8,531 research outputs found

    Multiple man-machine interfaces

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    The multiple man machine interfaces inherent in military pilot training, their social implications, and the issue of possible negative feedback were explored. Modern technology has produced machines which can see, hear, and touch with greater accuracy and precision than human beings. Consequently, the military pilot is more a systems manager, often doing battle against a target he never sees. It is concluded that unquantifiable human activity requires motivation that is not intrinsic in a machine

    Matanuska Valley Memoir

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    We acknowledge indebtedness to the historians and developers of Alaskana who preceded us and provided much of the information we have compiled into our account of the birth of a community. Many "old timers" from the Valley provided valuable insight into situations they had experienced. Mr. Roland Snodgrass, Mrs, June Murphy and Miss Dolores Pommier assisted in compilation and preparation of background data. Mr. James Hurley made available to us the ARRC unpublished files for compilation of certain data. Various public officials aided us in many ways as we worked· our way through recorded . history. Several old photos were contributed by Mr. Walter Teeland of Wasilla and Mr. Don L. Irwin of Palmer. Several persons in public and private life who know Alaskan conditions have reviewed the manuscript and suggested improvements, Special acknowledgement is due Don L. Irwin, Director of the Alaska Agricultural Experiment Station, His vision and foresight were largely responsible for the undertaking, His encouragement and advice bolstered our lagging spirits before the long task was completed. He has read each chapter critically and has assisted particularly with interpretation of materials since 1935,The Matanuska Valley was created through action of ice, water and wind. When the last glaciers retreated up the Susitna, the Knik and the Matanuska valleys, vegetation began cove ring the scars, Over several centuries a dense growth of trees and brush screened the land from Knik Arm to the mountain slopes of the Talkeetna range . Here and there a lake broke the uniform forest mantle. A salt marsh at the mouth of the Matanuska River kept the rank undergrowth from reaching tide water, A few low spots near the Little Susitna and other swampy areas supported a thick cover of moss or grass. The Valley, which really isn't a valley at all but a reworked foreland, rises from the Matanuska River in a series of benches ranging in width from a few hundred feet to more than a mile. Some areas are flat, others are rolling. Soil depth varies from eight feet in thickness for the region bordering the Matanuska River to a few inches in sections west of Wasilla. The soil mantle, of windblown loessial materials, is of relatively new geologic development, The Valley is bounded by the Chugach Mountains on the east, the Talkeetnas on the north, the Susitna Valley on the west and Knik Arm on the south. Winters are long but usually not unduly severe; summers cool and relatively moist, To this country came trappers, prospectors and traders in closing years of the nineteenth century. Hordes of insects, difficult trails, sparse population and great distance s from supply points discouraged many potential residents, Those who stayed were interested primarily in the Willow Creek gold field or the Matanuska coal deposits. Another generation, an uneasy international situation and social crises within the United States were required before the Matanuska Valley and the rest of Upper Cook Inlet were ripe for use. This history of the Valley is designed to trace the many human elements affecting the ebb and flow of agricultural development here. It brings into focus many problems that must be solved before new areas in Alaska can be settled satisfactorily

    NASTRAN as a resource in code development

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    A case history is presented in which the NASTRAN system provided both guidelines and working software for use in the development of a discrete element program, PATCHES-111. To avoid duplication and to take advantage of the wide spread user familiarity with NASTRAN, the PATCHES-111 system uses NASTRAN bulk data syntax, NASTRAN matrix utilities, and the NASTRAN linkage editor. Problems in developing the program are discussed along with details on the architecture of the PATCHES-111 parametric cubic modeling system. The system includes model construction procedures, checkpoint/restart strategies, and other features

    A public relations guide for military commanders

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    Thesis (M.S.)--Boston Universit

    Involute composite design evaluation using global design sensitivity derivatives

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    An optimization capability for involute structures has been developed. Its key feature is the use of global material geometry variables which are so chosen that all combinations of design variables within a set of lower and upper bounds correspond to manufacturable designs. A further advantage of global variables is that their number does not increase with increasing mesh density. The accuracy of the sensitivity derivatives has been verified both through finite difference tests and through the successful use of the derivatives by an optimizer. The state of the art in composite design today is still marked by point design algorithms linked together using ad hoc methods not directly related to a manufacturing procedure. The global design sensitivity approach presented here for involutes can be applied to filament wound shells and other composite constructions using material form features peculiar to each construction. The present involute optimization technology is being applied to the Space Shuttle SRM nozzle boot ring redesigns by PDA Engineering

    Experimental and modal verification of an integral equation solution for a thin-walled dichroic plate with cross-shaped holes

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    In order to add the capability of an X-band uplink onto the 70-m antenna, a new dichroic plate is needed to replace the Pyle-guide-shaped dichroic plate currently in use. The replacement dichroic plate must exhibit an additional passband at the new uplink frequency of 7.165 GHz, while still maintaining a passband at the existing downlink frequency of 8.425 GHz. Because of the wide frequency separation of these two passbands, conventional methods of designing air-filled dichroic plates exhibit grating lobe problems. A new method of solving this problem by using a dichroic plate with cross-shaped holes is presented and verified experimentally. Two checks of the integral equation solution are described. One is the comparison to a modal analysis for the limiting cross shape of a square hole. As a final check, a prototype dichroic plate with cross-shaped holes was built and measured

    Reliability of perceptions of voice quality: evidence from a problem asthma clinic population

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    <p>Introduction: Methods of perceptual voice evaluation have yet to achieve satisfactory consistency; complete acceptance of a recognised clinical protocol is still some way off.</p> <p>Materials and methods: Three speech and language therapists rated the voices of 43 patients attending the problem asthma clinic of a teaching hospital, according to the grade-roughness-breathiness-asthenicity-strain (GRBAS) scale and other perceptual categories.</p> <p>Results and analysis: Use of the GRBAS scale achieved only a 64.7 per cent inter-rater reliability and a 69.6 per cent intra-rater reliability for the grade component. One rater achieved a higher degree of consistency. Improved concordance on the GRBAS scale was observed for subjects with laryngeal abnormalities. Raters failed to reach any useful level of agreement in the other categories employed, except for perceived gender.</p> <p>Discussion: These results should sound a note of caution regarding routine adoption of the GRBAS scale for characterising voice quality for clinical purposes. The importance of training and the use of perceptual anchors for reliable perceptual rating need to be further investigated.</p&gt

    Microstructured Optical Fiber for X-ray Detection

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    A novel scintillating optical fiber is presented using a composite micro-structured quartz optical fiber. Scintillating materials are introduced into the multiple inclusions of the fiber. This creates a composite optical fiber having quartz as a cladding with an organic scintillating material core. X-ray detection using these fibers is compared to a collimated cadmium telluride (CdTe) detector over an energy range from 10 to 40 keV. Results show a good correlation between the fiber count rate trend and that of the CdTe detector
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