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CAAI Transactions on Intelligence Technology 2022年第4期7卷 549-560页

作者： Seiji saito Shouta Oka Ribun Onodera Department of Electronics and Information Science Polytechnic UniversityKodairaTokyoJapan

This paper presents a hysteresis mathematical model of a shape memory alloy(SMA)actuator for feedforward hysteresis compensator.The hysteresis model represents the relation between temperature,stress,and electric resistance.Firstly,based on the laws of thermodynamics,the hysteresis model of the SMA actuator is built.Secondly,the inverse of the hysteresis model is obtained to produce a compensator for non‐linear characteristics such as hysteresis and saturation.Thirdly,the parameters of the hysteresis model are obtained from each experiment under constant load and constant temperature,and the model validity is confirmed by comparing experimentally obtained results.Finally,the inverse model is applied to a part of feedforward hysteresis compensator.In order to verify the effectiveness of the proposed model as hysteresis compensator,an electrical resistance control using feedback-feedforward control was conducted by numerical simulation.The simulation results indicate advantages of the proposed mathematical model in hysteresis compensation of SMA actuator,and demonstrate that the model is capable of handling load fluctuation.

关键词： hysteresis inverse thermodynamics

Dynamic pressure change in a rotating, laterally oscillating cylindrical container

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Journal of Ocean Engineering and Science 2018年第2期3卷 91-95页

作者： Yusuke saito Tatsuo Sawada Department of Mechanical Engineering Keio University3-14-1 HiyoshiKohoku-kuYokohama 223-8522Japan

We examined wave phenomena pertinent to water in a rotating,laterally oscillating cylindrical container.In particular,we measured the time-dependent dynamic water pressure and pressure change by fast Fourier transform analysis.The swirling of water in the container had three frequency components;the frequency responses of each frequency component are reported herein.When swirling occurs in a rotating cylindrical container,it was found that the wave rotating in the same direction as the rotation of the cylindrical container and the wave rotating in the opposite direction to the cylindrical container exist at the same time.The swirling direction was determined by the relationship of these magnitude.

关键词： Sloshing Dynamic pressure Cylindrical container Rotation Oscillation Swirling

Electromechanically reconfigurable plasmonic photodetector with a distinct shift in resonant wavelength

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Microsystems & Nanoengineering 2023年第2期9卷 219-226页

作者： Masaaki Oshita Shiro saito Tetsuo Kan Graduate School of Informatics and Engineering The University of Electro-Communications1-5-1ChofugaokaChofu-cityTokyo 182-8585Japan IMRA JAPAN CO. LTD2-36Hachiken-choKariyaAichi 448-8650Japan

Plasmonic photodetectors have received increasing attention because their detection properties can be designed by tailoring their metal structures on surfaces without using any additional components.Reconfiguration of the plasmonic resonant state in a photodetector is relevant for various applications,including investigating in situ adaptive detection property changes,depending on the situation,and performing single-pixel spectroscopy in geometrically limited regions.However,the spectral responsivity change with conventional reconfiguration methods is relatively small.Here,we propose a plasmonic photodetector that reconfigures its spectral responsivity with electromechanical deformation instead of bias tuning.The photodetector consists of a gold plasmonic grating formed on an n-type silicon cantilever,and the spectral responsivity is reconfigured by electromechanically scanning at an incident angle to the grating on the cantilever.The photodetector exhibits peak shifts in spectral responsivity in a wavelength range from 1250 to 1310 nm after electromechanical reconfiguration.Finally,for potential future applications,we demonstrate near-infrared spectroscopy using the photodetector.This photodetector has the potential to be adopted as a near-infrared spectrometer in industrial silicon imaging systems because its structure enables subbandgap photodetection on silicon by a Schottky junction.

关键词： tuning reconfigurable resonant

Efficacy and sustainability of dialectical behaviour therapy for inpatient adolescents:a follow-up study

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General Psychiatry 2021年第4期34卷 51-59页

作者： Alison Ann Tebbett-Mock Madeline McGee Ema saito Psychiatry Zucker Hillside HospitalNorthwell HealthGlen OaksNew YorkUSA

Background Dialectical behaviour therapy(DBT)is an evidence-based treatment for adolescents targeting suicidal and non-suicidal self-injurious behaviours.Research supports DBT’s efficacy in inpatient settings,but implementation and sustainability are understudied.Aims This study is a follow-up of a previous study by Tebbett-Mock et al and examines the efficacy and sustainability of an adolescent DBT inpatient unit within a psychiatric hospital in the Northeast.We hypothesised that adolescents who received DBT in our follow-up group(DBT Group 2)would not have statistical difference(ie,greater or fewer)of the following compared with the first group of patients who received DBT on the unit the year prior(DBT Group 1)and would have significantly fewer of the following compared with the treatment as usual(TAU)group:(1)constant observation hours for suicidal ideation,self-injury and aggression;(2)incidents of suicide attempts,self-injury and aggression;(3)restraints;(4)seclusions;(5)days hospitalised;(6)times readmitted to the unit within 30 days of discharge.Methods We conducted a retrospective chart review for adolescents receiving inpatient DBT(DBT Group 1,n=425;DBT Group 2,n=393)and a historical control group(TAU,n=376).The χ^(2) tests and one-way analysis of variance were conducted as preliminary analyses to examine group differences on diagnosis,gender and age.Kruskal-Wallis H tests were conducted to examine group differences on outcomes.Mann-Whitney U tests were used as post hoc analyses.Results Patients in DBT Group 2 were comparable to DBT Group 1 for the number of constant observation hours for self-injury(U=83432.50,p=0.901),restraints(U=82109,p=0.171)and days hospitalised(U=83438.5,p=0.956).Patients in DBT Group 2 had a significantly greater number of incidents of suicide attempts compared with DBT Group 1(U=82662.5,p=0.037)and of self-injury compared with patients in DBT Group 1(U=71724.5,p<0.001)and TAU(U=65649.0,p<0.001).Conclusions Results provide support for adolescent inpatient DBT compared with TAU a

关键词： behaviour admitted diagnosis

Increased utilization and mass activity of PtRu on reduced graphene oxide by heat treatment of its aerogel followed by composite with nanomaterials

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Carbon Resources Conversion 2023年第3期6卷 205-214页

作者： Kenta Dejima Hirokazu Ishitobi He Gao Mai saito Nobuyoshi Nakagawa Graduate School of Science and Technology Gunma University1-5-1Tenjin-choKiryuGunma 376-8515Japan Division of Environmental Engineering Science Gunma University1-5-1Tenjin-choKiryuGunma 376-8515Japan Faculty of Science and Technology Gunma University1-5-1Tenjin-choKiryuGunma 376-8515Japan

The method to increase PtRu utilization and its catalytic activity of PtRu nanoparticles supported on reduced graphene oxide(RGO)by avoiding its restacking was proposed with the aim of developing an active catalyst for a direct methanol fuel cell.The heat treatment at 200◦C of the GO aerogel(GOA)prepared by freeze drying of GO ice was introduced to weaken the attractive force of the hydrogen bonding between the GO sheets followed by the composite with the nanoparticles,i.e.,ketjenblack(KB),TiO_(2)and Ti_(4)O_(7),at different weight ratios.The catalyst supported on the heat-treated GOA(RGOA),PtRu/RGOA,improved the PtRu utilization to some extent and also increased the ECSA and mass activity compared to that of PtRu/RGO.RGOA had fewer oxygen functional groups,especially the epoxy groups.Due to the treatment and composite,the PtRu utilization was increased from 66.5%for PtRu/RGO to 128.6%for PtRu/RGOA+Ti_(4)O_(7)(4:1)and the mass activity was improved from 50.7 A/g-PtRu for PtRu/RGO to 130.5 A/g-PtRu for PtRu/RGOA+Ti_(4)O_(7)(1:1).The Ti_(4)O_(7)nanoparticles showed the best catalytic performance for the composite suggesting that the strong interaction between Ti_(4)O_(7)and the Pt nanoparticles was effective due to its high electronic conductivity.

关键词： Reduced graphene oxide Restacking Catalyst utilization Mass activity Composite catalyst Methanol oxidation Ti4O7

Natural Convection Melting in a Rectangular Heat Storage Tank of Carbon Nanotube Dispersed Latent Heat Storage Material

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Journal of Thermal Science 2024年第3期33卷 847-855页

作者： Shin-ichi MORITA Tomoya saito Kazunori TAKAI Yasutaka HAYAMIZU Naoto HARUKI Division of Mechanical and Electrical Engineering Kitami Institute of Technology165 Koen-choKitami-shiHokkaido090-8507Japan National Institute of Technology Yonago College4448 Hikona-cyoYonago-shiTottori683-8502Japan Okayama Prefectural University 111 KubokiSoja-shiOkayama719-1197Japan

A dispersion system fluid can convect even if the dispersoid is a solid phase.Therefore,heat exchange performance can be improved while maintaining fluidity using a material with high thermal conductivity as the dispersoid.This study presents the melting performance evaluation results of a latent heat storage material with a carbon nanotube(CNT)dispersion system with high thermal conductivity,which enhances the thermal conductivity of the latent heat storage material and does not limit free convection.Increasing the thermal conductivity and enhancing the melting convection of the heat storage material result in increased latent heat storage speed.In this study,the thermal conductivity of the latent heat storage material was successfully increased by dispersing CNTs in the material.When 0.1%(in mass)of multi-wall CNT(MWCNT)was dispersed in a paraffin-based latent heat storage material,the shear stress increased by 1.5 times at a shear rate of 500 s^(-1),while taking into account the potential effects of convective inhibition.Therefore,a latent heat storage experiment was conducted in a rectangular heat storage tank using the CNT dispersion composition ratio as a parameter.A rectangular vessel with a heated vertical surface was used for the latent heat storage experiment.The melting speed was determined by comparing the amount of latent heat stored in a CNT-dispersed latent heat storage material and a single-phase latent heat storage material sample.The experimental results show that the time required for the latent heat storage material to completely melt in the heat storage tank was the shortest for the single-phase latent heat storage material sample.However,the fastest melting progress was observed for the sample with 0.02%(in mass)MWCNT content in the melting rate range of up to approximately 40%in the tank.The results indicate that this phenomenon is caused by the difference in the melting rates in the upper part of the tank.The generated data are useful for determining the shape and heat transfer surface arr

关键词： latent heat storage phase change carbon nano tube free convection heat transfer

Risk prediction of common bile duct stone recurrence based on new common bile duct morphological subtypes

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World Journal of Gastrointestinal Surgery 2022年第8期14卷 874-876页

作者： Hirokazu saito Shuji Tada Department of Gastroenterology Kumamoto City HospitalKumamoto 862-8505Japan

Stones in the common bile duct(CBD) are reported worldwide, and this condition is majorly managed through endoscopic retrograde cholangiopancreatography(ERCP). CBD stone recurrence is an important issue after endoscopic stone removal. Therefore, it is essential to identify its risk factors to determine the necessity of regular follow-up in patients who underwent endoscopic removal of CBD stones. The authors identified that the S and polyline morphological subtypes of CBD were associated with increased stone recurrence. New morphological subtypes of CBD presented by the authors can be important risk predictors of recurrence after endoscopic stone removal. Furthermore, the new morphological subtypes of CBD may predict the risk of residual CBD stones or technical difficulty in CBD stone removal. Further studies with a large sample size and longer follow-up durations are warranted to examine the usefulness of the newly identified morphological subtypes of CBD in predicting the outcomes of ERCP for CBD stone removal.

关键词： Endoscopic retrograde cholangiopancreatography Common bile duct stone Stone removal Recurrence Common bile duct morphology Risk prediction

Characterization of Malalignment between Atrial and Ventricular Septa in Overriding/Straddling Tricuspid and Mitral Valves

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Congenital Heart Disease 2021年第1期16卷 1-16页

作者： Mika saito Dragulescu Andreea Shi-Joon Yoo The Labatt Family Heart Centre The Hospital for Sick ChildrenUniversity of TorontoTorontoCanada Division of Cardiology Department of PaediatricsThe Hospital for Sick ChildrenUniversity of TorontoTorontoCanada Department of Diagnostic Imaging The Hospital for Sick ChildrenUniversity of TorontoTorontoCanada

Objective:Overriding/straddling of an atrioventricular valve is a consequence of atrial-ventricular septal malalignment.We sought to characterize the malalignment by analogizing it to a flap-door and using structured approach.Methods:The echocardiograms and magnetic resonance images of 35 patients with overriding/straddling tricuspid or mitral valve were evaluated to assess the following modifiers;the malaligned part of the septum,the reference structure,and the mechanism,direction and severity of malalignment.Results:The pathology included classic overriding tricuspid valve in 15,classic overriding mitral valve in 12,and overriding tricuspid valve with left juxtaposition of atrial appendages in 8.In classic overriding tricuspid valve,the ventricular septum was hinged to the anterior interventricular groove and its insertion to the posterior interventricular groove was displaced toward the right ventricle.The VSD primarily involved the inlet but also extended toward the anterior interventricular groove.In classic overriding mitral valve,the ventricular septum was hinged to the posterior interventricular groove and crux cordis.Its insertion to the anterior interventricular groove was displaced toward the left ventricle.The VSD primarily involved the anterior part but also extended toward the inlet.Overriding tricuspid valve with left juxtaposition of atrial appendages had a mild degree of malalignment with displacement/rotation of the atrioventricular junction.Evenly spaced short-axis images were most helpful in characterizing the pathology.Conclusions:Overriding/straddling atrioventricular valves can be easily understood by analogizing the atrial-ventricular septal malalignment to a flap-door and describing the pathology in a structured manner.Contrary to what has previously been known,the VSD is not limited to the inlet or outlet part of the ventricular septum.

关键词： Malalignment ventricular septal defect overriding straddling tricuspid mitral

Characteristic Tensor for Evaluation of Singular Stress Field Under Mixed-Mode Loadings

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Computer Modeling in Engineering & Sciences 2020年第2期122卷 415-432页

作者： Kei saito Tei Hirashima Ninshu Ma Hidekazu Murakawa JSOL Corporation 2-5-24 HarumiChuo-kuTokyo104-0053Japan. Osaka University 11-1 MihogaokaIbarakiOsaka567-0047Japan.

A characteristic tensor is defined using stress tensor averaged in a small circular domain at the crack tip and multiplied by the root of domain radius.It possesses the original stress tensor characteristics and has a simple relationship with conventional fracture-mechanics parameters.Therefore,it can be used to estimate stress intensity factors(SIFs)for cracks of arbitrary shape subjected to multiaxial stress loads.A characteristic tensor can also be used to estimate SIFs for kinked cracks.This study examines the relation between a characteristic tensor and SIFs to demonstrate the correlation between the characteristic tensor and fracture-mechanics parameters.Consequently,a single straight crack and a kinked crack of finite length existing in a twodimensional,infinite isotropic elastic body in a plane stress state,were considered to investigate the properties of the characteristic tensor under mixed-mode loadings.To demonstrate the practical utility of the characteristic tensor,the stress distribution obtained through finite element analysis(FEA)was used to estimate mixed-mode SIFs,and the values of estimated SIFs were compared with those obtained using an analytical solution.Results demonstrate that SIFs estimated under mixed-mode loadings exhibit a good agreement with the analytical values.This indicates that the proposed characteristictensor-based approach is effective in extracting features of singular stress fields at crack tips,and can be employed to estimate values of fracture-mechanics parameters,such as SIFs.Owing to its simplicity,the proposed approach can be easily incorporated in commercial FE codes for practical applications to simulate the crack-growth problem under both static and dynamic loading scenarios.The excellent applicability of the characteristic tensor greatly contributes to efficiency of the design process in industries.

关键词： Characteristic tensor stress-intensity factor mixed-mode loading kinked crack.