Shooting-Bouncing-Rays Technique to Model Mine Tunnels: Theory and Accuracy Validation

2021 ◽  
Vol 35 (11) ◽  
pp. 1268-1269
Author(s):  
Stephen Kasdorf ◽  
Blake Troksa ◽  
Jake Harmon ◽  
Cam Key ◽  
Branislav Notaros
Keyword(s):  
Ray Tracing ◽  
Excellent Agreement ◽  
Image Theory ◽  
Electromagnetic Modeling ◽  
Efficient Alternative ◽  
Commercial Solver ◽  
Mine Tunnels ◽  
Accuracy Validation

We present a shooting-bouncing rays technique for electromagnetic modeling of wireless propagation in long tunnels focusing on the accuracy of ray-tracing computation. The examples demonstrate excellent agreement with the traditionally more accurate but less efficient alternative ray-tracing approach using path corrections based on image theory and with a commercial solver.

Shooting-Bouncing-Rays Technique to Model Mine Tunnels: Algorithm Acceleration

2021 ◽  
Vol 35 (11) ◽  
pp. 1330-1331
Author(s):  
Stephen Kasdorf ◽  
Blake Troksa ◽  
Jake Harmon ◽  
Cam Key ◽  
Branislav Notaros
Keyword(s):  
Wireless Communication ◽  
Ray Tracing ◽  
Application Programming Interface ◽  
Underground Mine ◽  
Electromagnetic Analysis ◽  
Large Structures ◽  
Algorithm Acceleration ◽  
Application Programming ◽  
Programming Interface ◽  
Mine Tunnels

We present and discuss acceleration of a shooting and bouncing rays (SBR) algorithm for ray-tracing electromagnetic analysis of electrically very large structures such as underground mine tunnels at modern wireless communication frequencies. The acceleration is based on the parallelization of the SBR technique on NVIDIA GPUs using the OptiX application programming interface. The results show dramatic speedups of the parallel SBR algorithm compared with serial implementation.

The significance of SEM in the diagnosis of haematopoietic malignancies

1978 ◽  
Vol 36 (2) ◽  
pp. 314-315
Author(s):  
Etienne de Harven ◽  
Nina Lampen
Keyword(s):  
Room Temperature ◽  
Culture Medium ◽  
Cell Attachment ◽  
Ethanol Dehydration ◽  
Moist Chamber ◽  
Efficient Alternative ◽  
Mononuclear Leucocytes ◽  
Fast Quenching ◽  
Freeze Dryer ◽  
Scanning Electron

Samples of heparinized blood, or bone marrow aspirates, or cell suspensions prepared from biopsied tissues (nodes, spleen, etc. ) are routinely prepared, after Ficoll-Hypaque concentration of the mononuclear leucocytes, for scanning electron microscopy. One drop of the cell suspension is placed in a moist chamber on a poly-l-lysine pretreated plastic coverslip (Mazia et al., J. Cell Biol. 66:198-199, 1975) and fifteen minutes allowed for cell attachment. Fixation, started in 2. 5% glutaraldehyde in culture medium at room temperature for 30 minutes, is continued in the same fixative at 4°C overnight or longer. Ethanol dehydration is immediately followed by drying at the critical point of CO2 or of Freon 13. An efficient alternative method for ethanol dehydrated cells is to dry the cells at low temperature (-75°C) under vacuum (10-2 Torr) for 30 minutes in an Edwards-Pearse freeze-dryer (de Harven et al., SEM/IITRI/1977, 519-524). This is preceded by fast quenching in supercooled ethanol (between -90 and -100°C).

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