Beyond bandlimited sampling of speech spectral envelope imposed by the harmonic structure of voiced sounds

2013 ◽  
Author(s):  
Hideki Kawahara ◽  
Masanori Morise ◽  
Tomoki Toda ◽  
Ryuichi Nisimura ◽  
Toshio Irino
Keyword(s):  
Spectral Envelope ◽  
Harmonic Structure

Representation of Spectral and Temporal Envelope of Twitter Vocalizations in Common Marmoset Primary Auditory Cortex

2002 ◽  
Vol 87 (4) ◽  
pp. 1723-1737 ◽  
Author(s):  
Srikantan S. Nagarajan ◽  
Steven W. Cheung ◽  
Purvis Bedenbaugh ◽  
Ralph E. Beitel ◽  
Christoph E. Schreiner ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Social Contact ◽  
Primary Auditory Cortex ◽  
Common Marmoset ◽  
Spectral Envelope ◽  
Response Patterns ◽  
Temporal Envelope ◽  
Degraded Speech ◽  
Neurophysiological Data ◽  
Narrowband Channels

Cortical sensitivity in representations of behaviorally relevant complex input signals was examined in recordings from primary auditory cortical neurons (AI) in adult, barbiturate-anesthetized common marmoset monkeys ( Callithrix jacchus). We studied the robustness of distributed responses to natural and degraded forms of twitter calls, social contact vocalizations comprising several quasi-periodic phrases of frequency and AM. We recorded neuronal responses to a monkey's own twitter call (MOC), degraded forms of their twitter call, and sinusoidal amplitude modulated (SAM) tones with modulation rates similar to those of twitter calls. In spectral envelope degradation, calls with narrowband channels of varying bandwidths had the same temporal envelope as a natural call. However, the carrier phase was randomized within each narrowband channel. In temporal envelope degradation, the temporal envelope within narrowband channels was filtered while the carrier frequencies and phases remained unchanged. In a third form of degradation, noise was added to the natural calls. Spatiotemporal discharge patterns in AI both within and across frequency bands encoded spectrotemporal acoustic features in the call although the encoded response is an abstract version of the call. The average temporal response pattern in AI, however, was significantly correlated with the average temporal envelope for each phrase of a call. Response entrainment to MOC was significantly correlated with entrainment to SAM stimuli at comparable modulation frequencies. Sensitivity of the response patterns to MOC was substantially greater for temporal envelope than for spectral envelope degradations. The distributed responses in AI were robust to additive continuous noise at signal-to-noise ratios ≥10 dB. Neurophysiological data reflecting response sensitivity in AI to these forms of degradation closely parallel human psychophysical results on the intelligibility of degraded speech in quiet and noisy conditions.

Investigation of edge radiation intensification effect generated by periodic alignment of three-pole wigglers

2022 ◽  
Author(s):  
Shigeru Koda ◽  
Yuichi Takabayashi ◽  
Tatsuo Kaneyasu ◽  
Yoshitaka Iwasaki
Keyword(s):  
Numerical Study ◽  
Concentric Circle ◽  
Harmonic Structure ◽  
Characteristic Structure ◽  
K Value ◽  
Undulator Radiation ◽  
Peak Intensity ◽  
Edge Radiation ◽  
Radiation Properties ◽  
Large Gradient

Abstract The intensification effect of edge radiation due to the periodic alignment of three-pole wigglers was analytically and numerically investigated. The radiation properties were studied using a simple model that had an alternating alignment of straight sections and large gradient orbit sections due to the use of three-pole wigglers. The angular distribution of the radiation was concentrated on a concentric circle. The peak intensity of the radiation was roughly on the same order as that of the peak radiation of a planar undulator. The spectrum of the radiation had a characteristic structure that was rather similar to the higher harmonic structure of undulator radiation. A numerical study showed that a planar undulator with a specific K value satisfies approximately the radiation intensification condition due to the periodic alignment of the three-pole wigglers. The intensified edge radiation is included in the undulator radiation.

Calculation of the Harmonic Structure of Marine Propellers Torque and Thrust

1994 ◽  
Author(s):  
Dinu Taraza ◽  
Nicolae Buzbuchi ◽  
Jean Sever Popovici
Keyword(s):  
Harmonic Structure ◽  
Marine Propellers

Microstructure Evolution and Deformation Mechanisms of Harmonic Structure Designed Materials

2016 ◽  
Vol 879 ◽  
pp. 145-150
Author(s):  
Kei Ameyama ◽  
Sanjay Kumar Vajpai ◽  
Mie Ota
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Powder Metallurgy ◽  
Early Stage ◽  
High Strength ◽  
Plastic Instability ◽  
Structure Design ◽  
Harmonic Structure ◽  
Homogeneous Microstructure ◽  
Macro Scale

This paper presents the novel microstructure design, called Harmonic Structure, which gives structural metallic materials outstanding mechanical properties through an innovative powder metallurgy process. Homogeneous and ultra-fine grain (UFG) structure enables the materials high strength. However, such a “Homo-“ and “UFG” microstructure does not, usually, satisfy the need to be both strong and ductile, due to the plastic instability in the early stage of the deformation. As opposed to such a “Homo-and UFG“ microstructure, “Harmonic Structure” has a heterogeneous microstructure consisting of bimodal grain size together with a controlled and specific topological distribution of fine and coarse grains. In other words, the harmonic structure is heterogeneous on micro-but homogeneous on macro-scales. In the present work, the harmonic structure design has been applied to pure metals and alloys via a powder metallurgy route consisting of controlled severe plastic deformation of the corresponding powders by mechanical milling or high pressure gas milling, and subsequent consolidation by SPS. At a macro-scale, the harmonic structure materials exhibited superior combination of strength and ductility as compared to their homogeneous microstructure counterparts. This behavior was essentially related to the ability of the harmonic structure to promote the uniform distribution of strain during plastic deformation, leading to improved mechanical properties by avoiding or delaying localized plastic instability.

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