When the process uncertainty size increases, even linear minimum phase systems must sacrifice desirable aggressive feedback control benefits to avoid an excessive ‘cost of feedback’, while preserving the robust stab...
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When the process uncertainty size increases, even linear minimum phase systems must sacrifice desirable aggressive feedback control benefits to avoid an excessive ‘cost of feedback’, while preserving the robust stability. With a suitable uncertainty division and a QFT controller-prefilter to command each uncertainty subset inside a controller-scheduler structure, it is possible to enhance the feedback tracking performance without an excessive bandwidth. To preserve the robust stability from any failure in the switching, each controller is designed to be stable in the whole uncertainty domain, and as accurate in command tracking as desired in its uncertainty subset.
A novel design technique for closed-loop amplifier circuits, suited to very low supply voltages, is proposed. It is based on the use of quasi-floating gate MOS transistors, thus avoiding issues encountered in true flo...
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A novel design technique for closed-loop amplifier circuits, suited to very low supply voltages, is proposed. It is based on the use of quasi-floating gate MOS transistors, thus avoiding issues encountered in true floating-gate MOS structures such as initial floating gate charge and Gain-Bandwidth product degradation. A programmable-gain inverting amplifier, a Digital to Analog Converter, and a Sample and Hold circuit, all based on this technique, are presented along with simulation results, thus illustrating the proposed approach.
A recently proposed analog cell suited to low-voltage and low power operation and named "flipped voltage follower" is applied to the design of current conveyors. Two alternative topologies are presented, bot...
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A recently proposed analog cell suited to low-voltage and low power operation and named "flipped voltage follower" is applied to the design of current conveyors. Two alternative topologies are presented, both operating at 1.5V and featuring simplicity, compactness, low power consumption and bandwidths up to 100 MHz for a 0.5μm CMOS technology. As an application example, a universal biquadratic filter is designed and simulated.
A novel design technique for closed-loop amplifier circuits, suited to very low supply voltages, is proposed. It is based on the use of quasi-floating gate MOS transistors, thus avoiding issues encountered in true flo...
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A novel design technique for closed-loop amplifier circuits, suited to very low supply voltages, is proposed. It is based on the use of quasi-floating gate MOS transistors, thus avoiding issues encountered in true floating-gate MOS structures such as initial floating gate charge and gain-bandwidth product degradation. A programmable-gain inverting amplifier, a digital to analog converter, and a sample and hold circuit, all based on this technique, are presented along with simulation results, thus illustrating the proposed approach.
A recently proposed analog cell suited to low-voltage and low power operation and named "flipped voltage follower" is applied to the design of current conveyors. Two alternative topologies are presented, bot...
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A recently proposed analog cell suited to low-voltage and low power operation and named "flipped voltage follower" is applied to the design of current conveyors. Two alternative topologies are presented, both operating at 1.5 V and featuring simplicity, compactness, low power consumption and bandwidths up to 100 MHz for a 0.5 /spl mu/m CMOS technology. As an application example, a universal biquadratic filter is designed and simulated.
Tracking feedback control trade-offs increase dangerously with arbitrarily large uncertainties in the process model. This is shown by the bounds in the QFT domain. In this context, the paper develops a theory on the c...
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Tracking feedback control trade-offs increase dangerously with arbitrarily large uncertainties in the process model. This is shown by the bounds in the QFT domain. In this context, the paper develops a theory on the contribution of the plant uncertainty to the tracking QFT bounds through a serious study of tracking bound formulas. From this, a methodology for uncertainty fragmentation is developed. It hopes to loosen the bound toughness, or the control design trade-offs. Better feedback benefits can be achieved while reducing the high-frequency amplification of noises and disturbances at the plant input at the same time. Different QFT controllers in a controller-scheduler structure should drive different uncertainty boundaries.
Service portals are systems which expose a bundle of Web services to the user, allowing the specification and subsequent execution of complex tasks defined over these individual services. Examples of situations where ...
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Service portals are systems which expose a bundle of Web services to the user, allowing the specification and subsequent execution of complex tasks defined over these individual services. Examples of situations where service portals would be valuable include making travel plans or purchasing a home. Service portals must be capable of converting an abstract user goal into a correct and optimal concrete execution plan, executing according to the plan, verifying the result against a user's stated satisfaction criteria, and in the case of satisfaction failure, initiating the appropriate recovery procedures. The basic framework needed to support this functionality, from gathering the input to generating an optimal plan and executing that plan, is a prerequisite for all service portals, yet there are currently no such commercial systems in existence, and the research literature has given only cursory treatment to some of these issues. In this paper, we describe FUSION, a comprehensive software system which provides the underlying framework for a service portal. We show how using the elements of this framework, service portal designers and architects can easily create domain-specific service portals, e.g., a travel service portal. We also present the Web services execution specification language (WSESL), a language that we have developed to describe execution plans in the context of the FUSION services model. Finally, we develop a set of data structures and algorithms for generating correct and optimal execution plans.
We discuss beneficial uses of imaging technologies in higher education that advance social justice. Misuse and ineffectiveness of shared decision making, specifically as related to power relationships and the redistri...
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