19 research outputs found
Investigating the Usability of Collaborative Robot control through Hands-Free Operation using Eye gaze and Augmented Reality
This paper proposes a novel operation for controlling a mobile robot using a
head-mounted device. Conventionally, robots are operated using computers or a
joystick, which creates limitations in usability and flexibility because
control equipment has to be carried by hand. This lack of flexibility may
prevent workers from multitasking or carrying objects while operating the
robot. To address this limitation, we propose a hands-free method to operate
the mobile robot with a human gaze in an Augmented Reality (AR) environment.
The proposed work is demonstrated using the HoloLens 2 to control the mobile
robot, Robotnik Summit-XL, through the eye-gaze in AR. Stable speed control and
navigation of the mobile robot were achieved through admittance control which
was calculated using the gaze position. The experiment was conducted to compare
the usability between the joystick and the proposed operation, and the results
were validated through surveys (i.e., SUS, SEQ). The survey results from the
participants after the experiments showed that the wearer of the HoloLens
accurately operated the mobile robot in a collaborative manner. The results for
both the joystick and the HoloLens were marked as easy to use with
above-average usability. This suggests that the HoloLens can be used as a
replacement for the joystick to allow hands-free robot operation and has the
potential to increase the efficiency of human-robot collaboration in situations
when hands-free controls are needed.Comment: Accepted for publication in the Proceedings of the 2023 IEEE/RSJ
International Conference on Intelligent Robots and Systems (IROS 2023), 6
page
Formation of yttria-stabilized zirconia nanotubes by atomic layer deposition toward efficient solid electrolytes
Abstract We describe a fabrication strategy for preparing yttria-stabilized zirconia nanotube (YSZ-NT) arrays embedded in porous alumina membranes by means of template-directed atomic layer deposition (ALD) technique. The individual YSZ-NTs have a high aspect-ratio of well over 120, about ~ 110 nm in diameter, and ~ 14 µm in length. Interfacing the tube arrays with porous Pt was also introduced on the basis of partial etching technique in order to construct Pt/YSZ-NTs/Pt membrane electrode assembly (MEA) structures. The resulting YSZ-NTs MEAs show a 7 mm in diameter with a roughness factor of ~ 2. Area specific resistance was measured up to 1.84 Ω cm2 at 400 °C using H2 as fuel
Association Between Computerized Reaction Time, Short Physical Performance Battery and Berg Balance Scale in the Community-Dwelling Older Adults
Background : Falls, in older adults, can worsen physical functioning and lead to serious complications. Thus, as a means of preventive intervention, this high-risk group should be screened. The aim of the present study was to investigate whether reaction time is clinically applicable as a fall risk assessment tool. Methods : The study participants were community-dwelling older adults aged 65 years or older, who scored 24 or more in the Korean version of the Mini-Mental State Examination, and did not have difficulty with communication and comprehension. To investigate the relationship between hand reaction time and fall risk, we used items from a recently developed computerized apparatus, which includes 2 fall risk assessment tools: the Short Physical Performance Battery (SPPB) and Berg Balance Scale (BBS). Results : Reaction time was negatively correlated with the total SPPB (r=-0.314, p<0.001) and BBS scores (r=-0.164, p<0.001); the scores were higher when reaction times were lower. Multiple linear regression analyses also showed that the total SPPB (β=-0.30; 95% confidence interval [CI], -0.26 to -0.02) and BBS scores (β=-0.14; 95% CI, -0.26 to -0.02) significantly increased as the reaction time decreased. Conclusion : Reaction time was significantly correlated with the SPPB and BBS, confirming the possibility of its use in tools for fall risk assessment
Salami-like Electrospun Si Nanoparticle-ITO Composite Nanofibers with Internal Conductive Pathways for use as Anodes for Li-Ion Batteries
We report novel salami-like core–sheath
composites consisting
of Si nanoparticle assemblies coated with indium tin oxide (ITO) sheath
layers that are synthesized via coelectrospinning. Core–sheath
structured Si nanoparticles (NPs) in static ITO allow robust microstructures
to accommodate for mechanical stress induced by the repeated cyclical
volume changes of Si NPs. Conductive ITO sheaths can provide bulk
conduction paths for electrons. Distinct Si NP-based core structures,
in which the ITO phase coexists uniformly with electrochemically active
Si NPs, are capable of facilitating rapid charge transfer as well.
These engineered composites enabled the production of high-performance
anodes with an excellent capacity retention of 95.5% (677 and 1523
mAh g<sup>–1,</sup> which are based on the total weight of
Si-ITO fibers and Si NPs only, respectively), and an outstanding rate
capability with a retention of 75.3% from 1 to 12 C. The cycling performance
and rate capability of core–sheath-structured Si NP-ITO are
characterized in terms of charge-transfer kinetics
Direct methane solid oxide fuel cells based on catalytic partial oxidation enabling complete coking tolerance of Ni-based anodes
Solid oxide fuel cells (SOFCs) can oxidize diverse fuels by harnessing oxygen ions. Benefited by this feature, direct utilization of hydrocarbon fuels without external reformers allows for cost-effective realization of SOFC systems. Superior hydrocarbon reforming catalysts such as nickel are required for this application. However, carbon coking on nickel-based anodes and the low efficiency associated with hydrocarbon fueling relegate these systems to immature technologies. Herein, we present methane-fueled SOFCs operated under conditions of catalytic partial oxidation (CPOX). Utilizing CPOX eliminates carbon coking on Ni and facilitates the oxidation of methane. Ni-gadolinium-doped ceria (GDC) anode-based cells exhibit exceptional power densities of 1.35 W cm−2 at 650 °C and 0.74 W cm−2 at 550 °C, with stable operation over 500 h, while the similarly prepared Ni-yttria stabilized zirconia anode-based cells exhibit a power density of 0.27 W cm−2 at 650 °C, showing gradual degradation. Chemical analyses suggest that combining GDC with the Ni anode prevents the oxidation of Ni due to the oxygen exchange ability of GDC. In addition, CPOX operation allows the usage of stainless steel current collectors. Our results demonstrate that high-performance SOFCs utilizing methane CPOX can be realized without deterioration of Ni-based anodes using cost-effective current collectors
Characterization of Sputter-Deposited LiCoO<sub>2</sub> Thin Film Grown on NASICON-type Electrolyte for Application in All-Solid-State Rechargeable Lithium Battery
All-solid-state Li-rechargeable
batteries using a 500 nm-thick LiCoO<sub>2</sub> (LCO) film deposited
on two NASICON-type solid electrolyte substrates, LICGC (OHARA Inc.)
and Li<sub>1.3</sub>Al<sub>0.3</sub>Ti<sub>1.7</sub>(PO<sub>4</sub>)<sub>3</sub> (LATP), are constructed. The postdeposition annealing
temperature prior to the cell assembly is critical to produce a stable
sharp LCO/electrolyte interface and to develop a strong crystallographic
texture in the LCO film, conducive to migration of Li ions. Although
the cells deliver a limited discharge capacity, the cells cycled stably
for 50 cycles. The analysis of the LCO/electrolyte interfaces after
cycling demonstrates that the sharp interface, once formed by proper
thermal annealing, will remain stable without any evidence for contamination
and with minimal intermixing of the constituent elements during cycling.
Hence, although ionic conductivity of the NASICON-type solid electrolyte
is lower than that of the sulfide electrolytes, the NACSICON-type
electrolytes will maintain a stable interface in contact with a LCO
cathode, which should be beneficial to improving the capacity retention
as well as the rate capability of the all-solid state cell
Bounding Cache-related Preemption Delay for Real-time Systems
Cache memory is used in almost all computer systems today to bridge the ever increasing speed gap between the processor and main memory. However, its use in multitasking computer systems introduces additional preemption delay due to reloading of memory blocks that were replaced during preemption. This cache-related preemption delay poses a serious problem in real-time computing systems where predictability is of utmost importance. In this paper, we propose an enhanced technique for analyzing and thus, bounding the cache-related preemption delay in fixed-priority preemptive scheduling focusing on instruction caching. The proposed technique improves upon previous techniques in two important ways. First, the technique takes into account the relationship between a preempted task and the set of tasks that execute during the preemption when calculating the cache-related preemption delay. Second, the technique considers phasing of tasks to eliminate many infeasible task interactions. These tw..
Enhanced Analysis of Cache-related Preemption Delay in Fixed-priority Preemptive Scheduling
We propose an enhanced technique for analyzing and thus, bounding cache-related preemption delay in fixedpriority preemptive scheduling focusing on instruction caching. The proposed technique improves upon previous techniques in two important ways. First, the technique takes into account the relationship between a preempted task and the set of tasks that execute during the preemption when calculating the cache-related preemption delay. Second, the technique considers phasing of tasks to eliminate many infeasible task interactions. These two features are expressed as constraints of a linear programming problem whose solution gives a guaranteed upper bound on the cache-related preemption delay. This paper also compares the proposed technique with previous techniques. The results show that the proposed technique gives up to 60% tighter prediction of the worst case response time than the previous techniques. 1. Introduction In a real-time computing system, tasks have timing constraints in..
Chemically Driven Enhancement of Oxygen Reduction Electrocatalysis in Supported Perovskite Oxides
Perovskite oxides have the capacity
to efficiently catalyze the
oxygen reduction reaction (ORR), which is of fundamental importance
for electrochemical energy conversion. While the perovskite catalysts
have been generally utilized with a support, the role of the supports,
regarded as inert toward the ORR, has been emphasized mostly in terms
of the thermal stability of the catalyst system and as an ancillary
transport channel for oxygen ions during the ORR. We demonstrate a
novel approach to improving the catalytic activity of perovskite oxides
for solid oxide fuel cells by controlling the oxygen-ion conducting
oxide supports. Catalytic activities of (La<sub>0.8</sub>Sr<sub>0.2</sub>)<sub>0.95</sub>MnO<sub>3</sub> perovskite thin-film placed on different
oxide supports are characterized by electrochemical impedance spectroscopy
and X-ray absorption spectroscopy. These analyses confirm that the
strong atomic orbital interactions between the support and the perovskite
catalyst enhance the surface exchange kinetics by ∼2.4 times,
in turn, improving the overall ORR activity
Enhanced Analysis of Cache-related Preemption Delay in Fixed-priority Preemptive Scheduling
We propose an enhanced technique for analyzing and thus, bounding cache-related preemption delay in fixedpriority preemptive scheduling focusing on instruction caching. The proposed technique improves upon previous techniques in two important ways. First, the technique takes into account the relationship between a preempted task and the set of tasks that execute during the preemption when calculating the cache-related preemption delay. Second, the technique considers phasing of tasks to eliminate many infeasible task interactions. These two features are expressed as constraints of a linear programming problem whose solution gives a guaranteed upper bound on the cache-related preemption delay. This paper also compares the proposed technique with previous techniques. The results show that the proposed technique gives up to 60% tighter prediction of the worst case response time than the previous techniques. 1. Introduction In a real-time computing system, tasks have timing constraints in..