Nagoya Institute of Technology

About: Nagoya Institute of Technology is a education organization based out in Nagoya, Japan. It is known for research contribution in the topics: Thin film & Turbulence. The organization has 10766 authors who have published 19140 publications receiving 255696 citations. The organization is also known as: Nagoya Kōgyō Daigaku & Nitech.

Understanding the Structural Evolution and Redox Mechanism of a NaFeO2–NaCoO2 Solid Solution for Sodium-Ion Batteries

Abstract: Na-ion batteries have become promising candidates for large-scale energy-storage systems because of the abundant Na resources and they have attracted considerable academic interest because of their unique behavior, such as their electrochemical activity for the Fe3+/Fe4+ redox couple. The high-rate performance derived from the low Lewis-acidity of the Na+ ions is another advantage of Na-ion batteries and has been demonstrated in NaFe1/2Co1/2O2 solutions. Here, a solid solution of NaFeO2-NaCoO2 is synthesized and the mechanisms behind their excellent electrochemical performance are studied in comparison to those of their respective end-members. The combined analysis of operando X-ray diffraction, ex situ X-ray absorption spectroscopy, and density functional theory (DFT) calculations for Na1– x Fe1/2Co1/2O2 reveals that the O3-type phase transforms into a P3-type phase coupled with Na+/vacancy ordering, which has not been observed in O3-type NaFeO2. The substitution of Co for Fe stabilizes the P3-type phase formed by sodium extraction and could suppress the irreversible structural change that is usually observed in O3-type NaFeO2, resulting in a better cycle retention and higher rate performance. Although no ordering of the transition metal ions is seen in the neutron diffraction experiments, as supported by Monte-Carlo simulations, the formation of a superlattice originating from the Na+/vacancy ordering is found by synchrotron X-ray diffraction for Na0.5Fe1/2Co1/2O2, which may involve a potential step in the charge/discharge profiles.

A new hand exoskeleton device for rehabilitation using a three-layered sliding spring mechanism

Abstract: In this paper, a new hand exoskeleton device using a three-layered sliding spring mechanism is presented. In contrast to state of the art hand exoskeleton mechanisms (typically link, wire or pneumatically driven), the proposed mechanism is driven through large deformations of the compliant mechanism body. The mechanism can be made compact and lightweight by adequately positioning the compliant elements. In addition, the mechanism is designed to distribute 1-DOF actuated linear motion into three rotational motions of the finger joints, which translate into natural finger flexion/extension. The primary application of the proposed mechanism is to provide robotic support during physical therapy at the hospital (e.g. Continuous Passive Motion). However, thanks to its light and wearable structure, the proposed device could also be used at home as an assistive/therapeutic device to support activities of daily living. We introduce the mechanical structure of the three-layered sliding spring mechanism, present a prototype implementation as a hand exoskeleton device, and provide a preliminary evaluation.

Randomized initialization protocols for ad hoc networks

Abstract: Ad hoc networks are self-organizing entities that are deployed on demand in support of various events including collaborative computing, multimedia classroom, disaster-relief, search-and-rescue, interactive mission planning, and law enforcement operations. One of the fundamental tasks that have to be addressed when setting up an ad hoc network (AHN, for short) is initialization. This involves assigning each of the n stations in the AHN a distinct ID number (e.g., a local IP address) in the range from 1 to n. Our main contribution is to propose efficient randomized initialization protocols for AHNs. We begin by showing that if the number n of stations is known beforehand, an n-station, single-channel AHN can be initialized with probability exceeding 1-(1/n), in en+O(/spl radic/(nlogn)) time slots, regardless of whether the AHN has collision detection capability. We then go on to show that even if n is not known in advance, an n-station, single-channel AHN with collision detection can be initialized with probability exceeding 1-(1/n), in (10n)/3+O(/spl radic/(n 1n n)) time slots. Using this protocol as a stepping stone, we then present an initialization protocol for the n-station, k-channel AHN with collision detection that terminates with probability exceeding 1-(1/n), in (10n)/(3k)+O(/spl radic/(n 1n n)/k) time slots. Finally, we look at the case where the collision detection capability is not present. Our first result in this direction is to show that the task of electing a leader in an n-station, single-channel AHN can be completed with probability exceeding 1-(1/n), in fewer than 11.37(iog n)/sup 2/+2.39 log n time slots. This leader election protocol allows us to design an initialization protocol for the n-station, single-channel AHN with no collision detection that terminates with probability exceeding 1-(1/n), in fewer than 5.67n+O(/spl radic/(n 1n n)) time slots, even if n is not known beforehand. We then discuss an initialization protocol for the n-station, k-channel AHN with no collision detection that terminates with probability exceeding 1-(1/n), in fewer than 5.67(n/k)+O(/spl radic/(n 1n n)/k) time slots, whenever k/spl les/n/((log n)/sup 3/).