Subjective visual vertical(SVV)and subjective visual horizontal(SVH)tests can be used to evaluate the perception of verticality and horizontality,respectively,and can aid the diagnosis of otolith dysfunction in clinic...Subjective visual vertical(SVV)and subjective visual horizontal(SVH)tests can be used to evaluate the perception of verticality and horizontality,respectively,and can aid the diagnosis of otolith dysfunction in clinical practice.In this study,SVV and SVH screen version tests are implemented using virtual reality(VR)equipment;the proposed test method promotes a more immersive feeling for the subject while using a simple equipment configuration and possessing excellent mobility.To verify the performance of the proposed VR-based SVV and SVH tests,a reliable comparison was made between the traditional screen-based SVV and SVH tests and the proposed method,based on 30 healthy subjects.The average results of our experimental tests on the VR-based binocular SVV and SVH equipment were−0.15◦±1.74 and 0.60◦±1.18,respectively.The proposed VR-based method satisfies the normal tolerance for horizontal or vertical lines,i.e.,a±3◦error,as defined in previous studies,and it can be used to replace existing test methods.展开更多
The friction and wear properties of interpenetrating phase composites(IPC) SiC3D/Al sliding against graphite/SiC(G/SiC) composites were investigated using a sub-scale brake dynamometer. The testing conditions included...The friction and wear properties of interpenetrating phase composites(IPC) SiC3D/Al sliding against graphite/SiC(G/SiC) composites were investigated using a sub-scale brake dynamometer. The testing conditions included a braking pressure of 1.25 MPa and an initial braking speed(IBS) of 200-350 km/h in a braking process of high-speed train according to the scale-conversion rules. The tribo-couple materials were characterized using scanning electron microscopy(SEM), X-ray diffractometry(XRD), and energy-dispersive X-ray spectrometry(EDS). It is found that the matching tribo-couple features low friction surface temperature, reliable friction factor, and high durability. The continuous lubricating mechanically-mixed layer(MML) forms gradually on the worn surfaces of ring in the friction process. The MML is heterogeneous, which greatly controls wear rate and coefficient of friction(COF) of the composites. The wear mechanism of SiC3D/Al is typically abrasive wear at an IBS of 200-300 km/h. When the IBS increases to 350 km/h, oxidation wear and delamination are observed. The friction behavior of the tribo-couple predicted using Solidwork simulation software agrees well with the experimental results. The tribo-couple meets the requirement of emergency braking of high-speed train.展开更多
Design and implementation of a personal computer (PC) based measurement circuits & system that containing signals’ sensing and generation are demonstrated in this study. The instrument can be easily operated via ...Design and implementation of a personal computer (PC) based measurement circuits & system that containing signals’ sensing and generation are demonstrated in this study. The instrument can be easily operated via a user-friendly interface consisted of some functional keys displayed on the PC screen. Compact design of the hardware for the two units (signals’ sensing and generation) is made in a plug-in style of PC input/output (I/O) card so that no extra space for the instrument is needed. Design concepts for the hardware and software of the instrument are described. Functional performances of the setup of signals’ sensing and generation are tested. The results show user-friendly function and well-behaved performance for the package design.展开更多
基金supported by the Soonchunhyang University Research Fund and 2018 Ulsan University Hospital Research Grant(UUH-2018-12)(Grantee:JYP,http://www.uuh.ulsan.kr).The authors are grateful for their supports.
文摘Subjective visual vertical(SVV)and subjective visual horizontal(SVH)tests can be used to evaluate the perception of verticality and horizontality,respectively,and can aid the diagnosis of otolith dysfunction in clinical practice.In this study,SVV and SVH screen version tests are implemented using virtual reality(VR)equipment;the proposed test method promotes a more immersive feeling for the subject while using a simple equipment configuration and possessing excellent mobility.To verify the performance of the proposed VR-based SVV and SVH tests,a reliable comparison was made between the traditional screen-based SVV and SVH tests and the proposed method,based on 30 healthy subjects.The average results of our experimental tests on the VR-based binocular SVV and SVH equipment were−0.15◦±1.74 and 0.60◦±1.18,respectively.The proposed VR-based method satisfies the normal tolerance for horizontal or vertical lines,i.e.,a±3◦error,as defined in previous studies,and it can be used to replace existing test methods.
基金Project(51465014)supported by the National Natural Science Foundation of ChinaProject(1099043)supported by Scientific and Technological Research Program of Guangxi,ChinaProjects(2014GXNSFAA118351,2014GXNSFAA118329,2012GXNSFBA053156)supported by the Natural Science Foundation of Guangxi,China
文摘The friction and wear properties of interpenetrating phase composites(IPC) SiC3D/Al sliding against graphite/SiC(G/SiC) composites were investigated using a sub-scale brake dynamometer. The testing conditions included a braking pressure of 1.25 MPa and an initial braking speed(IBS) of 200-350 km/h in a braking process of high-speed train according to the scale-conversion rules. The tribo-couple materials were characterized using scanning electron microscopy(SEM), X-ray diffractometry(XRD), and energy-dispersive X-ray spectrometry(EDS). It is found that the matching tribo-couple features low friction surface temperature, reliable friction factor, and high durability. The continuous lubricating mechanically-mixed layer(MML) forms gradually on the worn surfaces of ring in the friction process. The MML is heterogeneous, which greatly controls wear rate and coefficient of friction(COF) of the composites. The wear mechanism of SiC3D/Al is typically abrasive wear at an IBS of 200-300 km/h. When the IBS increases to 350 km/h, oxidation wear and delamination are observed. The friction behavior of the tribo-couple predicted using Solidwork simulation software agrees well with the experimental results. The tribo-couple meets the requirement of emergency braking of high-speed train.
文摘Design and implementation of a personal computer (PC) based measurement circuits & system that containing signals’ sensing and generation are demonstrated in this study. The instrument can be easily operated via a user-friendly interface consisted of some functional keys displayed on the PC screen. Compact design of the hardware for the two units (signals’ sensing and generation) is made in a plug-in style of PC input/output (I/O) card so that no extra space for the instrument is needed. Design concepts for the hardware and software of the instrument are described. Functional performances of the setup of signals’ sensing and generation are tested. The results show user-friendly function and well-behaved performance for the package design.
