Manipulation of Skyrmion Motion Dynamics for Logical Device Application Mediated by Inhomogeneous Magnetic Anisotropy

Magnetic skyrmions are promising potential information carriers for future spintronic devices owing to their nanoscale size, non-volatility and high mobility. In this work, we demonstrate the controlled manipulation of skyrmion motion and its implementation in a new concept of racetrack logical device by introducing an inhomogeneous perpendicular magnetic anisotropy (PMA) via micromagnetic simulation. Here, the inhomogeneous PMA can be introduced by a capping nano-island that serves as a tunable potential barriers/well which can effectively modulate the size and shape of isolated skyrmion. Using the inhomogeneous PMA in skyrmion-based racetrack enables the manipulation of skyrmion motion behaviors, for instance, blocking, trapping or allowing passing the injected skyrmion. In addition, the skyrmion trapping operation can be further exploited in developing special designed racetrack devices with logic AND and NOT, wherein a set of logic AND operations can be realized via skyrmion–skyrmion repulsion between two skyrmions. These results indicate an effective method for tailoring the skyrmion structures and motion behaviors by using inhomogeneous PMA, which further provide a new pathway to all-electric skyrmion-based memory and logic devices.

LABORATORY MODEL OF MOBILE ROBOT WITH SECTIONAL MOVER

A laboratory model and simulation of the movement of a mobile robot with a sectional propeller are considered. The results of mathematical modeling of motion dynamics are presented.

Paddling with Maxine Sheets-Johnstone: Exploring the moving body in sport

This paper aims to contribute to the theoretical discussion and empirical application of phenomenology in the sociology of sport by drawing on Maxine Sheets-Johnstone’s theories. I propose that Sheets-Johnstone’s movement-focused phenomenology can be complementary to Merleau-Ponty’s phenomenology of the body in the analyses of sporting moves and the learning of new moves. I mainly applied two concepts from Sheets-Johnstone, tactile-kinesthetic/kinetic dynamics and emotion-motion dynamics, to explore the moving body in waka ama (outrigger canoe) paddling, based on my beginner’s and other competent paddlers’ experiences. Findings demonstrate that a moving/paddling body is spontaneously a tactile-kinesthetic/kinetic, emotion-motion and intercorporeal body. These bodily dimensions enrich our understandings of the ways of learning new movements, doing sport and doing sport together.

Computational Model of Motion Sickness Describing the Effects of Learning Exogenous Motion Dynamics

The existing computational models used to estimate motion sickness are incapable of describing the fact that the predictability of motion patterns affects motion sickness. Therefore, the present study proposes a computational model to describe the effect of the predictability of dynamics or the pattern of motion stimuli on motion sickness. In the proposed model, a submodel – in which a recursive Gaussian process regression is used to represent human features of online learning and future prediction of motion dynamics – is combined with a conventional model of motion sickness based on an observer theory. A simulation experiment was conducted in which the proposed model predicted motion sickness caused by a 900 s horizontal movement. The movement was composed of a 9 m repetitive back-and-forth movement pattern with a pause. Regarding the motion condition, the direction and timing of the motion were varied as follows: (a) Predictable motion (M_P): the direction of the motion and duration of the pause were set to 8 s; (b) Motion with unpredicted direction (M_dU): the pause duration was fixed as in (M_P), but the motion direction was randomly determined; (c) Motion with unpredicted timing (M_tU): the motion direction was fixed as in (M_P), but the pause duration was randomly selected from 4 to 12 s. The results obtained using the proposed model demonstrated that the predicted motion sickness incidence for (M_P) was smaller than those for (M_dU) and (M_tU) and no considerable difference was found between M_dU and M_tU. This tendency agrees with the sickness patterns observed in a previous experimental study in which the human participants were subject to motion conditions similar to those used in our simulations. Moreover, no significant differences were found in the predicted motion sickness incidences at different conditions when the conventional model was used.