To reduce network redundancy,innetwork caching is considered in many future Internet architectures,such as Information Centric Networking.In in-network caching system,the item sojourn time of LRU(Least Recently Used) ...To reduce network redundancy,innetwork caching is considered in many future Internet architectures,such as Information Centric Networking.In in-network caching system,the item sojourn time of LRU(Least Recently Used) replacement policy is an important issue for two reasons:firstly,LRU is one of the most common used cache policy;secondly,item sojourn time is positively correlated to the hit probability,so this metric parameter could be useful to design the caching system.However,to the best of our knowledge,the sojourn time hasn't been studied theoretically so far.In this paper,we first model the LRU cache policy by Markov chain.Then an approximate closedform expression of the item expectation sojourn time is provided through the theory of stochastic service system,which is a function of the item request rates and cache size.Finally,extensive simulation results are illustrated to show that the expression is a good approximation of the item sojourn time.展开更多
An integrated pest management model of Cost/Benefit analysis strategy was constructed for stem corn borer Sesamia cretica using complementary control measures of different resistant genotypes of corn with the chemical...An integrated pest management model of Cost/Benefit analysis strategy was constructed for stem corn borer Sesamia cretica using complementary control measures of different resistant genotypes of corn with the chemical insecticide diazinon 60%. Based on Cost/Benefit analysis result, the resistant genotype （SAKHA 9433） provides maximum economic value of production at the model point where no spray of insecticide is applied. The applications of one or two sprays do not justify the use of chemical insecticide but rather result in economic loss since the reduction in borer damage value, due to diazinon use, is lower than the cost of control （spray）. However, the applications of one spray for the moderate resistant genotype （IPA 2052） and two sprays for the sensitive genotype （CML 323） during corn growing season would be of value to cover the cost of control （spray） but do not achieve similar economic value of revenue comparing with the resistant genotype.展开更多
文摘To reduce network redundancy,innetwork caching is considered in many future Internet architectures,such as Information Centric Networking.In in-network caching system,the item sojourn time of LRU(Least Recently Used) replacement policy is an important issue for two reasons:firstly,LRU is one of the most common used cache policy;secondly,item sojourn time is positively correlated to the hit probability,so this metric parameter could be useful to design the caching system.However,to the best of our knowledge,the sojourn time hasn't been studied theoretically so far.In this paper,we first model the LRU cache policy by Markov chain.Then an approximate closedform expression of the item expectation sojourn time is provided through the theory of stochastic service system,which is a function of the item request rates and cache size.Finally,extensive simulation results are illustrated to show that the expression is a good approximation of the item sojourn time.
文摘An integrated pest management model of Cost/Benefit analysis strategy was constructed for stem corn borer Sesamia cretica using complementary control measures of different resistant genotypes of corn with the chemical insecticide diazinon 60%. Based on Cost/Benefit analysis result, the resistant genotype （SAKHA 9433） provides maximum economic value of production at the model point where no spray of insecticide is applied. The applications of one or two sprays do not justify the use of chemical insecticide but rather result in economic loss since the reduction in borer damage value, due to diazinon use, is lower than the cost of control （spray）. However, the applications of one spray for the moderate resistant genotype （IPA 2052） and two sprays for the sensitive genotype （CML 323） during corn growing season would be of value to cover the cost of control （spray） but do not achieve similar economic value of revenue comparing with the resistant genotype.
