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Our paper entitled “Quantum Annealing for Dirichlet Process Mixture Models with Applications to Network Clustering" was published in Neurocomputing. This work was done in collaboration with Dr. Issei Sato (Univ. of Tokyo), Dr. Kenichi Kurihara (Google), Professor Seiji Miyashita (Univ. of Tokyo), and Prof. Hiroshi Nakagawa (Univ. of Tokyo). http://www.sciencedirect.com/science/article/pii/S0925231213005535 The preprint version is available: http://arxiv.org/abs/1305.4325 佐藤一誠さん（東京大学）、栗原賢一さん（Google）、宮下精二教授（東京大学）、中川裕志教授（東京大学）との共同研究論文 “Quantum Annealing for Dirichlet Process Mixture Models with Applications to Network Clustering" が Neurocomputing に掲載されました。 http://www.sciencedirect.com/science/article/pii/S0925231213005535 プレプリントバージョンは http://arxiv.org/abs/1305.4325 からご覧いただけます。

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Unconventional phase transitions in frustrated systems (March, 2014)

Presentation file using the workshop which was held at the University of Tokyo (March 26, 2014). The presentation was based on two papers:
- Physical Review B Vol. 87, 214401 (2013)
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.214401
(preprint: http://arxiv.org/abs/1209.2520)
(A brief explanation: http://www.slideshare.net/shu-t/prb-87214401slideshare)
- Physical Review E Vol. 88, 052138 (2013)
http://journals.aps.org/pre/abstract/10.1103/PhysRevE.88.052138
(preprint: http://arxiv.org/abs/1308.2467)
(A brief explanation: http://www.slideshare.net/shu-t/interlayerinteraction-dependence-of-latent-heat-in-the-heisenberg-model-on-a-stacked-triangular-lattice-with-competing-interactions)
2014年３月26日に東京大学で開催された「統計物理学の新しい潮流」での講演スライドです。この講演は、以下の２つの論文に関係するものです。
- Physical Review B Vol. 87, 214401 (2013)
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.214401
(preprint: http://arxiv.org/abs/1209.2520)
(A brief explanation: http://www.slideshare.net/shu-t/prb-87214401slideshare)
- Physical Review E Vol. 88, 052138 (2013)
http://journals.aps.org/pre/abstract/10.1103/PhysRevE.88.052138
(preprint: http://arxiv.org/abs/1308.2467)
(A brief explanation: http://www.slideshare.net/shu-t/interlayerinteraction-dependence-of-latent-heat-in-the-heisenberg-model-on-a-stacked-triangular-lattice-with-competing-interactions)

Entanglement Behavior of 2D Quantum Models

I gave an oral presentation at YITP Workshop on Quantum Information Physics (YQIP2014).
http://www2.yukawa.kyoto-u.ac.jp/~yitpqip2014.ws/index.php
This presentation is based on the following papers.
http://iopscience.iop.org/1751-8121/43/25/255303
http://prb.aps.org/abstract/PRB/v84/i24/e245128
http://pra.aps.org/abstract/PRA/v86/i3/e032326
https://www.jstage.jst.go.jp/article/iis/19/1/19_IIS190115/_article
Preprint version are available via
http://arxiv.org/abs/1003.2007
http://arxiv.org/abs/1107.3888
http://arxiv.org/abs/1207.6752
http://arxiv.org/abs/1307.1939
京都大学基礎物理学研究所で開催されたワークショップ、"YITP Workshop on Quantum Information Physics (YQIP2014)"で口頭講演を行いました。
http://www2.yukawa.kyoto-u.ac.jp/~yitpqip2014.ws/index.php
本発表は以下の論文に基づいています。
http://iopscience.iop.org/1751-8121/43/25/255303
http://prb.aps.org/abstract/PRB/v84/i24/e245128
http://pra.aps.org/abstract/PRA/v86/i3/e032326
https://www.jstage.jst.go.jp/article/iis/19/1/19_IIS190115/_article
プレプリントバージョンは、以下のサイトから閲覧できます。
http://arxiv.org/abs/1003.2007
http://arxiv.org/abs/1107.3888
http://arxiv.org/abs/1207.6752
http://arxiv.org/abs/1307.1939

Interlayer-Interaction Dependence of Latent Heat in the Heisenberg Model on a...

Our paper entitled “Interlayer-Interaction Dependence of Latent Heat in the Heisenberg Model on a Stacked Triangular Lattice with Competing Interactions" was published in Physical Review E. This work was done in collaboration with Dr. Ryo Tamura (NIMS).
http://pre.aps.org/abstract/PRE/v88/i5/e052138
NIMSの田村亮さんとの共同研究論文 “Interlayer-Interaction Dependence of Latent Heat in the Heisenberg Model on a Stacked Triangular Lattice with Competing Interactions" が Physical Review E に掲載されました。
http://pre.aps.org/abstract/PRE/v88/i5/e052138

Second-Order Phase Transition in Heisenberg Model on Triangular Lattice with ...

Our paper entitled “Second-Order Phase Transition in Heisenberg Model on Triangular Lattice with Competing Interactions" was published in Physical Review B. This work was done in collaboration with Dr. Ryo Tamura (NIMS) and Professor Naoki Kawashima (ISSP).
http://prb.aps.org/abstract/PRB/v87/i21/e214401
NIMSの田村亮さん、物性研の川島直輝教授との共同研究論文 “Second-Order Phase Transition in Heisenberg Model on Triangular Lattice with Competing Interactions" が Physical Review B に掲載されました。
http://prb.aps.org/abstract/PRB/v87/i21/e214401

Network-Growth Rule Dependence of Fractal Dimension of Percolation Cluster on...

Our paper entitled “Network-Growth Rule Dependence of Fractal Dimension of Percolation Cluster on Square Lattice" was published in Journal of the Physical Society of Japan. This work was done in collaboration with Dr. Ryo Tamura (NIMS).
http://journals.jps.jp/doi/abs/10.7566/JPSJ.82.053002
NIMSの田村亮さんとの共同研究論文 “Network-Growth Rule Dependence of Fractal Dimension of Percolation Cluster on Square Lattice" が Journal of the Physical Society of Japan に掲載されました。
http://journals.jps.jp/doi/abs/10.7566/JPSJ.82.053002

Phase-field modeling of crystal nucleation II: Comparison with simulations an...

This document summarizes phase-field modeling of crystal nucleation. It discusses:
1) Homogeneous nucleation models using the phase-field method and their comparison to molecular dynamics simulations and experiments for systems like nickel and Lennard-Jones argon.
2) Applications of the phase-field model to heterogeneous systems like ice-water nucleation.
3) The effects of different double-well and interpolation functions on nucleation behavior in phase-field models.

Theoretical and Applied Phase-Field: Glimpses of the activities in India

1. The document summarizes recent work on phase-field modeling from several research groups in India.
2. It describes applications of phase-field modeling to spinodal decomposition, grain growth, precipitate evolution, and multi-phase solidification.
3. It highlights a recent study by the author using phase-field modeling to predict the equilibrium shapes of coherent precipitates under the influence of elastic stresses. The model accounts for elastic anisotropy and different eigenstrain configurations.

Phase-field modeling of crystal nucleation I: Fundamentals and methods

This document summarizes phase-field modeling of homogeneous crystal nucleation using two main methods. The first method adds fluctuations (noise) to the phase-field equations of motion to mimic natural nucleation. The noise amplitude is determined by the fluctuation-dissipation theorem. This models nucleation without assuming a sharp interface or bulk properties. The second method places supercritical crystal seeds randomly in space and time to model nucleation. Quantitative results from both methods are difficult to obtain due to limitations of classical nucleation theory. The document outlines the phase-field model and equations used to simulate homogeneous nucleation and crystal growth in 2D with and without noise to demonstrate convergence with spatial and temporal discretization.

Unconventional phase transitions in frustrated systems (March, 2014)

Presentation file using the workshop which was held at the University of Tokyo (March 26, 2014). The presentation was based on two papers:
- Physical Review B Vol. 87, 214401 (2013)
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.214401
(preprint: http://arxiv.org/abs/1209.2520)
(A brief explanation: http://www.slideshare.net/shu-t/prb-87214401slideshare)
- Physical Review E Vol. 88, 052138 (2013)
http://journals.aps.org/pre/abstract/10.1103/PhysRevE.88.052138
(preprint: http://arxiv.org/abs/1308.2467)
(A brief explanation: http://www.slideshare.net/shu-t/interlayerinteraction-dependence-of-latent-heat-in-the-heisenberg-model-on-a-stacked-triangular-lattice-with-competing-interactions)
2014年３月26日に東京大学で開催された「統計物理学の新しい潮流」での講演スライドです。この講演は、以下の２つの論文に関係するものです。
- Physical Review B Vol. 87, 214401 (2013)
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.214401
(preprint: http://arxiv.org/abs/1209.2520)
(A brief explanation: http://www.slideshare.net/shu-t/prb-87214401slideshare)
- Physical Review E Vol. 88, 052138 (2013)
http://journals.aps.org/pre/abstract/10.1103/PhysRevE.88.052138
(preprint: http://arxiv.org/abs/1308.2467)
(A brief explanation: http://www.slideshare.net/shu-t/interlayerinteraction-dependence-of-latent-heat-in-the-heisenberg-model-on-a-stacked-triangular-lattice-with-competing-interactions)

Entanglement Behavior of 2D Quantum Models

I gave an oral presentation at YITP Workshop on Quantum Information Physics (YQIP2014).
http://www2.yukawa.kyoto-u.ac.jp/~yitpqip2014.ws/index.php
This presentation is based on the following papers.
http://iopscience.iop.org/1751-8121/43/25/255303
http://prb.aps.org/abstract/PRB/v84/i24/e245128
http://pra.aps.org/abstract/PRA/v86/i3/e032326
https://www.jstage.jst.go.jp/article/iis/19/1/19_IIS190115/_article
Preprint version are available via
http://arxiv.org/abs/1003.2007
http://arxiv.org/abs/1107.3888
http://arxiv.org/abs/1207.6752
http://arxiv.org/abs/1307.1939
京都大学基礎物理学研究所で開催されたワークショップ、"YITP Workshop on Quantum Information Physics (YQIP2014)"で口頭講演を行いました。
http://www2.yukawa.kyoto-u.ac.jp/~yitpqip2014.ws/index.php
本発表は以下の論文に基づいています。
http://iopscience.iop.org/1751-8121/43/25/255303
http://prb.aps.org/abstract/PRB/v84/i24/e245128
http://pra.aps.org/abstract/PRA/v86/i3/e032326
https://www.jstage.jst.go.jp/article/iis/19/1/19_IIS190115/_article
プレプリントバージョンは、以下のサイトから閲覧できます。
http://arxiv.org/abs/1003.2007
http://arxiv.org/abs/1107.3888
http://arxiv.org/abs/1207.6752
http://arxiv.org/abs/1307.1939

Interlayer-Interaction Dependence of Latent Heat in the Heisenberg Model on a...

Our paper entitled “Interlayer-Interaction Dependence of Latent Heat in the Heisenberg Model on a Stacked Triangular Lattice with Competing Interactions" was published in Physical Review E. This work was done in collaboration with Dr. Ryo Tamura (NIMS).
http://pre.aps.org/abstract/PRE/v88/i5/e052138
NIMSの田村亮さんとの共同研究論文 “Interlayer-Interaction Dependence of Latent Heat in the Heisenberg Model on a Stacked Triangular Lattice with Competing Interactions" が Physical Review E に掲載されました。
http://pre.aps.org/abstract/PRE/v88/i5/e052138

Second-Order Phase Transition in Heisenberg Model on Triangular Lattice with ...

Our paper entitled “Second-Order Phase Transition in Heisenberg Model on Triangular Lattice with Competing Interactions" was published in Physical Review B. This work was done in collaboration with Dr. Ryo Tamura (NIMS) and Professor Naoki Kawashima (ISSP).
http://prb.aps.org/abstract/PRB/v87/i21/e214401
NIMSの田村亮さん、物性研の川島直輝教授との共同研究論文 “Second-Order Phase Transition in Heisenberg Model on Triangular Lattice with Competing Interactions" が Physical Review B に掲載されました。
http://prb.aps.org/abstract/PRB/v87/i21/e214401

Network-Growth Rule Dependence of Fractal Dimension of Percolation Cluster on...

Our paper entitled “Network-Growth Rule Dependence of Fractal Dimension of Percolation Cluster on Square Lattice" was published in Journal of the Physical Society of Japan. This work was done in collaboration with Dr. Ryo Tamura (NIMS).
http://journals.jps.jp/doi/abs/10.7566/JPSJ.82.053002
NIMSの田村亮さんとの共同研究論文 “Network-Growth Rule Dependence of Fractal Dimension of Percolation Cluster on Square Lattice" が Journal of the Physical Society of Japan に掲載されました。
http://journals.jps.jp/doi/abs/10.7566/JPSJ.82.053002

Phase-field modeling of crystal nucleation II: Comparison with simulations an...

This document summarizes phase-field modeling of crystal nucleation. It discusses:
1) Homogeneous nucleation models using the phase-field method and their comparison to molecular dynamics simulations and experiments for systems like nickel and Lennard-Jones argon.
2) Applications of the phase-field model to heterogeneous systems like ice-water nucleation.
3) The effects of different double-well and interpolation functions on nucleation behavior in phase-field models.

Theoretical and Applied Phase-Field: Glimpses of the activities in India

1. The document summarizes recent work on phase-field modeling from several research groups in India.
2. It describes applications of phase-field modeling to spinodal decomposition, grain growth, precipitate evolution, and multi-phase solidification.
3. It highlights a recent study by the author using phase-field modeling to predict the equilibrium shapes of coherent precipitates under the influence of elastic stresses. The model accounts for elastic anisotropy and different eigenstrain configurations.

Phase-field modeling of crystal nucleation I: Fundamentals and methods

This document summarizes phase-field modeling of homogeneous crystal nucleation using two main methods. The first method adds fluctuations (noise) to the phase-field equations of motion to mimic natural nucleation. The noise amplitude is determined by the fluctuation-dissipation theorem. This models nucleation without assuming a sharp interface or bulk properties. The second method places supercritical crystal seeds randomly in space and time to model nucleation. Quantitative results from both methods are difficult to obtain due to limitations of classical nucleation theory. The document outlines the phase-field model and equations used to simulate homogeneous nucleation and crystal growth in 2D with and without noise to demonstrate convergence with spatial and temporal discretization.

Spectral properties of the Goldstino in supersymmetric Bose-Fermi mixtures

This document summarizes research on properties of the Goldstino in supersymmetric Bose-Fermi mixtures. In the free case with no interactions, the Goldstino spectrum consists of both a continuum and a pole. The pole represents the Nambu-Goldstone mode with dispersion relation ω=Δμ-thp^2. At zero temperature, the continuum arises from Landau damping processes. Both the pole and continuum satisfy sum rules and contribute to conserved quantities like total density. Finite temperature effects on the Goldstino spectrum are also studied in the non-interacting case. The goal is to understand Goldstino properties that could be observed experimentally in cold atom systems which provide a clean realization of supersymmetry.

Complex Dynamics and Statistics in Hamiltonian 1-D Lattices - Tassos Bountis

Complex Dynamics and Statistics in Hamiltonian 1-D Lattices - Tassos Bountis Lake Como School of Advanced Studies

This document provides an outline for a lecture on complex dynamics in Hamiltonian systems. Some key points:
1) Simple periodic orbits called nonlinear normal modes exist and can destabilize, leading to weak or strong chaos depending on their properties.
2) Dynamical indicators like Lyapunov exponents and the Generalized Alignment Index (GALI) can identify regions of order and chaos. The Lyapunov spectrum indicates when orbits explore the same chaotic region.
3) GALI rapidly detects chaos as deviation vectors become aligned, and identifies quasiperiodic motion by vectors remaining independent. It distinguishes weak and strong chaos based on exponential decay rates.NITheP UKZN Seminar: Prof. Alexander Gorokhov (Samara State University, Russi...

This document discusses the application of dynamical groups and coherent states in quantum optics and molecular spectroscopy. It provides an introduction to using Lie groups and algebras to describe quantum systems and defines coherent states. Specific applications discussed include using dynamical symmetries to calculate energy levels of systems like the harmonic oscillator and hydrogen atom. Coherent states are used to derive classical equations of motion and represent open quantum systems. Examples of coherent state dynamics are shown for two-level and three-level atoms interacting with laser fields.

Quantum chaos of generic systems - Marko Robnik

This document summarizes research on quantum chaos, including the principle of uniform semiclassical condensation of Wigner functions, spectral statistics in mixed systems, and dynamical localization of chaotic eigenstates. It discusses how in the semiclassical limit, Wigner functions condense uniformly on classical invariant components. For mixed systems, the spectrum can be seen as a superposition of regular and chaotic level sequences. Localization effects can be observed if the Heisenberg time is shorter than the classical diffusion time. The document presents an analytical formula called BRB that describes the transition between Poisson and random matrix statistics. An example is given of applying this to analyze the level spacing distribution for a billiard system.

Quantum chaos in clean many-body systems - Tomaž Prosen

This document discusses quantum chaos in clean many-body systems. It begins by outlining the topic and noting that quantum chaos fits into many-body physics and statistical mechanics. It then discusses how the quantum chaos conjecture relates semiclassical physics to many-body systems. Specifically, it discusses how quantum ergodicity, decay of correlations, and Loschmidt echo relate to the integrability-breaking phase transition in spin chains. It also briefly mentions how quantum chaos appears in non-equilibrium steady states of open many-body systems.

Neutral Electronic Excitations: a Many-body approach to the optical absorptio...

Neutral Electronic Excitations: a Many-body approach to the optical absorption spectra.
Introduction to Bethe-Salpeter equation and linear response theory.

Introduction to Quantum Monte Carlo

This document provides an introduction to quantum Monte Carlo methods. It discusses using Monte Carlo integration to evaluate multi-dimensional integrals that arise in quantum mechanical problems. Variational Monte Carlo is introduced as using a trial wavefunction to sample configuration space and estimate observables, like the energy. The Metropolis algorithm is described as a way to generate Markov chains that sample a given probability distribution. This allows using Monte Carlo methods to solve the electronic structure problem by approximating many-body wavefunctions and integrals over configuration space.

SV-InclusionSOcouplinginNaCs

The document discusses including spin-orbit coupling in the author's model of photoassociation and rovibrational relaxation in NaCs. It presents the theoretical description, including the Hamiltonian with additional terms for spin-orbit interaction. The system is described by a wavefunction in the Born-Oppenheimer approximation. Equations are derived for the probability amplitudes of relevant rovibrational states including spin-orbit coupling between the A1Σ+ and b3Π electronic states. The initial condition of the scattering system at ultracold temperature is specified.

Dr. Arpan Bhattacharyya (Indian Institute Of Science, Bangalore)

1. The document discusses entanglement entropy functionals for higher derivative gravity theories. It proposes new area functionals for computing entanglement entropy in higher derivative theories containing polynomials of curvature tensors.
2. These functionals are derived using the Lewkowycz-Maldacena interpretation of generalized entropy. However, attempting to derive the extremal surface equations from these functionals using bulk equations of motion leads to inconsistencies and ambiguities in some higher derivative theories like Gauss-Bonnet gravity.
3. The document suggests that the source of ambiguity lies in the limiting procedure used to extract the divergences near the conical singularity. Different limiting paths can lead to different extremal surface equations, indicating no unique prescription

Dynamic stiffness and eigenvalues of nonlocal nano beams

Dynamic stiffness and eigenvalues of nonlocal nano beams - new methods for dynamic analysis of nano-scale structures. This lecture gives a review and proposed new techniques.

Wits Node Seminar: Dr Sunandan Gangopadhyay (NITheP Stellenbosch) TITLE: Path...

Wits Node Seminar: Dr Sunandan Gangopadhyay (NITheP Stellenbosch)
TITLE: Path integral action of a particle in the noncommutative plane and the Aharonov-Bohm effect

Prof. Vishnu Jejjala (Witwatersrand) TITLE: "The Geometry of Generations"

This document summarizes Vishnu Jejjala's talk "The Geometry of Generations" given at the University of the witwatersrand on 23 September 2014. It discusses using the geometry of vacuum moduli spaces of supersymmetric gauge theories to understand phenomenological aspects of the Standard Model, such as the number of generations. It provides examples of calculating the vacuum moduli space for simple supersymmetric gauge theories and outlines a process for obtaining the moduli space from the F-term and D-term equations.

Stochastic Gravity in Conformally-flat Spacetimes

The National Institute for Theoretical Physics, and the Mandelstam Institute for Theoretical Physics, School of Physics, would like to invite to its coming talk in the theoretical physics seminar series, entitled:
"Stochastic Gravity in Conformally-flat Spacetimes"
to be presented by Prof. Hing-Tong Cho (Tamkang University, Taiwan)
Abstract: The theory of stochastic gravity takes into account the effects of quantum field fluctuations onto the classical spacetime. The essential physics can be understood from the analogous Brownian motion model. We shall next concentrate on the case with conformally-flat spacetimes. Our main concern is to derive the so-called noise kernels. We shall also describe our on-going program to investigate the Einstein-Langevin equation in these spacetimes.
Dates: Tuesday, 17th February 2015
Venue: The Frank Nabarro lecture theatre, P216
Time: 13.20 - 14.10 - TODAY

A02402001011

International Journal of Mathematics and Statistics Invention (IJMSI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJMSI publishes research articles and reviews within the whole field Mathematics and Statistics, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.

Bethe salpeter equation

The document discusses the Bethe-Salpeter equation (BSE) which accounts for electron-hole interactions beyond the independent particle approximation. It summarizes that the BSE is derived from the equation of motion for the response function and results in an effective two-particle Hamiltonian that describes electron-hole excitations when diagonalized. Solving the BSE for lithium fluoride improves agreement with experimental optical spectra by including excitonic effects neglected by the independent particle picture.

BSE and TDDFT at work

- Optical spectra can be efficiently calculated using Green's function theory and the Bethe-Salpeter equation (BSE) or time-dependent density functional theory (TDDFT) formulated in the electron-hole space.
- The Lanczos-Haydock approach can be used to solve the BSE and TDDFT equations without fully diagonalizing the large matrices, greatly improving computational efficiency.
- While TDDFT provides a lower-cost approximation, the BSE more fully accounts for electron-hole interactions and is less prone to breakdowns like those from the Tamm-Dancoff approximation.

Complexity of exact solutions of many body systems: nonequilibrium steady sta...

Complexity of exact solutions of many body systems: nonequilibrium steady sta...Lake Como School of Advanced Studies

1) The document discusses exact solutions of nonequilibrium steady states in many-body quantum systems using the matrix product ansatz.
2) It presents an exactly solvable model of a boundary driven XXZ spin chain, where the nonequilibrium steady state can be represented as a matrix product operator with a quadratic algebra.
3) Transport properties like the spin conductivity can be computed exactly using conservation laws that emerge from the integrability of the model.Chebyshev Polynomial Based Numerical Inverse Laplace Transform Solutions of L...

Linear Volterra Integral and Integro-Differential equations are extensively used in the various specialties of science and engineering.

Linear response theory

This document discusses linear response theory and how to calculate the dielectric constant from first principles. It introduces Maxwell's equations and the relationship between polarization, electric field, and dielectric constant. The key steps are: 1) Expressing response functions in a single-particle basis set; 2) Setting up the time-dependent Hamiltonian and density matrix equation of motion; 3) Solving the equation of motion to obtain the linear response function χ0 in terms of single-particle energies and occupations. Local field effects beyond the independent particle approximation are included within the random phase approximation. The dielectric function ε is then constructed from the linear response function χ0.

TwoLevelMedium

This document describes a method for simulating electromagnetic wave propagation in two-level dielectric media using time-domain transmission line modeling (TLM). The technique incorporates a semi-classical model of a two-level medium to simulate its quantum properties within the TLM method. The approach is validated by showing it corresponds to the classical Lorentz oscillator model for small signals and excitations. Results demonstrate absorption, amplification, self-induced transparency and lasing in the two-level medium.

Metodo Monte Carlo -Wang Landau

Wang-Landau Monte Carlo simulation is a method for calculating the density of states function which can then be used to calculate thermodynamic properties like the mean value of variables. It improves on traditional Monte Carlo methods which struggle at low temperatures due to complicated energy landscapes with many local minima separated by large barriers. The Wang-Landau algorithm calculates the density of states function directly rather than relying on sampling configurations, allowing it to overcome barriers and fully explore the configuration space even at low temperatures.

C024015024

This paper provides alternative optimal expressions for determining matrices of a class of double-delay autonomous linear differential systems. The paper extends previous work by resolving ambiguities in permutations and analyzing computational complexity and cardinalities of determining matrices. Key results include theorems and corollaries that provide expressions for determining matrices ( )kQ jh in terms of sums of permutation products involving system matrices A, A1, A2. The expressions are proven to be consistent with previous work and fill gaps in the prior literature.

Spectral properties of the Goldstino in supersymmetric Bose-Fermi mixtures

This document summarizes research on properties of the Goldstino in supersymmetric Bose-Fermi mixtures. In the free case with no interactions, the Goldstino spectrum consists of both a continuum and a pole. The pole represents the Nambu-Goldstone mode with dispersion relation ω=Δμ-thp^2. At zero temperature, the continuum arises from Landau damping processes. Both the pole and continuum satisfy sum rules and contribute to conserved quantities like total density. Finite temperature effects on the Goldstino spectrum are also studied in the non-interacting case. The goal is to understand Goldstino properties that could be observed experimentally in cold atom systems which provide a clean realization of supersymmetry.

Complex Dynamics and Statistics in Hamiltonian 1-D Lattices - Tassos Bountis

Complex Dynamics and Statistics in Hamiltonian 1-D Lattices - Tassos Bountis Lake Como School of Advanced Studies

This document provides an outline for a lecture on complex dynamics in Hamiltonian systems. Some key points:
1) Simple periodic orbits called nonlinear normal modes exist and can destabilize, leading to weak or strong chaos depending on their properties.
2) Dynamical indicators like Lyapunov exponents and the Generalized Alignment Index (GALI) can identify regions of order and chaos. The Lyapunov spectrum indicates when orbits explore the same chaotic region.
3) GALI rapidly detects chaos as deviation vectors become aligned, and identifies quasiperiodic motion by vectors remaining independent. It distinguishes weak and strong chaos based on exponential decay rates.NITheP UKZN Seminar: Prof. Alexander Gorokhov (Samara State University, Russi...

This document discusses the application of dynamical groups and coherent states in quantum optics and molecular spectroscopy. It provides an introduction to using Lie groups and algebras to describe quantum systems and defines coherent states. Specific applications discussed include using dynamical symmetries to calculate energy levels of systems like the harmonic oscillator and hydrogen atom. Coherent states are used to derive classical equations of motion and represent open quantum systems. Examples of coherent state dynamics are shown for two-level and three-level atoms interacting with laser fields.

Quantum chaos of generic systems - Marko Robnik

This document summarizes research on quantum chaos, including the principle of uniform semiclassical condensation of Wigner functions, spectral statistics in mixed systems, and dynamical localization of chaotic eigenstates. It discusses how in the semiclassical limit, Wigner functions condense uniformly on classical invariant components. For mixed systems, the spectrum can be seen as a superposition of regular and chaotic level sequences. Localization effects can be observed if the Heisenberg time is shorter than the classical diffusion time. The document presents an analytical formula called BRB that describes the transition between Poisson and random matrix statistics. An example is given of applying this to analyze the level spacing distribution for a billiard system.

Quantum chaos in clean many-body systems - Tomaž Prosen

This document discusses quantum chaos in clean many-body systems. It begins by outlining the topic and noting that quantum chaos fits into many-body physics and statistical mechanics. It then discusses how the quantum chaos conjecture relates semiclassical physics to many-body systems. Specifically, it discusses how quantum ergodicity, decay of correlations, and Loschmidt echo relate to the integrability-breaking phase transition in spin chains. It also briefly mentions how quantum chaos appears in non-equilibrium steady states of open many-body systems.

Neutral Electronic Excitations: a Many-body approach to the optical absorptio...

Neutral Electronic Excitations: a Many-body approach to the optical absorption spectra.
Introduction to Bethe-Salpeter equation and linear response theory.

Introduction to Quantum Monte Carlo

This document provides an introduction to quantum Monte Carlo methods. It discusses using Monte Carlo integration to evaluate multi-dimensional integrals that arise in quantum mechanical problems. Variational Monte Carlo is introduced as using a trial wavefunction to sample configuration space and estimate observables, like the energy. The Metropolis algorithm is described as a way to generate Markov chains that sample a given probability distribution. This allows using Monte Carlo methods to solve the electronic structure problem by approximating many-body wavefunctions and integrals over configuration space.

SV-InclusionSOcouplinginNaCs

The document discusses including spin-orbit coupling in the author's model of photoassociation and rovibrational relaxation in NaCs. It presents the theoretical description, including the Hamiltonian with additional terms for spin-orbit interaction. The system is described by a wavefunction in the Born-Oppenheimer approximation. Equations are derived for the probability amplitudes of relevant rovibrational states including spin-orbit coupling between the A1Σ+ and b3Π electronic states. The initial condition of the scattering system at ultracold temperature is specified.

Dr. Arpan Bhattacharyya (Indian Institute Of Science, Bangalore)

1. The document discusses entanglement entropy functionals for higher derivative gravity theories. It proposes new area functionals for computing entanglement entropy in higher derivative theories containing polynomials of curvature tensors.
2. These functionals are derived using the Lewkowycz-Maldacena interpretation of generalized entropy. However, attempting to derive the extremal surface equations from these functionals using bulk equations of motion leads to inconsistencies and ambiguities in some higher derivative theories like Gauss-Bonnet gravity.
3. The document suggests that the source of ambiguity lies in the limiting procedure used to extract the divergences near the conical singularity. Different limiting paths can lead to different extremal surface equations, indicating no unique prescription

Dynamic stiffness and eigenvalues of nonlocal nano beams

Dynamic stiffness and eigenvalues of nonlocal nano beams - new methods for dynamic analysis of nano-scale structures. This lecture gives a review and proposed new techniques.

Wits Node Seminar: Dr Sunandan Gangopadhyay (NITheP Stellenbosch) TITLE: Path...

Wits Node Seminar: Dr Sunandan Gangopadhyay (NITheP Stellenbosch)
TITLE: Path integral action of a particle in the noncommutative plane and the Aharonov-Bohm effect

Prof. Vishnu Jejjala (Witwatersrand) TITLE: "The Geometry of Generations"

This document summarizes Vishnu Jejjala's talk "The Geometry of Generations" given at the University of the witwatersrand on 23 September 2014. It discusses using the geometry of vacuum moduli spaces of supersymmetric gauge theories to understand phenomenological aspects of the Standard Model, such as the number of generations. It provides examples of calculating the vacuum moduli space for simple supersymmetric gauge theories and outlines a process for obtaining the moduli space from the F-term and D-term equations.

Stochastic Gravity in Conformally-flat Spacetimes

The National Institute for Theoretical Physics, and the Mandelstam Institute for Theoretical Physics, School of Physics, would like to invite to its coming talk in the theoretical physics seminar series, entitled:
"Stochastic Gravity in Conformally-flat Spacetimes"
to be presented by Prof. Hing-Tong Cho (Tamkang University, Taiwan)
Abstract: The theory of stochastic gravity takes into account the effects of quantum field fluctuations onto the classical spacetime. The essential physics can be understood from the analogous Brownian motion model. We shall next concentrate on the case with conformally-flat spacetimes. Our main concern is to derive the so-called noise kernels. We shall also describe our on-going program to investigate the Einstein-Langevin equation in these spacetimes.
Dates: Tuesday, 17th February 2015
Venue: The Frank Nabarro lecture theatre, P216
Time: 13.20 - 14.10 - TODAY

A02402001011

International Journal of Mathematics and Statistics Invention (IJMSI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJMSI publishes research articles and reviews within the whole field Mathematics and Statistics, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.

Bethe salpeter equation

The document discusses the Bethe-Salpeter equation (BSE) which accounts for electron-hole interactions beyond the independent particle approximation. It summarizes that the BSE is derived from the equation of motion for the response function and results in an effective two-particle Hamiltonian that describes electron-hole excitations when diagonalized. Solving the BSE for lithium fluoride improves agreement with experimental optical spectra by including excitonic effects neglected by the independent particle picture.

BSE and TDDFT at work

- Optical spectra can be efficiently calculated using Green's function theory and the Bethe-Salpeter equation (BSE) or time-dependent density functional theory (TDDFT) formulated in the electron-hole space.
- The Lanczos-Haydock approach can be used to solve the BSE and TDDFT equations without fully diagonalizing the large matrices, greatly improving computational efficiency.
- While TDDFT provides a lower-cost approximation, the BSE more fully accounts for electron-hole interactions and is less prone to breakdowns like those from the Tamm-Dancoff approximation.

Complexity of exact solutions of many body systems: nonequilibrium steady sta...

Complexity of exact solutions of many body systems: nonequilibrium steady sta...Lake Como School of Advanced Studies

1) The document discusses exact solutions of nonequilibrium steady states in many-body quantum systems using the matrix product ansatz.
2) It presents an exactly solvable model of a boundary driven XXZ spin chain, where the nonequilibrium steady state can be represented as a matrix product operator with a quadratic algebra.
3) Transport properties like the spin conductivity can be computed exactly using conservation laws that emerge from the integrability of the model.Chebyshev Polynomial Based Numerical Inverse Laplace Transform Solutions of L...

Linear Volterra Integral and Integro-Differential equations are extensively used in the various specialties of science and engineering.

Linear response theory

This document discusses linear response theory and how to calculate the dielectric constant from first principles. It introduces Maxwell's equations and the relationship between polarization, electric field, and dielectric constant. The key steps are: 1) Expressing response functions in a single-particle basis set; 2) Setting up the time-dependent Hamiltonian and density matrix equation of motion; 3) Solving the equation of motion to obtain the linear response function χ0 in terms of single-particle energies and occupations. Local field effects beyond the independent particle approximation are included within the random phase approximation. The dielectric function ε is then constructed from the linear response function χ0.

TwoLevelMedium

This document describes a method for simulating electromagnetic wave propagation in two-level dielectric media using time-domain transmission line modeling (TLM). The technique incorporates a semi-classical model of a two-level medium to simulate its quantum properties within the TLM method. The approach is validated by showing it corresponds to the classical Lorentz oscillator model for small signals and excitations. Results demonstrate absorption, amplification, self-induced transparency and lasing in the two-level medium.

Spectral properties of the Goldstino in supersymmetric Bose-Fermi mixtures

Spectral properties of the Goldstino in supersymmetric Bose-Fermi mixtures

Complex Dynamics and Statistics in Hamiltonian 1-D Lattices - Tassos Bountis

Complex Dynamics and Statistics in Hamiltonian 1-D Lattices - Tassos Bountis

NITheP UKZN Seminar: Prof. Alexander Gorokhov (Samara State University, Russi...

NITheP UKZN Seminar: Prof. Alexander Gorokhov (Samara State University, Russi...

Quantum chaos of generic systems - Marko Robnik

Quantum chaos of generic systems - Marko Robnik

Quantum chaos in clean many-body systems - Tomaž Prosen

Quantum chaos in clean many-body systems - Tomaž Prosen

Neutral Electronic Excitations: a Many-body approach to the optical absorptio...

Neutral Electronic Excitations: a Many-body approach to the optical absorptio...

Introduction to Quantum Monte Carlo

Introduction to Quantum Monte Carlo

SV-InclusionSOcouplinginNaCs

SV-InclusionSOcouplinginNaCs

Dr. Arpan Bhattacharyya (Indian Institute Of Science, Bangalore)

Dr. Arpan Bhattacharyya (Indian Institute Of Science, Bangalore)

Dynamic stiffness and eigenvalues of nonlocal nano beams

Dynamic stiffness and eigenvalues of nonlocal nano beams

Wits Node Seminar: Dr Sunandan Gangopadhyay (NITheP Stellenbosch) TITLE: Path...

Wits Node Seminar: Dr Sunandan Gangopadhyay (NITheP Stellenbosch) TITLE: Path...

Prof. Vishnu Jejjala (Witwatersrand) TITLE: "The Geometry of Generations"

Prof. Vishnu Jejjala (Witwatersrand) TITLE: "The Geometry of Generations"

Stochastic Gravity in Conformally-flat Spacetimes

Stochastic Gravity in Conformally-flat Spacetimes

A02402001011

A02402001011

Bethe salpeter equation

Bethe salpeter equation

BSE and TDDFT at work

BSE and TDDFT at work

Complexity of exact solutions of many body systems: nonequilibrium steady sta...

Complexity of exact solutions of many body systems: nonequilibrium steady sta...

Chebyshev Polynomial Based Numerical Inverse Laplace Transform Solutions of L...

Chebyshev Polynomial Based Numerical Inverse Laplace Transform Solutions of L...

Linear response theory

Linear response theory

TwoLevelMedium

TwoLevelMedium

Metodo Monte Carlo -Wang Landau

Wang-Landau Monte Carlo simulation is a method for calculating the density of states function which can then be used to calculate thermodynamic properties like the mean value of variables. It improves on traditional Monte Carlo methods which struggle at low temperatures due to complicated energy landscapes with many local minima separated by large barriers. The Wang-Landau algorithm calculates the density of states function directly rather than relying on sampling configurations, allowing it to overcome barriers and fully explore the configuration space even at low temperatures.

C024015024

This paper provides alternative optimal expressions for determining matrices of a class of double-delay autonomous linear differential systems. The paper extends previous work by resolving ambiguities in permutations and analyzing computational complexity and cardinalities of determining matrices. Key results include theorems and corollaries that provide expressions for determining matrices ( )kQ jh in terms of sums of permutation products involving system matrices A, A1, A2. The expressions are proven to be consistent with previous work and fill gaps in the prior literature.

Estimating structured vector autoregressive models

- The document discusses estimating structured vector autoregressive (VAR) models from time series data.
- A VAR model of order d is defined as xt = A1xt-1 + ... + Adxt-d + εt, where xt is a p-dimensional time series, Ak are parameter matrices, and εt is noise.
- The document proposes regularizing the VAR model estimation problem to promote structured sparsity in the parameter matrices Ak. This involves transforming the model into a linear regression form and applying group lasso or fused lasso regularization.

A New Enhanced Method of Non Parametric power spectrum Estimation.

The spectral analysis of non uniform sampled data sequences using Fourier Periodogram method is the classical approach. In view of data fitting and computational standpoints why the Least squares periodogram(LSP) method is preferable than the “classical” Fourier periodogram and as well as to the frequently-used form of LSP due to Lomb and Scargle is explained. Then a new method of spectral analysis of nonuniform data sequences can be interpreted as an iteratively weighted LSP that makes use of a data-dependent weighting matrix built from the most recent spectral estimate. It is iterative and it makes use of an adaptive (i.e., data-dependent) weighting, we refer to it as the iterative adaptive approach (IAA).LSP and IAA are nonparametric methods that can be used for the spectral analysis of general data sequences with both continuous and discrete spectra. However, they are most suitable for data sequences with discrete spectra (i.e., sinusoidal data), which is the case we emphasize in this paper. Of the existing methods for nonuniform sinusoidal data, Welch, MUSIC and ESPRIT methods appear to be the closest in spirit to the IAA proposed here. Indeed, all these methods make use of the estimated covariance matrix that is computed in the first iteration of IAA from LSP. MUSIC and ESPRIT, on the other hand, are parametric methods that require a guess of the number of sinusoidal components present in the data, otherwise they cannot be used; furthermore.

On observer design methods for a

The generalized design principle of TS fuzzy observers for one class of continuous-time
nonlinear MIMO systems is presented in this paper. The problem addressed can be indicated as
a descriptor system approach to TS fuzzy observers design, implying the asymptotic convergence of the state observer error. A new structure of linear matrix inequalities is outlined to possess the observer asymptotic dynamic properties closest to the optimal.

A05920109

The document presents a theorem on random fixed points in metric spaces. It begins with introductions to fixed point theory, random fixed point theory, and relevant definitions. The main result is Theorem 3.1, which proves that if a self-mapping E on a complete metric space X satisfies certain contraction conditions involving parameters between 0 and 1, then E has a unique fixed point. The proof constructs a Cauchy sequence that converges to the unique fixed point. The document contributes to the study of random equations and random fixed point theory, which has applications in nonlinear analysis, probability theory, and other fields.

Efficient Simulations for Contamination of Groundwater Aquifers under Uncerta...

Efficient Simulations for Contamination of Groundwater Aquifers under Uncerta...Alexander Litvinenko

1. Solved time-dependent density driven flow problem with uncertain porosity and permeability in 2D and 3D
2. Computed propagation of uncertainties in porosity into the mass fraction.
3. Computed the mean, variance, exceedance probabilities, quantiles, risks.
4. Such QoIs as the number of fingers, their size, shape, propagation time can be unstable
5. For moderate perturbations, our gPCE surrogate results are similar to qMC results.
6. Used highly scalable solver on up to 800 computing nodes,
Conference ppt

This document presents a novel method called the Eigenfunction Expansion Method (EFEM) for analytically solving transient heat conduction problems with phase change in cylindrical coordinates. The method involves formulating the governing equations and associated boundary conditions, introducing coefficients, solving the eigenvalue problems, and representing the solution as a series expansion of the eigenfunctions. Dimensionless parameters are introduced to simplify the problem. The EFEM is then applied to solve a one-dimensional phase change problem. Results show that increasing the number of terms in the series expansion decreases the truncation error and that the Stefan number affects the melting fraction evolution over time.

Finite frequency H∞ control for wind turbine systems in T-S form

Finite frequency H∞ control for wind turbine systems in T-S formInternational Journal of Power Electronics and Drive Systems

In this work, we study H∞ control wind turbine fuzzy model for finite frequency(FF) interval. Less conservative results are obtained by using Finsler’s lemma technique, generalized Kalman Yakubovich Popov (gKYP), linear matrix inequality (LMI) approach and added several separate parameters, these conditions are given in terms of LMI which can be efficiently solved numerically for the problem that such fuzzy systems are admissible with H∞ disturbance attenuation level. The FF H∞ performance approach allows the state feedback command in a specific interval, the simulation example is given to validate our results.Response Surface in Tensor Train format for Uncertainty Quantification

We apply low-rank Tensor Train format to solve PDEs with uncertain coefficients. First, we approximate uncertain permeability coefficient in TT format, then the operator and then apply iterations to solve stochastic Galerkin system.

Stability of Iteration for Some General Operators in b-Metric

This document discusses the stability of the Jungck-Mann iteration scheme for approximating fixed points of operators in b-metric spaces. It defines the Jungck-Mann iterative procedure and establishes conditions for its stability. Specifically, it proves that if two operators S and T satisfy a contractive condition in a b-metric space, and Sx converges to a coincidence point p of S and T using the Jungck-Mann scheme, then any perturbed sequence Sy will also converge to p as the perturbations go to zero. The stability result relies on deriving inequalities relating the distances between iterates.

A common random fixed point theorem for rational inequality in hilbert space

This document presents a common random fixed point theorem for four continuous random operators defined on a non-empty closed subset of a separable Hilbert space. It begins with introducing basic concepts such as separable Hilbert spaces, random operators, and common random fixed points. It then defines a condition (A) that the four mappings must satisfy. The main result is Theorem 2.1, which proves the existence of a unique common random fixed point for the four operators under condition (A) and a rational inequality condition. The proof constructs a sequence of measurable functions and shows it converges to the common random fixed point. This establishes the common random fixed point theorem for these operators.

Existence of positive solutions for fractional q-difference equations involvi...

The existence of positive solutions is considered for a fractional q-difference equation with pLaplacian operator in this article. By employing the Avery-Henderson fixed point theorem, a new result is obtained
for the boundary value problems.

17 16512 32451-1-sm (edit ari)

This paper deals with the problem of undesired memory effects in nonlinear digital filters owing to the influence of past excitations on future outputs. The nonlinearities under consideration cover the usual types of overflow arithmetic employed in practice. Based on the Hankel norm performance, a new criterion is proposed to ensure the reduction of undesired memory effects in digital filters with overflow arithmetic. In absence of external input, the nonexistence of overflow oscillations is also confirmed by the proposed criterion. A numerical example together with simulation result showing the effectiveness of the criterion is given.

17 16512 32451-1-sm (edit ari)

This paper deals with the problem of undesired memory effects in nonlinear digital filters owing to the influence of past excitations on future outputs. The nonlinearities under consideration cover the usual types of overflow arithmetic employed in practice. Based on the Hankel norm performance, a new criterion is proposed to ensure the reduction of undesired memory effects in digital filters with overflow arithmetic. In absence of external input, the nonexistence of overflow oscillations is also confirmed by the proposed criterion. A numerical example together with simulation result showing the effectiveness of the criterion is given.

Computing the masses of hyperons and charmed baryons from Lattice QCD

Poster presented at the Computational Sciences 2013 Conference (Winner of poster competition). We present results on the masses of all forty light, strange and charm baryons from Lattice QCD simulations, focusing particularly on the computational aspects and requirements of such calculations.

On a Deterministic Property of the Category of k-almost Primes: A Determinist...

In this paper based on a sort of linear function, a deterministic and simple algorithm with an algebraic structure is presented for calculating all (and only) k-almost primes (where ∃n∊ℕ, 1 ≤ k ≤ n) in certain intervals. A theorem has been proven showing a new deterministic property of the category of k-almost primes. Through a linear function that we obtain, an equivalent redefinition of the k-almost primes with an algebraic characteristic is identified. Moreover, as an outcome of our function’s property some equalities which contain new information about the k-almost primes (including primes) are presented.
Comments: Accepted and presented article in the 11th ANTS , Korea, 2014. The 11th ANTS is one of international satellite conferences of ICM 2014:The 27th International Congress of Mathematicians, Korea. (Expanded version)
Copyright: CC Attribution-NonCommercial-NoDerivs 4.0 International
License URL: https://creativecommons.org/licenses/by-nc-nd/4.0/

Adaptive Restore algorithm & importance Monte Carlo

Talk given at the SMC 2024 workshop, ICMS, Edinburgh, Scotland

A kernel-free particle method: Smile Problem Resolved

The smile calibration problem is a mathematical conundrum in finance that has challenged quantitative analysts for decades. Through his research, Aitor Muguruza has discovered a novel resolution to this classic problem.

Radiation effects on heat and mass transfer of a mhd

IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology

Metodo Monte Carlo -Wang Landau

Metodo Monte Carlo -Wang Landau

C024015024

C024015024

Estimating structured vector autoregressive models

Estimating structured vector autoregressive models

A New Enhanced Method of Non Parametric power spectrum Estimation.

A New Enhanced Method of Non Parametric power spectrum Estimation.

On observer design methods for a

On observer design methods for a

A05920109

A05920109

Efficient Simulations for Contamination of Groundwater Aquifers under Uncerta...

Efficient Simulations for Contamination of Groundwater Aquifers under Uncerta...

Conference ppt

Conference ppt

Finite frequency H∞ control for wind turbine systems in T-S form

Finite frequency H∞ control for wind turbine systems in T-S form

Response Surface in Tensor Train format for Uncertainty Quantification

Response Surface in Tensor Train format for Uncertainty Quantification

Stability of Iteration for Some General Operators in b-Metric

Stability of Iteration for Some General Operators in b-Metric

A common random fixed point theorem for rational inequality in hilbert space

A common random fixed point theorem for rational inequality in hilbert space

Existence of positive solutions for fractional q-difference equations involvi...

Existence of positive solutions for fractional q-difference equations involvi...

17 16512 32451-1-sm (edit ari)

17 16512 32451-1-sm (edit ari)

17 16512 32451-1-sm (edit ari)

17 16512 32451-1-sm (edit ari)

Computing the masses of hyperons and charmed baryons from Lattice QCD

Computing the masses of hyperons and charmed baryons from Lattice QCD

On a Deterministic Property of the Category of k-almost Primes: A Determinist...

On a Deterministic Property of the Category of k-almost Primes: A Determinist...

Adaptive Restore algorithm & importance Monte Carlo

Adaptive Restore algorithm & importance Monte Carlo

A kernel-free particle method: Smile Problem Resolved

A kernel-free particle method: Smile Problem Resolved

Radiation effects on heat and mass transfer of a mhd

Radiation effects on heat and mass transfer of a mhd

量子アニーリングの研究開発最前線

2017年7月29日に開催された、第14回 Machine Learning 15minutes!にて使用したスライドです。
https://machine-learning15minutes.connpass.com/event/57907/
このスライドは、下記のスライドの短時間バージョンとなっています。
https://www.slideshare.net/shu-t/ss-75844478
こちらは、過去の私の量子アニーリングに関する研究スライドです。
https://www.slideshare.net/shu-t/ss-57178026
http://www.slideshare.net/shu-t/qit32
http://www.slideshare.net/shu-t/uai2009-ktm-jpn
http://www.slideshare.net/shu-t/neurocomputing-121523slideshare

量子アニーリングのこれまでとこれから -- ハード・ソフト・アプリ三方向からの協調的展開 --

2017年5月9日に開催された、第19回 全脳アーキテクチャ勉強会 ～ 脳・人工知能とアナログ計算・量子計算(NPO 法人 全脳アーキテクチャ・イニシアティブ主催)にて使用したスライドです。非専門家向けの講演です。
https://wba-meetup.doorkeeper.jp/events/59985
こちらは、過去の私の量子アニーリングに関する研究スライドです。
https://www.slideshare.net/shu-t/ss-57178026
http://www.slideshare.net/shu-t/qit32
http://www.slideshare.net/shu-t/uai2009-ktm-jpn
http://www.slideshare.net/shu-t/neurocomputing-121523slideshare

次世代量子情報技術 量子アニーリングが拓く新時代 -- 情報処理と物理学のハーモニー --

2016年１月15日に開催された、RCO Study Night "RCOにおける機械学習と次世代量子情報処理「量子アニーリング」"にて使用したスライドについて、web 公開版用に修正を加えたものです。非専門家向けの講演です。
https://atnd.org/events/73404
こちらは、過去の私の量子アニーリングに関する研究スライドです。
http://www.slideshare.net/shu-t/qit32
http://www.slideshare.net/shu-t/uai2009-ktm-jpn
http://www.slideshare.net/shu-t/neurocomputing-121523slideshare
なお、画像は、pixabay.com等、コピーライトフリーのサイトに掲載されているものを用いました。

量子アニーリングを用いたクラスタ分析 (QIT32)

2015年５月25日、第32回量子情報技術研究会(QIT32)にて、「量子アニーリングを用いたクラスタ分析」の口頭講演を行いました。講演概要は、
http://www.shutanaka.com/papers_files/ShuTanaka_QIT32.pdf
にあります。
本発表は以下の論文に基づいています。
http://www.cs.mcgill.ca/~uai2009/papers/UAI2009_0019_71a78b4a22a4d622ab48f2e556359e6c.pdf
http://www.cs.mcgill.ca/~uai2009/papers/UAI2009_0061_3cf8f564c6b5b6a22bd783669917c4c6.pdf
http://www.sciencedirect.com/science/article/pii/S0925231213005535
また、上記論文のプレプリント版は
http://arxiv.org/abs/0905.3527
http://arxiv.org/abs/0905.3528
http://arxiv.org/abs/1305.4325
です。

２次元可解量子系のエンタングルメント特性

2015年２月20日、京都大学大学院 人間・環境学研究科 相関環境学専攻にてセミナー発表いたしました。
本発表は以下の論文に基づいています。
http://iopscience.iop.org/1751-8121/43/25/255303
http://prb.aps.org/abstract/PRB/v84/i24/e245128
http://pra.aps.org/abstract/PRA/v86/i3/e032326
https://www.jstage.jst.go.jp/article/iis/19/1/19_IIS190115/_article
プレプリントバージョンは、以下のサイトから閲覧できます。
http://arxiv.org/abs/1003.2007
http://arxiv.org/abs/1107.3888
http://arxiv.org/abs/1207.6752
http://arxiv.org/abs/1307.1939

量子アニーリングを用いたクラスタ分析

Googleの栗原賢一さん、東京大学の宮下精二先生との共同研究論文 "Quantum Annealing for Clustering"の解説スライドです。
論文は以下からダウンロードできます。
Quantum Annealing for Clustering
http://www.cs.mcgill.ca/~uai2009/papers/UAI2009_0019_71a78b4a22a4d622ab48f2e556359e6c.pdf
以下は日本語の解説です。
量子アニーリング法を用いたクラスタ分析
http://www.shutanaka.com/papers_files/ShuTanaka_DEXSMI_10.pdf

量子アニーリングの研究開発最前線

量子アニーリングの研究開発最前線

量子アニーリングのこれまでとこれから -- ハード・ソフト・アプリ三方向からの協調的展開 --

量子アニーリングのこれまでとこれから -- ハード・ソフト・アプリ三方向からの協調的展開 --

次世代量子情報技術 量子アニーリングが拓く新時代 -- 情報処理と物理学のハーモニー --

次世代量子情報技術 量子アニーリングが拓く新時代 -- 情報処理と物理学のハーモニー --

量子アニーリングを用いたクラスタ分析 (QIT32)

量子アニーリングを用いたクラスタ分析 (QIT32)

２次元可解量子系のエンタングルメント特性

２次元可解量子系のエンタングルメント特性

量子アニーリングを用いたクラスタ分析

量子アニーリングを用いたクラスタ分析

Taking AI to the Next Level in Manufacturing.pdf

Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.

5th LF Energy Power Grid Model Meet-up Slides

5th Power Grid Model Meet-up
It is with great pleasure that we extend to you an invitation to the 5th Power Grid Model Meet-up, scheduled for 6th June 2024. This event will adopt a hybrid format, allowing participants to join us either through an online Mircosoft Teams session or in person at TU/e located at Den Dolech 2, Eindhoven, Netherlands. The meet-up will be hosted by Eindhoven University of Technology (TU/e), a research university specializing in engineering science & technology.
Power Grid Model
The global energy transition is placing new and unprecedented demands on Distribution System Operators (DSOs). Alongside upgrades to grid capacity, processes such as digitization, capacity optimization, and congestion management are becoming vital for delivering reliable services.
Power Grid Model is an open source project from Linux Foundation Energy and provides a calculation engine that is increasingly essential for DSOs. It offers a standards-based foundation enabling real-time power systems analysis, simulations of electrical power grids, and sophisticated what-if analysis. In addition, it enables in-depth studies and analysis of the electrical power grid’s behavior and performance. This comprehensive model incorporates essential factors such as power generation capacity, electrical losses, voltage levels, power flows, and system stability.
Power Grid Model is currently being applied in a wide variety of use cases, including grid planning, expansion, reliability, and congestion studies. It can also help in analyzing the impact of renewable energy integration, assessing the effects of disturbances or faults, and developing strategies for grid control and optimization.
What to expect
For the upcoming meetup we are organizing, we have an exciting lineup of activities planned:
-Insightful presentations covering two practical applications of the Power Grid Model.
-An update on the latest advancements in Power Grid -Model technology during the first and second quarters of 2024.
-An interactive brainstorming session to discuss and propose new feature requests.
-An opportunity to connect with fellow Power Grid Model enthusiasts and users.

Main news related to the CCS TSI 2023 (2023/1695)

An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .

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- 1. Quantum Annealing for Dirichlet Process Mixture Models with Applications to Network Clustering Issei Sato, Shu Tanaka, Kenichi Kurihara, Seiji Miyashita, and Hiroshi Nakagawa Neurocomputing 121, 523 (2013)
- 2. Main Results Diff. of log-likelihood Better We considered the eﬃciency of quantum annealing method for Dirichlet process mixture models. In this study, Monte Carlo simulation was performed. 21300 Wikivote 21200 21100 21000 2.5 3 3.5 4 4.5 5 0 - We constructed a method to apply quantum annealing to network clustering. - Quantum annealing succeeded to obtain a better solution than conventional methods. - The number of classes can be changed. (cf. K. Kurihara et al. and I. Sato et al., UAI2009) K. Kurihara et al., I. Sato et al., Proceedings of UAI2009.
- 3. Background Optimization problem To find the state (best solution) where the real-valued cost function is minimized. If the size of problem is small, we can easily obtain the best solution by brute-force calculation. However... if the size of problem is large, we cannot obtain the best solution by brute-force calculation in practice. We should develop methods to obtain the best solution (at least, better solution) eﬃciently.
- 4. Background Cost function of most optimization problems can be represented by Hamiltonian of classical discrete spin systems. We can use the knowledge of statistical physics. To find the state where the cost function is minimized. To find the ground state of the Hamiltonian. Simulated annealing (SA) By decreasing the temperature (thermal fluctuation) gradually, the ground state of the Hamiltonian is obtained. S. Kirkpatrick, C. D. Gelatte, and M. P. Vecchi, Science, 220, 671 (1983). SA can be adopted to both stochastic methods such as Monte Carlo method and deterministic method.
- 5. Background Quantum annealing (QA) By decreasing the quantum fluctuation gradually, the ground state of the Hamiltonian is obtained. T. Kadowaki and H. Nishimori, Phys. Rev. E, 58, 5355 (1998). E. Farhi, J. Goldstone, S. Gutmann, J. Lapan, A. Lundgren, and D. Preda, Science, 292, 472 (2001). G. E. Santoro, R. Martonak, E. Tosatti, and R. Car, Science, 295, 2427 (2002). Review articles G. E. Santoro and E. Tosatti, J. Phys. A: Math. Gen., 39, R393 (2006). A. Das and B. K. Chakrabarti, Rev. Mod. Phys., 80, 1061 (2008). S. Tanaka and R. Tamura, Kinki University Series on Quantum Computing Series "Lectures on Quantum Computing, Thermodynamics and Statistical Physics" (2012). QA is better than SA?
- 6. What is CRP?
- 7. Chinese Restaurant Process (CRP) Table (data class) Restaurant (entire set) 1 1 2 3 2 4 5 3 Customer (data point) Chinese Restaurant Process (CRP) assigns a probability for the seating arrangement of the customers.
- 8. Chinese Restaurant Process (CRP) Seating arrangement of the customers: Z = customer i sits at the k-th table: zi = k N {zi }i=1 N: the number of customers When customer i enters a restaurant with K occupied tables at which other customers are already seated, customer i sits at a table with the following probability: (k-th occupied table) +N 1 p(zi |Zzi ; ) Nk +N 1 (new unoccupied table) Nk: the number of customers sitting at the k-th table : hyper parameter of the CRP The log-likelihood of Z is given by p(Z) = K(Z) K(Z) N =1 (N + ) (Nk k=1 1)!
- 10. Quantum annealing for CRP (QACRP) QACRP uses multiple restaurants (m restaurants). customer i sits at the k-th table in the j-th restaurant: zj,i = k Seating arrangement of the customers in the j-th restaurant: Zj = {zj,i } In the j-th restaurant, when customer i enters a restaurant with K occupied tables at which other customers are already seated, customer i sits at a table with the following probability: Nj,k +N 1 /m (k-th occupied table) m pQA (zj,i | {Zd }d=1 {zj,i } ; , ) e (cj,k (i)+c+ (i))f ( , ) j,k /m +N 1 : inverse temperature (thermal fluctuation) : quantum fluctuation (new unoccupied table)
- 11. Quantum annealing for CRP (QACRP) /m Nj,k +N 1 e (cj,k (i)+c+ (i))f ( , ) j,k (k-th occupied table) m pQA (zj,i | {Zd }d=1 {zj,i } ; , ) /m (new unoccupied table) +N 1 c± (i) : the number of customers who sit at the k-th table in the j-th j,k restaurant and share tables with customer i in the (j ± 1)-th restaurant. j-1-th CRP 1 1 2 j+1-th CRP j-th CRP 3 2 4 5 3 1 1 4 3 2 5 3 2 1 3 4 1 2 5 2 The above fact will be proven in the following. 3
- 12. Quantum annealing for CRP (QACRP) Bit matrix representation for CRP A bit matrix B : adjacency matrix of customers 1 1 2 3 1 2 4 3 5 4 5 B Seating conditions ˜ 2 3 4 5 1 1 0 1 0 1 1 0 1 0 0 0 1 0 1 1 1 0 1 0 0 0 1 0 1 = N i=1 N n=1 ˜i,n Bi,n = Bn,i Bi,i = 1 (i = 1, 2, · · · , N ) i, , Bi /|Bi | · B /|B | = 1 or 0 Sitting arrangement can be represented by the Ising model with constraints.
- 13. Quantum annealing for CRP (QACRP) Bit matrix representation for CRP 1 1 2 4 3 2 2 1 2 1 1 0 1 0 0 customers who share a 1 0 table with customer 2. 1 4 3 3 4 5 5 1 1 1 1 0 1 0 0 1 0 0 0 1 1 0 1 1 0 1 0 0 1 0 0 0 0 0 0 a set of the states that customer 2 can take under the seating conditions. 3 4 5 1 1 0 1 0 1 1 0 1 0 0 0 1 0 1 1 1 0 1 0 0 0 1 0 1 1 1 5 2 2 3 4 5 1 0 1 0 0 1 0 1 0 1 0 1 0 1 0 1 2 3 4 5
- 14. Quantum annealing for CRP (QACRP) Density matrix representation for “classical” CRP Hc = diag[E( E( ( ) )= p( ) = (1) ), E( ln p( ( ) (2) ) + T e ), · · · E( ( ) T e Hc =: T ) )] ˜ ( ) Hc (2 N2 ˜ e Hc Zc Sitting arrangement can be represented by the Ising model with constraints.
- 15. Quantum annealing for CRP (QACRP) Formulation for quantum CRP H = Hc + Hq Hc : classical CRP Hq : quantum fluctuation T pQA ( ; , ) = Classical CRP p(˜i | ˜i ) = p(zi |Zzi ; ) e (Hc +Hq ) Te T ˜i e (Hc +Hq ) Hc T e Hc Nk +N 1 (k-th occupied table) +N 1 (new unoccupied table)
- 16. Quantum annealing for CRP (QACRP) Formulation for quantum CRP H = Hc + Hq Hc : classical CRP Hq : quantum fluctuation T pQA ( ; , ) = e (Hc +Hq ) Te Quantum CRP (Hc +Hq ) T pQA (˜i | ˜i ; , ) = ˜i e (Hc +Hq ) Te (Hc +Hq ) Transverse field as a quantum fluctuation N Hq = N x i,n , i=1 n=1 E= 1 0 0 1 , x = 0 1 1 0
- 17. Quantum annealing for CRP (QACRP) Approximation inference for QACRP T pQA ( ; , ) = e (Hc +Hq ) Te = (Hc +Hq ) pQA j (j ST ( , 2) 2, · · · m pQA ST ( 1 , 2, · · · , m; , )= N j+1 ) e , E( j=1 f ( , ) = 2 ln coth s( j , By the Suzuki-Trotter decomposition, pQA can be approximately expressed by the classical CRP. m; , )+O ef ( , )s( Z( , ) j )/m m N (˜j,i,n , ˜j+1,i,n ) = i=1 n=1 2N Z( , ) = sinh m e E( ) m 2 m j , j+1 )
- 18. Experiments Network model & dataset Citeseer citation network dataset for 2110 papers. 527 I. Sato et al. / Neurocomputing 121 (2013) 523–531 . (a) Social network (assortive network), (b) election network (disassortative network) and (c) citation network (mixture of assortative ning CRPs in which sj ðj ¼ 1; …; mÞ ment of the j-th CRP and represents ~ espond Bj;i;n ¼ 1 to s j;i;n ¼ ð1; 0Þ⊤ and means that we can represent Bj as the following121 (2013) 523–531 eurocomputing theorem: (10) is approximated by the Suzuki– ! β2 …; sm ; β; ΓÞ þ O ; m 1 e−β=mEðsj Þ ef ðβ;ΓÞsðsj ;sjþ1 Þ ; ¼ 1 Zðβ; ΓÞ ð15Þ m ∏ ð16Þ Netscience coauthorship network of regarded as a similarity function between the j-th and (j+1)-th bit matrices. If they are the same matrices, then sðs ; s Þ ¼ N . In scientists working on a network Eq. (2), log p ðs Þ corresponds to log e =Z and the regularizer term f Á Rðs ; …; s Þ is log ∏ e ¼ f ðβ; sðs ; s Þ. thatΓÞ∑ inference for scientists. has 1589 Note that we aim at deriving the approximation SA 1 −β=mEðsj Þ j m m f ðβ;ΓÞsðsj ;sjþ1 Þ j¼1 527 j 2 jþ1 m j¼1 j jþ1 pQA ðs i jss i ; β; ΓÞ in Eq. (13). Using Theorem 3.1, we can derive ~ ~ Eq. (4) as the approximation inference. The details of the derivation are provided in Appendix B. Wikivote a bipertite network constructed 4. Experiments using QA to a DPM We evaluated QA in a real application. We applied administrator elections. model for clustering vertices in a network where a seating 7115 Wikipedia users. arrangement of the CRP indicates a network partition. ples of network structures. (a) Social network (assortive network), (b) election network (disassortative network) and (c) citation network (mixture of assortative
- 19. Experiments Annealing schedule m : Trotter number, the number of replicas; m = 16 We tested several schedules of inverse temperature. ln(1 + t) 0 t 0t 0 = 0 = 0.2m, 0.4m, 0.6m t : t-th iteration. = 0.4m t is a better schedule in SA (MAP estimation). T = 0 m t is a schedule of quantum fluctuation. T : Total number of iterations
- 20. Diff. of log-likelihood Better Results 21300 Wikivote 21200 21100 21000 2.5 3 3.5 4 4.5 0 Lmax : the maximum log-likelihood of the beam search Beam Lmax : the maximum log-likelihood of 16 CRPs in SA 16SAs 5
- 21. Diff. of log-likelihood Results Citeseer 1600 1400 1200 Diff. of log-likelihood 1.5 2.5 3 Netscience We consider multiple running CRPs in which sj ðj ¼ 1; …; mÞ indicates the seating arrangement of the j-th CRP and represents ~ the j-th bit matrix Bj . We correspond Bj;i;n ¼ 1 to s j;i;n ¼ ð1; 0Þ⊤ and ⊤ Bj;i;n ¼ 0 to s j;i;n ¼ ð0; 1Þ , which means that we can represent Bj as ~ sj by using Eq. (5). We derive the following theorem: 600 500 1 Theorem 3.1. Sato ðs;al. ΓÞ in Eq. (10) is approximated by the Suzuki– I. pQA et β; / Neurocomputing 121 (2013) 523–531 Trotter expansion as2.5 follows: 3 1.5 2 0 pQA ðs; β; ΓÞ ¼ 21300 1 ⊤ −βðHc þHq Þ s e s Z Wikivote ¼ ∑ pQA−ST ðs; s2 ; …; sm ; β; ΓÞ þ O sj ðj≥2Þ 21200 2 ! β ; m pQA−ST ðs1 ; s2 ; …; sm ; β; ΓÞ 4. Experiments ð16Þ We evaluated QA in a real application. We applied QA to a DP model for clustering vertices in a network where a seati arrangement of the CRP indicates a network partition. 2.5 1 e−β=mEðsj Þ ef ðβ;ΓÞsðsj ;sjþ1 Þ ; Zðβ; ΓÞ j¼1 m ¼ ∏ regarded as a similarity function between the j-th and (j+1)-th matrices. If they are the same matrices, then sðsj ; sjþ1 Þ ¼ N 2 . Eq. (2), log pSA ðsj Þ corresponds to log e−β=mEðsj Þ =Z and the regulari term f Á Rðs1 ; …; sm Þ is log ∏m 1 ef ðβ;ΓÞsðsj ;sjþ1 Þ ¼ f ðβ; ΓÞ∑m 1 sðsj ; sjþ j¼ j¼ Note that we aim at deriving the approximation inference pQA ðs i jss i ; β; ΓÞ in Eq. (13). Using Theorem 3.1, we can der ~ ~ 527 Eq. (4) as the approximation inference. The details of the deriv tion are provided in Appendix B. ð15Þ where we rewrite s as s1 , and 21100 21000 I. Sato et al. / Neurocomputing 121 (2013) 523–531 3.5 Fig. 5. Examples of network structures. (a) Social network (assortive network), (b) election network (disassortative network) and (c) citation network (mixture of assorta and disassortative network). 0 700 400 Diff. of log-likelihood 2 Better solution can be obtained by QA. β Γ ; ð17Þ f ðβ; ΓÞ ¼ 2 Fig. 5. Examples of network structures. (a) Social network (assortive network), (b) election network (disassortative network) and (c) citation netwo log coth m 4.1. Network model and disassortative network). 3 3.5 4 N 4.5 5 N ~ ~ sðsj ; sjþ1 Þ ¼ 0∑ ∑ δðs j;i;n ; s jþ1;i;n Þ; ð18Þ We used the Newman model [17] for network modeling in t
- 22. Diff. of log-likelihood Results Citeseer 1600 SA(T=30,m=1) 13 sec. calc. time QA(T=30,m=16) 15 sec. 1400 16 SAs 1200 1600 SAs beam search QA(m=16) 35 30 57 37 # classes 1.5 2 2.5 3 3.5 Diff. of log-likelihood 0 700 SA(T=30,m=1) calc. time 600 25 sec. 16 SAs 500 400 QA(T=30,m=16) 22 sec. Netscience 1600 SAs beam search QA(m=16) 22 65 61 26 # classes 1 1.5 2 2.5 3 Diff. of log-likelihood 0 21300 SA(T=30,m=1) calc. time 21200 79 sec. 16 SAs 21100 21000 QA(T=30,m=16) 76 sec. Wikivote # classes 2.5 3 3.5 4 0 4.5 5 1600 SAs beam search QA(m=16) 8 8 27 8
- 23. Main Results Diff. of log-likelihood Better We considered the eﬃciency of quantum annealing method for Dirichlet process mixture models. In this study, Monte Carlo simulation was performed. 21300 Wikivote 21200 21100 21000 2.5 3 3.5 4 4.5 5 0 - We constructed a method to apply quantum annealing to network clustering. - Quantum annealing succeeded to obtain a better solution than conventional methods. - The number of classes can be changed. (cf. K. Kurihara et al. and I. Sato et al., UAI2009) K. Kurihara et al., I. Sato et al., Proceedings of UAI2009.
- 24. Thank you ! Issei Sato, Shu Tanaka, Kenichi Kurihara, Seiji Miyashita, and Hiroshi Nakagawa Neurocomputing 121, 523 (2013)