6,925 research outputs found
On the Anti-Wishart distribution
We provide the probability distribution function of matrix elements each of
which is the inner product of two vectors.
The vectors we are considering here are independently distributed but not
necessarily Gaussian variables.
When the number of components M of each vector is greater than the number of
vectors N, one has a symmetric matrix.
When and the components of each vector are independent Gaussian
variables, the distribution function of the matrix elements was
obtained by Wishart in 1928.
When N > M, what we called the ``Anti-Wishart'' case, the matrix elements are
no longer completely independent because the true degrees of freedom becomes
smaller than the number of matrix elements. Due to this singular nature,
analytical derivation of the probability distribution function is much more
involved than the corresponding Wishart case. For a class of general random
vectors, we obtain the analytical distribution function in a closed form, which
is a product of various factors and delta function constraints, composed of
various determinants. The distribution function of the matrix element for the
case with the same class of random vectors is also obtained as a
by-product. Our result is closely related to and should be valuable for the
study of random magnet problem and information redundancy problem.Comment: to appear in Physica
Decoding Information from noisy, redundant, and intentionally-distorted sources
Advances in information technology reduce barriers to information
propagation, but at the same time they also induce the information overload
problem. For the making of various decisions, mere digestion of the relevant
information has become a daunting task due to the massive amount of information
available. This information, such as that generated by evaluation systems
developed by various web sites, is in general useful but may be noisy and may
also contain biased entries. In this study, we establish a framework to
systematically tackle the challenging problem of information decoding in the
presence of massive and redundant data. When applied to a voting system, our
method simultaneously ranks the raters and the ratees using only the evaluation
data, consisting of an array of scores each of which represents the rating of a
ratee by a rater. Not only is our appraoch effective in decoding information,
it is also shown to be robust against various hypothetical types of noise as
well as intentional abuses.Comment: 19 pages, 5 figures, accepted for publication in Physica
Qubit Mapping Toward Quantum Advantage
Qubit Mapping is a pivotal stage in quantum compilation flow. Its goal is to
convert logical circuits into physical circuits so that a quantum algorithm can
be executed on real-world non-fully connected quantum devices. Qubit Mapping
techniques nowadays still lack the key to quantum advantage, scalability.
Several studies have proved that at least thousands of logical qubits are
required to achieve quantum computational advantage. However, to our best
knowledge, there is no previous research with the ability to solve the qubit
mapping problem with the necessary number of qubits for quantum advantage in a
reasonable time. In this work, we provide the first qubit mapping framework
with the scalability to achieve quantum advantage while accomplishing a fairly
good performance. The framework also boasts its flexibility for quantum
circuits of different characteristics. Experimental results show that the
proposed mapping method outperforms the state-of-the-art methods on quantum
circuit benchmarks by improving over 5% of the cost complexity in one-tenth of
the program running time. Moreover, we demonstrate the scalability of our
method by accomplishing mapping of an 11,969-qubit Quantum Fourier Transform
within five hours
Heat Conduction Process on Community Networks as a Recommendation Model
Using heat conduction mechanism on a social network we develop a systematic
method to predict missing values as recommendations. This method can treat very
large matrices that are typical of internet communities. In particular, with an
innovative, exact formulation that accommodates arbitrary boundary condition,
our method is easy to use in real applications. The performance is assessed by
comparing with traditional recommendation methods using real data.Comment: 4 pages, 2 figure
The role of thrombomodulin lectin-like domain in inflammation
Thrombomodulin (TM) is a cell surface glycoprotein which is widely expressed in a variety of cell types. It is a cofactor for thrombin binding that mediates protein C activation and inhibits thrombin activity. In addition to its anticoagulant activity, recent evidence has revealed that TM, especially its lectin-like domain, has potent anti-inflammatory function through a variety of molecular mechanisms. The lectin-like domain of TM plays an important role in suppressing inflammation independent of the TM anticoagulant activity. This article makes an extensive review of the role of TM in inflammation. The molecular targets of TM lectin-like domain have also been elucidated. Recombinant TM protein, especially the TM lectin-like domain may play a promising role in the management of sepsis, glomerulonephritis and arthritis. These data demonstrated the potential therapeutic role of TM in the treatment of inflammatory diseases
Emergence of topological phases from the extension of two-dimensional lattice with nonsymmorphic symmetries
Young and Kane have given a great insight for 2D Dirac semimetals with
nontrivial topology in the presence of nonsymmorphic crystalline symmetry.
Based on one of 2D nonsymmorphic square lattice structures they proposed, we
further construct a set of 3D minimal tight-binding models via vertically
stacking the 2D nonsymmorphic lattice. Specifically, our model provides a
platform to generate three topologically semimetallic phases such as Dirac
nodal line semimetals, Weyl nodal line semimetals and Weyl semimetals. The
off-centered mirror symmetry sufficiently protects nodal lines emerging within
mirror-invariant plane with a nontrivial mirror invariant ,
whereas twofold screw rotational symmetry protects nontrivial Weyl nodal points
with topological charge . Interestingly, Weyl nodal loops are generated
without mirror symmetry protection, where nontrivial "drumhead" surface states
emerge within loops. In the presence of both time-reversal and inversion
symmetries, the emergence of weak topological insulator phases is discussed as
well.Comment: 8 pages, 6 figures and 1 tabl
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