We introduce novel methods to determine optimum detection thresholds for the Progressive Multi-Channel Correlation (PMCC) algorithm used by the International Data Centre (IDC) to perform infrasound and seismic station...We introduce novel methods to determine optimum detection thresholds for the Progressive Multi-Channel Correlation (PMCC) algorithm used by the International Data Centre (IDC) to perform infrasound and seismic station-level nuclear-event detection. Receiver Operating Characteristic (ROC) curve analysis is used with real ground truth data to determine the trade-off between the probability of detection (PD) and the false alarm rate (FAR) at various detection thresholds. Further, statistical detection theory via maximum a posteriori and Bayes cost approaches is used to determine station-level optimum “family” size thresholds before detections should be considered for network-level processing. These threshold-determining methods are extensible for family-characterizing statistics other than “size,” such as a family’s collective F-statistic or signal-to-noise ratio (SNR). Therefore, the reliability of analysts’ decisions as to whether families should be preserved for network-level processing can only benefit from access to multiple, independent, optimum decision thresholds based upon size, F-statistic, SNR, etc.展开更多
Maritime treaty English has peculiarity in linguistic characteristics. As a sub-register of legal language, maritime treaty English is considered to be very difficult to comprehend. This paper attempts to analyze its ...Maritime treaty English has peculiarity in linguistic characteristics. As a sub-register of legal language, maritime treaty English is considered to be very difficult to comprehend. This paper attempts to analyze its stylistic characteristics at the lexicalsyntactic level based on four international maritime treaties including STCW, SOLAS, MARPOL and ISM Code. It is concluded that understanding of these characteristics is both necessary and helpful in learning and teaching maritime treaty English.展开更多
文摘We introduce novel methods to determine optimum detection thresholds for the Progressive Multi-Channel Correlation (PMCC) algorithm used by the International Data Centre (IDC) to perform infrasound and seismic station-level nuclear-event detection. Receiver Operating Characteristic (ROC) curve analysis is used with real ground truth data to determine the trade-off between the probability of detection (PD) and the false alarm rate (FAR) at various detection thresholds. Further, statistical detection theory via maximum a posteriori and Bayes cost approaches is used to determine station-level optimum “family” size thresholds before detections should be considered for network-level processing. These threshold-determining methods are extensible for family-characterizing statistics other than “size,” such as a family’s collective F-statistic or signal-to-noise ratio (SNR). Therefore, the reliability of analysts’ decisions as to whether families should be preserved for network-level processing can only benefit from access to multiple, independent, optimum decision thresholds based upon size, F-statistic, SNR, etc.
文摘Maritime treaty English has peculiarity in linguistic characteristics. As a sub-register of legal language, maritime treaty English is considered to be very difficult to comprehend. This paper attempts to analyze its stylistic characteristics at the lexicalsyntactic level based on four international maritime treaties including STCW, SOLAS, MARPOL and ISM Code. It is concluded that understanding of these characteristics is both necessary and helpful in learning and teaching maritime treaty English.
