The problem of perfectly secure communication has enjoyed considerable theoretical treatment over the last decades. Results in this area include the identification of multipath transmission as a necessary ingredient, ...The problem of perfectly secure communication has enjoyed considerable theoretical treatment over the last decades. Results in this area include the identification of multipath transmission as a necessary ingredient, as well as quantum key distribution （QKD）, which can perfectly protect direct lines, Combining the advantages of the quantum and multipath transmission paradigm, as well as rigorously analyzing the security of such combined techniques, is possible by virtue of game-theory. Based on a game-theoretic measure of channel vulnerability, the authors prove the problem of setting up infrastructures for QKD-based multipath transmission to be NP-complete. The authors consider the problem in two flavors, both being computationally hard. Remarkably, the authors＇ results indicate that the P-vs-NP-question is only of minor effect for confidentiality, because either nowadays public-key cryptosystems remain secure （in case that P, NP） or infrastructures facilitating perfectly confidential communication can be constructed efficiently （in case that P = NP）.展开更多
Under the target of the sustainable development,optimization of forestry industrial structure contains rationalization and advancement of forestry industrial structure in the traditional sense,as well as ecologicaliza...Under the target of the sustainable development,optimization of forestry industrial structure contains rationalization and advancement of forestry industrial structure in the traditional sense,as well as ecologicalization of forestry industrial structure.The connotation of optimization of forestry industrial structure is analyzed at first,and then the paper chooses the typical evaluation indexes from the three sides of rationalization,advancement and ecologicalization to evaluate the current situation of the regional forestry industrial structure.With the aid of the theory of fuzzy mathematics and information entropy,the paper establishes a fuzzy evaluation model which is based on information entropy for optimization of forestry industrial structure,and the evaluation model is applied in the study for the current situation of forestry industrial structure from 2000 to 2006 in Hubei province.The results show that the grade of forestry industrial structure is bad basically during the research,of which the overall level of forestry industrial structure of Hubei province is poor,the degree of utilizing forest resource is lower,and ecological environment in the forest region has been damaged to some extent.On this basis,the author presents the countermeasure to promote the optimization of forestry industrial structure.展开更多
文摘The problem of perfectly secure communication has enjoyed considerable theoretical treatment over the last decades. Results in this area include the identification of multipath transmission as a necessary ingredient, as well as quantum key distribution （QKD）, which can perfectly protect direct lines, Combining the advantages of the quantum and multipath transmission paradigm, as well as rigorously analyzing the security of such combined techniques, is possible by virtue of game-theory. Based on a game-theoretic measure of channel vulnerability, the authors prove the problem of setting up infrastructures for QKD-based multipath transmission to be NP-complete. The authors consider the problem in two flavors, both being computationally hard. Remarkably, the authors＇ results indicate that the P-vs-NP-question is only of minor effect for confidentiality, because either nowadays public-key cryptosystems remain secure （in case that P, NP） or infrastructures facilitating perfectly confidential communication can be constructed efficiently （in case that P = NP）.
基金supported by National Social Sciences Fund of China (Grant No 09XSH018)
文摘Under the target of the sustainable development,optimization of forestry industrial structure contains rationalization and advancement of forestry industrial structure in the traditional sense,as well as ecologicalization of forestry industrial structure.The connotation of optimization of forestry industrial structure is analyzed at first,and then the paper chooses the typical evaluation indexes from the three sides of rationalization,advancement and ecologicalization to evaluate the current situation of the regional forestry industrial structure.With the aid of the theory of fuzzy mathematics and information entropy,the paper establishes a fuzzy evaluation model which is based on information entropy for optimization of forestry industrial structure,and the evaluation model is applied in the study for the current situation of forestry industrial structure from 2000 to 2006 in Hubei province.The results show that the grade of forestry industrial structure is bad basically during the research,of which the overall level of forestry industrial structure of Hubei province is poor,the degree of utilizing forest resource is lower,and ecological environment in the forest region has been damaged to some extent.On this basis,the author presents the countermeasure to promote the optimization of forestry industrial structure.
