A coaxial quadrature bridge based on digital synthesis has been developed. The bridge compares two resistance standards (having nominal resistance R) with two capacitance standards (nominal capacitance C) at an angula...
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A coaxial quadrature bridge based on digital synthesis has been developed. The bridge compares two resistance standards (having nominal resistance R) with two capacitance standards (nominal capacitance C) at an angular frequency omega (such that omega RC approximate to 1). All standards are defined as two terminal-pair impedances. All voltages and currents employed in the bridge are generated by a multiphase direct digital synthesizer constructed around a personal computer digital-to-analog converter (DAC) board and a set of buffer amplifiers;the number of electromagnetic devices has been kept to a minimum. The purpose of the bridge is to be employed in the realization of the farad unit, starting from the representation of ohm given by the quantum Hall effect. The relative bridge accuracy during the calibration of 1000-pF capacitors in terms of 100-k Omega resistors at omega = 10 krad . s(-1) has been verified to be less than 10(-6);preliminary uncertainty assignments give a transfer uncertainty of a few parts in 10(8).
Domain modeling can be applied to collections of reusable designs and reusable software. Libraries of such collections can be used when applying a refinement by transformation technique to software construction. There...
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Domain modeling can be applied to collections of reusable designs and reusable software. Libraries of such collections can be used when applying a refinement by transformation technique to software construction. There already exist systems that can automatically or semi-automatically perform program transformations that constitute refinements. An important question is how to organize such libraries so that transformation tools may feasibly use them. We show that transformation of a high level program with constraints on the transformations is an NP-complete problem;however, appropriately organized libraries are tractable. Moreover, we define a property which a library of transformations can have, ensuring that any consistent high level program can be transformed into an executable form. Finally, we give approximations which reduce the complexity of transformations for libraries which do not have this property. The most important aspect of this work is that it implies certain rules should be followed in constructing libraries and the domains that are placed in them.
An analogy is established between the minimization problems of software design based on decision tables and the problem of minimizing relay tree switching networks. The analogy facilitates the adoption of a large numb...
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An analogy is established between the minimization problems of software design based on decision tables and the problem of minimizing relay tree switching networks. The analogy facilitates the adoption of a large number of techniques developed for the design of computer hardware by the designers of computer software.
Developments now pending will alter the character of SP, as we presently know it, beyond recognition. SP is essentially a discipline for a programming shop that turns out programs in response to assignments. It enable...
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Developments now pending will alter the character of SP, as we presently know it, beyond recognition. SP is essentially a discipline for a programming shop that turns out programs in response to assignments. It enables better planning and control of software development work and improves productivity of the programmers. New technology will alter the roles of the chief programmer and the members of his team.
A technique for generating driving waveforms having non-linear dependence on an independent variable is described. Forward biased high-conductance silicon diodes are used as feedback elements in an operational amplifi...
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A technique for generating driving waveforms having non-linear dependence on an independent variable is described. Forward biased high-conductance silicon diodes are used as feedback elements in an operational amplifier circuit. A FORTRAN time-sharing computer program has been written and used to aid in the selection of circuit components. A radio frequency program generator has been designed and built to provide the drive to a voltage-controlled oscillator as a function of the NAL main accelerator bend magnet current.
RMAS is a multi-agent system architecture and associated model of computation that has been recently proposed as promising framework for autonomic computation and as viable implementation means for industrial agents. ...
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RMAS is a multi-agent system architecture and associated model of computation that has been recently proposed as promising framework for autonomic computation and as viable implementation means for industrial agents. RMAS is proposed as an effective tool in the realization of the full-fledged concept of cyber-physical systems of systems, in agreement with new visions of the digital future and prominent standardization efforts like the IEC 61499. Currently, there is the need to establish a solid formalism for the model of computation of RMAS in order to harness and fully express its possibilities. In particular, this model should bridge the disciplines of control and systems engineering and computer science, whilst concerning artificial intelligence. This work proposes a first operational step in this direction. A formalism of the RMAS model of computation is established for the first time, and a complete definition of hierarchical nested levels of RMAS units is proposed. This work constitutes the ground for industry-ready technological instances of the RMAS architecture. (C) 2022 The Authors. Published by Elsevier B.V.
This paper describes an automatic multi-objective adjustment system for optical axes using genetic algorithms. It is difficult for conventional systems to automatically adjust optical axes, because it requires high-pr...
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ISBN:
(纸本)0769522866
This paper describes an automatic multi-objective adjustment system for optical axes using genetic algorithms. It is difficult for conventional systems to automatically adjust optical axes, because it requires high-precision positioning and angle setting with mu m resolution. Moreover multiple goals that have a trade-off relation must be satisfied simultaneously by the adjustment. In order to overcome this problem, we propose a multi-objective adjustment system using genetic algorithms. In experiments, simultaneous alignment for the positioning and the angles (parallelism) of optical axes, which is difficult with conventional methods, could be realized within three hours.
The process of surface design and programming method of NC machining with Pro/E is introduced. By designing and NC machining of fan blades, the method of designing and automatic programming of free form surface by usi...
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ISBN:
(纸本)9783037857649
The process of surface design and programming method of NC machining with Pro/E is introduced. By designing and NC machining of fan blades, the method of designing and automatic programming of free form surface by using of parameters materialized is described. And its cutting path is planed reasonably. At last, the NC program is derived.
Traditional design and implementation of large atmospheric models is a difficult, tedious and erroneous task. With the CTADEL project we propose a new method of code generation, where the designer describes the model ...
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ISBN:
(纸本)3540435913
Traditional design and implementation of large atmospheric models is a difficult, tedious and erroneous task. With the CTADEL project we propose a new method of code generation, where the designer describes the model in an abstract high-level specification language which is translated into highly optimized Fortran code. In this paper we show the abilities of this method on a coupled ocean-atmosphere model, in which we have to deal with multi-resolution domains and different time-steps. We, briefly, describe a new concept in compiler design, the use of templates for code generation, to elevate the burden of choosing architecture optimized numerical routines.
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