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Trust Score-Based Malicious Vehicle Detection Scheme in Vehicular Network Environments

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Computers, Materials & Continua 2024年第11期81卷 2517-2545页

作者： Wenming Wang zhiquan liu Shumin Zhang Guijiang liu School of Computer and Information Anqing Normal UniversityAnqing246133China State Key Laboratory for Novel Software Technology Nanjing UniversityNanjing210023China Yunnan Key Laboratory of Service Computing Yunnan University of Finance and EconomicsKunming650221China

Advancements in the vehicular network technology enable real-time interconnection,data sharing,and intelligent cooperative driving among ***,malicious vehicles providing illegal and incorrect information can compromise the interests of vehicle *** mechanisms serve as an effective solution to this *** recent years,many researchers have incorporated blockchain technology to manage and incentivize vehicle nodes,incurring significant overhead and storage requirements due to the frequent ingress and egress of vehicles within the *** this paper,we propose a distributed vehicular network scheme based on trust ***,the designed architecture partitions multiple vehicle regions into ***,cloud supervision systems(CSSs)verify the accuracy of the information transmitted by ***,the trust scores for vehicles are calculated to reward or penalize them based on the trust evaluation *** proposed scheme demonstrates good scalability and effectively addresses the main cause of malicious information distribution among *** theoretical and experimental analysis show that our scheme outperforms the compared schemes.

关键词： Distributed trust mechanism vehicular network privacy protection

VKSE-MO: verifiable keyword search over encrypted data in multi-owner settings

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Science China(Information Sciences) 2017年第12期60卷 192-206页

作者： Yinbin MIAO Jianfeng MA Ximeng liu Junwei ZHANG zhiquan liu School of Cyber Engineering Xidian University School of Information Systems Singapore Management University

Searchable encryption(SE) techniques allow cloud clients to easily store data and search encrypted data in a privacy-preserving manner, where most of SE schemes treat the cloud server as ***, in practice, the cloud server is a semi-honest-but-curious third-party, which only executes a fraction of search operations and returns a fraction of false search results to save its computational and bandwidth resources. Thus, it is important to provide a results verification method to guarantee the correctness of the search results. Existing SE schemes allow multiple data owners to upload different records to the cloud server,but these schemes have very high computational and storage overheads when applied in a different but more practical setting where each record is co-owned by multiple data owners. To address this problem, we develop a verifiable keyword search over encrypted data in multi-owner settings(VKSE-MO) scheme by exploiting the multisignatures technique. Thus, our scheme only requires a single index for each record and data users are assured of the correctness of the search results in challenging settings. Our formal security analysis proved that the VKSE-MO scheme is secure against a chosen-keyword attack under a random oracle model. In addition, our empirical study using a real-world dataset demonstrated the efficiency and feasibility of the proposed scheme in practice.

关键词： chosen-keywork attack efficiency and feasibility multi-owner settings result verification searchable encryption

An approach to quality assessment for web service selection based on the analytic hierarchy process for cases of incomplete information

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Science China(Information Sciences) 2015年第12期58卷 75-88页

作者： GAO Cong MA JianFeng liu zhiquan MA XinDi School of Computer Science and Technology Xidian University

Since web services intended for the same application environment tend to be functionally homogeneous, researchers have turned to their non-functional aspects in order to constructively compare web services and choose an appropriate one. In general, quality of service is very important to users. Many schemes that consider quality assessment have been proposed for web service selection. With the increasing number of qualityrelated attributes, an effective quality assessment method needs satisfactory scalability. Schemes based on the analytic hierarchy process(AHP) meet this requirement. However, prevalent methods in this vein overlook the fact that the traditional AHP needs a complete judgment matrix. In practice, all the information needed to construct a judgment matrix is often unavailable for a variety of reasons, due to which certain judgments cannot be made. In this paper, for an incomplete judgment matrix, we propose an improved AHP approach to consistency verification and the subsequent ordering. Our method can deal with situations where information is insufficient,and inherits all the merits of the traditional AHP approach. A case study establishes the effectiveness of our proposed method.

关键词： incomplete information quality assessment analytic hierarchy process(AHP) web services qual ity of service selection

Evaluation of Daily Precipitation Product in China from the CMA Global Atmospheric Interim Reanalysis

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Journal of Meteorological Research 2020年第1期34卷 117-136,1-4页

作者： Chunxiang LI Tianbao ZHAO Chunxiang SHI zhiquan liu Key Laboratory of Regional Climate-Environment Research for East Asia Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029 National Meteorological Information Center China Meteorological AdministrationBeijing 100081

The China Meteorological Administration(CMA)recently produced a CMA Global Atmospheric Interim Reanalysis(CRAI)dataset for the years 2007–2016.A comprehensive evaluation of the ability of CRAI to capture the spatiotemporal variability of observed precipitation,in terms of both mean states and extreme indicators over China,is *** are made with other current reanalysis datasets,namely,the ECMWF interim reanalysis(ERAI),Japanese 55-yr reanalysis(JRA55),NCEP Climate Forecast System Reanalysis(CFSR),and NASA Modern-Era Retrospective analysis for Research and Applications version 2(MERRA2),as well as NCEP Climate Prediction Center(CPC)*** results show that,for daily variations of rainfall during warm seasons in eastern China,CRAI and CFSR overestimate the precipitation of the main rain belt,while the overestimation is confined to the area south of 25°N in JRA55 but north of 24°N in MERRA2;whereas ERAI tends to underestimate the precipitation in most regions of eastern *** extreme metrics,the total amount of precipitation on days where daily precipitation exceeds the 95 th percentile(R95 pTOT)and the number of consecutive dry days(CDDs)in one month,are examined to assess the performance of reanalysis *** terms of extreme events,CRAI,ERAI,and JRA55 tend to underestimate the R95 pTOT in most of eastern China,whereas more frequent extreme rainfall can be found in most regions of China in both CFSR and MERRA2;and all of the reanalyses underestimate the *** the reanalysis products,CRAI and JRA55 show better agreement with the observed R95 pTOT than the other datasets,with fewer biases,higher correlation coefficients,and much more similar linear trend patterns,while ERAI stands out in better capturing the amount and temporal variations of the observed CDDs.

关键词： China Meteorological Administration(CMA) the CMA Global Atmospheric Interim Reanalysis(CRAI) precipitation daily

Assimilating All-sky Infrared Radiances from Himawari-8 Using the 3DVar Method for the Prediction of a Severe Storm over North China

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Advances in Atmospheric Sciences 2021年第4期38卷 661-676页

作者： Dongmei XU zhiquan liu Shuiyong FAN Min CHEN Feifei SHEN The Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing 210044China Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province Chengdu 610225China National Center for Atmos.Res. BoulderColorado80301USA Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089China

Although radar observations capture storm structures with high spatiotemporal resolutions, they are limited within the storm region after the precipitation formed. Geostationary satellites data cover the gaps in the radar network prior to the formation of the precipitation for the storms and their environment. The study explores the effects of assimilating the water vapor channel radiances from Himawari-8 data with Weather Research and Forecasting model data assimilation system(WRFDA) for a severe storm case over north China. A fast cloud detection scheme for Advanced Himawari imager(AHI)radiance is enhanced in the framework of the WRFDA system initially in this study. The bias corrections, the cloud detection for the clear-sky AHI radiance, and the observation error modeling for cloudy radiance are conducted before the data assimilation. All AHI radiance observations are fully applied without any quality control for all-sky AHI radiance data assimilation. Results show that the simulated all-sky AHI radiance fits the observations better by using the cloud dependent observation error model, further improving the cloud heights. The all-sky AHI radiance assimilation adjusts all types of hydrometeor variables, especially cloud water and precipitation snow. It is proven that assimilating all-sky AHI data improves hydrometeor specifications when verified against the radar reflectivity. Consequently, the assimilation of AHI observations under the all-sky condition has an overall improved impact on both the precipitation locations and intensity compared to the experiment with only conventional and AHI clear-sky radiance data.

关键词： Himawari-8 data assimilation all-sky storm case

Bias Adjustment and Analysis of Chinese Daily Historical Radiosonde Temperature Data

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Journal of Meteorological Research 2021年第1期35卷 17-31页

作者： Zhe CHEN Zijiang ZHOU zhiquan liu Qinglei LI Xiaoling ZHANG National Meteorological Information Center China Meteorological AdministrationBeijing 100081China National Center for Atmospheric Research BoulderColorado 80301USA Beijing Meteorological Information Center Beijing Meteorological ServiceBeijing 100089China

The discontinuities in historical Chinese radiosonde datasets are attributed to artificial errors. In order to reflect more realistically basic conditions of the atmosphere over China and provide more reasonable radiosonde data as input to climate change analysis and to atmospheric reanalysis data assimilation systems, this paper proposes a scheme to identify breakpoints and adjust biases in daily radiosonde observations. The ongoing ECMWF Re Analysis-Interim(ERA-Interim) 12-h forecasts are used as reference series in the scheme, complemented by the ECMWF Twentieth Century Reanalysis(ERA-20 C). A series of breakpoint identification schemes are developed and combined with metadata to detect breakpoints. The Quantile-Matching(QM) method is applied to test and adjust daily radiosonde data on 12 mandatory pressure levels collected at 80 sounding stations during 1979–2013. The adjusted temperatures on mandatory levels are interpolated to significant levels for temperature adjustment on these levels. The adjustment scheme not only solves the data discontinuity problem caused by changes in observational instruments and bias correction methods, but also solves the discontinuity problem in the 1200 minus 0000 UTC temperature time series on mandatory levels at individual sounding stations. Before the adjustment, obvious discontinuities can be found in the deviation field between the raw radiosonde data and ERA-Interim reanalysis with relatively large deviations before 2001. The deviation discontinuity is mainly attributed to the nationwide upgrade of the radiosonde system in China around 2001. After the adjustment, the time series of deviations becomes more continuous. In addition, compared with the adjusted temperature data on mandatory levels over 80 radiosonde stations in China contained in the Radiosonde Observation Correction Using Reanalyses(RAOBCORE) 1.5, the dataset adjusted by the method proposed in the present study exhibits higher quality than RAOBCORE 1.5, while d

关键词： daily radiosonde temperature data mandatory levels significant levels bias adjustment

Evaluation of drinking water treatment combined filter backwash water recycling technology based on comet and micronucleus assay

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Journal of Environmental Sciences 2016年第4期28卷 61-70页

作者： Ting Chen Yongpeng Xu zhiquan liu Shijun Zhu Wenxin Shi Fuyi Cui State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology School of Municipal and Environmental Engineering Harbin Institute of Technology

Based on the fact that recycling of combined filter backwash water（CFBW）directly to drinking water treatment plants（WTP）is considered to be a feasible method to enhance pollutant removal efficiency,we were motivated to evaluate the genotoxicity of water samples from two pilot-scale drinking water treatment systems,one with recycling of combined backwash water,the other one with a conventional *** integrated approach of the comet and micronucleus（MN）assays was used with zebrafish（Danio rerio）to investigate the water genotoxicity in this *** total organic carbon（TOC）,dissolved organic carbon（DOC）,and trihalomethane formation potential（THMFP）,of the recycling process were lower than that of the conventional *** the results showed that there was no statistically significant difference（P〉0.05）between the conventional and recycling processes,and indicated that the genotoxicity of water samples from the recycling process did not accumulate in 15 day continuous recycling *** was worth noting that there was correlation between the concentrations of TOC,DOC,UV（254）,and THMFPs in water and the DNA damage score,with corresponding R^2 values of 0.68,0.63,0.28,and ***,both DNA strand breaks and MN frequency of all water samples after disinfection were higher than that of water samples from the two treatment units,which meant that the disinfection by-products（DBPs）formed by disinfection could increase the DNA *** the comet and MN tests suggest that the recycling process did not increase the genotoxicity risk,compared to the traditional process.

关键词： Combined filter backwash water Drinking water treatment Genotoxicity Comet assay Micronucleus

Active device detection and performance analysis of massive non-orthogonal transmissions in cellular Internet of Things

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Science China(Information Sciences) 2022年第8期65卷 164-181页

作者： Donghong CAI Pingzhi FAN Qiuyun ZOU Yanqing XU Zhiguo DING zhiquan liu College of Cyber Security Jinan University Institute of Mobile Communications Southwest Jiaotong University School of Information and Communication Engineering Beijing University of Posts and Telecommunications School of Science and Engineering The Chinese University of Hong Kong The University of Science and Technology of China School of Electrical and Electronic Engineering The University of Manchester

This paper investigates multiple access schemes for uplink and downlink transmissions in cellular networks with massive Internet of Things(IoT) devices. Recall that single-carrier frequency division multiple access and orthogonal frequency division multiple access, which are orthogonal multiple access(OMA) schemes, have been conventionally adopted for uplink and downlink transmissions in narrow-band IoT, respectively. Unlike these OMA schemes, we propose two non-orthogonal multiple access(NOMA)schemes for cellular IoT with short-packet transmissions. Especially, a generalized expectation consistent signal recovery-based algorithm is proposed to estimate active devices, channel state information and data in uplink transmission, where all of the active devices are allowed to transmit their pilots and data through the same resource block without authorization. On the other hand, the active devices estimated during uplink transmission are grouped for downlink transmission with a trade-off between performance and detection complexity. Additionally, the data error rates are analysed for both uplink and downlink transmissions with low-resolution analog-to-digital converters(ADCs), where the effects of critical parameters such as the estimation error, ADC bits, packet length, and message bits are revealed. Both simulation and analytical results are provided to demonstrate the excellent performance of the proposed NOMA schemes and algorithms, especially for active device, channel, and data estimations. More importantly, the obtained results show that the data error rate performance of downlink NOMA is superior to that of OMA when the message bits of devices in one group are selected following the proposed strategy.

关键词： massive connections non-orthogonal multiple access active device detection short-packet.

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Effect of filter-feeding fish silver carp on phytoplankton species and size distribution in surface water:A field study in water works

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Journal of Environmental Sciences 2010年第2期22卷 161-167页

作者： Hua Ma Fuyi Cui zhiquan liu Zhenqiang Fan Wenjie He Peijun Yin State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin 150090 China Tianjin Waterworks Group Co. Ltd. Tianjin 300040 China

Silver carp were introduced into the pre-sedimentation pond to control excessive phytoplankton in raw water. The effectiveness of the filter-feeding silver carp on phytoplankton control and the effect of silver carp on phytoplankton community were investigated. The results showed that Microcystis could be effectively removed by silver carp stocked in the pre-sedimentation pond, and simultaneously, the concentration of single-cell phytoplankton increased obviously. The difference in phytoplankton species and single- cell phytoplankton size between in the water and in the gut of silver carp indicated that phytoplankton smaller than 5 μm, such as Chamydomonas and Platymonas, were almost not be filtered by silver carp, phytoplankton with the size between 5 and 20μm could be partly filtered, and large size phytoplankton, mainly colony-forming Microcystis could be filtered almost completely. These filter- feeding characteristics directly caused the phytoplankton size distribution biased toward miniaturization. Therefore, this biological treatment using silver carp could be applied only to deal with groups of Microcystis-dominated eutrophic water, and was not appropriate in water bodies where single-cell micro phytoplankton were dominant. Especially when silver carp are used in water treatment, a cautious attitude should be taken based on the evaluation of phytoplankton biomass and species structure features in raw water.

关键词： phytoplankton control silver carp Microcystis single-cell micro phytoplankton