逆向选择条件下委托代理最优激励契约模型分析

分别建立了逆向选择条件下离散类型和连续类型的最优激励契约模型,并利用最优化控制原理求出了模型的最优解.为保险委托人设计合理的激励契约提供了理论参考依据.     

基于经济增加值法的风险投资分段投资博弈模型

运用委托代理理论和激励理论,建立了存在道德风险的风险投资家和风险企业家的分段投资激励博弈模型.在模型中用经济增加值指标代替了传统的会计指标,给出了风险投资家与风险企业家的期望收益函数,得出了最优激励报酬契约应满足的条件,为风险投资家设计最优激励报酬方案和改善投资决策提供了理论依据.     

企业网络组织稳定性的激励模型分析

针对企业网络组织不稳定的问题,建立了单委托人-多代理人的激励模型,基于企业收益率可测性情况分别进行讨论.在求解的基础上对激励契约的效果进行比较分析,得出有关最优固定报酬和激励系数之间关系的一系列结论,提出了构造激励契约的建议.     

非对称信息下供应链中商业信用激励契约研究

利用委托代理分析框架研究供应链中制造商向零售商提供商业信用的激励作用.通过比较信息对称和非对称信息两种条件下信用激励契约的设计,分析了供应链中制造商与零售商之间的利益博弈,确定了使委托人期望效用最大的契约参数.指出零售商在非对称信息条件下付出的最优努力水平小于信息对称条件下的最优努力水平,随着零售商风险厌恶程度的增大,商业信用的激励作用会减弱.最后,给出了一个算例.     

基于声誉机制的开放式基金家族激励效率优化

首先,建立动态委托代理模型,研究业绩激励机制产生效率损失的原因和影响因素.进而,从基金家族视角建立声誉机制,优化开放式基金的激励效率.结果表明,业绩激励机制产生的效率损失,随证券市场中信息透明度的降低而增大,随投资期限的增加而降低;基金家族建立的声誉机制,能在基金经理之间产生一种正面的声誉传递作用,从而提高了开放式基金的激励效率,并在一定条件下,使其达到帕累托最优.最后,结合现实分析了所建模型的应用价值.     

信任、经理人激励与家族企业治理

信任治理是解决"家族主义困境"的重要方式.它通过使家族提供的包含信任信息的工作条件符合经理人预期的形式来激励经理人.家族根据对经理人的信任水平来调整相应的激励机制.不同的激励机制反映为不同的家族企业治理模式.来自对沪市家族上市企业的实证研究表明:采用要素使用权契约激励机制的治理模式是最有效率的.在相似的要素使用权契约水平下,家族控制要比家族大规模放权要更有效率,这说明我国家族企业的信任治理还不成熟.     

需求依赖价格且模糊的供应链回购契约

在需求依赖价格且模糊的假设下,研究了由一个供应商和一个零售商组成的供应链回购契约协调机制.首先,运用可信性理论,建立了分散决策下的Stackelberg博弈模型,给出了模型最优解的求解过程.其次,研究了一体化决策问题,得到了系统最优解,并通过比较说明分散决策不能实现供应链系统的最优化;再次,建立了基于回购契约的供应链协调模型,分析了回购机制下的最优解与集中决策最优解的关系;最后,给出了供应链能够实现完美协调的充分条件.     

知识员工经济契约的优化:基于公平与互惠理论

在知识经济社会里,作为知识载体的知识员工逐步取代了传统的劳动力而成为各类组织中的核心员工,因而对知识员工的激励机制的研究是人力资源管理中的重要课题,而由于知识员工的特性,基于"理性人"假设的经济契约不能进行有效的激励。公平与互惠理论对传统的"经济人"假设提出了挑战,考虑了知识员工表现在"互惠性"非理性行为的基础上建立起的新的经济契约,结果显示,新的经济契约的最优合约可以给组织带来比传统经济契约的最优合约更高的利润水平。     

隐蔽信息条件下两级供应链系统1:n协调激励模型

主要研究供应商在不能确定零售商类型的条件下,如何对零售商进行有效的协调激励,以实现供应商最大化利益.首先从特殊的情况出发,即假设存在两种类型零售商、三种类型零售商,分别建立协调激励模型,在此基础上,提出供应商面对n,种类型零售商时,供应商最优协调激励模型.     

基于委托-代理理论的口碑推荐激励机制研究

产品或服务的口碑推荐过程中,企业和口碑推荐者之间形成委托-代理激励契约关系.在信息对称情况下,企业和口碑推荐者可以达成"承包"方式的激励契约:只要推荐者成功推荐规定数量的接受者(顾客),即可获得企业提供的最优固定激励.在非对称信息情况下,企业和口碑推荐者可以达成"线性"方式的激励契约:只要口碑推荐者付出一定水平的努力投入(最优努力投入),即可获得企业提供的最优激励支付,并且实现契约利润效用的最大化.     

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.     

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…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

<正>~~     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

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