1,169 research outputs found

    Pittsburgh's Failed Industry Targeting Strategy of the 1960s

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    In the 1960's and early 1970's, public and private leaders made a substantial effort to promote Pittsburgh's existing transportation industry as a center for the emerging urban transportation market. The selection of the rapid transit industry for targeting in the 1960's purportedly addressed two issues. Despite national acclaim for its Renaissance redevelopment since World War II, the metropolitan region still needed an effective mass transportation system. Moreover, industrial development efforts had not substantially diversified the region's manufacturing base that still specialized in primary metals. Operating in the region's Renaissance tradition of a public and private partnership, corporate executives and public officials pursued a three-pronged strategy: build an innovative rapid transportation system for Allegheny County, use it as a showcase for testing and marketing rapid transit hardware of regional corporations, and promote the city as a center of the rapid transportation industry. They settled on Westinghouse's automated, rubber-tired vehicle running on a separate cement guideway, known locally as "Skybus," for the demonstration project and the region's mass transit solution. The mass transit plan and industry targeting strategy foundered by the early 1970's because leadership weakened in both poles of the partnership. The Westinghouse technology divided the corporate community, while populist political sentiment diminished the ability of the Democratic party's political machine to deliver key public decisions. The Pittsburgh case suggests that a successful industry targeting strategy may depend more on effective leadership and local politics than on the quality of the selection process and vigorous pursuit of traditional economic development programs in support of the targeted industry

    Controlling flexible structures: A survey of methods

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    Most of the presently available control system design techniques applicable to flexible structure problems were developed to design controllers for rigid body systems. Although many of these design methods can be applied to flexible dynamics problems, recently developed techniques may be more suitable for flexible structure controller design. The purpose of this presentation is to examine briefly the peculiarities of the dynamics of flexible structures and to stimulate discussion about top level controller design approaches when designing controllers for flexible structures. Presented here is a suggestion of a set of categories of design methods for designing controllers for flexible structures as well as a discussion of the advantages and disadvantages of each category. No attempt has been made herein to select one category of design techniques as the best for flexible structure controller design. Instead, it is hoped that the structure suggested by these categories will facilitate further discussion on the merits of particular methods that will eventually point to those design techniques suitable for further development

    Surface interactions between nickel ions and sodium dodecyl sulfate

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    In this research the interaction of nickel ions with the surfactant sodium dodecyl sulfate at the liquid-air interface was studied. Surface tension measurements were performed on pure sodium dodecyl sulfate solutions, with and without the addition of nickel ions. Results of these measurements showed that the addition of nickel ions lowered the equilibrium surface tension values of pure sodium dodecyl sulfate solutions and shifted the critical micelle concentration to lower concentrations. The foam fractionation technique was used to determine if the nickel ions could be removed from surfactant solutions. It was found that the removal of nickel ions was influenced by pH and SDS concentrations --Abstract, page ii

    Modeling and control system design and analysis tools for flexible structures

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    Described here are Boeing software tools used for the development of control laws of flexible structures. The Boeing Company has developed a software tool called Modern Control Software Package (MPAC). MPAC provides the environment necessary for linear model development, analysis, and controller design for large models of flexible structures. There are two features of MPAC which are particularly appropriate for use with large models: (1) numerical accuracy and (2) label-driven nature. With the first feature MPAC uses double precision arithmetic for all numerical operations and relies on EISPAC and LINPACK for the numerical foundation. With the second feature, all MPAC model inputs, outputs, and states are referenced by user-defined labels. This feature allows model modification while maintaining the same state, input, and output names. In addition, there is no need for the user to keep track of a model variable's matrix row and colunm locations. There is a wide range of model manipulation, analysis, and design features within the numerically robust and flexible environment provided by MPAC. Models can be built or modified using either state space or transfer function representations. Existing models can be combined via parallel, series, and feedback connections; and loops of a closed-loop model may be broken for analysis

    Design of integrated pitch axis for autopilot/autothrottle and integrated lateral axis for autopilot/yaw damper for NASA TSRV airplane using integral LQG methodology

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    Two designs are presented for control systems for the NASA Transport System Research Vehicle (TSRV) using integral Linear Quadratic Gaussian (LQG) methodology. The first is an integrated longitudinal autopilot/autothrottle design and the second design is an integrated lateral autopilot/yaw damper/sideslip controller design. It is shown that a systematic top-down approach to a complex design problem combined with proper application of modern control synthesis techniques yields a satisfactory solution in a reasonable period of time

    An Evaluation of Performance and Structural Change in Employment- U.S., Nebraska, and Omaha Area Economies, 1988 to 1995

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    A periodic comparative evaluation of employment and its composition is worthwhile since employment is one of the most basic determinants of the health of the economy and quality of life. Changes in employment over time reflect restructuring of an economy and, ultimately, have social impacts. Moreover, the underlying trends of employment give an indication of an economy\u27s future growth and wellbeing. A future article will evaluate personal income as a measure of economic performance. This article examines employment data developed by the U. S. Department of Commerce, Bureau of Economic Analysis (BEA) and compiled by the Bureau of Business Research (BBR). To provide a consistent and comparable analysis, the initial and terminal years of the study, 1988 and 1995, both represent periods of healthy economic growth. The data tables summarize the economies of the U. S. (Table I), Nebraska (Table 2) and the Omaha Area (Tables 3 and 4). The Omaha area includes the Nebraska counties of Douglas, Sarpy, and Washington in Table 3. Pottawattamie County, Iowa is added to the Omaha area in Table 4. Pottawattamie County is also presented separately in Table 5 to show its growth relative to the rest of the Omaha Area. Employment Changes Summary of Employment Changes in the Economies Conclusio

    Pay-for-Performance Systems in State Government: Perceptions of State Agency Personnel Managers*

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    Pay for performance has been a widely used method of compensation in the public sector since the early 1980s, but a growing body of research has indicated that numerous problems can be associated with the application of performance-based compensation systems In late 1993, the federal government, after years of difficulty experienced with its merit pay program, took a significant step back from pay for performance through passage of the Performance Management and Recognition System Termination Act This research seeks to determine whether state governments are becoming similarly disenchanted with pay for performance To gain insight into this question, a survey was administered to a nationwide random sample of state agency personnel management executives Results indicate that pay for performance remains as popular as ever in state government, and that nearly all of the systems in the states utilize merit pay despite difficulties often associated with that approach to pay for performance.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Variations in the Compositon of Steffens Waste II

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    Steffens waste is the filtrate from the precipitation of sugar from beet molasses by the addition of lime. The molasses, as it comes from the beet sugar extraction process, contains about 50 per cent sugar, so it is too valuable to be fermented to produce alcohol in this country, although in Europe, much of the beet molasses goes directly to production of alcohol by fermentation
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