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The deterministic condition for the ground reaction force acting point on the combined knee valgus and tibial internal rotation moments in early phase of cutting maneuvers in female athletes

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Journal of Sport and Health Science 2024年第3期13卷 376-386页

作者： Issei Ogasawara Ken ohta Gajanan S.Revankar Shoji Konda Yohei Shimokochi Hideyuki Koga Ken Nakata Department of Health and Sport Sciences Graduate School of MedicineOsaka UniversityToyonaka 560-0043Japan Sports Sensing Co. LTD.Fukuoka 815-0035Japan Department of Neurology Graduate School of MedicineOsaka UniversitySuita 565-0871Japan Department of Health and Sport Management Osaka University of Health and Sport SciencesSennan-gun 590-0496Japan Department of Joint Surgery and Sports Medicine Graduate School of Medical and Dental SciencesTokyo Medical and Dental UniversityBunkyo-ku 113-8519Japan

Background:Combined knee valgus and tibial internal rotation(VL+IR)moments have been shown to stress the anterior cruciate ligament(ACL)in several in vitro cadaveric *** utilize this knowledge for non-contact ACL injury prevention in sports,it is necessary to elucidate how the ground reaction force(GRF)acting point(center of pressure(CoP))in the stance foot produces combined knee VL+IR moments in risky maneuvers,such as ***,the effects of the GRF acting point on the development of the combined knee VL+IR moment in cutting are still ***:We first established the deterministic mechanical condition that the CoP position relative to the tibial rotational axis differentiates the GRF vector’s directional probability for developing the combined knee VL+IR moment,and theoretically predicted that when the CoP is posterior to the tibial rotational axis,the GRF vector is more likely to produce the combined knee VL+IR moment than when the CoP is anterior to the tibial rotational ***,we tested a stochastic aspect of our theory in a lab-controlled in vivo *** females performed 60˚cutting under forefoot/rearfoot strike conditions(10 trials each).The positions of lower limb markers and GRF data were measured,and the knee moment due to GRF vector was *** trials were divided into anterior-and posterior-CoP groups depending on the CoP position relative to the tibial rotational axis at each 10 ms interval from 0 to 100 ms after foot strike,and the occurrence rate of the combined knee VL+IR moment was compared between trial ***:The posterior-CoP group showed significantly higher occurrence rates of the combined knee VL+IR moment(maximum of 82.8%)at every time point than those of the anterior-CoP trials,as theoretically predicted by the deterministic mechanical ***:The rearfoot strikes inducing the posterior CoP should be avoided to reduce the risk of non-contact ACL injury associated with the com

关键词： Center of pressure Deterministic condition Foot strike pattern Injury mechanism Moment of ground reaction force

AI技术的意图与审美问题:再论人工智能诗歌

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上海交通大学学报（哲学社会科学版） 2024年第2期32卷 84-95页

作者：程羽黑上海交通大学人文艺术研究院上海200240

现阶段的AI诗歌是“无意图”的诗歌,AI诗歌算法的完善能避免无效诗句的出现。研发者不必追求强人工智能作诗,而应在现有的弱人工智能框架下,通过文体和风格的专门训练提升AI诗歌的水准。通过比较诗歌的人文性和科学性可知:两者并不是互... 详细信息

现阶段的AI诗歌是“无意图”的诗歌,AI诗歌算法的完善能避免无效诗句的出现。研发者不必追求强人工智能作诗,而应在现有的弱人工智能框架下,通过文体和风格的专门训练提升AI诗歌的水准。通过比较诗歌的人文性和科学性可知:两者并不是互斥的,而是相容的,最终殊途同归。人类不必担忧AI诗歌的未来,也不应把重点放在AI诗歌的拟真性上,而应扬长避短,通过AI的量化优势探索诗歌的可能性。

关键词： AI 诗歌意图风格算法

An Improved Coupled Level Set and Continuous Moment-of-Fluid Method for Simulating Multiphase Flows with Phase Change

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1034-1069页

作者： Zhouteng Ye Cody Estebe Yang Liu Mehdi Vahab Zeyu Huang Mark Sussman Alireza Moradikazerouni Kourosh Shoele Yongsheng Lian Mitsuhiro ohta M.Yousuff Hussaini ZJUI Institute Zhejiang UniversityHaining 314400ZhejiangChina Department of Mathematics Florida State UniversityTallahasseeUSA Department of Mechanical Engineering Florida State UniversityTallahasseeUSA Mechanical and Aerospace Engineering Mathworks NatickMAUSA School of Aerospace Engineering Tsinghua UniversityBeijing 100084China Department of Mechanical Engineering University of LouisvilleLouisvilleUSA Department of Mechanical Science Tokushima UniversityTokushimaJapan

An improved algorithm for computing multiphase flows is presented in which the multimaterial Moment-of-Fluid(MOF)algorithm for multiphase flows,initially described by Li et al.(2015),is enhanced addressing existing MOF difficulties in computing solutions to problems in which surface tension forces are crucial for understanding salient flow *** Continuous MOF(CMOF)method is motivated in this *** CMOF reconstruction method inherently removes the"checkerboard instability"that persists when using the MOF method on surface tension driven multiphase(multimaterial)*** CMOF reconstruction algorithm is accelerated by coupling the CMOF method to the level set method and coupling the CMOF method to a decision tree machine learning(ML)*** flow examples are shown in the two-dimensional(2D),three-dimensional(3D)axisymmetric"RZ",and 3D coordinate *** include two material and three material multiphase flows:bubble formation,the impingement of a liquid jet on a gas bubble in a cryogenic fuel tank,freezing,and liquid lens dynamics.

关键词： Moment-of-Fluid(MOF) Surface tension Two phase flow Phase change Deforming boundaries with change(s)in topology Two-dimensional(2D) Three-dimensional(3D)axisymmetric 3D

How to model the contractive behavior of soil in a heating test

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Underground Space 2016年第1期1卷 30-43页

作者： Feng Zhang yuhei Kurimoto Nagoya Institute of Technology Japan Graduate School of Engineering Nagoya Institute of TechnologyJapan

In this paper,the thermodynamic behavior of soil was observed in well-known heating tests via a simulation,which included THMcoupled finite element analysis as the boundary value problem(BVP).The primary purpose of the paper was to identify the necessity to model a phenomenon called‘the volumetric contraction of soft clay due to heating’by introducing some extra parameters in the thermoelastoplastic model in which the THM analyses were *** on the simulation,it was determined that the heating test is only a BVP,and the phenomenon is simply an average behavior of the BVP,not an inherent property of *** on the universal rule that any material will expand when heated,it is not necessary to introduce an extra parameter into a properly organized thermo-elastoplastic model to describe the *** results may provide a useful insight for researchers who are interested in modeling the thermodynamic behavior of soils.

关键词： THM analysis Thermo-elasto-viscoplastic model Heating test Normal and over-consolidated clay

Simultaneous Oxidization of NO_x and SO_2 by a New Non-thermal Plasma Reactor Enhanced by Catalyst and Additive

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Plasma Science and Technology 2008年第1期10卷 53-56页

作者： Heejoon KIM 韩军 yuhei SAKAGUCHI Wataru MINAMI Department of Ecological Engineering Toyohashi University of Technology Hnbei Province Key Laboratory of Coal Conversion and New Carbon Materials Wuhan University of Science and Technology

The non-thermal plasma as one of the most promising technologies for removing NOx and SO2 has attrm^ted much attention. In this study, a new plasma reactor combined with catalyst and additive was developed to effectively oxidize and remove NOx and SO2 in the flue gas. The experimental results showed that TiO2 could improve the oxidation efficiency of SO2 in the case of applying plasma while having a negative effect on the oxidation process of NO and NOx. With the addition of NH3, the oxidation rates of NOx, NO and SO2 were slightly increased. However, the effect of adding NH3 on NOx oxidation was negative when the temperature was above 200℃.

关键词： additive catalyst NOx SO2 oxidation rate plasma

Unsteady Behavior and Control of Vortices in Centrifugal Compressor

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Journal of Thermal Science 2014年第5期23卷 401-411页

作者： Yutaka ohta Nobumichi Fujisawa Department of Applied Mechanics and Aerospace Engineering Waseda University3-4-1OkuboShinjukuTokyo169-8555Japan Graduate School of Fundamental Science and Engineering Waseda University3-4-1OkuboShinjukuTokyo169-8555Japan

Two examples of the use of vortex control to reduce noise and enhance the stable operating range of a centrifugal compressor are presented in this *** the case of high-flow operation of a centrifugal compressor with a vaned diffuser,a discrete frequency noise induced by interaction between the impeller-discharge flow and the diffuser vane,which appears most notably in the power spectra of the radiated noise,can be reduced using a tapered diffuser vane(TDV) without affecting the performance of the *** longitudinal vortices produced by leakage flow passing through the tapered portion of the diffuser vane induce secondary flow in the direction of the blade surface and prevent flow separation from the leading edge of the *** use of a TDV can effectively reduce both the discrete frequency noise generated by the interaction between the impeller-discharge flow and the diffuser surface and the broadband turbulent noise *** the case of low-flow operation,a leading-edge vortex(LEV) that forms on the shroud side of the suction surface near the leading edge of the diffuser increases significantly in size and blocks flow in the diffuser *** formation of an LEV may adversely affect the performance of the compressor and may cause the diffuser to *** a one-side tapered diffuser vane to suppress the evolution of an LEV,the stable operating range of the compressor can be increased by more than 12 percent,and the pressure-rise characteristics of the compressor can be *** results of a supplementary examination of the structure and unsteady behavior of LEVs,conducted by means of detailed numerical simulations,are also presented.

关键词： centrifugal compressor vortex control interaction tone noise noise reduction CFD DES analysis stability enhancement leading-edge vortex.

Coexisting State of Surge and Rotating Stall in a Two-Stage Axial Flow Com-pressor using a Double-Phase-Locked Averaging Technique

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Journal of Thermal Science 2017年第1期26卷 38-46页

作者： Yuu SAKATA Yutaka ohta Graduate school of Fundamental Science and Engineering Waseda University 3-4-10kuboShinjuku Tokyo 169-8555 Japan. Department of Applied Mechanics and Aerospace Engineering Waseda University 3-4-10kubo Shinjuku Tokyo169-8555 Japan.

The interaction between surge and rotating stall in an axial flow compressor was investigated from the viewpoint of an unsteady inner flow structure. The aim of this study was to identify the key factor that determines the switching phenomenon of a surge cycle. The main feature of the tested compressor is a shock tube connected in series to the compressor outlet through a diaphragm, slits, and a concentric duplex pipe: this system allows surge and rotating stall to be generated by connecting the shock tube with the compressor, or enables the compression plane wave injection. The unsteady characteristics and the internal flow velocity fluctuations were measured in detail, and the stall cell structure was averaged and visualized along the movement of the operation point under a coexisting state of surge. A coefficient of the cell scale fluctuation was calculated using the result of the averaging, and it confirmed that the processes of inner flow structure change differed from each other according to the next cycle of the surge. The result suggests that the key factor that determines the next cycle is the transformation of the internal flow structure, particularly between the stall cell and the entire circumferential stall, in both the recovering and stalling processes.

关键词： Axial flow compressor, Rotating stall, Surge, Double-phase-locked measurement, Compression wave.

Effect of hydraulic retention time on the hydrogen yield and population of Clostridium in hydrogen fermentation of glucose

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Journal of Environmental Sciences 2009年第4期21卷 424-428页

作者： CHU Chunfeng EBIE Yoshitaka INAMORI yuhei KONG Hainan School of Environmental Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China National Institute for Environmental Studies Tsukuba 305-8506 Japan Faculty of Symbiotic Systems Science Fukushima University Fukushima 960-1296 Japan

The conversion of glucose to hydrogen was evaluated using continuous stirred tank reactor at pH 5.5 with various hydraulic retention times （HRT） at 30℃. Furthermore, the population dynamics of hydrogen-producing bacteria was surveyed by fluorescence in-situ hybridization using probe Clost IV targeting the genus Clostridium based on 16S rRNA. It was clear that positive correlation was observed between the cells quantified with probe Clost IV and hydrogen yield of the respective sludge. The numbers of hydrogen- producing bacteria were decreased gradually with increasing HRT, were 9.2 × 10^8, 8.2 × 10^8, 2.8 × 10^8, and 6.2 × 10^7 cell/mL at HRT 6, 8, 12, and 14 h, respectively. The hydrogen yield was 1.4-1.5 mol H2/mol glucose at the optimum HRT range 6-8 h. It is considered that the percentage of the hydrogen-producing bacteria to total bacteria is useful parameter for evaluation of hydrogen production process.

关键词： bio-hydrogen fluorescence in-situ hybridization genus Clostridium

The thermal conductivity of the Earth's core and implications for its thermal and compositional evolution

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National Science Review 2021年第4期8卷 18-20页

作者： Kenji ohta Kei Hirose Department of Earth and Planetary Sciences Tokyo Institute of Technology Earth-Life Science Institute Tokyo Institute of Technology Department of Earth and Planetary Science The University of Tokyo

The thermal conductivity of iron alloys is a key to understanding the mechanism of convection in the Earth’s liquid core and its thermal history. The Earth’s magnetic field is formed by a dynamo action that requires... 详细信息

关键词： ELECTRICAL-RESISTIVITY HIGH-PRESSURE IRON ALLOYS SI NI