86,356 research outputs found

    Energy Positivity, Non-Renormalization, and Holomorphy in Lorentz-Violating Supersymmetric Theories

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    This paper shows that the positive-energy and non-renormalization theorems of traditional supersymmetry survive the addition of Lorentz violating interactions. The Lorentz-violating coupling constants in theories using the construction of Berger and Kostelecky must obey certain constraints in order to preserve the positive energy theorem. Seiberg's holomorphic arguments are used to prove that the superpotential remains non-renormalized (perturbatively) in the presence of Lorentz-violating interactions of the Berger-Kostelecky type. We briefly comment on Lorentz-violating theories of the type constructed by Nibbelink and Pospelov to note that holomorphy arguments offer elegant proofs of many non-renormalization results, some known by other arguments, some new.Comment: v3: Discussion and clarification added. References added. Results on gauge-kinetic function expande

    Vestibular-visual interactions in flight simulators

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    All 139 research papers published under this ten-year program are listed. Experimental work was carried out at the Ames Research Center involving man's sensitivity to rotational acceleration, and psychophysical functioning of the semicircular canals; vestibular-visual interactions and effects of other sensory systems were studied in flight simulator environments. Experiments also dealt with the neurophysiological vestibular functions of animals, and flight management investigations of man-vehicle interactions

    Factors influencing the perception of angular acceleration in man Semiannual status report

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    Human perception of angular acceleration during and after rotatio

    A Minimal Poset Resolution of Stable Ideals

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    We use the theory of poset resolutions to construct the minimal free resolution of an arbitrary stable monomial ideal in the polynomial ring whose coefficients are from a field. This resolution is recovered by utilizing a poset of Eliahou-Kervaire admissible symbols associated to a stable ideal. The structure of the poset under consideration is quite rich and in related analysis, we exhibit a regular CW complex which supports a minimal cellular resolution of a stable monomial ideal.Comment: 25 pages, 2 figure

    Unionization, Management Adjustment and Productivity

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    The effect of unionization on productivity is examined in this paper using time-series data on selected establishments in the U.S. cement industry. The analysis combines statistical estimation of the union impact and interviews with union and management officials to forge a link between econometric estimation and the traditional institutional analysis of union policy and management adjustment. The econometric analysis primarily deals with the problem of identifying the impact of the union in the face of firm specific effects and adjustments in labor quality. The case studies are designed to shed light on the question of how unionization affects productivity. The empirical results support the conclusion that unionization leads to productive changes in the operation of the enterprise. Evidence from the case studies suggests that much of the gain in productivity derives from a series of extensive changes in management personnel and procedure. These adjustments are a management response to changes in the employment contract which follow unionization.

    LANDSAT 3 return beam vidicon response artifacts: A report on RBV photographic product characteristics and quality coding system

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    Analysis of large volumes of LANDSAT 3 RBV digital data that were converted to photographic form led to the firm identification of several visible artifacts (objects or structures not normally present, but producted by an external agency or action) in the imagery. These artifacts were identified, categorized, and traced directly to specific sensor response characteristics. None of these artifacts is easily removed and all cases remain under active study of possible future enhancement. The seven generic categories of sensor response artifacts identified to date include: (1) shading and stairsteps; (2) corners out of focus; (3) missing reseaus; (4) reseau distortion and data distortion; (5) black vertical line; (6) grain effect; and (7) faceplate contamination. An additional category under study, but not yet determined to be caused by sensor response, is a geometric anomaly. Examples of affected imagery are presented to assist in distinguishing between image content and innate defects caused by the sensor system
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