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Surgical outcomes of degenerative cervical spinal disease are dependent on the selection of surgical techniques. Although a standardized decision cannot be made in an actual clinical setting, continued education is provided to standardize the medical practice among surgeons. Therefore, it is necessary to supervise and regularly update overall surgical outcomes. This study aimed to compare the rate of additional surgery between anterior and posterior surgeries for degenerative cervical spinal disease using the National Health Insurance Service-National Sample Cohort (NHIS-NSC) nationwide patient database. The NHIS-NSC is a population-based cohort with about a million participants. This retrospective cohort study included 741 adult patients (> 18 years) who underwent their first cervical spinal surgery for degenerative cervical spinal disease. The median follow-up period was 7.3 years. An event was defined as the registration of any type of cervical spinal surgery during the follow-up period. Event-free survival analysis was used for outcome analysis, and the following factors were used as covariates for adjustment: location of disease, sex, age, type of insurance, disability, type of hospital, Charles comorbidity Index, and osteoporosis. Anterior cervical surgery was selected for 75.0% of the patients, and posterior cervical surgery for the remaining 25.0%. Cervical radiculopathy due to foraminal stenosis, hard disc, or soft disc was the primary diagnosis in 78.0% of the patients, and central spinal stenosis was the primary diagnosis in 22.0% of them. Additional surgery was performed for 5.0% of the patients after anterior cervical surgery and 6.5% of the patients after posterior cervical surgery (adjusted subhazard ratio, 0.83; 95% confidence interval, 0.40–1.74). The rates of additional surgery were not different between anterior and posterior cervical surgeries. The results would be helpful in evaluating current practice as a whole and adjusting the health insurance policy.

We studied the stability of skyrmion formation and its abnormal dynamic motions in magnetic nanotubes with perpendicular magnetic anisotropy with respect to the tube surface. Unlike planar geometry, skyrmions, which are formed in an elliptical shape, are stabilized, to a greater or lesser degree, by the curved geometry, depending on the sign of the Dzyaloshinskii-Moriya Interaction (DMI) constant. The positive and negative signs of the DMI constant play a crucial role in the formation of skyrmions on the curved surface. These effects become stronger as the diameter of the tube decreases, quantitatively evidencing that the curvature-induced DM-like interaction also contributes to the stability of skyrmion formation. The dynamic modes of the skyrmion in the tubes are found to be as follows: two in-plane gyration modes in the counterclockwise (CCW) and clockwise (CW) rotation senses, and one out-of-plane breathing mode. On the other hand, in contrast to the planar geometry, the initial CCW gyration motion turns out to be a linear translational motion in the circumferential direction of the tube for cases where the strength of axial AC magnetic fields is greater than a threshold field strength. The direction of the translational motions is determined by the skyrmion helicity governed by the sign of the interfacial DMI constant. This work provides further physical insight into the static and dynamic properties of skyrmions formed in curved-geometry systems and also suggests its potential application to information processing devices.

Searching for desired 3D models is not easy because many of them are not well labeled; annotations often contain inconsistent information (e.g., uploaders' personal way of naming) and lack important details (e.g., detailed ornaments and pattern) of each model. We introduce PolySquare, a search engine for 3D models based on tag propagation---the process of assigning existing tags to other similar but unlabeled models considering important local properties. For instance, a tag `wheel' of a wheelchair can be spread out to other objects with wheels. Furthermore, PolySquare allows people to interactively refine the search results by iteratively including desired shapes and excluding unwanted ones. We evaluate the performance of tag propagation by measuring the precision-recall of propagation results with various similarity thresholds and demonstrate the effectiveness of the use of local features. We also showcase how PolySquare handles the unrefined tags through a case study using real 3D model data from Google Poly.

We experimentally demonstrate strongly enhanced coupling between excited magnons in an Yttrium Iron Garnet (YIG) film and microwave photons in an inverted pattern of split-ring resonator (noted as ISRR). The anti-crossing effects of the ISRR’s photon mode and the YIG’s magnon modes were found from |S21|-versus-frequency measurements for different strengths and directions of externally applied magnetic fields. The spin-number-normalized coupling strength (i.e. single spin-photon coupling) $${g}_{{\rm{eff}}}/2\pi \sqrt{N}$$ g eff / 2 π N was determined to 0.194 Hz ($${g}_{{\rm{eff}}}/2\pi $$ g eff / 2 π = 90 MHz) at 3.7 GHz frequency. Furthermore, we found that additional fine features in the anti-crossing region originate from the excitation of different spin-wave modes (such as the magnetostatic surface and the backward-volume magnetostatic spin-waves) rather than the Kittel-type mode. These spin-wave modes, as coupled with the ISRR mode, modify the anti-crossing effect as well as their coupling strength. An equivalent circuit model very accurately reproduced the observed anti-crossing effect and its coupling strength variation with the magnetic field direction in the planar-geometry ISRR/YIG hybrid system. This work paves the way for the design of new types of high-gain magnon-photon coupling systems in planar geometry.

We report a micromagnetic numerical study on different quasi-crystal formations of magnetic vortices in a rich variety of dynamic transient states in soft magnetic nano-disks. Only the application of spin-polarized dc currents to a single magnetic vortex leads to the formation of topological-soliton quasi-crystals composed of different configurations of skyrmions with positive and negative half-integer numbers (magnetic vortices and antivortices). Such topological object formations in soft magnets, not only in the absence of Dzyaloshinskii- Moriya interaction but also without magnetocrystalline anisotropy, are discussed in terms of two different topological charges, the winding number and the skyrmion number. This work offers an insight into the dynamic topological-spin-texture quasi-crystal formations in soft magnets.

Annotating chart images for training machine learning models is tedious and repetitive especially in that chart images often have a large number of visual elements to annotate. We present Autotator, a semi-automatic chart annotation system that automatically provides suggestions for three annotation tasks such as labeling a chart type, annotating bounding boxes, and associating a quantity. We also present a web-based interface that allows users to interact with the suggestions provided by the system. Finally, we demonstrate a use case of our system where an annotator builds a training corpus of bar charts.

We report the experimental demonstration of an abnormal, opposite anti-crossing effect in a photon-magnon-coupled system that consists of an Yttrium Iron Garnet film and an inverted pattern of split-ring resonator structure (noted as ISRR) in a planar geometry. It is found that the normal shape of anti-crossing dispersion typically observed in photon-magnon coupling is changed to its opposite anti-crossing shape just by changing the position/orientation of the ISRR's split gap with respect to the microstrip line axis along which ac microwave currents are applied. Characteristic features of the opposite anti-crossing dispersion and its linewidth evolution are analyzed with the help of analytical derivations based on electromagnetic interactions. The observed opposite anti-crossing dispersion is ascribed to the compensation of both intrinsic damping and coupling-induced damping in the magnon modes. This compensation is achievable by controlling the relative strength and phase of oscillating magnetic fields generated from the ISRR's split gap and the microstrip feeding line. The position/orientation of an ISRR's split gap provides a robust means of controlling the dispersion shape of anti-crossing and its damping in a photon-magnon coupling, thereby offering more opportunity for advanced designs of microwave devices., Comment: 23 pages, 4 figures

We conceptually designed a robust nano-scale waveguide structure suitable for potential use as a spin-wave duplexer that allows signal propagation only of selected narrow-band frequencies and duplex transmission in a three-port device comprising a receiver, a transmitter, and their common antenna. The waveguide structure combines three different arms and a circular ring, both made of nanostrip waveguides and a single magnetic material for reliably controllable propagations of spin waves. We attribute the observed duplex transmission of spin waves of narrow pass bands to scattering of spin waves by edge solitons placed at contact areas between the arms and the circular ring. This work proposes the first concept of nano-scale magnonic duplexers operating beyond GHz-frequency ranges.

We report on a micromagnetic numerical simulation study of dynamic coupling between neighboring skyrmions periodically arranged in narrow-width nanostrips. We explored the coupled gyration modes and their characteristic dispersions in terms of the interdistance between the neighboring skyrmions. The application of perpendicular magnetic fields allows for the control and modification of the dispersion of the coupled gyration modes. The coupled gyration modes of individual skyrmions might provide a new type of information carrier in narrow-width straight and curved nanostrips, as driven by magnetic interactions in such continuous thin films.

We performed micromagnetic numerical calculations to explore a cylindrical nanotube's magnetization dynamics and domain-wall (DW) motions driven by eigen-circular-rotating magnetic fields of different frequencies. We discovered the presence of two different localized DW oscillations as well as asymmetric ferromagnetic resonance precession and azimuthal spin-wave modes at the corresponding resonant frequencies of the circular-rotating fields. Associated with these intrinsic modes, there exist very contrasting DW motions of different speed and propagation direction for a given DW chirality. The direction and speed of the DW propagation were found to be controllable according to the rotation sense and frequency of noncontact circular-rotating fields. Furthermore, spin-wave emissions from the moving DW were observed at a specific field frequency along with their Doppler effect. This work furthers the fundamental understanding of soft magnetic nanotubes' intrinsic dynamic modes and spin-wave emissions and offers an efficient means of manipulating the speed and direction of their DW propagations.

We explored strong coupling of dynamic breathing modes in one-dimensional (1D) skyrmion lattices periodically arranged in thin-film nanostrips. The coupled breathing modes exhibit characteristic concave-down dispersions that represent the in-phase high-energy mode at zero wavenumber (k = 0) and the anti-phase low-energy mode at the Brillouin zone boundary (k = kBZ). The band width of the allowed modes increases with decreasing inter-distance between nearest-neighboring skyrmions. Furthermore, the collective breathing modes propagate very well through the thin-film nanostrips, as fast as 200–700 m/s, which propagation is controllable by the strength of magnetic fields applied perpendicularly to the film plane. The breathing modes in 1D skyrmion lattices potentially formed in such nanostrips possibly can be used as information carriers in information processing devices.

Spin-wave (SW) modes excited in cylindrical nanotubes of finite length were investigated using finite-element micromagnetic simulations. From the simulation results along with the relevant analytical interpretation, we found unique dynamic modes representative of a variety of standing SW modes. Those modes are controllable not only according to the geometric confinements of given nanotubes but also by the relative configuration of the vortex-chirality at both ends of the nanotubes. The asymmetric (symmetric) spin-wave dispersion originates from nonreciprocal (reciprocal) spin-wave propagations from the parallel (antiparallel) configuration of vortex chiralities at both ends of the nanotubes. Using a simple analytical model, we estimated the quantized dispersions of the excited modes that agree with the simulation results. This work facilitates further understanding of discrete standing SW modes in three-dimensional curvilinear nano-elements, such as cylindrical nanotubes, and opens up a broader and deeper...

Titanium oxynitride (TiN x O y ) films are investigated for application as a bipolar plate coating material in a polymer electrolyte membrane fuel cell (PEMFC). TiN x O y films with various amounts of oxygen are deposited on stainless-steel substrates by inductively coupled plasma (ICP) assisted reactive sputtering by changing the oxygen gas flow rate. The interfacial contact resistance (ICR) and the corrosion resistance of the TiN x O y films are measured under PEMFC simulated conditions. When the amount of oxygen in the TiN x O y film is approximately 2 flow rate ≤0.2 sccm), the corrosion resistance is enhanced considerably, whereas the interfacial contact resistance does not change. The corrosion current density decreases from 8 × 10 −6 A cm −2 for the TiN-coated sample to 2.7 × 10 −6 A cm −2 at 0.6 V vs. SCE as a result of oxygen incorporation in the TiN film. The ICR value remains at 2.5 mΩ cm 2 at 150 N cm −2 . When a small amount of oxygen is added to the TiN film, it is postulated that the oxygen atoms locate at the column and grain boundaries, and thus prevent corrosive media from penetrating into the substrate while not deteriorating the electrical property of the film.

We performed micromagnetic numerical calculations to explore the novel dynamics of two vortex cores magnetically coupled via long-range dipolar interactions and short-range exchange interactions in a single element of spherical nano-shells. One vortex core is located in the upper half-shell and the other in the lower half-shell. Under a given static magnetic field, they show unique coupled dynamic motions that have yet to be reported so far. For the parallel core orientations, they show slow and large-amplitude orbital motions around the static field direction, and both cores' positions on the surface are out-of-phase with each other. This motion resembles the precession motion of a single vortex core around the static magnetic field direction in a nanosphere. In addition to such a precession-like motion, each core simultaneously shows relatively fast and small-amplitude gyration-like motions that move along with the precession-like motion. The superposition of the two distinct dynamic modes results in an...