Severity: Warning
Message: file_get_contents(https://...@pubfacts.com&api_key=b8daa3ad693db53b1410957c26c9a51b4908&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 176
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 176
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 250
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3122
Function: getPubMedXML
File: /var/www/html/application/controllers/Detail.php
Line: 575
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 489
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
Earthquakes, forest fires, mudslides and other natural disasters occur frequently in recent years. They usually occur in the mountainous and dense forests, where local communication facilities do not exist or have been destroyed by the disasters. Adverse geographical environment poses a huge challenge to emergency communications and rescue. This paper presents comparative studies on multi-carrier transmission schemes in the mountainous and dense forest environment. The comprehensive communication performance for various multi-carrier waveform schemes, has been extensively analyzed by using the Stanford University Interim channel model. Simulation results show that the pruned discrete Fourier transform spread filter bank multi-carrier scheme exhibits generally the best performance in terms of transmission rate and distance for most operation modes.
Download full-text PDF |
Source |
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9547074 | PMC |
http://dx.doi.org/10.1038/s41598-022-20895-0 | DOI Listing |
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