ADAMTS18 has been identified as an orphan member of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family of Zn-dependent secreted metalloproteinases since 2002. Despite ...the recent breakthroughs in tumor biology of ADAMTS18, there is no literature systematically discussing the relationship between ADAMTS18 and cancer. In this review, we will summarize the expression pattern and prognostic value of ADAMTS18 in various cancers. In addition, we will highlight the biological functions of ADAMTS18 in the tumor microenvironment, including the regulation of cell proliferation signals, death patterns, invasion, and migration, which influence cancer progression.
Due to the low signal power, the Global Navigation Satellite System (GNSS) signal is vulnerable to interference and even cannot be captured or tracked in harsh environments. As an alternative, the ...Low Earth Orbit (LEO) satellite has been widely used in the navigation field due to the advantages of low cost and strong signals. It is becoming a significant component of the new combined navigation system with GNSS. The combination of an LEO Doppler signal and GNSS observables can improve the positioning accuracy and high-precision positioning convergence time of the GNSS receiver. However, the GNSS signal receiving capability cannot be improved from this data fusion level. We propose a novel assisted structure where GNSS signal acquisition and Doppler tracking are assisted by LEO Doppler positioning. The receiver uses the LEO signal to achieve Doppler positioning firstly. Then, the coarse position with the GNSS navigation messages received from LEO, as well as the estimated clock information, is used to assist in the acquisition and tracking of GNSS. In this way, the GNSS receiver's sensitivity can get the benefit from this integrated system. The paper presents the structure of the assisted receiver and analyzes the assisted GNSS signal acquisition and carrier tracking performance in detail. Simulation experiments of this assisted structure are carried out to verify its superiority of acquisition and tracking sensitivity in comparison with standalone GNSS receivers. Theoretical analysis and experimental results show that the proposed acquisition method can achieve 90% detection probability at a carrier-to-noise ratio (C/N
) of 15 dB-Hz, which is about 8 dB higher than the conventional acquisition method without assistance; the proposed tracking method can track weak signals of
dB-Hz, which is about 4 dB higher than the conventional method. Therefore, this novel LEO-assisted receiver has significantly improved weak signal acquisition and tracking sensitivity.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
AbstractDrought is a disaster that seriously constrains economic development and endangers human life. This paper explores the potential of Global Navigation Satellite System Reflectometry (GNSS-R) ...for drought monitoring, using Cyclone Global Navigation Satellite System (CYGNSS) data to monitor drought in Jiangxi and Hunan Provinces, China, in 2022. This study applies the Random Under-sampling Boosting (RUSBoost) algorithm to detect waterbodies and linear regression to retrieve soil moisture (SM). Result shows that drought in September was heaviest, with the area of Poyang Lake in Jiangxi and Dongting Lake in Hunan decreasing by 70.2% and 76.9%, respectively, compared to that in June. The variation in retrieved SM shows that the Poyang Lake Plain and Jitai Basin in Jiangxi and the Dongting Lake, Yuanjiang River, and Xiangjiang River basins in Hunan suffered from the most serious drought. The variation in retrievals shows high consistency with various reference datasets, including Soil Moisture Active Passive (SMAP) SM data and vegetation condition index (VCI). The correlation coefficient between retrieved SM and VCI is 0.93 in Jiangxi and 0.94 in Hunan.
Communication, positioning, navigation, and decision-making abilities have evolved into Positioning, Navigation, and Timing (PNT) intelligence during the long process of human migration and hence ...promoted human evolution. This article defines intelligence and smartness from the perspective of biological intelligence. New requirements as a result of the development of communication, navigation, time service, and decision making are identified in this study. The article points out that there are many radio PNT service methods, such as 5G, the new-generation high-speed communication networks and the low-latency and ubiquitous mobile communication networks as well as Global Navigation Satellite System (GNSS), but the integrated application is especially important in providing technical support for the adjustment and control of the physical world by intelligent sensing, cognition, decision-making, and precise coordination. The fusion of 5G and GNSS including BeiDou Navigation Satellite System (BDS) information with the corresponding equipment can be embedded into a machine to make it intelligent. Furthermore, the fused information of 5G and GNSS together with the environment information may extend human perception and physical world control ability in terms of time and space scale. It will help to develop critical information infrastructure in the age of intelligence, which will also extend the definition of artificial intelligence. Additionally, the “5G + BDS/GNSS” fusion path is analyzed explicitly herein in terms of realization methods, information processing, and new application services. On the whole, the application of “5G + BDS/GNSS + satellite-based communication” as a critical infrastructure for land, sea, air, space and network spatiotemporal control rights is proposed.
In real-time precise point positioning (RT-PPP), PPP one-way timing is used to steer local oscillators, but the timing performance could be significantly affected by the datum stability of the ...satellite clock product. To measure the stability of a satellite clock datum relative to the hydrogen maser (H-MASER) clock, a new GNSS satellite clock datum stability assessing model based on the overlapping Allan variance (AVAR) is proposed for both PPP one-way timing and time synchronization. Experiments were carried out with nine Global Navigation Satellite System (GNSS) stations at time laboratories with an external H-MASER clock to analyze the datum stability performance. In the experiments, RT satellite products from five RT Analysis Centers (ACs): CNES, ESA, GFZ, GMV, WHU, and the final satellite product from IGS were used in the comparison. Results show that the datum stability of all RT products tended to be similar, i.e., 6 to 8E−15/day, where WHU and GMV outperformed other RT ACs. Moreover, these datum stability results indicate that RT-PPP for steering local oscillators improves stability to 6 to 8E−15/day when selected with an appropriate RT product. The estimation noise in all RT ACs was at about the same level, i.e., 1 to 2E−15/day, but WHU delivered the most stable performance. Thus, datum stability is an effective guide for setting parameters and making long-term stability predictions when steering local oscillators, and satellite clock datum stability can be measured conveniently and quickly using the GNSS satellite clock datum stability assessing model proposed in this paper.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
With the rapid development of the Internet, the security of network equipment has received extensive attention.Aiming at the problems of that the existing network equipment anomaly detection ...technology is destructive and difficult to detect, the paper uses the packets delay spent by the network equipment to transmit and process data packets as the detection basis, and proposes an anomaly detection scheme based on delay characteristics.The proposed scheme adopts side channel analysis, and it does not need to upgrade the equipment's software or hardware.It has the characteristics of non-intrusive and easy to implement.Firstly, the method uses the high-precision timing technology time stamp machine to collect the time delay information, and uses the genetic algorithm to extract the peak position feature of the delay distribution.Secondly, to solve the problem of the imbalance of data set, the method uses one-class support vector machine algorithm to construct anomaly detection algorithm.Finally, the validity of
This paper designs a cascading vector tracking loop based on the Unscented Kalman Filter (UKF) for high dynamic environment. Constant improvement in dynamic performance is an enormous challenge to ...the traditional receiver. Due to the doppler effect, the satellite signals received by these vehicles contain fast changing doppler frequency shifts and the first and second derivatives of doppler frequency, which will directly cause a negative impact on the receiver’s stable tracking of the signals. In order to guarantee the dynamic performance and the tracking accuracy, this paper designs a vector carrier structure to estimate the doppler component of a signal. Firstly, after the coherence integral, the IQ values are reorganized into new observations. Secondly, the phase error and frequency of the carrier are estimated through the pre-filter. Then, the pseudorange and carrier frequency are used as the observations of the main filter to estimate the motion state of the aircraft. Finally, the current state is fed back to the carrier Numerical Controlled Oscillator (NCO) as a complete closed loop. In the whole structure, the cascading vector loop replaces the original carrier tracking loop, and the stable signal tracking of code loop is guaranteed by carrier assisted pseudo-code method. In this paper, with the high dynamic signals generated by the GNSS signal simulator, this designed algorithm is validated by a software receiver. The results show that this loop has a wider dynamic tracking range and lower tracking error than the second-order frequency locked loop assisted third-order phase locked loop in high dynamic circumstances. When the acceleration of carrier is 100 g, the convergence time of vector structure is about 100 ms, and the carrier phase error is lower than 0.6 mm.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
One major source of uncertainties in the estimation of soil organic carbon (SOC) dynamics is carbon (C) residence time, an important parameter in terrestrial ecosystem C cycling models. To better ...predict terrestrial dynamics, C residence time and its controlling factors need to be well quantified and investigated. In this study, we applied a data assimilation approach to quantify the residence times of different soil C pools on the Tibetan Plateau, based on incubated soil carbon dioxide (CO2) efflux data. We also assessed the effects of soil properties on C residence times. Our results showed that the residence times of active (RTA) and slow (RTS) C pools were well estimated through data assimilation. Soil physical, chemical, and microbial properties significantly regulated RTA and RTS. The RTA was higher in soils with high clay contents (R2 = 0.52, p < 0.01) and low microbial quotients (qMB) (R2 = 0.55, p < 0.01), whereas, the RTS was higher in soils with high clay contents (R2 = 0.76, p < 0.01), high C:N ratios (R2 = 0.44, p < 0.05), low qMBvalues (R2 = 0.50, p < 0.05), and low soil pH values (R2 = 0.80, p < 0.01). Structural equation modeling (SEM) analyses indicated that the model could explain 55% and 91% of the variations in the RTA and RTS, respectively. The qMB was the key factor in regulating the RTA, while soil pH was the crucial variable in controlling the RTS. These results demonstrated that the major controlling factors on the RTA and RTS were different. Considering these variables and their different controls on residence times of different soil C pools could provide more accurate estimation of terrestrial C cycles, and prediction of future C-climate feedbacks.
•We assessed the effects of soil properties on the different C pools residence times.•Microbial quotient was the key factor in regulating the active C pool residence time.•Soil pH was the crucial variable in controlling the residence time of slow C pool.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
NaGlobal vigation Satellite System (GNSS) positioning technology is widely used for its high precision, global, and all-weather service. However, in complex environments such as urban canyons, GNSS ...performance is often degraded due to signal occlusion and even fails to achieve positioning due to the insufficient visible satellites. Because of the characteristics of large bandwidth, low latency, and high Base Station (BS) density, the fifth-Generation mobile communication (5G) technology has gradually become a trend for positioning in cities while offering traditional communication service. To supply the communication demands of the User Equipment (UE), only one BS is usually considered to establish a connection with the UE during the BS construction. However, the positioning accuracy with a single BS in urban canyons will be significantly reduced. To further improve the positioning accuracy in such extreme scenarios, this paper proposes a simplified 5G/GNSS fusion positioning system architecture using observations from only a 5G BS and a GNSS satellite. In this system, the GNSS receiver is mounted on the 5G BS, and the measurements provided by the receiver are used to form the differential code and complete the position estimation. The positioning mathematical models of the system based on the original code and differential code are derived. Then, the impacts of the measurements noise and the time synchronization error on the positioning accuracy are analyzed theoretically. Finally, the positioning performance is investigated by a set of simulation experiments. Numerical results show that under the existing 5G measurement noise and 2 m's code measurement noise, the improvement of the differential code based fusion positioning compared with the 5G-only positioning is more than 32%, which is also about 6% higher than the original code based fusion positioning. Besides, this improvement is not affected by the time synchronization error between the BS and the GNSS satellite.
In this paper, we develop an efficient and accurate procedure of electromagnetic multipole decomposition by using the Lebedev and Gaussian quadrature methods to perform the numerical integration. ...Firstly, we briefly review the principles of multipole decomposition, highlighting two numerical projection methods including surface and volume integration. Secondly, we discuss the Lebedev and Gaussian quadrature methods, provide a detailed recipe to select the quadrature points and the corresponding weighting factor, and illustrate the integration accuracy and numerical efficiency (that is, with very few sampling points) using a unit sphere surface and regular tetrahedron. In the demonstrations of an isotropic dielectric nanosphere, a symmetric scatterer, and an anisotropic nanosphere, we perform multipole decomposition and validate our numerical projection procedure. The obtained results from our procedure are all consistent with those from Mie theory, symmetry constraints, and finite element simulations.
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