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International Journal of Sediment Research 2022年第4期37卷 469-483页

作者： kazuyuki ota Takahiro Sato Ryosuke Arai Meteorology and Fluid Science Division Central Research Institute of Electric Power Industry

The current study proposes a novel framework for the numerical model for estimating the temporal scour considering unsteady sediment inflow and the sediment sorting process. The framework was applied to local scour upstream of a slit weir. The scour model is based on an ordinary nonlinear differential equation derived from sediment continuity and scour rate equations. A one-dimensional(1-D)Boussinesq-type model coupled with nonequilibrium sediment transport was incorporated in the scour model to consider unsteady sediment inflow. In addition, a mixing layer approach was incorporated to determine temporal variations in particle size in the scour hole. The proposed framework was validated using scour experiments conducted under conditions that include non-uniform sediment, live-bed scour,and unsteady flow rate. The simulation results showed satisfactory agreement with experimental results for the scour upstream of a slit weir. The proposed model appropriately explained the hysteresis process for flow unsteadiness, refilling process for live-bed scour, and armoring process for non-uniform sediments. In addition, the model framework proposed in the current study is applicable to local scour around other hydraulic structures(e.g., bridge piers) upon establishing the scour rate equation. Therefore, the current study provides a novel approach for modeling temporal scour that is required to consider unsteady sediment inflow and sediment sorting.

关键词： Local scour Temporal scour Mixing layer theory Slit weir Non-equilibrium bed load

Experimental investigation on cohesionless sandy bank failure resulting from water level rising

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International Journal of Sediment Research 2018年第1期33卷 47-56页

作者： Ryosuke Arai kazuyuki ota Takahiro Sato Yasushi Toyoda Fluid Dynamics Sector Central Research Institute of Electric Power Industry

In the last decade, sediment replenishment forming cohesionless sandy banks below dams has become an increasingly common practice in Japan to compensate for sediment deficits downstream. The erosion process of the placed cohesionless sediment is a combination of lateral toe-erosion and the following mass failure. To explore cohesionless bank failure mechanisms, a series of experiments was done in a soil tank using a compacted sandy soil mass exposed to an increasing water level. Two types of uniform sand(D50= 0.40 mm and 0.17 mm) and two bank heights（50 cm and 25 cm） were used under the condition of a constant bank slope of 75°. The three dimensional（3D） geometry of the bank after failure was measured using a handheld 3D scanner. The motion of bank failure was captured using the particle image velocimetry（PIV） technique, and the matric suction was measured by tensiometers. The compacted sandy soil was eroded by loss of matric suction accompanying the rise in water level which subsequently caused rotational slide and cantilever toppling failure due to destabilization of the bank. The effect of erosion protection resulting from the slumped blocks after these failures is discussed in the light of different failure mechanisms. Tensile strength is analyzed by inverse calculation of cantilever toppling failure events. The tensile strength had non-linear relation with degree of saturation and showed a *** findings of the study show that it is important to incorporate the non-linear relation of tensile strength into stability analysis of cantilever toppling failure and prediction of tension crack depth within unsaturated cohesionless banks.

关键词： Riverbank erosion Matric suction Cohesionless bank Tensile strength

X-ray spectroscopy of clusters of galaxies

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Research in Astronomy and Astrophysics 2012年第8期12卷 973-994页

作者： Naomi ota Department of Physics Nara Women’s University KitauoyanishimachiNaraNara 630-8506Japan

Clusters of galaxies are the most massive objects in the Universe and precise knowledge of their mass structure is important to understand the history of structure formation and constrain still unknown types of dark contents of the Universe. X-ray spectroscopy of galaxy clusters provides rich information about the physical state of hot intracluster gas and the underlying potential structure. In this paper, starting from the basic description of clusters under equilibrium conditions, we review properties of clusters revealed primarily through X-ray observations considering their thermal and dynamical evolutions. The future prospects of cluster studies using upcoming X-ray missions are also mentioned.

关键词： galaxies: clusters: general -- galaxies: intergalactic medium -- X-rays:galaxies: clusters -- cosmology: observations -- cosmology: dark matter

On the Live Coloration and Partial Mitochondrial DNA Sequences in the Topotypic Population of Goniurosaurus kuroiwae orientalis(Squamata: Eublepharidae), with Description of a New Subspecies from Tokashikijima Island, Ryukyu Archipelago, Japan

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Asian Herpetological Research 2017年第2期18卷 96-107页

作者： Masanao HONDA Hidetoshi ota Faculty of Life and Environmental Sciences University of Tsukuba Institute of Natural and Environmental Sciences University of Hyogo and Museum of Nature and Human Activities

Careful investigations of live coloration and other characters in the eublepharid gecko Goniurosaurus kuroiwae orientalis from Tonakijima Island, the type locality of the subspecies in the Central Ryukyus, Japan, revealed its slight but consistent external differences from the consubspecific Tokashikijima population, whose phylogenetically divergent status against the former had been strongly suggested in a previous molecular study. A new subspecies, Goniurosaurus kuroiwae sengokui subsp. nov., is thus described for the Tokashikijima population. In life, Goniurosaurus k. sengokui subsp. nov. can be discriminated from G. k. orientalis in showing tint of reddish or pinkish, instead of yellowish, coloration in dorsal body pattern, and also usually darker and more or less reddish, instead of yellowish or grayish, iris in both adults and juveniles. Recalculation of sequence data at hand with relevant Gen Bank data confirmed substantial sequence divergences of G. k. sengokui from all other congeneric taxa of the Ryukyus described so far.

关键词： Eublepharidae Goniurosaurus morphology taxonomy Ryukyu Archipelago

Laser Manipulation of Micro Untransmissive Particles in Water

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Journal of Thermal Science 2009年第1期18卷 85-90页

作者： Masahiro ota Makoto SHIMODA Yuuki SUSAI Division of Mechanical Engineering Tokyo Metropolitan University

The laser trapping of untransmissive particles are discussed in this paper. Photon can generate the momentum tothe untransmissive particle by diffraction and reflection on the surface of the particles. We tried laser trapping ofuntransmissive particles using an attractive force caused by the diffraction and radiation force caused by *** laser trapping system includes CW YAG laser, which has 1.064 μm in wave length and an optical *** motions of particles were monitored by a CCD camera on the top of the microscope and recordedby PC connected to the CCD camera.

关键词： Laser manipulation Laser trapping Optical tweezers Micro manipulation Micro sphere

Energy-efficient buffer and service rate allocation in manufacturing systems using hybrid machine learning and evolutionary algorithms

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Advances in Manufacturing 2024年第2期12卷 227-251页

作者： Si-Xiao Gao Hui Liu Jun ota Key Laboratory of Traffic Safety on Track of Ministry of Education Institute of Artificial Intelligence and Robotics(IAIR)School of Traffic and Transportation EngineeringCentral South UniversityChangsha410075People’s Republic of China Research into Artifacts Center for Engineering School of EngineeringThe University of TokyoTokyoJapan

Currently,simultaneous buffer and service rate allocation is a topic of interest in the optimization of manufacturing *** allocation problems have been solved previously to satisfy economic requirements;however,owing to the progress of green manufacturing,energy conservation and environmental protection have become increasingly ***,an energy-efficient approach is developed to maximize the throughput and minimize the energy consumption of manufacturing systems,subject to the total buffer capacity,total service rate,and predefined energy *** energy-efficient approach integrates the simulated annealing-non-dominated sorting genetic algorithm-II with the honey badger algorithm-histogram-based gradient boosting regression *** former algorithm searches for Pareto-optimal solutions of sufficient *** latter algorithm builds prediction models to rapidly calculate the throughput,energy consumption,and energy *** examples show that the proposed hybrid approach can achieve a better solution quality compared with previously reported ***,the prediction models can rapidly evaluate manufacturing systems with sufficient *** study benefits the multi-objective optimization of green manufacturing systems.

关键词： Energy-efficient allocation Multi-objective optimization Energy efficiency Energy consumption Machine learning

Manipulation of Micro Solid Particles and Induced Flows in Water by Laser Irradiation

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Journal of Thermal Science 2007年第2期16卷 176-180页

作者： Masahiro ota Hiroshi OKANO Makoto YOSHIDA Division of Mechanical Engineering Tokyo Metropolitan University1Minami-osawaHachi-ojiTokyo 192-0397Japan

Q-switch for pulsing laser beam and Galvano scanner for rapid scanning laser beam were adapted to manipulate micro solid particles in a water droplet. The trapping of fine particles at micron-sized diameters by a YAG laser system, induced flows, and the induced motion of the particles by laser beam irradiations are discussed. Particle rotations are observed by using anisotropic micro objects, and moreover the rotational rate with clockwise direction is 22 r/min. The fragments of a cover glass were mixed in a water droplet, and their size and shape are uneven. The rotation of that non-spheres without scanning by the Galvano scanner is also observed in water.

关键词： Laser trapping non-sphere particle optical radiation pressure laser scanning laser drive rotation

A Broad Learning-Driven Network Traffic Analysis System Based on Fog Computing Paradigm

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China Communications 2020年第2期17卷 1-13页

作者： Xiting Peng Kaoru ota Mianxiong Dong Department of Information and Electronic Engineering Muroran Institute of Technology

The development of communication technologies which support traffic-intensive applications presents new challenges in designing a real-time traffic analysis architecture and an accurate method that suitable for a wide variety of traffic *** traffic analysis methods are executed on the cloud,which needs to upload the traffic *** computing is a more promising way to save bandwidth resources by offloading these tasks to the fog ***,traffic analysis models based on traditional machine learning need to retrain all traffic data when updating the trained model,which are not suitable for fog computing due to the poor computing *** this study,we design a novel fog computing based traffic analysis system using broad *** one thing,fog computing can provide a distributed architecture for saving the bandwidth *** another,we use the broad learning to incrementally train the traffic data,which is more suitable for fog computing because it can support incremental updates of models without retraining all *** implement our system on the Raspberry Pi,and experimental results show that we have a 98%probability to accurately identify these traffic ***,our method has a faster training speed compared with Convolutional Neural Network(CNN).

关键词： traffic analysis fog computing broad learning radio access networks

Treatment of coronary in-stent restenosis： a systematic review

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Journal of Geriatric Cardiology 2018年第2期15卷 173-184页

作者： Leos Pleva Pavel Kukla ota Hlinomaz Department of Cardiovascular Diseases University Hospital Ostrava Czech Republic Department of Cardioangiology St. Anne's University Hospital and Faculty of Medicine Masaryk University Brno CZ Czech Republic International Clinical Research Center St. Anne's University Hospital Brno CZ Czech Republic

Coronary stem implantation has significantly improved percutaneous coronary intervention and enabled the management of early complications of plain balloon angioplasty. However, a new complication has accompanied these improvements： in-stent restenosis （ISR） arising from neointimal hyperplasia. ISR after coronary angioplasty is currently one of the main limitations of this method, leading to the recurrence of exertional angina pectoris or acute coronary syndromes. The clinical incidence of ISR after bare-metal stent （BMS） implantation is approximately 20%35%. The use of drug-eluting stents （DES） has led to a further decrease in the occurrence of ISR to 5%-10%. Evidence resulting from controlled clinical studies suggests that DES and drug-eluting balloon catheters （DEB） provide the best clinical and angiographic results in the treatment of ISR. We undertook a systematic review of the pathophysiology, diagnostics and treatment options for BMS- and DES-ISR. We discuss recent randomised studies, comparing different DES or DEB used for BMS or DES-ISR treatment, as well as the use of new biovascular scafolds and the topic of scafold restenosis.

关键词： Drug-eluting balloon Drug-eluting stent In-stent restenosis

A Real Plug-and-Play Fog: Implementation of Service Placement in Wireless Multimedia Networks

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China Communications 2019年第10期16卷 191-201页

作者： Jianwen Xu Kaoru ota Mianxiong Dong Department of Sciences and Informatics Muroran Institute of Technology

Initially as an extension of cloud computing, fog computing has been inspiring new ideas about moving computing tasks to the edge of networks. In fog, we often repeat the procedure of placing services because of the geographical distribution of mobile users. We may not expect a fixed demand and supply relationship between users and service providers since users always prefer nearby service with less time delay and transmission consumption. That is, a plug-and-play service mode is what we need in fog. In this paper, we put forward a dynamic placement strategy for fog service to guarantee the normal service provision and optimize the Quality of Service (QoS). The simulation results show that our strategy can achieve better performance under metrics including energy consumption and end-to-end latency. Moreover, we design a real Plug-and-Play Fog (PnPF) based on Raspberry Pi and OpenWrt to provide fog services for wireless multimedia networks.

关键词： wireless multimedia networks fog computing service placement quality of service