Ken Umeno | National Institute of Information and Communication Technology (original) (raw)

Papers by Ken Umeno

Research paper thumbnail of Towards international E-stat for monitoring the socio-economic activities across the globe

Abstract: We investigate relationship between annual electric power consumption per capita and gr... more Abstract: We investigate relationship between annual electric power consumption per capita and gross domestic production (GDP) per capita for 131 countries. We found that the relationship can be fitted with a power-law function. We examine the relationship for 47 prefectures in Japan. Furthermore, we investigate values of annual electric power production reported by four international organizations.

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Research paper thumbnail of Correlational properties of two-dimensional solvable chaos on the unit circle

Abstract: This article investigates correlational properties of two-dimensional chaotic maps on t... more Abstract: This article investigates correlational properties of two-dimensional chaotic maps on the unit circle. We give analytical forms of higher-order covariances. We derive the characteristic function of their simultaneous and lagged ergodic densities. We found that these characteristic functions are described by three types of two-dimensional Bessel functions. Higher-order covariances between x and y and those between y and y show non-positive values. Asymmetric features between cosine and sine functions are elucidated.

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Research paper thumbnail of A Class of Self-Trapped and Self-Focusing Wave Functions in Madelung Fluid Picture of A Single Free Particle Quantum System

Abstract: Using the Madelung fluid picture of Schr\" odinger equation for a single free particle ... more Abstract: Using the Madelung fluid picture of Schr\" odinger equation for a single free particle moving in one spatial dimension, we shall specify a class of wave functions whose quantum probability density is being trapped by the quantum potential it itself generates. The global convexity of the quantum potential generated by the initial self-trapped wave function will then be shown to further localize the quantum probability density through a self-generated focusing equation for a finite interval of time.

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Research paper thumbnail of Complex step-size dependences in tracking a simple two-body dynamics

Abstract: In molecular simulations, one of the most difficult points is to track the real dynamic... more Abstract: In molecular simulations, one of the most difficult points is to track the real dynamics of many-body systems from the first principle. The present study shows that step-size dependences have an unexpected effect on simulation results, even when we use the standard high-precision numerical integrators to apply to a simple system with a two-body interaction. The validity of our analysis is checked by the theory of adiabatic approximations.

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Research paper thumbnail of Chaotic Method for Generating q-Gaussian Random Variables

Abstract: This study proposes a pseudo random generator of q-Gaussian random variables for a rang... more Abstract: This study proposes a pseudo random generator of q-Gaussian random variables for a range of $ q $ values,-infinity< q< 3, based on deterministic map dynamics. Our method consists of orthogonal chaotic maps on the unit circle and map dynamics based on the tent map. We perform the q-Gaussian random generator for several values of q and conduct the Kolmogorov-Smirnov (KS) test.

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Research paper thumbnail of Application of Asynchronous Channels Method to the W-CDMA Systems

Abstract: We evaluate new interference suppression method that utilizes the effect of asynchronou... more Abstract: We evaluate new interference suppression method that utilizes the effect of asynchronous accesses in wireless telecommunication. The method is called as asynchronous channels (ACL), which can be applied to one of the present third generation standards, wideband code division multiple access (W-CDMA) systems. The simulation result shows that the system capacity gains up by 145% in band-unlimited rectangular pulse situations.

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Research paper thumbnail of 決定論的拡散のルベーグスペクトル解析

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Research paper thumbnail of 式部マップ II: Information Flow の再検討 (基研長期研究会 「複雑系 2」~ 物理から生物・進化・ゲームへ~, 研究会報告)

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Research paper thumbnail of 積分不可能系の離散化: 非平衡統計力学的側面と計理論的側面

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Research paper thumbnail of 力学系におけるフレーム問題: 計算可能性と積分可能性 (力学系と計算過程, 力学系アプローチの可能性と限界, 基研長期研究会 「複雑系 4」, 研究会報告)

系の複雑さを測る尺度は数学的に定義可能であるが, 実際に系を与えてその尺度を計算するのは難しいのは経験上よく知られていることである. だが, 本当にその複雑さを時間をかければ測定可能, もしくは... more 系の複雑さを測る尺度は数学的に定義可能であるが, 実際に系を与えてその尺度を計算するのは難しいのは経験上よく知られていることである. だが, 本当にその複雑さを時間をかければ測定可能, もしくは計算可能であるかというより根源的な問題となると, ほとんど研究が進んでいないのが現状である. 本報告では,〟-2 と"≧ 3 とで系の振る舞いが質的に変化をもたらす多体系としての力学系においてこの間題の研究の現状について報告者の知り得ることを記すこととする.

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Research paper thumbnail of < Poster Presentation 18> Inner Angles Made of Consecutive Three Points on a Circle for Chaotic and Random Series

These days, many properties of chaos are found. However, researches on methods to judge whether t... more These days, many properties of chaos are found. However, researches on methods to judge whether the obtained series are chaos or pure random still attracts many researchers' interests. Recently, an inner angle of triangle on a circle made of consecutive three points is found to show the difference between chaotic series and random series [1].

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Research paper thumbnail of セッション説明:「力学系理論, 可積分系, および, まとめ」(近可積分ハミルトン系の数理と応用)

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Research paper thumbnail of Performance of the recovered pseudo-noise binary sequences by independent component analysis for CDMA

Abstract—The performance of the spreading sequences obtained by recovering Pseudo-Noise binary se... more Abstract—The performance of the spreading sequences obtained by recovering Pseudo-Noise binary sequences by ICA for CDMA are investigated. We compared the property of these recovered sequences with the one of the original sequences and the Chebyshev chaotic sequences. For this purpose, we investigate correlation properties and calculate Bit Error Rates (BERs) analytically.

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Research paper thumbnail of Recovery of chaotic signals using on-line ICA algorithm

Abstract—Using chaotic signals, we evaluate the performance of the equivariant adaptive separatio... more Abstract—Using chaotic signals, we evaluate the performance of the equivariant adaptive separation via independence (EASI) algorithm. We found that the EASI algorithm in fixed-point (16-bit) arithmetic can recover the chaotic signals successfully as well as the algorithm in floating-point arithmetic. This suggests that the EASI algorithm is suitable for hardware implementation.

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Research paper thumbnail of Independent Component Analysis of Mixed Chaotic Signals for Communications Systems

Blind source separation of mixed chaotic signals is discussed with a possibility of application o... more Blind source separation of mixed chaotic signals is discussed with a possibility of application of independent component analysis for new type of asymmetric communications systems where blind receiver wihout decoding (despreading) sequence can decode from mixtures of chaotic signals by independent component analysis and symbolic dynamics correspondence.

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Research paper thumbnail of Key exchage by Chebyshev polynomials module 2^w

We show that Chebyshev polynomials of odd degree are permutable polynomials module 2^w. We use th... more We show that Chebyshev polynomials of odd degree are permutable polynomials module 2^w. We use this fact to construct a new key exchange algorithm.

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Research paper thumbnail of Performance of Chaotic Monte Carlo Computation and Chaos Codes for Communications: Theory and Experiments

A class of integrands which admit chaos-based Monte Carlo integration with O(1/N) mean error (sup... more A class of integrands which admit chaos-based Monte Carlo integration with O(1/N) mean error (superefficiency) [Umeno, K. (2000) Jpn. J. Appl. Phys., 39, 1442–1456] is completely characterized in terms of Lebesgue spectrum of ergodic dynamical systems. This Lebesgue spectrum characterization enables us to have general superefficiency for general integrand in chaotic Monte Carlo computation.

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Research paper thumbnail of Design of Spread-Spectrum Sequences Using Chaotic Dynamical Systemsand Ergodic Theory

IEEE Transactions on …, Jan 1, 2001

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Research paper thumbnail of Method of constructing exactly solvable chaos

Physical Review E, Jan 1, 1997

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Research paper thumbnail of Superposition of chaotic processes with convergence to Lévy's stable law

Physical Review E, Jan 1, 1998

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Research paper thumbnail of Towards international E-stat for monitoring the socio-economic activities across the globe

Abstract: We investigate relationship between annual electric power consumption per capita and gr... more Abstract: We investigate relationship between annual electric power consumption per capita and gross domestic production (GDP) per capita for 131 countries. We found that the relationship can be fitted with a power-law function. We examine the relationship for 47 prefectures in Japan. Furthermore, we investigate values of annual electric power production reported by four international organizations.

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Research paper thumbnail of Correlational properties of two-dimensional solvable chaos on the unit circle

Abstract: This article investigates correlational properties of two-dimensional chaotic maps on t... more Abstract: This article investigates correlational properties of two-dimensional chaotic maps on the unit circle. We give analytical forms of higher-order covariances. We derive the characteristic function of their simultaneous and lagged ergodic densities. We found that these characteristic functions are described by three types of two-dimensional Bessel functions. Higher-order covariances between x and y and those between y and y show non-positive values. Asymmetric features between cosine and sine functions are elucidated.

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Research paper thumbnail of A Class of Self-Trapped and Self-Focusing Wave Functions in Madelung Fluid Picture of A Single Free Particle Quantum System

Abstract: Using the Madelung fluid picture of Schr\" odinger equation for a single free particle ... more Abstract: Using the Madelung fluid picture of Schr\" odinger equation for a single free particle moving in one spatial dimension, we shall specify a class of wave functions whose quantum probability density is being trapped by the quantum potential it itself generates. The global convexity of the quantum potential generated by the initial self-trapped wave function will then be shown to further localize the quantum probability density through a self-generated focusing equation for a finite interval of time.

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Research paper thumbnail of Complex step-size dependences in tracking a simple two-body dynamics

Abstract: In molecular simulations, one of the most difficult points is to track the real dynamic... more Abstract: In molecular simulations, one of the most difficult points is to track the real dynamics of many-body systems from the first principle. The present study shows that step-size dependences have an unexpected effect on simulation results, even when we use the standard high-precision numerical integrators to apply to a simple system with a two-body interaction. The validity of our analysis is checked by the theory of adiabatic approximations.

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Research paper thumbnail of Chaotic Method for Generating q-Gaussian Random Variables

Abstract: This study proposes a pseudo random generator of q-Gaussian random variables for a rang... more Abstract: This study proposes a pseudo random generator of q-Gaussian random variables for a range of $ q $ values,-infinity< q< 3, based on deterministic map dynamics. Our method consists of orthogonal chaotic maps on the unit circle and map dynamics based on the tent map. We perform the q-Gaussian random generator for several values of q and conduct the Kolmogorov-Smirnov (KS) test.

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Research paper thumbnail of Application of Asynchronous Channels Method to the W-CDMA Systems

Abstract: We evaluate new interference suppression method that utilizes the effect of asynchronou... more Abstract: We evaluate new interference suppression method that utilizes the effect of asynchronous accesses in wireless telecommunication. The method is called as asynchronous channels (ACL), which can be applied to one of the present third generation standards, wideband code division multiple access (W-CDMA) systems. The simulation result shows that the system capacity gains up by 145% in band-unlimited rectangular pulse situations.

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Research paper thumbnail of 決定論的拡散のルベーグスペクトル解析

Bookmarks Related papers MentionsView impact

Research paper thumbnail of 式部マップ II: Information Flow の再検討 (基研長期研究会 「複雑系 2」~ 物理から生物・進化・ゲームへ~, 研究会報告)

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Research paper thumbnail of 積分不可能系の離散化: 非平衡統計力学的側面と計理論的側面

Bookmarks Related papers MentionsView impact

Research paper thumbnail of 力学系におけるフレーム問題: 計算可能性と積分可能性 (力学系と計算過程, 力学系アプローチの可能性と限界, 基研長期研究会 「複雑系 4」, 研究会報告)

系の複雑さを測る尺度は数学的に定義可能であるが, 実際に系を与えてその尺度を計算するのは難しいのは経験上よく知られていることである. だが, 本当にその複雑さを時間をかければ測定可能, もしくは... more 系の複雑さを測る尺度は数学的に定義可能であるが, 実際に系を与えてその尺度を計算するのは難しいのは経験上よく知られていることである. だが, 本当にその複雑さを時間をかければ測定可能, もしくは計算可能であるかというより根源的な問題となると, ほとんど研究が進んでいないのが現状である. 本報告では,〟-2 と"≧ 3 とで系の振る舞いが質的に変化をもたらす多体系としての力学系においてこの間題の研究の現状について報告者の知り得ることを記すこととする.

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Research paper thumbnail of < Poster Presentation 18> Inner Angles Made of Consecutive Three Points on a Circle for Chaotic and Random Series

These days, many properties of chaos are found. However, researches on methods to judge whether t... more These days, many properties of chaos are found. However, researches on methods to judge whether the obtained series are chaos or pure random still attracts many researchers' interests. Recently, an inner angle of triangle on a circle made of consecutive three points is found to show the difference between chaotic series and random series [1].

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Research paper thumbnail of セッション説明:「力学系理論, 可積分系, および, まとめ」(近可積分ハミルトン系の数理と応用)

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Research paper thumbnail of Performance of the recovered pseudo-noise binary sequences by independent component analysis for CDMA

Abstract—The performance of the spreading sequences obtained by recovering Pseudo-Noise binary se... more Abstract—The performance of the spreading sequences obtained by recovering Pseudo-Noise binary sequences by ICA for CDMA are investigated. We compared the property of these recovered sequences with the one of the original sequences and the Chebyshev chaotic sequences. For this purpose, we investigate correlation properties and calculate Bit Error Rates (BERs) analytically.

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Research paper thumbnail of Recovery of chaotic signals using on-line ICA algorithm

Abstract—Using chaotic signals, we evaluate the performance of the equivariant adaptive separatio... more Abstract—Using chaotic signals, we evaluate the performance of the equivariant adaptive separation via independence (EASI) algorithm. We found that the EASI algorithm in fixed-point (16-bit) arithmetic can recover the chaotic signals successfully as well as the algorithm in floating-point arithmetic. This suggests that the EASI algorithm is suitable for hardware implementation.

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Research paper thumbnail of Independent Component Analysis of Mixed Chaotic Signals for Communications Systems

Blind source separation of mixed chaotic signals is discussed with a possibility of application o... more Blind source separation of mixed chaotic signals is discussed with a possibility of application of independent component analysis for new type of asymmetric communications systems where blind receiver wihout decoding (despreading) sequence can decode from mixtures of chaotic signals by independent component analysis and symbolic dynamics correspondence.

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Research paper thumbnail of Key exchage by Chebyshev polynomials module 2^w

We show that Chebyshev polynomials of odd degree are permutable polynomials module 2^w. We use th... more We show that Chebyshev polynomials of odd degree are permutable polynomials module 2^w. We use this fact to construct a new key exchange algorithm.

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Research paper thumbnail of Performance of Chaotic Monte Carlo Computation and Chaos Codes for Communications: Theory and Experiments

A class of integrands which admit chaos-based Monte Carlo integration with O(1/N) mean error (sup... more A class of integrands which admit chaos-based Monte Carlo integration with O(1/N) mean error (superefficiency) [Umeno, K. (2000) Jpn. J. Appl. Phys., 39, 1442–1456] is completely characterized in terms of Lebesgue spectrum of ergodic dynamical systems. This Lebesgue spectrum characterization enables us to have general superefficiency for general integrand in chaotic Monte Carlo computation.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Design of Spread-Spectrum Sequences Using Chaotic Dynamical Systemsand Ergodic Theory

IEEE Transactions on …, Jan 1, 2001

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Research paper thumbnail of Method of constructing exactly solvable chaos

Physical Review E, Jan 1, 1997

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Superposition of chaotic processes with convergence to Lévy's stable law

Physical Review E, Jan 1, 1998

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Research paper thumbnail of Chaos Approach to Spectrum Management

Chaos (Random) Approach to spectrum management is discussed in connection with chaotic communicat... more Chaos (Random) Approach to spectrum management is discussed in connection with chaotic communications technology impacts about spectrum sharing.

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Research paper thumbnail of Chaos Approach to Spectrum Management

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