The specialized production of e-commerce transaction systems is an important research topic, which is of great significance for evaluating the development level and forecasting the development direction of e-commerce....The specialized production of e-commerce transaction systems is an important research topic, which is of great significance for evaluating the development level and forecasting the development direction of e-commerce. However, there is a certain disparity between the current mainstream research model and reality, which leads to a deviated result. This paper puts forward a definition of "transaction efficiency" based on essential transaction services and establishes a model of the middleman's specialized production decision of transaction services. The research result shows that (1) transaction efficiency plays an important role in improving the middleman's specialized production level, (2) only when the transaction efficiency is higher than a certain threshold will the distribution middleman appear, and (3) the degree of economic specialization, price of commodities and transaction services, and other associated factors also affect the evolution of e-commerce transaction systems.展开更多
To safeguard the interests of transacting parties,non-repudiation mechanisms need to assure fairness and timeliness.The non-repudiation service currently implemented usually does not consider the requirement of fairne...To safeguard the interests of transacting parties,non-repudiation mechanisms need to assure fairness and timeliness.The non-repudiation service currently implemented usually does not consider the requirement of fairness and the fair non-repudiation protocols to date can not be suitably applied in real environment due to its complex interaction.This paper discusses the transaction-oriented non-repudiation requirement for Web services transaction,analyzes the constraints of the traditional model for the available fair non-repudiation protocols and designs a new Online-TTP fair non-repudiation protocol.The new protocol provides a fair non-repudiation solution to secure Web services transactions and can be embedded into a single Web service call.The protocol adopts evidence chained to decreasing the overhead of evidence verification and management and alleviates the overhead of certificate revocation checking and time-stamp generation for signatures.The protocol has strong fairness,timeliness,efficiency and practicability.展开更多
An active queue management(AQM) algorithm called MCHOKeM is presented,which is borrowed from CHOKeW that draws multi-packets at random from the buffer,the multi-packets are compared with an arriving packet and aband...An active queue management(AQM) algorithm called MCHOKeM is presented,which is borrowed from CHOKeW that draws multi-packets at random from the buffer,the multi-packets are compared with an arriving packet and abandoned if they are from the same flow.But MCHOKeM uses multiple virtual queues for different priority packets and enhances the drawing function by adjusting the maximum number of draws based on the current status of virtual queue length.The number of parameters that MCHOKeM needs to maintain is determined by the number of priority levels being supported by the router,which usually has a small limited value.In order to explain the features of MCHOKeM,an analytical model is used.A series of simulation tests to evaluate the performance are given.展开更多
文摘The specialized production of e-commerce transaction systems is an important research topic, which is of great significance for evaluating the development level and forecasting the development direction of e-commerce. However, there is a certain disparity between the current mainstream research model and reality, which leads to a deviated result. This paper puts forward a definition of "transaction efficiency" based on essential transaction services and establishes a model of the middleman's specialized production decision of transaction services. The research result shows that (1) transaction efficiency plays an important role in improving the middleman's specialized production level, (2) only when the transaction efficiency is higher than a certain threshold will the distribution middleman appear, and (3) the degree of economic specialization, price of commodities and transaction services, and other associated factors also affect the evolution of e-commerce transaction systems.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (2006AA01Z405)
文摘To safeguard the interests of transacting parties,non-repudiation mechanisms need to assure fairness and timeliness.The non-repudiation service currently implemented usually does not consider the requirement of fairness and the fair non-repudiation protocols to date can not be suitably applied in real environment due to its complex interaction.This paper discusses the transaction-oriented non-repudiation requirement for Web services transaction,analyzes the constraints of the traditional model for the available fair non-repudiation protocols and designs a new Online-TTP fair non-repudiation protocol.The new protocol provides a fair non-repudiation solution to secure Web services transactions and can be embedded into a single Web service call.The protocol adopts evidence chained to decreasing the overhead of evidence verification and management and alleviates the overhead of certificate revocation checking and time-stamp generation for signatures.The protocol has strong fairness,timeliness,efficiency and practicability.
基金supported by the Beijing Natural Science Foundation(4102050)USFC-KOSEF Joint Research Project of China and Korea(60811140343)
文摘An active queue management(AQM) algorithm called MCHOKeM is presented,which is borrowed from CHOKeW that draws multi-packets at random from the buffer,the multi-packets are compared with an arriving packet and abandoned if they are from the same flow.But MCHOKeM uses multiple virtual queues for different priority packets and enhances the drawing function by adjusting the maximum number of draws based on the current status of virtual queue length.The number of parameters that MCHOKeM needs to maintain is determined by the number of priority levels being supported by the router,which usually has a small limited value.In order to explain the features of MCHOKeM,an analytical model is used.A series of simulation tests to evaluate the performance are given.