Peking University

Xuanzhe Liu

Gang Huang

Yun Ma

Huaqian Cai

Jing Wang

Yi Liu

Mengwei Xu

Meihua Yu

Yi Ke Wu

Huoran Li

Xuan Lu

Lingxuan Hu

Xiang Jing

Hai'ou Jiang

Xinyang Wang

Hong Mei

A human-cyber-physical resource-oriented adaptive construction method and apparatus for a structured peer-to-peer (P2P) network are provided. The structured P2P network is a point-to-point network with physical perception information and can be effectively used in a human-cyber-physical fusion scenario. The method includes: using a grid aggregation algorithm to calculate the latitude and longitude coordinates of a new node to acquire a position hash value of the new node; determining, according to the position hash value, a registration node of the new node from the existing nodes of the structured P2P network; and completing, according to the information returned by the registration node to the new node, registration of the new node, thereby resulting adding of the registered new node into the structured P2P network.

Human-cyber-physical resource-oriented adaptive construction method and apparatus for structured P2P network

A trusted storage method and system based on a graph structure are provided. The method includes: in a process of initiating a transaction, randomly selecting, by each transaction initiating node, a plurality of witness nodes from a network for witnessing the transaction; packaging, by the witness nodes, transaction data generated by witnessing the transaction to generate blocks; randomly selecting, by the witness nodes, a plurality of storage nodes; sending, by the witness nodes, the blocks to the plurality of storage nodes; and storing, by the storage nodes, the blocks; wherein, for one transaction, all the blocks of all the witness nodes and all the storage nodes form a directed acyclic graph DAG structure. According to embodiments of the disclosure, the directed acyclic graph DAG structure is employed to be matched with an nRW consensus mechanism, so that a supervision problem in a large-scale sharing and exchanging process is solved.

Trusted storage method and system based on directed acyclic graph structure

A self-adaptive execution method for realizing data trustworthiness includes: starting a smart contract, executing the smart contract and verifying an execution result of the smart contract. A random execution mode based on redundant calculation is employed, and multiple nodes in a network are randomly selected to jointly execute a data analysis logic, thereby realizing trusted computing of an execution result in a relatively distrusted environment and improving an execution efficiency of the smart contract. Meanwhile, by recording the execution of the contract in a process of synchronously calling the multiple nodes, a needed execution record of contract calling is acquired from the node in a latest state and replayed locally when synchronization is needed, so that the random multiple nodes can be quickly recovered when states of the random multiple nodes are not synchronized, realizing high availability of data and satisfying a data analysis scenario with low response time.

Self-adaptive execution method of smart contract for realizing data trustworthiness

A data-interoperability-oriented trusted processing method and system applied to a P2P network system are provided. The P2P network system includes a plurality of nodes. The trusted processing method includes a storage method and a query method. Firstly, a directed acyclic graph ledger structure is employed to be matched with an nRW consensus mechanism during a storage process, so that a supervision problem in a large-scale sharing exchange process is solved. Secondly, in a query process, a P2P network system is optimized by maintaining a tree structure with high fault tolerance and load balance through a hop optimization method to construct the P2P network system with a relatively balanced network, so that a query delay is not greatly influenced on the premise of ensuring the load balance, and an expandability of the system is ensured.

Data-interoperability-oriented trusted processing method and system

The present invention relates to a method and system for determining the quality of an application based on user behaviors of application management. The method includes: 1) preprocessing data on user behaviors of application management to obtain a sequence of management behaviors as a training set; 2) extracting features of the user behaviors from the obtained sequence of management behaviors; 3) establishing a multi-dimensional independent variable space using the extracted behavior features, wherein each application in the training set is considered as a point in the space; training a model according to the space; and debugging to obtain optimal model parameters and a definite regression model; 4) arranging the data of the management behaviors of each application to be predicted according to step 1) and step 2), and then inputting the result into the regression model, wherein an output of the regression model is the result of the application quality determination. The present invention can effectively remove irrelevant features and exert the quality expression ability of relevant features, and can obtain more accurate results for evaluation of application quality.

Method and system for determining quality of application based on user behaviors of application management

A permission management method for a trustworthiness mechanism of a big-data blockchain includes: dividing system resources into user-role resources, data resources and node resources; acquiring a current role of a user based on a RBAC module in a R-TBAC model, and acquiring an operating-permission-value range of the current role; monitoring an operating behavior of the user in an operating system, and, based on the RBAC module and according to the operating-permission-value range of the current role, detecting whether the current role of the user has a role-operating permission for the operation; detecting a task-operating permission of the contract instance or task instance based on a TBAC module in the R-TBAC model during running of the contract instance or task instance; and completing, by the user, the operation in an authorized operating permission range based on the R-TBAC model.

Permission management method and system for trustworthiness mechanism of big-data blockchain

The invention discloses a resource optimization method for a mobile browser based on cloud-client cooperation. The present method includes: 1) set up a proxy server on the user's mobile terminal, set up a cloud server on the user's personal cloud; 2) mobile terminal proxy server receives and resolves the URL request from the browser, and if the mobile terminal proxy server resources have been cached URL corresponding to the request, or calculated by the URL matching algorithm there is a corresponding resource, the process directly returns the resource to the browser; otherwise, it sends the request to the cloud server; 3) the cloud server checks if the resource corresponding to the URL in the request has been cached; if the resource is cached, returning the resource to the proxy server; otherwise sending a request to the target website corresponding to URL in the resource request and returning the results to the proxy server; and 4) returning the result received by the proxy server to the browser in accordance with the structure of the HTTP response. The invention greatly improves the loading speed.

Method for optimizing resource loading at mobile browsers based on cloud-client cooperation

The present application discloses a method for assembling ANDROID application based on application content. The method includes: 1) a server captures page information of an ANDROID application and creates an index, and saves metadata and index information of the page to a database, wherein the metadata includes the page jump logic of the ANDROID application; 2) a client sends a keyword input by a user to the server; 3) the server obtains an application list matching the keyword from the database and returns the metadata corresponding to the application list to the client; 4) after a target ANDROID application is selected from the application list, the client launches the target ANDROID application and automatically jumps to the page corresponding to the keyword according to the page jumping logic of the target ANDROID application. The invention breaks the isolation of information and provides a more natural assembly service among ANDROID applications.

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Beijing, China

Xuanzhe Liu