63,616 research outputs found
Prototype Graphs for radiative Corrections to Polarized Chargino or Neutralino Production in Electron-Positron Annihilation
We present the contributions from all types of one-loop corrections to the
scattering amplitude for the pair production of polarized charginos or
neutralinos from polarized electron-positron annihilation. The contributions
are classified in terms of ``prototypes'' distinguished by the number of
particles inside the loops and their spins. The results are quoted in terms of
the Veltman-Passarino functions in terms of general couplings and internal
masses. The results can therefore be applied to any supersymmetric extension of
the Standard Model or indeed to any polarized fermion pair production process
in electron-positron annihilation.Comment: LATEX 38 pages, 26 figure
3-D Object Recognition by the ART-EMAP Evidence Accumulation Network
ART-EMAP synthesizes adaptive resonance theory (AHT) and spatial and temporal evidence integration for dynamic predictive mapping (EMAP). The network extends the capabilities of fuzzy ARTMAP in four incremental stages. Stage I introduces distributed pattern representation at a view category field. Stage 2 adds a decision criterion to the mapping between view and object categories, delaying identification of ambiguous objects when faced with a low confidence prediction. Stage 3 augments the system with a field where evidence accumulates in medium-term memory (MTM). Stage 4 adds an unsupervised learning process to fine-tune performance after the limited initial period of supervised network training. Simulations of the four ART-EMAP stages demonstrate performance on a difficult 3-D object recognition problem.Advanced Research Projects Agency (ONR N00014-92-J-4015); National Science Foundation (IRI-90-00530); Office of Naval Research (N00014-91-J-1309); Air Force Office of Scientific Research (90-0083
NLO Leptoquark Production and Decay: The Narrow-Width Approximation and Beyond
We study the leptoquark model of Buchm\"uller, R\"uckl and Wyler, focusing on
a particular type of scalar () and vector () leptoquark. The primary
aim is to perform the calculations for leptoquark production and decay at
next-to-leading order (NLO) to establish the importance of the NLO
contributions and, in particular, to determine how effective the
narrow-width-approximation (NWA) is at NLO. For both the scalar and vector
leptoquarks it is found that the NLO contributions are large, with the larger
corrections occurring for the case vector leptoquarks. For the scalar
leptoquark it is found that the NWA provides a good approximation for
determining the resonant peak, however the NWA is not as effective for the
vector leptoquark. For both the scalar and vector leptoquarks there are large
contributions away from the resonant peak, which are missing from the NWA
results, and these make a significant difference to the total cross-section.Comment: 22 pages, 17 figure
Borel singularities at small x
D.I.S. at small Bjorken is considered within the dipole cascade
formalism. The running coupling in impact parameter space is introduced in
order to parametrize effects that arise from emission of large size dipoles.
This results in a new evolution equation for the dipole cascade. Strong
coupling effects are analyzed after transforming the evolution equation in
Borel () space. The Borel singularities of the solution are discussed first
for the universal part of the dipole cascade and then for the specific process
of D.I.S. at small . In the latter case the leading infrared renormalon is
at indicating the presence of power corrections for the
small- structure functions.Comment: 5 pages, Latex (Talk presented at DIS'97, Chicago, IL
Optimal payload rate limit algorithm for zero-G manipulators
An algorithm for continuously computing safe maximum relative velocities for two bodies joined by a manipulator is discussed. The maximum velocities are such that if the brakes are applied at that instant, the ensuing travel between the bodies will be less than or equal to a predetermined amount. An improvement in the way this limit is computed for space manipulators is shown. The new method is explained, test cases are posed, and the results of these tests are displayed and discussed
Noise addendum experimental clean combustor program, phase 1
The development of advanced CTOL aircraft engines with reduced exhaust emissions is discussed. Combustor noise information provided during the basic emissions program and used to advantage in securing reduced levels of combustion noise is included. Results are presented of internal pressure transducer measurements made during the scheduled emissions test program on ten configurations involving variations of three basic combustor designs
Use of the metastatic breast cancer progression (MBC-P) questionnaire to assess the value of progression-free survival for women with metastatic breast cancer.
While overall survival (OS) has historically been the primary endpoint for clinical trials in oncology, progression-free survival (PFS) has gained acceptance as a valuable surrogate endpoint. However, there are no known published reports about the value of PFS from the patient's perspective. We developed a questionnaire that included items regarding quality of life (QoL) and the importance of different treatment outcomes and presented hypothetical scenarios for which respondents were asked to indicate their preferences concerning treatments as they relate to PFS. 282 women with metastatic breast cancer (MBC), ranging in age from 21 to 80 years completed an online version of this questionnaire. The majority of women (66 %) had been diagnosed with MBC within the previous 3 years and 56 % had been told their MBC had progressed. When asked to rank five treatment characteristics from most important to least important, respondents ranked "extending PFS" as the second most important treatment outcome after OS. When presented with a hypothetical scenario of two women receiving different treatments, respondents preferred the treatment that resulted in longer PFS (16 vs. 12 months), even when OS and side effects were assumed to be equal. Specifically, when asked to consider which woman within the hypothetical scenario had better QoL, physical functioning, and emotional well-being, respondents more often chose the woman who experienced longer PFS (QoL: 40 vs. 6 %; physical functioning: 32 vs. 8 %; emotional well-being: 58 vs. 6 %) compared to the woman within the hypothetical scenario who had a shorter time of progression. Respondents rated their own QoL highest after being told their MBC was responding to treatment (mean score 76.6) versus after the initial diagnosis of breast cancer and MBC (68.5 and 60.3). These findings suggest that extending PFS is an important treatment outcome and, from a patient perspective, improves overall QoL, physical functioning, and emotional well-being
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Number of Pages: 17Integrative BiologyGeological Science
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