Aiming at the potential presence of mixing automatic identification system(AIS) signals,a new demodulation scheme was proposed for separating other interfering signals in satellite systems.The combined iterative cross...Aiming at the potential presence of mixing automatic identification system(AIS) signals,a new demodulation scheme was proposed for separating other interfering signals in satellite systems.The combined iterative cross-correlation demodulation scheme,referred to as CICCD,yielded a set of single short signals based on the prior information of AIS,after the frequency,code rate and modulation index were estimated.It demodulates the corresponding short codes according to the maximum peak of cross-correlation,which is simple and easy to implement.Numerical simulations show that the bit error rate of proposed algorithm improves by about 40% compared with existing ones,and about 3 dB beyond the standard AIS receiver.In addition,the proposed demodulation scheme shows the satisfying performance and engineering value in mixing AIS environment and can also perform well in low signal-to-noise conditions.展开更多
Tag key encapsulation mechanism （Tag-KEM）/data encapsulation mechanism （DEM） is a hybrid framework proposed in 2005. Tag-t（EM is one of its parts by using public-key encryption （PKE） technique to encapsulate a ...Tag key encapsulation mechanism （Tag-KEM）/data encapsulation mechanism （DEM） is a hybrid framework proposed in 2005. Tag-t（EM is one of its parts by using public-key encryption （PKE） technique to encapsulate a symmetric key. In hybrid encryptions, the long-raessage PKE is not desired due to its slow operation. A general method is presented for constructing Tag-KEM schemes with short-message PKEs. The chosen ciphertext security is proved in the random oracle model. In the method, the treatment of the tag part brings no additional ciphertext redundancy. Among all the methods for constructing Tag-KEM, the method is the first one without any validity checking on the tag part, thus showing that the Tag-KEM/DEM framework is superior to KEM＋DEM one.展开更多
An analytical model for the propagation of combined stress waves in a functionally graded thin-walled tube subjected to combined longitudinal and torsional impact loading is established.The material properties of the ...An analytical model for the propagation of combined stress waves in a functionally graded thin-walled tube subjected to combined longitudinal and torsional impact loading is established.The material properties of the tube are assumed to be continuously graded along the length according to a power law function with respect to the volume fractions of the constituents.The generalized characteristic theory is used to analyze the main features of the characteristic wave speeds and simple wave solutions in the functionally graded thin-walled tube.The finite difference method is used to discretize the governing equations.Two types of typical solutions are obtained for the functionally graded tube and the homogeneous tube subjected to combined longitudinal and torsional step loading.The numerical results reveal some abnormal phenomena in the stress path and wave process of the functionally graded thin-walled tube.展开更多
Investigated the properties of LUCas sequence(LUC), the paper proposed a new variant of (probabilistic) public-key encryption scheme. Security analysis of the proposed encryption schemes shows that its one-wayness is ...Investigated the properties of LUCas sequence(LUC), the paper proposed a new variant of (probabilistic) public-key encryption scheme. Security analysis of the proposed encryption schemes shows that its one-wayness is equivalent to partial LUC discrete logarithm problem in ZN, and for the proposed probabilistic encryption scheme, its semantic security is equivalent to decisional LUC Diffie-Hellman problem in ZN. At last, the efficiency of the proposed schemes is briefly analyzed.展开更多
为合理地解决环境敏感区铁路线路方案综合优选问题,研究顾及环境敏感特征的铁路线路方案优选方法 .首先,基于文献调研和环境敏感区特征探析,分析总结影响线路方案的因素,构建涵盖4大方面18项指标的顾及环境敏感特征的铁路线路方案优选...为合理地解决环境敏感区铁路线路方案综合优选问题,研究顾及环境敏感特征的铁路线路方案优选方法 .首先,基于文献调研和环境敏感区特征探析,分析总结影响线路方案的因素,构建涵盖4大方面18项指标的顾及环境敏感特征的铁路线路方案优选指标体系.其次,在专家经验主观赋权和工程信息客观赋权的基础上,运用灰色关联分析理论进行组合赋权.然后,结合改进优劣解距离法(Technique for Order Preference by Similarity to an Ideal Solution, TOPSIS)确定各线路方案的相对贴近度,进而实现线路方案优选.最后,以新建铁路西宁至成都线合作至郎木寺段线路方案选择为例进行优选方法验证.研究结果表明:该区段线路的4个备选方案的相对贴近度依次为0.527 9,0.523 6,0.508 7,0.522 7,方案一的相对贴近度最大为最优方案,基于本方法的优选结果与实际专家论证结果一致;与传统TOPSIS比较,基于改进TOPSIS的运算结果避免了计算结果受单方面优势指标影响的弊端,在运算过程中将线路方案涉及的极端优劣指标进行综合权衡考量,得到的运算结果更贴近实际情况.研究成果可为未来环境敏感区线路方案优选问题提供一种新的优选思路.展开更多
基金Project(9140C860304) supported by the National Defense Key Laboratory Foundation of China
文摘Aiming at the potential presence of mixing automatic identification system(AIS) signals,a new demodulation scheme was proposed for separating other interfering signals in satellite systems.The combined iterative cross-correlation demodulation scheme,referred to as CICCD,yielded a set of single short signals based on the prior information of AIS,after the frequency,code rate and modulation index were estimated.It demodulates the corresponding short codes according to the maximum peak of cross-correlation,which is simple and easy to implement.Numerical simulations show that the bit error rate of proposed algorithm improves by about 40% compared with existing ones,and about 3 dB beyond the standard AIS receiver.In addition,the proposed demodulation scheme shows the satisfying performance and engineering value in mixing AIS environment and can also perform well in low signal-to-noise conditions.
基金Supported by the National Natural Science Foundation of China(60603010,60970120)~~
文摘Tag key encapsulation mechanism （Tag-KEM）/data encapsulation mechanism （DEM） is a hybrid framework proposed in 2005. Tag-t（EM is one of its parts by using public-key encryption （PKE） technique to encapsulate a symmetric key. In hybrid encryptions, the long-raessage PKE is not desired due to its slow operation. A general method is presented for constructing Tag-KEM schemes with short-message PKEs. The chosen ciphertext security is proved in the random oracle model. In the method, the treatment of the tag part brings no additional ciphertext redundancy. Among all the methods for constructing Tag-KEM, the method is the first one without any validity checking on the tag part, thus showing that the Tag-KEM/DEM framework is superior to KEM＋DEM one.
文摘An analytical model for the propagation of combined stress waves in a functionally graded thin-walled tube subjected to combined longitudinal and torsional impact loading is established.The material properties of the tube are assumed to be continuously graded along the length according to a power law function with respect to the volume fractions of the constituents.The generalized characteristic theory is used to analyze the main features of the characteristic wave speeds and simple wave solutions in the functionally graded thin-walled tube.The finite difference method is used to discretize the governing equations.Two types of typical solutions are obtained for the functionally graded tube and the homogeneous tube subjected to combined longitudinal and torsional step loading.The numerical results reveal some abnormal phenomena in the stress path and wave process of the functionally graded thin-walled tube.
基金Supported by the 973 State Key Project of China (No.G1999035803)the National Natural Science Foundation of China (No.69931010).
文摘Investigated the properties of LUCas sequence(LUC), the paper proposed a new variant of (probabilistic) public-key encryption scheme. Security analysis of the proposed encryption schemes shows that its one-wayness is equivalent to partial LUC discrete logarithm problem in ZN, and for the proposed probabilistic encryption scheme, its semantic security is equivalent to decisional LUC Diffie-Hellman problem in ZN. At last, the efficiency of the proposed schemes is briefly analyzed.
文摘为合理地解决环境敏感区铁路线路方案综合优选问题,研究顾及环境敏感特征的铁路线路方案优选方法 .首先,基于文献调研和环境敏感区特征探析,分析总结影响线路方案的因素,构建涵盖4大方面18项指标的顾及环境敏感特征的铁路线路方案优选指标体系.其次,在专家经验主观赋权和工程信息客观赋权的基础上,运用灰色关联分析理论进行组合赋权.然后,结合改进优劣解距离法(Technique for Order Preference by Similarity to an Ideal Solution, TOPSIS)确定各线路方案的相对贴近度,进而实现线路方案优选.最后,以新建铁路西宁至成都线合作至郎木寺段线路方案选择为例进行优选方法验证.研究结果表明:该区段线路的4个备选方案的相对贴近度依次为0.527 9,0.523 6,0.508 7,0.522 7,方案一的相对贴近度最大为最优方案,基于本方法的优选结果与实际专家论证结果一致;与传统TOPSIS比较,基于改进TOPSIS的运算结果避免了计算结果受单方面优势指标影响的弊端,在运算过程中将线路方案涉及的极端优劣指标进行综合权衡考量,得到的运算结果更贴近实际情况.研究成果可为未来环境敏感区线路方案优选问题提供一种新的优选思路.
