Chiral spin-wave edge modes in dipolar magnetic thin films

Based on a linearized Landau-Lifshitz equation, we show that two-dimensional periodic allay of ferromagnetic particles coupled with magnetic dipole-dipole interactions supports chiral spin-wave edge modes, when subjected under the magnetic field applied perpendicular to the plane. The mode propagates along a one-dimensional boundary of the system in a unidirectional way and it always has a chiral dispersion within a band gap for spin-wave volume modes. Contrary to the well-known Damon-Eshbach surface mode, the sense of the rotation depends not only on the direction of the field but also on the strength of the field; its chiral direction is generally determined by the sum of the so-called Chern integers defined for spin-wave volume modes below the band gap. Using simple tight-binding descriptions, we explain how the magnetic dipolar interaction endows spin-wave volume modes with non-zero Chern integers and how their values will be changed by the field.Comment: 18 pages, 16 figures, some trivial typo in equations are fixe

Data-Importance-Aware Bandwidth-Allocation Scheme for Point-Cloud Transmission in Multiple LIDAR Sensors

This paper addresses bandwidth allocation to multiple light detection and ranging (LIDAR) sensors for smart monitoring, which a limited communication capacity is available to transmit a large volume of point-cloud data from the sensors to an edge server in real time. To deal with the limited capacity of the communication channel, we propose a bandwidth-allocation scheme that assigns multiple point-cloud compression formats to each LIDAR sensor in accordance with the spatial importance of the point-cloud data transmitted by the sensor. Spatial importance is determined by estimating how objects, such as cars, trucks, bikes, and pedestrians, are likely to exist since regions where objects are more likely to exist are more useful for smart monitoring. A numerical study using a real point-cloud dataset obtained at an intersection indicates that the proposed scheme is superior to the benchmarks in terms of the distributions of data volumes among LIDAR sensors and quality of point-cloud data received by the edge server

The research about editing system of performance information for player piano - Make inferences about both handed musical composition by using DP matching system -

We have developed a system that allows a piano to perform automatically. In order to play music in the manner of a live pianist, we must add expression to the piano’s performance. Therefore, we have developed an interactive musical editing system that utilizes a database to edit music more efficiently.The 2021 International Conference on Artificial Life and Robotics (ICAROB 2021), January 21-24, 2021, Higashi-Hiroshima (オンライン開催に変更

Analysis of the implementation of information disclosure ordinances in Japan: the effect on the income of mayors and chief executives in local governments

This paper attempts to investigate how information transparency affects human behavior. Thus, we empirically examine the influence of information disclosure ordinances on the income of mayors and chief executives in local governments in Japan. For the estimation, we use panel data of local governments covering 1999–2010, during which time many local governments implemented such ordinances. The key finding is that the income of mayors and chief executives in local governments decreased after the implementation of the ordinances. Furthermore, as the years passed, the income declined further. Hence, information disclosure regarding local government reduces the income of top officials and its influence becomes greater over time. Although the income of mayors and chiefs executives is open information without the need for an ordinance, it provided transparency regarding their work performance. Furthermore, the effect of the ordinance did not depend on the mayors or chief executives’ income level in 1999. Therefore, the reduction of income is mainly due to the government’s accountability rather than citizens’ inequality aversion

Effects of galactic magnetic field on the UHECR correlation studies with starburst galaxies

We estimate the biases caused by the coherent deflection of cosmic rays due to the Galactic magnetic field (GMF) in maximum-likelihood analysis for searches of ultrahigh-energy cosmic ray (UHECR) sources in the literature. We simulate mock event datasets with a set of assumptions for the starburst galaxy (SBG) source model (arXiv:1801.06160), coherent deflection by a GMF model (arXiv:1204.3662,arXiv:1210.7820), and mixed-mass composition (arXiv:1901.03338); we then conduct a maximum-likelihood analysis without accounting for the GMF in the same manner as previous studies. We find that the anisotropic fraction $f_{\rm ani}$ is estimated systematically lower than the true value. We estimate the true parameters which are compatible with the best-fit parameters reported in (arXiv:1801.06160), and find that except for a narrow region with a large anisotropic fraction and small separation angular scale a wide parameter space is still compatible with the experimental results. We also develop a maximum-likelihood method that takes into account the GMF model and confirm in the MC simulations that we can estimate the true parameters within a 1$\sigma$ contour under the ideal condition that we know the event-by-event mass and the GMF

Farming strategy of African smallholder farmers in transition from traditional to alternative agriculture : the case of the Nupe in central Nigeria

It is worthwhile to understand farming strategies of smallholder farmers in sub-Saharan Africa, especially those of farmers who are in transition from traditional to alternative agriculture in terms of adoption of innovative technologies. In a case study of inland valleys in central Nigeria, we investigated the farming strategy of Nupe farmers who have a long-term tradition of wet rice cultivation and indigenous methods of land preparation for soil, water and weed management. In this region, a new method of land preparation has recently been introduced along with a recommendation to use improved seeds and chemical fertilizers. Our findings reveal that Nupe farmers directly sow traditional seeds and apply a marginal amount of fertilizer to paddy plots prepared by labor-saving methods on drought-prone hydromorphic valley fringes and flood-susceptible valley bottoms, whereas they preferentially transplanted improved seedlings and applied a relatively large quantity of fertilizer to paddy fields prepared by a labor-intensive and mechanized method on a valley position where they can access to optimum water condition (less risky against the drought and flood)