Kazuhiro Yamamoto

Thermal-noise-limited underground interferometer CLIO (2009)

Agatsuma, Kazuhiro, Arai, Koji, Fujimoto, Masa-Katsu, Kawamura, Seiji, Kuroda, Kazuaki, Miyakawa, Osamu, ...

We report on the current status of CLIO (Cryogenic Laser Interferometer Observatory), which is a prototype interferometer for LCGT (Large scale Cryogenic Gravitational-wave Telescope). LCGT is a...

Constraint on the growth factor of the cosmic structure from the damping of the baryon acoustic oscillation signature (2009)

Nakamura, Gen, Huetsi, Gert, Sato, Takahiro, Yamamoto, Kazuhiro

We determine a constraint on the growth factor by measuring the damping of the baryon acoustic oscillations in the matter power spectrum using the Sloan Digital Sky Survey luminous red galaxy sample....

Direct Measurement of Thermal Fluctuation of High-Q Pendulum (2009)

Agatsuma, Kazuhiro, Uchiyama, Takashi, Yamamoto, Kazuhiro, Ohashi, Masatake, Kawamura, Seiji, Miyoki, Shinji, ...

We achieved for the first time a direct measurement of the thermal fluctuation of a pendulum in an off-resonant region using a laser interferometric gravitational wave detector. These measurements...

Breaking the scale invariance of the primordial power spectrum in Horava-Lifshitz Cosmology (2009)

Yamamoto, Kazuhiro, Kobayashi, Tsutomu, Nakamura, Gen

We study the spectral tilt of primordial perturbations in Horava-Lifshitz cosmology. The uniform approximation, which is a generalization of the familiar Wentzel-Kramers-Brillouin (WKB) method, is...

Coating thermal noise of a finite-size cylindrical mirror (2009)

Somiya, Kentaro, Yamamoto, Kazuhiro

Thermal noise of a mirror is one of the limiting noise sources in the high-precision measurement such as gravitational-wave detection, and the modeling of thermal noise has been developed and refined...

DECIGO pathfinder (2009)

Ando, Masaki, Kawamura, Seiji, Sato, Shuichi, Nakamura, Takashi, Tsubono, Kimio, Araya, Akito, ...

DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory), which is a future space gravitational wave antenna. DECIGO is expected...

Coating thermal noise of a finite-size cylindrical mirror (2009)

Somiya, Kentaro, Yamamoto, Kazuhiro

Thermal noise of a mirror is one of the limiting noise sources in the high precision measurement such as gravitational-wave detection, and the modeling of thermal noise has been developed and refined...

Confronting the damping of the baryon acoustic oscillations with observation (2009)

Nomura, Hidenori, Yamamoto, Kazuhiro, Huetsi, Gert, Nishimichi, Takahiro

We investigate the damping of the baryon acoustic oscillations in the matter power spectrum due to the quasinonlinear clustering and redshift-space distortions by confronting the models with the...

Investigation of the Surrounding Environment's Influence on Gait Sensing Using a Plant as a Sensor (2009)

Shigeki Hirobayashi, Yusuke Tamura, Kazuhiro Yamamoto

Some animals and plants function as bioantennas in that changes in their surrounding environment produce variations in their bioelectric potentials. While the bioelectric potential is affected by...

Damping of the baryon acoustic oscillations in the matter power spectrum as a probe of the growth factor (2008)

Nomura, Hidenori, Yamamoto, Kazuhiro, Nishimichi, Takahiro

We investigate the damping of the baryon acoustic oscillations (BAO) signature in the matter power spectrum due to the quasi-nonlinear clustering of density perturbations. On the basis of the third...

Search for a Stochastic Background of 100-MHz GravitationalWaves with Laser Interferometers (2008)

Akutsu, Tomotada, Kawamura, Seiji, Nishizawa, Atsushi, Arai, Koji, Yamamoto, Kazuhiro, Tatsumi, Daisuke, ...

This Letter reports the results of a search for a stochastic background of gravitational waves (GW) at 100 MHz by laser interferometry. We have developed a GW detector, which is a pair of 75-cm...

DECIGO pathfinder (2008)

Ando, Masaki, Kawamura, Seiji, Nakamura, Takashi, Tsubono, Kimio, Tanaka, Takahiro, Funaki, Ikkoh, ...

DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected...

The Japanese space gravitational wave antenna; DECIGO (2008)

Kawamura, Seiji, Ando, Masaki, Nakamura, Takashi, Tsubono, Kimio, Tanaka, Takahiro, Funaki, Ikkoh, ...

DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. DECIGO is expected to open a new window of observation for gravitational...

Testing general relativity with the multipole spectra of the SDSS luminous red galaxies (2008)

Yamamoto, Kazuhiro, Sato, Takahiro, Huetsi, Gert

As a test of general relativity on cosmological scales, we measure the \gamma parameter for the growth rate of density perturbations using the redshift-space distortion of the luminous red galaxies...

Effect of energy deposited by cosmic-ray particles on interferometric gravitational wave detectors (2008)

Yamamoto, Kazuhiro, Hayakawa, Hideaki, Okada, Atsushi, Uchiyama, Takashi, Miyoki, Shinji, Ohashi, Masatake, ...

We investigated the noise of interferometric gravitational wave detectors due to heat energy deposited by cosmic-ray particles. We derived a general formula that describes the response of a mirror...

Search for a stochastic background of 100-MHz gravitational waves with laser interferometers (2008)

Akutsu, Tomotada, Kawamura, Seiji, Nishizawa, Atsushi, Arai, Koji, Yamamoto, Kazuhiro, Tatsumi, Daisuke, ...

This letter reports the results of a search for a stochastic background of gravitational waves (GW) at 100 MHz by laser interferometry. We have developed a GW detector, which is a pair of 75-cm...

Optimal Location of Two Laser-interferometric Detectors for Gravitational Wave Backgrounds at 100 MHz (2008)

Nishizawa, Atsushi, Kawamura, Seiji, Akutsu, Tomotada, Arai, Koji, Yamamoto, Kazuhiro, Tatsumi, Daisuke, ...

Recently, observational searches for gravitational wave background (GWB) have been developed and given constraints on the energy density of GWB in a broad range of frequencies. These constraints have...

Laser-interferometric detectors for gravitational wave backgrounds at 100 MHz: Detector design and sensitivity (2008)

Nishizawa, Atsushi, Kawamura, Seiji, Akutsu, Tomotada, Arai, Koji, Yamamoto, Kazuhiro, Tatsumi, Daisuke, ...

Recently, observational searches for gravitational wave background (GWB) have been developed and given direct and indirect constraints on the energy density of GWB in a broad range of frequencies....

Search for continuous gravitational waves from PSR J0835-4510 using CLIO data (2008)

Akutsu, Tomomi, Ando, Masaki, Haruyama, Tomiyoshi, Kanda, Nobuyuki, Kuroda, Kazuaki, Miyoki, Shinji, ...

We search for continuous gravitational waves from PSR J0835-4510 at twice its rotational frequency using CLIO (Cryogenic Laser Interferometric Observatory) in the Kamioka mine. In this search, we use...

Effect of energy deposited by cosmic-ray particles on interferometric gravitational wave detectors (2008)

Yamamoto, Kazuhiro, Hayakawa, Hideaki, Okada, Atsushi, Uchiyama, Takashi, Miyoki, Shinji, Ohashi, Masatake, ...

We investigated the noise of interferometric gravitational wave detectors due to heat energy deposited by cosmic-ray particles. We derived a general formula that describes the response of a mirror...

密度変化を考慮したモデルによる部分予混合雰囲気中の火炎の燃え拡がり解析 (2007)

緒方, 佳典, OGATA, Yoshinori, 山本, 和弘, YAMAMOTO, Kazuhiro, 山下, 博史, YAMASHITA, Hiroshi

In this study, we have numerically investigated flame spread over solid fuel in partially premixed atmospheres, which may occur under poorly ventilated conditions, forming the combustible mixtures of...

Simulation on Soot Oxidation with NO2 and O2 in a Diesel Particulate Filter (2007)

YAMAMOTO, Kazuhiro, SATAKE, Shingo, YAMASHITA, Hiroshi, OBUCHI, Akira, UCHISAWA, Junko

Although diesel engines have an advantage of low fuel consumption in comparison with gasoline engines, exhaust gas has more particulate matters (PM) including soot. As one of the key technologies, a...

Conduction Effect of Thermal Radiation in a Metal Shield Pipe in a Cryostat for a Cryogenic Interferometric Gravitational Wave Detector (2007)

Tomaru, Takayuki, Tokunari, Masao, Kuroda, Kazuaki, Uchiyama, Takashi, Okutomi, Akira, Ohashi, Masatake, ...

A large heat load caused by thermal radiation through a metal shield pipe was observed in a cooling test of a cryostat for a prototype of a cryogenic interferometric gravitational wave detector. The...

Astrophysical Condition on the attolensing as a possible probe for a modified gravity theory (2007)

Sato, Takahiro, Gunara, Bobby E., Yamamoto, Kazuhiro, Zen, Freddy P.

We investigate the wave effect in the gravitational lensing by a black hole with very tiny mass less than 10^-19 solar mass, which is called attolensing, motivated by a recent report that the lensing...

Laser-interferometric Detectors for Gravitational Wave Background at 100 MHz : Detector Design and Sensitivity (2007)

Nishizawa, Atsushi, Kawamura, Seiji, Akutsu, Tomotada, Arai, Koji, Yamamoto, Kazuhiro, Tatsumi, Daisuke, ...

Recently, observational searches for gravitational wave background (GWB) have developed and given direct and indirect constraints on the energy density of GWB in a broad range of frequencies. These...

OH-HCHO同時PLIF法による乱流予混合火炎の可視化と火炎構造 (2007)

山本, 和弘, YAMAMOTO, Kazuhiro, 大西, 將博, OHNISHI, Masahiro, 林, 直樹, HAYASHI, Naoki, ...

In this study, using simultaneous OH-HCHO PLIF (Planar Laser-Induced Fluorescence) technique, we have obtained instantaneous two-dimensional flame images to investigate highly turbulent premixed...

ディーゼル微粒子の堆積とフィルタの再生課程の数値解析 (2007)

佐竹, 真吾, SATAKE, Shingo, 山本, 和弘, YAMAMOTO, Kazuhiro, 山下, 博史, YAMASHITA, Hiroshi

Recently, more strict diesel particulate emissions standards are being set in many countries. To have an advantage of low fuel consumption in comparison with gasoline engines, several improvements...

Flow Field of Turbulent Premixed Combustion in a Cyclone-Jet Combustor (2007)

YAMAMOTO, Kazuhiro, INOUE, Satoshi, YAMASHITA, Hiroshi, SHIMOKURI, Daisuke, ISHIZUKA, Satoru

The flow field in highly turbulent premixed combustion has been examined, using a cyclone-jet combustor. The shear-strain rate is obtained by PIV system. Results show that, in combustion field, mean...

Characteristic Scales of Baryon Acoustic Oscillations from Perturbation Theory: Non-linearity and Redshift-Space Distortion Effects (2007)

Nishimichi, Takahiro, Ohmuro, Hiroshi, Nakamichi, Masashi, Taruya, Atsushi, Yahata, Kazuhiro, Shirata, Akihito, ...

An acoustic oscillation of the primeval photon-baryon fluid around the decoupling time imprints a characteristic scale in the galaxy distribution today, known as the baryon acoustic oscillation (BAO)...

Optimizing future imaging survey of galaxies to confront dark energy and modified gravity models (2007)

Yamamoto, Kazuhiro, Parkinson, David, Hamana, Takashi, Nichol, Robert C., Suto, Yasushi

We consider the extent to which future imaging surveys of galaxies can distinguish between dark energy and modified gravity models for the origin of the cosmic acceleration. Dynamical dark energy...

Current status of Japanese detectors (2007)

Tatsumi, Daisuke, Takahashi, Ryutaro, Arai, Koji, Nakagawa, Noriyasu, Agatsuma, Kazuhiro, Yamazaki, Toshitaka, ...

Current status of TAMA and CLIO detectors in Japan is reported in this article. These two interferometric gravitational-wave detectors are being developed for the large cryogenic gravitational wave...

乱流予混合火炎の燃焼診断に対するアセトン-OH同時PLIF計測手法の有効性の検討 (2007)

馬目, 聡, MANOME, Satoshi, 中村, 祐二, NAKAMURA, Yuji, 林, 直樹, HAYASHI, Naoki, ...

This paper described an availability of acetone-OH simultaneous PLIF scheme for combustion diagnostics on turbulent premixed flame. Distinctive signal gap is found between acetone (seeded in the...

部分予混合化によるPAHs抑制メカニズムの検討 (2006)

石井, 大祐, ISHII, Daisuke, 中村, 祐二, NAKAMURA, Yuji, 林, 直樹, HAYASHI, Naoki, ...

The depletion mechanism of polycyclic aromatic hydrocarbons (PAHs) in a partially-premixed methane-air counterflow flame is investigated. The oxygen added to fuel flow is varied in the range from...

The Behaviour of Scattered Plane Waves of Elastic Wave Equations and Applications to Scattering Theory (2006)

Yamamoto, Kazuhiro

In this paper we shall study singularities of scattered plane elastic waves by a convex obstacle. As an application we show a theorem on the position of singularities of the scattering kernel S(·,...

A theoretical approach to thermal noise caused by an inhomogeneously distributed loss -- Physical insight by the advanced modal expansion (2006)

Yamamoto, Kazuhiro, Ando, Masaki, Kawabe, Keita, Tsubono, Kimio

We modified the modal expansion, which is the traditional method used to calculate thermal noise. This advanced modal expansion provides physical insight about the discrepancy between the actual...

格子ボルツマン法による転炉内二次燃焼の解析 (2006)

古賀, 輝久, KOGA, Teruhisa, 山本, 和弘, YAMAMOTO, Kazuhiro, 岸本, 康夫, KISHIMOTO, Yasuo, ...

In this study, numerical simulation on fluid flow and secondary combustion reaction in a converter has been conducted, where CO formed from the high-temperature molten steel is reacted with oxygen....

Classical and quantum radiation from a moving charge in an expanding universe (2006)

Nomura, Hidenori, Sasaki, Misao, Yamamoto, Kazuhiro

We investigate photon emission from a moving particle in an expanding universe. This process is analogous to the radiation from an accelerated charge in the classical electromagnetic theory. Using...

メタン・空気予混合気の着火特性に関する詳細素反応機構を考慮した数値解析 (2006)

松山, 竜佐, MATSUYAMA, Ryusuke, 山下, 博史, YAMASHITA, Hiroshi, 山本, 和弘, YAMAMOTO, Kazuhiro

Ignition is a transient combustion phenomenon and one of the most difficult and complex problems, which include a lot of physical and chemical processes, so that it has not yet been explained...

Searching for modified gravity with baryon oscillations: from SDSS to wide field multiobject spectroscopy (WFMOS) (2006)

Yamamoto, Kazuhiro, Bassett, Bruce A., Nichol, Robert C., Suto, Yasushi, Yahata, Kazuhiro

We discuss how the baryon acoustic oscillation (BAO) signatures in the galaxy power spectrum can distinguish between modified gravity and the cosmological constant as the source of cosmic...

The finite source size effect and the wave optics in gravitational lensing (2006)

Matsunaga, Norihito, Yamamoto, Kazuhiro

We investigate the finite source size effect in the context of the wave optics in the gravitational lensing. The magnification of an extended source is presented in an analytic manner for the...

反応進行度とその勾配による非定常対向流予混合火炎の火炎構造の整理 (2006)

林, 直樹, HAYASHI, Naoki, 山下, 博史, YAMASHITA, Hiroshi, 中村, 祐二, NAKAMURA, Yuji, ...

Dominant parameters in unsteady flame structure of methane/air counterflow premixed flame are investigated by numerical simulation with detailed chemical kinetics model. Two boundary conditions are...

Measurement of the mechanical loss of a cooled reflective coating for gravitational wave detection (2006)

Yamamoto, Kazuhiro, Miyoki, Shinji, Uchiyama, Takashi, Ishitsuka, Hideki, Ohashi, Masatake, Kuroda, Kazuaki, ...

We have measured the mechanical loss of a dielectric multilayer reflective coating (ion-beam sputtered SiO$_2$ and Ta$_2$O$_5$) in cooled mirrors. The loss was nearly independent of the temperature...

二次元非定常予混合火炎に関する素反応機構による数値解析 (予混合火炎構造を支配する物質量としての反応進行度とその勾配の妥当性) (2005)

加藤, 敏宏, KATOH, Toshihiro, 林, 直樹, HAYASHI, Naoki, 山下, 博史, YAMASHITA, Hiroshi, ...

The flame structure of unsteady two-dimensional premixed flame is numerically simulated with elementary reaction mechanism. In order to investigate unsteady behavior, a sinusoidal fluctuation is...

乱流燃焼場のPIV計測と乱れスケールの算出 (2005)

山本, 和弘, YAMAMOTO, Kazuhiro, 井上, 聡, INOUE, Satoshi, 山下, 博史, YAMASHITA, Hiroshi, ...

We have investigated a turbulent combustion by PIV (Particle Image Velocimetry) technique. Comparing with LDV data, the validity of PIV measurement has been confirmed. Especially, the conditions of...

A Measurement of the Quadrupole Power Spectrum in the Clustering of the 2dF QSO Survey (2005)

Yamamoto, Kazuhiro, Nakamichi, Masashi, Kamino, Akinari, Bassett, Bruce A., Nishioka, Hiroaki

We report a measurement of the quadrupole power spectrum in the two degree field (2dF) QSO redshift (2QZ) survey. The analysis uses an algorithm parallel to that for the estimation of the standard...

Modulation of a Chirp Gravitational Wave from a Compact Binary due to Gravitational Lensing (2005)

Yamamoto, Kazuhiro

A possible wave effect in the gravitational lensing phenomenon is discussed. We consider the interference of two coherent gravitational waves of slightly different frequencies from a compact binary,...

Different effects of long- and short-acting loop diuretics on survival rate in Dahl high-salt heart failure model rats (2005)

Yoshida, Junichi, Yamamoto, Kazuhiro, Mano, Toshiaki, Sakata, Yasushi, Nishio, Mayu, Ohtani, Tomohito, ...

Objectives: We compared therapeutic effects of furosemide, a short-acting loop diuretic, and azosemide, a long-acting one, in hypertensive heart failure rats to test the hypothesis that long-acting...

Dark energy reflections in the redshift-space quadrupole (2004)

Yamamoto, Kazuhiro, Bassett, Bruce A., Nishioka, Hiroaki

We show that the redshift-space quadrupole will be a powerful tool for constraining dark energy even if the baryon oscillations are missing from the usual monopole power spectrum and even if bias is...

Combustion Simulation Using the Lattice Boltzmann Method (2004)

YAMAMOTO, Kazuhiro, HE, Xiaoyi, DOOLEN, Gary D.

Even though laser diagnostics have significantly improved and can obtain an instantaneous 2D flame image of the velocity field, it is still difficult to obtain data such as scalar flux or reaction...

Power Spectrum Analysis of the 2dF QSO Sample Revisited (2004)

Yamamoto, Kazuhiro

We revisit the power spectrum analysis of the complete sample of the two degree field (2dF) QSO redshift (2QZ) survey, as a complementary test of the work by Outram et al. (2003). A power spectrum...

N-Methylethanolamine attenuates cardiac fibrosis and improves diastolic function: inhibition of phospholipase D as a possible mechanism (2004)

Yamamoto, Kazuhiro, Takahashi, Yoshito, Mano, Toshiaki, Sakata, Yasushi, Nishikawa, Nagahiro, Yoshida, Junichi, ...

Aim Ventricular fibrosis is promoted by many effectors that chronically activate phospholipase D (PLD), and induces cardiac dysfunction and heart failure in cardiovascular diseases. Since...

Wave effect in gravitational lensing by a cosmic string (2003)

Yamamoto, Kazuhiro, Tsunoda, Keiji

The wave effect in the gravitational lensing phenomenon by a straight cosmic string is investigated. The interference pattern is expressed in terms of a simple formula. We demonstrate that...

Path Integral Formulation for Wave Effect in Multi-lens System (2003)

Yamamoto, Kazuhiro

A formula to investigate wave effect in multi-lens system is presented on the basis of path integral formalism by generalizing the work by Nakamura and Deguchi (1999). Wave effect of a system with...

燃料を添加した部分予混合雰囲気中の可燃性固体の燃え拡がり (2003)

山本, 和弘, YAMAMOTO, Kazuhiro, 瀬尾, 哲, SEO, Satoshi, 森, 幸一, MORI, Koichi, ...

Studies on downward flame spread over solid fuel are useful to understand complex two-phase non-premixed flames including fires. We investigate the flame spread in partially premixed atmospheres,...

Persistence of Laminar Flamelet Structure Under Highly Turbulent Combustion (2003)

YAMAMOTO, Kazuhiro, NISHIZAWA, Yasuki, ONUMA, Yoshiaki

We have investigated the premixed flame structure in highly turbulent flow with a cyclone-jet combustor. Based on the turbulent properties determined by Slot-Correlation method, the condition of Um...

Covariant Wigner Function Approach to the Boltzmann Equation for Mixing Fermions in Curved Spacetime (2003)

Yamamoto, Kazuhiro

Based on the covariant Wigner function approach we derive the quantum Boltzmann equation for fermions with flavor mixing in general curved spacetime. This work gives a rigorous theoretical framework...

可燃性固体の燃え拡がりに及ぼす周囲雰囲気の影響 (第2報, 希釈の影響と気相の温度測定) (2003)

山本, 和弘, YAMAMOTO, Kazuhiro, 森, 幸一, MORI, Koichi, 小沼, 義昭, ONUMA, Yoshiaki

To investigate effects of ambient atmosphere on flame spread, an experimental study has been conducted. The downward flame spread over solid fuel has been examined in a combustion chamber with a...

可燃性固体の燃え拡がりに対するモデルの検討 (2003)

山本, 和弘, YAMAMOTO, Kazuhiro

In this study, the model for flame spread over solid fuel is investigated. To re-examine the analytical solution by de Ris, our experimental data on flame temperature and flame spread rate are used,...

Temperatures of Positively and Negatively Stretched Flames (2003)

YAMAMOTO, Kazuhiro, ISHIZUKA, Satoru

Both tubular flame temperature and Bunsen flame temperature have been measured for lean methane, hydrogen and propane/air mixtures. These temperatures have been compared with the adiabatic flame...

Measuring Cosmological Parameters with the SDSS QSO Spatial Power Spectrum Analysis to Test the Cosmological Principle (2003)

Yamamoto, Kazuhiro

In this paper we emphasize the importance of the Sloan Digital Sky Survey (SDSS) QSO clustering statistics as a unique probe of the Universe. Because the complete SDSS QSO sample covers a quarter of...

Temocapril prevents transition to diastolic heart failure in rats even if initiated after appearance of LV hypertrophy and diastolic dysfunction (2003)

Sakata, Yasushi, Yamamoto, Kazuhiro, Mano, Toshiaki, Nishikawa, Nagahiro, Yoshida, Junichi, Miwa, Takeshi, ...

Objective: Congestive heart failure with left ventricular (LV) diastolic dysfunction and preserved systolic function, i.e. diastolic heart failure (DHF), is often observed in hypertensive patients....

Differential activation of matrix metalloproteinases in heart failure with and without ventricular dilatation (2003)

Nishikawa, Nagahiro, Yamamoto, Kazuhiro, Sakata, Yasushi, Mano, Toshiaki, Yoshida, Junichi, Miwa, Takeshi, ...

Objective: Remodeling of extracellular matrix (ECM) is considered to contribute to progression of left ventricular (LV) remodeling and matrix metalloproteinases (MMPs) play crucial roles in...

格子ボルツマン法による燃焼場の数値計算 (2002)

山本, 和弘, YAMAMOTO, Kazuhiro

For modeling turbulent combustion, numerous studies have been made. Even chemically non-reacting turbulent flows are complex phenomena, and chemical reactions make the problem more complicated. Due...

可燃性固体の燃え拡がりに及ぼす周囲雰囲気の影響 (周囲温度の影響と鉛直下方燃え拡がり限界酸素濃度) (2002)

山本, 和弘, YAMAMOTO, Kazuhiro, 森, 幸一, MORI, Koichi, 小沼, 義昭, ONUMA, Yoshiaki

The downward flame spread over solid fuel has been studied. Paper sheets are used as samples, and experiments are conducted in a combustion chamber with a vertical duct to obtain uniform ambient...

Optimal Weighting Scheme in Redshift-space Power Spectrum Analysis and a Prospect for Measuring the Cosmic Equation of State (2002)

Yamamoto, Kazuhiro

We develop a useful formula for power spectrum analysis for high and intermediate redshift galaxy samples, as an extension of the work by Feldman, Kaiser & Peacock (1994). An optimal weight factor,...

Cosmological Constraint from the 2dF QSO Spatial Power Spectrum (2002)

Yamamoto, Kazuhiro

In this paper we obtain constraints on the cosmological density parameters, \Omega_m and \Omega_b, by comparing the preliminary measurement of the QSO power spectrum from the two degree field QSO...

旋回噴流燃焼器を用いた強乱流予混合火炎の研究 (第3報, Slot-Correlation法による燃焼場の乱れスケールの計測) (2002)

山本, 和弘, YAMAMOTO, Kazuhiro, 西澤, 泰樹, NISHIZAWA, Yasuki, 小沼, 義昭, ONUMA, Yoshiaki

Premixed flames in highly turbulent flow have been investigated by a cyclone-jet combustor. The velocity field has been measured using LDV (laser-doppler velocimeter) to analyze the experimental...

強乱流予混合火炎の流れ場と構造 (2002)

山本, 和弘, YAMAMOTO, Kazuhiro, 西澤, 泰樹, NISHIZAWA, Yasuki

To examine the premixed flame structure in highly turbulent flow, by a cyclone-jet combustor, we have examined the flow field both in cold flow and in combustion field using LDV system. The...

Myocardial stiffness is determined by ventricular fibrosis, but not by compensatory or excessive hypertrophy in hypertensive heart (2002)

Yamamoto, Kazuhiro, Masuyama, Tohru, Sakata, Yasushi, Nishikawa, Nagahiro, Mano, Toshiaki, Yoshida, Junichi, ...

Objectives: Diastolic dysfunction that determines symptoms and prognosis in patients with systolic dysfunction causes heart failure even in the absence of systolic dysfunction. Our recent studies...

格子ガスオートマトン法による燃焼場の数値計算 (2001)

山本, 和弘, YAMAMOTO, Kazuhiro, 小沼, 義昭, ONUMA, Yoshiaki

Lattice Gas Automata (LGA) is an alternative approach for simulating fluids. The scheme of this discrete model is simple and easy for pararell computing. In this work, we simulate combustion filed by...

Feasibility of Probing Dark Energy with Strong Gravitational Lensing Systems -- Fisher-Matrix Approach -- (2001)

Yamamoto, Kazuhiro, Kadoya, Yasufum, Murata, Tsukasa, Futamase, Toshifumi

We assess the feasibility of probing dark energy with strong gravitational lensing systems. The capability of the method, which depends on the accuracy with which the lensing systems are modeled, is...

Cosmological constraint from QSO spatial power spectrum (2001)

Yamamoto, Kazuhiro

In this paper we consider constraints on the cosmological density parameters from the spatial power spectrum of QSOs. We first review an analytic approach to the spatial power spectrum of QSOs, then...

Possible Method to Reconstruct the Cosmic Equation of State from Strong Gravitational Lensing Systems (2001)

Yamamoto, Kazuhiro, Futamase, Toshifumi

A possible method to reconstruct the cosmic equation of state using strong gravitational lensing systems is proposed. The feasibility of the method is investigated by carrying out the reconstruction...

Explicit Derivation of the Fluctuation-Dissipation Relation of the Vacuum Noise in the N-dimensional de Sitter Spacetime (2001)

Murata, Tsukasa, Tsunoda, Keiji, Yamamoto, Kazuhiro

Motivated by a recent work by Terashima (Phys. Rev. D60 084001), we revisit the fluctuation-dissipation (FD) relation between the dissipative coefficient of a detector and the vacuum noise of fields...

Can Geometric Test Probe the Cosmic Equation of State ? (2001)

Yamamoto, Kazuhiro, Nishioka, Hiroaki

Feasibility of the geometric test as a probe of the cosmic equation of state of the dark energy is discussed assuming the future 2dF QSO sample. We examine sensitivity of the QSO two-point...

The effect of bias and redshift distortions on a geometric test for the cosmological constant (2000)

Yamamoto, Kazuhiro, Nishioka, Hiroaki, Taruya, Atsushi

We revisit the feasibility of a cosmological test with the geometric distortion focusing on an ambiguous factor of the evolution of bias. Starting from defining estimators for the spatial two-point...

Isodensity Statistics on Clustering of High-z Objects in Cosmological Redshift-spaces (2000)

Taruya, Atsushi, Yamamoto, Kazuhiro

We discuss the systematic effects arising from the cosmological redshift-space (geometric) distortion on the statistical analysis of isodensity contour using high-redshift catalogs. Especially, we...

Nonlinear Evolution of Very Small Scale Cosmological Baryon Perturbations at Recombination (2000)

Liu, Guo-Chin, Yamamoto, Kazuhiro, Sugiyama, Naoshi, Nishioka, Hiroaki

The evolution of baryon density perturbations on very small scales is investigated. In particular, the nonlinear growth induced by the radiation drag force from the shear velocity field on larger...

旋回噴流燃焼器を用いた強乱流予混合火炎の研究 (第2報, 静電探針を用いた火炎の微細構造の検討) (2000)

山本, 和弘, YAMAMOTO, Kazuhiro, 阿知波, 朝士, ACHIHA, Tomoshi, 小沼, 義昭, ONUMA, Yoshiaki

To examine flame structure in turbulent flow, we have established highly turbulent flames of a propane-air mixture in a cyclone-jet combustor, and have measured ion current by an electrostatic probe....

Roles of renin-angiotensin and endothelin systems in development of diastolic heart failure in hypertensive hearts (2000)

Yamamoto, Kazuhiro, Masuyama, Tohru, Sakata, Yasushi, Mano, Toshiaki, Nishikawa, Nagahiro, Kondo, Hiroya, ...

Objective: Although interest in diastolic heart failure is growing because of its clinical frequency, little is known about this type of heart failure. Our laboratory recently developed a diastolic...

Local neurohumoral regulation in the transition to isolated diastolic heart failure in hypertensive heart disease: absence of AT1 receptor downregulation and 'overdrive' of the endothelin system (2000)

Yamamoto, Kazuhiro, Masuyama, Tohru, Sakata, Yasushi, Doi, Reiko, Ono, Keiko, Mano, Toshiaki, ...

Objective: Although isolated diastolic heart failure with preserved left ventricular (LV) systolic function frequently occurs, regulation of local neurohumoral factors in the transition from...

Redshift-space Distortions of the Power Spectrum of Cosmological Objects on a Light Cone : Explicit Formulations and Theoretical Implications (1999)

Nishioka, Hiroaki, Yamamoto, Kazuhiro

We examine the effects of the linear and the cosmological redshift-space distortions on the power spectrum of cosmological objects on a light cone. We develop theoretical formulae for the power...

旋回噴流燃焼器を用いた強乱流予混合火炎の研究 (第1報, レーザトモグラフィー法による火炎構造の可視化) (1999)

山本, 和弘, YAMAMOTO, Kazuhiro, 阿知波, 朝士, ACHIHA, Tomoshi, 小沼, 義昭, ONUMA, Yoshiaki

By using a cyclone-jet combustor, we have investigated premixed flames in a highly turbulent flow over a wide range of turbulent properties, with μ'/SL exceeding 10 in a stationary jet flame. With...

The cosmological light-cone effect on the power spectrum of galaxies and quasars in wide-field redshift surveys (1999)

Yamamoto, Kazuhiro, Nishioka, Hiroaki, Suto, Yasushi

We examine observational consequences of the cosmological light-cone effect on the power spectrum of the distribution of galaxies and quasars from upcoming redshift surveys. First we derive an...

Two-point correlation functions of X-ray selected clusters of galaxies: theoretical predictions for flux-limited surveys (1999)

Suto, Yasushi, Yamamoto, Kazuhiro, Kitayama, Tetsu, Jing, Y. P.

We have developed a model to describe two-point correlation functions of clusters of galaxies in X-ray flux-limited surveys. Our model properly takes account of nonlinear gravitational evolution of...

Two-point correlation function of high-redshift objects on a light-cone: Effect of the linear redshift-space distortion (1999)

Nishioka, Hiroaki, Yamamoto, Kazuhiro

A theoretical formulation for the two-point correlation function on a light-cone is developed in the redshift space. On the basis of the previous work by Yamamoto & Suto (1999), in which a...

希薄燃焼に及ぼす水素添加の効果 (第2報, 管状火炎の特性と輸送過程に及ぼす回転強さの影響) (1999)

山本, 和弘, YAMAMOTO, Kazuhiro, 丸山, 昌幸, MARUYAMA, Masayuki, 小沼, 義昭, ONUMA, Yoshiaki

Lean combustion has the advantage of low pollutant emission levels, but its combustion rate is very low and the lean mixtures are difficult to ignite and form stable flames. To improve these...

Deciphering cosmological information from redshift surveys of high-z objects - the cosmological light-cone effect and redshift-space distortion - (1999)

Suto, Yasushi, Magira, Hiromitsu, Jing, Y. P., Matsubara, Takahiko, Yamamoto, Kazuhiro

The three-dimensional distribution of astronomical objects observed in redshift space significantly differs from the true distribution since the distance to each object cannot be determined by its...

Deciphering Cosmological Information from Redshift Surveys of High-z Objects - The Cosmological Light-Cone Effect and Redshift-Space Distortion (1999)

Yasushi Suto, Hiromitsu Magira, Y. P. Jing, Takahiko Matsubara, Kazuhiro Yamamoto

This paper consists of two topics which should play key roles in the theoretical interpretation of the future redshift surveys of high-redshift objects, the cosmological light-cone effect (x2) and...

Two-point correlation function of high-redshift objects: an explicit formulation on a light-cone hypersurface (1998)

Yamamoto, Kazuhiro, Suto, Yasushi

While all the cosmological observations are carried out on a light-cone, the null hypersurface of an observer at z=0, the clustering statistics has been properly defined only on the constant-time...

Magnetic Domain Structures and Dynamics of CoTaZr/Cr Multilayered Films. (1998)

Yamamoto, Kazuhiro, Matsuyama, Hideo, Hamakawa, Yoshihiro, Kitada, Masahiro

This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, data, mmc, mmc data materials and material types:, co-ta-zr...

回転流中における火炎の安定機構 (水素・空気混合気中に形成される管状火炎の燃焼特性) (1998)

山本, 和弘, YAMAMOTO, Kazuhiro, 浅井, 寛志, ASAI, Hiroshi, 石塚, 悟, ISHIZUKA, Satoru, ...

The effects of rotation on the stability and structure of tubular flames have been investigated for a lean hydrogen/air mixture, and mechanism of flame stability in a rotating flow has been...

Glucose-6-Phosphate Dehydrogenase in the Pentose Phosphate Pathway Is Localized in Vanadocytes of the Vanadium-Rich Ascidian, Ascidia sydneiensis samea (1998)

Taro Uyama, Kazuhiro Yamamoto, Kan Kanamori, Hitoshi Michibata

Ascidians are sessile marine animals known to accumulate high levels of vanadium selectively in vanadium-containing blood cells (vanadocytes). Almost all the vanadium accumulated in the vacuoles of...

Small-Scale Fluctuations in Cosmic X-ray Background : A Power Spectrum Approach (1998)

Yamamoto, Kazuhiro, Sugiyama, Naoshi

Equations to investigate fluctuations in cosmic X-ray background radiation due to point-like sources at high-redshift are formulated in a systematic way. The angular power spectrum of X-ray...

希薄燃焼に及ぼす水素添加の効果 (1998)

山本, 和弘, YAMAMOTO, Kazuhiro, 丸山, 昌幸, MARUYAMA, Masayuki, 小沼, 義昭, ONUMA, Yoshiaki

Lean combustion has the advantage of low pollutant emission levels, but its combustion rate is very low and the lean mixtures are difficult to ignite and form stable flames. To improve these...

Boltzmann approach to the large-angle cosmic X-ray background fluctuations (1998)

Miura, Yasuhiro, Yamamoto, Kazuhiro, Miyauchi, Kenta, Hosonuma, Masayasu

Large-angle fluctuations in the cosmic X-ray background are investigated by a new formalism with a simple model of the X-ray sources. Our method is formulated from the Boltzmann equation and a simple...

伸長・回転流れにおける圧力変化と火炎特性 (1997)

山本, 和弘, YAMAMOTO, Kazuhiro, 石塚, 悟, ISHIZUKA, Satoru

To investigate the pressure change and flame characteristics in a stretched, rotating flow, tubular flames of a lean hydrogen, methane, or propane-air mixture have been numerically simulated. Results...

Evolution of Small Scale Cosmological Baryon Perturbations and Matter Transfer Functions (1997)

Yamamoto, Kazuhiro, Sugiyama, Naoshi, Sato, Humitaka

The evolution of small scale cosmological perturbations is carefully re-examined. Through the interaction with photons via electrons, baryon perturbations show interesting behavior in some physical...

Cosmological Baryon Sound Waves Coupled with the Primeval Radiation (1997)

Yamamoto, Kazuhiro, Sugiyama, Naoshi, Sato, Humitaka

The fluid equations for the baryon-electron system in an expanding universe are derived from the Boltzmann equation. The effect of the Compton interaction is taken into account properly in order to...

軸対称流れ場に形成される管状火炎に及ぼす回転強さの影響 (1996)

山本, 和弘, YAMAMOTO, Kazuhiro, 石塚, 悟, ISHIZUKA, Satoru, 平野, 敏右, HIRANO, Toshisuke

Using an axisymmetric swirl-type burner with eight inlet slits, the effects of rotation on the structure and characteristics of tubular flames have been investigated for lean methane/air mixtures....

Observational Tests of One-Bubble Open Inflationary Cosmological Models (1995)

Yamamoto, Kazuhiro, Bunn, Emory F.

Motivated by recent studies of the one-bubble inflationary scenario, simple open cold dark matter models are tested for consistency with cosmological observations. The initial perturbation spectrum...

Self Excitation of the Tunneling Scalar Field in False Vacuum Decay (1995)

Hamazaki, Takashi, Sasaki, Misao, Tanaka, Takahiro, Yamamoto, Kazuhiro

A method to determine the quantum state of a scalar field after $O(4)$-symmetric bubble nucleation has been developed recently. The method has an advantage that it concisely gives us a clear picture...

Large Angle CMB Anisotropy in an Open Universe in the One-Bubble Inflationary Scenario (1995)

Yamamoto, Kazuhiro, Sasaki, Misao, Tanaka, Takahiro

We consider an alternative scenario of inflation which can account for a spatially open universe. It is similar to the old inflation in which the bubble nucleation occurs in the sea of false vacuum,...

Euclidian Vacuum Mode Functions for a Scalar Field on Open De Sitter Spacetime (1994)

Sasaki, Misao, Tanaka, Takahiro, Yamamoto, Kazuhiro

Motivated by recent studies of the one-bubble inflationary universe scenario that predicts a low density, negative curvature universe, we investigate the Euclidean vacuum mode functions of a scalar...

Particle Spectrum Created Through Bubble Nucleation (1994)

Yamamoto, Kazuhiro, Tanaka, Takahiro, Sasaki, Misao

Using the multi-dimensional wave function formalism, we investigate the quantum state of a scalar field inside a true vacuum bubble nucleated through false vacuum decay in flat spacetime. We...

Skewness of CMB Anisotropies in an Inflationary Isocurvature Baryon Model (1994)

Yamamoto, Kazuhiro, Sasaki, Misao

We investigate the cosmic variance of the skewness of the cosmic microwave background (CMB) anisotropies in an inflationary model which leads to the baryon isocurvature scenario for the cosmic...

Effects of heart rate on left ventricular filling dynamics: assessment from simultaneous recordings of pulsed Doppler transmitral flow velocity pattern and haemodynamic variables (1993)

Yamamoto, Kazuhiro, Masuyama, Tohru, Tanouchi, Jun, Doi, Yasuji, Kondo, Hiroya, Hori, Masatsugu, ...

Objective: The effects of heart rate on transmitral flow velocity pattern are still controversial. The aim of this study was to examine the relations between the changes in Doppler echocardiographic...

Knowledge spillovers, location of industry, and endogenous growth

Kyoko Hirose, Kazuhiro Yamamoto

A Grossman-Helpman-Romer-type endogenous-growth model is developed in this study. This model has two countries in which there are knowledge spillovers that are partially local. Owing to these...

Exclusive Expression of Transketolase in the Vanadocytes of the Vanadium-Rich Ascidian, Ascidia sydneiensis samea

Ueki, Tatsuya, 植木, 龍也, ウエキ, タツヤ, Uyama, Taro, Yamamoto, Kazuhiro, Kanamori, Kan, ...

Ascidians, especially those belonging to the Ascidiidae, are known to accumulate extremely high levels of vanadium in vanadocytes, one type of blood (coelomic) cell. Vanadium, which exists in the +5...

Nonlinear Evolution of Very Small Scale Cosmological Baryon Perturbations at Recombination.

Liu, Guo-Chin, Yamamoto, Kazuhiro, Sugiyama, Naoshi, Nishioka, Hiroaki

The evolution of baryon density perturbations on very small scales is investigated. In particular, the nonlinear growth induced by the radiation drag force from the shear velocity field on larger...

山本 一仁

山本,一仁, ヤマモト,カズヒト, Yamamoto,Kazuhiro

→研究テーマ,原著論文,英文,和文,著書,総説,国際シンポジウム学会発表,国内シンポジウム学会発表,公的研究費,主任研究者,分担研究者,委員会委員,...

Experimental Infection of Domestic Cats with Bartonella koehlerae and Comparison of Protein and DNA Profiles with Those of Other Bartonella Species Infecting Felines

Yamamoto, Kazuhiro, Chomel, Bruno B., Kasten, Rickie W., Hew, Carrie M., Weber, David K., Lee, Wilson I., ...

Bartonella koehlerae, a recently described feline Bartonella species, was isolated from two naturally infected cats in northern California. We experimentally infected domestic cats with B. koehlerae...

Streptomycin-Dependent Exhibition of Cytokine-Inducing Activity in Streptomycin-Dependent Mycobacterium tuberculosis Strain 18b

Fukasawa, Yutaka, Kawamura, Ikuo, Uchiyama, Ryosuke, Yamamoto, Kazuhiro, Kaku, Taijin, Tominaga, Takanari, ...

Peritoneal exudate cells of mice were stimulated with a streptomycin-dependent Mycobacterium tuberculosis strain, 18b. Gamma interferon production by natural killer cells depending on interleukin-12...

Sectorial sift, inverted U-shaped fertility dynamics, and growth

Ken Tabata, Kazuhiro Yamamoto

This paper constructs a small open two-sector overlapping-generations model with the subsistence level of consumption of agricultural goods and explains the following key stylized facts in the...

Experimental Infection of Domestic Cats with Bartonella koehlerae and Comparison of Protein and DNA Profiles with Those of Other Bartonella Species Infecting Felines

Yamamoto, Kazuhiro, Chomel, Bruno B., Kasten, Rickie W., Hew, Carrie M., Weber, David K., Lee, Wilson I., ...

Bartonella koehlerae, a recently described feline Bartonella species, was isolated from two naturally infected cats in northern California. We experimentally infected domestic cats with B. koehlerae...

Streptomycin-Dependent Exhibition of Cytokine-Inducing Activity in Streptomycin-Dependent Mycobacterium tuberculosis Strain 18b

Fukasawa, Yutaka, Kawamura, Ikuo, Uchiyama, Ryosuke, Yamamoto, Kazuhiro, Kaku, Taijin, Tominaga, Takanari, ...

Peritoneal exudate cells of mice were stimulated with a streptomycin-dependent Mycobacterium tuberculosis strain, 18b. Gamma interferon production by natural killer cells depending on interleukin-12...

Exclusive Expression of Transketolase in the Vanadocytes of the Vanadium-Rich Ascidian, Ascidia sydneiensis samea

Ueki, Tatsuya, 植木, 龍也, ウエキ, タツヤ, Uyama, Taro, Yamamoto, Kazuhiro, Kanamori, Kan, ...

Ascidians, especially those belonging to the Ascidiidae, are known to accumulate extremely high levels of vanadium in vanadocytes, one type of blood (coelomic) cell. Vanadium, which exists in the +5...

Nonlinear Evolution of Very Small Scale Cosmological Baryon Perturbations at Recombination.

Liu, Guo-Chin, Yamamoto, Kazuhiro, Sugiyama, Naoshi, Nishioka, Hiroaki

The evolution of baryon density perturbations on very small scales is investigated. In particular, the nonlinear growth induced by the radiation drag force from the shear velocity field on larger...

Variety expansion and fertility rate

Akiko Maruyama, Kazuhiro Yamamoto

To investigate how fertility rates interrelate with the modern economy, we construct a simple model in which variety expansion of consumption goods reduces fertility rates. In our model, variety...

Finance, Technology and Inequality in Economic Development

Ryo Horii, Ryoji Ohdoi, Kazuhiro Yamamoto

This paper presents an overlapping generations model with technology choice and credit market imperfections, in order to investigate a possible source of underdevelopment. The model shows that a...

Variety expansion and fertility rate

Akiko Maruyama, Kazuhiro Yamamoto

To investigate how fertility rates interrelate with the modern economy, we construct a simple model in which variety expansion of consumption goods reduces fertility rates. In our model, variety...

Variety expansion and fertility rates

Akiko Maruyama, Kazuhiro Yamamoto

To investigate how fertility rates interrelate with the modern economy, we construct a simple model in which variety expansion of consumption goods reduces fertility rates. In our model, variety...

Location of industry, market size, and imperfect international capital mobility

Yamamoto, Kazuhiro

This paper examines the impact of imperfect international capital mobility on an industrial location when increasing returns are present. When the international capital mobility is perfect,...

Technological progress, income inequality, and fertility

Yasuhiro Sato, Ken Tabata, Kazuhiro Yamamoto

Fertility, Income inequality, Technological progress, J1, O1,

Finance, Technology and Inequality in Economic Development

Ryo Horii, Ryoji Ohdoi, Kazuhiro Yamamoto

This paper develops an overlapping generations model with technology choice and imperfect credit market, in order to investigate a possible source of underdevelopment. Consistent with empirical...

Finance, Technology and Inequality in Economic Development

Ryo Horii, Ryoji Ohdoi, Kazuhiro Yamamoto

This paper presents an overlapping generations model with technology choice and credit market imperfections, in order to investigate a possible source of underdevelopment. The model shows that a...

Trade impacts on skill formation: welfare improvements accompanied by rises in inequality

Yasuhiro Sato, Kazuhiro Yamamoto

In this paper, we focus on the skill formation when considering the trade impacts on labor markets. Although workers are identical as unskilled labor, they differ in their productivity as skilled....

Trade and mergers in the presence of firm heterogeneity

Noriaki Matsushima, Yasuhiro Sato, Kazuhiro Yamamoto

We investigate the role of firm heterogeneity in considering profitability and desirability of mergers in the international economy. Analysis shows that higher trade costs make only crossborder...

Exit and Voice in a Marriage Market

Akiko Maruyama, Takashi Shimizu, Kazuhiro Yamamoto

In this paper, we present a model in which agents choose voice, exit, or stay options when their marital condition becomes bad. The "voice" option can be interpreted as a spouse's effort or...

Market Size and Entrepreneurship

Yasuhiro Sato, Takatoshi Tabuchi, Kazuhiro Yamamoto

In order to examine the impacts of market size on entrepreneurship, we estimate a monopolistic competition model that involves entrepreneurial decision by using data on Japanese prefectures. Our...

Exit and Voice in a Marriage Market

Akiko Maruyama, Takashi Shimizu, Kazuhiro Yamamoto

In this paper, we present a model in which agents choose voice, exit, or stay options when their marital condition becomes bad. The "voice" option can be interpreted as a spouse's effort or...

Horizontal mergers, firm heterogeneity, and R&D investments

Noriaki Matsushima, Yasuhiro Sato, Kazuhiro Yamamoto

We investigate the incentive and the welfare implications of a merger when heterogeneous oligopolists compete both in process R&D and on the product market. We examine how a merger affects the...