Collective 1/f1/f fluctuation by pseudo-Casimir-invariants

In this study, we propose a universal scenario explaining the $1/f$ fluctuation, including pink noises, in Hamiltonian dynamical systems with many degrees of freedom under long-range interaction. In the thermodynamic limit, the dynamics of such systems can be described by the Vlasov equation, which has an infinite number of Casimir invariants. In a finite system, they become pseudoinvariants, which yield quasistationary states. The dynamics then exhibit slow motion over them, up to the timescale where the pseudo-Casimir-invariants are effective. Such long-time correlation leads to $1/f$ fluctuations of collective variables, as is confirmed by direct numerical simulations. The universality of this collective $1/f$ fluctuation is demonstrated by taking a variety of Hamiltonians and changing the range of interaction and number of particles.Comment: 13 pages, 12 figure

Forecasting Long-Time Dynamics in Quantum Many-Body Systems by Dynamic Mode Decomposition

Numerically computing physical quantities of time-evolved states in quantum many-body systems is a challenging task in general. Here, we propose a method that utilizes reliable short-time data of physical quantities to accurately forecast long-time behavior. The method is based on the dynamic mode decomposition (DMD), which is commonly used in fluid dynamics. The effectiveness and applicability of the DMD in quantum many-body systems such as the Ising model in the transverse field at the critical point are studied, even when the input data exhibits complicated features such as multiple oscillatory components and a power-law decay with long-ranged quantum entanglements unlike fluid dynamics. It is demonstrated that the present method enables accurate forecasts at time as long as nearly an order of magnitude longer than that of the short-time training data. Effects of noise on the accuracy of the forecast are also investigated, because they are important especially when dealing with the experimental data. We find that a few percent of noise does not affect the prediction accuracy destructively.Comment: 18 pages, 24 figure

Bio-Mimetic Trajectory Generation Based on Human Arm Movements With a Nonholonomic Constraint

In this paper, a bio-mimetic trajectory of robots for manipulatinga nonholonomic car is generated with a time base generator (TBG).In order to reveal what kind of trajectories the robots should generatefor the given task, experiments with human subjects were performed. Ithas been shown that a human generates the trajectory with a single- ordouble-peaked velocity profile according to the geometrical conditions ofthe car. Then, bio-mimetic trajectories were generated by modeling the observedprimitive profiles with the TBG and also compared with the humantrajectories

知覚に基づく意思決定に確率情報と過去の意思決定が影響を及ぼす神経メカニズムの解明

学位の種別: 課程博士審査委員会委員 : （主査）東京大学教授 笠井 清登, 東京大学准教授 國松 聡, 東京大学准教授 山末 英典, 東京大学准教授 清水 潤, 東京大学講師 狩野 章太郎University of Tokyo(東京大学

Exercise hyperpnea and hypercapnic ventilatory responses in women

SummaryWe studied the relationship between exercise hyperpnea (i.e., ventilatory dynamics) at the onset of exercise and hypercapnic ventilatory response (HCVR), and their differences between the follicular (FP) and luteal (LP) phases of the menstrual cycle in six healthy females. HCVR was tested under three O2 conditions: hyperoxia (FiO2=1.0), normoxia (0.21), and hypoxia (0.12). HCVR was defined as the relationship between the end-tidal PCO2 and minute ventilation (V˙E) using the regression line of the CO2 slope and a mimetically apneic threshold of CO2. HCVR provocation and measurements were conducted using an inspired CO2 concentration of up to approximately 8mmHg higher than the end-tidal PCO2 level of basal isocapnic the end-tidal PCO2 at each menstrual both the slope and threshold in HCVR showed no statistically significant difference between LP and FP under any inspired FiO2 conditions. In the case of exercise hyperpnea during the onset of submaximal exercise, the mean response time (MRT) in V˙E dynamics showed no significant difference between LP and FP. Consequently, MRT in V˙E response was not related to the slope in HCVR. During steady-state exercise, even though the V˙E/V˙CO2 showed no significance between LP and FP, V˙E/V˙CO2 was significantly related to the slope in HCVR (r=0.59, P<0.05). Exercise ventilation (i.e., V˙E/V˙CO2) would partly be adjusted by the enhancement of the chemoreflex drive to CO2 only during the steady-state exercise

Diversity of cold-adapted ciliates from glacier snow and cryoconite in Arctic region

第2回極域科学シンポジウム/第33回極域生物シンポジウム 11月18日（金） 統計数理研究所 3階セミナー室

Creation of Curved Surface by Lathe Turning -Development of CAM system using original tool layout-

AbstractThe machining of 3D curved surfaces with an un-axisymmetric axis by lathe turning is proposed considering the best machinable tool layout. The best offset tool layout from the central axis of a spindle enables us to machine curved surfaces and to obtain a long tool life for hard material workpieces using a rotary tool. A dedicated NC program for the 3D surface using the original CAM system has been developed and applied to what. The machining results and the validity of our system are evaluated in this paper