749 research outputs found
CP Phases in Supersymmetric Tri-lepton Signals at the Tevatron
We have analyzed the supersymmetric tri-lepton signals for sparticle searches
at the Tevatron in the minimal supersymmetric standard model with general CP
phases without generational mixing. The CP phases may affect very strongly the
chargino and neutralino mass spectrums and
as well as and . Even under the stringent
constraints from the electron electric dipole moment the CP phases can lead to
a minimum of the tri-lepton event rate for their non-trivial values.Comment: 10 pages, 3 eps figures, largely revised by including the electron
EDM constraint
Stock portfolio selection using learning-to-rank algorithms with news sentiment
In this study, we apply learning-to-rank algorithms to design trading strategies
using relative performance of a group of stocks based on investors' sentiment
toward these stocks. We show that learning-to-rank algorithms are effective in
producing reliable rankings of the best and the worst performing stocks based
on investors' sentiment. More specifically, we use the sentiment shock and trend
indicators introduced in the previous studies, and we design stock selection rules
of holding long positions of the top 25% stocks and short positions of the bottom
25% stocks according to rankings produced by learning-to-rank algorithms.
We then apply two learning-to-rank algorithms, ListNet and RankNet, in stock
selection processes and test long-only and long-short portfolio selection strategies
using 10 years of market and news sentiment data. Through backtesting of
these strategies from 2006 to 2014, we demonstrate that our portfolio strategies
produce risk-adjusted returns superior to the S&P500 index return, the hedge
fund industry average performance - HFRIEMN, and some sentiment-based approaches
without learning-to-rank algorithm during the same period
A Critical Analysis Of The State-Of-The-Art On Automated Detection Of Deceptive Behavior In Social Media
Recently, a large body of research has been devoted to examine the user behavioral patterns and the business implications of social media. However, relatively little research has been conducted regarding users’ deceptive activities in social media; these deceptive activities may hinder the effective application of the data collected from social media to perform e-marketing and initiate business transformation in general. One of the main contributions of this paper is the critical analysis of the possible forms of deceptive behavior in social media and the state-of-the-art technologies for automated deception detection in social media. Based on the proposed taxonomy of major deception types, the assumptions, advantages, and disadvantages of the popular deception detection methods are analyzed. Our critical analysis shows that deceptive behavior may evolve over time, and so making it difficult for the existing methods to effectively detect social media spam. Accordingly, another main contribution of this paper is the design and development of a generic framework to combat dynamic deceptive activities in social media. The managerial implication of our research is that business managers or marketers will develop better insights about the possible deceptive behavior in social media before they tap into social media to collect and generate market intelligence. Moreover, they can apply the proposed adaptive deception detection framework to more effectively combat the ever increasing and evolving deceptive activities in social medi
Finite Temperature Many-Body Theory with the Lipkin Model
We have compared exact numerical results for the Lipkin model at finite
temperature with Hartree-Fock theory and with the results of including in
addition the ring diagrams. In the simplest version of the Lipkin model the
Hartree-Fock approach shows a ``phase transition" which is absent in the exact
results. For more realistic cases, Hartree-Fock provides a very good
approximation and a modest improvement is obtained by adding the ring diagrams.Comment: 17 pages, NUC-MINN-93/16-T (4 figures obtainable by fax from the
authors
Evaluation of fermented whole crop wheat and barley feeding on growth performance, nutrient digestibility, faecal volatile fatty acid emission, blood constituents, and faecal microbiota in growing pigs
This study was conducted to determine the effects of feeding diets with fermented whole crop wheat (FWW) and fermented whole crop barley (FWB) on growth performance, nutrient digestibility, blood constituents, faecal volatile fatty acid (VFA) emission and faecal microbiota in growing pigs. A total of 200 growing pigs were randomly allotted to five treatments with eight replicates per treatment and five pigs per replicate. Dietary treatments consisted of i) CON (basal diet), ii) 0.5% FWW (CON + 0.5% fermented whole crop wheat), iii) 1.0% FWW (CON + 1.0% fermented whole crop wheat), iv) 0.5% FWB (CON + 0.5% fermented whole crop barley), and v) 1.0% FWB (CON + 1.0% fermented whole crop barley). The digestibility of total dietary fibre was significantly higher in pigs fed FWW diets. The faecal emissions of VFA of pigs fed the fermented treatments was increased significantly compared with CON. Concentrations of cortisol and triglyceride in blood of pigs fed 1.0% FWW were significantly lower than pigs fed CON diets. The pigs fed 1.0% FWB diets had a significantly decreased level of total cholesterol in blood compared with CON. In conclusion, the current results indicated that diets supplemented with FWW and FWB could increase faecal VFA emission and reduce concentration of triglyceride and cortisol, while 0.5% and 1.0% FWW had no negative effects on growth performance, and could increase digestibility of dietary fibre in growing pigs.Keywords:Â Dietary fibre, faecal short-chain fatty acid emissions, fermented feed, serum parameter, swin
Bouncing Universe with Quintom Matter
The bouncing universe provides a possible solution to the Big Bang
singularity problem. In this paper we study the bouncing solution in the
universe dominated by the Quintom matter with an equation of state (EoS)
crossing the cosmological constant boundary. We will show explicitly the
analytical and numerical bouncing solutions in three types of models for the
Quintom matter with an phenomenological EoS, the two scalar fields and a scalar
field with a modified Born-Infeld action.Comment: 7 pages, 5 figure
EGAM Induced by Energetic-electrons and Nonlinear Interactions among EGAM, BAEs and Tearing Modes in a Toroidal Plasma
In this letter, it is reported that the first experimental results are
associated with the GAM induced by energetic electrons (eEGAM) in HL-2A Ohmic
plasma. The energetic-electrons are generated by parallel electric fields
during magnetic reconnection associated with tearing mode (TM). The eEGAM
localizes in the core plasma, i.e. in the vicinity of q=2 surface, and is very
different from one excited by the drift-wave turbulence in the edge plasma. The
analysis indicated that the eEGAM is provided with the magnetic components,
whose intensities depend on the poloidal angles, and its mode numbers are
jm/nj=2/0. Further, there exist intense nonlinear interactions among eEGAM,
BAEs and strong tearing modes (TMs). These new findings shed light on the
underlying physics mechanism for the excitation of the low frequency (LF)
Alfv\'enic and acoustic uctuations.Comment: 5 pages,4 figure
CP Phases in Correlated Production and Decay of Neutralinos in the Minimal Supersymmetric Standard Model
We investigate the associated production of neutralinos
accompanied by the neutralino
leptonic decay , taking into
account initial beam polarization and production-decay spin correlations in the
minimal supersymmetric standard model with general CP phases but without
generational mixing in the slepton sector. The stringent constraints from the
electron EDM on the CP phases are also included in the discussion. Initial beam
polarizations lead to three CP--even distributions and one CP--odd
distribution, which can be studied independently of the details of the
neutralino decays. We find that the production cross section and the branching
fractions of the leptonic neutralino decays are very sensitive to the CP
phases. In addition, the production--decay spin correlations lead to several
CP--even observables such as lepton invariant mass distribution, and lepton
angular distribution, and one interesting T--odd (CP--odd) triple product of
the initial electron momentum and two final lepton momenta, the size of which
might be large enough to be measured at the high--luminosity future
electron--positron collider or can play a complementary role in constraining
the CP phases with the EDM constraints.Comment: Revtex, 37 pages, 12 eps figure
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