The evaluation of source strength using a microphone array over a hard reflecting surface

1987 ◽  
Vol 82 (S1) ◽  
pp. S39-S39
Author(s):  
Stewart A. L. Glegg ◽  
Richard C. Smart
Keyword(s):  
Microphone Array ◽  
Source Strength ◽  
Reflecting Surface

Anisotropic, Multiply Scattered Radiation From an Arbitrary, Cylindrical Source in an Infinite Slab

1965 ◽  
Vol 87 (2) ◽  
pp. 167-172 ◽  
Author(s):  
J. H. Chin ◽  
S. W. Churchill
Keyword(s):  
Approximate Analytical Solution ◽  
Numerical Results ◽  
Source Strength ◽  
Open Surface ◽  
Scattered Energy ◽  
Infinite Slab ◽  
Cylindrical Source ◽  
Scattering Material ◽  
Reflecting Surface ◽  
Oil Particles

An approximate, analytical solution is developed for the intensity of electromagnetic radiation resulting from a line or cylindrical source located within and normal to the boundaries of an infinite slab of purely scattering material. The source strength is allowed to vary arbitrarily along the line or cylinder, and the slab is considered to have one absorbing (or open) surface and one partially reflecting surface. The problem represents an idealization of the attenuation of thermal radiation from a nuclear fireball within a layer of fog or a dispersion of oil particles. The six-flux resolution of scattered energy proposed by Chu and Churchill is utilized. In general, machine computations are needed to obtain numerical results. Approximations are suggested for use in the indicated computations. Illustrative numerical results are presented.

Active control of the scattered radiation with a reflecting surface

2019 ◽  
Vol 67 (3) ◽  
pp. 190-196
Author(s):  
Ning Han
Keyword(s):  
Control System ◽  
Active Control ◽  
Scattered Radiation ◽  
Sound Pressure ◽  
Sound Field ◽  
Control Area ◽  
Mirror Image ◽  
Three Dimension ◽  
Control Effect ◽  
Reflecting Surface

Based on a prediction method of the scattered sound pressure, an active control system was proposed in previous work for the three-dimension scattered radiation, where all the relevant simulations and experiments were implemented in three-dimensional free sound field. However, for practical applications, such as the anti-eavesdropping system or the stealth system for submarines, the sound field conditions are usually complex, and the most common case is the one with reflecting surface. It is questionable whether the previous control system is still effective in non-free sound field, or what improvements should be operated to ensure the control effect. In this article, based on the mirror image principle, two methods of calculating the control source strengths are proposed for the scattered radiation control, and numerical simulations with one-channel and multi-channel system are implemented to detect the corresponding control effect. It is seen that the local active control for the scattered radiation is still effective, and the reduction of the sound pressure level as well as the control area is extended with the increasement of the error sensors and control sources.

Soil and ecological division into districts of the Baikal region

2018 ◽  
Vol 940 (10) ◽  
pp. 54-64 ◽  
Author(s):  
I.A. Belozertseva ◽  
A.A. Sorokovoj
Keyword(s):  
Baikal Region ◽  
Soil Cover ◽  
Soil Formation ◽  
Forest Steppe ◽  
Leading Role ◽  
Soil Cover Structure ◽  
Reflecting Surface ◽  
Heat And Moisture ◽  
Made In

On the basis of long-term researches of soils in the territory of Russia and Mongolia soil and ecological division into districts of the Baikal region is carried out. At division into districts the whole set of an environment of soil formation was considered. On the map of soil and ecological division into districts 13 mountain, mid-mountain, low-mountain taiga, foothill, hollow-valley, forest-steppe and steppe provinces reflecting surface device originality as the ratio of balance of heat and moisture forming a basis to zoning is shown against the background of difficult orography are allocated. In total 42 districts on lithologic-geomorphological features are allocated. In formation of distinctions of a soil cover of these provinces the leading role is played by bioclimatic factors and inside them the lithologic-geomorphological ones. In the view of structural approach of the district they are considered as territories with a certain natural change of several types of the soil cover structure caused by features of a relief and the parent rock. The map is made in the MapInfo program. It is revealed that on ill-defined width zoning of soils the vertical one which has a greater influence on soils of this region is imposed. Soils of the Baikal region are not similar to the soils located at the same latitude of the flat European territory of Russia. Zone soils of this territory are specific and original.

Intelligent reflecting surface enhanced indoor terahertz communication systems

2020 ◽  
Vol 24 ◽  
pp. 100284 ◽  
Author(s):  
Xinying Ma ◽  
Zhi Chen ◽  
Wenjie Chen ◽  
Yaojia Chi ◽  
Zhuoxun Li ◽  
...  
Keyword(s):  
Communication Systems ◽  
Surface Enhanced ◽  
Terahertz Communication ◽  
Reflecting Surface
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