实时OD估计中卡尔曼滤波算法研究

ITS研究中，动态OD矩阵估计是交通动态分配的关键因素。针对OD矩阵难以获得的问题，回顾动态OD矩阵估计理论的发展历程，明确该领域研究中的三个关键问题：状态变量的选择、系统方程的确定、OD量与路段流量的关系（分配矩阵）。在此基础上介绍一种基于历史OD矩阵数据的估计方法，卡尔曼滤波算法，为动态OD矩阵估计理论的进一步的研究奠定基础。     

企业剩余分享及其产权机理

企业剩余由资本所有者独享向其他要素所有者共同分享的演进是现代企业治理结构发展的一个重要趋势。本文对剩余和剩余分享进行了界定,分析了剩余分享的几种情形,阐释了剩余分享的内在产权机理及其主要途径。     

中国国有银行的资本金谜团

本文旨在考察中国国有银行资本金谜团的由来 ,并为破解该谜团提供一种可能的视角。本文的讨论表明 ,国有银行之所以能在真实资本极少得到补充且不良贷款比率居高不下的情况下保持稳定 ,是因为国家与居民在中国特殊的改革背景下建立起了一种奇妙的资本联盟。由于在这种联盟中 ,国家以声誉入股且具有不可分性 ,因此 ,中国国有银行改革的可行方式是谋求改变资产结构 ,而不是试图重组资本结构。     

商业银行操作风险管理体系建设研究

操作风险管理在我国尚处于起步阶段,各商业银行将于2010年底全面实施《新巴塞尔协议》对于风险管理的规定。本文针对我国商业银行的现状及未来发展,从实践的角度,对操作风险管理体系的主要框架、所含内容以及操作方法等问题进行了讨论。     

On new variance approximations for linear models with inequality constraints

In this paper, we examine the estimation of linear models subject to inequality constraints with a special focus on new variance approximations for the estimated parameters. For models with one inequality restriction, the proposed variance formulas are exact. The variance approximations proposed in this paper can be used in regression analysis, Kalman filtering, and balancing national accounts, when inequality constraints are to be incorporated in the estimation procedure.     

A Partially Observed Model for Micromovement of Asset Prices with Bayes Estimation via Filtering

A general micromovement model that describes transactional price behavior is proposed. The model ties the sample characteristics of micromovement and macromovement in a consistent manner. An important feature of the model is that it can be transformed to a filtering problem with counting process observations. Consequently, the complete information of price and trading time is captured and then utilized in Bayes estimation via filtering for the parameters. The filtering equations are derived. A theorem on the convergence of conditional expectation of the model is proved. A consistent recursive algorithm is constructed via the Markov chain approximation method to compute the approximate posterior and then the Bayes estimates. A simplified model and its recursive algorithm are presented in detail. Simulations show that the computed Bayes estimates converge to their true values. The algorithm is applied to one month of intraday transaction prices for Microsoft and the Bayes estimates are obtained.     

Covariance formulas via marginal martingw

Prenctice and Cai recently introduced and studied the function C defined as the covariance function of the two marginal counting process martingales of a pair of dependent survival times (T₁, T₂ ). They show that the function C together with the marginal distributions determines the joint survival function F of (T₁, T₂ ). In this note we show how the key characterizing equation of Prentice and Cai yields a formula for the covariance of T₁ and T₂ in termsof the marginal mean residual life functions and C. The resulting formula generalizes a formula for the variance of a one-dimensional random variable Tdueto Pyke (1965). We also explore several generalizations of the covariance formula, and obtain a valid k-dimensional version of the Prentice and Cai formula.     

Debreu’s coefficient of resource utilization, the Solow residual, and TFP: the connection by Leontief preferences

Debreu’s coefficient of resource utilization is freed from individual data requirements. The procedure is shown to be equivalent to the imposition of Leontief preferences. The rate of growth of the modified Debreu coefficient and the Solow residual are shown to add up to TFP growth. This decomposition is the neoclassical counterpart to the frontier analytic decomposition of productivity growth into technical change and efficiency change. The terms can now be broken down by sector as well as by factor input.

Efficient learning via simulation: A marginalized resample-move approach

In state–space models, parameter learning is practically difficult and is still an open issue. This paper proposes an efficient simulation-based parameter learning method. First, the approach breaks up the interdependence of the hidden states and the static parameters by marginalizing out the states using a particle filter. Second, it applies a Bayesian resample-move approach to this marginalized system. The methodology is generic and needs little design effort. Different from batch estimation methods, it provides posterior quantities necessary for full sequential inference and recursive model monitoring. The algorithm is implemented both on simulated data in a linear Gaussian model for illustration and comparison and on real data in a Lévy jump stochastic volatility model and a structural credit risk model.     

生物聚合物改良玄武岩残积土崩解特性研究

为提高玄武岩残积土的抗崩解性及其边坡水稳性,利用生物聚合物瓜尔胶改良玄武岩残积土。在干湿循环条件下开展不同掺量瓜尔胶改良玄武岩残积土的崩解试验,观察残积土崩解过程,并对残积土改良土崩解系数和平均崩解速率进行测定,分析瓜尔胶掺量及干湿循环次数对玄武岩残积土水稳性的影响。研究结果表明：瓜尔胶可有效增强玄武岩残积土的抗崩解性能,随着瓜尔胶掺量的增加,改良玄武岩残积土的崩解系数和平均崩解速率呈现先减小后增加的特点,在瓜尔胶掺量为1.0%时抗崩解性能最佳;瓜尔胶掺量一定时,改良玄武岩残积土的崩解系数和平均崩解速率随着干湿循环次数的增加呈现增长趋势,当干湿循环次数N=4时,土体崩解率为N=1时的8倍。由此可见,瓜尔胶作为一种新型、环保的残积土边坡防护材料,可有效提升玄武岩残积土的抗崩解性能。研究结果为生态环保处置玄武岩残积土提供了新的思路,可为玄武岩残积土地区边坡工程的绿色发展提供参考。