A Scheme on the Integration of VPN and PKI

A Scheme is introduced in this paper on integration of VPN and PKI. Techniques concerning authentication and data package in VPN, and cross-certification in PKI are described. With the employment of PKI and CA, the network security and key management in VPN are improved. The integration is transparent to the users and cost-effective in setting up and maintaining a VPN.     

Implementation and control of asymmetric thermal environment in two-dimensional rectangular enclosure

Laminar natural convection in an enclosure divided by an adiabatic partition on its bottom with two unequal discrete heat sources was investigated numerically. The effect of the partition on the flow structure and heat transfer characteristics in enclosure under asymmetric heating condition was studied. The parameters are the Rayleigh number (1 × 104 ≤Ra≤1 × 106) and the height of partition (0≤h/H≤0. 70). The streamlines are produced for various Rayleigh numbers. The results reflected by variations of the average Nusselt number in terms of the height of partition illustrates the convection heat transfer in the enclosure. The role of the partition is to weaken or cut off the heat removal rate from the strong heat source to the weak heat source. It is analyzed that the optimum height of the partition to break the linkage between the strong and weak heat source increases with increasing Rayleigh number.     

MINING INDUCED INFLUENCE ON THE ROADWAYS IN WEAK SURROUNDING ROCK AND ITS CONTROLLING MEASURES

The application of destressing method can change the distribution patterns of the stress field in the weak rock surrounding openings, locate the openings in the zone of low stress level, thus improve their loading and maintaining conditions. Such method is considered as a new way of opening maintenance in weak rock and has caused extensive interests in mining industry both at home and abroad. The results of theoretic research and lab experiments of utilizing topdestresslng trough to maintain the opening affected by mining activities in weak rock, as well as its practical application in a coal mine are introduced in this paper. The research results indicate that the deformation and floor heaving of the opening in weak rock can be effectively controlled, and long-term stability of the opening can be realized by applying destressing method as long as the destressing plan and concerned parameters are carefully determined.     

Multi-slots Wideband Cooperative Spectrum Sensing Based on Weighed Data Fusion in Cognitive Radio

In order to avoid the interference to the primary user(PU), in this paper Cognitive Radio (CR) periodically senses the presence of PU, and during one period, CR can sense all the sub-channels based on weighed data fusion and then use all the idle channels decided by the coordinator. The local sensing time of CR is divided into multi-slots in which CR can sense any sub-channel. Through reasonably allocating the sensing slots and users by mathematic optimization, the proposed algorithm can improve the total throughput of CR. The optimization problem of the proposed scheme which seeks to maximize the throughput subject to the constraint of the detected performance of each sub-channel is proposed in order to choose the optimum local sense time and the number of the cooperative CRs. The simulation results indicate that the proposed scheme can obtain higher throughput than the conventional single-channel sense, and there are the optimum local sense time and the number of cooperative CRs to make the throughput reach maximum.     

An improved Mesri creep model for unsaturated weak intercalated soils

The weak intercalated soils in redbed soft rocks of Badong formation have obvious creep characters. In order to predict the unsaturated creep behaviors of weak intercalated soils, an unsaturated creep model was established based on the unsaturated creep tests of weak intercalated soils by using GDS triaxial apparatus. The results show that the creep behaviors of intercalated soils are apparent and significantly affected by matric suction. Based on this, an empirical Mesri creep model for intercalated soils under varying matric suctions was built. The fitting results show that the parameters Ed and m of this model are in good power relations with matric suction s and stress level Dr, respectively. An improved Mesri creep model was established involving stress-matric suction-strain-time, which is more precise than the Mesri creep model in predicting the unsaturated creep behaviors of weak intercalated soils.     

Diagenetic evolution and its effect on reservoir-quality of fan delta sandstones during progressive burial: Evidence from the upper part of the fourth member of Shahejie formation,Bonan sag,Jiyang depression

Petrographic analysis combined with various techniques, such as thin section identification, fluid inclusions, isotopic data, petro-physical property testing and oil testing results, was used to study diagenetic evolution and its effect on reservoir-quality of fan delta reservoirs of Es4s in the Bonan sag. The diagenesis is principally characterized by strong compaction, undercompaction, multi-phase of dissolution and cementation. Compaction played a more important role than cementation in destroying the primary porosity of the sandstones. The reservoirs have experienced complicated diagenetic environment evolution of "weak alkalineacid-alkalinity-acid-weak alkalinity" and two-stage of hydrocarbon filling. The diagenetic sequences are summarized as "early compaction/early pyrite/gypsum/calcite/dolomite cementation→feldspar dissolution/the first stage of quartz overgrowth → early hydrocarbon filling→quartz dissolution/anhydrite/Fe-carbonate cementation→Fe-carbonate dissolution/feldspar dissolution/ the second stage of quartz overgrowth→later hydrocarbon filling→later pyrite cementation. In the same diagenetic context, the diagenetic evolution processes that occurred in different sub/micro-facies during progressive burial have resulted in heterogeneous reservoir properties and oiliness. The braided channel reservoirs in fan delta plain are poorly sorted with high matrix contents. The physical properties decrease continually due to the principally strong compaction and weak dissolution. The present properties of braided channel reservoirs are extremely poor, which is evidenced by few oil layers developed in relatively shallow strata while dry layers entirely in deep. The reservoirs both in the underwater distributary channels and mouth bars are well sorted and have a strong ability to resist compaction. Abundant pores are developed in medium-deep strata because of modifications by two-stage of acidic dissolution and hydrocarbon filling. The present properties are relatively well both in the underwater distributary channels and mouth bars and plenty of oil layers are developed in different burial depth. The present reservoir properties both in interdistributary channel and pre-fan delta are poor caused by extensively cementation. Small amounts of oil layers, oil-water layers and oil-bearing layers are developed in relatively shallow strata while dry layers totally in deep.     

Complete characterization of strictly positive real regions and robust strictly positive real synthesis method

The concept of weak strictly positive real regions is introduced, and its properties are discussed . By using the complete discrimination system for polynomials, complete characterization of the (weak) strictly positive real regions for transfer functions in coefficient space is given. A new effective method for robust strictly positive real synthesis is proposed. This method results in necessary and sufficient conditions for low-order stable interval polynomials and segment polynomials, and is also efficient for high-order cases. Numerical examples are provided to illustrate the effectiveness of this method.     

Mathematical modelling on instability of shear fault

A study on mathematical modelling on instability of fault is reported.The fracture mechanics and fracture dynamics as a basis of the discussion,and the method of complex variable function (including the conformal mapping and approximate conformal mapping) are employed,and some analytic solutions of the problem in closed form are found.The fault body concept is emphasized and the characteristic size of fault body is introduced.The effect of finite size of the fault body and the effect of the fault propagating speed (especially the effect of the high speed) and their influence on the fault instability are discussed.These results further explain the low-stress drop phenomena observed in earthquake source.     

Symbolic transition graph and its early bisimulation checking algorithms for the π-calculus

Symbolic transition graph is proposed as an intuitive and compact semantic model for the π-calculus processes.Various versions (strong/weak, ground/symbolic) of early operational semantics are given to such graphs. Based on them the corresponding versions of early bisimulation equivalences and observation congruence are defined. The notions of symbolic observation graph and symbolic congruence graph are also introduced, and followed by two theorems ensuring the elimination of τ-cycles and τ-edges. Finally algorithms for checking strong/weak early bisimulation equivalences and observation congruence are presented together with their correctness proofs. These results fuse and generalize the strong bisimulation checking algorithm for value-passing processes and the verification technique for weak bisimulation of pure-CCS to the finite control π-calculus.     

集值向量变分不等式组的数量化方法

文章定义了四种集值变分不等式组,即分别具有强解和弱解的集值向量变分不等式组和集值数量化变分不等式组。通过运用Konnov的数量化方法,研究将一个集值向量变分不等式组转化为一个集值数量化变分不等式组,并给出了两种集值变分不等式组的等价条件。     

两相问题的一个数学模型

本文从两相共存的介面变化抽象为集值映射.仿矢值映射的求导,引入了集值映射求导的概念及可导条件.接着,仿微分几何的曲线论,建立了基本公式和唯一存在定理.最后,以实例说明导数集的物理意义.     

Benson真有效意义下集值映射的广义共轭对偶理论

引入Ｂｅｎｓｏｎ真有效意义下的集值映射的共轭映射及Ｂｅｎｓｏｎ真有效次梯度,建立了Ｂｅｎｓｏｎ真有意义下的共顾对偶理论,证明了强、弱对偶定理和鞍点定理。     

关于集值局部连通映射的连通性和连续性

把单值映射局连通性的概念推广到集值映射上，并且给出了集值局部连通映射是连通映射和连续映射的条件。     

集值映射的一致有界定理

建立了一类集值映射的一致有界定理，进而讨论了这类集值映射的连续性与有界性之间的联系，使得单值映射的相应结果作为本文的一种特例。     

几乎连通集值映射的连通性与连续性

给出了几乎连通信值映射的概念，并组给出了几乎连通集值映射成为连通映射及连续映射的条件。     

集值映射最优化问题的弱有效解

给出反例说明Jahn和Rauh提出的关于集值优化问题的弱有效解结论的错误,并对其条件进行了改进,得到了集值映射最优化问题的弱有效解的最优性条件.     

关于连续集值映射的一个逼近性质

得到从度量空间到Ｂａｎａｃｈ空间的紧凸值集值映射，均可通过有限秩连续集值映射任意逼近。     

Banach空间中的一类广义混合非线性隐拟变分包含

给出了Banach空间中一类广义集值混合非线性隐拟变分包含问题，通过对m-增生映象运用Nadler定理和隐预解算子技巧，构建了这类广义变分包含的迭代算法，并证明了其解的存在性和由迭代算法生成的迭代序列的收敛性。     

关于可测集值映射的Egorov定理

本文讨论了取值于可分自反Ｂａｎａｃｈ空间可测集值映射序列的Ｅｇｏｒｏｖ型收敛定理，在几种不同拓扑收敛意义下，刻划了可测集值映射序列的几科处处收敛。