Assuming that the realized demand is determined by the inventory level,a two-part revenue sharing contract of one supplier and one retailer is analyzed under the circumstance of demand disruption(the disruption cost o...Assuming that the realized demand is determined by the inventory level,a two-part revenue sharing contract of one supplier and one retailer is analyzed under the circumstance of demand disruption(the disruption cost occurs at the supplier).Based on the centralized optimization,the profits of the two members are maximized in sequential optimization though a two-part revenue-sharing contract.The result shows that when the demand disruption occurs,if the degree of disruption is within some range,the ordering and manufacturing plans need not be changed,while only the revenue sharing fraction for the retailer should be diminished;if not,both the plan and the revenue sharing fraction should be changed for the possible coordination of the supply chain.Finally,numerical illustrations of the contract for various scenarios are given.展开更多
An approach of defending against Distributed Denial of Service (DDoS) attack based on flow model and flow detection is presented. The proposed approach can protect targets from DDoS attacking, and allow targets to pro...An approach of defending against Distributed Denial of Service (DDoS) attack based on flow model and flow detection is presented. The proposed approach can protect targets from DDoS attacking, and allow targets to provide good service to legitimate traffic under DDoS attacking, with fast reaction. This approach adopts the technique of dynamic comb filter, yields a low level of false positives of less than 1.5%, drops similar percentage of good traffic, about 1%, and passes neglectable percentage of attack bandwidth to the victim, less than 1.5%. The prototype of commercial product, D-fighter, is developed by implementing this proposed approach on Intel network processor platform IXP1200.展开更多
Multimedia streaming served through peer-to-peer (P2P) networks is booming nowadays. However, the end-to-end streaming quality is generally unstable due to the variability of the state of serve-peers. On the other han...Multimedia streaming served through peer-to-peer (P2P) networks is booming nowadays. However, the end-to-end streaming quality is generally unstable due to the variability of the state of serve-peers. On the other hand, proxy caching is a bandwidth-efficient scheme for streaming over the Internet, whereas it is a substantially expensive method needing dedicated powerful proxy servers. In this paper, we present a P2P cooperative streaming architecture combined with the advantages of both P2P networks and multimedia proxy caching techniques to improve the streaming quality of participating clients. In this frame- work, a client will simultaneously retrieve contents from the server and other peers that have viewed and cached the same title before. In the meantime, the client will also selectively cache the aggregated video content so as to serve still future clients. The associate protocol to facilitate the multi-path streaming and a distributed utility-based partial caching scheme are detailedly dis- cussed. We demonstrate the effectiveness of this proposed architecture through extensive simulation experiments on large, Inter- net-like topologies.展开更多
Network traffic classification plays an important role and benefits many practical network issues,such as Next-Generation Firewalls(NGFW),Quality of Service(QoS),etc.To face the challenges brought by modern high speed...Network traffic classification plays an important role and benefits many practical network issues,such as Next-Generation Firewalls(NGFW),Quality of Service(QoS),etc.To face the challenges brought by modern high speed networks,many inspiring solutions have been proposed to enhance traffic classification.However,taking many factual network conditions into consideration,e.g.,diversity of network environment,traffic classification methods based on Deep Inspection(DI) technique still occupy the top spot in actual usage.In this paper,we propose a novel classification system employing Deep Inspection technique,aiming to achieve Parallel Protocol Parsing(PPP).We start with an analytical study of the existing popular DI methods,namely,regular expression based methods and protocol parsing based methods.Motivated by their relative merits,we extend traditional protocol parsers to achieve parallel matching,which is the representative merit of regular expression.We build a prototype system,and evaluation results show that significant improvement has been made comparing to existing open-source solutions in terms of both memory usage and throughput.展开更多
The main purpose of this paper was to set up a functioning numerical model of data rack verified by an experimental measurement. The numerical model will serve for the flow simulation inside the data rack. For the aim...The main purpose of this paper was to set up a functioning numerical model of data rack verified by an experimental measurement. The numerical model will serve for the flow simulation inside the data rack. For the aim of experimental verification of the server model, a PIV （particle image velocimetry） method was used. The server model was projected based on the original Rack Workstation Dell Precision 17,5400 （2U rack space）. The flow rate in each channel was implemented with the help of pressure loss, which was set up so that the server flow rate corresponded with the measured values. The verification of the correct functioning of the numerical model of the server was carded out together with verifying the numerical model of a small data rack. The experiment was compared with the numerical model for the case of data rack （12U rack space） fitted with two 2U rack workstations Dell Precision R5400, on which the simulation of several phases of the entire data rack with given configuration was carried out.展开更多
Mobile agents are able to migrate among machines to achieve their tasks. This feature is attractive to design, implement, and maintain distributed systems because we can implement both client-side and server-side prog...Mobile agents are able to migrate among machines to achieve their tasks. This feature is attractive to design, implement, and maintain distributed systems because we can implement both client-side and server-side programming in one mobile agent. However, it involves the increase of data traffic for mobile agent migrations. In this paper, we propose program code caching to reduce the data traffic caused by mobile agent migrations. A mobile agent consists of many program codes that define a task executed in each machine they migrate; thus, the mobile agent migration involves the transfer of their program codes. Therefore, our method reduces the number of the transfer of program codes by using program code cache. We have implemented our method on a mobile agent framework called Maglog and conducted experiments on a meeting scheduling system.展开更多
The rapid development of cross-border e-commerce has brought a potentially huge market. But due to the complexity of logistics, capital flow, the credit mechanism is involved in cross-border electronic commerce, a ser...The rapid development of cross-border e-commerce has brought a potentially huge market. But due to the complexity of logistics, capital flow, the credit mechanism is involved in cross-border electronic commerce, a serious impediment to the further development of China＇s cross-border B2C e-commerce enterprises. In order to better promote the development of cross-border e-commerce, improve the competitiveness of cross-border e-commerce and logistics services, we must pay attention to the construction of cross-border logistics. Therefore, it can be improved and perfected through logistics control, personnel training and so on.展开更多
Mobile cloud computing （MCC） has become a promising technique to deal with computation- or data-intensive tasks. It overcomes the limited processing power, poor storage capacity, and short battery life of mobile dev...Mobile cloud computing （MCC） has become a promising technique to deal with computation- or data-intensive tasks. It overcomes the limited processing power, poor storage capacity, and short battery life of mobile devices. Providing continuous and on-demand services, MCC argues that the service must be available for users at anytime and anywhere. However, at present, the service availability of MCC is usually measured by some certain metrics of a real-world system, and the results do not have broad representation since different systems have different load levels, different deployments, and many other random factors. Meanwhile, for large-scale and complex types of services in MCC systems, simulation-based methods （such as Monte- Carlo simulation） may be costly and the traditional state-based methods always suffer from the problem of state-space explosion. In this paper, to overcome these shortcomings, fluid-flow approximation, a breakthrough to avoid state-space explosion, is adopted to analyze the service availability of MCC. Four critical metrics, including response time of service, minimum sensing time of devices, minimum number of nodes chosen, and action throughput, are def＇med to estimate the availability by solving a group of ordinary differential equations even before the MCC system is fully deployed. Experimental results show that our method costs less time in analyzing the service availability of MCC than the Markov- or simulation-based methods.展开更多
基金The National Key Technology R&D Program of China during the 11th Five-Year Plan Period(No.2006BAH02A06)
文摘Assuming that the realized demand is determined by the inventory level,a two-part revenue sharing contract of one supplier and one retailer is analyzed under the circumstance of demand disruption(the disruption cost occurs at the supplier).Based on the centralized optimization,the profits of the two members are maximized in sequential optimization though a two-part revenue-sharing contract.The result shows that when the demand disruption occurs,if the degree of disruption is within some range,the ordering and manufacturing plans need not be changed,while only the revenue sharing fraction for the retailer should be diminished;if not,both the plan and the revenue sharing fraction should be changed for the possible coordination of the supply chain.Finally,numerical illustrations of the contract for various scenarios are given.
基金Supported by the National High Technology Research and Development Program of China (863 Program)(No.2003AA142080, 2005AA775060)the National Natural Sicence Foundation of China(No.60203004)National Basic Research Program of China (973Program) (No.2003CB314805)the National Outstanding Youth Foundation (No.60325102)
文摘An approach of defending against Distributed Denial of Service (DDoS) attack based on flow model and flow detection is presented. The proposed approach can protect targets from DDoS attacking, and allow targets to provide good service to legitimate traffic under DDoS attacking, with fast reaction. This approach adopts the technique of dynamic comb filter, yields a low level of false positives of less than 1.5%, drops similar percentage of good traffic, about 1%, and passes neglectable percentage of attack bandwidth to the victim, less than 1.5%. The prototype of commercial product, D-fighter, is developed by implementing this proposed approach on Intel network processor platform IXP1200.
基金Project (Nos. 90412012 and 60673160) supported by the NationalNatural Science Foundation of China
文摘Multimedia streaming served through peer-to-peer (P2P) networks is booming nowadays. However, the end-to-end streaming quality is generally unstable due to the variability of the state of serve-peers. On the other hand, proxy caching is a bandwidth-efficient scheme for streaming over the Internet, whereas it is a substantially expensive method needing dedicated powerful proxy servers. In this paper, we present a P2P cooperative streaming architecture combined with the advantages of both P2P networks and multimedia proxy caching techniques to improve the streaming quality of participating clients. In this frame- work, a client will simultaneously retrieve contents from the server and other peers that have viewed and cached the same title before. In the meantime, the client will also selectively cache the aggregated video content so as to serve still future clients. The associate protocol to facilitate the multi-path streaming and a distributed utility-based partial caching scheme are detailedly dis- cussed. We demonstrate the effectiveness of this proposed architecture through extensive simulation experiments on large, Inter- net-like topologies.
基金supported by the National Key Technology R&D Program of China under Grant No.2012BAH46B04
文摘Network traffic classification plays an important role and benefits many practical network issues,such as Next-Generation Firewalls(NGFW),Quality of Service(QoS),etc.To face the challenges brought by modern high speed networks,many inspiring solutions have been proposed to enhance traffic classification.However,taking many factual network conditions into consideration,e.g.,diversity of network environment,traffic classification methods based on Deep Inspection(DI) technique still occupy the top spot in actual usage.In this paper,we propose a novel classification system employing Deep Inspection technique,aiming to achieve Parallel Protocol Parsing(PPP).We start with an analytical study of the existing popular DI methods,namely,regular expression based methods and protocol parsing based methods.Motivated by their relative merits,we extend traditional protocol parsers to achieve parallel matching,which is the representative merit of regular expression.We build a prototype system,and evaluation results show that significant improvement has been made comparing to existing open-source solutions in terms of both memory usage and throughput.
文摘The main purpose of this paper was to set up a functioning numerical model of data rack verified by an experimental measurement. The numerical model will serve for the flow simulation inside the data rack. For the aim of experimental verification of the server model, a PIV （particle image velocimetry） method was used. The server model was projected based on the original Rack Workstation Dell Precision 17,5400 （2U rack space）. The flow rate in each channel was implemented with the help of pressure loss, which was set up so that the server flow rate corresponded with the measured values. The verification of the correct functioning of the numerical model of the server was carded out together with verifying the numerical model of a small data rack. The experiment was compared with the numerical model for the case of data rack （12U rack space） fitted with two 2U rack workstations Dell Precision R5400, on which the simulation of several phases of the entire data rack with given configuration was carried out.
文摘Mobile agents are able to migrate among machines to achieve their tasks. This feature is attractive to design, implement, and maintain distributed systems because we can implement both client-side and server-side programming in one mobile agent. However, it involves the increase of data traffic for mobile agent migrations. In this paper, we propose program code caching to reduce the data traffic caused by mobile agent migrations. A mobile agent consists of many program codes that define a task executed in each machine they migrate; thus, the mobile agent migration involves the transfer of their program codes. Therefore, our method reduces the number of the transfer of program codes by using program code cache. We have implemented our method on a mobile agent framework called Maglog and conducted experiments on a meeting scheduling system.
文摘The rapid development of cross-border e-commerce has brought a potentially huge market. But due to the complexity of logistics, capital flow, the credit mechanism is involved in cross-border electronic commerce, a serious impediment to the further development of China＇s cross-border B2C e-commerce enterprises. In order to better promote the development of cross-border e-commerce, improve the competitiveness of cross-border e-commerce and logistics services, we must pay attention to the construction of cross-border logistics. Therefore, it can be improved and perfected through logistics control, personnel training and so on.
基金Project supported by the National Natural Science Foundation of China （Nos. 61402127 and 61370212） and the Natural Science Foundation of Heilongjiang Province, China （No. F2015029）
文摘Mobile cloud computing （MCC） has become a promising technique to deal with computation- or data-intensive tasks. It overcomes the limited processing power, poor storage capacity, and short battery life of mobile devices. Providing continuous and on-demand services, MCC argues that the service must be available for users at anytime and anywhere. However, at present, the service availability of MCC is usually measured by some certain metrics of a real-world system, and the results do not have broad representation since different systems have different load levels, different deployments, and many other random factors. Meanwhile, for large-scale and complex types of services in MCC systems, simulation-based methods （such as Monte- Carlo simulation） may be costly and the traditional state-based methods always suffer from the problem of state-space explosion. In this paper, to overcome these shortcomings, fluid-flow approximation, a breakthrough to avoid state-space explosion, is adopted to analyze the service availability of MCC. Four critical metrics, including response time of service, minimum sensing time of devices, minimum number of nodes chosen, and action throughput, are def＇med to estimate the availability by solving a group of ordinary differential equations even before the MCC system is fully deployed. Experimental results show that our method costs less time in analyzing the service availability of MCC than the Markov- or simulation-based methods.
