The results show that the factors with higher occurrence frequency are the subtropical high systems in the Northern Hemisphere and the Eastern Hemisphere.
With the increase of the vehicle amount, traffic accident occurrence frequency in China has risen.
The paper extracts the text features based on a method of word co-occurrence frequency, which is related to the semantics of document.
Finally, this paper discusses the occurrence frequency and distribution area of light pollution at sea, providing reference for ships likely to sail around these waters and further research.
According to the travel accident occurrence frequency the defect of open mining transportation system, the grey theory is used, the grey forecasting model is established and forecast.
Differences lie in the occurrence frequency and in the use of strategies such as "suggestion of alternative" and "address forms".
At present various types of wind damage will have a trend of increase, whether occurrence frequency or strength.
