This paper analyzed the security of a database considering the environment of distributed *** are several security mechanisms that are applied to the different types of data that are saved;this research identifies sev...
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This paper analyzed the security of a database considering the environment of distributed *** are several security mechanisms that are applied to the different types of data that are saved;this research identifies several problems for mitigating the security of a distributed *** objective is to define a basic scheme and an abstract algorithm through algorithms using flowchart techniques for a security process in a *** deductive method and the exploratory investigation were used to analyze the information of the articles of the *** resulted in a basic structure based on a three-level architecture,with 3 DES encryption algorithm applied to the request and response;SQL-based encryption for data processing;FPE encryption algorithm for storage in the database;the scheme was presented with its scope and possible limitations;and a prototype of an abstract algorithm expressed with flowchart techniques was *** was concluded that the basic scheme and abstract algorithm presented as an alternative to control access to resources,to provide improved security in a distributed database.
In distributed database system,the distributed deposition and redundancy data brought convenient to fault recovery,but they make distributed query processing more complicated at the same *** optimization and processin...
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In distributed database system,the distributed deposition and redundancy data brought convenient to fault recovery,but they make distributed query processing more complicated at the same *** optimization and processing is one of the key technologies in distributed database *** generally uses semi-join operation to improve the time response performance of query and reduce communication *** paper briefly described the corresponding concepts and characteristics of distributed database system,summarized the goals of distributed database query optimization,and analyzed the query optimization process based on semi-join operation combined with the practical *** addition,it introduced a classical algorithm which is used for multiple connection and query optimization based on the semi-join query optimization,the SDD-1 algorithm.
This essay studies on the data distribution methods in the distributed *** the current methods of data distribution in distributed database,the problems in the distribution methods such as limitations,complex cost for...
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This essay studies on the data distribution methods in the distributed *** the current methods of data distribution in distributed database,the problems in the distribution methods such as limitations,complex cost formula,low running efficiency of the algorithm and so on lead to that the calculation results are quite different from the optimal distribution ***,this essay proposes a method to apply genetic algorithm in the data distribution in the distributed *** also carries out some improvements in the genetic algorithm:improvement in initializing colony,comprehensive mechanism of fitness ratio and optimal value reserve,the use of self-regulating cross factor and self-regulating variation *** improvements further increase the accuracy of the data distribution and the calculation *** simulation experiment in this distribution method,the result has shown that the result of the data distribution method obtained in this essay is the closest to the best *** the performance is better than the commonly used data distribution method based on data segment access features and so on.
This paper analyzed the characteristics and requests of trust investment synthesized business system,and then designed and implemented a distributed database based on *** design and implementation were the embodiment ...
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This paper analyzed the characteristics and requests of trust investment synthesized business system,and then designed and implemented a distributed database based on *** design and implementation were the embodiment of the distributed database technology,which assured the security, reliability and flexibility of the database.
distributed database query optimization is very important in business field. This paper proposes an optimization based on genetic algorithm and immune theory. distributed database query is optimized by genetic coding ...
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distributed database query optimization is very important in business field. This paper proposes an optimization based on genetic algorithm and immune theory. distributed database query is optimized by genetic coding and immune vaccine construction. Then, through the experimental data test, it proves that the algorithm has 13% higher efficiency than the standard genetic algorithm, which shows that the algorithm has better performance.
In this paper,we have given a specification of a distributed algorithm using the process algebraμ*** algorithm is about how preserving the data replication consistency in a distributed database arranged as ring,where...
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In this paper,we have given a specification of a distributed algorithm using the process algebraμ*** algorithm is about how preserving the data replication consistency in a distributed database arranged as ring,where each node is attributed a unique integer as *** update emitted by a node with greater priority cancels the one emitted by a node with less priority when propagating on this last,while an update originated from a node with less priority will be stopped at a node with greater *** strategy has been proven valid by Roscoe et *** algorithm that we have specified by mean of the process algebra is simplified: each node is supposed to update only one *** have given formal definitions of both the process running at a node and the global behavior of the system in the process algebra,and verified that the specification is well-formed using the utilities of the uCRL tool set.
This paper proposes a distributed data clustering technique based on deep neural network. First, each record in the distributed database is taken as an input vector, and its characteristics are extracted and input to ...
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This paper proposes a distributed data clustering technique based on deep neural network. First, each record in the distributed database is taken as an input vector, and its characteristics are extracted and input to the input layer of the depth neural network. The weight of the connection is trained by BP algorithm, and the training of depth neural network output is realized by adjusting the weight. Finally, the data clustering results are judged according to the similarity of the current vector corresponding to the output data. Experimental results based on small-scale distributed systems show that this method has better test set accuracy than traditional k-means clustering method, and is more suitable for large-scale data clustering in the distributed environments.
The existing distributed database is mainly based on the limited scale network environment. Many systems implement algorithms are difficult to apply when it needs to be expanded or involved into the field of distribut...
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The existing distributed database is mainly based on the limited scale network environment. Many systems implement algorithms are difficult to apply when it needs to be expanded or involved into the field of distributed query processing, distributed transaction processing and data replication. In this paper, one real-time transaction management architecture and its details are proposed to improve the efficacy of SQL processing based on distributed database system. The seven primary functional models in the server cluster part and four functional models in the distributed database part are designed to enhance the query function such as insert or update in our network environment. The experiments and results proved that our method is more efficient than traditional methods.
In this paper, a new application of colour timed Petri net (CTPN) based methodology for distributed relational database queries modeling and corresponding simulation is addressed. This work, first based on parsed quer...
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In this paper, a new application of colour timed Petri net (CTPN) based methodology for distributed relational database queries modeling and corresponding simulation is addressed. This work, first based on parsed query definitions, converts logical query plans into designed CTPN models. Later, the improved cost-based functions are then established and appended to CTPN with a general purpose CPN simulator-Design/CPN to observe the thresholds of query operations. The propose CTPN can be used in the design phase as an experimental prototype to automatically simulate distributed database query processing which, in turn, may considerably reduce the load of developing the actual query processing software in the logical design phase of a distributed database system. Also, since all the essential details of query processing in CTPN have been simulated, the results of this study can be closely related to real world applications.
This paper describes a distributed database system implementation built on top of stand-alone mobile databases found on mobile devices. At the heart of the architecture are elected devices that take on the role of dat...
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This paper describes a distributed database system implementation built on top of stand-alone mobile databases found on mobile devices. At the heart of the architecture are elected devices that take on the role of data directories which collect the schema of the databases and become the contact points for all nodes that wish to submit queries against the distributed database. The system is implemented on Pocket PCs that run the Microsoft WinCE operating system and communicate using Bluetooth, thus limiting the architecture to eight devices, which is a restriction imposed by piconets. Sample databases were configured on the devices that ran the SQL Server CE database engine, and a list of 170 sample queries of varying complexities were designed to conduct performance evaluation. This evaluation involved measurement of query response time, generated traffic, and device energy consumption. The obtained results indicated the feasibility of the system and its potential for providing mobile users with a framework for aggregating disparate data that are stored in mobile databases in the wireless ad hoc network. (C) 2008 Elsevier Ltd. All rights reserved.
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