分类: 物理学 >> 交叉学科物理及相关领域的科学与技术 提交时间: 2023-09-19
摘要: To accelerate the fractal decoding process, a minimum iterated function system based fast fractal decoding method was proposed in this study. In fractal encoding process, we found that there exists a minimum domain block set (MDBS) which can provide the best-matched domain blocks for all range blocks, and then the domain blocks of MDBS, the range blocks within MDBS, and the associated mapping operations between them constitute the minimum iteration function system (MIFS). In decoding process, MIFS was first recovered in the first iteration. Then, in each of the second to penultimate iterations, only the range blocks within MDBS are reconstructed, and the computations of reconstructing the remaining range blocks can be saved. Finally, all range blocks are reconstructed to obtain the decoded image in the last iteration. Four fractal encoding methods were adopted to assess the performance of the proposed method. Experimental results show that the proposed method can complete the decoding process with fewer computations.
分类: 计算机科学 >> 计算机应用技术 提交时间: 2023-08-25
摘要: To predict fractal decoded image quality more efficiently, an effective decoded image quality prediction method was proposed in this study. In fractal encoding process, the dynamic range of the linear correlation coefficients (LCCs) between range blocks and their best-matched domain blocks was greatly extended by several outliers which increased uncertainty and resulted in reduced prediction accuracy. To remove the interference of outliers, we introduced the effective minimum and maximum of LCCs, which provided the effective bottom and top limits of the actual percentage of accumulated collage error (EBL-APACE and ETL-APACE), respectively. Further, when EBL-APACE reached a large percentage, the average collage error (ACER) can be estimated, and the decoded image quality can be predicted directly.Experimental results show that compared with the previous method, the proposed method can provide higher prediction accuracy with fewer computations.
分类: 计算机科学 >> 计算机应用技术 提交时间: 2023-09-06
摘要: In this study, an adaptively hybrid method was proposed to improve the performance of fractal coding methods. First, we found that the range blocks with large variances (RBLVs) play a crucial role in degrading decoded images, and the effect of the remaining range blocks with small variances (RBSVs) can be ignored. Second, RBLVs were designed to be encoded in an extended domain block pool (EDBP), and the remaining RBSVs were encoded with the no-search fractal encoding method. Moreover, an effective method to adaptively divide the range blocks into the above two categories was proposed. Finally, four fractal coding methods were adopted to assess the performance of the proposed method. Experimental results show that, compared with the previous methods, the proposed method can achieve better-decoded image quality with fewer bits per pixel and fewer computations.
分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: In this paper, model-predictive control (MPC) is proposed for controlling power source of accelerators. The system state equation is employed as the predictive model. With MPC, the difference between possible output and the ideal output is forecasted and decreased, so that the system can trace the ideal trail as closely and quickly as possible. The results of simulations and experiments show that this method can reduce influence of low frequency noise.
分类: 生物学 >> 生物学其他学科 提交时间: 2018-07-18 合作期刊: 《古脊椎动物学报》
摘要: Here we discribe a new ootypes of prismatoolithids found from the Late Cretaceous Jiangjunding Formation in the Laiyang Basin, Shandong Province. On the basis of characters such as elongate ovoids, smooth eggshell surface, relatively thinner eggshell thickness, prismatic eggshell units, slender pores in radial section of eggshell and little pores with round or irregular shapes in tangeital section of eggshell, we erect one new oogenus and one new oospecies: Laiyangoolithus lixiangensis oogen. et oosp. nov. The discovery of L. lixiangensis not only enriches the diversity and composition of the Laiyang Dinosaur Egg Fauna, but the paleogeographic distribution of primatoolithids as well. In addition, it provides more paleontological materials for the study of the diversity and paleogeographic distribution of troodontids in China.
分类: 生物学 >> 动物学 提交时间: 2022-08-02 合作期刊: 《古脊椎动物学报》
摘要: 报道了哈密南湖戈壁首次发现的恐龙蛋,包括长形长形蛋(Elongatoolithus elongatus)和椭圆形蛋未定种(Ovaloolithus oosp.)。这些恐龙蛋的发现不仅扩展了长形蛋类和椭圆形蛋类的古地理分布,而且表明南湖戈壁含蛋岩层地质时代为晚白垩世末期;该地层是否可与吐鲁番盆地的苏巴什组进行对比还有待进一步工作确认
分类: 地球科学 >> 地质学 提交时间: 2017-08-10 合作期刊: 《古脊椎动物学报》
摘要: Here we briefly review the history of research on the Laiyang dinosaur and dinosaur egg faunas, summarize the contributions of C. C. Young and other elder paleontologists to the discoveries of the Late Cretaceous dinosaurs and dinosaur eggs from Laiyang, and introduce the new discoveries and the advances in the research on the Laiyang faunas. The new investigations in Laiyang from 2008 have found a series of valley developed in plain and more than ten new dinosaur or dinosaur egg fossil beds. In 2010, we began the massive excavations at two localities in Jingangkou and collected abundant dinosaurs and other vertebrate fossils, such as a new saurolophine, some theropod material and a new taxon of turtle egg. The bone beds in Locality 2 with the typical sedimentary and burial patterns of mudflow, and these fossil deposits are interpreted as having been carried and deposited by mudflow. The re-observation and the CT scanning data of the crest of Tsintaosaurus spinorhinus (IVPP V 725) show that the crest is fractured and solid. However, based on the re-observations of its cranial and postcranial specimens, we consider that Tsintaosaurus spinorhinus is a valid taxon of lambeosaurines, which have the hollow crest. Therefore, the crest of Tsintaosaurus might not belong to the skull of this individual, and the true form of the crest needs to be confirmed in the future work. We reassess the three species of Tanius, and obtain several results. 1) Tanius sinensis and Tanius chingkankouensis are the valid species of Tanius; 2) Tanius laiyangensis is invalid.; 3) the sacrum and ilium of Tanius chingkankouensis with typical hadrosaurid features should not be referred to Tanius. 简要回顾了莱阳恐龙和恐龙蛋化石群的研究历史和以杨钟健为代表的老一代地质古生物学者对莱阳恐龙和恐龙蛋研究和发现的杰出贡献,并介绍了莱阳恐龙和恐龙蛋的最新发现和若干研究进展。在近年来对莱阳周边地层进行的大规模考察中,发现了一系列发育在平原上的恐龙峡谷群;以及其中蕴含的十几个恐龙和恐龙蛋新地点和新层位。2010年开始,在对莱阳金岗口村附近的2个化石地点的发掘中,发现了以鸭嘴龙科为主的大量脊椎动物化石和蛋化石,包括一类新的栉龙亚科成员,一些大型兽脚类恐龙化石,以及一新的龟鳖类蛋化石等。2号地点化石富集层具有典型的泥石流沉积特征和骨骼埋藏特征。对棘鼻青岛龙的特殊头饰进行了CT扫描和三维重建,发现其头饰是实心结构,但其他骨骼特征证明棘鼻青岛龙属于具有头饰的赖氏龙亚科是确定无疑的,所以目前发现的头饰应不是其真实状态或根本不属于其头部骨骼。此外,对谭氏龙1属3种的重新观察研究得出以下结论:中国谭氏龙和金刚口谭氏龙应是有效属种,但部分骨骼还有疑问,还需要进一步研究,而莱阳谭氏龙为无效属种。
分类: 地球科学 >> 地质学 提交时间: 2018-01-23 合作期刊: 《古脊椎动物学报》
摘要: The first clutch of Stalicoolithus shifengensis is described here. This incomplete dinosaur egg clutch in which three nearly complete eggs and two egg prints were preserved was discovered in the red deposits of the Sanshui Formation at a construction site near the sluice of North Village, Dali Town, Nanhai District, Foshan City, Guangdong Province, China. The eggs in the clutch are stacked with various ranges. Based on the characteristics of the eggshell, these eggs can be assigned to S. shifengensis. The discovery of S. shifengensis in the Sanshui Formation complements the clutch information about the oospecies as well as expands its paleogeographic distribution, and sets the foundation for discussing the diversity of dinosaur eggs in the Sanshui Basin.