One of the classic approaches in PRNGs is the middle square method in which with a simple mathe-matical model generating pseudorandom numbers in high speed and minimum correlation between output numbers. Despite these...One of the classic approaches in PRNGs is the middle square method in which with a simple mathe-matical model generating pseudorandom numbers in high speed and minimum correlation between output numbers. Despite these unique characteristics, the method contains weaknesses that a broader application of this algo- rithm will face. In this paper is studied middle square method and then a logistic chaotic map is introduced with its specific features and its improved weaknesses via using these characteristics. Finally the NIST tests suite s are presented, in order to detect the specific characteristics expected from truly random sequences.展开更多
This research uses Japan facsimile data in May-September of 2011-2015 in Fumeng and Zhangwu County of Fuxin, Liaoning, China as the site selection for high altitude NECV circulation background, using statistical and s...This research uses Japan facsimile data in May-September of 2011-2015 in Fumeng and Zhangwu County of Fuxin, Liaoning, China as the site selection for high altitude NECV circulation background, using statistical and synoptic methods testing the combination of test and Analysis on Japanese numerical precipitation prediction and error. The prediction equation of cold vortex precipitation in the region is established by SPSS software. It is predicted whether the product predicts precipitation, water vapor condition and vertical velocity according to the Japanese numerical forecast. The results show that the fitting rate is 88% in the past 5 years, and the rate of cold vortex precipitation in the summer of 2016 is 89%.展开更多
为做好ECMWF(European Centre for Medium-Range Weather Forecasting)模式本地化释用,提高四川省降水预报准确率,对四川省2020—2021年7—9月模式各量级降水预报系统性偏差规律分析发现,该模式预报的雨日较实况偏多,尤其是攀西地区和...为做好ECMWF(European Centre for Medium-Range Weather Forecasting)模式本地化释用,提高四川省降水预报准确率,对四川省2020—2021年7—9月模式各量级降水预报系统性偏差规律分析发现,该模式预报的雨日较实况偏多,尤其是攀西地区和川西高原;预报的大雨日数盆地西南部及攀西地区多于实况,而盆地南部少于实况。然后,基于分位数映射法对模式预报的24 h累积降水开展大量级降水订正试验与检验。基于分位数映射法订正后,暴雨及以上量级TS(Threat Score)提高7%~15%,且各量级降水TS均高于多模式集成客观预报产品2%~4%,大雨及以上、暴雨及以上量级命中率提高10%~20%,订正后雨带位置特别是暴雨落区与实况更接近。展开更多
文摘One of the classic approaches in PRNGs is the middle square method in which with a simple mathe-matical model generating pseudorandom numbers in high speed and minimum correlation between output numbers. Despite these unique characteristics, the method contains weaknesses that a broader application of this algo- rithm will face. In this paper is studied middle square method and then a logistic chaotic map is introduced with its specific features and its improved weaknesses via using these characteristics. Finally the NIST tests suite s are presented, in order to detect the specific characteristics expected from truly random sequences.
文摘This research uses Japan facsimile data in May-September of 2011-2015 in Fumeng and Zhangwu County of Fuxin, Liaoning, China as the site selection for high altitude NECV circulation background, using statistical and synoptic methods testing the combination of test and Analysis on Japanese numerical precipitation prediction and error. The prediction equation of cold vortex precipitation in the region is established by SPSS software. It is predicted whether the product predicts precipitation, water vapor condition and vertical velocity according to the Japanese numerical forecast. The results show that the fitting rate is 88% in the past 5 years, and the rate of cold vortex precipitation in the summer of 2016 is 89%.
文摘为做好ECMWF(European Centre for Medium-Range Weather Forecasting)模式本地化释用,提高四川省降水预报准确率,对四川省2020—2021年7—9月模式各量级降水预报系统性偏差规律分析发现,该模式预报的雨日较实况偏多,尤其是攀西地区和川西高原;预报的大雨日数盆地西南部及攀西地区多于实况,而盆地南部少于实况。然后,基于分位数映射法对模式预报的24 h累积降水开展大量级降水订正试验与检验。基于分位数映射法订正后,暴雨及以上量级TS(Threat Score)提高7%~15%,且各量级降水TS均高于多模式集成客观预报产品2%~4%,大雨及以上、暴雨及以上量级命中率提高10%~20%,订正后雨带位置特别是暴雨落区与实况更接近。
