Searching for a set of correlated patterns

New algorithms for searching simultaneously for a set of patterns in a text are suggested, for the special case where these patterns are correlated and have a common substring. This is then extended to the case where it could be more profitable to look for more than a single overlap, and a problem related to the generalization of this idea is shown to be NP-complete. Experimental results suggest that for this particular application, the suggested algorithm yields significant improvements over previous methods.     

The inverse balayage problem for Markov chains

Let X be a Markov chain, let A be a finite sunset of its countable state space. let ?A consist of states in A′ that can be reached in one step from A and let v be a prescribed probability measure on ?A. In this paper we study the following inverse exit problem: describe and analyze the set M(v) of probability measures μ on A such that P^μ {X(T)?·}=v(·) where T= inl{k: X(k)?A′} is the first exit time from A. Characterizations are provided for elements of M(v), extreme points of M(v) and those measures in M(v) that are maximal with respect to a partial ordering induced by excessive functions. Potential theoretic aspects of the problem and one-dimensional birth and death processes are treated in detail, and examples are given that illustrate implications and limitations of the theory.     

Integration by parts formulas and dilatation vector fields on elliptic probability spaces

Summary. By coupling two arbitrary riemannian connections Γ and Γ˜ on a riemannian manifold M, we perform the stochastic calculus of ɛ-variation on the path space P(M) of the manifold M. The method uses direct calculations on Ito’s stochastic differential equations. In this context, we obtain intertwinning formulas with the Ito map for first order operators on the path space P(M) of M. By a judicious choice of the second connection Γ˜ in terms of the connection Γ, we can prolongate the intertwinning formulas to second order differential operators. Thus, we obtain expressions of heat operators on the path space P(M) of a riemannian manifold M endowed with an arbitrary connection. The integration by parts of the laplacians on P(M) leads us to the notion of dilatation vector field on the path space. Received: 18 April 1995 / In revised form: 18 March 1996     

Sufficiently general framework for simple models of the net immune response

A general framework for modelling the immune response is proposed and analyzed. The models have simple formulation in terms of only few measurable quantities and the complexity of the immune response is accounted for by using nonlinear functions with time-delayed arguments. It is illustrated that such models are capable of describing various typical cases of the immune response. Standard analytical tools are used to show how such models can assist in the problem of parameter estimation.     

有缺失数据的2×2×2列联表的参数估计

本文讨论了缺失数据的 2× 2× 2列联表的参数估计问题 ,通过给出适当的模型和观测数据模式 ,我们给出了各列联表各细胞参数的估计 ,并且证明这些估计是G -Markov的     

住院病人构成动态分析与预测

本文对某一综合性教学医院１９８２～１９９１年住院病人进行疾病顺位动态分析与预测．结果表明：①肿瘤、消化、呼吸系统疾病顺位居高不下；②传染病、神经系统和感觉器官疾病顺位逐年下降；③循环、泌尿生殖系统疾病顺位有上升趋势　对疾病变化因素和统计预测进行了讨论．     

Classification of secondary ion mass spectrometry (SIMS) micrographs to characterize chemical phases

This work demonstrates the potential of multivariate image analysis methods in the extraction of useful, problem dependent information from SIMS images. Specific algorithms have been developed to classify SIMS micrographs manually as well as automatically. A feature selection has been achieved by means of principal component analysis with a subsequent image classification.As an application example for these improved digital image processing tools chemical phases within a soldered industrial metal sample have been identified. This is of highly practical value as it was assumed that during the soldering process inhomogeneities occur along the joint site which cause a cracking of the brazed material under mechanical strain conditions.     

Spatio-temporal patterns in the thermoconvection of a planar nematic layer: II. Experiments

We study experimentally the evolution of thermoconvection in a laterally extended planar nematic layer, at zero or weak stabilizing magnetic field. As the applied thermal gradient is increased, a cascade of symmetry breakings occurs, towards structures of increasing spatial complexity, and ultimately towards oscillating states. The patterns are characterized optically, and simple models for the distortion of the vertical (out of plane) component of the director field are proposed. Received: 1st December 1997 / Revised: 25 May 1998 / Accepted: 2 June 1998