6,079 research outputs found
Unification without low-energy supersymmetry
Without supersymmetry, the gauge couplings in the standard model with five
Higgs doublets unify around 10^14 GeV. In this case, the trinified model,
SU(3)_C x SU(3)_L x SU(3)_R x Z_3, with the minimal Higgs sector required for
symmetry breaking, is the ideal grand-unified candidate. Small neutrino masses
are generated via a radiative seesaw mechanism, without the need for
intermediate scales, additional Higgs fields, or higher-dimensional operators.
The proton lifetime is above the experimental limits, with the decay modes p ->
\bar\nu K^+ and p -> mu^+ K^0 potentially observable. The split-SUSY version of
the model, with one light Higgs doublet, is equally attractive.Comment: To appear in Proceedings of SUSY06, the 14th International Conference
on Supersymmetry and the Unification of Fundamental Interactions, UC Irvine,
California, 12-17 June 200
Distributed Remote Vector Gaussian Source Coding for Wireless Acoustic Sensor Networks
In this paper, we consider the problem of remote vector Gaussian source
coding for a wireless acoustic sensor network. Each node receives messages from
multiple nodes in the network and decodes these messages using its own
measurement of the sound field as side information. The node's measurement and
the estimates of the source resulting from decoding the received messages are
then jointly encoded and transmitted to a neighboring node in the network. We
show that for this distributed source coding scenario, one can encode a
so-called conditional sufficient statistic of the sources instead of jointly
encoding multiple sources. We focus on the case where node measurements are in
form of noisy linearly mixed combinations of the sources and the acoustic
channel mixing matrices are invertible. For this problem, we derive the
rate-distortion function for vector Gaussian sources and under covariance
distortion constraints.Comment: 10 pages, to be presented at the IEEE DCC'1
Distributed Remote Vector Gaussian Source Coding with Covariance Distortion Constraints
In this paper, we consider a distributed remote source coding problem, where
a sequence of observations of source vectors is available at the encoder. The
problem is to specify the optimal rate for encoding the observations subject to
a covariance matrix distortion constraint and in the presence of side
information at the decoder. For this problem, we derive lower and upper bounds
on the rate-distortion function (RDF) for the Gaussian case, which in general
do not coincide. We then provide some cases, where the RDF can be derived
exactly. We also show that previous results on specific instances of this
problem can be generalized using our results. We finally show that if the
distortion measure is the mean squared error, or if it is replaced by a certain
mutual information constraint, the optimal rate can be derived from our main
result.Comment: This is the final version accepted at ISIT'1
Recent trends related to the use of formal methods in software engineering
An account is given of some recent developments and trends related to the development and use of formal methods in software engineering. Ongoing activities in Europe are focussed on, since there seems to be a notable difference in attitude towards industrial usage of formal methods in Europe and in the U.S. A more detailed account is given of the currently most widespread formal method in Europe: the Vienna Development Method. Finally, the use of Ada is discussed in relation to the application of formal methods, and the potential for constructing Ada-specific tools based on that method is considered
The Debt Ratio and Risk
The agricultural development has caused still bigger and more expensive farms in Denmark. The debt ratio therefore has increased and has become a severe problem for the farmer. The magnitude of the debt ratio is the highest in Europe. The objective of this study is to analyse the possibility to optimise the debt ratio. In order to analyse the debt ratio 1200 financial statements have been investigated. The study confirms that it is impossible to optimise the debt ratio in line with Modigliani & Miller. On the other hand the study points out an inoptimal range, which is in accordance with the 'Trade-off Theory of Capital Structure'. That is on the high end of the scale. Finally the study demonstrates a significant correlation between the debt ratio and the financial risk.Agricultural Finance, Risk and Uncertainty,
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