Airborne navigation database(NavDB)coding directly affects the result of analysis on the instrument flight procedure by the modern aircraft flight management computer(FMC).A reasonable flight track transition mode can...Airborne navigation database(NavDB)coding directly affects the result of analysis on the instrument flight procedure by the modern aircraft flight management computer(FMC).A reasonable flight track transition mode can improve the track tracking accuracy and flight quality of the aircraft.According to the path terminator(PT)and track transition characteristics of the performance based navigation(PBN)instrument flight procedure and by use of the world geodetic system(WGS)-84 ellipsoidal coordinate system,the algorithms for“fly by”and“fly over”track transition connections are developed,together with the algorithms for coordinates of fix-to-altitude(FA)altitude termination point and heading-to-an-intercept(VI)track entry point and for track transition display of the navigation display(ND).According to the simulation carried out based on the PBN instrument approach procedure coding of a certain airport and the PBN route data at a high altitude,the algorithm results are consistent with the FMC-calculated results and the actual ND results.展开更多
This paper focused on the integration of case base and relational database management system (RDBMS). The organizational and commercial impact will be far greater if the case based reasoning (CBR) system is integrated...This paper focused on the integration of case base and relational database management system (RDBMS). The organizational and commercial impact will be far greater if the case based reasoning (CBR) system is integrated with main stream information system, which is exemplified by RDBMS. The scalability, security and robustness provided by a commercial RDBMS facilitate the CBR system to manage the case base. The virtual table in relational database (RDB) is important for CBR systems to implement the flexibility of case template. It was discussed how to implement a flexible and succinct case template, and a mapping model between case template and RDB was proposed. The key idea is to build the case as the virtual view of underlying data.展开更多
Mitochondrial DNA sequences of the entire control region and three coding regions were analyzed in 108 unrelated individuals from three regions of Bangladesh. Sequence evaluation was performed with validated primers a...Mitochondrial DNA sequences of the entire control region and three coding regions were analyzed in 108 unrelated individuals from three regions of Bangladesh. Sequence evaluation was performed with validated primers and combined sequence comparison led to the identification of 14 different haplotypes characterized by 37 variable polymorphic sites. The Bangladeshi sequences exhibited high variations and low random match probability, indicating for forensic application. The mean pairwise difference between individual was 9.698 ± 1.8658 nucleotides (95% CI 9.67 - 9.69), compared to a mean pairwise difference of 9.890 ± 4.189 nucleotides reported from Northeast Asia and suggested significant differences in the mtDNA composition of the various populations. The sequence diversity of 108 Bangladeshi Bengali samples (n = 216 chromosomes) was estimated to be 0.8475 ± 0.13406. This study first time reports that the comparison of closely related mtDNA sequences can be very useful for improving mtDNA database quality, as well as provide haplotype information for forensic study in mainstream population of Bangladesh.展开更多
科技行业的快速发展带来信息量的暴增,各行各业都需要收集和应用大量的数据,海量数据在发挥价值的同时,给数据安全领域带来了史无前例的挑战。关系型数据库作为数据的底层存储载体之一,其存储的数据规模大、数据内容丰富、数据隐私度高...科技行业的快速发展带来信息量的暴增,各行各业都需要收集和应用大量的数据,海量数据在发挥价值的同时,给数据安全领域带来了史无前例的挑战。关系型数据库作为数据的底层存储载体之一,其存储的数据规模大、数据内容丰富、数据隐私度高。数据库的数据一旦泄露将会造成巨大的损失,保护数据库的所有权,确认数据的归属刻不容缓。对于现有的数据库水印技术来说,提高水印嵌入容量和减小数据失真之间存在固有矛盾问题,为了缓解此问题且进一步提高水印的鲁棒性,提出了一种基于动态差分扩展的强鲁棒数据库水印算法。该算法选取QR码作为水印,利用经过Haar小波变换的图像低频部分进行奇异值分解(SVD,singular value decomposition),提取部分特征值,用取余后的特征值作为待嵌入的水印序列,使得相同长度的水印序列包含更多信息,缩短了嵌入水印的长度。该算法结合自适应差分进化算法和最小差值算法选择最佳嵌入属性位,以缓解传统差分扩展技术在嵌入水印时计算效率低、数据失真大、鲁棒性差的问题,提高水印嵌入容量的同时减少了数据的失真。实验结果表明,该算法保证高水印嵌入率的同时数据失真较低,能够抵御多种攻击,具有良好的鲁棒性,追踪溯源的能力强,且与现有的算法对比优势明显,在数据安全领域具有广阔的应用前景。展开更多
基金supported by the National Natural Science Foundation of China(u2133209)。
文摘Airborne navigation database(NavDB)coding directly affects the result of analysis on the instrument flight procedure by the modern aircraft flight management computer(FMC).A reasonable flight track transition mode can improve the track tracking accuracy and flight quality of the aircraft.According to the path terminator(PT)and track transition characteristics of the performance based navigation(PBN)instrument flight procedure and by use of the world geodetic system(WGS)-84 ellipsoidal coordinate system,the algorithms for“fly by”and“fly over”track transition connections are developed,together with the algorithms for coordinates of fix-to-altitude(FA)altitude termination point and heading-to-an-intercept(VI)track entry point and for track transition display of the navigation display(ND).According to the simulation carried out based on the PBN instrument approach procedure coding of a certain airport and the PBN route data at a high altitude,the algorithm results are consistent with the FMC-calculated results and the actual ND results.
文摘This paper focused on the integration of case base and relational database management system (RDBMS). The organizational and commercial impact will be far greater if the case based reasoning (CBR) system is integrated with main stream information system, which is exemplified by RDBMS. The scalability, security and robustness provided by a commercial RDBMS facilitate the CBR system to manage the case base. The virtual table in relational database (RDB) is important for CBR systems to implement the flexibility of case template. It was discussed how to implement a flexible and succinct case template, and a mapping model between case template and RDB was proposed. The key idea is to build the case as the virtual view of underlying data.
文摘Mitochondrial DNA sequences of the entire control region and three coding regions were analyzed in 108 unrelated individuals from three regions of Bangladesh. Sequence evaluation was performed with validated primers and combined sequence comparison led to the identification of 14 different haplotypes characterized by 37 variable polymorphic sites. The Bangladeshi sequences exhibited high variations and low random match probability, indicating for forensic application. The mean pairwise difference between individual was 9.698 ± 1.8658 nucleotides (95% CI 9.67 - 9.69), compared to a mean pairwise difference of 9.890 ± 4.189 nucleotides reported from Northeast Asia and suggested significant differences in the mtDNA composition of the various populations. The sequence diversity of 108 Bangladeshi Bengali samples (n = 216 chromosomes) was estimated to be 0.8475 ± 0.13406. This study first time reports that the comparison of closely related mtDNA sequences can be very useful for improving mtDNA database quality, as well as provide haplotype information for forensic study in mainstream population of Bangladesh.
文摘科技行业的快速发展带来信息量的暴增,各行各业都需要收集和应用大量的数据,海量数据在发挥价值的同时,给数据安全领域带来了史无前例的挑战。关系型数据库作为数据的底层存储载体之一,其存储的数据规模大、数据内容丰富、数据隐私度高。数据库的数据一旦泄露将会造成巨大的损失,保护数据库的所有权,确认数据的归属刻不容缓。对于现有的数据库水印技术来说,提高水印嵌入容量和减小数据失真之间存在固有矛盾问题,为了缓解此问题且进一步提高水印的鲁棒性,提出了一种基于动态差分扩展的强鲁棒数据库水印算法。该算法选取QR码作为水印,利用经过Haar小波变换的图像低频部分进行奇异值分解(SVD,singular value decomposition),提取部分特征值,用取余后的特征值作为待嵌入的水印序列,使得相同长度的水印序列包含更多信息,缩短了嵌入水印的长度。该算法结合自适应差分进化算法和最小差值算法选择最佳嵌入属性位,以缓解传统差分扩展技术在嵌入水印时计算效率低、数据失真大、鲁棒性差的问题,提高水印嵌入容量的同时减少了数据的失真。实验结果表明,该算法保证高水印嵌入率的同时数据失真较低,能够抵御多种攻击,具有良好的鲁棒性,追踪溯源的能力强,且与现有的算法对比优势明显,在数据安全领域具有广阔的应用前景。
