634results about How to "Reduce storage overhead" patented technology

Disclosed is a multi-dimensional selectivity estimation method using compressed histogram information which the database query optimizer in a database management system uses to find the most efficient execution plan among all possible plans. The method includes the several steps to generate a large number of small-sized multi-dimensional histogram buckets, sampling DCT coefficients which have high values with high probability, compressing information from the multi-dimensional histogram buckets using a multi-dimensional discrete cosine transform(DCT) and storing compressed information, and estimating the query selectivity by using compressed and stored histogram information as the statistics.

The invention discloses an ATM security certificate and a pre-warning method based on face recognition. The invention introduces face recognition and video detection into the applications of ATM and bank card business for the first time, which can obviously improve the security of ATM financial system, effectively reduce and overawe various ATM fraud and criminal activities. The complete system operation process in the method of the invention is: firstly, registering the face information of a holder at a service window which arranges an infrared face acquisition equipment or with the registration by the users themselves on ATM in bank, and saving the encrypted face information to a bank database and a bank card. Then, determining whether the ATM operator to be recognized is the holder of the bank card or not through verifying the user's identity by a face recognition engine; determining and recognizing whether existing behaviors that threaten ATM and the users though a behavior monitoring engine; and determining whether to trigger corresponding pre-warning mechanism or not according to the recognition result. The invention can extend to the applications of bank book business, public security monitoring and pursuing escaped criminals, etc.

The invention discloses the technical field of wireless communication and wireless network positioning, and in particular relates to an improved positioning method of an indoor fingerprint based on a clustering neural network. According to the technical scheme, the positioning method is characterized by comprising the following steps of: an offline phase: constructing a fingerprint database by fingerprint information collected from a reference point, sorting fingerprints in the fingerprint database by utilizing a clustering algorithm, and training the fingerprint and position information of each reference point by utilizing a artificial neural network model to obtain an optimized network model; and an online phase: carrying out cluster matching on the collected real-time fingerprint information and a cluster center in the fingerprint database to determine a primary positioning area, and taking the real-time fingerprint information in the primary positioning area as an input end of the neural network model of the reference point to acquire final accurate position estimation. The method has the advantages that low calculation and storage cost for the clustering artificial neural network fingerprint positioning method can be guaranteed, the positioning accuracy of the clustering artificial neural network fingerprint positioning method can be improved, and accurate positioning information is provided for users.

The invention discloses a user-oriented cloud storage data integrity protection method. The method includes the steps of 1, uploading, wherein a user side segments and numbers a file to generate intra-block redundancy check codes, the hash value of each file block is calculated and saved as a range-based 2-3 tree, the hash values are linked into one value and signed with private keys, and inter-block redundancy check codes are generated and encrypted with stream substitution secret keys; 2, verification, wherein a cloud management node sends a verification request to a corresponding cloud storage server, corresponding original data and algebraic signatures of the inter-block redundancy check codes corresponding to the original data are calculated and returned to the user side for data integrity verification, and the step 3 is executed if data destruction is found; 3, recovery, wherein the user side acquires all the file blocks on corresponding branch trees from a cloud side according to tree information and performs error recovery on the file blocks through erasure codes of the file blocks. According to the method, integrity verification and recovery are performed on the dynamic data stored in the cloud side from the user perspective.

The invention discloses a route exchange method suitable for a GEO/LEO double layered constellation network. According to the method, a system period is divided into equal-duration time sections based on a dynamic boundary value; a GEO layer satellite high in on-board processing capacity is used for calculating the best route and the second best route for each LEO satellite; in the processes of information transmission and exchange, when loads of the LED satellites are large, the GEO satellite shares part of low priority services in time for the LED satellites, and it is guaranteed that important information is reliably transmitted in real time; when link congestion, node ineffectiveness and other emergency conditions happen in the satellite network, in order to avoid rerouting of the whole network, and the GEO satellite only calculates rerouting for affected routes; after link congestion is eliminated, the LED satellites recover route information in time before congestion in order to avoid link resource waste in the network. In the network that topology time varying happens, links are prone to congestion, on-board resources are limited, continuous high-load flows are prone to being generated, and nodes are prone to being ineffective at the special period, the method can reduce constellation system cost, shorten convergence time, save the on-board resources, increase the utilization rate of the link resources, guarantee that important information is reliably transmitted in real time and improve invulnerability and robustness of the satellite network.

The invention discloses a cluster fault tolerance system, a device and a method. The system includes: a remote checkpoint server which is used to respond the remote checkpoint request from a faulty node and execute the checkpoint operation; a node faulty checking module which is used to monitor the operating system of a local node and the running state of an assigned process and to trigger a remote checkpoint; and a communication system checkpoint module which is used to realize the checkpoint of the communication device and support the recovery function of communication breakpoint. The invention provides localized fast fault restoration for the parallel processing cluster, has a lower overhead and good expansibility, and makes ideal availability for the cluster system with ten billions and hundred billions calculation scale.

The invention discloses an efficient verifiable multi-keyword sequencing searchable encryption method supporting a preference search and a logic search. The encryption method comprises the following steps that a data owner encrypts a document, constructs a cryptogram index based on a document collection, generates summary information of the document by utilizing a secret key and the content of thedocument, and then sends a cryptogram document, an encrypted index and the summary information to a cloud server; a data user shares the information of the secret key, which is generated by the dataowner, generates a query trap door according to a query, and sends an encrypted query trap door and the number K of to-be-obtained documents to the cloud server; the cloud server can execute safe inner product operation after receiving the cryptogram index and the query trap door, searches for K documents most relevant to the query of the user, sequences according to relevant values among the K documents and the query, then generates verification objects, and finally returns the most relevant K documents and the verification objects to the data user, and the data user verifies the correctnessand completeness of a return result through a verification algorithm.

The invention discloses a method and device for client side and server side data synchronization and belongs to the field of database technologies. The method includes the steps that total data of a data object of a server side at a first moment are obtained; according to version numbers of data records, incremental data, changing relative to the first moment, of the data object of the server side at a second moment are obtained, wherein the second moment is later than the first moment; the total data and the incremental data are merged, so that total data of the data object at the second moment are obtained. According to the method and device, the number of times of interaction and the data size of interaction transmission between the client side and the server side can be reduced, and storage consumption of the client side can be reduced.

The invention provides a real-time multi-view network hotspot event analyzing device and an analyzing method thereof. The analyzing device comprises a network event data collecting device, a network event data preprocessing device, an event central processing device and an output device. The analyzing method comprises a network event information collecting step, a network event spotting step, a network event central initializing step, a network event similarity comparing step, a network event multi-center generating step and a hotspot event outputting step. With the device and the method thereof adopted, hotspot event information currently published on the internet can be real-timely spotted and the developing process of the event can be shown in multi-views to help network management personnel to know the trend of network hotpot events more comprehensively.

A computer readable storage medium includes executable instructions to store load data in new rows of an append only table within a data warehouse, without updating or deleting existing rows in the append only table. The new rows are added in a database transaction that guarantees that the distributed reads and writes of all transactions are processed reliably and that the transactions obey snapshot isolation rules. Data changes associated with the load data are maintained in a separate update table. Data from the append only table is merged with data changes from the update table to supply read data.

The embodiment of the invention discloses a method used for processing a polarization code and a communication device. The method comprises the steps of obtaining a first serial number set of M uncoded bits corresponding to the number M of target coded bits based on preset first mapping relationship information and the number M of the target coded bits, wherein the first mapping relationship information is used for indicating a one-to-one correspondence relationship between the number of the multiple coded bits and the serial number set of the multiple uncoded bits, the M uncoded bits comprise K information bits, and the M target coded bits are obtained after the M uncoded bits are subjected to polarization coding; and selecting K serial numbers from the first serial number set of the M uncoded bits according to a preset first selecting rule to serve as a serial number set of the K information bits. In the embodiment, the corresponding relationship between the length 2n of the coded bits and the serial number set of the uncoded bits can only be included, so the storage space is greatly reduced, and the coding and decoding efficiency of the polarization code is improved.

The invention relates to an optimizing method for storing virtual machine mirror images based on CAS (content addressable storage). The method specifically comprises the following steps of adopting a CAS method to divide a virtual machine mirror image file into blocks, calculating fingerprint sequences, and judging the repetitive data through the fingerprint sequences. Only one data block is reserved for the data blocks with the same content, and the number of corresponding share times is stored in each block file. The original file is actually stored with the finger sequences (as shown in Figure 3), and the data part is stored in a shared storage system. To ensure the transparent storage of a virtual machine monitor and the portability of the shared storage system, the operation process of the virtual machine mirror images is packaged into the realizing process of a corresponding system calling and response interface by a FUSE (filesystem in user space)-based framework, so as to service a FUSE inner module to obtain an I/O (input/output) request generated by an upper-layer user operating a virtual machine, and convert the direct storage of the virtual machine mirror image files into the storage based on the CAS method. The method for eliminating the repetitive data based on the CAS has the advantages that the occupation amount of disks of the vertical machine mirror images is reduced by more than 50%, and the application prospect is wide for the current states of the large-scale application of the existing virtual machine.

The invention relates to a light-weight authentication key negotiation method based on an implicit certificate, and belongs to the technical field of identity authentication. The method is used for establishing a secure channel between an OPC UA server and an OPC UA client and generating of a session key. Three entities, a credible certification authority (CA), the OPC UA client A and the OPC UA server B, are involved in an authentication key negotiation process. The OPC UA server B and the OPC UA client A acquire the own implicit certificates after the CA completes identity registration. Then the OPC UA server B and the OPC UA client A complete bidirectional authentication and key negotiation between the entities by using a light-weight algorithm. According to the method provided by the invention, the light-weight authentication key negotiation method based on the implicit certificate is provided aiming at the problem that an existing OPC UA security mechanism is not applicable to a resource-constrained communication environment. The method provided by the invention can be efficiently and safely applicable to an industrial network with a large amount of resource-constrained embedded OPC UA equipment.