129,414 research outputs found
Web-based information systems development and dynamic organisational change: the need for emergent development tools
This paper considers contextual issues relating to the problem of developing web-based information
systems in and for emergent organisations. It postulates that the methods available suffer because of
sudden and unexpected changing characteristics within the organisation. The Theory of Deferred
Action is used as the basis for the development of an emergent development tool. Many tools for
managing change in a continuously changing organisation are susceptible to inadequacy. The insights
proposed are believed to assist designers in developing functional and relevant approaches within
dynamic organisational contexts
Revisiting lepton flavor violation in supersymmetric type II seesaw
In view of the recent measurement of reactor mixing angle and
updated limit on by the MEG experiment, we re-examine
the charged lepton flavor violations in a framework of supersymmetric type II
seesaw mechanism. Supersymmetric type II seesaw predicts strong correlation
between and mainly in terms of
the neutrino mixing angles. We show that such a correlation can be determined
accurately after the measurement of . We compute different factors
which can affect this correlation and show that the mSUGRA-like scenarios, in
which slepton masses are taken to be universal at the high scale, predicts for normal
hierarchical neutrino masses. Any experimental indication of deviation from
this prediction would rule out the minimal models of supersymmetric type II
seesaw. We show that the current MEG limit puts severe constraints on the light
sparticle spectrum in mSUGRA model if the seesaw scale lies within
- GeV. It is shown that these constraints can be relaxed and
relatively light sparticle spectrum can be obtained in a class of models in
which the soft mass of triplet scalar is taken to be non-universal at the high
scale.Comment: Minor changes in text; accepted for publication in Phys. Rev.
C2AE: Class Conditioned Auto-Encoder for Open-set Recognition
Models trained for classification often assume that all testing classes are
known while training. As a result, when presented with an unknown class during
testing, such closed-set assumption forces the model to classify it as one of
the known classes. However, in a real world scenario, classification models are
likely to encounter such examples. Hence, identifying those examples as unknown
becomes critical to model performance. A potential solution to overcome this
problem lies in a class of learning problems known as open-set recognition. It
refers to the problem of identifying the unknown classes during testing, while
maintaining performance on the known classes. In this paper, we propose an
open-set recognition algorithm using class conditioned auto-encoders with novel
training and testing methodology. In contrast to previous methods, training
procedure is divided in two sub-tasks, 1. closed-set classification and, 2.
open-set identification (i.e. identifying a class as known or unknown). Encoder
learns the first task following the closed-set classification training
pipeline, whereas decoder learns the second task by reconstructing conditioned
on class identity. Furthermore, we model reconstruction errors using the
Extreme Value Theory of statistical modeling to find the threshold for
identifying known/unknown class samples. Experiments performed on multiple
image classification datasets show proposed method performs significantly
better than state of the art.Comment: CVPR2019 (Oral
Recommended from our members
Changes in forward light scatter parameters as a function of refractive error in young adults
Background/aims
Some aspects of visual performance worsen with increasing myopia. Whilst the underlying causes are not always clear, reduction in retinal image quality is often attributed to structural changes in the posterior myopic eye. Forward light scatter, originating principally from the cornea and lens, is known to produce veiling glare which subsequently reduces retinal image contrast. It is therefore of interest to investigate whether forward light scatter varies with refractive error.
Methods
Thirteen young-adult subjects (18–25 years), with mean spherical errors (MSE ± sd, D) RE, − 1.69 ± 2.02 (range 0.38 to − 4.75); LE, − 1.91 ± 1.94 (range 0.50 to − 4.63) underwent binocular assessment of forward light scatter using the AVOT light scatter test. Five glare annuli, with effective eccentricities ranging from 2 to 10°, were used to estimate parameters, k and n, which define the light scatter function of the eye. These were then used to calculate the area under the light scatter function (k′) and the total volume of light scatter (k″).
Results
Significant correlation was found between increasing myopia and k′ values (RE, p 0.05 for both eyes). Axial length was also not correlated with any of the light scatter parameters measured.
Conclusion
The preliminary data from this study provide evidence that some light scatter parameters may be correlated with refractive error. Further studies are needed to characterize how changes in the anterior media of the eye, and inclusion of a wider range of refractive errors, may affect forward light scatter
Flavour physics without flavour symmetries
We quantitatively analyze a quark-lepton flavour model derived from a
six-dimensional supersymmetric theory with gauge symmetry,
compactified on an orbifold with magnetic flux. Two bulk -plets
charged under the provide the three quark-lepton generations whereas two
uncharged -plets yield two Higgs doublets. At the orbifold fixed
points mass matrices are generated with rank one or two. Moreover, the zero
modes mix with heavy vectorlike split multiplets. The model possesses no
flavour symmetries. Nevertheless, there exist a number of relations between
Yukawa couplings, remnants of the underlying GUT symmetry and the wave function
profiles of the zero modes, which lead to a prediction of the light neutrino
mass scale, eV and heavy Majorana neutrino masses in
the range from GeV to GeV. The model successfully includes
thermal leptogenesis.Comment: Minor additions; Published versio
Yukawa coupling unification in SO(10) with positive \mu\ and a heavier gluino
The t-b-tau unification with positive Higgs mass parameter \mu\ in the
minimal supersymmetric standard model prefers "just so" Higgs splitting and a
light gluino < 500 GeV which appears to be ruled out by the recent LHC
searches. We reanalyze constraints on soft supersymmetry breaking parameters in
this scenario allowing independent splittings among squarks and Higgs doublets
at the grand unification scale and show that it is possible to obtain t-b-tau
unification and satisfy experimental constraints on gluino mass without raising
supersymmetry breaking scale to very high value ~ 20 TeV. We discuss the origin
of independent squark and Higgs splittings in realistic SO(10) models. Just so
Higgs splitting can be induced without significantly affecting the t-b-tau
unification in SO(10) models containing Higgs fields transforming as
10+\bar{126}+126+210. This splitting arises in the presence of non-universal
boundary conditions from mixing between 10 and other Higgs fields. Similarly,
if additional matter fields are introduced then their mixing with the matter
multiplet 16 is shown to generate the squark splitting required to raise the
gluino mass within the t-b-tau unified models with positive \mu.Comment: 19 pages, 6 figure
- …
