Secure interaction and interoperability between two or more administrative domains is a major concern. The IRBAC 2000 model accomplishes secure interaction and interoperability by flexibly dynamic inter-domain role tr...
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Secure interaction and interoperability between two or more administrative domains is a major concern. The IRBAC 2000 model accomplishes secure interaction and interoperability by flexibly dynamic inter-domain role translations. Associations are the key element of the IRBAC 2000 model, which have a great impact on security and efficiency of dynamic role translations. Therefore, it is a crucial problem how to manage the associations in the IRBAC 2000 model. There are two cases under which some matters will emerge. One is where conflicting associations may result in a security hazard. Another is where redundant associations may reduce the efficiency of dynamic role translations and increase the difficulty of management of associations. The formal definitions on conflicting associations and redundant associations are given, and the methods are discusses to judge whether there are conflicting associations or redundant associations in IRBAC 2000 model. The protective mechanism is presented, which utilizes prerequisite conditions to prevent conflicting or redundant associations from appearing in IRBAC 2000 model.
The compositions of copolymers of diethyldiallylammonium chloride （DEDAAC） with acrylamide （AM）, acrylic acid （AA） or sodium acrylic acid （NaAA） at low conversion were determined by elemental analysis, and the...
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The compositions of copolymers of diethyldiallylammonium chloride （DEDAAC） with acrylamide （AM）, acrylic acid （AA） or sodium acrylic acid （NaAA） at low conversion were determined by elemental analysis, and the reactivity ratios of monomers in copolymerization were obtained by Kelen-Tudos method. The results showed that the reactivity ratios rDE and rAM are 0.31 and 5.27 for DEDAAC with AM, rDE and rAA are 0.28 and 5.15 for DEDAAC with AA, and roe and rNsAA are 0.40 and 3.97 for DEDAAC with NaAA, respectively. The copolymerizations for DEDAAC with AM, AA or NaAA are non-ideal copolymerization and the products are random copolymers.
In wireless sensor network, in-network data aggregation can eliminate redundancy, improve data accuracy and thus prolong the lifetime of network However, most of data aggregation technologies assumed that the aggregat...
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For the purpose of increasing ventilation rate but without increasing energy consumption, a novel fresh air handling unit is proposed, which is characteristically composed of three rotary wheels called as total heat w...
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ISBN:
(纸本)9789899506718
For the purpose of increasing ventilation rate but without increasing energy consumption, a novel fresh air handling unit is proposed, which is characteristically composed of three rotary wheels called as total heat wheel, desiccant wheel, and sensible heat wheel respectively. To evaluate the energy saving potential of the proposed three-rotary wheels fresh air handling unit (TRWFAHU), its mathematical model is built. Using its mathematical model, the AHU is numerically simulated with hourly weather data of Changsha. Compared with conventional fresh air handling unit, TRWFAHU can save 10.2% of primary energy and greatly decrease energy consumption of chiller. If waste heat is available to regenerate desiccant, the proposed AHU can achieve greater energy saving. It is achievable to improve IAQ by increasing ventilation while without increasing energy consumption if TRWFAHU is used to handle outdoor air.
In this paper, a Structure Health Monitor (SHM) System for the bridge is introduced, of which wireless communication and embedding techniques are deployed. After summing up the wireless communication techniques and ti...
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A new conception of full digital control and amplifier system for magnetic levitating bearing is *** needs good performances such as high control precision,fast response,low noise and high stability,so magnetic levita...
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The main factors that affect infrared surveying in roadway include that property of rock, electromechanical equipments running, environmental temperature, hydrogeology and support material etc. This paper sums up the ...
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The main factors that affect infrared surveying in roadway include that property of rock, electromechanical equipments running, environmental temperature, hydrogeology and support material etc. This paper sums up the expression features of these disturbing factor through theoretical analysis and actual measurement contrasts and considers that some tunnel section does not suit to go on infrared survey, for instance, soft rock meets water to expanse, and surround rock has obviously pouring water. The basic methods had made evading disturbing of electromechanical equipments, environmental temperature and protect material etc to become possible. It is helpful that offers infrared surveying technical service for production safety better in roadway.
The remote configuration of Intelligent Electronic Devices (IED) is an important safety, reliability related function in substation automation systems. With the issue of IEC 61850 standard, the Substation Configuratio...
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ISBN:
(纸本)0863416381
The remote configuration of Intelligent Electronic Devices (IED) is an important safety, reliability related function in substation automation systems. With the issue of IEC 61850 standard, the Substation Configuration description Language (SCL) based on XML can be an effective solution for IED description and configuration. The realization of remote configuration must be established on the foundation of security communication channel, but conventional cyber-security technologies like IPSec, SSL are not enough for the protection of SCL files. This paper presents a security mechanism based on XML Security, definng an extended schema for SCL security, guaranteing the integrality and authentication of both communication ends through the signature for SCL files, protecting the SCL elements for multi-granularity confidentiality through the symmetrical key encryption. A SCLSec system with this security mechanism is desiged for remote configuration. On the study of a remote configuration instance, the SCLSec system can meet the demands of security requirements and is suitable for the applications in substation automation system. The work is based on the standards of information security and power engineering. It is not conflicting with the progressing work of IEC TC57 WG15 and can provide useful supplement.
This paper deals with the robust fuzzy control for chaotic systems in the presence of parametric uncertainties. An uncertain Takagi-Sugeno fuzzy model for a Lorenz chaotic system is first constructed. Then a robust fu...
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This paper deals with the robust fuzzy control for chaotic systems in the presence of parametric uncertainties. An uncertain Takagi-Sugeno fuzzy model for a Lorenz chaotic system is first constructed. Then a robust fuzzy state feedback control scheme ensures the control for stable operations under bounded parametric uncertainties. For a chaotic system with known uncertainty bounds, a robust fuzzy regulator is designed by choosing the control parameters satisfying the linear matrix inequality. To verify the validity and effectiveness of the proposed controller design method, an analysis technique is suggested and applied to the control of an uncertain Lorenz chaotic system.
This paper studies the robust fuzzy control for nonlinear chaotic system in the presence of parametric uncertainties. An uncertain Takagi-Sugeno （T-S） fuzzy model is employed for fuzzy modelling of an unknown chaoti...
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This paper studies the robust fuzzy control for nonlinear chaotic system in the presence of parametric uncertainties. An uncertain Takagi-Sugeno （T-S） fuzzy model is employed for fuzzy modelling of an unknown chaotic system. A sufficient condition formulated in terms of linear matrix inequality （LMI） for the existence of fuzzy controller is obtained. Then the output feedback fuzzy-model-based regulator derived from the LMI solutions can guarantee the stability of the closed-loop overall fuzzy system. The T-S fuzzy model of the chaotic Chen system is developed as an example for illustration. The effectiveness of the proposed controller design methodology is finally demonstrated through computer simulations on the uncertain Chen chaotic system.
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