8,603 research outputs found
Detection of Review Abuse via Semi-Supervised Binary Multi-Target Tensor Decomposition
Product reviews and ratings on e-commerce websites provide customers with
detailed insights about various aspects of the product such as quality,
usefulness, etc. Since they influence customers' buying decisions, product
reviews have become a fertile ground for abuse by sellers (colluding with
reviewers) to promote their own products or to tarnish the reputation of
competitor's products. In this paper, our focus is on detecting such abusive
entities (both sellers and reviewers) by applying tensor decomposition on the
product reviews data. While tensor decomposition is mostly unsupervised, we
formulate our problem as a semi-supervised binary multi-target tensor
decomposition, to take advantage of currently known abusive entities. We
empirically show that our multi-target semi-supervised model achieves higher
precision and recall in detecting abusive entities as compared to unsupervised
techniques. Finally, we show that our proposed stochastic partial natural
gradient inference for our model empirically achieves faster convergence than
stochastic gradient and Online-EM with sufficient statistics.Comment: Accepted to the 25th ACM SIGKDD Conference on Knowledge Discovery and
Data Mining, 2019. Contains supplementary material. arXiv admin note: text
overlap with arXiv:1804.0383
Analysis of the decay
In this paper we study the angular distribution of the rare B decay , which is expected to be observed soon. We use the
standard effective Hamiltonian approach, and use the form factors that have
already been estimated for the corresponding radiative decay . The additional form factors that come into play for the dileptonic
channel are estimated using the large energy effective theory (LEET), which
enables one to relate the additional form factors to the form factors for the
radiative mode. Our results provide, just like in the case of the
resonance, an opportunity for a straightforward comparison of the basic theory
with experimental results which may be expected in the near future for this
channel.Comment: 14 pages, 5 figures; as accepted for Phys. Rev.
Bound on Hardy's non-locality from the principle of Information Causality
Recently,the principle of nonviolation of information causality [Nature
461,1101 (2009)], has been proposed as one of the foundational properties of
nature. We explore the Hardy's nonlocality theorem for two qubit systems, in
the context of generalised probability theory, restricted by the principle of
nonviolation of information causality. Applying, a sufficient condition for
information causality violation, we derive an upper bound on the maximum
success probability of Hardy's nonlocality argument. We find that the bound
achieved here is higher than that allowed by quantum mechanics,but still much
less than what the nosignaling condition permits. We also study the Cabello
type nonlocality argument (a generalization of Hardy's argument) in this
context.Comment: Abstract modified, changes made in the conclusion, throughout the
paper we clarified that the condition used by us is protocal based and is
only a sufficient condition for the violation of information causalit
Identification of Ajnala skeletal remains using multiple forensic anthropological methods and techniques: a bioarchaeological report.
Fragmented and badly damaged commingled human remains present a tough challenge for their identification pursuits in forensic anthropology. Thousands of unknown human remains along with items of contextual identity, reportedly belonging to 282 Indian sepoys killed in 1857, were exhumed non-scientifically from a disused ancient well at Ajnala (Amritsar, India). In this manuscript, the non-scientific excavation of unknown human remains from the abandoned well, their forensic anthropological strategies for identification purposes, challenges being faced and future possibilities of their biological profiling have been discussed. Multiple methods and techniques like anthropological examinations, odontological profiling, radiological analyses, stable isotope and mitochondrial DNA (mtDNA) analyses were applied to few bones and teeth collected from the Ajnala skeletal assemblage. Though majority of studied bones and teeth were found belonging to adult males, very few of them had morphological, osteological and molecular features questioning the authenticity and validity of the written records. Due to certain ambiguous findings or gaps observed between the anthropological analyses of the Ajnala skeletal remains and the reported versions about their affiliations; certain advanced radiological, chemical and molecular techniques were applied to estimate their probable age, sex and populational affinity. The obtained radiological, isotopic and molecular signatures of the remains were compared with the available databases to estimate their affinity with the individuals of geographic area to whom the remains reportedly belonged to. The maternally inherited mtDNA haplogroup assignments, and stable isotope analysis of carbon and oxygen suggested that the studied human remains belonged to the individuals from West Bengal, Bihar, Odisha, Awadh (presently in Uttar Pradesh) and parts of Meghalaya and Manipur as potential regions of their geographic identity and thus, attributing the victims to be non-local to the site. However, merely on the basis of forensic anthropological examinations of very few bones and teeth (collected out of a huge collection of thousands of bones and teeth); it would be just an unqualified and sweeping conclusion to claim their identity as adult or non-adult, male or female, local or non-local, victims of 1857 mass killings or to the victims of ceremonial sacrifices or criminal activities committed in the past. A sufficient number of bones and teeth along with items of personal identity needs to be examined with multiple scientific techniques to arrive at some valid conclusions about their biological identity
Dissociative Autoionization in (1+2)-photon Above Threshold Excitation of H2 Molecules
We have theoretically studied the effect of dissociative autoionization on
the photoelectron energy spectrum in (1+2)-photon above threshold
ionization(ATI) of H2 molecules. We have considered excitation from the ground
state X-singlet-Sigma-g+(v=0,j) to the doubly excited autoionizing states of
singlet-Sigma-u+ and singlet-Pi-u+ symmetry, via the intermediate resonant
B-singlet-Sigma-u+(v=5,j) states. We have shown that the photoelectron energy
spectrum is oscillatory in nature and shows three distinct peaks above the
photoelectron energy 0.7 eV. This feature has been observed in a recent
experiment by Rottke et al, J. Phys. B, Vol. 30, p-4049 (1997).Comment: 11 pages and 4 figure
Deformation behavior of undoped and In-doped GaAs in the temperature range 700–1100 °C
Compressive deformation of undoped and In‐doped GaAs single crystals has been carried out in [001] and [123] orientations in the temperature range 700–1100 °C. Indium additions, at levels of 1–2×10^(20) atoms cm^(−3), result in critical resolved shear stress (CRSS) values that are about twice as large as the undoped crystals in the temperature range of 700–1100 °C. The CRSS was weakly dependent on temperature in the temperature range investigated as expected for a model of athermal solid solution hardening. The CRSS value of 3.3 MPa for the In‐doped crystal is sufficient to eliminate profuse dislocation formation in a 75‐mm‐diam crystal on the basis of current theories for the magnitude of the thermal stress experienced during growth. The results also suggest that the process of dislocation climb is slowed appreciably by In doping
Variation of rayleigh wave group velocity dispersion and seismic heterogeneity of the Indian crust and uppermost mantle
We present group velocity dispersion results from a study of regional fundamental mode Rayleigh waves propagating across the Indian region. 1-D, path-averaged dispersion measurements have been made for 1001 source-receiver paths and these combined to produce tomographic images between 15 and 45 s period. Because of the dense station coverage in peninsular India, these images have substantially higher lateral resolution for this region than is currently available from global and regional group velocity studies. Testing of the group velocity model shows that the average resolution across the region is about 7.5° for the periods used in this study. The tomographic maps demonstrate that while the Indian shield is characterized by high crustal and uppermost-mantle group velocities, comparatively lower velocities exist beneath the Himalaya due to the thickened crust and beneath the Gangetic plains caused by the mollasse sediments and recent alluvium cover in the Himalayan foredeep. Northeastern India north of the Shillong Plateau also displays higher velocities, similar to the south Indian shield, indicative of colder crust beneath the region. The northern Bay of Bengal shows extremely low velocities due to the thick sediment blanket of the Bengal fan. Likewise, the Katawaz Basin in southern Pakistan shows lower velocities that resemble those seen in the Bay of Bengal. The geometry of the velocity contours south of the Katawaz Basin closely matches the prograding Indus fan in the Arabian Sea. Finally, the Tibetan Plateau has lower group velocities compared to the Indian shield at all periods as a result of the thick crust beneath southern Tibet
A complementary relation between classical bits and randomness in local part in simulating singlet state
Recently Leggett's proposal of non-local model generates new interest in
simulating the statistics of singlet state. Singlet state statistics can be
simulated by 1 bit of classical communication without using any further
nonlocal correlation. But, interestingly, singlet state statistics can also be
simulated with no classical cost if a non-local box is used. In the first case,
the output is completely unbiased whereas in second case outputs are completely
random. We suggest a new (possibly) signaling correlation resource which
successfully simulates singlet statistics and this result suggests a new
complementary relation between required classical bits and randomness in local
output when the classical communication is limited by 1 cbit. This result
reproduces the above two models of simulation as extreme cases. This also
explains why Leggett's non-local model and the model presented by Branciard
et.al. should fail to reproduce the statistics of a singlet.Comment: v3: Typos corrected, few changed notations, some extensions to
earlier write-u
Some entanglement features of three-atoms Tavis-Cummings model: Cooperative case
In this paper we consider a system of identical three two-level atoms
interacting at resonance with a single-mode of the quantized field in a
lossless cavity. The initial cavity field is prepared in the coherent state
while the atoms are taken initially to be either in the uppermost excited state
"" or The -state or the -state. For this
system we investigate different kinds of atomic inversion and entanglement,
which arise between the different parts of the system due to the interaction.
Also the relationship, between entanglement and some other nonclassical effects
in the statistical properties, such as collapses and revivals in the atomic
inversion where superharmonic effects appear, is discussed. The -functions
for different cases are discussed. Most remarkably it is found that the
-state is more robust against energy losses, showing almost
coherent trapping and Schr\"odinger-cat states can not be produced from such
state. Also the entanglement of -state is more robust than the
-state. Another interesting feature found is that the state which
has no pairwise entanglement initially will have a much improvement of such
pairwise entanglement through the evolution. Sudden death and sudden revival of
atoms-pairwise entanglement are produced with the -state.Comment: 14 pages, 7 figure
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