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Hiroshi Igarashi

Publications and source records attributed to Hiroshi Igarashi.

7 recordsLinked to original sources
arXiv2025

Exploring Remote Collaborative Tasks: The Impact of Avatar Representation on Dyadic Haptic Interactions in Shared Virtual Environments

This study is the first to explore the interplay between haptic interaction and avatar representation in Shared Virtual Environments (SVEs). Specifically, how these factors shape users' sense of social presence during dyadic collaborations, while assessing potential effects on task performance. In a series of experiments, participants performed the collaborative task with haptic interaction under four avatar representation conditions: avatars of both participant and partner were displayed, only the participant's avatar was displayed, only the partner's avatar was displayed, and no avatars were displayed. The study finds that avatar representation, especially of the partner, significantly enhances the perception of social presence, which haptic interaction alone does not fully achieve. However, neither the presence nor the type of avatar representation impacts the task performance or participants' force effort of the task, suggesting that haptic interaction provides sufficient interaction cues for the execution of the task. These results underscore the significance of integrating both visual and haptic modalities to optimize remote collaboration experiences in virtual environments, ensuring effective communication and a strong sense of social presence.

cs.HC↗
arXiv2019

Improvement of photosynthetic rate evaluation by plant bioelectric potential using illuminating information and a neural network

The plant bioelectric potential is believed to be a suitable real-time and noninvasive method that can be used to evaluate plant activities, such as the photosynthetic reaction. The amplitude of the bioelectric potential response when plants are illuminated is correlated with the photosynthetic rate. However, practically, the bioelectric potential is affected by various cultivation parameters. This study analyzes the relationship between the bioelectric potential response and the illuminating parameters using a neural network to improve the accuracy of the photosynthetic rate evaluation. The variation of the illuminating colors to the plant affected the relationship between the amplitude of the bioelectric potential response and the photosynthetic rate; therefore, evaluating the photosynthetic rate using the amplitude is difficult. The analysis result shows that the correlation coefficient between the actual measured photosynthetic rate and the estimated photosynthetic rate by the neural network is 0.95. The photosynthetic rate evaluation using the bioelectric potential response is improved and this correlation coefficient is greater than that analyzed by the neural network using only the illuminating parameters. This result indicates that the information on the plant bioelectric potential response contributed to the accurate estimation of the photosynthetic rate.

eess.SP↗
arXiv2005

Dirac Operator Zero-modes on a Torus

We study Dirac operator zero-modes on a torus for gauge background with uniform field strengths. Under the basic translations of the torus coordinates the wave functions are subject to twisted periodic conditions. In a suitable torus coordinates the zero-mode wave functions can be related to holomorphic functions of the complex torus coordinates. We construct the zero-mode wave functions that satisfy the twisted periodic conditions. The chirality and the degeneracy of the zero-modes are uniquely determined by the gauge background and are consistent with the index theorem.

hep-th↗
arXiv2002

More about the axial anomaly on the lattice

We study the axial anomaly defined on a finite-size lattice by using a Dirac operator which obeys the Ginsparg-Wilson relation. When the gauge group is U(1), we show that the basic structure of axial anomaly on the infinite lattice, which can be deduced by a cohomological analysis, persists even on (sufficiently large) finite-size lattices. For non-abelian gauge groups, we propose a conjecture on a possible form of axial anomaly on the infinite lattice, which holds to all orders in perturbation theory. With this conjecture, we show that a structure of the axial anomaly on finite-size lattices is again basically identical to that on the infinite lattice. Our analysis with the Ginsparg-Wilson Dirac operator indicates that, in appropriate frameworks, the basic structure of axial anomaly is quite robust and it persists even in a system with finite ultraviolet and infrared cutoffs.

hep-lat↗
arXiv1997

Remark on Pauli-Villars Lagrangian on the Lattice

It is interesting to superimpose the Pauli-Villars regularization on the lattice regularization. We illustrate how this scheme works by evaluating the axial anomaly in a simple lattice fermion model, the Pauli-Villars Lagrangian with a gauge non-invariant Wilson term. The gauge non-invariance of the axial anomaly, caused by the Wilson term, is remedied by a compensation among Pauli-Villars regulators in the continuum limit. A subtlety in Frolov-Slavnov's scheme for an odd number of chiral fermions in an anomaly free complex gauge representation, which requires an infinite number of regulators, is briefly mentioned.

hep-th↗
arXiv1996

Super-Virasoro Anomaly, Super-Weyl Anomaly and the Super-Liouville Action for 2D Supergravity

The relation between super-Virasoro anomaly and super-Weyl anomaly in $N=1$ NSR superstring coupled with 2D supergravity is investigated from canonical theoretical view point. The WZW action canceling the super-Virasoro anomaly is explicitly constructed. It is super-Weyl invariant but nonlocal functional of 2D supergravity. The nonlocality can be remedied by the super-Liouvlle action, which in turn recovers the super-Weyl anomaly. The final gravitational effective action turns out to be local but noncovariant super-Liouville action, describing the dynamical behavior of the super-Liouville fields. The BRST invariance of this approach is examined in the superconformal gauge and in the light-cone gauge.

hep-th↗