Douglas-Peucker-Based Accelerated Similarity Measures for Massive AIS Trajectories

Kai WANG,Ryan Wen LIU,Yan LI,Maohan LIANG,Yi LIU,Jianhua WU,Jingxian LIU 국제이네비해양경제학회 2017 International Journal of e-Navigation and Maritime Vol.8 No.1

With the rapid development of the global economy, transport safety and security have become the key issues in maritime transportation all over the world. In practical applications, the Automatic Identification System (AIS)-based measurement of similarities between different vessel trajectories plays an important role in improving maritime transportation, e.g., maritime navigation, maritime supervision and management. However, the received AIS datasets are usually composed of a large amount of redundant information which could significantly increase the computational complexity. To deal with this problem, a Douglas-Peucker (DP)-based calculation method is introduced in this paper to accurately compress the spatio-temporal AIS trajectories while preserving the main geometrical structures. Based on the compressed trajectories, it is able to accelerate the Dynamic Time Warping (DTW) algorithm for the measurement of similarities between different vessel trajectories. In particular, the combination of DP and DTW has the capacity of significantly reducing the computational cost and guaranteeing the accuracy of similarity measures. The experimental results have demonstrated the superior performance of the proposed method in terms of computational cost and accuracy of similarity measures.

Experimental and Numerical Study on the Nonlinear Behavior of Strengthened Beams Under High Preload

Jingxian Zhao,Hongbo Liu,Zhihua Chen,Shishuo Zhang 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.5

The behavior of the H-beam strengthened with welded T-beam is tested and simulated to investigate the nonlinear behavior of fl exural members strengthened under high preload. Experimental result reveals that for the four specimens that fails predominantly by fl exural yielding, the increase in the preload results in a reduction in both the yield load and the ultimate load when the preload ratio exceeds 0.75. In the parametric numerical analysis, the eff ect of heat input is considered by means of indirect thermal-structural coupling analysis. At each preload ratio, the infl uence of the aspect ratio, which is defi ned as the ratio between section height and width, is studied. Results show that as the aspect ratio decreases, the discrepancy between the ultimate load of preloaded and unpreloaded beams increases. An empirical formula is proposed to calculate the reduction of ultimate load for beams aff ected from diff erent preload ratios considering various aspect ratios. Further studies are conducted on the welding safety. It is demonstrated that beam with the section larger than WH100 × 100 × 10 × 10 may be welded under high load safely when the preload ratio is < 0.97. What’s more, the approaches to calculate residual defl ection and increments of defl ection during welding process are proposed and verifi ed to be eff ective. Finally, the proposed theoretical method to calculate design bearing capacity of reinforced beams may be utilized to increase the accuracy of design process.

Structural analysis and testing of a miniature flexible joint under pressure and vector loading

Junxue Ren,Xiaoguang Zhang,Jingxian Yang,Chao Wang,Yu Liu,Wei Yang 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.9

The structural characteristics of a miniature tactical motor flexible joint subjected to pressure and vector loading were investigated usingfinite element analysis and bench test. Three-dimensional non-linear finite element analysis was conducted using ANSYS Code Version11.0. The axial deflection, vectoring torque, and stress distributions in elastomeric and reinforcement rings were presented. Thepredicted values were consistent with the test data. Results indicate that the axial compressive stiffness increased gradually and nonlinearlywith pressure, while the angular stiffness remained nearly constant in the vectoring angle range from 0° to 6°. Under pressureloading, the elastomeric shear stress was negative, high at both sides, and low at the center of the cross-section, while the reinforcementhoop stress was compressive at the inner radius and tensile at the outer radius. The compressive stress was also high. The flexible jointexhibited higher stress level with altered stress distribution when subjected to additional vector loading. Existing empirical formulas forreinforcement hoop compressive stress were determined to be not applicable to the miniature flexible joint, which significantly overestimatedthe stress caused by pressure and underestimated the stress caused by vectoring.

滿語 복수에 대하여

John H. Koo(具璋會),Liu Jingxian,Zhao Aping,Wu Baozhu,Kwon Oh-sun 비교민속학회 1993 비교민속학 Vol.10 No.-

In the present study, we re-exame the plural for mation in Manchu, and attempt to describe more precisely the conditions under which various plural morphemes are used, using data drawn from resources of written and spoken Manchu. In the past, the research on this subject has been rather superficial, lacking sufficient documental support, particularly phonological interpretation. We argue that the plural formation is closely related to the vowel harmony in Manchu and to other non-linguistic factors as in some other Tungus-Manchu languages(eㆍgㆍ, Solon). The study concludes that the plural in Manchu cannot be adequately accounted for by linguistic analysis alone. It suggests that some cultural factors in the traditional Manchu society play a significant role in for ming the variety of plural forms.

Structural Characterization of Microwave-Assisted Solution-Synthesized Strontium-Substituted Hydroxyapatite

Jianguo Liao,Yanqun Li,Xiali Guan,Jingxian Liu,Yongxiang Zhang,Yufen Xie,Zhengpeng Yang,Xingze Duan,Aiguo Zhou,Jiangnan Zhu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.10

Hydroxyapatite and strontium-substituted hydroxyapatite nanoparticles (n-HA and Sr-HA) were prepared by microwave-assisted solution synthesis with aqueous solutions of various Sr/(Sr+Ca) molar ratios ranging from 0% to 15%. The structural properties of the hydroxyapatite powders were investigated by X-ray powder diffraction, Fourier transform infrared spectroscopy and Raman spectra, field emission scanning electron microscopy coupled with energy dispersive X-ray spectrometry and transmission electron microscopy. The results confirmed that strontium ions had been incorporated into the hydroxyapatite lattice. The synthetic n-HA and Sr-HA nanocrystalline consisted of hydroxyapatite crystalline phase with hexagonal structure, and the particle size was 30–40 x 60–70 nm and 40–50 x 70–80 nm, respectively. The calcined HA particle size ranged from about 120 nm to 150 nm, the calcined Sr-HA products were composed of spherical aggregates with a size of about 70–100 nm. The incorporation of Sr ions lead to the formation of vacancies in the crystal structure of the HA. The results indicated that the strontium substitution did not change the crystal structures. More Sr resulted in less calcined crystallites and formed agglomerates owing to the size effect.

LincR-PPP2R5C Promotes Th2 Cell Differentiation Through PPP2R5C/PP2A by Forming an RNA–DNA Triplex in Allergic Asthma

Ji Ningfei,Chen Zhongqi,Wang Zhengxia,Sun Wei,Yuan Qi,Zhang Xijie,Jia Xinyu,Wu Jingjing,Jiang Jingxian,Song Meijuan,Xu Tingting,Liu Yanan,Ma Qiyun,Sun Zhixiao,Bao Yanmin,Zhang Mingshun,Huang Mao 대한천식알레르기학회 2024 Allergy, Asthma & Immunology Research Vol.16 No.1

Purpose: The roles and mechanisms of long noncoding RNAs (lncRNAs) in T helper 2 (Th2) differentiation from allergic asthma are poorly understood. We aimed to explore a novel lncRNA, LincR-protein phosphatase 2 regulatory subunit B' gamma (PPP2R5C), in Th2 differentiation in a mouse model of asthma. Methods: LincR-PPP2R5C from RNA-seq data of CD4+ T cells of asthma-like mice were validated and confirmed by quantitative reverse transcription polymerase chain reaction, northern blotting, nuclear and cytoplasmic separation, and fluorescence in situ hybridization (FISH). Lentiviruses encoding LincR-PPP2R5C or shRNA were used to overexpress or silence LincR-PPP2R5C in CD4+ T cells. The interactions between LincR-PPP2R5C and PPP2R5C were explored with western blotting, chromatin isolation by RNA purification assay, and fluorescence resonance energy transfer. An ovalbumin-induced acute asthma model in knockout (KO) mice (LincR-PPP2R5C KO, CD4 conditional LincR-PPP2R5C KO) was established to explore the roles of LincR-PPP2R5C in Th2 differentiation. Results: LncR-PPP2R5C was significantly higher in CD4+ T cells from asthmatic mice ex vivo and Th2 cells in vitro. The lentivirus encoding LincR-PPP2R5C suppressed Th1 differentiation; in contrast, the short hairpin RNA (shRNA) lentivirus decreased LincR-PPP2R5C and Th2 differentiation. Mechanistically, LincR-PPP2R5C deficiency suppressed the phosphatase activity of the protein phosphatase 2A (PP2A) holocomplex, resulting in a decline in Th2 differentiation. The formation of an RNA-DNA triplex between LincR-PPP2R5C and the PPP2R5C promoter enhanced PPP2R5C expression and activated PP2A. LincR-PPP2R5C KO and CD4 conditional KO decreased Th2 differentiation, airway hyperresponsiveness and inflammatory responses. Conclusions: LincR-PPP2R5C regulated PPP2R5C expression and PP2A activity by forming an RNA-DNA triplex with the PPP2R5C promoter, leading to Th2 polarization in a mouse model of acute asthma. Our data presented the first definitive evidence of lncRNAs in the regulation of Th2 cells in asthma.