Big Data and Security: Second International Conference, ICBDS 2020, Singapore, Singapore, December 20–22, 2020, Revised Selected Papers (Communications in Computer and Information Science, 1415)

This book constitutes the refereed proceedings of the Second International Conference on Big Data and Security, ICBDS 2020, held in Singapore, Singapore, in December 2020. The 44 revised full papers and 8 short papers were carefully reviewed and selected out of 153 submissions. The papers included in this book are orfanized according to the topical sections on cybersecurity and privacy, big data, blockchain and internet of things, and artificial intelligence/ machine learning security. Preface Organization Contents Cybersecurity and Privacy Application and Research of Power Communication Trusted Access Gateway 1 Introduction 2 Research on Access Authentication 2.1 Access Authentication Method for Power Communication Network 2.2 Certification Framework for Power Communication Networks 3 Design of Trusted Access Gateway for Power IoT 4 Development and Test of Power Trusted Access Gateway 4.1 Development of Trusted Access Gateway 4.2 Test Analysis of Service Access Gateway 5 Conclusion References The Database Fine-Grained Access SQL Statement Control Model Based on the Dynamic Query Modification Algorithm 1 Introduction 2 Related Work and Background 2.1 Related Research 2.2 FGAC Strategy 3 Dynamic Query Modification Algorithm Based on Key Attributes 4 Algorithm Performance Evaluation 4.1 Robustness Definition 4.2 Robustness of Relational Algebra Expression 4.3 Robustness of KAB Algorithm 5 Experiment 5.1 Experiment Environment 5.2 Experiment Results and Analysis 6 Conclusion References Research on Application Technology and Security of VoLTE in Power Wireless Private Network 1 Introduction 2 System Architecture of VoLTE 3 Analysis of User Requirements in Power Network 4 Test Environment of VoLTE 5 Test Result 5.1 Test of Voice Quality 6 Test of Video Quality 7 Road Test 8 Conclusion References Semi-supervised Time Series Anomaly Detection Model Based on LSTM Autoencoder 1 Introduction 2 Related Work 3 Proposed Anomaly Detection Scheme 3.1 Symbols and Problem Statement 3.2 Our Model 3.3 Unsupervised LSTM Autoencoder 3.4 Semi-supervised LSTM Autoencoder 4 Experiments 4.1 Datasets 4.2 Baseline Methods 4.3 Evaluation Metrics 4.4 Result and Analysis 5 Conclusion and Future Work References Fault Inspection of Brake Shoe Wear for TEDS Based on Machine Vision 1 Introduction 2 Fast Positioning of Brake Shoe 3 Judgment on the Wear of Brake Watt 3.1 Linear Segmentation of Image Edges 4 Conclusion References Android Malware Detection Method Based on App-Image Conversion 1 Introduction 2 Related Work 2.1 Android Malware and Detection 2.2 Grayscale Image and Android Malware 2.3 Convolutional Neural Networks 3 Malware Detection Based on App-Image Conversion 3.1 Malware Detection Framework 3.2 Grayscale Image Conversion 4 Experiments 4.1 Environment and Data Set 4.2 Parameters of CNN 5 Conclusion References Research on IMS Security Access and Mechanism in Power System 1 Introduction 2 IMS Meeting Operational Platform 3 Current Status of Authentication Algorithm in IMS Network 4 An Authentication Algorithm for Converting Unkey Encryption Technology and ECC 4.1 Security Gaps in IMSAKA Mechanisms 4.2 Specific Flow of Improved Algorithms 5 Simulation and Analysis of Algorithm 5.1 Analysis of Security 5.2 Performance Analysis 6 Conclusion References Research on the Role-Based Access Control Model and Data Security Method 1 Introductions 2 Related Overview 2.1 Access Control 2.2 RBAC Model of the System 3 RBAC Model Design 3.1 Layered System Framework 3.2 Database Design 4 Method Design 4.1 Identity Verification 4.2 Verification Code 4.3 AC Interface 4.4 Prevent Illegal Users from Logging in to the System 4.5 Database Security: Oracle Parameters 4.6 Database Security: Stored Procedures 5 Conclusion References Research on Network Optimization and Network Security in Power Wireless Private Network 1 Introduction 2 Analysis of Service Requirements 3 Link Budget 4 Coverage Simulation 4.1 Dense Urban Areas 4.2 Urban Areas 4.3 Suburban and Rural Areas 5 Capacity Planning 6 Conclusion References Research on Location Planning of Multi-station Integration Based on Particle Swarm Optimization 1 Introduction 2 Mathematical Model of Multi-station Location 2.1 Multi-station Integration Architecture 2.2 Mathematical Model of Location 3 Solution of Multi-station Location Model 3.1 Particle Swarm Optimization (PSO) 3.2 Solution Process of Location Model Based on PSO 4 Case Study 4.1 Basic Parameters 4.2 Case Results and Analysis 5 Conclusion References Quick Response Code Based on Least Significant Bit 1 Introduction 2 Test Results 3 Conclusion References Event-Based H Control for Networked Control System with Saturation Constraints 1 Introduction 2 System Description 3 Main Results 4 Illustrative Examples 5 Conclusion References Privacy Preserving Data Sharing in Online Social Networks 1 Introduction 1.1 Motivational Scenario 2 Preliminaries 3 Related Work 4 The System Model and LDP Algorithm 5 Experimental Setup 6 Conclusion References Indoor and Outdoor Fusion Positioning and Security Technology Based on Beidou Satellite 1 Introduction 2 Positioning Technology Based on Signal Strength of WiFi 2.1 Propagation Model of WiFi Indoor Signal 2.2 WiFi Indoor Positioning System 2.3 Fusion Positioning System Based on Beidou and Indoor WiFi 3 WiFi Fingerprint Matching Algorithm 4 Simulation Experiment of Indoor Positioning Based on Weighted Signal Space kWNN Algorithm 5 Conclusion References Research on Safety Protection Scheme of Distribution Network Automation 1 Introduction 2 Design of Safety Protection Schemes 3 Data Classification Processing Based on Random Forests 3.1 Data Collection and Disaggregation of Data Sets 3.2 Data Preprocessing 3.3 Optimization of Random Forest Model 3.4 Classification Results and Model Evaluation 4 Symmetric Encryption Based on Neural Network 4.1 Mathematical Modeling Based on Neural Networks 4.2 Symmetric Encryption Algorithm Based on Neural Network 4.3 Design of Secure Encryption Device Based on Symmetric Encryption Algorithm 5 Conclusion References Research on Experimental Verification Scheme of 5G in Power System 1 Introduction 2 Selection of Validation Environment 2.1 Laboratory Validation 2.2 Field Validation 3 Application of Network Slice Technology in Power System 3.1 Characteristics of Power Service 3.2 Adaptive Model of 5G and Multiple Power Services 3.3 Customized Scheme for Power Network Slicing 4 Validation in the Laboratory Environment 4.1 Environment of Validation 4.2 Content of Validation 4.3 Scheme of Validation 5 5G Verification Scheme in Field Environment 5.1 Verification Environment 5.2 Content of validation 5.3 Scheme of validation 6 Conclusion References Immune Network Based Anomaly Detection Algorithm 1 Introduction 2 Proposed Algorithm 2.1 Basic Definition 2.2 Immune Network 3 Algorithm Detail 3.1 Immune Network Generation Phase 3.2 Mature Detector Training Phase 3.3 Detection Phase 4 Experiment 5 Summary References Incremental Anonymous Privacy-Protecting Data Mining Method Based on Feature Correlation Algorithm 1 Introduction 2 Related Work 3 Problem Definition 3.1 Anonymous Stream Data on Sliding Window 3.2 Correlation Feature and Sensitivity Matrix on the Basis of Background Knowledge 3.3 Overview of Feature Correlation Algorithm 3.4 Anonymization 4 RSLK Anonymous Algorithm 5 Experiment Result 5.1 Effective Time 5.2 Running Time 6 Conclusion References The Privacy Data Protection Model Based on Random Projection Technology 1 Introduction 2 Random Projection Technology 3 Personal Privacy Data Protection Model 3.1 Secure Subspace Method 3.2 Random Orthogonal Transformation 4 Multiplicative Perturbation Technique Based on Random Projection 4.1 ICA Model 4.2 Decomposability 4.3 Multiplicative Disturbance Based on Random Projection 5 Results and Analysis 5.1 The Influence of Safety Subspace on Inner Product and Euclidean Distance 5.2 Multiplicative Disturbance Analysis Based on Random Projection 6 Conclusion References Event-Driven H Control for Networked Control Systems with Random Actuator Nonlinearity 1 Introduction 2 System Description 3 H Control Performance Analysis 4 H Controller Design 5 Illustrative Examples 6 Conclusion References Research on the Sensitive Data Protection Method Based on Game Theory Algorithm 1 Introduction 2 Big Data Privacy Protection Method for User Location Information 2.1 System Model 2.2 User Location Big Data Privacy Protection Algorithm Based on Game Theory 2.3 Algorithm Description 3 Simulation and Result Analysis 4 Conclusion References Research on Differential Protection and Security in Power System Under 5G Environment 1 Introduction 2 Research on Multi-access EdgeCompute 2.1 Architecture Design of MEC Platform 2.2 Diversion Mechanism of Low Delay Service 2.3 Research on Channel Model 3 Application of Network Slice Technology in Power System 3.1 Characteristics of Power Service 3.2 Adaptive Model of 5G and Multiple Power Services 3.3 Customized Scheme for Power Network Slicing 4 Application of Differential Protection Based on 5G 4.1 Characteristics of Differential Protection Services 4.2 Application of Differential Protection Service 5 Conclusion References Research on Intelligent Fault and Security Handling Based on IMS in Power System 1 Introduction 2 Theoretical Research on Intelligent Fault Handling in IMS 3 Integrated Operation and Maintenance Platform for IMS 3.1 The Overall Architecture of the IMS Platform 3.2 Deployment Architecture of IMS Platform 3.3 Function Design of Intelligent Fault Handling 4 Realization of Intelligent Fault Handling 4.1 The Process of Fault Handling 4.2 Process of Fault Analysis for Core Network 4.3 Monitoring Process of IAD 4.4 Process to Secure Key Users 4.5 Display of Intelligent Fault Handling in IMS 5 Conclusion References Research on System Simulation and Data Analysis of Power Wireless Private Network 1 Introduction 2 Analysis of User Requirements in Power Network 3 Introduction of Simulation System 3.1 Parameter Configuration of the System 4 Link-Level Simulation 4.1 Topological Structure of the System 4.2 Simulation of Channel Environment 5 System-Level Simulation 6 Conclusion References Research on Attitude Control System of Four-Rotor Aircraft 1 Introduction 2 Dynamic Model of the Four-Rotor Aircraft 3 Algorithm Design Based on PSO-RBF 3.1 RBF Neural Network 3.2 Particle Swarm Algorithm 3.3 Improved PSO Algorithm 3.4 PSO-RBF Algorithm Design 4 Construction and Simulation of the Control System of the Four-Rotor Aircraft 4.1 Construction Based on PSO-RBF Controller 4.2 Simulation and Result Analysis 5 Conclusion References Big Data A Method for Image Big Data Utilization: Automated Progress Monitoring Based on Image Data for Large Construction Site 1 Introduction 2 Research Status and Progress 2.1 Progress Recognition Method Based on Image 2.2 The Work of This Paper 3 Automated Monitoring Method of Individual Building Progress in Large-Scale Level Construction Site 3.1 Design Information Extraction 3.2 3D Reconstruction of Construction Site Scene 3.3 The Extraction of the Point Cloud and Progress Identification 4 Case Study and Method Validation 4.1 Site Scale and Building Positioning 4.2 Image Acquisition 4.3 3D Reconstruction and Point Cloud Generation 4.4 Extract the Construction Floor Number of Each Batch 5 Conclusion and Prospect References Big Data from Collection to Use in Competitive Games—A Study Case on Badminton 1 Introduction 2 Data Collection from Badminton Match 2.1 1st Order Data – Only Considering the Real Hit Path 2.2 2nd Order Data – Considering the Predict Path and Real Path 2.3 Two Dimensions Data – Giving the High Weight of Key Hits 2.4 Higher Orders Data – Considering More Steps 2.5 Higher Dimensions Data – Considering the Specific Situations 3 Data Analysis 3.1 Analysis of Hits at a Specific Point 3.2 Analysis of Tactics that Leads to Initiative Situation 3.3 Analysis of Decisions that Results in Passive Situation 4 Applications 4.1 Training 4.2 Identification of Opponent’s Routine Tactics 4.3 Identification of Opponent’s Tricks 4.4 Improvement of Drawbacks 4.5 Capacity Test 4.6 Selection of Players for the Next Competition 5 Difficulties and Solutions for the Further Study 5.1 Accurate Appraisal by Professionals 5.2 Fast Updating and Computing 5.3 More Realistic Simulation 6 Conclusions References The Interactive Query Method with Clustering and Differential Privacy Protection Model Under Big Data Environment 1 Introduction 2 Relevant Work and Background 2.1 Relevant Research 2.2 Differential Privacy Protection Background 2.3 Distance and Centroid Calculation of Mixed Data 3 Research on Big Data Interactive Query Model with Differential Privacy Data 3.1 Distance and Centroid Calculation of Mixed Data 3.2 Improved Clustering Query Method to Maintain Differential Privacy 3.3 Interactive Query of Big Data 4 Experiment 4.1 Experimental Data 4.2 Experimental Results and Analysis 5 Conclusion References Research on Spatio-Temporal Characteristics of Distribution Network Voltage Based on Big Data 1 Introduction 2 Data Processing for the Evaluation of Temporal and Spatial Characteristics 2.1 Static Data Processing 2.2 Dynamic Data Processing 3 Analysis of Distribution Network Voltage Spatial Characteristics 3.1 User Voltage Qualification Rate 3.2 Comprehensive Voltage Qualification Rate of Distribution Transformer 3.3 Feeder Comprehensive Voltage Qualification Rate 3.4 Comprehensive Voltage Qualification Rate of Substation 4 Analysis of Voltage-Time Characteristics of Distribution Network 4.1 Calculation of Voltage Failure Rate by Time Period 4.2 Improvement of K-means Clustering Algorithm 4.3 Recognition of Interval Voltage Unqualified Based on Improved K-means Clustering Algorithm 5 Case Analysis 5.1 Comparison of K-means Clustering Algorithm Before and After Improvement 6 Analysis of Distribution Network Voltage Spatial Characteristics 6.1 Recognition of Voltage Period Characteristics of Distribution Network References Oracle Data Privacy Protection System of Virtual Database 1 Introduction 2 Oracle Database Architecture 3 Data Privacy Protection Rules 3.1 Probabilistic Causal Network Model 3.2 Similar Attributes Identification 3.3 Calculation of Probability Effects 4 Data Privacy Protection System 4.1 Narrowing the Range 4.2 Blocking 4.3 Aggregation 4.4 Restoration 4.5 Security Policy 5 System Evaluation 5.1 Database Collection and System Evaluation 5.2 Effectiveness Assessment 6 Conclusion References Enterprise Credit Decisions Using Logistic Regression and Particle Swarm Optimization Based on Massive Data Records 1 Introduction 2 Logistic Regression Algorithm 2.1 Mapping 2.2 Transformed into a Logarithmic Likelihood Function 2.3 Optimization Problem Solving 3 The Processing Method of This Paper 3.1 Selection of Evaluation Indexes 3.2 Quantitative Calculation of Evaluation Indexes 3.3 Construction of Evaluation Index System 3.4 Establishment of Evaluation Model Based on Logistic Regression Algorithm 3.5 Particle Swarm Optimization Algorithm for Optimal Numerical Solution 4 Experimental Results 4.1 Establishing Default Rate Model by Logistic Regression 4.2 Particle Swarm Optimization 5 Conclusion References A Novel Artificial Immune Model on Hadoop for Anomaly Detection 1 Introduction 2 A Novel Artificial Immune Model on Hadoop for Anomaly Detection 2.1 The Candidate Detector Generation Phase 2.2 Mature Detector Dynamical Evolution 2.3 The Detection Phase 3 Experiment 4 Summary References Research on Accurate Location of Line Loss Anomaly in Substation Area Based on Data Driven 1 Introduction 2 The Architecture of Precise Positioning of Abnormal Line Loss Associated User 3 Line Loss Exception Library Generating Based on the Improved Dichotomous K-means++ Clustering 3.1 Improved Dichotomous K-means++ Clustering a Subsection Sample 3.2 Selection of Clustering Number Based on GSA Algorithm 3.3 Generation of Line Loss Exception Library 4 Joint Research and Judgment Based on Multi-indicator Parameters 4.1 Szpilman Correlation Coefficient (SCC) 4.2 Discrete Fraser Distance (DFD) 4.3 Construction of Joint Judgment Indexes 5 Example Simulation and Analysis 5.1 Case Background Introduction 5.2 Analysis of Example Results 6 Conclusion References A Reactive Power Reserve Prediction Method for EV Charging Piles Based on Big Data and Optimized Neural Network 1 Introduction 2 EV Charging Pile Dynamic Reactive Power Reserve 2.1 Reactive Power Source of Electric Vehicle Charging Pile 2.2 The Definition of Reactive Power Reserve 2.3 Basic Model of Reactive Power Reserve of Charging Piles for Electric Vehicles 3 Particle Swarm Algorithm 3.1 Basic Concepts of Particle Swarm Optimization 3.2 The Basic Model of Particle Swarm Optimization 4 BP Neural Network Algorithm 4.1 Basic Concept of BP Neural Network 4.2 Basic Model of BP Neural Network 5 Flexible Load Reactive Power Reserve Prediction Based on Big Data Analysis 5.1 Data Processing 5.2 Specific Steps 5.3 Parameter Settings 6 The Example Analysis 6.1 Neural Network Training 6.2 Example Results 6.3 Analysis of Example Results 7 Conclusion References Research on Scattered Point Cloud Coordinate Reduction and Hole Repair Technology Based on Big Data Model 1 Introduction 2 Reduction and Denoising of Scattered Point Clouds 2.1 The Establishment of Ball Mould 2.2 Coding Sequence of Vertebral Region 2.3 Fast Reduction Denoising Algorithm Based on Sphere Module 3 Hole Repair of Scattered Point Cloud 3.1 Radial Basis Function Model 3.2 Algorithm Flow 4 Experiment and Analysis 5 Summary References Survey on Computation Offloading Schemes in Resource-Constrained Mobile Edge Computing 1 Introduction 2 Introduction to Computation Offloading in MEC 2.1 Computation Offloading Concept and Process 2.2 Computation Offloading Policy 2.3 Computation Offloading Goals 3 MEC Computation Offloading Schemes 3.1 Single-Server Computing Scenario 3.2 Collaborative Computing Scenario 3.3 Summary 4 Open Challenges 5 Conclusion References Blockchain and Internet of Things Discussion on the Influence of 5G and Blockchain Technology on Digital Virtual Assets 1 Introduction 2 Blockchain Technology 2.1 The Concept of Blockchain Technology 2.2 Characteristics of Blockchain Technology 2.3 Smart Contract Based on Blockchain Technology 3 Cross Fusion of 5G Network and Blockchain Technology 3.1 The Role of Blockchain Technology in Promoting 5G Network 3.2 The Role of 5G Network in Promoting Blockchain Technology 4 Digital Virtual Assets 4.1 The Development of Digital Virtual Asset Protection 4.2 Characteristics of Digital Virtual Assets 5 The Effect of 5G+ Blockchain on Digital Virtual Assets 5.1 5G+ Blockchain Endows Digital Virtual Assets with New Features 5.2 Application of 5G+ Blockchain in Confirmation of Digital Copyright 5.3 Application of 5G+ Blockchain Technology in the Secure Transaction of Digital Virtual Assets 6 Concluding Remarks References Research on Power Universal Service Access Gateway Based on Blockchain 1 Introduction 2 Distributed Authentication Based on Block Chain 2.1 Features of Power Communication Networks 2.2 Model and Process of Distributed Authentication 3 Design of Service Access Gateway for Electric Communication Network 3.1 Hardware of Gateway System 3.2 Software of Gateway System 4 Testing and Analysis of Gateway 4.1 Scenario for Testing 4.2 System Topology for Gateway Deployment 4.3 Terminal Testing Under Wired Communication 5 Conclusion References Application of Whole-Service Ubiquitous Internet of Things in Power System 1 Introduction 2 Architecture of the Internet of Things 2.1 Overall Structure 2.2 Technical Framework 3 Key Technology 3.1 Multiple Types of Terminal Communications 3.2 Communication Technology of LTE Wireless Communication Private Network 3.3 Real-Time Video Conference Technology Based on Internet of Things 3.4 Characteristics of Power Service 3.5 Customized Scheme for Power Network Slicing 4 Typical Service Scenarios 4.1 Electrical Information Collection 4.2 Wisdom Inspection 4.3 Emergency Protection 4.4 Intelligent Warehousing 4.5 Integrated Monitoring of Ring Cabinets 4.6 Distributed Photovoltaic Monitoring 5 Conclusion References Artificial Intelligence/Machine Learning Security Learning Depth from Light Field via Deep Convolutional Neural Network 1 Introduction 2 Related Work 3 Methodology 3.1 Geometric Pattern of Depth Information 3.2 Network General Framework 3.3 Multi-stream Architecture 3.4 Skip Connection 4 Experimental Results 4.1 Experimental Setup 4.2 Evaluation Metrics 4.3 Comparison to State-of-the-Art 5 Conclusions References Cycle-Derain: Enhanced CycleGAN for Single Image Deraining 1 Introduction 2 Related Work 2.1 GAN and CycleGAN 2.2 Single Image Deraining (SID) 3 Problem Model 3.1 Network Architecture 3.2 Attention Mechanism 4 Experiments and Results 4.1 Baselines 4.2 Datasets 4.3 Network Architecture 4.4 Training Details 4.5 Experimental Results 5 Conclusion References Sensitive Data Recognition and Filtering Model of Webpage Content Based on Decision Tree Algorithm 1 Introduction 2 Related Work 3 Recognition and Filtering Method of Sensitive Data Based on Decision Tree 3.1 Privacy Protection 3.2 Data Mining 3.3 Privacy Level and Mining Quality 4 Experiment 4.1 Experiment Result 4.2 Experiment Analysis 5 Conclusion References Hard Disk Failure Prediction via Transfer Learning 1 Introduction 2 Related Work 3 Proposed Approach 3.1 Data Processing 3.2 Construction of 2D-SMART Attributes 3.3 Transfer Learning Component 4 Experimental Results 4.1 Dataset 4.2 Evaluation Metric 4.3 Results 5 Conclusion References Design and Application of CMAC Neural Network Based on Software Hardening Technology 1 Introduction 2 Working Principle of CMAC Neural Network 2.1 CMAC Network Structure 2.2 Concept Mapping Algorithm 2.3 Physical Mapping Algorithm 2.4 Learning Algorithm of CMAC 3 CMAC Neural Network Hardening Method 4 Realization of CMAC Neural Network Motor Control System 5 Conclusion References Research on Path Planning of Mobile Robot Based on Deep Reinforcement Learning 1 Introduction 2 Preliminaries 3 A Path Planning Method Based on the HDQN Algorithm 3.1 The Structure Framework of the HDQN Algorithm 3.2 Definition of Reward Function 3.3 The Heuristic Knowledge Pool 4 Simulation and Analysis of Path Planning for Mobile Robot 4.1 Simulation Experiment Environment 4.2 Comparison of Algorithms 5 Conclusions References Research on K-Means Clustering Algorithm Based on Improved Genetic Algorithm 1 Introduction 2 Research Status of Data Mining 3 The Common Data Mining Technologies Are as Follows 4 Cluster Analysis 4.1 Classification of Clustering Algorithms and Their Typical Algorithms 5 Improved Genetic Optimization K-Means Clustering Algorithm 6 Algorithm Test and Result Analysis References Research on Low Voltage Early Warning of Distribution Network Based on Improved DNN-LSTM Algorithm 1 Introduction 2 Low Voltage Warning in the Platform Area 3 Based on Equivalent Load-Voltage Sensitivity 3.1 Single Load-Voltage Sensitivity 3.2 Load-Voltage Sensitivity Based on Equivalent Load and Line in the Platform Area 4 Load-Voltage Sensitivity Based on Big Data Analysis 4.1 Comprehensive Voltage Deviation of Platform Area 4.2 DNN-LSTM Model Based on EMD 5 Case Analysis 6 Conclusion References Cross-Task and Cross-Model Active Learning with Meta Features 1 Introduction 2 Related Work 2.1 Active Learning (AL) 2.2 Meta Learning 3 Problem Setting 3.1 Active Learning (AL) 3.2 Meta Learning 4 Method 4.1 Meta Feature 4.2 Generation of Meta Data 5 Experiments 5.1 Datasets 5.2 Meta Regressor 5.3 Baselines 5.4 Results 6 Conclusion References Improved Random Forest Algorithm Based on Attribute Comprehensive Weighting Used in Identification of Missing Data in Power Grid 1 Introduction 2 Random Forest Theory 2.1 CART Regression Decision Tree 2.2 Bagging Algorithm Based on Bootstrap Sampling 2.3 Random Forest Algorithm 3 Attribute Comprehensive Weighting Strategy Based on Correlation Analysis 3.1 Correlation Analysis Based on Pearson Coefficient 3.2 Attribute Comprehensive Weighting Strategy Based on Error Expectation 4 Improved Random Forest Algorithm Based on Attribute Comprehensive Weighting 5 Case Analysis 5.1 Error Analysis Standard 5.2 Analysis of Filling Results 6 Conclusion References Course Classification of Online Learning Platform Based on Sentence-Bert Model 1 Introduction 2 The Sentence-BERT Model 2.1 Sentence Vector Generation Strategy 2.2 Model Objective Function 2.3 Pre-training and Fine-Tuning of the Model 3 Method of Generating Sentence Embedding Based on SBERT 4 The Experimental Results and Analysis 4.1 K-means Text Clustering Experiment Results and Analysis 4.2 Sentence-BERT Semantic Search Experimental Results and Analysis 5 Conclusion References Analysis of Economic Loss of Voltage Sag Based on Artificial Intelligence Algorithm 1 Introduction 2 DBN-DNN 3 Voltage Sag Economic Loss Characteristic Factor 3.1 Severity of Voltage Sag 3.2 Sensitive Equipment Load Voltage Tolerance Curve 3.3 Process Parameter Immunity Time 3.4 Load Failure Probability Distribution 3.5 Input Eigenvector of Economic Loss from Voltage Sag 4 Economic Loss Forecast Model for Voltage Sag 4.1 Modeling Process 4.2 Small Sample Data Enhancement 4.3 Training and Test Data Set Division 4.4 Eigenvector to Dimensional Normalization 5 Calculation Examples and Result Analysis 5.1 Introduction to Calculation Examples 5.2 DBN-DNN Model Training and Prediction 5.3 Samples Enhance Evaluation Performance 5.4 Performance Evaluation of 4 Different Network Architectures 6 Conclusion References Posterior Transfer Learning with Active Sampling 1 Introduction 2 Related Work 3 The Proposed Approach 3.1 Notations 3.2 Preparations 3.3 Transfer Learning with Posterior Probability 3.4 Active Learning with Posterior Probability 4 Experiments 4.1 Data Sets and Settings 4.2 Experiments on Transfer Learning 4.3 Experiments Combing Transfer and Active Learning 5 Conclusion References Author Index This book constitutes the refereed proceedings of the Second International Conference on Big Data and Security, ICBDS 2020, held in Singapore, Singapore, in December 2020.The 44 revised full papers and 8 short papers were carefully reviewed and selected out of 153 submissions. The papers included in this book are organized according to the topical sections on cybersecurity and privacy, big data, blockchain and internet of things, and artificial intelligence/ machine learning security.