This paper presents a detailed analysis of the power-supply voltage (IR) drop scaling in DSM technologies. For the first time, the effects of temperature, electromigration and interconnect technology scaling (includin...
详细信息
This paper presents a detailed analysis of the power-supply voltage (IR) drop scaling in DSM technologies. For the first time, the effects of temperature, electromigration and interconnect technology scaling (including resistivity increase of Cu interconnects due to electron surface scattering and finite barrier thickness) are taken into consideration during this analysis. It is shown that the IR-drop effect in the power/ground (P/G) network increases rapidly with technology scaling, and using well-known counter measures such as wire-sizing and decoupling capacitor insertion with resource allocation schemes that are typically used in the present designs may not be sufficient to limit the voltage fluctuations over the power grid for future technologies. It is also shown that such voltage drops on power lines of switching devices in a clock network can introduce significant amount of skew which in turn degrades the signal integrity.
As evidenced by industrial surveys, stator related failures account for a large percentage of faults in induction machines. The objective of this paper is to provide a survey of existing techniques for detection of st...
详细信息
As evidenced by industrial surveys, stator related failures account for a large percentage of faults in induction machines. The objective of this paper is to provide a survey of existing techniques for detection of stator related faults, which include stator winding turn faults, stator core faults, temperature monitoring and thermal protection, and stator winding insulation testing. The root causes of fault inception, available techniques for detection and recommendations for further research are presented. Although the primary focus is on-line, sensorless methods that use machine voltages and currents to extract fault signatures, off-line techniques such as partial discharge detection are also examined.
The new educational system in Greece, as far as teaching of history is concerned, is characterized by a shift away from sterile memorization and towards a critical approach of historical facts and phenomena that would...
详细信息
The new educational system in Greece, as far as teaching of history is concerned, is characterized by a shift away from sterile memorization and towards a critical approach of historical facts and phenomena that would contribute in both the development of pupils' historical concept and conscience and the promotion of critical thought. This reflects the globally accepted goals of teaching history courses. Such teaching goals can be greatly supported by computer-based applications, which can offer access to vast amounts of historical texts and data to be used next to the main scholar textbook and be analyzed by pupils. Still, existing applications seem to be quite inadequate for this purpose, as they require that the pupil be already informed on a matter, before the initiation of a quest for data. We describe an intelligent information system that is designed to facilitate browsing of educational material and historical sources, thus allowing pupils to efficiently retrieve information on topics that are not yet known to them and expand in this way their historical knowledge. This can help in fulfilling the teaching goals of the new educational system.
The chalcogenide material used for phase-change applications in rewritable optical storage (Ge/sub 2/Sb/sub 2/Te/sub 5/) has been integrated with a 0.5-/spl mu/m radiation-hardened CMOS process to produce 64-Kbit memo...
详细信息
The chalcogenide material used for phase-change applications in rewritable optical storage (Ge/sub 2/Sb/sub 2/Te/sub 5/) has been integrated with a 0.5-/spl mu/m radiation-hardened CMOS process to produce 64-Kbit memory arrays. On selected arrays, electrical testing demonstrated up to 100% memory cell yield, 100-ns programming and read speeds, and write currents as low as 1 mA/bit. Devices functioned normally from -55/spl deg/C to 125/spl deg/C. Write/read endurance has been demonstrated to 1/spl times/10/sup 8/ before first bit failure. Total ionizing dose (TID) testing to 2 Mrad(Si) showed no degradation of chalcogenide memory element, but it identified a write current generator circuit degradation specific to the test chip, which can be easily corrected in the next generation of array and product. Static single-event effects (SEE) testing showed no effect to an effective linear energy transfer (LET/sub EFF/) of 98 MeV/mg/cm/sup 2/. Dynamic SEE testing showed no latchup or single-event gate rupture (SEGR) to an LET/sub EFF/ of 123 MeV/mg/cm/sup 2/. Two sensitive circuits, neither containing chalcogenide elements, and both with small error cross sections, were identified. The sense amp appears sensitive to transients when reading the high-resistance state. The write driver circuit may be falsely activated during a read cycle, resulting in a reprogrammed bit. Radiation results show no degradation to the hardened CMOS or effects that can be attributed to the phase-change material.
A panel discussion with the title Whitherto Robust Control was held during the IEEE Conference on Decision and Control in Honolulu, HI, in December 1990. Organizers and Chairs were B.R. Barmish and P.P. Khargonekar, w...
A panel discussion with the title Whitherto Robust Control was held during the IEEE Conference on Decision and Control in Honolulu, HI, in December 1990. Organizers and Chairs were B.R. Barmish and P.P. Khargonekar, while the panelists were D.S. Bernstein, S.P. Bhattacharyya, S.P. Boyd, J.C. Doyle, I.M. Horowitz and R.E. Skelton. Today, the goals of researchers working on robust control are probably quite different than thirteen years ago. This seems true both in the progress of novel theoretic paradigms as well as in the developments of new tools required by emerging applications. This panel discussion addresses classical issues and outlines future directions within robust control. We hope that it will contribute to its growth in the years to come. The panelists’ viewpoint are presented in the next pages.
Results are presented for direct chemical sensing in liquid environments using guided shear horizontal surface acoustic wave (SH-SAW) sensor platforms on 36/spl deg/ rotated Y-cut LiTaO/sub 3/. Two different sensor ge...
详细信息
Results are presented for direct chemical sensing in liquid environments using guided shear horizontal surface acoustic wave (SH-SAW) sensor platforms on 36/spl deg/ rotated Y-cut LiTaO/sub 3/. Two different sensor geometries are theoretically analyzed. Complex bulk and shear moduli are utilized to represent the viscoelastic properties of the polymers and estimate their influence on the velocity shift and attenuation change, hence on the sensor characteristics. Experimental results are presented and discussed for dual delay line devices with a reference line coated with PMMA and a sensing line coated with a chemically sensitive polymer, which acts as both a guiding layer and a sensing layer. Various chemically sensitive polymers are investigated, and the tested analytes include toluene, ethylbenzene and xylene. Analytes in the low concentration (1 ppm to 60 ppm) range in aqueous solutions are tested. Stability, sensitivity and partial selectivity are investigated by varying the coating thickness and curing temperature for the chemically sensitive layer. Partition coefficients for polymer-aqueous analyte pairs are used to explain the observed trend in sensitivity. Both mass loading and the coating viscoelasticity change influence the sensor response. A low ppb level detection limit is estimated from the present experiment measurement.
Device models for the HEMT-based THz source are developed: an all-analytical model and a model in which the electron systems in the channel is considered analytically in the linear approximation, whereas the transport...
详细信息
Device models for the HEMT-based THz source are developed: an all-analytical model and a model in which the electron systems in the channel is considered analytically in the linear approximation, whereas the transport of the photogenerated electrons and holes is treated invoking an ensemble Monte Carlo particle simulation. Using these models, the frequency-dependent currents and device responsivity as functions of the structural parameters, gate voltage, and energy of the absorbed optical photons are calculated. An example of the dependences calculated for HEMTs with the fundamental plasma frequency f/sub P/ = 1 THz and different values of the electron mobility /spl mu/ in the channel is performed.
Some of the basic innovative trends of the industrial environment, today, are the shift from centralized control architectures to distributed systems, as well as the increasing degree of heterogeneity. These features ...
详细信息
Some of the basic innovative trends of the industrial environment, today, are the shift from centralized control architectures to distributed systems, as well as the increasing degree of heterogeneity. These features impose the need for special software tools that support the design of control applications in a homogeneous and interoperable way, as well as their distribution to the interconnected participating industrial devices. The utilisation of the internet and the provision of e-services to the industry will also lead to the distribution of management functionalities in addition to control code distribution. Such an evolution requires both a new model for industrial devices as well as a design and deployment tool that will make possible the distribution of functionalities to industrial devices. This paper presents the state-of-the-art considering distributed industrial system design and concludes with a specification of distributed systems, enabling the incorporation of novel advanced functionalities.
暂无评论