On computation of supremal controllable, normal sublanguages

In this paper, we present an algorithm for the computation of the controllable, normal sublanguage of a given language, encountered in the solution of the supervisory control of discrete-event systems under partial observation. The algorithm produces the desired result under certain assumptions on the plant and the event projection map. In particular, the plant has to be nonblocking. The advantage of the algorithm over the solution available in the literature is that it does not involve iterations on the supremal controllable sublanguage and supremal normal sublanguage operators.     

Formulas for a class of controllable and observable sublanguages larger than the supremal controllable and normal sublanguage

In this paper, we give some new methods for synthesis of controllers of discrete event dynamical systems (DEDS) with partial event informations. Given a regular target language L, we construct some effective computable algorithms for computing the controllable and observable sublanguages of L. We show that any one of these controllable and observable sublanguages obtained by our algorithms is larger than the supremal controllable and normal sublanguage of L.     

Formulas for calculating supremal controllable and normal sublanguages

Supremal controllable and normal sublanguages have been shown to play an important role in supervisor synthesis. In this paper, we discuss the computation of supremal controllable and normal sublanguages. We derive formulas for both supremal controllable sublanguages and supremal normal sublanguages when the languages involved are closed. As a result, those languages can be computed without applying recursive algorithms. We also discuss those aspects of these formulas.     

On supremal languages of classes of sublanguages that arise in supervisor synthesis problems with partial observation

This paper characterizes the class of closed and (M, N)-recognizable languages in terms of certain structural aspects of relevant automata. This characterization leads to algorithms that effectively compute the supremal (M, N)-recognizable sublanguage of a given language. One of these algorithms is used, in an alternating manner with an algorithm which yields the supremal (∑_u, N)-invariant resulting algorithm is proved. An example illustrates the use of these algorithms. This research was supported in part by the Air Force Office of Scientific Research under Grant No. AFOSR-86-0029, in part by the National Science Foundation under Grant No. ECS-8412100, and in part by the DoD Joint Services Electronics Program through the Air Force Office of Scientific Research (AFSC) Contract No. F49620-86-C-0045     

Acquisition of selectional patterns in sublanguages

When implementing computational lexicons it is important to keep in mind the texts that a NLP system must deal with. Words relate to each other in many different, often odd ways this information is rarely found in dictionaries, and it is quite hard to deduce a priori. In this paper we present a technique for the acquisition of statistically significant selectional restrictions from corpora and discuss the results of an experimental application with reference to two specific sublaguages (legal and commercial). We show that there are important cooccurrence preferences among words which cannot be established a priori as they are determined for each choice of sublanguage. The method for detecting cooccurrences is based on the analysis of word associations augmented with syntactic markers and semantic tags. Word pairs are extracted by a morphosyntactic analyzer and clustered according to their semantic tags. A statistical measure is applied to the data to evaluate the sigificance of any relations detected. Selectional restrictions are acquired by a two-step process. First, statistically prevailing coarse grained conceptual patterns are used by a linguist to identify the relevant selectional restrictions in sublanguages. Second, semiautomatically acquired coarse selectional restrictions are used as the semantic bias of a system, ARIOSTO_LEX, for the automatic acquisition of a case-based semantic lexicon.     

Decision procedures for elementary sublanguages of set theory

In this paper we prove the decidability of the class of unquantified formulae of set theory involving the operators , , , \, {·}, pred _< and the predicates =, , , Finite, where pred _<(s) denotes the collection of all sets having rank strictly less than the rank of s.This work generalizes and combines earlier results published in the same series of papers.This work has been partially supported by ENI and ENIDATA within the AXL project.     

Characterization of co-observable languages and formulas for their super/sublanguages

We present fixed-point based characterization of several classes of co-observable languages that are of interest in the context of decentralized supervisory control of discrete-event systems, including C&P /spl or/ D&A co-observable languages, C&P co-observable languages, and D&A co-observable languages. We also provide formulas for computing super/sublanguages for each of these classes. In cases where the class of co-observable languages is not closed under intersection/union, we provide upper/lower bound of the super/sublanguage formula we present. The computation of super/sublanguages and also computation of their upper/lower bounds has lead to the introduction of other classes of co-observable languages, namely, strongly C&P co-observable languages, strongly D&A co-observable languages, locally observable languages, and strongly locally observable languages. Fixed-point based characterization of all the above language classes is also given, and their closure under intersection/union is investigated. We also study whether the fixed-point operator preserves prefix closure, relative closure (also called L/sub m/(G)-closure), and controllability.     

Symbolic computation and observable effect for the (2 + 1)-dimensional symmetric regularized-long-wave equation from strongly magnetized cold-electron plasmas

In this paper, with the aid of computerized symbolic computation, we use the generalized hyperbolic-function method to obtain new families of exact analytic solutions for the (2 + 1)-dimensional symmetric regularized-long-wave equation. This equation describes weakly nonlinear ion-acoustic and space-charge waves in strongly magnetized cold-electron plasmas. The families we obtain consist of solitary waves and trigonometric functions. We outline an observable (2 + 1)-dimensional effect that could be of interest to future experiments on space and laboratory plasma systems. The usage of the Wu elimination method has also been addressed.     

The operation of infimal/supremal convolution in mathematical economics

The infimal convolution operation arises in mathematical economics in the analysis of several problems. In this paper we first present a survey and summarize two previous papers by the authors on the classic firm's cost-minimization problem. Moreover, we present a new application: the analytical solution of the utility maximization problem which we shall obtain applying the supremal convolution operation.     

聚苯胺包覆短碳纤维等效介电常数的二维模拟计算

计算机模拟与优化可有效避免实验设计的盲目性.采用Matlab 6.5软件对包覆型短碳纤维的等效电磁参数进行了模拟和计算,并讨论了包覆层体积分数和短碳纤维长径比对等效电磁参数的影响.结果表明:等效介电常数随着包覆层体积分数的增大而增大,短碳纤维的长径比<30时,影响较大.包覆型短碳纤维的等效电磁参数方程的模拟结果与实验结果相对误差小于10%.     

Synthesis of controllable and normal sublanguages for discrete-event systems using a coordinator

Synthesis of normal or controllable and normal sublanguages of global specification languages without computation of the global modular plant is a difficult problem. In this paper, these sublanguages are computed using a coordinator. We recall the notion of conditional controllability, introduce a notion of conditional normality, and prove necessary and sufficient conditions where such a computation is possible. Specifically, we show that conditionally controllable and conditionally normal languages computed by our method are controllable and normal with respect to the global plant. The optimality (supremality) of the resulting languages is also discussed.     

Supremal and maximal sublanguages arising in supervisor synthesis problems with partial observations

The paper studies in a unified manner both the class of closed, (_u,N)-invariant, and (M, N)-recognizable sublanguages and the class of closed, (_u,N)-invariant, and (M, _c,N)-controllable sublanguages of a given languageL that arise in supervisor synthesis problems of discrete event dynamical systems with partial observations. The supremal element of the former class is often too restrictive, and it is natural to study maximal elements of the latter class. A procedure which computes such a maximal element as a limit of a decreasing sequence of sublanguages ofL is presented. Each term of the sequence is shown to be regular if a slightly modified procedure is used.This research was supported in part by the Air Force Office of Scientific Research under Grant AFOSR-86-0029, in part by the National Science Foundation under Grant ECS-8617860, and in part by the DoD Joint Services Electronics Program through the Air Force Office of Scientific Research (AFSC) Contract F49620-86-C-0045.     

Maximal order reduction and supremal (A,B)-invariant and controllability subspaces

Given the system{A,B,C,E}the supremal (A,B)-invariant and controllability subspaces are studied and their dimensions are explicitly determined as functions of the number of zeros and the degree of the determinant of the interactor. This is done by solving the problem of the maximal order reduction via linear state feedback.     

Verification and control of partially observable probabilistic systems

We present automated techniques for the verification and control of partially observable, probabilistic systems for both discrete and dense models of time. For the discrete-time case, we formally model these systems using partially observable Markov decision processes; for dense time, we propose an extension of probabilistic timed automata in which local states are partially visible to an observer or controller. We give probabilistic temporal logics that can express a range of quantitative properties of these models, relating to the probability of an event’s occurrence or the expected value of a reward measure. We then propose techniques to either verify that such a property holds or synthesise a controller for the model which makes it true. Our approach is based on a grid-based abstraction of the uncountable belief space induced by partial observability and, for dense-time models, an integer discretisation of real-time behaviour. The former is necessarily approximate since the underlying problem is undecidable, however we show how both lower and upper bounds on numerical results can be generated. We illustrate the effectiveness of the approach by implementing it in the PRISM model checker and applying it to several case studies from the domains of task and network scheduling, computer security and planning.     

Information capacity of a quantum observable

In this paper we consider the classical capacities of quantum-classical channels corresponding to measurement of observables. Special attention is paid to the case of continuous observables. We give formulas for unassisted and entanglement-assisted classical capacities C and C _ea and consider some explicitly solvable cases, which give simple examples of entanglement-breaking channels with C < C _ea. We also elaborate on the ensemble-observable duality to show that C _ea for the measurement channel is related to the χ-quantity for the dual ensemble in the same way as C is related to the accessible information. This provides both accessible information and the χ-quantity for quantum ensembles dual to our examples.     

Computation of reachable and observable realizations of spatial filters

The input-output behaviour of a two-dimensional linear filter is defined by a formal power series in two variables- If the power series is rational, the dynamics of the filter is described by updating equations on finite dimensional local state spaces. The notions of local reachability and observability are defined in a natural way and an algorithm for obtaining a reachable and observable realization is given.

In general reachability and observability do not imply the minimality of the realization. Nevertheless the dimension of a minimal realization is the least rank in a family of Hankel matrices.