The grid technology is recognized as the next generation of Internet and becomcs the center of recent researches in the computer society. Security is one of the most crucial issues to address in Internet and is of the...The grid technology is recognized as the next generation of Internet and becomcs the center of recent researches in the computer society. Security is one of the most crucial issues to address in Internet and is of the same importance in the application of grid technology. As a critical component of grid security, the secure authen- tication needs to be well studied. In this paper, a two-step mobile agent based（TSMAB） authentication architecture is proposed based on Globus security infrastructure （GSI）. By using mobile agent （MA） technology, the TSMAB authentication architecture is composed of the junior-authentication and the senior-authentication. Based on the design and the analysis of TSMAB model, the result shows that the efficiency of grid authentication is improved compared with the GSI authentication.展开更多
Quantum chemical calculations are performed to study the reactions of OH and ozone with- out and with water to estimate whether the single water molecule can decrease the energy barrier of the OH radical reaction with...Quantum chemical calculations are performed to study the reactions of OH and ozone with- out and with water to estimate whether the single water molecule can decrease the energy barrier of the OH radical reaction with ozone. The calculated results demonstrate that the single water molecule can reduce the activated barrier of the naked OH＋Oa reaction with the value of about 4.18 kJ/mol. In addition, the transition state theory is carried out to determine whether the single water molecule could enhance the rate constant of the OH＋O3 reaction. The computed kinetic data indicate that the rate of the ozone reaction with the formed complexes between OH and water is much slower than that of the OH＋O3 reaction, whereas the rate constant of OH reaction with the formed H20---Oa complex is 2 times greater than that of the naked OH radical with ozone reaction. However, these processes in the atmosphere are not important because the reactions can not compete well with the naked reaction of OH with ozone under atmospheric condition.展开更多
New challenges are introduced when people try to build a general-purpose mobile agent middleware in Grid envi- ronment. In this paper, an instance-oriented security mechanism is proposed to deal with possible security...New challenges are introduced when people try to build a general-purpose mobile agent middleware in Grid envi- ronment. In this paper, an instance-oriented security mechanism is proposed to deal with possible security threats in such mobile agent systems. The current security support in Grid Security Infrastructure (GSI) requires the users to delegate their privileges to certain hosts. This host-oriented solution is insecure and inflexible towards mobile agent applications because it cannot prevent delegation abuse and control well the diffusion of damage. Our proposed solution introduces security instance, which is an en- capsulation of one set of authorizations and their validity specifications with respect to the agent’s specific code segments, or even the states and requests. Applications can establish and configure their security framework flexibly on the same platform, through defining instances and operations according to their own logic. Mechanisms are provided to allow users delegating their identity to these instances instead of certain hosts. By adopting this instance-oriented security mechanism, a Grid-based general-purpose MA middleware, Everest, is developed to enhance Globus Toolkit’s security support for mobile agent applications.展开更多
Driven by an ever-increasing num- ber of new services and applications, transport networks have been undergoing significant changes. In this paper, we describe several ex- citing technology directions associated with ...Driven by an ever-increasing num- ber of new services and applications, transport networks have been undergoing significant changes. In this paper, we describe several ex- citing technology directions associated with future optical transport networks. We review the status of 100G, which is now commercially available and entering volume deployments, and its applications in China. Beyond 100G is considered as the primary technology for the expansion of both channel and fiber capacity in tile near term, and several enabling techniques are introduced. Then, key technologies, prod- ucts, and future evolutionary options of Optical Transport Networks （OTNs） are extensively discussed. Compared to fixed bandwidth and coarse granularity of current WDM network, a flexible grid architecture is a desirable evolu- tion trend, and key technologies and challenges are described. Finally, we illustrate the multi-dimension convergences in terms of IP and optical, Packet OTN （P-OTN）, as well as Electronic Integrated Circuits （EICs） and Photonic Integrated Cimuits （PICs）. Transport networks are therefore in the process of be- coming more broadband, robust, flexible, cost-effective and lower-power-consumptive.展开更多
文摘The grid technology is recognized as the next generation of Internet and becomcs the center of recent researches in the computer society. Security is one of the most crucial issues to address in Internet and is of the same importance in the application of grid technology. As a critical component of grid security, the secure authen- tication needs to be well studied. In this paper, a two-step mobile agent based（TSMAB） authentication architecture is proposed based on Globus security infrastructure （GSI）. By using mobile agent （MA） technology, the TSMAB authentication architecture is composed of the junior-authentication and the senior-authentication. Based on the design and the analysis of TSMAB model, the result shows that the efficiency of grid authentication is improved compared with the GSI authentication.
基金This work was supported by the National Natural Science Foundation of China （No.10865003） and the Science and Technology Foundation of GuiZhou Province, China （No.[201112107）. We thank the Key Laboratory of Guizhou High Performance Computational Chemistry for computer time.
文摘Quantum chemical calculations are performed to study the reactions of OH and ozone with- out and with water to estimate whether the single water molecule can decrease the energy barrier of the OH radical reaction with ozone. The calculated results demonstrate that the single water molecule can reduce the activated barrier of the naked OH＋Oa reaction with the value of about 4.18 kJ/mol. In addition, the transition state theory is carried out to determine whether the single water molecule could enhance the rate constant of the OH＋O3 reaction. The computed kinetic data indicate that the rate of the ozone reaction with the formed complexes between OH and water is much slower than that of the OH＋O3 reaction, whereas the rate constant of OH reaction with the formed H20---Oa complex is 2 times greater than that of the naked OH radical with ozone reaction. However, these processes in the atmosphere are not important because the reactions can not compete well with the naked reaction of OH with ozone under atmospheric condition.
基金Project (No. 602032) supported by the Natural Science Foundationof Zhejiang Province, China
文摘New challenges are introduced when people try to build a general-purpose mobile agent middleware in Grid envi- ronment. In this paper, an instance-oriented security mechanism is proposed to deal with possible security threats in such mobile agent systems. The current security support in Grid Security Infrastructure (GSI) requires the users to delegate their privileges to certain hosts. This host-oriented solution is insecure and inflexible towards mobile agent applications because it cannot prevent delegation abuse and control well the diffusion of damage. Our proposed solution introduces security instance, which is an en- capsulation of one set of authorizations and their validity specifications with respect to the agent’s specific code segments, or even the states and requests. Applications can establish and configure their security framework flexibly on the same platform, through defining instances and operations according to their own logic. Mechanisms are provided to allow users delegating their identity to these instances instead of certain hosts. By adopting this instance-oriented security mechanism, a Grid-based general-purpose MA middleware, Everest, is developed to enhance Globus Toolkit’s security support for mobile agent applications.
基金supported by the National Natural Science Foundation of China under GrantNo. 61171076National 863 Project underGrant No. 2012AA011303National 973 Project under Grant No. 2010CB328200(2010CB328201)
文摘Driven by an ever-increasing num- ber of new services and applications, transport networks have been undergoing significant changes. In this paper, we describe several ex- citing technology directions associated with future optical transport networks. We review the status of 100G, which is now commercially available and entering volume deployments, and its applications in China. Beyond 100G is considered as the primary technology for the expansion of both channel and fiber capacity in tile near term, and several enabling techniques are introduced. Then, key technologies, prod- ucts, and future evolutionary options of Optical Transport Networks （OTNs） are extensively discussed. Compared to fixed bandwidth and coarse granularity of current WDM network, a flexible grid architecture is a desirable evolu- tion trend, and key technologies and challenges are described. Finally, we illustrate the multi-dimension convergences in terms of IP and optical, Packet OTN （P-OTN）, as well as Electronic Integrated Circuits （EICs） and Photonic Integrated Cimuits （PICs）. Transport networks are therefore in the process of be- coming more broadband, robust, flexible, cost-effective and lower-power-consumptive.
