The unreasonable observation arrangements in the satellite operation control center(SOCC)may result in the observation data cannot be downloaded as scheduled.Meanwhile,if the operation instructions released by the sat...The unreasonable observation arrangements in the satellite operation control center(SOCC)may result in the observation data cannot be downloaded as scheduled.Meanwhile,if the operation instructions released by the satellite telemetry tracking center(STTC)for the on-board payloads are not injected on the specific satellites in time,the corresponding satellites cannot perform the observation operations as planned.Therefore,there is an urgent need to design an integrated instruction release,and observation task planning(I-IRO-TP)scheme by efficiently collaborating the SOCC and STTC.Motivated by this fact,we design an interaction mechanism between the SOCC and the STTC,where we first formulate the I-IRO-TP problem as a constraint satisfaction problem aiming at maximizing the number of completed tasks.Furthermore,we propose an interactive imaging task planning algorithm based on the analysis of resource distribution in the STTC during the previous planning periods to preferentially select the observation arcs that not only satisfy the requirements in the observation resource allocation phase but also facilitate the arrangement of measurement and control instruction release.We conduct extensive simulations to demonstrate the effectiveness of the proposed algorithm in terms of the number of completed tasks.展开更多
Objective:To further evaluate the efficacy and safety of low-dose glucocorticoids combined with tacrolimus in the treatment of adult idiopathic membranous nephropathy(IMN)in a clinical setting.Methods:We carried out a...Objective:To further evaluate the efficacy and safety of low-dose glucocorticoids combined with tacrolimus in the treatment of adult idiopathic membranous nephropathy(IMN)in a clinical setting.Methods:We carried out a single-center prospective study of 88 patients with IMN who were admitted into the Affiliated Hospital of Hebei University from January 2019 to December 2021,and the participants were divided into two groups based on their serum anti-PLA2R antibody levels:the negative group and the positive group.46 patients were positive for anti-PLA2R antibodies and 42 were negative.Results:After 6 months of treatment,the serum albumin,cholesterol,and 24h urine protein quantification in the anti-PLA2R negative group improved more significantly compared to the positive group(P<0.05);after 6 months of treatment,the remission rate of the positive group was significantly lower than that of the negative group,and(P<0.05);Conclusion:After treatment with tacrolimus combined with low-dose glucocorticoids,patients with idiopathic membranous nephropathy who were tested positive for anti-PLA2R antibodies had a higher overall remission rate compared those who were tested negative for serum anti-PLA2R antibodies.展开更多
The rapid development and continuous updating of the mega satellite constellation(MSC)have brought new visions for the future 6G coverage extension, where the global seamless signal coverage can realize ubiquitous ser...The rapid development and continuous updating of the mega satellite constellation(MSC)have brought new visions for the future 6G coverage extension, where the global seamless signal coverage can realize ubiquitous services for user terminals. However, global traffic demands present nonuniform characteristics. Therefore, how to ensure the on-demand service coverage for the specific traffic demand, i.e., the ratio of traffic density to service requirement per unit area, is the core issue of 6G wireless coverage extension exploiting the MSC. To this regard, this paper first discusses the open challenges to reveal the future direction of 6G wireless coverage extension from the perspective of key factors affecting service coverage performance, i.e., the network access capacity, space segment capacity and their matchingrelationship. Furthermore, we elaborate on the key factors affecting effective matchings of the aforementioned aspects, thereby improving service coverage capability.展开更多
For received signal strength(RSS)fingerprint based indoor localization approaches,the localization accuracy is significantly influenced by the RSS variance,device heterogeneity and environment complexity.In this work,...For received signal strength(RSS)fingerprint based indoor localization approaches,the localization accuracy is significantly influenced by the RSS variance,device heterogeneity and environment complexity.In this work,we present a high-adaptability indoor localization(HAIL)approach,which leverages the advantages of both relative RSS values and absolute RSS values to achieve robustness and accuracy.Particularly,a backpropagation neural network(BPNN)is devised in HAIL to measure the fingerprints similarities based on absolute RSS values.With this aid,the characteristics of the applied area could be specially learned such that HAIL could be adaptive to different environments.The experiments demonstrate that HAIL achieves high localization accuracy with the average localization error of 0.87 m in the typical environments.Moreover,HAIL has the minimum amount of large errors and decreases the average localization error by about 30%~50%compared with the existing approaches.展开更多
Climate system models are useful tools for understanding the interactions among the components of the climate system and predicting/projecting future climate change. The development of climate models has been a centra...Climate system models are useful tools for understanding the interactions among the components of the climate system and predicting/projecting future climate change. The development of climate models has been a central focus of the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences(LASG/IAP) since the establishment of the laboratory in 1985. In China, many pioneering component models and fully coupled models of the climate system have been developed by LASG/IAP. The fully coupled climate system developed in the recent decade is named FGOALS(Flexible Global Ocean-Atmosphere-Land System Model). In this paper, an application-oriented review of the LASG/IAP FGOALS model is presented. The improved model performances are demonstrated in the context of cloud-radiation processes, Asian monsoon, ENSO phenomena, Atlantic Meridional Overturning Circulation(AMOC) and sea ice. The FGOALS model has contributed to both CMIP5(Coupled Model Intercomparison Project-phase 5) and IPCC(Intergovernmental Panel on Climate Change) AR5(the Fifth Assessment Report). The release of FGOALS data has supported the publication of nearly 500 papers around the world. The results of FGOALS are cited ~106 times in the IPCC WG1(Working Group 1) AR5. In addition to the traditional long-term simulations and projections, near-term decadal climate prediction is a new set of CMIP experiment, progress of LAGS/IAP in the development of nearterm decadal prediction system is reviewed. The FGOALS model has supported many Chinese national-level research projects and contributed to the national climate change assessment report. The crucial role of FGOALS as a modeling tool for supporting climate sciences is highlighted by demonstrating the model's performances in the simulation of the evolution of Earth's climate from the past to the future.展开更多
Recently cellular networks have been densely and heterogeneously deployed indoors and outdoors to expand the network capacity,and thus the in-building propagation loss and the transmit power diversity of access points...Recently cellular networks have been densely and heterogeneously deployed indoors and outdoors to expand the network capacity,and thus the in-building propagation loss and the transmit power diversity of access points will exacerbate link heterogeneity and result in partial unidirectional strong interference.To make full use of the strong interference feature,we propose the successive interference cancellation and alignment(SICA)scheme in the K-user interference channel with partial unidirectional strong interference.SICA is designed to transmit two kinds of data streams simultaneously,the alignment streams and superposition streams.The alignment streams will follow the interference alignment criterion to maintain the optimal degrees of freedom(DoF)performance;the superposition streams are handled via successive interference cancellation at all the strongly interfered receivers to improve the overall achievable rate.The joint transceiver designs for SICA is modeled as a weighted sum rate(WSR)maximization problem,and then can be alternately solved for a local optimum according to the optimality equivalence between WSR and its corresponding weighted mean square error(WMMSE)problem.Simulation results have confirmed the sum rate improvement and DoF optimality of the proposed SICA scheme.展开更多
The efficient antenna scheduling strategy for data relay satellites(DRSs)is essential to optimize the throughput or delay of the satellite data relay network.However,these two objectives conflict with each other since...The efficient antenna scheduling strategy for data relay satellites(DRSs)is essential to optimize the throughput or delay of the satellite data relay network.However,these two objectives conflict with each other since the user satellites(USs)with higher priorities take up more transmission time of DRSs’antennas for greater throughput but the USs storing more packets cause a severer waiting delay to the whole network.To balance the conflicting metrics for meeting the delay-throughput integrated requirements,we formulate the antenna scheduling as a stochastic non-convex fractional programming,which is challenging to be solved.For the tractability,we equivalently transform the fractional programming to a parametric problem and implement the Lyapunov drift to guarantee the constraint of mean rate stability.By proposing a delay and throughput tradeoff based antenna scheduling algorithm,we further transform the parametric problem to a solvable weight matching problem.Simulation results reveal the feasible region of the preference control parameter for integrated QoS cases and its variation relationship with network delay and throughput.展开更多
SUNFLUX is a fast parameterization scheme for determination of the solar radiation at the Earth's surface. In this paper, SUNFLUX is further modified in the treatment of aerosols. A new aerosol parameterization schem...SUNFLUX is a fast parameterization scheme for determination of the solar radiation at the Earth's surface. In this paper, SUNFLUX is further modified in the treatment of aerosols. A new aerosol parameterization scheme is developed for five aerosol species. Observational data from Baseline Surface Radiation Network (BSRN), Surface Radiation Budget Network (SURFRAD) and Aerosol Robotic Network (AERONET) stations are used to evaluate the accuracy of the original and modified SUNFLUX schemes. General meteorological data are available at SURFRAD stations, but not at BSRN stations. Therefore, the total precipitable water content and aerosol data are obtained from AERONET stations. Fourteen stations are selected from both BSRN and AERONET. Cloud fraction data from MODIS are further used to screen the cloud. Ten-year average aerosol mixing ratios simulated by the CAM-chem system are used to calculate the fractions of aerosol optical depth for each aerosol species, and these fractions are further used to convert the observed total aerosol optical depth into the components of individual species for use in the evaluations. The proper treatment of multiple aerosol types in the model is discussed. The evaluation results using SUNFLUX with the new aerosol scheme, in terms of the BSRN dataset, are better than those using the original aerosol scheme under clear-sky conditions. However, the results using the SURFRAD dataset are slightly worse, attributable to the differences in the input water vapor and aerosol optical depth. Sensitivity tests are conducted to investigate the error response of the SUNFLUX scheme to the errors in the input variables.展开更多
Due to flexible deployment,unmanned aerial vehicle(UAV)mounted aerial access points are capable of expanding the coverage capabilities of existing terrestrial base stations(TBSs).Different from TBSs,however,UAV access...Due to flexible deployment,unmanned aerial vehicle(UAV)mounted aerial access points are capable of expanding the coverage capabilities of existing terrestrial base stations(TBSs).Different from TBSs,however,UAV access points(UAPs)are of high mobility in horizontal and vertical dimensions,which may deteriorate the coverage performance.Worsestill,the mobility of UAPs would as well increase the pressure of wireless backhaul.In this light,we investigate the performance of the cache-enabled UAV communications network(CUCN)in terms of network spatial throughput(ST)by analyzing the line of sight(LoS)connections and non-line of sight(NLoS)connections.It is found that the network ST is exponentially decreased with the square of UAP altitude.Furthermore,contrary to intuition,a large cache size may deteriorate the network ST when UAPs are over-deployed.The reason is that a large cache size increases the hit probability,which may increase the activation of UAPs and consequently result in complicated interference.Aiming to maximize the network ST,we optimize the cache strategy under limited backhaul.Remarkably,the results show that network ST could be substantially improved by the optimized cache strategy and the performance degeneration brought by UAP high mobility could be even eliminated especially when the UAP altitude is high.展开更多
Delay Tolerant Networks (DTNs) is a dynamic topology network, in which connection durations of each link are variable and paths between two nodes are intermittent. Most of protocols which are widely used in traditiona...Delay Tolerant Networks (DTNs) is a dynamic topology network, in which connection durations of each link are variable and paths between two nodes are intermittent. Most of protocols which are widely used in traditional wireless network are not suitable for DTNs. DTN adopts store-and-forward mechanism to cope with the problem of intermittent path. With limited storage of each node, it is a challenge for scheduling nodes’ transmission to avoid overflow of nodes’ buffers. In this paper we propose an optimal transmission scheduling algorithm for DTN with nodes’ buffer constraints. The object of the optimal algorithm is to get maximum throughput. We also present an algorithm for obtaining suboptimal transmission schedules. Our solution is certified through simulation, and it is observed that our solution can improve network performance in the aspects of avoiding overflow and increasing network throughput.展开更多
In this paper,we reveal the fundamental limitation of network densification on the performance of caching enabled small cell network(CSCN)under two typical user association rules,namely,contentand distance-based rules...In this paper,we reveal the fundamental limitation of network densification on the performance of caching enabled small cell network(CSCN)under two typical user association rules,namely,contentand distance-based rules.It indicates that immoderately caching content would significantly change the interference distribution in CSCN,which may degrade the network area spectral efficiency(ASE).Meanwhile,it is shown that content-based rule outperforms the distance-based rule in terms of network ASE only when small cell base stations(BSs)are sparsely deployed with low decoding thresholds.Moreover,it is proved that network ASE under distance-based user association serves as the upper bound of that under content-based rule in dense BS regime.To enable more spectrum-efficient user association in dense CSCN,we further optimize network ASE by designing a probabilistic content retrieving strategy based on distance-based rule.With the optimized retrieving probability,network ASE could be substantially enhanced and even increase with the growing BS density in dense BS regime.展开更多
Objective:To determine the risk factors of infection in patients with nephrotic syndrome.Methods:A retrospective study was conducted on 155 patients with nephrotic syndrome under our department from January 2019 to De...Objective:To determine the risk factors of infection in patients with nephrotic syndrome.Methods:A retrospective study was conducted on 155 patients with nephrotic syndrome under our department from January 2019 to December 2019.Among them,43 cases had infection,and the rate of infection was 27.74%.The risk factors of infection were analyzed.Results:Among the 155 patients with nephrotic syndrome,43 cases developed infection,including 3 cases of upper respiratory tract infection(6.98%),33 cases of lower respiratory tract infection(76.74%),3 cases of skin infection(6.97%),3 cases of urinary tract infection(6.97%),and 1 case of facial nerve infection(2.32%).Compared with the group without infection,the group with infection had lower serum albumin and immunoglobulin G(IgG)levels as well as higher serum creatinine and 24-hour urinary protein levels(P<0.05).Multivariate logistic regression analysis showed that decreased serum albumin(odds ratio[OR]=1.14;P<0.01)and IgG(OR=1.1;P<0.144)were independent risk factors for infection.Conclusion:Respiratory infection is the most common infection in nephrotic syndrome,and the decrease in serum albumin and IgG are independent risk factors for infection.展开更多
The outputs of the Chinese Academy of Sciences(CAS) Flexible Global Ocean–Atmosphere–Land System(FGOALS-f3-L) model for the baseline experiment of the Atmospheric Model Intercomparison Project simulation in the Diag...The outputs of the Chinese Academy of Sciences(CAS) Flexible Global Ocean–Atmosphere–Land System(FGOALS-f3-L) model for the baseline experiment of the Atmospheric Model Intercomparison Project simulation in the Diagnostic,Evaluation and Characterization of Klima common experiments of phase 6 of the Coupled Model Intercomparison Project(CMIP6) are described in this paper. The CAS FGOALS-f3-L model, experiment settings, and outputs are all given. In total,there are three ensemble experiments over the period 1979–2014, which are performed with different initial states. The model outputs contain a total of 37 variables and include the required three-hourly mean, six-hourly transient, daily and monthly mean datasets. The baseline performances of the model are validated at different time scales. The preliminary evaluation suggests that the CAS FGOALS-f3-L model can capture the basic patterns of atmospheric circulation and precipitation well, including the propagation of the Madden–Julian Oscillation, activities of tropical cyclones, and the characterization of extreme precipitation. These datasets contribute to the benchmark of current model behaviors for the desired continuity of CMIP.展开更多
The Chinese Academy of Sciences(CAS)Flexible Global Ocean Atmosphere Land System(FGOALS-f3-L)model datasets prepared for the sixth phase of the Coupled Model Intercomparison Project(CMIP6)Global Monsoons Model Interco...The Chinese Academy of Sciences(CAS)Flexible Global Ocean Atmosphere Land System(FGOALS-f3-L)model datasets prepared for the sixth phase of the Coupled Model Intercomparison Project(CMIP6)Global Monsoons Model Intercomparison Project(GMMIP)Tier-1 and Tier-3 experiments are introduced in this paper,and the model descriptions,experimental design and model outputs are demonstrated.There are three simulations in Tier-1,with different initial states,and five simulations in Tier-3,with different topographies or surface thermal status.Specifically,Tier-3 contains four orographic perturbation experiments that remove the Tibetan Iranian Plateau,East African and Arabian Peninsula highlands,Sierra Madre,and Andes,and one thermal perturbation experiment that removes the surface sensible heating over the Tibetan Iranian Plateau and surrounding regions at altitudes above 500 m.These datasets will contribute to CMIP6’s value as a benchmark to evaluate the importance of long-term and short-term trends of the sea surface temperature in monsoon circulations and precipitation,and to a better understanding of the orographic impact on the global monsoon system over highlands.展开更多
Software- defined networking (SDN) is a promising technology for next-generation networking and has attracted much attention from academics, network equipment manufacturer, network operators, and service providers. ...Software- defined networking (SDN) is a promising technology for next-generation networking and has attracted much attention from academics, network equipment manufacturer, network operators, and service providers. It has found center, and enterprise networks. applications in mobile, data The SDN architecture has a centralized, programmable control plane that is separate from the data plane. SDN also provides the ability to control and manage virtualized resources and networks without requiring new hardware technologies. This is a major shift in networking technologies.展开更多
Cloud dominates influence factors of atmospheric radiation, while aerosol–cloud interactions are of vital importance in its spatiotemporal distribution. In this study, a two-moment(mass and number) cloud microphysics...Cloud dominates influence factors of atmospheric radiation, while aerosol–cloud interactions are of vital importance in its spatiotemporal distribution. In this study, a two-moment(mass and number) cloud microphysics scheme, which significantly improved the treatment of the coupled processes of aerosols and clouds, was incorporated into version 1.1 of the IAP/LASG global Finite-volume Atmospheric Model(FAMIL1.1). For illustrative purposes, the characteristics of the energy balance and cloud radiative forcing(CRF) in an AMIP-type simulation with prescribed aerosols were compared with those in observational/reanalysis data. Even within the constraints of the prescribed aerosol mass, the model simulated global mean energy balance at the top of the atmosphere(TOA) and at the Earth’s surface, as well as their seasonal variation, are in good agreement with the observational data. The maximum deviation terms lie in the surface downwelling longwave radiation and surface latent heat flux, which are 3.5 W m-2(1%) and 3 W m-2(3.5%), individually. The spatial correlations of the annual TOA net radiation flux and the net CRF between simulation and observation were around 0.97 and 0.90, respectively. A major weakness is that FAMIL1.1 predicts more liquid water content and less ice water content over most oceans. Detailed comparisons are presented for a number of regions, with a focus on the Asian monsoon region(AMR). The results indicate that FAMIL1.1 well reproduces the summer–winter contrast for both the geographical distribution of the longwave CRF and shortwave CRF over the AMR. Finally, the model bias and possible solutions, as well as further works to develop FAMIL1.1 are discussed.展开更多
In this study, variation in the frequency of thermal discomfort days over China during the period of 1961-2014,including heat discomfort days(HDDs) and cold discomfort days(CDDs), and the influence of external forcing...In this study, variation in the frequency of thermal discomfort days over China during the period of 1961-2014,including heat discomfort days(HDDs) and cold discomfort days(CDDs), and the influence of external forcings on it are discussed. HDDs are the conditions of overheating and overhumidity(represented by humidity index), and CDDs reflect the dangers from cold temperatures and winds(represented by wind chill index). Observations show significant increases(decreases) in the frequency of HDDs(CDDs) over China from 1961 to 2014, with clear regional distinctions. The historical ALL and greenhouse gas(GHG) simulations can sufficiently reproduce the spatial patterns of the observational trend in the frequency of both HDDs and CDDs over China. Further, the impacts of GHG and anthropogenic forcings on the HDDs(CDDs) are detectable over China, except for central and eastern China, based on the optimal fingerprinting method. GHG forcing is identified as a dominant factor for the observational changes in the frequency of HDDs over southern China;GHG and anthropogenic forcings have dominant effects on the variation in the frequency of CDDs over southwestern China. Although trends in the frequency of HDDs and CDDs in historical aerosol forcing simulations seems to be opposite to observations, an aerosol signal fails to be detected. Natural forcing contributes to the observational variation in the frequency of HDDs over northwestern China. In addition, the future projections of thermal discomfort days indicate that Chinese residents will face more threats of heat discomfort and fewer threats of cold discomfort in the future under global warming.展开更多
The emergency relating to software-defined networking (SDN), especially in terms of the prototype associated with OpenFlow, provides new possibilities for innovating on network design. Researchers have started to ex...The emergency relating to software-defined networking (SDN), especially in terms of the prototype associated with OpenFlow, provides new possibilities for innovating on network design. Researchers have started to extend SDN to cellular networks. Such new programmable architecture is beneficial to the evolution of mobile networks and allows operators to provide better services. The typical cellular network comprises radio access network (RAN) and core network (CN); hence, the technique roadmap diverges in two ways. In this paper, we investigate SoftRAN, the latest SDN solution for RAN, and SoftCell and MobileFlow, the latest solutions for CN. We also define a series of control functions for CROWD. Unlike in the other literature, we emphasize only softwaredefined cellular network solutions and specifications in order to provide possible research directions.展开更多
基金supported by the Natural Science Foundation of China under Grants U19B2025,62121001,and 62001347in part by Key Research and Development Program of Shaanxi(ProgramNo.2022ZDLGY05-02)in part by Young Talent Support Program of Xi’an Association for Science and Technology(No.095920221337).
文摘The unreasonable observation arrangements in the satellite operation control center(SOCC)may result in the observation data cannot be downloaded as scheduled.Meanwhile,if the operation instructions released by the satellite telemetry tracking center(STTC)for the on-board payloads are not injected on the specific satellites in time,the corresponding satellites cannot perform the observation operations as planned.Therefore,there is an urgent need to design an integrated instruction release,and observation task planning(I-IRO-TP)scheme by efficiently collaborating the SOCC and STTC.Motivated by this fact,we design an interaction mechanism between the SOCC and the STTC,where we first formulate the I-IRO-TP problem as a constraint satisfaction problem aiming at maximizing the number of completed tasks.Furthermore,we propose an interactive imaging task planning algorithm based on the analysis of resource distribution in the STTC during the previous planning periods to preferentially select the observation arcs that not only satisfy the requirements in the observation resource allocation phase but also facilitate the arrangement of measurement and control instruction release.We conduct extensive simulations to demonstrate the effectiveness of the proposed algorithm in terms of the number of completed tasks.
文摘Objective:To further evaluate the efficacy and safety of low-dose glucocorticoids combined with tacrolimus in the treatment of adult idiopathic membranous nephropathy(IMN)in a clinical setting.Methods:We carried out a single-center prospective study of 88 patients with IMN who were admitted into the Affiliated Hospital of Hebei University from January 2019 to December 2021,and the participants were divided into two groups based on their serum anti-PLA2R antibody levels:the negative group and the positive group.46 patients were positive for anti-PLA2R antibodies and 42 were negative.Results:After 6 months of treatment,the serum albumin,cholesterol,and 24h urine protein quantification in the anti-PLA2R negative group improved more significantly compared to the positive group(P<0.05);after 6 months of treatment,the remission rate of the positive group was significantly lower than that of the negative group,and(P<0.05);Conclusion:After treatment with tacrolimus combined with low-dose glucocorticoids,patients with idiopathic membranous nephropathy who were tested positive for anti-PLA2R antibodies had a higher overall remission rate compared those who were tested negative for serum anti-PLA2R antibodies.
基金supported in part by the National Key R&D Program of China under Grant 2020YFB1806100in part by the Natural Science Foundation of China under Grants U19B2025, 62121001, 62001347, and 61801361。
文摘The rapid development and continuous updating of the mega satellite constellation(MSC)have brought new visions for the future 6G coverage extension, where the global seamless signal coverage can realize ubiquitous services for user terminals. However, global traffic demands present nonuniform characteristics. Therefore, how to ensure the on-demand service coverage for the specific traffic demand, i.e., the ratio of traffic density to service requirement per unit area, is the core issue of 6G wireless coverage extension exploiting the MSC. To this regard, this paper first discusses the open challenges to reveal the future direction of 6G wireless coverage extension from the perspective of key factors affecting service coverage performance, i.e., the network access capacity, space segment capacity and their matchingrelationship. Furthermore, we elaborate on the key factors affecting effective matchings of the aforementioned aspects, thereby improving service coverage capability.
基金supported in part by the Natural Science Foundation of China(61725103,61701363,61931005,and 91638202)in part by Young Elite Scientists Sponsorship Program by CAST+1 种基金in part by the Key Industry Innovation Chain of Shaanxi under Grant 2017ZDCXL-GY-04-04in part by Fundamental Research Funds for the Central Universities。
文摘For received signal strength(RSS)fingerprint based indoor localization approaches,the localization accuracy is significantly influenced by the RSS variance,device heterogeneity and environment complexity.In this work,we present a high-adaptability indoor localization(HAIL)approach,which leverages the advantages of both relative RSS values and absolute RSS values to achieve robustness and accuracy.Particularly,a backpropagation neural network(BPNN)is devised in HAIL to measure the fingerprints similarities based on absolute RSS values.With this aid,the characteristics of the applied area could be specially learned such that HAIL could be adaptive to different environments.The experiments demonstrate that HAIL achieves high localization accuracy with the average localization error of 0.87 m in the typical environments.Moreover,HAIL has the minimum amount of large errors and decreases the average localization error by about 30%~50%compared with the existing approaches.
基金supported by the National Natural Science Foundation of China (Grant No. 41330423, 41420104006 & 41530426 )the International Partnership Program of Chinese Academy of Sciences under Grant No.134111KYSB20160031
文摘Climate system models are useful tools for understanding the interactions among the components of the climate system and predicting/projecting future climate change. The development of climate models has been a central focus of the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences(LASG/IAP) since the establishment of the laboratory in 1985. In China, many pioneering component models and fully coupled models of the climate system have been developed by LASG/IAP. The fully coupled climate system developed in the recent decade is named FGOALS(Flexible Global Ocean-Atmosphere-Land System Model). In this paper, an application-oriented review of the LASG/IAP FGOALS model is presented. The improved model performances are demonstrated in the context of cloud-radiation processes, Asian monsoon, ENSO phenomena, Atlantic Meridional Overturning Circulation(AMOC) and sea ice. The FGOALS model has contributed to both CMIP5(Coupled Model Intercomparison Project-phase 5) and IPCC(Intergovernmental Panel on Climate Change) AR5(the Fifth Assessment Report). The release of FGOALS data has supported the publication of nearly 500 papers around the world. The results of FGOALS are cited ~106 times in the IPCC WG1(Working Group 1) AR5. In addition to the traditional long-term simulations and projections, near-term decadal climate prediction is a new set of CMIP experiment, progress of LAGS/IAP in the development of nearterm decadal prediction system is reviewed. The FGOALS model has supported many Chinese national-level research projects and contributed to the national climate change assessment report. The crucial role of FGOALS as a modeling tool for supporting climate sciences is highlighted by demonstrating the model's performances in the simulation of the evolution of Earth's climate from the past to the future.
基金supported by the National Natural Science Foundation of China(62101415)the Guangdong Basic and Applied Basic Research Foundation(2020A1515110757).
文摘Recently cellular networks have been densely and heterogeneously deployed indoors and outdoors to expand the network capacity,and thus the in-building propagation loss and the transmit power diversity of access points will exacerbate link heterogeneity and result in partial unidirectional strong interference.To make full use of the strong interference feature,we propose the successive interference cancellation and alignment(SICA)scheme in the K-user interference channel with partial unidirectional strong interference.SICA is designed to transmit two kinds of data streams simultaneously,the alignment streams and superposition streams.The alignment streams will follow the interference alignment criterion to maintain the optimal degrees of freedom(DoF)performance;the superposition streams are handled via successive interference cancellation at all the strongly interfered receivers to improve the overall achievable rate.The joint transceiver designs for SICA is modeled as a weighted sum rate(WSR)maximization problem,and then can be alternately solved for a local optimum according to the optimality equivalence between WSR and its corresponding weighted mean square error(WMMSE)problem.Simulation results have confirmed the sum rate improvement and DoF optimality of the proposed SICA scheme.
基金supported in part by the Natural Science Foundation of China under Grant U19B2025,Grant 61725103,Grant 61701363,Grant 61931005,and Grant 62001347.
文摘The efficient antenna scheduling strategy for data relay satellites(DRSs)is essential to optimize the throughput or delay of the satellite data relay network.However,these two objectives conflict with each other since the user satellites(USs)with higher priorities take up more transmission time of DRSs’antennas for greater throughput but the USs storing more packets cause a severer waiting delay to the whole network.To balance the conflicting metrics for meeting the delay-throughput integrated requirements,we formulate the antenna scheduling as a stochastic non-convex fractional programming,which is challenging to be solved.For the tractability,we equivalently transform the fractional programming to a parametric problem and implement the Lyapunov drift to guarantee the constraint of mean rate stability.By proposing a delay and throughput tradeoff based antenna scheduling algorithm,we further transform the parametric problem to a solvable weight matching problem.Simulation results reveal the feasible region of the preference control parameter for integrated QoS cases and its variation relationship with network delay and throughput.
基金supported by the joint research projects entitled “Observing and Modelling Study on Spatial and Temporal Variation of Radiation Budget and PAR in Regional Scale” and “Evaluation on Detailed Agro-climatic Potential Productivity and Effects of Climate Change in Northeast China” (Grant No.CCSF201313)
文摘SUNFLUX is a fast parameterization scheme for determination of the solar radiation at the Earth's surface. In this paper, SUNFLUX is further modified in the treatment of aerosols. A new aerosol parameterization scheme is developed for five aerosol species. Observational data from Baseline Surface Radiation Network (BSRN), Surface Radiation Budget Network (SURFRAD) and Aerosol Robotic Network (AERONET) stations are used to evaluate the accuracy of the original and modified SUNFLUX schemes. General meteorological data are available at SURFRAD stations, but not at BSRN stations. Therefore, the total precipitable water content and aerosol data are obtained from AERONET stations. Fourteen stations are selected from both BSRN and AERONET. Cloud fraction data from MODIS are further used to screen the cloud. Ten-year average aerosol mixing ratios simulated by the CAM-chem system are used to calculate the fractions of aerosol optical depth for each aerosol species, and these fractions are further used to convert the observed total aerosol optical depth into the components of individual species for use in the evaluations. The proper treatment of multiple aerosol types in the model is discussed. The evaluation results using SUNFLUX with the new aerosol scheme, in terms of the BSRN dataset, are better than those using the original aerosol scheme under clear-sky conditions. However, the results using the SURFRAD dataset are slightly worse, attributable to the differences in the input water vapor and aerosol optical depth. Sensitivity tests are conducted to investigate the error response of the SUNFLUX scheme to the errors in the input variables.
基金supported in part by National Key Research and Development Program of China (Grant No. 2020YFB1807001)in part by Natural Science Foundation of China (Grant No. 62171344, 62121001, 61725103, 61931005)+1 种基金in part by Young Elite Scientists Sponsorship Program by CASTin part by Key Industry Innovation Chain of Shaanxi (Grant No. 2022ZDLGY05-01, 2022ZDLGY05-06)
文摘Due to flexible deployment,unmanned aerial vehicle(UAV)mounted aerial access points are capable of expanding the coverage capabilities of existing terrestrial base stations(TBSs).Different from TBSs,however,UAV access points(UAPs)are of high mobility in horizontal and vertical dimensions,which may deteriorate the coverage performance.Worsestill,the mobility of UAPs would as well increase the pressure of wireless backhaul.In this light,we investigate the performance of the cache-enabled UAV communications network(CUCN)in terms of network spatial throughput(ST)by analyzing the line of sight(LoS)connections and non-line of sight(NLoS)connections.It is found that the network ST is exponentially decreased with the square of UAP altitude.Furthermore,contrary to intuition,a large cache size may deteriorate the network ST when UAPs are over-deployed.The reason is that a large cache size increases the hit probability,which may increase the activation of UAPs and consequently result in complicated interference.Aiming to maximize the network ST,we optimize the cache strategy under limited backhaul.Remarkably,the results show that network ST could be substantially improved by the optimized cache strategy and the performance degeneration brought by UAP high mobility could be even eliminated especially when the UAP altitude is high.
文摘Delay Tolerant Networks (DTNs) is a dynamic topology network, in which connection durations of each link are variable and paths between two nodes are intermittent. Most of protocols which are widely used in traditional wireless network are not suitable for DTNs. DTN adopts store-and-forward mechanism to cope with the problem of intermittent path. With limited storage of each node, it is a challenge for scheduling nodes’ transmission to avoid overflow of nodes’ buffers. In this paper we propose an optimal transmission scheduling algorithm for DTN with nodes’ buffer constraints. The object of the optimal algorithm is to get maximum throughput. We also present an algorithm for obtaining suboptimal transmission schedules. Our solution is certified through simulation, and it is observed that our solution can improve network performance in the aspects of avoiding overflow and increasing network throughput.
基金supported in part by Natural Science Foundation of China(Grant No.62121001,62171344,61931005)in part by Young Elite Scientists Sponsorship Program by CAST+2 种基金in part by Key Industry Innovation Chain of Shaanxi(Grant No.2022ZDLGY0501,2022ZDLGY05-06)in part by Key Research and Development Program of Shannxi(Grant No.2021KWZ-05)in part by The Major Key Project of PCL(PCL2021A15)。
文摘In this paper,we reveal the fundamental limitation of network densification on the performance of caching enabled small cell network(CSCN)under two typical user association rules,namely,contentand distance-based rules.It indicates that immoderately caching content would significantly change the interference distribution in CSCN,which may degrade the network area spectral efficiency(ASE).Meanwhile,it is shown that content-based rule outperforms the distance-based rule in terms of network ASE only when small cell base stations(BSs)are sparsely deployed with low decoding thresholds.Moreover,it is proved that network ASE under distance-based user association serves as the upper bound of that under content-based rule in dense BS regime.To enable more spectrum-efficient user association in dense CSCN,we further optimize network ASE by designing a probabilistic content retrieving strategy based on distance-based rule.With the optimized retrieving probability,network ASE could be substantially enhanced and even increase with the growing BS density in dense BS regime.
基金supported by the National Key Research and Development Program of China[grant number 2018YFC1505706]the National Natural Science Foundation of China[grant numbers 91937302,91737306,41975109]the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDA17010105]。
文摘Objective:To determine the risk factors of infection in patients with nephrotic syndrome.Methods:A retrospective study was conducted on 155 patients with nephrotic syndrome under our department from January 2019 to December 2019.Among them,43 cases had infection,and the rate of infection was 27.74%.The risk factors of infection were analyzed.Results:Among the 155 patients with nephrotic syndrome,43 cases developed infection,including 3 cases of upper respiratory tract infection(6.98%),33 cases of lower respiratory tract infection(76.74%),3 cases of skin infection(6.97%),3 cases of urinary tract infection(6.97%),and 1 case of facial nerve infection(2.32%).Compared with the group without infection,the group with infection had lower serum albumin and immunoglobulin G(IgG)levels as well as higher serum creatinine and 24-hour urinary protein levels(P<0.05).Multivariate logistic regression analysis showed that decreased serum albumin(odds ratio[OR]=1.14;P<0.01)and IgG(OR=1.1;P<0.144)were independent risk factors for infection.Conclusion:Respiratory infection is the most common infection in nephrotic syndrome,and the decrease in serum albumin and IgG are independent risk factors for infection.
基金funded by the National Key Research and development Program of China (Grant No. 2017YFA0604004)the National Natural Science Foundation of China (Grant Nos. 91737306, U1811464, 41530426, 91837101, 41730963, and 91637312)
文摘The outputs of the Chinese Academy of Sciences(CAS) Flexible Global Ocean–Atmosphere–Land System(FGOALS-f3-L) model for the baseline experiment of the Atmospheric Model Intercomparison Project simulation in the Diagnostic,Evaluation and Characterization of Klima common experiments of phase 6 of the Coupled Model Intercomparison Project(CMIP6) are described in this paper. The CAS FGOALS-f3-L model, experiment settings, and outputs are all given. In total,there are three ensemble experiments over the period 1979–2014, which are performed with different initial states. The model outputs contain a total of 37 variables and include the required three-hourly mean, six-hourly transient, daily and monthly mean datasets. The baseline performances of the model are validated at different time scales. The preliminary evaluation suggests that the CAS FGOALS-f3-L model can capture the basic patterns of atmospheric circulation and precipitation well, including the propagation of the Madden–Julian Oscillation, activities of tropical cyclones, and the characterization of extreme precipitation. These datasets contribute to the benchmark of current model behaviors for the desired continuity of CMIP.
基金funded by the National Natural Science Foundation of China (Grant Nos. 91737306, 91637312, 41730963, 91837101, 91637208, 41530426)the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (Grant QYZDY-SSW-DQC018)
文摘The Chinese Academy of Sciences(CAS)Flexible Global Ocean Atmosphere Land System(FGOALS-f3-L)model datasets prepared for the sixth phase of the Coupled Model Intercomparison Project(CMIP6)Global Monsoons Model Intercomparison Project(GMMIP)Tier-1 and Tier-3 experiments are introduced in this paper,and the model descriptions,experimental design and model outputs are demonstrated.There are three simulations in Tier-1,with different initial states,and five simulations in Tier-3,with different topographies or surface thermal status.Specifically,Tier-3 contains four orographic perturbation experiments that remove the Tibetan Iranian Plateau,East African and Arabian Peninsula highlands,Sierra Madre,and Andes,and one thermal perturbation experiment that removes the surface sensible heating over the Tibetan Iranian Plateau and surrounding regions at altitudes above 500 m.These datasets will contribute to CMIP6’s value as a benchmark to evaluate the importance of long-term and short-term trends of the sea surface temperature in monsoon circulations and precipitation,and to a better understanding of the orographic impact on the global monsoon system over highlands.
文摘Software- defined networking (SDN) is a promising technology for next-generation networking and has attracted much attention from academics, network equipment manufacturer, network operators, and service providers. It has found center, and enterprise networks. applications in mobile, data The SDN architecture has a centralized, programmable control plane that is separate from the data plane. SDN also provides the ability to control and manage virtualized resources and networks without requiring new hardware technologies. This is a major shift in networking technologies.
基金funded by the National Natural Science Foundation of China (Grants 41675100, 91737306, and U1811464)
文摘Cloud dominates influence factors of atmospheric radiation, while aerosol–cloud interactions are of vital importance in its spatiotemporal distribution. In this study, a two-moment(mass and number) cloud microphysics scheme, which significantly improved the treatment of the coupled processes of aerosols and clouds, was incorporated into version 1.1 of the IAP/LASG global Finite-volume Atmospheric Model(FAMIL1.1). For illustrative purposes, the characteristics of the energy balance and cloud radiative forcing(CRF) in an AMIP-type simulation with prescribed aerosols were compared with those in observational/reanalysis data. Even within the constraints of the prescribed aerosol mass, the model simulated global mean energy balance at the top of the atmosphere(TOA) and at the Earth’s surface, as well as their seasonal variation, are in good agreement with the observational data. The maximum deviation terms lie in the surface downwelling longwave radiation and surface latent heat flux, which are 3.5 W m-2(1%) and 3 W m-2(3.5%), individually. The spatial correlations of the annual TOA net radiation flux and the net CRF between simulation and observation were around 0.97 and 0.90, respectively. A major weakness is that FAMIL1.1 predicts more liquid water content and less ice water content over most oceans. Detailed comparisons are presented for a number of regions, with a focus on the Asian monsoon region(AMR). The results indicate that FAMIL1.1 well reproduces the summer–winter contrast for both the geographical distribution of the longwave CRF and shortwave CRF over the AMR. Finally, the model bias and possible solutions, as well as further works to develop FAMIL1.1 are discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.41991283 and 42005014)College Students’Enterprise and Entrepreneurship Education Program of NUIST(Grant No.201910300095Y)。
文摘In this study, variation in the frequency of thermal discomfort days over China during the period of 1961-2014,including heat discomfort days(HDDs) and cold discomfort days(CDDs), and the influence of external forcings on it are discussed. HDDs are the conditions of overheating and overhumidity(represented by humidity index), and CDDs reflect the dangers from cold temperatures and winds(represented by wind chill index). Observations show significant increases(decreases) in the frequency of HDDs(CDDs) over China from 1961 to 2014, with clear regional distinctions. The historical ALL and greenhouse gas(GHG) simulations can sufficiently reproduce the spatial patterns of the observational trend in the frequency of both HDDs and CDDs over China. Further, the impacts of GHG and anthropogenic forcings on the HDDs(CDDs) are detectable over China, except for central and eastern China, based on the optimal fingerprinting method. GHG forcing is identified as a dominant factor for the observational changes in the frequency of HDDs over southern China;GHG and anthropogenic forcings have dominant effects on the variation in the frequency of CDDs over southwestern China. Although trends in the frequency of HDDs and CDDs in historical aerosol forcing simulations seems to be opposite to observations, an aerosol signal fails to be detected. Natural forcing contributes to the observational variation in the frequency of HDDs over northwestern China. In addition, the future projections of thermal discomfort days indicate that Chinese residents will face more threats of heat discomfort and fewer threats of cold discomfort in the future under global warming.
文摘The emergency relating to software-defined networking (SDN), especially in terms of the prototype associated with OpenFlow, provides new possibilities for innovating on network design. Researchers have started to extend SDN to cellular networks. Such new programmable architecture is beneficial to the evolution of mobile networks and allows operators to provide better services. The typical cellular network comprises radio access network (RAN) and core network (CN); hence, the technique roadmap diverges in two ways. In this paper, we investigate SoftRAN, the latest SDN solution for RAN, and SoftCell and MobileFlow, the latest solutions for CN. We also define a series of control functions for CROWD. Unlike in the other literature, we emphasize only softwaredefined cellular network solutions and specifications in order to provide possible research directions.