matches the class proposed for differential modulation by Hughes (see IEEE Trans. Inform. Theory, vol.46, p.2567-78, Nov. 2000), and by Hochwald and Sweldens (see IEEE Trans. Commun., vol.48, p.2041-2052, Dec. 2000).  相似文献   
999.
1000.
Reviews the book by Baruss (see record 2003-02669-000), which reviews the experimental and phenomenological research on alterations of consciousness, ranging from sleep and dreaming to mystical and near-death experience. The reviewer suggests there is a clear agenda announced by the book's subtitle, "An Empirical Analysis for Social Scientists." In the view of Baruss, all too often in states of consciousness research a preoccupation with theory has kept investigators from full engagement with the actual data. The book provides readable and at times appropriately controversial discussions of empirical literature on dreaming and lucid dreams, daydreaming and fantasy proneness, hypnosis, dissociative identity disorder, shamanism and possession states, psychedelic drug research, parapsychology, trance-chanelling and mediumship, the alien abduction syndrome, classical mystical experience, out-of-body and near-death experiences, and recent attempts by MacDonald and others to assess individual differences in spirituality through multifactor questionnaires. However, the reviewer believes that the breadth of coverage of both recent and past research is too often highly selective, and that the author's rejection of theory is both questionable in itself and more illusion than reality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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