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This paper proposes the Lock-Position-Based RFID Adaptive Parallel Collision Tree (LAPCT) algorithm to address the issues of excessive time slots required in the identification process of collision tree algorithms for multiple tags and the high communication complexity between the reader and multiple tags. The LAPCT algorithm adopts a single-query multiple-response mechanism and dynamically divides the response sub-cycle numbers in the identification cycle based on an adaptive strategy. It uses Manchester encoding to lock collision positions and generate a common query prefix, effectively reducing the number of reader queries. This reduction in queries decreases the total number of required time slots and transmitted bits during the reader–tag communication process, thereby improving the efficiency of multiple tag recognition. Theoretical and simulation experiments demonstrate that compared to similar algorithms, the LAPCT algorithm achieves a maximum reduction of 37% in total time slots required, a maximum improvement of 30% in recognition efficiency, and a maximum reduction of 90% in communication complexity. Furthermore, with an increase in the number of tags, the performance advantages of the LAPCT algorithm become more pronounced, making it suitable for large-scale tag scenarios. [ABSTRACT FROM AUTHOR]

Low Earth orbit (LEO) satellites have high signal strength and faster geometry changes over short periods, offering unique advantages in navigation augmentation. Integrating LEO satellites into the navigation system can help augment the performance of the global satellite navigation system and break the dilemma of the existing navigation system with limited services in challenging environments. Constellation design is the key before establishing a complete LEO navigation augmentation platform. Therefore, in this study, two LEO navigation augmentation constellations, Polar/Walker (S1) and Walker/Walker (S2) with different inclinations, are designed and optimized using the non-dominated sorting genetic algorithm III (NSGA-III). The global average geometric dilution of precision (GDOP) of BDS-3 is reduced from 1.56 to 0.92 and 0.95, and the average visible satellite number is improved from 11.74 to 27.83 and 25.72 with the navigation augmentation of the optimized constellations. To further validate the navigation augmentation effect of two LEO constellations on BDS-3 precision point positioning (PPP), nine stations at different latitudes were selected for LEO augmented BDS-3 PPP simulation experiments. The results show that after adding S1 and S2 constellations to BDS-3, respectively, the convergence times of the nine stations are reduced by 35.5%∼96.5% and 43.7%∼96.2%, and the positioning accuracy is improved by 5.7%∼71.9% and 24.2%∼69.5%, respectively. Overall, each S1 and S2 constellations can significantly improve the global service performance and PPP performance of BDS-3. [ABSTRACT FROM AUTHOR]

Soil environmental quality assessment traditionally focuses on a single objective. Therefore, related results only reflect the pollution of the assessment objective and ignore the interaction and relationships between soil, ecology, and human health. In this study, we collected and filtered data about heavy metal content (Cr, Pb, Cd, Hg, As, Cu, Zn, and Ni) in city soils from more than 1000 published papers. Spatial multi-criteria decision-making theory was used to establish the combined evaluation model of soil environmental quality using the geochemical accumulation, ecological risk, non-carcinogenic risk, and carcinogenic risk indexes. Our results showed that the pollution degree and elements causing most pollution were significantly different when these different methods were used for assessment. The proposed framework was able to unify the overall pollution trend in regional soil environmental quality assessment and could output more robust and reasonable assessment results of soil, ecology, and human health. The random forest model was used to analyze the potential sources for excessive accumulation of heavy metal elements in soils, and the results showed that the main potential sources were the proportion of secondary industry and urbanization rate, each with an average contribution ratio of 20%. This study provides comprehensive and specific information for the prevention and control of soil heavy metal pollution in China. [ABSTRACT FROM AUTHOR]

Accurate soil organic carbon (SOC) data are very important for management of agricultural production and climate change mitigation. Visible near-infrared diffuse reflectance spectroscopy is an inexpensive, non-destructive, efficient, and reliable technique for monitoring soil properties. Soil spectral libraries can contain large sets of diverse soil data for empirical calibration. In this study, we focused on improving the prediction accuracy of the SOC content at the local field scale in Tibet using field-wet, intact spectra and different spectral libraries. The direct standardization algorithm and piecewise direct standardization algorithm were used to remove the influence of environmental factors from the in situ vis-NIR spectra. These algorithms effectively removed the influence of environment factors from the field-wet, intact spectra. The ratio of performance to deviation values for prediction of the SOC content using the field and laboratory spectra with the local spectral library were 1.57 and 1.98, respectively. The local spectral library models outperformed spiked national spectral library models and had higher ratio of performance to deviation values for shrub meadows, forests, and the total dataset. [ABSTRACT FROM AUTHOR]

Summary: In Arabidopsis, although studies have demonstrated that phytochrome A (phyA) and phyB are involved in blue light signaling, how blue light‐activated phytochromes modulate the activity of the CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1)‐SUPPRESSOR OF PHYA‐105 (SPA1) E3 complex remains largely unknown. Here, we show that phyA responds to early and weak blue light, whereas phyB responds to sustainable and strong blue light. Activation of both phyA and phyB by blue light inhibits SPA1 activity. Specifically, blue light irradiation promoted the nuclear import of both phytochromes to stimulate their binding to SPA1, abolishing SPA1's interaction with LONG HYPOCOTYL 5 (HY5) to release HY5, which promoted seedling photomorphogenesis. [ABSTRACT FROM AUTHOR]

There are special ionospheric phenomena in the equatorial and South African region, e.g., equatorial plasma bubbles and broadcast ionospheric model correction anomalies which result in unique ionospheric characteristics. In this paper, we analyze the ionospheric characteristics of the experimental region using the latest GNSS dual-frequency real-world data from 2014 to 2020. This is then used as a benchmark to analyze the performance of IRI-2016, IRI Plas-2017, and NeQuick 2 empirical models and their electron content distribution at different altitudes. Finally, the correlation between the electron content of the African region and the solar activity parameters is explored. The results show that:①The annual variation of electron content in the far equatorial region does not have obvious spring-autumn bimodal structure and the electron content in the near-equatorial region is much higher than that in the far equatorial region.②Empirical models generally overestimate the electron content of the region with the IRI-2016 model consistently achieves the highest performance, the NeQuick 2 model achieves the lowest accuracy in high solar activity years, and the IRI Plas-2017 model is the worst in mid and low solar activity years.③The IRI Plas-2017 model has a relatively stable share of each layer, whereas the NeQuick 2 model has a large share of each layer influenced by solar activity. The top electron content has the largest share of the total electron content, and the plasma layer has the smallest share.④In low solar activity years, the experimental region shows solar activity and electron content correlation anomalies which are negatively correlated. Overall the EUV index has the largest correlation coefficient with the ionosphere, and the SSN has the worst correlation in this region. [ABSTRACT FROM AUTHOR]

In recent years, due to the rise of social, biological, and other rich content graphs, several novel community detection methods using structure and node attributes have been proposed. Moreover, nodes in a network are naturally characterized by multiple community memberships and there is growing interest in overlapping community detection algorithms. In this paper, we design a weighted vertex interaction model based on distance dynamics to divide the network, furthermore, we propose a distance Dynamics‐based Overlapping Semantic Community detection algorithm(DOSC) for node‐attribute networks. The method is divided into three phases: Firstly, we detect local single‐attribute subcommunities in each attribute‐induced graph based on the weighted vertex interaction model. Then, a hypergraph is constructed by using the subcommunities obtained in the previous step. Finally, the weighted vertex interaction model is used in the hypergraph to get global semantic communities. Experimental results in real‐world networks demonstrate that DOSC is a more effective semantic community detection method compared with state‐of‐the‐art methods. [ABSTRACT FROM AUTHOR]

A new generation of satellites aimed for the BeiDou-3 global positioning system (BDS-3) has recently been launched. These satellites will play a crucial role in its globalization process. The performance of the BDS-3 experimental satellites has been addressed in previous works. However, performance analysis of the orbits of BDS-3 satellites is still lacking. Using the observation data of the B1I and B3I frequency signals across different stations, this paper provides quality analysis, precise orbit determination (POD), and orbit comparison. The results presented here show that the ranging accuracy of BDS-3 is superior to that of the BeiDou-2 system (BDS-2). The satellite-induced code bias of BDS-2 satellite is not obvious on BDS-3 satellite. The orbit accuracy of BDS-3 satellite is superior to the BDS-2 satellite. The average three-dimensional root-mean-square error (RMS) of two-day overlapping arcs for BDS-3 satellite orbits is within 0.1 m, and the satellite laser ranging (SLR) validation reports that the orbit radial-track is within 6 cm. [ABSTRACT FROM AUTHOR]

Satellite navigation systems are vulnerable. To guarantee the positioning, navigation and timing (PNT) safety of core infrastructure, it is necessary to establish a secure PNT system with hybrid physical principles. In this paper, the augmentations of the BeiDou satellite system (BDS) itself are analysed, namely augmentations through the BDS inter-satellite link, BDS geostationary orbit (GEO) and inclined geostationary orbit (IGSO) satellites, and BDS PNT services supported by low earth orbit (LEO) satellites. Then, taking BDS as the core component, the comprehensive PNT infrastructure seamlessly covering deep space and deep ocean is described, consisting of the deep space PNT constellation, the sea-floor PNT sonar beacon network, and the ground-based low frequency and very low frequency (VLF) long wave radio stations. Moreover, the key technologies of resilient PNT application matching comprehensive PNT and various autonomous perception PNT information are discussed, such as resilient PNT sensor integration, the resilient PNT functional model and the resilient stochastic model. As a future development direction, the key factors of intelligent PNT services are analysed, including the intelligent perception of PNT application scenes, the intelligent optimization of PNT functional and stochastic models and the intelligent fusion of multisource PNT information. [ABSTRACT FROM AUTHOR]

BeiDou Global Navigation Satellite System (BDS-3) broadcasts multifrequency signals that offer more choices of frequencies and more signal combinations for positioning. This paper analyzes the effect of timing group delay (TGD) and differential code bias (DCB) of BDS-3 on the corresponding triple-frequency positioning. The triple-frequency observation models of BDS-3 are summarized and the DCB correction models are derived for the four different frequency combinations of triple-frequency ionospheric-free (IF) combination (IF123), two dual-frequency IF combinations (IF1213) and triple-frequency uncombined (UC123) positioning modes. Standard point positioning (SPP) and precise point positioning (PPP) experiments were conducted using 30 days of observations from 25 multi-GNSS experiment (MGEX) stations. The results show that the TGD/DCB correction has a significant impact on the accuracy of SPP. The positioning accuracy using IF123 and IF1213 models improved by about 73~90% after TGD correction, in comparison to a 27~30% improvement achieved using the UC123 model. In addition, the correction effect of DCB is slightly better than TGD. The DCB correction significantly improves accuracy in the initial epoch of the PPP, which helps the convergence of the filtering and reduces the convergence time. The average convergence times of IF123, IF1213 and UC123 are 26.1, 26.9 and 38.3 min, respectively, which are reduced by 6.79, 2.54 and 8.59% with DCB correction. The pseudorange residuals are closer to zero-mean random noise after DCB correction. Furthermore, the DCB affects the evaluation of the inter-frequency bias (IFB), ionospheric delay and floating ambiguity parameters. However, the tropospheric delay is almost unaffected by DCB. [ABSTRACT FROM AUTHOR]

Many anti-collision protocols have been proposed at present. Almost all known protocols exhibit an overall identification efficiency smaller than 50%. And all of them are proposed for general purpose applications and do not consider the distribution characteristic of tag IDs in different radio frequency identification (RFID) systems. In real world, there are many RFID systems, in which the tag IDs are mostly distributed continuously, such as in container terminals, warehouse management, supply chain management, and so on. This paper presents an efficient anti-collision protocol, named improved collision tree protocol (ICT), to identify RFID tags simultaneously. The main novelties of this paper include that the duality and certainty principle is introduced and used in ICT to improve the tag identification efficiency, and the continuous and partially continuous distributions of tag IDs are taken into account in this paper. Both the theoretical and experimental results indicate that ICT improves the tag identification efficiency up to 100% when the tag IDs are distributed continuously, and always above 50% even when the tag IDs are distributed uniformly. For straightforward and efficient, ICT can be used in various RFID tag identification conditions, especially when the tag IDs are distributed continuously or partially continuously. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

With the emergence of more and more computing-intensive and latency-sensitive applications, insufficient computing power and energy of user devices has become a common phenomenon. Mobile edge computing (MEC) is an effective solution to this phenomenon. MEC improves task execution efficiency by offloading some tasks to edge servers for execution. In this paper, we consider a device-to-device technology (D2D)-enabled MEC network communication model, and study the subtask offloading strategy and the transmitting power allocation strategy of users. The objective function is to minimize the weighted sum of the average completion delay and average energy consumption of users, which is a mixed integer nonlinear problem. We first propose an enhanced particle swarm optimization algorithm (EPSO) to optimize the transmit power allocation strategy. Then, we utilize the Genetic Algorithm (GA) to optimize the subtask offloading strategy. Finally, we propose an alternate optimization algorithm (EPSO-GA) to jointly optimize the transmit power allocation strategy and the subtask offloading strategy. The simulation results show that the EPSO-GA outperforms other comparative algorithms in terms of the average completion delay, average energy consumption, and average cost. In addition, no matter how the weight coefficients of delay and energy consumption change, the average cost of the EPSO-GA is the least. [ABSTRACT FROM AUTHOR]

A stable and efficient anti-collision protocol is very important for tags identification in many radio frequency identification (RFID) system such as flow productions and automatic controls. In this paper, we introduce an efficient anti-collision protocol named collision tree protocol (CT) and analyze the stability of it in detail. Both theoretical results and experimental results indicate that the performance of CT is only dependent on the number of tags to be identified and not influenced by the distribution of tag IDs and other factors, and the average performance of CT for one-tag identification converges to a constant. According to the definition of the stability of an anti-collision protocol, CT is a stable anti-collision protocol for RFID tag identification. The stability proposed in this paper provides a new performance metric for evaluating the performance of different anti-collision protocols for RFID tag identification. As a stable protocol, the time delay and the power consumption for one-tag identification of CT tend to be constant. Therefore, CT can be applied to various tags identification systems and especially suited to the RFID systems in which both the time delay and the power consumption for tags (or objects) identification are required to be limited and stable. [ABSTRACT FROM AUTHOR]

Abstract: This paper studies the asymptotic behavior of solutions for the three-component reversible Gray–Scott model on infinite lattices. We first prove the existence of a global attractor for the generated semigroup. Then we give an upper bound of the Kolmogorov -entropy for the obtained global attractor. [Copyright &y& Elsevier]

Osteoporosis (OP) results from an imbalance between bone formation, which is regulated by osteoblasts, and bone resorption, which is mediated by osteoclasts. MicroRNA-22-3p (miR-22-3p) expression is decreased during the process of osteoclast differentiation and p38α mitogen-activated protein kinase (MAPK)14 promotes the proliferation and differentiation of osteoclast progenitors. However, whether miR-22-3p could target MAPK14 to regulate the progression of OP remains unknown, which was the aim of the present study. CD14+ PBMCs were used for the establishment of osteoclastic differentiation in vitro. In the present study, reverse transcription quantitative PCR was used to determine the mRNA expression of MAPK14, tartrate resistant acid phosphatase (TRAP), nuclear factor of activated T-cells (NFATC1) and cathepsin K (CTSK). Western blotting was applied to determine the protein expression of MAPK14, TRAP, NFATC1, CTSK, p-p65 and p65. Dual luciferase reporter assay was applied to confirm the relation between miR-22-3p and MAPK14. Cell Counting Kit-8 assay and flow cytometry assays were used to determine the cell proliferation and cell apoptosis, respectively. The results demonstrated that miR-22-3p expression was lower while MAPK14 expression was higher in the serum from patients with OP compared with healthy volunteers. Furthermore, miR-22-3p expression was negatively correlated with MAPK14 expression in patients with OP. In addition, miR-22-3p expression was decreased and MAPK14 expression was increased during the progression of CD14+peripheral blood mononuclear cells (PBMCs) osteoclastic differentiation in a time-dependent manner. Furthermore, miR-22-3p inhibited the proliferation and differentiation and promoted the apoptosis of CD14+PBMCs by targeting MAPK14. In summary, the findings from the present study suggested that miR-22-3p may serve a potential therapeutic role in patients with OP. [ABSTRACT FROM AUTHOR]

• The contents and spatial distributions of soil heavy metals were well predicted. • Thirteen environmental factors related to heavy metal pollution were considered. • Soil pollution was mainly affected by soil pH, PM 2.5 and polluting enterprises. • Potential risk areas were classified and identified by cluster analysis. • The cooperative use of RF and FKM supported efficient soil management. From the perspective of the mechanism of soil pollution, it is difficult to explain the process of predicting the spatial distributions of soil heavy metal pollution using traditional geostatistical methods at a regional scale. Furthermore, few methods are available to proactively identify potential risk areas for preventing soil contamination. In this study, we selected 13 environmental factors related to the accumulation of soil heavy metals based on the source-sink theory. Then, the fuzzy k-means method in combination with the random forest (RF) method was used to classify potential risk areas. The concentrations and spatial distributions of the heavy metals were well predicted by RF, and the average values of the root mean square error of the prediction and R 2 were 4.84 mg kg−1 and 0.57, respectively. The results indicated that the soil pH, fine particulate matter, and proximity to polluting enterprises significantly influenced the heavy metal pollution in soils, and the environmental variables varied significantly across the identified subregions. This study provides a theoretical basis for the sustainable management and control of soil pollution at the regional scale. [ABSTRACT FROM AUTHOR]

The basic system of the BeiDou global navigation satellite system (BDS-3) with 18 satellites has been deployed since December 2018. As the primary frequency standard, BDS-3 satellites include two clock types with the passive hydrogen maser (PHM) and the rubidium atomic frequency standard (RAFS). Based on the final precise orbit and clock product from Xi'an Research Institute of Surveying and Mapping (XRS), the atomic clock performance of BDS-3 satellites is evaluated, including the frequency accuracy, frequency drift rate, and frequency stability, and compared with GPS block IIF satellites with RAFS, Galileo satellites with PHM, and BDS-2 satellites. A data auto-editing procedure to preprocess clock data and assess the clock performance is developed, where the assessed results are derived at each continuous data arc and the outliers are excluded properly. The stability of XRS product noise is given by using some stations equipped with high-precision active hydrogen masers (AHM). The best stability is 8.93 × 10−15 and 1.85 × 10−15 for the averaging time of 10,000 s and 1 day, which is basically comparable to one-third of the in-orbit PHM frequency stability. The assessed results show the average frequency accuracy and drift rate of BDS-3 with RAFS are slightly worse while the stability is better than BDS-2 medium earth orbit (MEO) satellites. The 10,000 s stability is better but the 1-day stability is worse than GPS, which may be related to the performance of the BDS-3 RAFS clock. As for BDS-3 with PHM, the frequency accuracy is slightly worse than Galileo PHM satellites; the drift rate, when excluding C34 and C35, is basically comparable to Galileo and significantly better than GPS satellites; the stability is comparable to Galileo, where the 10,000 s stability is slightly worse than Galileo and better than GPS. The 1-day stability among BDS-3 PHM, GPS IIF RAFS, and Galileo PHM satellites is basically comparable. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) is one of the most important crops worldwide. Photoperiod, light quality, and light intensity in the environment can affect the growth, development, yield, and quality of maize. In Arabidopsis (Arabidopsis thaliana), cryptochromes are blue-light receptors that mediate the photocontrol of stem elongation, leaf expansion, shade tolerance, and photoperiodic flowering. However, the function of maize cryptochrome ZmCRY in maize architecture and photomorphogenic development remains largely elusive. The ZmCRY1b transgene product can activate the light signaling pathway in Arabidopsis and complement the etiolation phenotype of the cry1-304 mutant. Our findings show that the loss-of-function mutant of ZmCRY1b in maize exhibits more etiolation phenotypes under low blue light and appears slender in the field compared with wild-type plants. Under blue and white light, overexpression of ZmCRY1b in maize substantially inhibits seedling etiolation and shade response by enhancing protein accumulation of the bZIP transcription factors ELONGATED HYPOCOTYL 5 (ZmHY5) and ELONGATED HYPOCOTYL 5-LIKE (ZmHY5L), which directly upregulate the expression of genes encoding gibberellin (GA) 2-oxidase to deactivate GA and repress plant height. More interestingly, ZmCRY1b enhances lodging resistance by reducing plant and ear heights and promoting root growth in both inbred lines and hybrids. In conclusion, ZmCRY1b contributes blue-light signaling upon seedling de-etiolation and integrates light signals with the GA metabolic pathway in maize, resulting in lodging resistance and providing information for improving maize varieties. Maize cryptochrome 1b integrates light pathway with gibberellin metabolic pathway to reduce plant height and to enhance lodging resistance. [ABSTRACT FROM AUTHOR]

In a wide range of graph analysis tasks such as community detection and event detection, densest subgraph mining is important and primitive. With the development of social network, densest subgraph mining not only need to consider the structural data but also the attributes information, which descripts the features of nodes or edges. However, there are few researches on densest subgraph mining with attribute description. In this article, we only focus on the node‐attributed graph. According to the properties of structure and attribute in node‐attributed graphs, we define a novel dense subgraph pattern, called hybridized k‐truss in attribute‐augmented graph. A hybridized k‐truss is a subgraph that consists of structural nodes and attribute nodes, of which there are at least (k − 2) common neighbors between any two connected nodes. We introduce the densest hybridized truss problem, and the densest hybridized truss mapping to a densely connected subgraph with homogenous attributes in the original graph. We propose a densest hybridized truss extraction (DHTE) algorithm for node‐attributed graphs, to automatically find the densest subgraph with high density and homogenous attributes at the same time. Extensive experimental results of 21 real world datasets demonstrate the effectiveness and efficiency of DHTE over state‐of‐the‐art methods, through comparison about structural cohesiveness and attributive homogeneity. [ABSTRACT FROM AUTHOR]

This paper comprehensively analyzes the kinematic positioning performance of the third-generation BeiDou Navigation Satellite System (BDS-3) in car-borne, ship-borne, and air-borne scenes. Specifically, this work collects three types kinematic data, i.e., car-borne, ship-borne, and air-borne in three scenes including a real experimental scene, a simulated urban canyon or forest-covered scene, and a simulated regional interference or covered scene. Based on these datasets, the kinematic positioning performance of the BDS-3 interoperable signals of B1C and B2a is systematically analyzed and compared with GPS. The results demonstrate that the BDS-3 has slightly more visible satellites than GPS in the Asia-Pacific test area, and the positioning performance indexes for the B1C and B2a new signals are comparable to GPS in terms of the single point positioning (SPP), precise point positioning (PPP), and real-time kinematic (RTK) positioning. [ABSTRACT FROM AUTHOR]

Abstract Deriving the precise satellites orbits is a prerequisite condition for global navigation satellite system (GNSS) to provide the high precision positioning service. With GPS observations from low earth orbiters (LEOs) and terrestrial tracking stations, the orbit and clock parameters of GPS and LEO satellites can be estimated by a simultaneous least squares adjustment, called the combined precise orbit determination (CPOD) method. We select GPS data from three LEOs (GRACE, HY2A and Jason-2) and 150 terrestrial stations over half-month period to investigate the improved performance for GPS orbits when LEO GPS data are included in the process of POD. With the inclusion of LEO GPS data, the improved levels of GPS orbits are analyzed for different types of LEOs and different station networks. First the effect of LEO satellite with different orbital altitude and inclination on GPS orbits is analyzed under three ground station networks. Results show that the improved differences among different LEOs can achieve at millimeter and centimeter level for global and regional station networks, respectively. Then comparative experiments of POD with/without three LEOs are designed for global well-distributed (GW), global regional (GR), Asian-overseas regional (AOR) and Asian regional (AR) station networks, including fourteen station networks. The orbit accuracy of both GPS and LEO satellites and the improved level for GPS orbits are summarized. With the inclusion of three LEOs, contributions from LEO GPS data are comparative in GW and GR cases (more than 30 stations), 3D RMS for GPS orbits improving at mm level w.r.t. corresponding ground-only POD. With 20 stations, the improved levels are 4, 11 and 31 mm in the case of GW, AOR and AR, respectively; with 10 stations, the corresponding improved levels are 16, 24 and 87 mm. The improvements in GW and AOR cases are insignificant, within 3 cm level. In the AR case, the improved level can achieve at decimeter level, while the orbit accuracy with the inclusion of three LEOs is comparative to the inclusion of 5 ground stations evenly distributed in a non-regional area (i.e. AOR case). This study is helpful for deriving the final post-products or broadcast ephemerids for GNSS satellites when considering joining LEO data into the process of orbit determination. [ABSTRACT FROM AUTHOR]

Sintered products were prepared using coal gasification slag as the main raw material. Based on the comprehensive differential thermal analysis of dry mixture and the firing shrinkage pre-tests of green bodies as well as experience, the experiment was conducted according to orthogonal table L9(33), selecting the heating rate, the firing temperature, and the holding time as factors,2,3, and 4 °C · min-1,1 100,1 150, and 1 200 °C as well as 2,4, and 6 h as the corresponding levels, while the bulk density, the water absorption, the compressive strength and the thermal conductivity as evaluation indexes. The results show that:(1)the order of the influence degree of the firing system factors on the compressive strength, the bulk density and the water absorption of the sintered products is the firing temperature>the holding time>the heating rate, and that for the thermal conductivity is the firing temperature>the heating rate>the holding time;(2)generally, the optimal firing system is the heating rate of 2 °C · min-1, the firing temperature of 1 200 °C, and the holding time of 6 h, and the prepared sample has the bulk density of 1.84 g · cm-3, the compressive strength of 112 MPa, the water absorption of 1.44%, and the thermal conductivity of 1.239 W · m-1 · K-1. [ABSTRACT FROM AUTHOR]

With the gradual promotion and the application of difficult-to-machine materials such as titanium matrix composites in the aerospace field, high-quality hole-making technology has become a major demand in aviation manufacturing. In order to improve the hole-making quality of TiBw/TC4 composites, asynchronous mixed frequency vibration-assisted hole-making (AMFVAHM) method is proposed. The process consists of two steps: ultrasonic vibration-assisted drilling (UVAD) base hole and low-frequency torsional vibration-assisted helical milling (LFTVAHM) target hole. Based on this process, the cutting trajectory modeling is established, and the hole-making experiment on TiBw/TC4 composites is conducted. The experimental data show that during the hole expansion stage, the maximum XY-plane average milling force decreases by 30.96% and the maximum axial average milling force decreases by 24.49% compared with conventional helical milling (HM) when the torsional vibration frequency and the milling frequency are the same in LFTVAHM. The hole-making experiment shows that AMFVAHM can reduce the chip size, tool wear, and some other defects such as entrance/exit burrs, scratches, and fractures of the hole wall. Comparing with HM and UVAD, the verticality of hole wall increases by 71.43% and 86.21%, the inlet damage decreases by 27.98% and 31.60%, the outlet damage decreases by 2.80% and 14.47%, the hole wall roughness (Ra) decreases by 36.29% and 63.43%, and the maximum white layer thickness decreases by 19.99% and 67.66%. Meanwhile, AMFVAHM process not only reduces the cutting force and cutting temperature but also improves the hole-making quality due to the fretting friction effect of LFTVAHM in secondary hole expansion, which meets the need for high-quality hole-making of difficult-to-machine materials in practical engineering applications. [ABSTRACT FROM AUTHOR]

The dysfunction of CRALBP, a key regulator of the visual cycle, is associated with retinitis punctata albescens characterized by night vision loss and retinal degeneration. In this paper, we find that the expression of CRALBP is regulated by heat shock protein 90 (HSP90). Inhibition of HSP90α or HSP90β expression by using the CRISPR‐Cas9 technology downregulates CRALBP's mRNA and protein expression in ARPE‐19 cells by triggering the degradation of transcription factor SP1 in the ubiquitin–proteasome pathway. SP1 can bind to CRALBP's promoter, and inhibition of SP1 by its inhibitor plicamycin or siRNA downregulates CRALBP's mRNA expression. In the zebrafish, inhibition of HSP90 by the intraperitoneal injection of IPI504 reduces the thickness of the retinal outer nuclear layer and Rlbp1b mRNA expression. Interestingly, the expression of HSP90, SP1, and CRALBP is correlatedly downregulated in the senescent ARPE‐19 and Pig primary RPE cells in vitro and in the aged zebrafish and mouse retinal tissues in vivo. The aged mice exhibit the low night adaption activity. Taken together, these data indicate that the HSP90‐SP1 is a novel regulatory axis of CRALBP transcriptional expression in RPE cells. The age‐mediated downregulation of the HSP90‐SP1‐CRALBP axis is a potential etiology for the night vision reduction in senior people. [ABSTRACT FROM AUTHOR]

Carbon fiber–reinforced plastics (CFRP)/titanium alloy (Ti) stacks are extensively applied in the aerospace industry due to their excellent mechanical properties. However, their poor machinability poses great challenges. In this study, longitudinal-torsional ultrasonic vibration drilling (LT-UVD) is innovatively introduced to improve the quality of CFRP/Ti drilling. First, the separation mode of LT-UVD is analyzed by kinematic equations. Then, an experimental platform is built based on the LT-UVD vibration actuator to perform CFRP/Ti drilling experiments. The thrust force, interface temperature, hole wall quality, hole defects, Ti chip morphologies, and tool wear in LT-UVD are experimentally compared against conventional drilling (CD) and longitudinal ultrasonic vibration drilling (L-UVD). The experimental results show that, compared with CD and L-UVD, the thrust force of CFRP in LT-UVD decreases by 20.36–40.55% and 2.04–14.61%, while the thrust force of Ti decreases by 19.08–24.83% and 1.95–9.34%. Moreover, a relatively low maximum interface temperature is achieved in LT-UVD. In addition, the hole size accuracy, surface roughness for the hole's inner surface, and delamination factor are improved in LT-UVD. Fiber pullout defects, chip-breaking performance, and tool wear of CFRP are improved due to torsional vibration in LT-UVD. Finally, according to the high-speed camera, damage forms of the interface area are different when drilling CFRP/Ti stacks with various drilling sequences. [ABSTRACT FROM AUTHOR]

Due to the popular trend of combining online and offline interactions among users in event-based social networks (EBSNs), event recommendation which helps users discover their interesting events has become progressively urgent. Different from classic item recommendation, candidate events usually have short life cycle and occur in the future, resulting in severe challenges of data sparsity and cold-start. However, these problems are not well studied by previous works. In this article, we propose a Meta-Graph-based Attention Recommendation (MGAR) model to tackle aforementioned challenges by fully exploring complex semantic information based on meta-graphs extracted from EBSNs. First, we model the interactions between different entities as a heterogeneous information network and construct multiple meta-graphs to characterize the latent semantic preferences of users. Subsequently, we utilize convolutional neural networks and attention mechanisms to learn user and event latent factors by extracting semantic features of meta-graphs. Furthermore, the fused latent features are utilized to predict the ratings of a user to events and the events with top-k scores are recommended to the user. We collect several real-world datasets from a popular EBSN platform and conduct extensive experiments on the datasets. Our proposed model attains superior recommendation performance over several state-of-the-art approaches. Moreover, the results demonstrate that meta-graphs can reveal the semantic properties between users and events and improve event recommendation performance. [ABSTRACT FROM AUTHOR]

Finding groups in networks is very common in many practical applications, and most work mainly focus on dense groups. However, in scenarios like reviewer selection or weak social friends recommendation, we need to emphasize the privacy of individuals or minimize the possibility of information dissemination. So the internal relationship between individuals should be as tenuous as possible, but existing works cannot suit well to the requirement. Some works have focused on finding tenuous groups. However, these works only aim to find the most tenuous group and do not consider containing certain vertices. In this paper, we study the problem of finding tenuous groups in attributed networks that contain specific vertices. We first propose a new problem called Tenuous Attributed Group Query, and a new indicator, k-tenuity, to measure the structural tenuity of a group. Then we propose a method TAG-Basic to find proper groups by gradually selecting the vertices with optimal influence. We further design an advanced method TAG-ADV to improve the efficiency by forming a candidate set before selecting the optimal vertex. Experiment results show that k-tenuity is more effective than other state-of-the-art measurements, and our methods obtain the best result on group quality compared with other benchmark methods. [ABSTRACT FROM AUTHOR]

For the three types of GNSS system time offset monitoring approach, we analyze the basic principles and methods and made a comparison of their accuracy, reliability and implementation, and finding that the PPS-based method is more suitable for time offset monitoring. We present a detailed discussion and description, including hardware configuration, data collection and post processing content for the PPS-based method. In an experiment we use both GPS and GLONASS dual-mode receivers to generate the 1 PPS of GPS and GLONASS second pulse signals, and used the Stanford SR620 time interval counter for PPS precision measurement. We thereby obtained GPS and GLONASS system time offset measurement values, and adopted a FIR filter with a Hanning window to get the GPS and GLONASS system time offset average 317.1 ns, with a standard deviation of 5.01 ns. [ABSTRACT FROM AUTHOR]

Concept drift in data stream poses many challenges and difficulties in mining this tradition-distinct database. In this paper, we focus on detecting concept drift in evolving data stream. We propose a novel method to detect concept drift using entropy over an adaptive sliding window. In the method, the sliding window is not fixed but dynamically determined. Another distinct property is that the method integrates an algorithm to find the exact timestamp for retraining the classifier whenever a concept drift is detected. In the experiments, we evaluate our method on publicly available data streams containing various types of concept drifts, and then compare it with four well known concept drift detection methods. The experimental results show that compared with four benchmarks, the proposed method is better than or comparable with other methods for most cases. [ABSTRACT FROM AUTHOR]

Satellite antenna phase center offsets (PCOs) is an important error source in global navigation satellite system (GNSS). With GNSS observations in a global network, the PCOs estimation strategy generally uses a dual-frequency (DF) ionospheric-free (IF) combination as the observation model. This model cannot derive the PCO values at each frequency, which results in the PCOs of the third frequency being unavailable for GPS satellites in the igs14.atx product. In this contribution, the PCOs estimation method of the third frequency based on uncombined (UC) precise orbit determination (POD) model is developed. The PCOs of the first- and second frequencies are fixed to the known values while PCOs of the third frequency are regarded as estimated parameters. This method is tested on the PCO estimation of GPS L5 frequency by using 110 ground stations throughout the entire year of 2018. The averaged standard deviations of L5 PCOs over one year are derived, with x-, y-, and z-offsets being 0.2, 0.2, and 1.6 cm, respectively. The corresponding difference values of the derived weighing averaged PCOs compared to the values of the igs14.atx product are 0.2, 0.1, and 9.9 cm. The POD experiment is processed to validate the derived PCOs of L5 over a period of 50 days. Results show that the accuracy of orbits, clocks and station positions is slightly improved after using estimated PCOs. [ABSTRACT FROM AUTHOR]

Individuals with congenital or acquired prolongation of the QT interval, or long QT syndrome (LQTS), are at risk of life-threatening ventricular arrhythmia. LQTS is commonly genetic in origin but can also be caused or exacerbated by environmental factors. A missense mutation in the L-type calcium channel CaV1.2 leads to LQTS in patients with Timothy syndrome. To explore the effect of the Timothy syndrome mutation on the electrical activity and contraction of human cardiomyocytes, we reprogrammed human skin cells from Timothy syndrome patients to generate induced pluripotent stem cells, and differentiated these cells into cardiomyocytes. Electrophysiological recording and calcium (Ca2+) imaging studies of these cells revealed irregular contraction, excess Ca2+ influx, prolonged action potentials, irregular electrical activity and abnormal calcium transients in ventricular-like cells. We found that roscovitine, a compound that increases the voltage-dependent inactivation of CaV1.2 (refs 6-8), restored the electrical and Ca2+ signalling properties of cardiomyocytes from Timothy syndrome patients. This study provides new opportunities for studying the molecular and cellular mechanisms of cardiac arrhythmias in humans, and provides a robust assay for developing new drugs to treat these diseases. [ABSTRACT FROM AUTHOR]

BeiDou-3 Navigation Satellite System (BDS-3) satellites are equipped with the new generation GNSS signals B1C and B2a, which support the interoperability with GPS and Galileo systems. In this study, the pseudo-range multipath error and carrier phase observation noise of the BDS-3 B1C and B2a signals were evaluated based on zero baseline measurements from the day of year (DOY) 113 to 116, 2020. Further, the precision and performance of the single point positioning (SPP) and precise point positioning (PPP) are assessed at 9 stations. This assessment manifests that the standard deviations (STDs) of the pseudo-range multipath error are about 0.09 ~ 0.22 m, while STDs of the carrier phase observation noise are about 0.075 mm. For the single-frequency SPP, its positioning precision is about 2.03 ~ 4.85 m and 3.29 ~ 10.73 m at the 99.99% confidence level in horizontal and vertical directions, respectively, while the dual-frequency SPP precision is about 1.92 ~ 8.02 m and 4.81 ~ 12.77 m in horizontal and vertical directions, respectively. For the daily static PPP, the convergence time is about 20 ~ 30 min, while the daily positioning precision can reach 1.38 ~ 4.42 cm and -1.31 ~ 4.34 cm in horizontal and vertical directions, respectively. In general, the quality and the SPP and PPP performance of the BDS-3 B1C&B2a signals are comparable to the GPS and Galileo. [ABSTRACT FROM AUTHOR]

Late embryogenesis abundant (LEA) proteins are members of a large and highly diverse family that play critical roles in protecting cells from abiotic stresses and maintaining plant growth and development. However, the identification and biological function of genes of Secale cereale LEA (ScLEA) have been rarely reported. In this study, we identified 112 ScLEA genes, which can be divided into eight groups and are evenly distributed on all rye chromosomes. Structure analysis revealed that members of the same group tend to be highly conserved. We identified 12 pairs of tandem duplication genes and 19 pairs of segmental duplication genes, which may be an expansion way of LEA gene family. Expression profiling analysis revealed obvious temporal and spatial specificity of ScLEA gene expression, with the highest expression levels observed in grains. According to the qRT-PCR analysis, selected ScLEA genes were regulated by various abiotic stresses, especially PEG treatment, decreased temperature, and blue light. Taken together, our results provide a reference for further functional analysis and potential utilization of the ScLEA genes in improving stress tolerance of crops. [ABSTRACT FROM AUTHOR]

Traditional community detection methods in attributed networks (eg, social network) usually disregard abundant node attribute information and only focus on structural information of a graph. Existing community detection methods in attributed networks are mostly applied in the detection of nonoverlapping communities and cannot be directly used to detect the overlapping structures. This article proposes an overlapping community detection algorithm in attributed networks. First, we employ the modified X‐means algorithm to cluster attributes to form different themes. Second, we employ the label propagation algorithm (LPA), which is based on neighborhood network conductance for priority and the rule of theme weight, to detect communities in each theme. Finally, we perform redundant processing to form the final community division. The proposed algorithm improves the X‐means algorithm to avoid the effects of outliers. Problems of LPA such as instability of division and adjacent communities being easily merged can be corrected by prioritizing the node neighborhood network conductance. As the community is detected in the attribute subspace, the algorithm can find overlapping communities. Experimental results on real‐attributed and synthetic‐attributed networks show that the performance of the proposed algorithm is excellent with multiple evaluation metrics. [ABSTRACT FROM AUTHOR]

The hardware delay difference for different navigation signals in satellite or receiver channels is called Differential Code Bias (DCB). DCB is a major error of global navigation satellite system (GNSS), which may lead to tens of Total Electron Content unit (TECu) ionospheric delay errors or several-meter ranging errors. The basic system of BeiDou Navigation Satellite System has opened services and three new navigation signals, namely B1C, B2a at the end of 2018, and B2b at the end of 2019. As the BeiDou satellite broadcast clock difference is based on the phase center of the B3I signal antenna, it is necessary to estimated the DCB values of the new navigation signals relative to B3I. Considering that BDS broadcasts the BeiDou global ionospheric delay correction model (BDGIM) parameters with the highest precision, the method of solving satellite or receiver DCB based on the BDS-3 BDGIM parameter constraint is proposed and verified. Theoretical analysis shows that the mean square error of daily solution is about 0.63–1.96 ns. The measured data of 25 iGMAS stations from January 1 to 30, 2019, are used for verification. The results show that the solution precision of satellite DCB is better than 1.0 ns and that of receiver DCB is slightly worse. This method does not need the support of external ionospheric products and provides a possibility for online real-time estimating of the satellite and receiver DCB. [ABSTRACT FROM AUTHOR]

Community search is individualized and targeted, which identifies local communities containing query nodes and meeting specific conditions only according to users. Community search is only interested in communities that satisfy the designated criteria, and has a wide range of application scenarios in the real world. Traditional community search only uses the topology information, without considering the impact of node attributes information. And many existing algorithms can only deal with a single query node. Therefore, this paper defines the attribute community search problem of multiple query nodes on attribute graphs, which utilizes the edge connectivity as the structural tightness constraint and designs an attribute function as the attribute tightness constraint. To solve this problem, we design a framework that firstly finds the maximum k edge connected-component containing query as a candidate subgraph, then iteratively deletes the node with the least contribution to the attribute function from the candidate subgraph and adjusts the subgraph according to the structural constraints. We also design the attribute Steiner distance that synthesizes the structural information and attribute information, and propose an efficient heuristic expansion algorithm based on distance. The experimental results on several datasets show our proposed methods can find the community containing all query nodes with high tightness of structure and homogeneity of attributes. [ABSTRACT FROM AUTHOR]

This paper aims on slicing of monocrystalline silicon wafers using a newly developed diamond multi-wire reciprocating saw under ingot rocking process. A contact wire length model based on ingot rocking was established. The influence of motion parameters of ingot rocking on the surface quality of multi-wire sawn monocrystalline silicon wafers had been experimentally studied. The slicing surface morphology, surface roughness, and surface hardened layer were investigated by using scanning electron microscope, laser scanning microscopy, and microhardness tester. Results show that compared with the multi-wire cutting mode with an ingot rocking amplitude of 0°, ingot rocking (θm ≠ 0) can reduce the contact wire length of sawing by almost half at any time, and realize discontinuous and segmented sawing of large-diameter silicon wafers. By reducing the contact wire length, the cutting mode under ingot rocking can achieve better surface morphologies, and reduce roughness, thickness of the hardened layer and microhardness of the surface in silicon wafer cutting. Compared with the mode of multi-wire reciprocating sawing with an ingot rocking amplitude of 0°, an ingot rocking amplitude of 5°can reduce roughness, thickness of the hardened layer, and microhardness of the surface in silicon wafer cutting about 30.1%, 20.1%, and 11.3%. Though the ingot rocking amplitude did not significantly influence the contact wire length during the cutting process, the ingot rocking motion significantly influences the ingot feed speed, an ingot rocking amplitude of 5°instead of 3° or 7° is suggested for the best surface quality. [ABSTRACT FROM AUTHOR]

Destination prediction is an essential task in various mobile applications and up to now many methods have been proposed. However, existing methods usually suffer from the problems of heavy computational burden, data sparsity, and low coverage. Therefore, a novel approach named DestPD is proposed to tackle the aforementioned problems. Differing from an earlier approach that only considers the starting and current location of a partial trip, DestPD first determines the most likely future location and then predicts the destination. It comprises two phases, the offline training and the online prediction. During the offline training, transition probabilities between two locations are obtained via Markov transition matrix multiplication. In order to improve the efficiency of matrix multiplication, we propose two data constructs, Efficient Transition Probability (ETP) and Transition Probabilities with Detours (TPD). They are capable of pinpointing the minimum amount of needed computation. During the online prediction, we design Obligatory Update Point (OUP) and Transition Affected Area (TAA) to accelerate the frequent update of ETP and TPD for recomputing the transition probabilities. Moreover, a new future trajectory prediction approach is devised. It captures the most recent movement based on a query trajectory. It consists of two components: similarity finding through Best Path Notation (BPN) and best node selection. Our novel BPN similarity finding scheme keeps track of the nodes that induces inefficiency and then finds similarity fast based on these nodes. It is particularly suitable for trajectories with overlapping segments. Finally, the destination is predicted by combining transition probabilities and the most probable future location through Bayesian reasoning. The DestPD method is proved to achieve one order of cut in both time and space complexity. Furthermore, the experimental results on real-world and synthetic datasets have shown that DestPD consistently surpasses the state-of-the-art methods in terms of both efficiency (approximately over 100 times faster) and accuracy. [ABSTRACT FROM AUTHOR]

A novel model of the BeiDou Global Ionospheric delay correction Model (BDGIM) is used as the global broadcasting ionospheric correction model for the third generation of BeiDou Navigation Satellite System (BDS-3). It has been successfully implemented on five BDS-3 test satellites. The accuracy of this novel BDGIM model were evaluated using the final global ionosphere maps (GIM) products provided by the International Global Navigation Satellite System Service (IGS). Comparing with the IGS GIM final product, the root mean square (RMS) of the global correction accuracy of BDGIM was 3.57 total electron content unit (TECu) with a correction percentage of 77.2%. The average RMS at different latitudes was 3.11 TECu, with Percent of 75.2%. The mean RMS values of regions with lattilute larger than 52.5S and 62.5N were less than that of NeQuickG. Considering the distribution of the tracking stations using for calculating BDGIM coefficients, the RMS values in different regions were 3.09 TECu (Percent = 80.3%) and 3.21 TECu (Percent = 79.4%), respectively. The BDGIM coefficients was updated every two hours, comparing with NeQuickG model, the BDGIM better reflected the real changes of ionosphere. Considering that the accuracy of the non-broadcasted coefficients declines with broadcasting duration, the correction accuracy with nine broadcasted coefficients included in BDGIM was analyzed. RMS and Percent were 4.10 TECu and 72.8%, declining by about 0.53 TECu and 4.4% (maximum to 9.7%), respectively. [ABSTRACT FROM AUTHOR]

Large-scale soil organic carbon (SOC) stock assessment is expensive as a large number of samples must be collected and then their time-consuming measurements must be made in the laboratory. Previous studies have shown that visible-near-infrared reflectance (vis-NIR) spectroscopy can quickly predict SOC content at a low cost. However, the application of this method at the large scale remains challenging due to the high spatial heterogeneity of SOC and the spatially dependent relationships of soil spectra and SOC content. Here, we conducted large-scale soil sampling across China's forests and established the Chinese forest soil spectral library (CFSSL) by measuring SOC content and scanning the vis-NIR reflectance of 11, 213 soil samples. Compared with the traditional global partial least squares regression (PLSR) modeling method (R 2 = 0.75, RPIQ = 1.95), the clustering by fast research and find of density peak in combination with the Cubist model significantly improved the prediction ability of SOC content (R 2 = 0.96, RPIQ = 5.83). This study provided a cost-efficient spectroscopic methodology, including measurement and prediction modeling, for large-scale SOC estimation. • Chinese forest soil vis-NIR spectral library was developed with 11, 213 soil samples. • PLSR model is not able to precisely predict SOC content at large-scale. • DP + Cubist model significantly improves the spectroscopic prediction of SOC. [ABSTRACT FROM AUTHOR]

A foam ceramic was prepared using molybdenum tailings (97–99.5 wt%) as the raw material and SiC as the foaming agent. The results showed that with increasing SiC content, the liquid-phase viscosity decreased, which in turn enhanced the overall expansion of the system, leading to a decrease in the thermal conductivity. The effects of the SiC content on the bulk density, porosity, pore size, and thermal conductivity were investigated in detail. Moreover, the experimental results were compared with several analytical models, and we found that the parallel model closely agreed with the predictions. The sample prepared via sintering at 1150 °C using 2.5 wt% SiC and molybdenum tailings exhibited a low bulk density of 0.37 g/cm3, high porosity of 85.14%, and low thermal conductivity of 0.22W/m·K. Thus, the application of molybdenum tailings in the production of foamed materials is considered to have potential economic and environmental advantages. • The foam ceramic with high content (97–99.5 wt%) of molybdenum tailings. • The viscosity of molybdenum tailings with SiC during sintering process was characterized by high temperature microscope. • Effect of SiC content on the thermal conductivity of foam ceramic was investigated by theoretical models and actual test method. [ABSTRACT FROM AUTHOR]

Abstract FeSi 2 -glass ceramic composites are successfully synthesized in situ from Bayan Obo tailings, blast furnace slag, and fly ash by a melting method. The effects of Fe 2 O 3 on the crystallization behavior, microstructure, and performance of the composites have been investigated by differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, transmission electron microscopy, and mechanical performance tests. The results show that the glass ceramics are composed of a diopside dendritic crystal matrix (primary phase) in which FeSi 2 metal particles with diameter ∼5 μm are dispersed (dispersed phase). With increase in the amount of Fe 2 O 3 , the crystallization activation energy of the composites decreases from 343.20 to 309.71 kJ/mol and the Avrami parameter increases from 2.12 to 3.17. The composites exhibit the maximum density of 3.04 g/cm3, microhardness of 8.37 GPa, bending strength of 210.27 MPa, impact toughness of 3.68 kJ/m2, acid resistance of 97.91%, and alkali resistance of 98.85%, proving their high potential for various industrial applications. Highlights • Glass ceramic - metal composites has been synthesized in situ from Bayan Obo tailings, fly ash and blast furnace slag. • Glass ceramics are composed of a diopside dendritic crystal matrix in which FeSi 2 metal particles are dispersed. • The metal pinning effect promotes the crystallization process and improves the physicochemical properties of the samples. [ABSTRACT FROM AUTHOR]

Abstract Bayan Obo tailings (BOTs), fly ash (FAS), and stainless-steel slag (SSS) are industrial wastes that require reasonable, clean, and effective utilization for environment protection. The paper focuses on the structure and properties of glass-ceramics that were prepared by melting BOT, FAS, and SSS raw materials. The effect of CaF 2 on the viscosity, structure, and performance of CaO-Al 2 O 3 -MgO-SiO 2 (CAMS) slag glass-ceramics is determined by viscometer, differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and physicochemical properties measurements. The results show that moderate amounts of CaF 2 facilitates depolymerization of the silicate networks, which leads to a decrease in the melting temperature, viscosity and viscous activation energy of glass. However, the content of more than 3% CaF 2 results in a dramatic decreases in the chemical stability of the glass-ceramics because of the transformations of the main crystalline phase from diopside to anorthite, which is accompanied by fluorite precipitation. Highlights • Glass and glass-ceramics has been obtained by Bayan Obo tailings, fly ash and stainless-steel slag. • Moderate amounts of CaF 2 contributed to reduce the degree of polymerization of the silicate networks. • Excess CaF 2 content resulted in a dramatic decrease of the chemical stability of the glass ceramics. [ABSTRACT FROM AUTHOR]

In social network analysis, community detection on plain graphs has been widely studied. With the proliferation of available data, each user in the network is usually associated with additional attributes for elaborate description. However, many existing methods only concentrate on the topological structure and fail to deal with node‐attributed networks. These approaches are incapable of extracting clear semantic meanings for communities detected. In this paper, we combine the topological structure and attribute information into a unified process and propose a novel algorithm to detect overlapping semantic communities. Moreover, a new metric is designed to measure the density of semantic communities. The proposed algorithm is divided into 3 phases. First, we detect local semantic subcommunities from each node's perspective using a greedy strategy on the metric. Then, a supergraph, which consists of all these subcommunities is created. Finally, we find global semantic communities on the supergraph. The experimental results on real‐world data sets show the efficiency and effectiveness of our approach against other state‐of‐the‐art methods. [ABSTRACT FROM AUTHOR]

Team formation, which aims to form a team to complete a given task by covering its required skills, furnishes a natural way to help organizers complete projects effectively. In this work, we propose a new team hiring problem. Given a set of projects with required skills, and a pool of experts , each of which has his own skillset, compensation demand and participation constraint (i.e., the maximum number of projects the expert can participate in simultaneously), we seek to hire a team of participation-constrained experts to complete all the projects so that the overall compensation is minimized. We refer to this as the participation constrained team hire problem. To the best of our knowledge, this is the first work to investigate the problem. We also study a special case of the problem, where the number of projects is within the participation constraint of each expert and design an exact algorithm for it. Since participation constrained team hire problem is proven to be NP-hard, we design three novel efficient approximate algorithms as its solution, each of which focuses on a particular perspective of the problem. We perform extensive experimental studies, on both synthetic and real datasets, to evaluate the performance of our algorithms. Experimental results show that our exact algorithm far surpasses the brute-force solutions and works well in practice. Besides, the three algorithms behave differently when distinct facets of the problem are involved. [ABSTRACT FROM AUTHOR]

After the presentation of second-order correlation ranging principles with quantum entanglement, the concept of quantum measurement is introduced to dynamic satellite precise orbit determination. Based on the application of traditional orbit determination models for correcting the systematic errors within the satellite, corresponding models for quantum orbit determination (QOD) are established. This paper experiments on QOD with the BeiDou Navigation Satellite System (BDS) by first simulating quantum observations of 1 day arc-length. Then the satellite orbits are resolved and compared with the reference precise ephemerides. Subsequently, some related factors influencing the accuracy of QOD are discussed. Furthermore, the accuracy for GEO, IGSO and MEO satellites increase about 20, 30 and 10 times, respectively, compared with the results from the resolution by measured data. Therefore, it can be expected that quantum technology may also bring delightful surprises to satellite orbit determination as have already emerged in other fields. [ABSTRACT FROM AUTHOR]

1. Understand that the Wish Project is a low-cost intervention that can be implemented in small and large healthcare settings to improve the end-of-life experience 2. Understand that the Wish Project can provide a personal experience to patients and their families that is appropriate to individual cultures, beliefs, and values In the United States, about 35% of patients die in acute care settings. Inpatient care at the end of life is variable and influenced by many factors, including cultural values, religious beliefs, available resources, and family structure. Successful implementation of tools such as the 3 Wishes Project (3WP) has improved and personalized the dying process. Larger academic institutions with high-volume ICUs have been effective at deploying 3WP, but we were able to adapt key aspects of 3WP to improve end-of-life care at a smaller community hospital. To improve the end-of-life experience of patients and their families, a wish was granted before or after the death of a patient. The Wish Project was implemented at Stanford Healthcare–ValleyCare in Pleasanton, California by a team of 5 volunteers. Using a mixed-method study design, we collected demographic characteristics, cost effectiveness, and survey responses from patients and family members who participated in the Wish Project. Over a 32-month period (July 2018 to March 2020), 46 referrals were received, and 33 wishes were granted. Of the 13 ungranted wishes, 69% (9/13) were due to lack of desire for a wish and 31% (4/13) were due to lack of capacity to fulfill the wish. Of the completed wishes, 42% (14/33) were completed in the hospital and 58% (19/33) delivered to the patient's or family's home. The average cost for a wish was $46.56 (range $0-$325). Survey responses indicated that family members were very satisfied with the personalized nature of the care received. Many requested to personally support the program for future patients and families. The Wish Project was successfully implemented as a cost-effective end-of-life intervention in a community hospital setting. [ABSTRACT FROM AUTHOR]

Community detection is an important methodology for understanding the intrinsic structure and function of complex networks. Because overlapping community is one of the characteristics of real-world networks and should be considered for community detection, in this article, we propose an algorithm, called link-based label propagation algorithm (LinkLPA), to detect overlapping communities. Because the link partition is conceptually natural for the problem of overlapping community detection, LinkLPA first transforms node partition problem into link partition problem and employs a new label propagation algorithm with preference on links instead of nodes to detect communities due to the simplicity and efficiency of label propagation algorithm. Then the proposed LinkLPA performs a postprocessing to refine the detected overlapping communities by avoiding over-overlapping and incorrect partition of weak ties. Experimental results on a large number of real-world and synthetic networks show that the proposed method achieves high accuracy on detecting overlapping communities in networks. [ABSTRACT FROM AUTHOR]

Computing k -edge connected components can be used to capture closely related vertices in a graph. It is an important problem with many applications. Due to the high time complexities of traditional algorithms for computing k -edge connected components, it is difficult for them to be applied to efficiently process large scale graphs. In this paper, an early merging and splitting based maximal k -edge connected subgraph detection algorithm, named MSK, is proposed. It computes the k -edge connected components of a graph with an order list of vertices which is decided according to the connectivity of vertices in the graph. During the processing of the vertex list, if two vertices are k -edge connected, they are merged into a super-vertex. On the contrary , if the vertex pair does not satisfy the condition of k -edge connectivity, the related vertices and edges are removed from the graph, and the graph is decomposed into several subgraphs. The above steps are performed iteratively in the obtained subgraphs until each subgraph become a k -edge connected component. In order to further improve the time efficiency, an approximate algorithm PMSK is also proposed. The experimental results on a large number of real and synthetic graphs show that the proposed algorithms are accurate and more efficient than the state-of-the-art algorithms. [ABSTRACT FROM AUTHOR]