A new perspective for discrete-time models of a continuous-timesystem

Various discrete-time models of a continuous-time system are given an interpretation in terms of the system structures and the hold device. This concept provides a novel perspective of various discrete-time models and a simple way to understand the relationships which exist among those models, but which are not easily visualized without the proposed interpretation. This interpretation of discrete-time models also allows the creation of new types of models. Tables of discrete-time models, including the newly developed ones, are provided     

On-line algorithms for polynomially solvable satisfiability problems

Given a propositional Horn formula, we show how to maintain on-line information about its satisfiability during the insertion of new clauses. A data structure is presented which answers each satisfiability question in O(1) time and inserts a new clause of length q in O(q) amortized time. This significantly outperforms previously known solutions of the same problem. This result is extended also to a particular class of non-Horn formulae already considered in the literature, for which the space bound is improved. Other operations are considered, such as testing whether a given hypothesis is consistent with a satisfying interpretation of the given formula and determining a truth assignment which satisfies a given formula. The on-line time and space complexity of these operations is also analyzed.     

A TEXT THEORY OF ECOLOGICAL SYSTEM

In this paper, the authors continue with the development of an ecological models theory from the viewpoint of mathematical linguistics. The model is considered as a text, which complies with the text theory TT conditions. The variable transformed functions are defined as symbols, the flow equations are defined as words, the flow functions or right hand of differential equations are defined as sentences, resting on the author particular methodology inspired inspired in the system dynamic illustrated in other papers. Three meaning levels are established in each model text and the duality significance or explanation adjustment and significance or interpretation for the observer is defined as getting in the indexes for its indirect measure. A model interpretation theory is given also.     

Constructive Sets in Computable Sets

The original interpretation of the constructive set theory CZF in Martin-Loef‘s type theory uses the‘extensional identity types’.It is generally believed that these‘types’do not belong to type theory.In this paper it will be shown that the interpretation goes through without identity types.This paper will also show that the interpretation can be given in an intensional type theory.This reflects the computational nature of the interpretation.This computational aspect is reinforced by an ω-Set moel of CZF.     

Model-structure selection by cross-validation

Two criteria for choosing between different model-structures are proposed. Their derivation is within a natural cross-validatory assessment context and is fairly assumption-free. In particular, the two criteria can be used for discriminating between non-nested model structures and, more importantly, the ‘true’ system is not required to belong to the considered set of models. Should the true system belong to the model set, the two proposed criteria will asymptotically reduce to some well-known structure selection criteria. This is believed to be a desirable feature of our proposals. On the other hand, it provides a nice cross-validation interpretation of some well-known model structure selection rules. Also, the cross-validation interpretation helps one to choose which criteria to use in a given application

The paper also has a second purpose, somewhat decoupled from that mentioned above. It contains an extensive survey of the literature that is useful in its own right.     

Nonholonomic Multibody Dynamics

The paper deals with the nonholonomic multibody system dynamics from apoint of view which is caused by some actual applications in high-tecareas like high-speed train technology or biomechanics of somedisciplines in high-performance sports. Obviously, looking at suchproblems, there are very close connections between classical analyticaldynamics, differential geometry and modern control theory. But theseconnections cannot be used to get new composed results in solvingcomplicated problems of multibody system dynamics because correspondingsoftware tools are not enough in tune with each other. This paper willgive some ideas for developing a unified basis for modeling, simulationand control of nonholonomic multibody systems.First, a derivative-free approach for generating Lagrangian motionequations of multibody systems with kinematical tree structure as wellas for constrained multibody systems is given. This has been done byusing differential-geometric concepts in a Riemannian space. Secondly,the well-known theorem of Frobenius is considered with respect to itsclassical interpretation by the so-called object of nonholonomy as wellas by its modern interpretation in the nonlinear control theory usingLie-brackets. The ideas are illustrated by the classical rollingcondition and edge condition on double-curved surfaces. Specialnumerical problems in simulation of multibody systems subject toadditional kinematic constraints are discussed. Finally threeapplications are given.     

Blackboard systems

The blackboard architecture is becoming an increasingly popular basis for the construction of problem-solving systems which operate in domains requiring qualitatively different kinds of knowledge to be applied in order to arrive at a solution to a problem. This paper presents the metaphor on which blackboard systems are based. The metaphor is then given an interpretation which constitutes the blackboard architecture. The structure of the blackboard database and its contents are considered from an evolutionary point of view. Finally, the paper considers some of the alternative approaches to the control of problem-solving in blackboard systems.     

地震资料的三维空间交互式层面追踪解释方法研究

地震资料的层面解释是对现有的地震层面数据进行分析和处理,然后再以各种直观的方式动态展示地质特征的物探方法,是各种地质和能源勘探中的一项重要技术。解释效果的好坏直接影响后继工作的效率和成败。传统地震资料的层面解释方法建立在对三维地震资料进行二维解释的基础上,这种方法简单便捷,但也有很多的不足之处,如资料利用率低、解释精度不高等。本文提到的剖面引导和数据子体引导是两种全新的三维空间交互式层面追踪解释方法,从控制层面追踪区域的大小、控制层面追踪的次序等多个方面很好地弥补了传统方法的不足并阐述了这两种方法的原理、优点并给出了具体的实现算法和效果图。     

Visual interpretation of hand gestures for human-computerinteraction: a review

The use of hand gestures provides an attractive alternative to cumbersome interface devices for human-computer interaction (HCI). In particular, visual interpretation of hand gestures can help in achieving the ease and naturalness desired for HCI. This has motivated a very active research area concerned with computer vision-based analysis and interpretation of hand gestures. We survey the literature on visual interpretation of hand gestures in the context of its role in HCI. This discussion is organized on the basis of the method used for modeling, analyzing, and recognizing gestures. Important differences in the gesture interpretation approaches arise depending on whether a 3D model of the human hand or an image appearance model of the human hand is used. 3D hand models offer a way of more elaborate modeling of hand gestures but lead to computational hurdles that have not been overcome given the real-time requirements of HCI. Appearance-based models lead to computationally efficient “purposive” approaches that work well under constrained situations but seem to lack the generality desirable for HCI. We also discuss implemented gestural systems as well as other potential applications of vision-based gesture recognition. Although the current progress is encouraging, further theoretical as well as computational advances are needed before gestures can be widely used for HCI. We discuss directions of future research in gesture recognition, including its integration with other natural modes of human-computer interaction     

A unified approach to smoothing formulas

Based on various approaches, several different solutions to the smoothing problem have been given. The relationships between these solutions are not immediate, although they solve the same problem. Making use of a certain framework from scattering theory, we derive two families of solutions, with equations evolving forwards and backwards in time, respectively. Within these families three major previous approaches are obtained as special cases, and their relationships are clarified. The set of solutions also contains as a fourth special case a (new) backwards analog of the innovations solution. The Mayne-Fraser two-filter formula belongs to the set of backwards solutions, and within this framework certain difficulties with its interpretation can be resolved.     

Kernel CMAC with improved capability.

The cerebellar model articulation controller (CMAC) has some attractive features, namely fast learning capability and the possibility of efficient digital hardware implementation. Although CMAC was proposed many years ago, several open questions have been left even for today. The most important ones are about its modeling and generalization capabilities. The limits of its modeling capability were addressed in the literature, and recently, certain questions of its generalization property were also investigated. This paper deals with both the modeling and the generalization properties of CMAC. First, a new interpolation model is introduced. Then, a detailed analysis of the generalization error is given, and an analytical expression of this error for some special cases is presented. It is shown that this generalization error can be rather significant, and a simple regularized training algorithm to reduce this error is proposed. The results related to the modeling capability show that there are differences between the one-dimensional (1-D) and the multidimensional versions of CMAC. This paper discusses the reasons of this difference and suggests a new kernel-based interpretation of CMAC. The kernel interpretation gives a unified framework. Applying this approach, both the 1-D and the multidimensional CMACs can be constructed with similar modeling capability. Finally, this paper shows that the regularized training algorithm can be applied for the kernel interpretations too, which results in a network with significantly improved approximation capabilities.     

基于数据融合的测井解释专家决策支持方法的研究

提出了在数据融合的基础上，应用产生式规则实现的测井解释专家决策支持方法，给出了知识库的数据库表示、推理机和冲突的解决办法。最后给出了一个应用实例。     

CERTAINTY FACTOR THEORY AND ITS IMPLEMENTATION IN AN INFORMATION SYSTEM-ORIENTED EXPERT SYSTEM SHELL

This article discusses some topics related to the MYCIN model for uncertainty handling in expert systems. Some previously identified problems in this model should be considered as evidence to support the point of view that the probabilistic interpretation for measure of belief (MB) and measure of disbelief (MD) given by Shortliffe is inappropriate. In connection lo this, some results achieved by Heckerman are also reviewed and one of his arguments is questioned. According to this argument, the original interpretation for certainty factors implies a noncommutative method for evidence combination, and therefore, this interpretation should be abandoned. Problems similar to those identified by Adams in the original interpretation for certainty factors exist also in the interpretation recommended by Heckerman. Then, in the context of previous results stating that there is an isomorphic mapping from the evidence combination scheme for the likelihood ratio to the evidence combination function adopted in EMYCIN and its successors, we point out that the evidence combination scheme for the likelihood ratio suffers from a strong restriction. We remark upon the complaint that the MYCIN model cannot always function as well as one has expected. Implementation of the certainty factor mechanism in an information system-oriented expert system shell with some substantial changes is described     

A Markov random field model-based approach to image interpretation

An image is segmented into a collection of disjoint regions that form the nodes of an adjacency graph, and image interpretation is achieved through assigning object labels (or interpretations) to the segmented regions (or nodes) using domain knowledge, extracted feature measurements, and spatial relationships between the various regions. The interpretation labels are modeled as a Markov random field (MRF) on the corresponding adjacency graph, and the image interpretation problem is then formulated as a maximum a posteriori (MAP) estimation rule, given domain knowledge and region-based measurements. Simulated annealing is used to find this best realization or optimal MAP interpretation. This approach also provides a systematic method for organizing and representing domain knowledge through appropriate design of the clique functions describing the Gibbs distribution representing the pdf of the underlying MRF. A general methodology is provided for the design of the clique functions. Results of image interpretation experiments on synthetic and real-world images are described     

Real and complex polynomial stability and stability domain construction via network realizability theory

Network realzability theory provides the basis for a unified approach to the stability of a polynomial or a family of polynomials. In this paper conditions are given, in terms of certain decompositions of a given polynomial, that are necessary and sufficient for the given polynomial to be Hurwitz. These conditions facilitate the construction of stability domains for a family of polynomials through the use of linear inequalities. This approach provides a simple interpretation of recent results for polynomials with real coefficients and also leads to the formulation of corresponding results for the case of polynomials with complex coefficients.     

线性离散事件动态系统在广义反馈律下的动态特性分析*

基于极大代数,一类离散事件动态系统可被看作为“线性”系统。本文讨论这类系统在广义反馈律下的动态特性,证明了这类系统最终呈现周期性,还研究了系统参数发生摄动时其性能的变化特点,给出了具体例子来解释广义反馈律的物理意义和证实文中结论。