The nonlinear filter Boolean function of LILI-128 stream cipher generator is studied in this paper. First we measure the complexity of the stream ciphers sequence of LILI-128 stream cipher generator and obtain the sho...The nonlinear filter Boolean function of LILI-128 stream cipher generator is studied in this paper. First we measure the complexity of the stream ciphers sequence of LILI-128 stream cipher generator and obtain the shortest bit stream sequence reconstructed Boolean function of nonlinear filter in LILI-128 stream cipher generator. Then the least nonlinear Boolean function of generating stream cipher sequence is reconstructed by clusterig, nonlinear predictive and nonlinear synchronization from shortest bit stream sequence. We have verified the correctness of our reconstruction result by simulating the block diagram of Lili-128 keystream generator using our getting Boolean function and implement designers’ reference module of Lili-128 stream cipher public online, and two methods produce the same synchronous keystream sequence under same initial state, so that our research work proves that the nonlinear Boolean function of LILI-128 stream cipher generator is successfully broken.展开更多
利用最小二乘支持向量机(least squares support vector machine,LSSVM)来对GPS在轨卫星钟差数据进行拟合,针对LSSVM拟合钟差两端发散的现象,利用加窗的方法进行抑制。采用IGS提供的精密钟差进行算例分析,发现加窗LSSVM钟差拟合算法比...利用最小二乘支持向量机(least squares support vector machine,LSSVM)来对GPS在轨卫星钟差数据进行拟合,针对LSSVM拟合钟差两端发散的现象,利用加窗的方法进行抑制。采用IGS提供的精密钟差进行算例分析,发现加窗LSSVM钟差拟合算法比现有的钟差拟合算法精度更高,且基于多项式的核函数比较适合加窗LSSVM钟差拟合。展开更多
目的探讨皮层下缺血性脑血管病(sIVD)患者弥散张量成像(DTI)皮层下灰白质微结构变化与整体认知功能和执行功能的独立相关性。方法 66例SIVD患者(其中认知障碍非痴呆组30例,认知功能正常组36例)行常规核磁共振成像(MRI)和DTI检查,采用简...目的探讨皮层下缺血性脑血管病(sIVD)患者弥散张量成像(DTI)皮层下灰白质微结构变化与整体认知功能和执行功能的独立相关性。方法 66例SIVD患者(其中认知障碍非痴呆组30例,认知功能正常组36例)行常规核磁共振成像(MRI)和DTI检查,采用简易精神状态量表(mini-mental state examination,MMSE)和画钟试验(cDT)分别评价其整体认知功能和执行功能。比较两组患者常规MRI上脑形态学指标及皮层下灰白质的DTI参数,分析与SIVD患者认知功能相关的影像学独立相关因素。结果与认知功能正常(NCI)组相比较,认知障碍非痴呆(VCIND)组侧脑室周围白质病变(PVLs)分级显著增加(P<0.01),半卵圆中心看似正常白质(NAWM)区和白质病变(WMLs)区、壳核及丘脑的表观弥散系数(ADC,值显著增加(P<0.01),侧脑室前角NAWM、尾状核、壳核及丘脑的部分各向异性(FA)值显著降低(P<0.05)。控制年龄和受教育程度后,PVLs、半卵圆中心NAWM区和WMLs区ADC值、壳核ADC值与MMSE呈显著负相关(P<0.01);壳核及侧脑室前角NAWM区FA值与MMSE呈显著正相关。脑腔梗数目、侧脑室后角NAWM区及尾状核头部ADC值与CDT呈显著负相关;侧脑室前角NAWM区和丘脑FA值与CDT呈显著正相关。多元逐步回归分析显示半卵圆中心NAWM和WMLs区ADC值与MMSE呈独立负相关;尾状核头ADC值和腔梗数目与CDT呈独立负相关。结论在非痴呆SIVD患者中,半卵圆中心白质结构的完整性是影响SIVD患者整体认知功能的主要因素,且独立于常规MRI上的脑结构改变;尾状核微结构的改变和腔梗的数目是影响SIVD患者执行功能主要因素。展开更多
文摘The nonlinear filter Boolean function of LILI-128 stream cipher generator is studied in this paper. First we measure the complexity of the stream ciphers sequence of LILI-128 stream cipher generator and obtain the shortest bit stream sequence reconstructed Boolean function of nonlinear filter in LILI-128 stream cipher generator. Then the least nonlinear Boolean function of generating stream cipher sequence is reconstructed by clusterig, nonlinear predictive and nonlinear synchronization from shortest bit stream sequence. We have verified the correctness of our reconstruction result by simulating the block diagram of Lili-128 keystream generator using our getting Boolean function and implement designers’ reference module of Lili-128 stream cipher public online, and two methods produce the same synchronous keystream sequence under same initial state, so that our research work proves that the nonlinear Boolean function of LILI-128 stream cipher generator is successfully broken.
文摘利用最小二乘支持向量机(least squares support vector machine,LSSVM)来对GPS在轨卫星钟差数据进行拟合,针对LSSVM拟合钟差两端发散的现象,利用加窗的方法进行抑制。采用IGS提供的精密钟差进行算例分析,发现加窗LSSVM钟差拟合算法比现有的钟差拟合算法精度更高,且基于多项式的核函数比较适合加窗LSSVM钟差拟合。
文摘目的探讨皮层下缺血性脑血管病(sIVD)患者弥散张量成像(DTI)皮层下灰白质微结构变化与整体认知功能和执行功能的独立相关性。方法 66例SIVD患者(其中认知障碍非痴呆组30例,认知功能正常组36例)行常规核磁共振成像(MRI)和DTI检查,采用简易精神状态量表(mini-mental state examination,MMSE)和画钟试验(cDT)分别评价其整体认知功能和执行功能。比较两组患者常规MRI上脑形态学指标及皮层下灰白质的DTI参数,分析与SIVD患者认知功能相关的影像学独立相关因素。结果与认知功能正常(NCI)组相比较,认知障碍非痴呆(VCIND)组侧脑室周围白质病变(PVLs)分级显著增加(P<0.01),半卵圆中心看似正常白质(NAWM)区和白质病变(WMLs)区、壳核及丘脑的表观弥散系数(ADC,值显著增加(P<0.01),侧脑室前角NAWM、尾状核、壳核及丘脑的部分各向异性(FA)值显著降低(P<0.05)。控制年龄和受教育程度后,PVLs、半卵圆中心NAWM区和WMLs区ADC值、壳核ADC值与MMSE呈显著负相关(P<0.01);壳核及侧脑室前角NAWM区FA值与MMSE呈显著正相关。脑腔梗数目、侧脑室后角NAWM区及尾状核头部ADC值与CDT呈显著负相关;侧脑室前角NAWM区和丘脑FA值与CDT呈显著正相关。多元逐步回归分析显示半卵圆中心NAWM和WMLs区ADC值与MMSE呈独立负相关;尾状核头ADC值和腔梗数目与CDT呈独立负相关。结论在非痴呆SIVD患者中,半卵圆中心白质结构的完整性是影响SIVD患者整体认知功能的主要因素,且独立于常规MRI上的脑结构改变;尾状核微结构的改变和腔梗的数目是影响SIVD患者执行功能主要因素。
