2,264 research outputs found
Exponents Associated with -Systems and their Relationship with -Series
Let be a finite type Dynkin diagram, and be a positive integer
greater than or equal to two. The -system of type with level is
a system of algebraic relations, whose solutions have been proved to have
periodicity. For any pair , we define an integer sequence called
exponents using formulation of the -system by cluster algebras. We give a
conjectural formula expressing the exponents by the root system of type ,
and prove this conjecture for and cases. We point out
that a specialization of this conjecture gives a relationship between the
exponents and the asymptotic dimension of an integrable highest weight module
of an affine Lie algebra. We also give a point of view from -series
identities for this relationship
A Giant Green Pea Identified in the Spectroscopy of Spatially Extended [OIII] Sources
We present the results of the deep Subaru/FOCAS and Keck/MOSFIRE spectroscopy
for four spatially extended [O III]4959,5007 sources, dubbed [O
III] blobs, at that are originally pinpointed by large-area Subaru
imaging surveys. The line diagnostics of the rest-frame optical lines suggests
that only one [O III] blob, OIIIB-3, presents an AGN signature, indicating that
hot gas of the rest of the [O III] blobs is heated by star formation. One of
such star-forming [O III] blobs, OIIIB-4, at has an [O III]
equivalent width of \r{A} and an [O III] to [O
II]3726,3729 ratio of [O III]/[O II]= that are as
high as those of typical green peas (Cardamone et al. 2009). The spatially
resolved spectrum of OIIIB-4 shows [O III]/[O II]= over kpc in the
entire large [O III] extended regions of OIIIB-4, unlike the known green peas
whose strong [O III] emission region is compact. Moreover, OIIIB-4 presents no
high ionization emission lines, unlike green beans that have extended [O III]
emission with a type-2 AGN. OIIIB-4 is thus a giant green pea, which is a low
stellar mass ( ) galaxy with a very high specific star
formation rate (sSFR = ), a high ionization
parameter (), and a low
metallicity similar to those of green peas. Neither an AGN-light echo nor a
fast radiative shock likely takes place due to the line diagnostics for
spatially-resolved components of OIIIB-4 and no detections of He
II4686 or [Ne V]3346,3426 lines that are
fast-radiative shock signatures. There is a possibility that the
spatially-extended [O III] emission of OIIIB-4 is originated from outflowing
gas produced by the intense star formation in a density-bounded ionization
state.Comment: 17 pages, 12 figures, 4 tables, Accepted for publication in Ap
Functional Dynamics by Intention Recognition in Iterated Games
Intention recognition is an important characteristic of intelligent agents.
In their interactions with others, they try to read others' intentions and make
an image of others to choose their actions accordingly. While the way in which
players choose their actions depending on such intentions has been investigated
in game theory, how dynamic changes in intentions by mutually reading others'
intentions are incorporated into game theory has not been explored. We present
a novel formulation of game theory in which players read others' intentions and
change their own through an iterated game. Here, intention is given as a
function of the other's action and the own action to be taken accordingly as
the dependent variable, while the mutual recognition of intention is
represented as the functional dynamics. It is shown that a player suffers no
disadvantage when he/she recognizes the other's intention, whereas the
functional dynamics reach equilibria in which both players' intentions are
optimized. These cover a classical Nash and Stackelberg equilibria but we
extend them in this study: Novel equilibria exist depending on the degree of
mutual recognition. Moreover, the degree to which each player recognizes the
other can also differ. This formulation is applied to resource competition,
duopoly, and prisoner's dilemma games. For example, in the resource competition
game with player-dependent capacity on gaining the resource, the superior
player's recognition leads to the exploitation of the other, while the inferior
player's recognition leads to cooperation through which both players' payoffs
increase.Comment: 20 pages, 6 figures, and supplementary materia
Schwartz type model selection for ergodic stochastic differential equation models
We study the construction of the theoretical foundation of model comparison
for ergodic stochastic differential equation (SDE) models and an extension of
the applicable scope of the conventional Bayesian information criterion.
Different from previous studies, we suppose that the candidate models are
possibly misspecified models, and we consider both Wiener and a pure-jump
L\'{e}vy noise driven SDE. Based on the asymptotic behavior of the marginal
quasi-log likelihood, the Schwarz type statistics and stepwise model selection
procedure are proposed. We also prove the model selection consistency of the
proposed statistics with respect to an optimal model. We conduct some numerical
experiments and they support our theoretical findings
Scene Segmentation-Based Luminance Adjustment for Multi-Exposure Image Fusion
We propose a novel method for adjusting luminance for multi-exposure image
fusion. For the adjustment, two novel scene segmentation approaches based on
luminance distribution are also proposed. Multi-exposure image fusion is a
method for producing images that are expected to be more informative and
perceptually appealing than any of the input ones, by directly fusing photos
taken with different exposures. However, existing fusion methods often produce
unclear fused images when input images do not have a sufficient number of
different exposure levels. In this paper, we point out that adjusting the
luminance of input images makes it possible to improve the quality of the final
fused images. This insight is the basis of the proposed method. The proposed
method enables us to produce high-quality images, even when undesirable inputs
are given. Visual comparison results show that the proposed method can produce
images that clearly represent a whole scene. In addition, multi-exposure image
fusion with the proposed method outperforms state-of-the-art fusion methods in
terms of MEF-SSIM, discrete entropy, tone mapped image quality index, and
statistical naturalness.Comment: will be published in IEEE Transactions on Image Processin
Two-step estimation of ergodic L\'evy driven SDE
We consider high frequency samples from ergodic L\'evy driven stochastic
differential equation (SDE) with drift coefficient and scale
coefficient involving unknown parameters and .
We suppose that the L\'evy measure , has all order moments but is not
fully specified. We will prove the joint asymptotic normality of some
estimators of , and a class of functional parameter
, which are constructed in a two-step manner: first,
we use the Gaussian quasi-likelihood for estimation of , and
then, for estimating we makes use of the method of
moments based on the Euler-type residual with the the previously obtained
quasi-likelihood estimator
Convolutional Neural Networks Considering Local and Global features for Image Enhancement
In this paper, we propose a novel convolutional neural network (CNN)
architecture considering both local and global features for image enhancement.
Most conventional image enhancement methods, including Retinex-based methods,
cannot restore lost pixel values caused by clipping and quantizing. CNN-based
methods have recently been proposed to solve the problem, but they still have a
limited performance due to network architectures not handling global features.
To handle both local and global features, the proposed architecture consists of
three networks: a local encoder, a global encoder, and a decoder. In addition,
high dynamic range (HDR) images are used for generating training data for our
networks. The use of HDR images makes it possible to train CNNs with
better-quality images than images directly captured with cameras. Experimental
results show that the proposed method can produce higher-quality images than
conventional image enhancement methods including CNN-based methods, in terms of
various objective quality metrics: TMQI, entropy, NIQE, and BRISQUE.Comment: To appear in Proc. ICIP2019. arXiv admin note: text overlap with
arXiv:1901.0568
Emergence of Exploitation as Symmetry Breaking in Iterated Prisoner's Dilemma
In society, mutual cooperation, defection, and asymmetric exploitative
relationships are common. Whereas cooperation and defection are studied
extensively in the literature on game theory, asymmetric exploitative
relationships between players are little explored. In a recent study, Press and
Dyson demonstrate that if only one player can learn about the other, asymmetric
exploitation is achieved in the prisoner's dilemma game. In contrast, however,
it is unknown whether such one-way exploitation is stably established when both
players learn about each other symmetrically and try to optimize their payoffs.
Here, we first formulate a dynamical system that describes the change in a
player's probabilistic strategy with reinforcement learning to obtain greater
payoffs, based on the recognition of the other player. By applying this
formulation to the standard prisoner's dilemma game, we numerically and
analytically demonstrate that an exploitative relationship can be achieved
despite symmetric strategy dynamics and symmetric rule of games. This
exploitative relationship is stable, even though the exploited player, who
receives a lower payoff than the exploiting player, has optimized the own
strategy. Whether the final equilibrium state is mutual cooperation, defection,
or exploitation, crucially depends on the initial conditions: Punishment
against a defector oscillates between the players, and thus a complicated basin
structure to the final equilibrium appears. In other words, slight differences
in the initial state may lead to drastic changes in the final state.
Considering the generality of the result, this study provides a new perspective
on the origin of exploitation in society.Comment: 19 pages, 7 figures, + supplement(8 pages, 2 figures
Design and Analysis on a Cryogenic Current Amplifier with a Superconducting Microwave Resonator
We propose a new type of cryogenic current amplifiers, in which low-frequency
power spectrum of current can be measured through a measurement of microwave
response of a superconducting resonant circuit shunted by a series array of
Josephson junctions. From numerical analysis on the equivalent circuit, the
numerical value of the input-referred current noise of the proposed amplifier
is found to be two orders of magnitude lower than the noise floor measured with
the conventional cryogenic current amplifiers based on high-electron-mobility
transistors or superconducting quantum interference devices. Our proposal can
open new avenues for investigating low-temperature solid-state devices that
require lower noise and wider bandwidth power spectrum measurements of current.Comment: 4 pages, 3 figure
Automatic Exposure Compensation for Multi-Exposure Image Fusion
This paper proposes a novel luminance adjustment method based on automatic
exposure compensation for multi-exposure image fusion. Multi-exposure image
fusion is a method to produce images without saturation regions, by using
photos with different exposures. In conventional works, it has been pointed out
that the quality of those multi-exposure images can be improved by adjusting
the luminance of them. However, how to determine the degree of adjustment has
never been discussed. This paper therefore proposes a way to automatically
determines the degree on the basis of the luminance distribution of input
multi-exposure images. Moreover, new weights, called "simple weights", for
image fusion are also considered for the proposed luminance adjustment method.
Experimental results show that the multi-exposure images adjusted by the
proposed method have better quality than the input multi-exposure ones in terms
of the well-exposedness. It is also confirmed that the proposed simple weights
provide the highest score of statistical naturalness and discrete entropy in
all fusion methods.Comment: To appear in Proc. ICIP2018 October 07-10, 2018, Athens, Greec
- …