摘要 :
Armor Transparent Purchase Description (ATPD) 2352 revision P was issued in July 2008 to create a new standard for transparent armor aimed at improving battlefield performance, maintenance costs, equipment survivability, and gener...
展开
Armor Transparent Purchase Description (ATPD) 2352 revision P was issued in July 2008 to create a new standard for transparent armor aimed at improving battlefield performance, maintenance costs, equipment survivability, and general durability based on data collected from performance of transparent armor in the battlefield. A transparent armor specifically focused on satisfying all of the ATPD 2352 requirements was invented, developed, and commercialized. A Cooperative Research and Development Agreement with TARDEC resulted in evaluating armor to all the metrics of ATPD 2352. This paper reports on this initial and subsequent work and: (a) explains the requirements of ATPD 2352 and the challenges they present from a materials properties, armor performance, lifetime testing, transparency, durability, and environmental perspective; (b) presents data, analysis, and preliminary modeling showing the materials and performance properties of a variety of materials to highlight how and why a discontinuously nano-reinforced glass system was able to pass all the requirements; (c) describes the tests and presents test data on the key tests performed for ATPD 2352, including ballistic, environmental, and optical, many never successfully mastered in transparent armor before.
收起
摘要 :
An Interlaboratory Study (ILS) was undertaken in order to determine the precisionof the test method for measuring the angular displacement of multiple images by transparent parts. Multiple imaging is defined as the angular separat...
展开
An Interlaboratory Study (ILS) was undertaken in order to determine the precisionof the test method for measuring the angular displacement of multiple images by transparent parts. Multiple imaging is defined as the angular separation of secondary images from their respective primary images as viewed from the design eye position of an aircraft transparency. Newer aircraft now utilize thick, curved, highly angled transparencies resulting in multiple imaging being more frequently cited as an optical problem by pilots. Secondary images vary in intensity and displacement across the transparency thus giving the observer deceptive cues of attitude, velocity and approach angle. Test method F 1165-88 standardizes the measurement technique. This IS determined the precision of this method.
收起
摘要 :
Aircraft transparencies are susceptible to numerous optical characteristics which may impact the visual performance of the aircrew. These characteristics range in severity from simply distracting to hazardous. This report describe...
展开
Aircraft transparencies are susceptible to numerous optical characteristics which may impact the visual performance of the aircrew. These characteristics range in severity from simply distracting to hazardous. This report describes and illustrates the ten most common of these optical characteristics. It may be used as a guide by aircrews, maintenance personnel, and others working with transparencies to assist them in accurately identifying transparency optical defects. Keywords: Optical distortion; Windscreen; Windshield; Canopy; Haze; Disparity; Birefringence; Angular deviation; Halation; Multiple imaging; Reflections; Defect; Optical; Distortion; Transparency; Aircraft; Delamination; Diffraction; Acrylic; Rainbowing; Crazing; Characteristics; Polycarbonate. (kt)
收起
摘要 :
To help VHA achieve Recovery Act contract award requirements and accountability, efficiency, and transparency objectives, we assessed the eCMS data that OAL&C uses to monitor VHA Recovery Act NRM contract awards. As of July 15, 2009, eCMS showed that VHA had awarded $46.5 million of the $1 billion in Recovery Act NRM funding provided by the President and Congress for the correction, replacement, upgrade, and modernization of existing infrastructure and utility systems at VHA medical centers. Our review examined eCMS data for Recovery Act NRM contract awards to determine if the awards complied with Recovery Act contracting requirements and objectives and related OMB and OAL&C Recovery Act implementation guidance....
展开
To help VHA achieve Recovery Act contract award requirements and accountability, efficiency, and transparency objectives, we assessed the eCMS data that OAL&C uses to monitor VHA Recovery Act NRM contract awards. As of July 15, 2009, eCMS showed that VHA had awarded $46.5 million of the $1 billion in Recovery Act NRM funding provided by the President and Congress for the correction, replacement, upgrade, and modernization of existing infrastructure and utility systems at VHA medical centers. Our review examined eCMS data for Recovery Act NRM contract awards to determine if the awards complied with Recovery Act contracting requirements and objectives and related OMB and OAL&C Recovery Act implementation guidance.
收起
摘要 :
To make an atom transparent at a given laser frequency, one applies a second laser whose frequency is equal to the difference of an otherwise empty state and the point in frequency space to which a probing laser is tuned. This typ...
展开
To make an atom transparent at a given laser frequency, one applies a second laser whose frequency is equal to the difference of an otherwise empty state and the point in frequency space to which a probing laser is tuned. This type of transparency exhibits an essential nonreciprocity where, though absorption and refractive index may be negated, the nonlinear susceptibilities and coefficients for stimulated and spontaneous remain unchanged. We believe that there may be a new regime of nonlinear optics with special properties as resonances are approached.
收起
摘要 :
We show that, in a two-stage model of monetary policy with stochastic policy targets and asymmetric information, the transparency regime chosen by the central bank does never coincide with the regime preferred by society. Independ...
展开
We show that, in a two-stage model of monetary policy with stochastic policy targets and asymmetric information, the transparency regime chosen by the central bank does never coincide with the regime preferred by society. Independent of society's endogenous choice of delegation, the central bank reveals its inflation target and conceals its output target. In contrast, society would prefer either transparency or opacity of both targets. As a conclusion, the choice of the transparency regime should be part of the optimal delegation solution.
收起
摘要 :
Rendering objects transparently gives additional insight in complex and overlapping structures. However, traditional techniques for the rendering of transparent objects such as alpha blending are not very well suited for the rende...
展开
Rendering objects transparently gives additional insight in complex and overlapping structures. However, traditional techniques for the rendering of transparent objects such as alpha blending are not very well suited for the rendering of multiple transparent objects in dynamic scenes. Screen-door transparency is a technique to render transparent objects in a simple and efficient way: No sorting is required and intersecting polygons can be handled without further preprocessing. With this technique, polygons are rendered through a mask - only where the mask is present, pixels are set. However, artifacts such as incorrect opacities and distracting patterns can easily occur if the masks are not carefully designed. In this paper, first the requirements on the masks are considered. Next, three algorithms are presented for the generation of pixel masks. One algorithm is designed for the creation of small (e.g., 4 x 4) masks. The other two algorithms can be used for the creation of larger masks (e.g., 32 x 32). For each of these algorithms results are presented and discussed.
收起
