Locating multiple incoherent sound sources in three‐dimensional space.

Triangulation is commonly used for source localization and most triangulation applications are based on intersection of the bearing direction to locate a source on a two-dimensional plane. In this paper, two new mathematical models (a basic model and an improved one) that expands the traditional triangulation concept to three-dimensional space are developed to locate multiple incoherent sound sources. The basic model uses four microphones and concentrates on solving a set of three quadratic equations simultaneously. The improved model requires more than four microphones and uses the solution from the basic model, as well as analyzing the intersection of bearing angles. Redundancy checks on the time differences of arrival are added to further reduce the source localization error in the improved model. Moreover, the input data are pre-processed and de-noised through filtering and windowing to enhance the effective signal to noise ratio. Various sound sources are tested, including transient, impulsive, continuous, broad-band, and narrow-band sounds. Numerical simulations and experimental validation using the real world sound sources are conducted. The impacts of the source direction/source detection range on the accuracy of source localization results are examined and discussed.

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A Problem of Evasion of Two Controlled Objects from a Group of Pursuers in the Three-Dimensional Space

Journal of Automation and Information Sciences ◽

10.1615/jautomatinfscien.v34.i1.10 ◽

2002 ◽

Vol 34 (1) ◽

pp. 26

Author(s):

Arkadiy A. Chikriy ◽

Alexey P. Ignatenko

Keyword(s):

Dimensional Space ◽

Three Dimensional ◽

Three Dimensional Space

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Extension of the Spatial PDI Model to Three Dimensions

Perceptual and Motor Skills ◽

10.2466/pms.1997.84.1.176 ◽

1997 ◽

Vol 84 (1) ◽

pp. 176-178

Author(s):

Frank O'Brien

Keyword(s):

Population Density ◽

Dimensional Space ◽

Finite Lattice ◽

Three Dimensional ◽

Upper Bounds ◽

Three Dimensions ◽

Lower And Upper Bounds ◽

Density Index ◽

Three Dimensional Space

The author's population density index ( PDI) model is extended to three-dimensional distributions. A derived formula is presented that allows for the calculation of the lower and upper bounds of density in three-dimensional space for any finite lattice.

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A Peptoid with Extended Shape in Water

10.26434/chemrxiv.7552139 ◽

2019 ◽

Author(s):

Jumpei Morimoto ◽

Yasuhiro Fukuda ◽

Takumu Watanabe ◽

Daisuke Kuroda ◽

Kouhei Tsumoto ◽

...

Keyword(s):

Spectroscopic Analysis ◽

Dimensional Space ◽

Three Dimensional ◽

Biomolecular Recognition ◽

Biological Application ◽

New Class ◽

Proteolytic Resistance ◽

Pharmacokinetic Properties ◽

Optically Pure ◽

Three Dimensional Space

<div> <div> <div> <p>“Peptoids” was proposed, over decades ago, as a term describing analogs of peptides that exhibit better physicochemical and pharmacokinetic properties than peptides. Oligo-(N-substituted glycines) (oligo-NSG) was previously proposed as a peptoid due to its high proteolytic resistance and membrane permeability. However, oligo-NSG is conformationally flexible and is difficult to achieve a defined shape in water. This conformational flexibility is severely limiting biological application of oligo-NSG. Here, we propose oligo-(N-substituted alanines) (oligo-NSA) as a new peptoid that forms a defined shape in water. A synthetic method established in this study enabled the first isolation and conformational study of optically pure oligo-NSA. Computational simulations, crystallographic studies and spectroscopic analysis demonstrated the well-defined extended shape of oligo-NSA realized by backbone steric effects. The new class of peptoid achieves the constrained conformation without any assistance of N-substituents and serves as an ideal scaffold for displaying functional groups in well-defined three-dimensional space, which leads to effective biomolecular recognition. </p> </div> </div> </div>

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