6,911 research outputs found
Anomalous resonant production of the fourth family up type quarks at the LHC
Considering the present limits on the masses of fourth family quarks from the
Tevatron experiments, the fourth family quarks are expected to have mass larger
than the top quark. Due to their expected large mass they could have different
dynamics than the quarks of three families of the Standard Model. The resonant
production of the fourth family up type quark t' has been studied via anomalous
production subprocess gq_i-->t' (where q_i=u,c) at the LHC with the center of
mass energy 10 TeV and 14 TeV. The signatures of such process are discussed
within the SM decay modes. The sensitivity to anomalous coupling
\kappa/\Lambda=0.1 TeV^(-1) can be reached at \sqrt{s}=10 TeV and L_int=100
pb^(-1).Comment: 14 pages, 13 figures, 7 table
Analyzing relationships between student mobility and value-added gain-scores in East Tennessee elementary schools
The purpose of this study was to examine the relationship between student mobility and Value-Added gain-scores in East Tennessee elementary schools. One large school district was selected as the population; forty-seven elementary schools were included in the analysis. Tennesse·e Value-Added Assessment System (TV AAS) gain-scores in Language Arts, Math, and Reading for grades three, four, and five were analyzed. While it cannot be stated that mobility is a causal factor in poor student achievement, this study supported previous research that found that mobility was a contributing factor associated with poor student achievement. A Pearson\u27s Correlation Coefficient Test revealed that composite Federal Free/Reduced Lunch percentages displayed a stronger relationship with lower value-added gain-scores than student mobility rate percentages. However, the two variables closely overlap in the analysis. Findings also revealed that when mobile students were removed from the Pearson\u27s Correlation Coefficient analysis, value-added gain-scores in Language Arts and Math increased at thirty-four schools. Nineteen school value-added gain-scores increased in Reading. The system-wide average score increase for each school represented in the study was .50. Only Math value-added gain-scores were statistically significant (R = .43) when mobile student scores were removed from the Pearson\u27s analysis; Alpha was set at the .05 level of significance. Recommendations for classroom, school, district, and state level strategies to counteract the negative impact of student mobility are provided as well as recommendations for further study
Block to granular-like transition in dense bubble flows
We have experimentally investigated 2-dimensional dense bubble flows
underneath inclined planes. Velocity profiles and velocity fluctuations have
been measured. A broad second-order phase transition between two dynamical
regimes is observed as a function of the tilt angle . For low
values, a block motion is observed. For high values, the velocity
profile becomes curved and a shear velocity gradient appears in the flow.Comment: Europhys. Lett. (2003) in pres
Parabolic dunes in north-eastern Brazil
In this work we present measurements of vegetation cover over parabolic dunes
with different degree of activation along the north-eastern Brazilian coast. We
are able to extend the local values of the vegetation cover density to the
whole dune by correlating measurements with the gray-scale levels of a high
resolution satellite image of the dune field. The empirical vegetation
distribution is finally used to validate the results of a recent continuous
model of dune motion coupling sand erosion and vegetation growth.Comment: 18 pages, 14 figures, aubmitted to Geomorpholog
Fast Hierarchical Clustering and Other Applications of Dynamic Closest Pairs
We develop data structures for dynamic closest pair problems with arbitrary
distance functions, that do not necessarily come from any geometric structure
on the objects. Based on a technique previously used by the author for
Euclidean closest pairs, we show how to insert and delete objects from an
n-object set, maintaining the closest pair, in O(n log^2 n) time per update and
O(n) space. With quadratic space, we can instead use a quadtree-like structure
to achieve an optimal time bound, O(n) per update. We apply these data
structures to hierarchical clustering, greedy matching, and TSP heuristics, and
discuss other potential applications in machine learning, Groebner bases, and
local improvement algorithms for partition and placement problems. Experiments
show our new methods to be faster in practice than previously used heuristics.Comment: 20 pages, 9 figures. A preliminary version of this paper appeared at
the 9th ACM-SIAM Symp. on Discrete Algorithms, San Francisco, 1998, pp.
619-628. For source code and experimental results, see
http://www.ics.uci.edu/~eppstein/projects/pairs
A taxonomic study of the genus Fibigia Medik. (Brassicaceae)
In this study, Purpureae A.Duran and Ö.Çetin sect. nov. is described under the genus Fibigia Medik. The taxa of the genus were revised under the sections Fibigia and Purpureae. Fibigia clypeata (L.) Medik was classified as F. clypeata (L.) Medik subsp. clypeata and subsp. anatolica A.Duran & Tustas subsp. nov., and Fibigia eriocarpa (DC.) Boiss. was rearranged as F. clypeata (L.) Medik subsp. clypeata var. eriocarpa in Turkish Flora. The infrageneric and subgeneric keys were revised. Seed and pollen surface ornamentations were studied by scanning electron microscopy (SEM). The pollens examined have tricolpate aperture type and reticulate surface ornamentation. Seed surface ornamentation was reticulate. The taxa of the genus Fibigia have a diploid chromosome number of 2n=16. Karyotype analyses of the taxa were carried out for the first time. It was found that each taxon differed in chromosome morphology.Key words: Fibigia, morphology, pollen, scanning electron microscopy (SEM), new taxa, Turkey
AS-826-17 Resolution to Establish Exit Interview Protocol, and a Request for Outside Review
Request that administration develops a protocol for all permanent employee
Solidarity Art / Arte Solidario
Bilingual poem and image
Minimizing engine emissions using state-feedback control with LQR and artificial intelligence fuel estimator
This paper presents a novel engine controller targeting the reduction of gas emissions. Toxic emissions, such as Carbon Monoxide (CO) and Nitric Oxide (NOx) affect the environment and the authorities aim to limit their amount by law. Emissions are formed during the high temperature combustion process, and can be optimised by adjusting some engine operating parameters. In this paper, the model describing emissions output of the engine as a function of engine control parameters is represented as a state-space system. A closed-loop controller is developed by using statefeedback control algorithm. The closed-loop gain, K, is obtained from the LQR tuning principles. The fuel estimator developed in previous works is used in order to reduce the model from the 8th order. The results show that the controller is able to control emission to the minimum in all constraints while keeping engine running in the same performance
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