138 research outputs found
Estimation of streamflow by slope Regional Dependency Function
International audienceKriging is one of the most developed methodologies in the regional variable modeling. However, one of its drawbacks is that the influence radius can not be determined by this method. In which distance and in what ratio that pivot station is influenced from adjacent sites is rather often encountered problem in practical applications. Regional weighting functions obtained from available data consist of several broken lines. Each line has different slopes which represent the similarity and the contribution of adjacent stations as a weighting coefficient. The approach in this study is called as Slope Regional Dependency Function (SRDF). The main idea of this approach is to express the variability in value differences [?(d)] and distances together. Originally proposed SRDF and Trigonometric Point Cumulative Semi-Variogram (TPCSV) methods are used to predict streamflow. Also TPCSV and Point Cumulative Semi-Variogram (PCSV) approaches are compared with each other. Prediction performance of all three methods stays below 10% relative error which is acceptable for the engineering applications. It is shown that SRDF outperforms PCSV and TPCSV with very high differences. It can be used for missing data completion, determination of measurement sites location, calculation of influence radius, and determination of regional variable potential. The proposed method is applied for the 38 stream flow measurement sites located in the Mississippi River basin
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Fuzzy logic-based attenuation relationships of strong motion earthquake records
Fuzzy logic techniques have been widely used in civil and earthquake engineering applications in the past four decades. However, no thorough research studies were conducted to use them for deriving attenuation relationships for peak ground accelerations (PGA). This paper is an attempt to fill this gap by employing a fuzzy approach with fuzzy sets for earthquake magnitude and distance from source with the objective of proposing new ground motion attenuation models. Recent earthquake records from USA and Taiwan with magnitudes 5 or greater were used; and consisted of horizontal peak ground acceleration recorded on three different site conditions: rock, soil and soft soil. The use of Fuzzy models to quantify ground motion records, which are typically characterized by a high level of uncertainty, leads to a rational analytical tool capable of predicting accurate results. Testing of the fuzzy model with an independent data set confirmed its accuracy in predicting PGA values
Finitely Many Dirac-Delta Interactions on Riemannian Manifolds
This work is intended as an attempt to study the non-perturbative
renormalization of bound state problem of finitely many Dirac-delta
interactions on Riemannian manifolds, S^2, H^2 and H^3. We formulate the
problem in terms of a finite dimensional matrix, called the characteristic
matrix. The bound state energies can be found from the characteristic equation.
The characteristic matrix can be found after a regularization and
renormalization by using a sharp cut-off in the eigenvalue spectrum of the
Laplacian, as it is done in the flat space, or using the heat kernel method.
These two approaches are equivalent in the case of compact manifolds. The heat
kernel method has a general advantage to find lower bounds on the spectrum even
for compact manifolds as shown in the case of S^2. The heat kernels for H^2 and
H^3 are known explicitly, thus we can calculate the characteristic matrix.
Using the result, we give lower bound estimates of the discrete spectrum.Comment: To be published in JM
Temporal significant wave height estimation from wind speed by perceptron Kalman filtering
The significant wave heights and periods are conventionally forecasted from the wind information on the basis of the wind-wave relationship. However, the error may become large due to many uncertainties in the wind generation prediction and wind-wave relationship. This is also confirmed by the authors, where the correlation (r) between measured wind speeds and significant wave heights is found to be 0.595 (r 2 = 0.3541). The authors have rightly mentioned the restrictive uses of regression method, especially for predicting wind generated waves. The authors have established the two layered Perceptron based on Kalman Interestingly the PKF model is a two layered network (input and output) without hidden layer. Also it is a fact that numerical or physical models have restrictions by certain assumptions and conditions, whereas artificial neural network (ANN) ha
When Anomaly Mediation is UV Sensitive
Despite its successes---such as solving the supersymmetric flavor
problem---anomaly mediated supersymmetry breaking is untenable because of its
prediction of tachyonic sleptons. An appealing solution to this problem was
proposed by Pomarol and Rattazzi where a threshold controlled by a light field
deflects the anomaly mediated supersymmetry breaking trajectory, thus evading
tachyonic sleptons. In this paper we examine an alternate class of deflection
models where the non-supersymmetric threshold is accompanied by a heavy,
instead of light, singlet. The low energy form of this model is the so-called
extended anomaly mediation proposed by Nelson and Weiner, but with potential
for a much higher deflection threshold. The existence of this high deflection
threshold implies that the space of anomaly mediated supersymmetry breaking
deflecting models is larger than previously thought.Comment: 14 pages, 1 figure (version to appear in JHEP
F-Theory Grand Unification at the Colliders
We predict the exact gaugino mass relation near the electroweak scale at one
loop for gravity mediated supersymmetry breaking in F-theory SU(5) and SO(10)
models with U(1)_Y and U(1)_{B-L} fluxes, respectively. The gaugino mass
relation introduced here differs from the typical gaugino mass relations
studied thus far, and in general, should be preserved quite well at low energy.
Therefore, these F-Theory models can be tested at the Large Hadron Collider and
future International Linear Collider. We present two typical scenarios that
satisfy all the latest experimental constraints and are consistent with the
CDMS II experiment. In particular, the gaugino mass relation is indeed
satisfied at two-loop level with only a very small deviation around the
electroweak scale.Comment: RevTex4, 6 pages, 6 figure
High Scale Physics Connection to LHC Data
The existing data appears to provide hints of an underlying high scale
theory. These arise from the gauge coupling unification, from the smallness of
the neutrino masses, and via a non-vanishing muon anomaly. An overview of high
scale models is given with a view to possible tests at the Large Hadron
Collider. Specifically we discuss here some generic approaches to deciphering
their signatures. We also consider an out of the box possibility of a four
generation model where the fourth generation is a mirror generation rather than
a sequential generation. Such a scenario can lead to some remarkably distinct
signatures at the LHC.Comment: 23 pages, no figures. Based on invited lectures at the 46th Course at
the International School of Subnuclear Physics- Erice -Sicily: 29 August -7
September, 200
Fine-tuning implications for complementary dark matter and LHC SUSY searches
The requirement that SUSY should solve the hierarchy problem without undue
fine-tuning imposes severe constraints on the new supersymmetric states. With
the MSSM spectrum and soft SUSY breaking originating from universal scalar and
gaugino masses at the Grand Unification scale, we show that the low-fine-tuned
regions fall into two classes that will require complementary collider and dark
matter searches to explore in the near future. The first class has relatively
light gluinos or squarks which should be found by the LHC in its first run. We
identify the multijet plus E_T^miss signal as the optimal channel and determine
the discovery potential in the first run. The second class has heavier gluinos
and squarks but the LSP has a significant Higgsino component and should be seen
by the next generation of direct dark matter detection experiments. The
combined information from the 7 TeV LHC run and the next generation of direct
detection experiments can test almost all of the CMSSM parameter space
consistent with dark matter and EW constraints, corresponding to a fine-tuning
not worse than 1:100. To cover the complete low-fine-tuned region by SUSY
searches at the LHC will require running at the full 14 TeV CM energy; in
addition it may be tested indirectly by Higgs searches covering the mass range
below 120 GeV.Comment: References added. Version accepted for publication in JHE
Phenomenological Implications of Deflected Mirage Mediation: Comparison with Mirage Mediation
We compare the collider phenomenology of mirage mediation and deflected
mirage mediation, which are two recently proposed "mixed" supersymmetry
breaking scenarios motivated from string compactifications. The scenarios
differ in that deflected mirage mediation includes contributions from gauge
mediation in addition to the contributions from gravity mediation and anomaly
mediation also present in mirage mediation. The threshold effects from gauge
mediation can drastically alter the low energy spectrum from that of pure
mirage mediation models, resulting in some cases in a squeezed gaugino spectrum
and a gluino that is much lighter than other colored superpartners. We provide
several benchmark deflected mirage mediation models and construct model lines
as a function of the gauge mediation contributions, and discuss their discovery
potential at the LHC.Comment: 29 pages, 9 figure
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