Metalog is a modern replacement for syslogd and klogd. The logged messages
can be dispatched according to their facility, urgency, program name and/or
Perl-compatible regular expressions. Log files can be automatically rotated
when they exceed a certain size or age. External shell scripts (e.g., mail)
can be launched when specific patterns are found.
Metalog is easier to configure than syslogd and syslog-ng, accepts unlimited
number of rules and has (switchable) memory bufferization for maximal
performance.
提取信號七個基于瞬時信息的特征：零中心歸一化瞬時幅度功率譜密度的最大值,零中心歸一化瞬時幅度絕對值的標準偏差，零中心非弱信號段瞬時相位非線性分量絕對值標準偏差，零中心非弱信號段瞬時相位非線性分量標準偏差，零中心歸一化的非弱信號段瞬時頻率絕對值的標準偏差，一個信號段的歸一化瞬時頻率功率譜密度的最大值，根據信號 QPSK 和16QAM在 XI 軸投影的不同表現，提出特征參數。
