多险种的Cox风险模型

经典风险模型描述的险种是单一的，并且假设保费收入是线性增长的。事实上保险公司的经营是多元化的。为此，将经典风险模型进行了推广，建立了理赔次数服从Cox过程的多险种的风险模型，并运用鞅方法得到了破产概率的上界，进一步考虑到理赔次数对保费收入的影响，得到了其改进模型及其结果。     

一类多险种风险模型

本文将经典的风险模型推广为多险种风险模型；应用鞅方法；得到最终破产概率和Lundberg不等式．     

常数投资风险资产策略下保险公司的破产概率

研究了保险公司的无限时间破产概率,在Cramér-Lundberg经典风险模型的基础上,考虑了公司将其一部分盈余资产投资到风险市场,风险资产价值满足几何布朗运动过程;盈余资产的另一部分投资于常数利息力为i无风险资产中.在常数投资风险资产策略下,得到了和经典模型下相似的破产概率的上界估计和调节系数,并且其上界均为指数型上界.调节系数比Lundberg系数大,即破产概率的上界比经典风险模型要小.     

随机利率下双复合Poisson风险模型的破产概率

考虑随机利率因素下,将经典风险模型推广到保费收入和索赔支出相互独立的双复合Poisson风险模型,得到该风险模型的最终破产概率的精确表达式和一般不等式.     

一类多险种风险模型

本文将经典的风险模型推广为多险种风险模型;应用鞅方法;得到最终破产概率和Lundberg不等式.     

带干扰的双险种Poisson风险模型的破产概率

经典风险模型描述了单一险种的经营模式,本文将其推广为带干扰的双险种Poisson风险模型,应用鞅论的方法得到了其最终破产概率的Lundberg不等式及一般表达式.     

保费再投资下双Cox风险模型的破产概率

基于经典的风险模型,考虑了对于保费进行稳健投资的情况,引入了将保费进行再投资情况下的双Cox风险模型,利用鞅方法研究了破产概率问题,得到了该模型的破产概率的Lundberg不等式,并对Lundberg不等式进行了推广。     

复合Poisson-Geometric过程风险模型推广

针对经典风险模型中Poisson过程均值必须等于方差这一局限,将其推广到复合Poisson-Geometric过程,并将保费收取次数看作是一个Poisson过程,且每次收到的保费看作是一个随机变量且服从指数分布,得到了对古典风险模型的一个推广.解释了做出这种推广的实际意义,经过推算,得到了调节系数以及破产概率的表达式,进而得到了模型对应的Lundeberg不等式.     

双Cox风险模型中破产概率的上界

将经典风险模型推广为带干扰的双Cox风险模型,使该模型更符合现实情况,然后利用鞅论的知识对其进行研究,得到了该模型的破产概率的Lundberg指数上界,并讨论了当c=0时,该模型的非Lundberg指数上界.     

带投资组合和超额赔款的再保险双Cox风险模型

对于保单到达过程与索赔过程均为 Cox 过程的情况,考虑到保险公司为了规避风险进行投资组合和再保险,将经典风险模型推广,建立了一类再保险双 Cox 风险模型,运用鞅论方法得到了此模型 Lund-berg 指数上界和破产概率的上界,并给出了最终破产概率的解析表达式。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.