近年来,企业对数据安全的关注程度大大增强,Oracle Data Guard提供高可靠性的数据保护,并可以实现数据的灾难恢复,Oracle Data Guard能将生产数据切换到灾备数据库中,从而减少了由于数据存储而造成的当机时间。Data Guard也能配合备份...近年来,企业对数据安全的关注程度大大增强,Oracle Data Guard提供高可靠性的数据保护,并可以实现数据的灾难恢复,Oracle Data Guard能将生产数据切换到灾备数据库中,从而减少了由于数据存储而造成的当机时间。Data Guard也能配合备份和恢复技术、集群技术提供高层次的数据可靠性,本文主要阐述如何利用Oracle Data Guard的原理及构建灾备的方法。展开更多
In this paper, a novel Home Location Register(HLR) mobility database recovery scheme is proposed. With database backing-up and signal sending as its key processes, the presented scheme is designed for the purpose of b...In this paper, a novel Home Location Register(HLR) mobility database recovery scheme is proposed. With database backing-up and signal sending as its key processes, the presented scheme is designed for the purpose of both decreasing system costs and reducing number of lost calls. In our scheme, an algorithm is developed for an HLR to identify such VLRs that there are new MSs roaming into them since the latest HLR database backing up. The identification of those VLRs is used by the HLR to send Unreliable Roaming Data Directive messages to each of them to get the correct location information of those new MSs. Additionally, two kinds of relationships, one between the number of lost calls and the database backing-up period and the other between the backing-up cost and the period, are well analyzed. Both analytical and numerical results indicate that there will be an optimal HLR database backing-up period if certain system parameters are given and the total cost can be consequently minimized.展开更多
This paper proposes the concept of transaction-type covert storage channels, which are caused by database storage resources. It also proposes that the mode of auditing those channels be based on the transactions. Next...This paper proposes the concept of transaction-type covert storage channels, which are caused by database storage resources. It also proposes that the mode of auditing those channels be based on the transactions. Next, the paper analyzes and resolves the two problems arising from auditing the use of transaction-type covert storage channels in database systems: namely, the relationship between channel variables, which are altered (or viewed) by the transaction and satisfy integrity constraints in DBMS, and database states; and the circumvention of covert storage channel audit in DBMS.展开更多
This paper briefly analyzes the present situation of textile mill＇s air-conditioning system. Since it is difficult to establish detailed math model to control a textile mill＇s airconditioning system because of the i...This paper briefly analyzes the present situation of textile mill＇s air-conditioning system. Since it is difficult to establish detailed math model to control a textile mill＇s airconditioning system because of the influence of various factors such as the differences in seasons, regions, etc., most air-conditioning equipment can not be controlled automatically. This paper suggests utilizing multi-function data acquisRion card to collect the data about the temperature and humidity of a workshop, processing the data on a PC, comparing them with the expert database, and then using the 485 serial port expanding module to output the parameters, which are used to control the inverter, so that the purpose of adjusting the temperature and humidity of the workshop is achieved.展开更多
The experiment platform of the aeroengine badly needs to develope in the direction of the overall supporting, the database system management and the engineering practice. Experimental means such as the water, electric...The experiment platform of the aeroengine badly needs to develope in the direction of the overall supporting, the database system management and the engineering practice. Experimental means such as the water, electricity and gas systems which support the operation of equipment, and multiple sets of engine components （the compressor, the turbine, the combustion chamber, the structural strength etc.） which support the experimental study of the engine also badly needs to improve in the direction of comprehensive monitoring and system integration to meet the needs of high efficient experiment and management. The experiment platform can make the experimental data and the experimental process be shared in different places in real time. Improving the collaborative ability of design and experiment, improving the automatic level of the experiment and so on all need the computer, the network and the professional and matching application system to support so as to guarantee the security, the stability and the reliability of the experiment, and reduce the risk of the experiment. This paper mainly discusses the main innovative exploration of experimental platform and equipment development about the current aeroengine.展开更多
文摘近年来,企业对数据安全的关注程度大大增强,Oracle Data Guard提供高可靠性的数据保护,并可以实现数据的灾难恢复,Oracle Data Guard能将生产数据切换到灾备数据库中,从而减少了由于数据存储而造成的当机时间。Data Guard也能配合备份和恢复技术、集群技术提供高层次的数据可靠性,本文主要阐述如何利用Oracle Data Guard的原理及构建灾备的方法。
基金the National 863 Program(No.MII-C3G-02-20/863-317-03-01-02-20)
文摘In this paper, a novel Home Location Register(HLR) mobility database recovery scheme is proposed. With database backing-up and signal sending as its key processes, the presented scheme is designed for the purpose of both decreasing system costs and reducing number of lost calls. In our scheme, an algorithm is developed for an HLR to identify such VLRs that there are new MSs roaming into them since the latest HLR database backing up. The identification of those VLRs is used by the HLR to send Unreliable Roaming Data Directive messages to each of them to get the correct location information of those new MSs. Additionally, two kinds of relationships, one between the number of lost calls and the database backing-up period and the other between the backing-up cost and the period, are well analyzed. Both analytical and numerical results indicate that there will be an optimal HLR database backing-up period if certain system parameters are given and the total cost can be consequently minimized.
文摘This paper proposes the concept of transaction-type covert storage channels, which are caused by database storage resources. It also proposes that the mode of auditing those channels be based on the transactions. Next, the paper analyzes and resolves the two problems arising from auditing the use of transaction-type covert storage channels in database systems: namely, the relationship between channel variables, which are altered (or viewed) by the transaction and satisfy integrity constraints in DBMS, and database states; and the circumvention of covert storage channel audit in DBMS.
文摘This paper briefly analyzes the present situation of textile mill＇s air-conditioning system. Since it is difficult to establish detailed math model to control a textile mill＇s airconditioning system because of the influence of various factors such as the differences in seasons, regions, etc., most air-conditioning equipment can not be controlled automatically. This paper suggests utilizing multi-function data acquisRion card to collect the data about the temperature and humidity of a workshop, processing the data on a PC, comparing them with the expert database, and then using the 485 serial port expanding module to output the parameters, which are used to control the inverter, so that the purpose of adjusting the temperature and humidity of the workshop is achieved.
文摘The experiment platform of the aeroengine badly needs to develope in the direction of the overall supporting, the database system management and the engineering practice. Experimental means such as the water, electricity and gas systems which support the operation of equipment, and multiple sets of engine components （the compressor, the turbine, the combustion chamber, the structural strength etc.） which support the experimental study of the engine also badly needs to improve in the direction of comprehensive monitoring and system integration to meet the needs of high efficient experiment and management. The experiment platform can make the experimental data and the experimental process be shared in different places in real time. Improving the collaborative ability of design and experiment, improving the automatic level of the experiment and so on all need the computer, the network and the professional and matching application system to support so as to guarantee the security, the stability and the reliability of the experiment, and reduce the risk of the experiment. This paper mainly discusses the main innovative exploration of experimental platform and equipment development about the current aeroengine.
