Inferring Locations of Mobile Devices from Wi-Fi Data

Mobile phones are becoming a primary platform for information access. A major aspect of ubiquitous computing is context-aware applications which collect information about the environment that the user is in and use this information to provide better service and improve user experience. Location awareness makes certain applications possible, e.g., recommending nearby businesses and tracking estimated routes. An Android application is able to collect useful Wi-Fi information without registering a location listener with a network-based provider. We passively collected the data of the IDs of Wi-Fi access points and the received signal strengths. We developed and implemented an algorithm to analyse the data;and designed heuristics to infer the location of the device over time—all without ever connecting to the network thus maximally preserving the privacy of the user.

一种Wi-Fi RTT/数据驱动惯性导航行人室内定位方法

为了研究基于智能手机的行人室内定位方法,并提高其精度,本文提出了一种基于Wi-Fi往返时间(RTT)、惯性测量单元(IMU)的定位系统。该方法主要包括3部分:(1)使用扩展卡尔曼滤波融合测距信息的Wi-Fi RTT室内定位方法;(2)适用于多手机使用模式的航位推算方法,该方法基于长短时记忆模型(LSTM)建立神经网络模型,预测行人运动速度及航向;(3)基于误差状态卡尔曼滤波的Wi-Fi RTT/数据驱动惯性导航融合定位方法,进一步提高定位精度。试验结果表明,与单一的基于Wi-Fi RTT方法和数据驱动惯性导航方法相比,本文方法的平均定位精度提升了10%~20%。

基于Wi-Fi指纹且计算外包的室内定位隐私保护方案

为了解决室内定位中用户和服务器双方的隐私保护问题,提出了一种在使用Paillier加密的过程中将部分计算外包给云服务器的方案,这不仅保护了用户和定位服务器的隐私,而且避免了产生过大的计算和通信开销。该方案的主要思想是服务器先在离线阶段建立指纹数据库,在线阶段用户将k匿名算法和Paillier加密结合,将加密后的Wi-Fi指纹发送给定位服务器,服务器对接收到的Wi-Fi指纹和数据库指纹进行聚合处理,然后外包给云服务器进行解密和距离计算,最终得到定位结果。理论分析和实验结果表明了所提方案的安全性、有效性和实用性。

基于Wi-Fi感知的多用户身份识别研究

随着无线感知技术的发展,基于Wi-Fi的身份识别研究在人机交互和家居安防等领域备受关注。尽管基于Wi-Fi信号的身份识别已经取得了初步的成功,但是目前主要适用于用户独立行为场景,并发行为下的多用户身份识别仍然面临着一系列挑战,包括用户之间的相互干扰以及模型鲁棒性差等问题。因此,提出了一种并发行为下多用户身份识别系统Wiblack,其核心思想是训练一个多分支深度神经网络(Wiblack-Net)来提取每个单用户的独特特征。首先,利用主干网络提取多用户之间的共同特征;然后,为每个用户分配一个二分类器以此判断给定群体中是否存在目标用户,在此基础上基于并发行为实现多个用户身份识别。此外,将Wiblack与多个独立的二分类模型和单个多分类模型进行对比实验,对运行效率和系统性能进行分析。实验结果显示,在同时识别3个用户身份时,Wibalck平均准确率达到了92.97%,平均精确度为93.71%,平均召回率为93.24%,平均F1值为92.43%。

基于Wi-Fi Sensing的无感检测技术

随着智能家居的推广普及,对于移动物体的行为感知成为热点技术。相比于传统的信息检测技术,新型的基于Wi-Fi信号的设备无关被动入侵检测,能够在无需用户做任何干预也不影响人员隐私安全的情况下实现对于行为的检测判断,这和使用摄像头或红外检测形成显著差异,成为研究热点。该文基于Wi-Fi芯片平台采集物理层信道状态信息,构建与移动载体信息相关的检测模型,结合大数据分析和智能算法,给出相关的实现方案,并基于实验验证实现从无线信道中捕捉波形特征,验证方案的有效性,结合结果分析也为后续精度的进一步提升提供改进方向。

基于Wi-Fi的医疗设备物联网采集装置设计

为解决医疗设备运行数据、故障数据的采集,设计一种基于无线网络Wi-Fi的医疗设备物联网采集装置。该采集装置的设计基于STM32F407的32位微控制器与ESP8266无线模组集成的,通过Wi-Fi进行通讯的物联网数据采集装置。通过该采集装置,在配置波特率后,能够实现通过串口等数据接口读取医疗设备的运行数据,并通过无线模组进行配网,连接到楼层网络无线接入点(AP)后,实现与物联网平台服务器的数据交互,达到对医疗设备的动态管理。装配应用该采集装置,可实现在物联网平台软件对呼吸机、高频电刀、监护仪、血液透析机等设备的数据采集应用,解决无法实现无线通讯的医疗设备的数据通讯问题,在获取通讯协议的前提下,可适配于较多该类型医疗设备的数据采集及数据发送功能,实现医院对该类型医疗设备的动态管理。

基于re3data的中英科学数据仓储平台对比研究

以re3data为数据获取源,选取中英两国406个科学数据仓储为研究对象,从分布特征、责任类型、仓储许可、技术标准及质量标准等5个方面、11个指标对两国科学数据仓储的建设情况进行对比分析,试图为我国数据仓储的可持续发展提出建议:广泛联结国内外异质机构,推进多学科领域的交流与合作,有效扩充仓储许可权限与类型,优化技术标准的应用现况,提高元数据使用的灵活性。

基于Wi-Fi信道状态信息的坐姿监测方法

[目的]针对现有的坐姿监测方法存在的接触式、隐私性低、成本高、部署不方便等问题对坐姿监测方法进行研究.[方法]提出基于Wi-Fi信道状态信息的坐姿监测方法.该方法在不同坐姿下采集商用路由器的Wi-Fi信道状态信息,结合卷积神经网络和长短期记忆神经网络建立坐姿分类模型,融合采样窗口内信道状态信息的幅值和相位数据,并充分提取数据的空间和时间特征,提高坐姿分类精度.在对原始相位数据进行预处理时,提出了近邻子载波差值阈值补偿方法,有效地解决了不同子载波的相位旋绕不同步的问题.[结果]搭建坐姿监测环境,对办公或学习场景下的5种常见坐姿进行分类.实验证明,该坐姿监测方法对坐姿分类有较高的准确率,对所有坐姿分类的平均准确率达到91.23%.[结论]本文提出的基于Wi-Fi信道状态信息的坐姿监测方法,具有非接触式、隐私性高、成本低、部署方便等特点,且对坐姿分类准确率高,在坐姿监测系统的研究上具有一定的实用价值.

Data Secure Storage Mechanism for IIoT Based on Blockchain

With the development of Industry 4.0 and big data technology,the Industrial Internet of Things(IIoT)is hampered by inherent issues such as privacy,security,and fault tolerance,which pose certain challenges to the rapid development of IIoT.Blockchain technology has immutability,decentralization,and autonomy,which can greatly improve the inherent defects of the IIoT.In the traditional blockchain,data is stored in a Merkle tree.As data continues to grow,the scale of proofs used to validate it grows,threatening the efficiency,security,and reliability of blockchain-based IIoT.Accordingly,this paper first analyzes the inefficiency of the traditional blockchain structure in verifying the integrity and correctness of data.To solve this problem,a new Vector Commitment(VC)structure,Partition Vector Commitment(PVC),is proposed by improving the traditional VC structure.Secondly,this paper uses PVC instead of the Merkle tree to store big data generated by IIoT.PVC can improve the efficiency of traditional VC in the process of commitment and opening.Finally,this paper uses PVC to build a blockchain-based IIoT data security storage mechanism and carries out a comparative analysis of experiments.This mechanism can greatly reduce communication loss and maximize the rational use of storage space,which is of great significance for maintaining the security and stability of blockchain-based IIoT.

Enhanced prediction of anisotropic deformation behavior using machine learning with data augmentation

Mg alloys possess an inherent plastic anisotropy owing to the selective activation of deformation mechanisms depending on the loading condition.This characteristic results in a diverse range of flow curves that vary with a deformation condition.This study proposes a novel approach for accurately predicting an anisotropic deformation behavior of wrought Mg alloys using machine learning(ML)with data augmentation.The developed model combines four key strategies from data science:learning the entire flow curves,generative adversarial networks(GAN),algorithm-driven hyperparameter tuning,and gated recurrent unit(GRU)architecture.The proposed model,namely GAN-aided GRU,was extensively evaluated for various predictive scenarios,such as interpolation,extrapolation,and a limited dataset size.The model exhibited significant predictability and improved generalizability for estimating the anisotropic compressive behavior of ZK60 Mg alloys under 11 annealing conditions and for three loading directions.The GAN-aided GRU results were superior to those of previous ML models and constitutive equations.The superior performance was attributed to hyperparameter optimization,GAN-based data augmentation,and the inherent predictivity of the GRU for extrapolation.As a first attempt to employ ML techniques other than artificial neural networks,this study proposes a novel perspective on predicting the anisotropic deformation behaviors of wrought Mg alloys.

基于通感一体化的Wi-Fi卸载匹配算法

针对目前移动数据流量激增所导致的通感一体化无线通信网络系统中的拥塞和过载问题,提出一种基于通感一体化的Wi-Fi卸载匹配算法。首先,基于信息论综合考虑系统的通信吞吐量和感知互信息量,定义系统的效用函数,在满足用户QoS的同时最大化系统的总效用;其次,基于图论的思想建立Wi-Fi信道分配算法为每个Wi-Fi接入点分配信道,并将用户的接入选择问题建立为具有外部性的多对一匹配博弈模型。仿真结果表明,所设计的卸载策略能够提高系统的总效用,缓解基站处的数据压力。

ST-Map:an Interactive Map for Discovering Spatial and Temporal Patterns in Bibliographic Data

Getting insight into the spatiotemporal distribution patterns of knowledge innovation is receiving increasing attention from policymakers and economic research organizations.Many studies use bibliometric data to analyze the popularity of certain research topics,well-adopted methodologies,influential authors,and the interrelationships among research disciplines.However,the visual exploration of the patterns of research topics with an emphasis on their spatial and temporal distribution remains challenging.This study combined a Space-Time Cube(STC)and a 3D glyph to represent the complex multivariate bibliographic data.We further implemented a visual design by developing an interactive interface.The effectiveness,understandability,and engagement of ST-Map are evaluated by seven experts in geovisualization.The results suggest that it is promising to use three-dimensional visualization to show the overview and on-demand details on a single screen.

A phenology-based vegetation index for improving ratoon rice mapping using harmonized Landsat and Sentinel-2 data

Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while requiring minimal agricultural inputs.However,accurately identifying ratoon rice crops is challenging due to the similarity of its spectral features with other rice cropping systems(e.g.,double rice).Moreover,images with a high spatiotemporal resolution are essential since ratoon rice is generally cultivated in fragmented croplands within regions that frequently exhibit cloudy and rainy weather.In this study,taking Qichun County in Hubei Province,China as an example,we developed a new phenology-based ratoon rice vegetation index(PRVI)for the purpose of ratoon rice mapping at a 30 m spatial resolution using a robust time series generated from Harmonized Landsat and Sentinel-2(HLS)images.The PRVI that incorporated the red,near-infrared,and shortwave infrared 1 bands was developed based on the analysis of spectro-phenological separability and feature selection.Based on actual field samples,the performance of the PRVI for ratoon rice mapping was carefully evaluated by comparing it to several vegetation indices,including normalized difference vegetation index(NDVI),enhanced vegetation index(EVI)and land surface water index(LSWI).The results suggested that the PRVI could sufficiently capture the specific characteristics of ratoon rice,leading to a favorable separability between ratoon rice and other land cover types.Furthermore,the PRVI showed the best performance for identifying ratoon rice in the phenological phases characterized by grain filling and harvesting to tillering of the ratoon crop(GHS-TS2),indicating that only several images are required to obtain an accurate ratoon rice map.Finally,the PRVI performed better than NDVI,EVI,LSWI and their combination at the GHS-TS2 stages,with producer's accuracy and user's accuracy of 92.22 and 89.30%,respectively.These results demonstrate that the proposed PRVI based on HLS data can effectively identify ratoon rice in fragmented croplands at crucial phenological stages,which is promising for identifying the earliest timing of ratoon rice planting and can provide a fundamental dataset for crop management activities.

Data Component:An Innovative Framework for Information Value Metrics in the Digital Economy

The increasing dependence on data highlights the need for a detailed understanding of its behavior,encompassing the challenges involved in processing and evaluating it.However,current research lacks a comprehensive structure for measuring the worth of data elements,hindering effective navigation of the changing digital environment.This paper aims to fill this research gap by introducing the innovative concept of“data components.”It proposes a graphtheoretic representation model that presents a clear mathematical definition and demonstrates the superiority of data components over traditional processing methods.Additionally,the paper introduces an information measurement model that provides a way to calculate the information entropy of data components and establish their increased informational value.The paper also assesses the value of information,suggesting a pricing mechanism based on its significance.In conclusion,this paper establishes a robust framework for understanding and quantifying the value of implicit information in data,laying the groundwork for future research and practical applications.

基于Wi-Fi定位技术的建筑使用者动态信息研究

合理的能耗运营管理是建筑节能的有效途径。由于大型公共建筑内部人员动态信息收集难度大,目前大部分建筑节能策略采取约束室内人员行为的方法,其操作程序复杂、节能效率低下。因此,借助Wi-Fi定位技术提出一种精度高、经济性好的室内定位方法,实时收集建筑使用者的实际位置和行动,掌握使用者的基本行动规律,为开展更具科学性的能耗管理与优化奠定基础。

Big Data Access Control Mechanism Based on Two-Layer Permission Decision Structure

Big data resources are characterized by large scale, wide sources, and strong dynamics. Existing access controlmechanisms based on manual policy formulation by security experts suffer from drawbacks such as low policymanagement efficiency and difficulty in accurately describing the access control policy. To overcome theseproblems, this paper proposes a big data access control mechanism based on a two-layer permission decisionstructure. This mechanism extends the attribute-based access control (ABAC) model. Business attributes areintroduced in the ABAC model as business constraints between entities. The proposed mechanism implementsa two-layer permission decision structure composed of the inherent attributes of access control entities and thebusiness attributes, which constitute the general permission decision algorithm based on logical calculation andthe business permission decision algorithm based on a bi-directional long short-term memory (BiLSTM) neuralnetwork, respectively. The general permission decision algorithm is used to implement accurate policy decisions,while the business permission decision algorithm implements fuzzy decisions based on the business constraints.The BiLSTM neural network is used to calculate the similarity of the business attributes to realize intelligent,adaptive, and efficient access control permission decisions. Through the two-layer permission decision structure,the complex and diverse big data access control management requirements can be satisfied by considering thesecurity and availability of resources. Experimental results show that the proposed mechanism is effective andreliable. In summary, it can efficiently support the secure sharing of big data resources.

Redundant Data Detection and Deletion to Meet Privacy Protection Requirements in Blockchain-Based Edge Computing Environment

With the rapid development of information technology,IoT devices play a huge role in physiological health data detection.The exponential growth of medical data requires us to reasonably allocate storage space for cloud servers and edge nodes.The storage capacity of edge nodes close to users is limited.We should store hotspot data in edge nodes as much as possible,so as to ensure response timeliness and access hit rate;However,the current scheme cannot guarantee that every sub-message in a complete data stored by the edge node meets the requirements of hot data;How to complete the detection and deletion of redundant data in edge nodes under the premise of protecting user privacy and data dynamic integrity has become a challenging problem.Our paper proposes a redundant data detection method that meets the privacy protection requirements.By scanning the cipher text,it is determined whether each sub-message of the data in the edge node meets the requirements of the hot data.It has the same effect as zero-knowledge proof,and it will not reveal the privacy of users.In addition,for redundant sub-data that does not meet the requirements of hot data,our paper proposes a redundant data deletion scheme that meets the dynamic integrity of the data.We use Content Extraction Signature(CES)to generate the remaining hot data signature after the redundant data is deleted.The feasibility of the scheme is proved through safety analysis and efficiency analysis.

Traffic Flow Prediction with Heterogeneous Spatiotemporal Data Based on a Hybrid Deep Learning Model Using Attention-Mechanism

A significant obstacle in intelligent transportation systems(ITS)is the capacity to predict traffic flow.Recent advancements in deep neural networks have enabled the development of models to represent traffic flow accurately.However,accurately predicting traffic flow at the individual road level is extremely difficult due to the complex interplay of spatial and temporal factors.This paper proposes a technique for predicting short-term traffic flow data using an architecture that utilizes convolutional bidirectional long short-term memory(Conv-BiLSTM)with attention mechanisms.Prior studies neglected to include data pertaining to factors such as holidays,weather conditions,and vehicle types,which are interconnected and significantly impact the accuracy of forecast outcomes.In addition,this research incorporates recurring monthly periodic pattern data that significantly enhances the accuracy of forecast outcomes.The experimental findings demonstrate a performance improvement of 21.68%when incorporating the vehicle type feature.

Research on Interpolation Method for Missing Electricity Consumption Data

Missing value is one of the main factors that cause dirty data.Without high-quality data,there will be no reliable analysis results and precise decision-making.Therefore,the data warehouse needs to integrate high-quality data consistently.In the power system,the electricity consumption data of some large users cannot be normally collected resulting in missing data,which affects the calculation of power supply and eventually leads to a large error in the daily power line loss rate.For the problem of missing electricity consumption data,this study proposes a group method of data handling(GMDH)based data interpolation method in distribution power networks and applies it in the analysis of actually collected electricity data.First,the dependent and independent variables are defined from the original data,and the upper and lower limits of missing values are determined according to prior knowledge or existing data information.All missing data are randomly interpolated within the upper and lower limits.Then,the GMDH network is established to obtain the optimal complexity model,which is used to predict the missing data to replace the last imputed electricity consumption data.At last,this process is implemented iteratively until the missing values do not change.Under a relatively small noise level(α=0.25),the proposed approach achieves a maximum error of no more than 0.605%.Experimental findings demonstrate the efficacy and feasibility of the proposed approach,which realizes the transformation from incomplete data to complete data.Also,this proposed data interpolation approach provides a strong basis for the electricity theft diagnosis and metering fault analysis of electricity enterprises.

Preserving Data Secrecy and Integrity for Cloud Storage Using Smart Contracts and Cryptographic Primitives

Cloud computing has emerged as a viable alternative to traditional computing infrastructures,offering various benefits.However,the adoption of cloud storage poses significant risks to data secrecy and integrity.This article presents an effective mechanism to preserve the secrecy and integrity of data stored on the public cloud by leveraging blockchain technology,smart contracts,and cryptographic primitives.The proposed approach utilizes a Solidity-based smart contract as an auditor for maintaining and verifying the integrity of outsourced data.To preserve data secrecy,symmetric encryption systems are employed to encrypt user data before outsourcing it.An extensive performance analysis is conducted to illustrate the efficiency of the proposed mechanism.Additionally,a rigorous assessment is conducted to ensure that the developed smart contract is free from vulnerabilities and to measure its associated running costs.The security analysis of the proposed system confirms that our approach can securely maintain the confidentiality and integrity of cloud storage,even in the presence of malicious entities.The proposed mechanism contributes to enhancing data security in cloud computing environments and can be used as a foundation for developing more secure cloud storage systems.