6,315 research outputs found
A tracker alignment framework for augmented reality
To achieve accurate registration, the transformations which locate the tracking system components with respect to the environment must be known. These transformations relate the base of the tracking system to the virtual world and the tracking system's sensor to the graphics display. In this paper we present a unified, general calibration method for calculating these transformations. A user is asked to align the display with objects in the real world. Using this method, the sensor to display and tracker base to world transformations can be determined with as few as three measurements
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Engineering of nano-microscale lamellae in a model collagen-based scaffold
Zeroing in on more photons and gluons
We discuss radiation zeros that are found in gauge tree amplitudes for
processes involving multi-photon emission. Previous results are clarified by
examples and by further elaboration. The conditions under which such amplitude
zeros occur are identical in form to those for the single-photon zeros, and all
radiated photons must travel parallel to each other. Any other neutral particle
likewise must be massless (e.g. gluon) and travel in that common direction. The
relevance to questions like gluon jet identification and computational checks
is considered. We use examples to show how certain multi-photon amplitudes
evade the zeros, and to demonstrate the connection to a more general result,
the decoupling of an external electromagnetic plane wave in the ``null zone".
Brief comments are made about zeros associated with other gauge-boson emission.Comment: 26 page
Imaging Sources with Fast and Slow Emission Components
We investigate two-proton correlation functions for reactions in which fast
dynamical and slow evaporative proton emission are both present. In such cases,
the width of the correlation peak provides the most reliable information about
the source size of the fast dynamical component. The maximum of the correlation
function is sensitive to the relative yields from the slow and fast emission
components. Numerically inverting the correlation function allows one to
accurately disentangle fast dynamical from slow evaporative emission and
extract details of the shape of the two-proton source.Comment: 13 pages, 4 figure
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The Energy-Related Inventions Program: Evaluation challenges and solutions
This paper describes results of evaluation of the Energy-Related Inventions Program (ERIP), focusing on the methodological challenges faced by the evaluators and solutions implemented. Operated jointly by US DOE and NIST, ERIP is one of the longest running commercialization assistance programs in US. The evaluation suggest that ERIP is a cost-effective federal investment. By the end of 1994, 24% of ERIP technologies had entered the market, producing total cumulative sales of 124 million in program appropriations 1975-94, ERIP has an 8:1 return. At least 757 job-years were directly supported by ERIP technologies in 1994, and 6, 646 job-years of employment have been created over the past decade. The sales and employment supported by ERIP technologies are associated with $4.4 million in 1994 federal tax returns. Many issues must be addressed to fairly appraise public investments in technology commercialization programs, such as the need to track the program participants for extended periods, complexities in accounting for spinoff technologies, determining the validity of program evaluations, and dealing with performance data that are dominated by a small number of highly successful technologies
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Energy-efficient buildings: Does the marketplace work?
For a variety of reasons, U.S. households, businesses, manufacturers, and government agencies all fail to take full advantage of cost-effective, energy-efficiency opportunities. Despite a growing environmental ethic among Americans and a concern for energy independence, consumers in this country are underinvesting in technologies, products, and practices that would cut their energy bills. The result is a large untapped potential for improving energy productivity, economic competitiveness, environmental quality, and energy security. The thesis of this paper is that the marketplace for energy efficiency, in general, is not operating perfectly, and the marketplace for energy-efficient buildings, in particular, is flawed. The reasons for underinvestments in cost-effective, energy efficiency are numerous and complicated. They also vary from sector to sector: the principal causes of energy inefficiencies in agriculture, manufacturing, and transportation are not the same as the causes of inefficiencies in homes and office buildings, although there are some similarities. One of the reasons for these differences is that the structure of marketplace for delivering new technologies and products in each sector differs. Energy-efficiency improvements in the buildings sector is critical to reducing greenhouse gas emissions, since most of the energy consumed in buildings comes from the burning of fossil fuels. This paper therefore begins by describing energy use and energy trends in the U.S. buildings sector. Characteristics of the marketplace for delivering energy efficiency technologies and products are then described in detail, arguing that this marketplace structure significantly inhibits rapid efficiency improvements
Sodium dependent inositol transport in HL60 cells is not related to Na+/K+, ATPase activity
AbstractIn HL60 cells, inositol transport is sodium-dependent but functionally independent of Na+/K+ ATPase activity. This observation has implications for the currently proposed theory for the development of diabetic complications
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Our Blood will be Avenged Before the LordâNoble Death in the Assumption of Moses
This thesis examines the narrative of Taxo and his sons in the Assumption of Moses (As. Mos.) through the framework of âJewish Noble Death.â There has been a tendency among scholars searching to reconstruct the early employment of martyr narratives in Jewish and Christian literatureânarratives which depict the martyr making the decision to die a voluntary death rather than renounce their faithâto deny or dismiss the relevance of As. Mos. for understanding the development of antique martyrology. Where it has been included in such surveys of early martyrdom, important details about the textâs context and possible social function have been overlooked. It is my contention that this short but complex text may convey how ideas about piety and oneâs willingness to die because of commitment to the Law shaped early Jewish identity in a period of great social, religious, and cultural change. As. Mos. reflects a stage in the development of the connection between noble death and posthumous, divine reward, and religious mandate in the study of the early martyrological tradition, and the contribution of this text merits consideration. It advocates for continued adherence to, and preservation of, ancestral Law, even to the point of deathânot only in the face of foreign imperialism and pagan persecution but also in the face of priestly impiety and corruption internal to Jewish society. As. Mos. constructs the deaths of Taxo and his sons, a full expression of their piety and obedience, as an antitype to contemporary Jewish militant movements; where militancy has failed, Taxo and his sons will succeed. While the text shares common motifs with Second Temple works such as 2 Maccabees and the writings of Josephus, particularly in its depiction of familial martyrdom, the image of Jewishness in the first century CE depicted in As. Mos. is significant in its own right as an early example of how noble death and divine reward could be integrated with Jewish identity, without recourse to militancy.Religious Studie
Spatial Degrees of Freedom in Everett Quantum Mechanics
Stapp claims that, when spatial degrees of freedom are taken into account,
Everett quantum mechanics is ambiguous due to a "core basis problem." To
examine an aspect of this claim I generalize the ideal measurement model to
include translational degrees of freedom for both the measured system and the
measuring apparatus. Analysis of this generalized model using the Everett
interpretation in the Heisenberg picture shows that it makes unambiguous
predictions for the possible results of measurements and their respective
probabilities. The presence of translational degrees of freedom for the
measuring apparatus affects the probabilities of measurement outcomes in the
same way that a mixed state for the measured system would. Examination of a
measurement scenario involving several observers illustrates the consistency of
the model with perceived spatial localization of the measuring apparatus.Comment: 34 pp., no figs. Introduction, discussion revised. Material
tangential to main point remove
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