1,837 research outputs found

    Research in the effective implementation of guidance computers with large scale arrays Interim report

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    Functional logic character implementation in breadboard design of NASA modular compute

    Concepts in LSI servo-control-electronics

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    This thesis deals with the engineering aspects of control electronics. It examines modern concepts of servo-control theory in the light of recent developments in the technology of monolithic circuits. Applicational considerations are slanted towards Aerospace standards of reliability and power-consumption economy. Conclusions drawn from the discussion of fabrication constraints and performance requirements lead to a preference for digital implementations. Yield problems on one hand and aging effects on the other greatly reduce the feasibility rating of analog arrays. Current practice in servo-control electronics revolves around purely analog implementations, sampled-data systems and Primitive on-off arrangements. The motivation behind the status quo and the justification of the proposed approach are discussed in detail. The organization of digital systems is examined in order to demonstrate the feasibility of Large Scale Integration (LSI) in servo-control electronics. The questions of hardware versatility and power-dissipation economy are emphasized from technological, economical and applicational standpoints. Self-Contained loops and Computer-Aided systems investigated within the ramifications of a functional division into Detectors, Compensators and Drivers. Differential Frequency Modulation is assumed to effect the information transfer from the Pick-Off coil of the transducer to tie input ports of the Ratemeter. Pulse Width-Frequency Modulation is employed at the Driver-Torquer interface. The operation of the Ratameter conforms with classical logic, except for a slope-independent Level-Crossing-Discriminator (LCD), which is designed to provide a time-resolution gain of 3 db. over conventional frequency detectors. Circuit detais of the LCD are given in order to illustrate differences between integrated and discrete circuit configurations. Two types of compensators are discussed: canonic pole-zero arrangements with ROM multipliers and Kalman fiiters with stored-program implementations of covariance equations. The concept of Pulse-Width-Frequency-Modulation (PWFM) is introduced co reconcile the dynamic-range requirements or servo-control drivers with the time-resolution limitations of power transistors. Simple means of implementation of PWFM are also given; they take the form. of a combination of logic-gates and DDA elements, a technique which could be used to advantage in other applications, especially digital detection and filtration

    Interfaces, modularity and ecosystem emergence: How DARPA modularized the semiconductor ecosystem

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    Scholars have identified the pivotal role that modularity plays in promoting innovation. Modularity affects industry structure by breaking up the value chain along technical interfaces, thereby allowing new entrants to specialize and innovate. Less well-understood is where modularity comes from. Firms seem to behave consistently with the theory in some settings, especially the information technology sector, but not in others, such as automobiles. Here we show how the government has a role to play in generating open interfaces needed for modularity, utilizing a case study of the semiconductor industry from 1970 to 1980. We show how the Defense Department\u27s support for this effort aligned with its mission-based interest in semiconductors. We thus contribute a new source of open standards to the modularity literature, as well as a new analytical perspective to the public research funding literature

    seihin kaihatsu ni okeru sekkei fuka to sono teigen : sekkei purosesu no koritsuka to kaizen ni kansuru kenkyu

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    制度:新 ; 文部省報告番号:甲2267号 ; 学位の種類:博士(学術) ; 授与年月日:2006/9/15 ; 早大学位記番号:新429

    Product assurance technology for custom LSI/VLSI electronics

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    The technology for obtaining custom integrated circuits from CMOS-bulk silicon foundries using a universal set of layout rules is presented. The technical efforts were guided by the requirement to develop a 3 micron CMOS test chip for the Combined Release and Radiation Effects Satellite (CRRES). This chip contains both analog and digital circuits. The development employed all the elements required to obtain custom circuits from silicon foundries, including circuit design, foundry interfacing, circuit test, and circuit qualification

    Functional requirements for the man-vehicle systems research facility

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    The NASA Ames Research Center proposed a man-vehicle systems research facility to support flight simulation studies which are needed for identifying and correcting the sources of human error associated with current and future air carrier operations. The organization of research facility is reviewed and functional requirements and related priorities for the facility are recommended based on a review of potentially critical operational scenarios. Requirements are included for the experimenter's simulation control and data acquisition functions, as well as for the visual field, motion, sound, computation, crew station, and intercommunications subsystems. The related issues of functional fidelity and level of simulation are addressed, and specific criteria for quantitative assessment of various aspects of fidelity are offered. Recommendations for facility integration, checkout, and staffing are included
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