This paper discusses the degree of completeness of cryptographic functions, which is one of the cryptographic criteria should be considered in the design of stream ciphers. We establish the relationships between the d...This paper discusses the degree of completeness of cryptographic functions, which is one of the cryptographic criteria should be considered in the design of stream ciphers. We establish the relationships between the degree of completeness and other cryptographic criteria. For resilient Boolean functions, a method to enhance the degree of completeness is proposed, while the nonlinearity and the algebraic degree do not decrease. Moreover, two constructions of resilient functions are provided, which have optimal degree of completeness, high nonlinearity, and high algebraic degree.展开更多
Due to the limitation of actual shale gas reservoir conditions and fracturing technologies,artificial fracture networks are different greatly even in the same or similar stimulated reservoir volume.Deviations and even...Due to the limitation of actual shale gas reservoir conditions and fracturing technologies,artificial fracture networks are different greatly even in the same or similar stimulated reservoir volume.Deviations and even faults occur in evaluation and cognition if only the stimulated reservoir volume(SRV)is used to characterize and evaluate the effect of stimulation.In this paper,the spatial distribution of artificial fractures and natural fractures and the internal pressure state and degree of reserve recovery of stimulated shale gas reservoirs were studied by means of artificial fracture propagation numerical simulation and production numerical simulation.And three concepts were proposed,i.e.,shale gas fracture network,ideal fracture network and appropriate-stimulation degree of fracture network.The study results indicate that,at the end of reservoir development,target zones can be classified into three types(i.e.,relatively appropriate stimulation zone,transitional stimulation zone,and uncompleted stimulation zone)according to the recovery degree and production time of stimulated reservoirs;and that the final morphologic parameter of fracture networks and the reservoir characteristic are two main factors affecting the appropriate-stimulation degree of fracture networks.As for a specific gas reservoir,the orientation,length,conduction,height and spatial location of its fracture network are the main factors influencing its appropriate-stimulation degree if the well trajectory is set.The proposal of the theory on the appropriate-stimulation degree of hydraulic fracture networks in shale gas reservoir enriches the theoretical system of shale reservoir stimulation technology,and it can be used as the reference for characterizing the fracture systems in other unconventional reservoirs,such as tight oil and gas reservoirs.展开更多
In this paper,we study the completely monotonic property of two functions involving the functionΔ(x)=[ψ′(x)]2+ψ″(x)and deduce the double inequality x^(2)+3x+3/3x^(4)(2x+1)^(2)<Δ(x)<625x^(2)+2275x+5043/3x^(...In this paper,we study the completely monotonic property of two functions involving the functionΔ(x)=[ψ′(x)]2+ψ″(x)and deduce the double inequality x^(2)+3x+3/3x^(4)(2x+1)^(2)<Δ(x)<625x^(2)+2275x+5043/3x^(4)(50x+41)^(2),x>0which improve some recent results,whereψ(x)is the logarithmic derivative of the Gamma function.Also,we deduce the completely monotonic degree of a function involvingψ′(x).展开更多
Let G be a maximal outerplane graph and X0(G) the complete chromatic number of G. This paper determines exactly X0(G) for △(G)≠5 and proves 6≤X0.(G)≤7 for △(G) = 5, where △(G) is the maximum degree of vertices o...Let G be a maximal outerplane graph and X0(G) the complete chromatic number of G. This paper determines exactly X0(G) for △(G)≠5 and proves 6≤X0.(G)≤7 for △(G) = 5, where △(G) is the maximum degree of vertices of G.展开更多
基金Supported by the National Key Basic Research Program of China(No.2013CB834204)
文摘This paper discusses the degree of completeness of cryptographic functions, which is one of the cryptographic criteria should be considered in the design of stream ciphers. We establish the relationships between the degree of completeness and other cryptographic criteria. For resilient Boolean functions, a method to enhance the degree of completeness is proposed, while the nonlinearity and the algebraic degree do not decrease. Moreover, two constructions of resilient functions are provided, which have optimal degree of completeness, high nonlinearity, and high algebraic degree.
文摘Due to the limitation of actual shale gas reservoir conditions and fracturing technologies,artificial fracture networks are different greatly even in the same or similar stimulated reservoir volume.Deviations and even faults occur in evaluation and cognition if only the stimulated reservoir volume(SRV)is used to characterize and evaluate the effect of stimulation.In this paper,the spatial distribution of artificial fractures and natural fractures and the internal pressure state and degree of reserve recovery of stimulated shale gas reservoirs were studied by means of artificial fracture propagation numerical simulation and production numerical simulation.And three concepts were proposed,i.e.,shale gas fracture network,ideal fracture network and appropriate-stimulation degree of fracture network.The study results indicate that,at the end of reservoir development,target zones can be classified into three types(i.e.,relatively appropriate stimulation zone,transitional stimulation zone,and uncompleted stimulation zone)according to the recovery degree and production time of stimulated reservoirs;and that the final morphologic parameter of fracture networks and the reservoir characteristic are two main factors affecting the appropriate-stimulation degree of fracture networks.As for a specific gas reservoir,the orientation,length,conduction,height and spatial location of its fracture network are the main factors influencing its appropriate-stimulation degree if the well trajectory is set.The proposal of the theory on the appropriate-stimulation degree of hydraulic fracture networks in shale gas reservoir enriches the theoretical system of shale reservoir stimulation technology,and it can be used as the reference for characterizing the fracture systems in other unconventional reservoirs,such as tight oil and gas reservoirs.
文摘In this paper,we study the completely monotonic property of two functions involving the functionΔ(x)=[ψ′(x)]2+ψ″(x)and deduce the double inequality x^(2)+3x+3/3x^(4)(2x+1)^(2)<Δ(x)<625x^(2)+2275x+5043/3x^(4)(50x+41)^(2),x>0which improve some recent results,whereψ(x)is the logarithmic derivative of the Gamma function.Also,we deduce the completely monotonic degree of a function involvingψ′(x).
基金Project supported by the Vatural SCience Foundation of LNEC.
文摘Let G be a maximal outerplane graph and X0(G) the complete chromatic number of G. This paper determines exactly X0(G) for △(G)≠5 and proves 6≤X0.(G)≤7 for △(G) = 5, where △(G) is the maximum degree of vertices of G.
