scholarly journals Dispersion and topological characteristics of permutative polyatomic phononic crystals

2019 ◽  
Vol 475 (2226) ◽  
pp. 20190022 ◽  
Author(s):  
H. Al Ba'ba'a ◽  
M. Nouh ◽  
T. Singh
Keyword(s):  
Function Analysis ◽  
Finite Lattice ◽  
Wave Dispersion ◽  
Phononic Crystals ◽  
Mathematical Treatment ◽  
Plot Analysis ◽  
Local Arrangement ◽  
Transfer Function Analysis ◽  
Unit Cells ◽  
The Individual

This work presents a comprehensive mathematical treatment of phononic crystals (PCs) which comprise a finite lattice of repeated polyatomic unit cells. Wave dispersion in polyatomic lattices is susceptible to changes in the local arrangement of the monatoms (subcells) constituting the individual unit cell. We derive and interpret conditions leading to identical and contrasting band structures as well as the possibility of distinct eigenmodes as a result of cyclic and non-cyclic cellular permutations. Different modes associated with cyclic permutations yield topological invariance, which is assessed via the winding number of the complex eigenmode. Wave topology variations in the polyatomic PCs are quantified and conditions required to support edge modes in such lattices are established. Next, a transfer function analysis of finite polyatomic PCs is used to explain the formation of multiple Bragg band gaps as well as the emergence of truncation resonances within them. Anomalies arising from the truncation of the infinite lattice are further exploited to design mirror symmetrical edge modes in an extended lattice. We conclude with a generalized explanation of the band gap evolution mechanism based on the Bode plot analysis.

scholarly journals Spatial Unmasking Effect on Speech Reception Threshold in the Median Plane

2020 ◽  
Vol 10 (15) ◽  
pp. 5257
Author(s):  
Nathan Berwick ◽  
Hyunkook Lee
Keyword(s):  
Transfer Function ◽  
Input Signal ◽  
Function Analysis ◽  
Median Plane ◽  
Speech Reception ◽  
Transfer Function Analysis ◽  
Spatial Unmasking ◽  
Head Related Transfer Function ◽  
Speech Reception Thresholds ◽  
Energy Weighting

This study examined whether the spatial unmasking effect operates on speech reception thresholds (SRTs) in the median plane. SRTs were measured using an adaptive staircase procedure, with target speech sentences and speech-shaped noise maskers presented via loudspeakers at −30°, 0°, 30°, 60° and 90°. Results indicated a significant median plane spatial unmasking effect, with the largest SRT gain obtained for the −30° elevation of the masker. Head-related transfer function analysis suggests that the result is associated with the energy weighting of the ear-input signal of the masker at upper-mid frequencies relative to the maskee.

Transfer Function Analysis and Broadband Scalable Model for On-Chip Spiral Inductors

2011 ◽  
Vol 59 (7) ◽  
pp. 1696-1708 ◽  
Author(s):  
Huang Wang ◽  
Lingling Sun ◽  
Jun Liu ◽  
Huanhuan Zou ◽  
Zhiping Yu ◽  
...  
Keyword(s):  
Transfer Function ◽  
Function Analysis ◽  
Transfer Function Analysis ◽  
Spiral Inductors ◽  
On Chip

scholarly journals A novel method for assessing cerebral autoregulation in preterm infants using transfer function analysis

2015 ◽  
Vol 79 (3) ◽  
pp. 453-459 ◽  
Author(s):  
Zachary A. Vesoulis ◽  
Steve M. Liao ◽  
Shamik B. Trivedi ◽  
Nathalie El Ters ◽  
Amit M. Mathur
Keyword(s):  
Transfer Function ◽  
Preterm Infants ◽  
Cerebral Autoregulation ◽  
Function Analysis ◽  
Transfer Function Analysis ◽  
Novel Method

scholarly journals Image Simulations of Ge Twin Boundaries.

1992 ◽  
Vol 295 ◽  
Author(s):  
Stuart Mckernan ◽  
C. Barry Carter
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
High Angle ◽  
Structural Units ◽  
Twin Boundaries ◽  
Large Unit ◽  
Unit Cells ◽  
The Individual ◽  
Image Simulations

AbstractGeneral high-angle tilt grain boundaries may be described by an arrangement of repeating structural units. Some grain-boundary defects may also be modeled by the incorporation of structural units of related boundary structures into the boundary. The simulation of these structures requires the use of prohibitively large unit cells. The possibility of modeling these boundaries by the superposition of image simulations of the individual structural units isinvestigated.

Midlife Aerobic Exercise and Dynamic Cerebral Autoregulation: Associations with Baroreflex Sensitivity and Central Arterial Stiffness

2021 ◽  
Author(s):  
Tsubasa Tomoto ◽  
Justin Repshas ◽  
Rong Zhang ◽  
Takashi Tarumi
Keyword(s):  
Arterial Stiffness ◽  
Aerobic Exercise ◽  
Cerebral Autoregulation ◽  
Baroreflex Sensitivity ◽  
Function Analysis ◽  
Middle Aged ◽  
Age Related ◽  
Transfer Function Analysis ◽  
Carotid Distensibility ◽  
Dynamic Cerebral Autoregulation

Midlife aerobic exercise may significantly impact age-related changes in the cerebro- and cardiovascular regulations. This study investigated the associations of midlife aerobic exercise with dynamic cerebral autoregulation (dCA), cardiovagal baroreflex sensitivity (BRS), and central arterial stiffness. Twenty middle-aged athletes (MA) who had aerobic training for >10 years were compared with 20 young (YS) and 20 middle-aged sedentary (MS) adults. Beat-to-beat cerebral blood flow velocity, blood pressure (BP), and heart rate were measured at rest and during forced BP oscillations induced by repeated sit-stand maneuvers at 0.05 Hz. Transfer function analysis was used to calculate dCA and BRS parameters. Carotid distensibility was measured by ultrasonography. MA had the highest peak oxygen uptake (VO2peak) among all groups. During forced BP oscillations, MS showed lower BRS gain than YS, but this age-related reduction was absent in MA. Conversely, dCA was similar among all groups. At rest, BRS and dCA gains at low frequency (~0.1 Hz) were higher in the MA compared with MS and YS groups. Carotid distensibility was similar between MA and YS groups, but it was lower in the MS. Across all subjects, VO2peak was positively associated with BRS gains at rest and during forced BP oscillations (r=0.257~0.382, p=0.003~0.050) and carotid distensibility (r=0.428~0.490, p=0.001). Furthermore, dCA gain at rest and carotid distensibility were positively correlated with BRS gain at rest in YS and MA groups (all p<0.05). These findings suggest that midlife aerobic exercise improves central arterial elasticity and BRS which may contribute to CBF regulation through dCA.

Structural Modification Simulation: Sensitivity Analysis and the Reanalysis of Modified Structure

1991 ◽  
Author(s):  
Debao Li ◽  
Fangze Li ◽  
Peiming Xu
Keyword(s):  
Sensitivity Analysis ◽  
Transfer Function ◽  
Coordinate Transformation ◽  
Degrees Of Freedom ◽  
Structural Modification ◽  
Function Analysis ◽  
Dump Truck ◽  
Analysis Method ◽  
Transfer Function Analysis ◽  
Dynamic Modification

Abstract This paper deals with the dynamic modification simulation of the structure. The expressions of sensitivity analysis of the system with non-proportional damping and proportional damping are derived at first. As for the reanalysis of modified structure, here we deal with the system to which the modification do not cause any change of the degrees of freedom. Transfer function analysis method and the method of twice coordinate transformation are expounded. As a successful example, the modification simulation of the frame of a dump truck is explained.

Indexing of powder diffraction patterns for low-symmetry lattices by the successive dichotomy method

1991 ◽  
Vol 24 (6) ◽  
pp. 987-993 ◽  
Author(s):  
A. Boultif ◽  
D. Louër
Keyword(s):  
Success Rate ◽  
Powder Diffraction ◽  
Input Parameter ◽  
Mathematical Treatment ◽  
Monoclinic Symmetry ◽  
Unit Cells ◽  
Rate Calculation ◽  
Diffraction Patterns ◽  
Low Symmetry ◽  
Very High

The dichotomy method for indexing powder diffraction patterns for low-symmetry lattices is studied in terms of an optimization of bound relations used in the comparison of observed data with the calculated patterns generated at each level of the analysis. A rigorous mathematical treatment is presented for monoclinic and triclinic cases. A new program, DICVOL91, has been written, working from the cubic end of the symmetry sequence to triclinic lattices. The search of unit cells is exhaustive within input parameter limits, although a few restrictions for the hkl indices of the first two diffraction lines have been introduced in the study of triclinic symmetry. The efficiency of the method has been checked by means of a large number of accurate powder data, with a very high success rate. Calculation times appeared to be quite reasonable for the majority of examples, down to monoclinic symmetry, but were less predictable for triclinic cases. Applications to all symmetries, including cases with a dominant zone, are discussed.

scholarly journals Control-Bounded Analog-to-Digital Conversion

2021 ◽  
Author(s):  
Hampus Malmberg ◽  
Georg Wilckens ◽  
Hans-Andrea Loeliger
Keyword(s):  
Input Signal ◽  
Digital Control ◽  
Function Analysis ◽  
Analog Filters ◽  
Analog Filter ◽  
Analog To Digital ◽  
Analog To Digital Conversion ◽  
Delta Sigma ◽  
Transfer Function Analysis ◽  
Cascade Structure

AbstractA control-bounded analog-to-digital converter consists of a linear analog system that is subject to digital control, and a digital filter that estimates the analog input signal from the digital control signals. Such converters have many commonalities with delta–sigma converters, but they can use more general analog filters. The paper describes the operating principle, gives a transfer function analysis, and describes the digital filtering. In addition, the paper discusses two examples of such architectures. The first example is a cascade structure reminiscent of, but simpler than, a high-order MASH converter. The second example combines two attractive properties that have so far been considered incompatible. Its nominal conversion noise (assuming ideal components) essentially equals that of the first example. However, its analog filter is a fully connected network to which the input signal is fed in parallel, which potentially makes it more robust against nonidealities.

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