Accuracy Assessment of Two Electromagnetic Articulographs: Northern Digital Inc. WAVE and Northern Digital Inc. VOX

Purpose This study compares two electromagnetic articulographs manufactured by Northern Digital, Inc.: the NDI Wave System (from 2008) and the NDI Vox-EMA System (from 2020). Method Four experiments were completed: (a) comparison of statically positioned sensors, (b) tracking dynamic movements of sensors manipulated using a motor-driven LEGO apparatus, (c) tracking small and large movements of sensors mounted in a rigid bar manipulated by hand, and (d) tracking movements of sensors rotated on a circular disc. We assessed spatial variability for statically positioned sensors, variability in the transduced Euclidean distances between sensor pairs, and missing data rates. For sensors tracking circular movements, we compared the fit between fitted ideal circles and actual trajectories. Results The average sensor pair tracking error (i.e., the standard deviation of the Euclidean distances) was 1.37 mm for the WAVE and 0.12 mm for the VOX during automated trials at the fastest speed, and 0.35 mm for the WAVE and 0.14 mm for the VOX during the tracking of large manual movements. The average standard deviation of the fitted circle radii charted by manual circular disc movements was 0.72 mm for the WAVE sensors and 0.14 mm for the VOX sensors. There was no significant difference between the WAVE and the VOX in the number of missing frames. Conclusions In general, the VOX system significantly outperformed the WAVE on measures of both static precision and dynamic accuracy (automated and manual). For both systems, positional precision and spatial variability were influenced by the sensors' position relative to the field generator unit (worse when further away). Supplemental Material https://doi.org/10.23641/asha.14787846

Interdigital Coupled Compact FSS Reflector for UWB Antenna Gain Enhancement

A compact UWB FSS reflector is presented based on interdigital structure for gain enhancement of an UWB antenna. An equivalent circuit approach is proposed for the analysis of the FSS reflector. The reflector comprises a 6 × 6 array of unit cell dimension 6 mm × 6 mm and which is very compact. The reflector gives a linear phase response over UWB band. A UWB monopole antenna is designed with a half circular disc structure based on microstrip technology. A maximum of 5 dBi gain enhancement is achieved with this compact FSS reflector when placed at a distance below the antenna. The measured results closely follow the simulated ones which proves feasibility of this design.

Highly sensitive refractive index sensor by floating nano-particles in the solution for the detection of glucose/fructose concentration

In this research, an optimum design for better usage of field resonance was proposed. More interaction of the field that formed around nano-particles with a solution which has refractive index variations substantially can increase the sensitivity of the plasmonic biosensors. More interaction could be provided by floating nano-particles in the solution. The proposed structure, which has peak plasmonic resonance, has better light sensing features in comparison to similar non-floating structures. While without floating nano-particle, sensitivity is 265.8 nm/RIU with the realization of the full floating nano-particles, the sensitivity of the structure with elliptic disc and circular disc nano-particles are 574.2 nm/RIU and 425 nm/RIU, respectively. FWHM (Full width at half maximum) of the structure with elliptic disc and circular disc nano-particles are 57.4 nm and 49.4 nm, respectively. In presence of meshed SiO2 network and pseudo-floating form, sensitivity and FWHM of the structure are 504 nm/RIU and 58.4 nm for elliptic discs and 372 nm/RIU and 49.9 nm for circular discs, respectively.

Nonlinear deformation of circular discrete ribbed plate under influence of pulse loading

The stress-strain state of a circular disc, discretely finned in a circle, under the influence of the pulse loading, is numerically investigated. Thus the geometric nonlinearity between displacement and deformation is taken into account. The structure consists of boarding and reinforced ribs, the materials of which are the same and obey Hooke's law. The sections of the ribs are constant. The height of the ribs and their locations are specified using a unit function. It is considered that the plate is deformed under the influence of the pulsed loading. A numerical method is used to solve the problem.