171 research outputs found

    Models and Algorithms for Tracking Target with Coordinated Turn Motion

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    Tracking target with coordinated turn (CT) motion is highly dependent on the models and algorithms. First, the widely used models are compared in this paper—coordinated turn (CT) model with known turn rate, augmented coordinated turn (ACT) model with Cartesian velocity, ACT model with polar velocity, CT model using a kinematic constraint, and maneuver centered circular motion model. Then, in the single model tracking framework, the tracking algorithms for the last four models are compared and the suggestions on the choice of models for different practical target tracking problems are given. Finally, in the multiple models (MM) framework, the algorithm based on expectation maximization (EM) algorithm is derived, including both the batch form and the recursive form. Compared with the widely used interacting multiple model (IMM) algorithm, the EM algorithm shows its effectiveness

    Diethyl 4,6-diacetamido­isophthalate

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    In the title compound, C16H20N2O6, two intra­molecular N—H⋯O hydrogen bonds occur, in which the carbonyl O atoms of the ethyl acetate groups serve as the acceptor atoms; both motifs generate S(6) rings. In the crystal, mol­ecules are linked by weak C—H⋯O links (with the acceptor O atoms part of the amide groups), generating [001] chains

    A 550,000-year record of East Asian monsoon rainfall from Be-10 in loess

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    Cosmogenic Be-10 flux from the atmosphere is a proxy for rainfall. Using this proxy, we derived a 550,000-year-long record of East Asian summer monsoon (EASM) rainfall from Chinese loess. This record is forced at orbital precession frequencies, with higher rainfall observed during Northern Hemisphere summer insolation maxima, although this response is damped during cold interstadials. The Be-10 monsoon rainfall proxy is also highly correlated with global ice-volume variations, which differs from Chinese cave delta O-18, which is only weakly correlated. We argue that both EASM intensity and Chinese cave delta O-18 are not governed by high-northern-latitude insolation, as suggested by others, but rather by low-latitude interhemispheric insolation gradients, which may also strongly influence global ice volume via monsoon dynamics

    Research on the Engineering Geological Model and Its Application for Offshore Wind Power Development and Construction

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    [Introduction] Speeding up the offshore wind power construction and development is of great significance to promoting the adjustment of China's energy structure. China is accelerating the process of its wind power development in the entire offshore area, and the geological survey is a vital foundation and key technology of offshore wind power development. [Method] By studying the marine geological survey technologies at home and abroad and combining years of experience in different sea areas, this paper proposed a new technology of engineering geological modeling for offshore wind power development based on the principle of consistency. Firstly, the survey equipment selection and survey line layout started from a three-dimensional initial model to evaluate the impact of geological changes and geohazards on the offshore wind power engineering construction and took into full account the ship selection, field in situ and laboratory tests, and correlation of geophysical prospecting and geotechnical data. Then, with abundant and continuous data obtained from the boreholes and the whole wind farm during the feasibility study and detailed survey, the methods of combination of indoor geotechnical tests with the in-situ tests, the combination of multiple geophysical prospecting devices and the combination of geotechnical and geophysical prospecting methods were used to conduct a consistency analysis of various data, manage the geological survey data platform, update the model and build the final model, and the engineering geological model was continuously optimized and iterated in the subsequent stages. The engineering geological model provided comprehensive engineering geological information for the entire life cycle of offshore wind farm design, installation, operation, maintenance and decommissioning. [Result] The research results and offshore wind power geological survey examples show that by conducting consistent comprehensive layout and data analysis, effectively connecting geotechnical investigation with engineering geophysical prospecting and constructing a three-dimensional crossing engineering geological model, it can effectively solve the problem of "ambiguities of geological survey data" and improve the reliability, accuracy and application of geological survey data. [Conclusion] The new method proposed is one of the effective methods to reduce cost and increase efficiency in offshore engineering as well as the embryonic form of digital twin of offshore wind power geological survey and the foundation for the construction of a geological survey big data base

    Research and Application of Geotechnical Data Consistency in Marine Site Exploration

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    [Introduction] The current marine geological exploration, particularly the geotechnical investigation, often follows traditional experiences without a clear objective, and lacks the evaluations of soil sample disturbance and test results. Therefore, it is necessary to conduct in-depth research on marine geotechnical investigation technology. [Method] Based on the domestic and international research on marine geological exploration technology and multi-year working experience in different sea areas, we developed a new accurate marine geological exploration technology with emphasis on the principle of consistency. The geotechnical investigation part of the new method included two basic aspects: (1) comprehensive evaluation of soil sample disturbance; (2) comprehensive evaluation of consistency of soil strength test results. [Result] The three-dimensional cross-consistency analysis of geotechnical, geophysical, and geological models has established an accurate geological exploration system. Several examples of marine engineering projects showed that the new technology can screen good acquisition methods and data through comprehensive evaluation of clay soil sample disturbance, and conduct consistency analysis of various data by combining the laboratory geotechnical tests with in-situ tests and the routine geotechnical tests with advanced geotechnical tests to obtain richer and more continuous data at the borehole. Compared with the traditional single geotechnical test, our new technology demonstrated the improved reliability and accuracy of the data, and the missing data between the sampling points are compensated. [Conclusion] The proposed new method can reinforce the application of geological exploration data, reduce investigation costs, and provide more geotechnical parameters that are more reliable for marine engineering projects including offshore wind power

    MicroRNA-Mediated Control of Oligodendrocyte Differentiation

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    SummaryMicroRNAs (miRNAs) regulate various biological processes, but evidence for miRNAs that control the differentiation program of specific neural cell types has been elusive. To determine the role of miRNAs in the formation of myelinating oligodendrocytes, we selectively deleted a miRNA-processing enzyme, Dicer1, in oligodendrocyte lineage cells. Mice lacking Dicer1 display severe myelinating deficits despite an expansion of the oligodendrocyte progenitor pool. To search for miRNAs responsible for the induction of oligodendrocyte maturation, we identified miR-219 and miR-338 as oligodendrocyte-specific miRNAs in spinal cord. Overexpression of these miRNAs is sufficient to promote oligodendrocyte differentiation. Additionally, blockage of these miRNA activities in oligodendrocyte precursor culture and knockdown of miR-219 in zebrafish inhibit oligodendrocyte maturation. miR-219 and miR-338 function in part by directly repressing negative regulators of oligodendrocyte differentiation, including transcription factors Sox6 and Hes5. These findings illustrate that miRNAs are important regulators of oligodendrocyte differentiation, providing new targets for myelin repair

    CcGSDMEa functions the pore-formation in cytomembrane and the regulation on the secretion of IL-lβ in common carp (Cyprinus carpio haematopterus)

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    GSDME is the only direct executor of caspase-dependent pyroptosis in both canonical and non-canonical inflammasomes known to date in fish, and plays an important role in anti-bacterial infection and inflammatory response. In order to determine the regulation of GSDMEa on antibacterial infection in innate immune response, the CcGSDMEa gene in common carp (Cyprinus carpio haematopterus) was first identified and characterized, and then its function related to immune defense was investigated. Our results showed that the expressions of CcGSDMEa at the mRNA and protein levels were both significantly increased after Aeromonas hydrophila intraperitoneal infection at the early stage than that in the control group. We found that CcGSDMEa could be cleaved by inflammatory caspase (CcCaspase-1b) and apoptotic caspases (CcCaspase-3a/b and CcCaspase-7a/b). Interestingly, only the CcGSDMEa-NT (1-252 aa) displayed bactericidal activity to Escherichia coli and could punch holes in the membrane of HEK293T cells, whereas CcGSDMEa-FL (1-532 aa) and CcGSDMEa-CT (257-532 aa) showed no above activity and pore-forming ability. Overexpression of CcGSDMEa increased the secretion of CcIL-1β and the release of LDH, and could reduce the A. hydrophila burdens in fish. On the contrary, knockdown of CcGSDMEa reduced the secretion of CcIL-1β and the release of LDH, and could increase the A. hydrophila burdens in fish. Taken together, the elevated expression of CcGSDMEa was a positive immune response to A. hydrophila challenge in fish. CcGSDMEa could perform the pore-formation in cell membrane and the regulation on the secretion of IL-lβ, and further regulate the bacterial clearance in vivo. These results suggested that CcGSDMEa played an important role in immune defense against A. hydrophila and could provide a new insight into understanding the immune mechanism to resist pathogen invasion in teleost

    The 10Be record as a proxy of paleomagnetic reversals and excursions: A Mediterranean perspective

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    The 10Be/9Be ratio is acknowledged as an effective tool for establishing the stratigraphic position of paleomagnetic excursions. Still, our data suggest that, in particular depositional settings, the interplay between climate, sedimentation and oceanography may jeopardize a realistic depiction of the natural 10Be/9Be record

    Coupling Efficiency Measurements for Long-pulsed Solid Sodium Laser Based on Measured Sodium Profile Data

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    In 2013, a serial sky test has been held on 1.8 meter telescope in Yunnan observation site after 2011-2012 Laser guide star photon return test. In this test, the long-pulsed sodium laser and the launch telescope have been upgraded, a smaller and brighter beacon has been observed. During the test, a sodium column density lidar and atmospheric coherence length measurement equipment were working at the same time. The coupling efficiency test result with the sky test layout, data processing, sodium beacon spot size analysis, sodium profile data will be presented in this paper
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