In some daily tasks, such as pick and place, the robot is requested to reach with its hand tip a desired target location while it is operating in its environment. Such tasks become more complex in environments cluttered with obstacles, since the constraint for collision-free movement must be also taken into account. This paper presents a new technique based on genetic algorithms (GAs) to solve the path planning problem of articulated redundant robot manipulators. The efficiency of the proposed GA is demonstrated through multiple experiments carried out on several robots with redundant degrees-of-freedom. Finally, the computational complexity of the proposed solution is estimated, in the worst case.

This paper describes an accurate and robust text alignment system for structurally different languages. Among structurally different languages such as Japanese and English, there is a limitation on the amount of word correspondences that can be statistically acquired. The main reason for this is the systems of functional (closed) words are quite different in the two languages. The proposed method makes use of two kinds of word correspondences in aligning bilingual texts. One is a bilingual dictionary of general use. The other is the word correspondences that are statistically acquired in the alignment process. Our method gradually determines sentence pairs (anchors) that correspond to each other by relaxing parameters. The method, by combining two kinds of word correspondences, achieves adequate word correspondences for complete alignment. As a result, texts of various length and of various genres in structurally different languages can be aligned with high precision. Experimental results show our system outperforms conventional methods for various kinds of Japanese–English texts.

1. Joint Venture Prograamme at Cranfield (UK)

TheJoint Venture Programme, newly launched by the Cranfield School ofManagement, offers help to companies that are looking to expand their businessin developing countries. It is claimed that valuable European Community (EU)grants are being lost, and the Cranfield initiative offers a fast track throughwhat they describe as the bureaucracy involved in making applications for aid todevelop partnerships abroad. This is particularly true of companies involvedwith automation and robotics who because of their intense development andmarketing activities fail to take advantage not only of EU programmes that offerfinancial assistance, but even the help that is at hand from their owngovernment's initiatives.

A practical implementation of a genetic algorithm for routing a real autonomous robot through a changing environment is described. Moving around in a production plant the robot collects information about its environment and stores it in a temporal map, which is virtually a square grid, taking account of changing obstacles. The evolutional optimizer continuously searches for short paths in this map using string representations of paths as chromosomes. The main features of the implementation include physical realization, random walk exploration, temporal mapping, and dedicated genetic operators.

Let G be a loopless 2-connected graph whose largest cycle has c edges, and whose largest bond has c* edges. We show that |E(G)| [les ] ½cc*.

This paper presents the software package SYMORO+ for the automaticsymbolic modelling of robots. This package permits to generate the directgeometric model, the inverse geometric model, the direct kinematic model, theinverse kinematic model, the dynamic model, and the inertial parametersidentification models.

The structure of the robots can be serial, treestructure or containing closed loops. The package runs on Sun stations and PCcomputers, it has been developed under MATHEMATICA and Clanguage. In this paper we give an overview of the algorithms used in thedifferent models; the computational cost of the dynamic models of the PUMArobot are given.

The popular method of enumerating the primes is the Sieve of Eratosthenes. It can be programmed very neatly in a lazy functional language, but runs rather slowly. A little-known alternative method is the Wheel Sieve, originally formulated as a fast imperative algorithm for obtaining all primes up to a given limit, assuming destructive access to a bit-array. This article describes functional variants of the wheel sieve that enumerate all primes as a lazy list.

An [n, k, r]-partite graph is a graph whose vertex set, V, can be partitioned into n pairwise-disjoint independent sets, V1, …, Vn, each containing exactly k vertices, and the subgraph induced by Vi ∪ Vj contains exactly r independent edges, for 1 [les ] i < j [les ] n. An independent transversal in an [n, k, r]-partite graph is an independent set, T, consisting of n vertices, one from each Vi. An independent covering is a set of k pairwise-disjoint independent transversals. Let t(k, r) denote the maximal n for which every [n, k, r]-partite graph contains an independent transversal. Let c(k, r) be the maximal n for which every [n, k, r]-partite graph contains an independent covering. We give upper and lower bounds for these parameters. Furthermore, our bounds are constructive. These results improve and generalize previous results of Erdo″s, Gyárfás and Łuczak [5], for the case of graphs.

Lemke and Kleitman [2] showed that, given a positive integer d and d (necessarily non-distinct) divisors of da1, …, ad there exists a subset Q ⊆ {1, …, d} such that d = [sum ]i∈Qai answering a conjecture of Erdo″s and Lemke. Here we extend this result, showing that, provided [sum ]p|d1/p [les ] 1 (where the sum is taken over all primes p), there is some collection from a1, …, ad which both sum to d and which can themselves be ordered so that each element divides its successor in the order. Furthermore, we shall show that the condition on the prime divisors is in some sense also necessary.

There is a wide diversity in the functioning and programming of robots designed and programmed to assist individuals with disabilities. The planning and structure of four rehabilitation robot implementations is presented. The first is the CURL language developed for human interface and the most widely used in this field. The second, MUSIIC, explores methods for direct manipulation of objects. RoboGlyph uses symbolic constructs to assist with the direction and programming of rehabilitation robots and finally a multi-tasking operating executive is discussed that controls a bilateral head operated telerobot. These four implementations reflect a wide range of interface concepts for the intended users.

We study three comonads derived from the comma construction. The induced coalgebras correspond to the three concepts displayed in the title of the paper. The comonad that yields the *-autonomous categories is, in essence, the Chu construction, which has recently awaken much interest in computer science. We describe its couniversal property. It is right adjoint to the inclusion of *-autonomous categories among autonomous categories, with lax structure-preserving morphisms. Moreover, this inclusion turns out to be comonadic: *-autonomous categories are exactly the Chu-coalgebras.

In this paper we define a logical framework, called &;lambda;TT, that is well suited for semantic analysis. We introduce the notion of a fibration [Lscr]1 : [Fscr]1 [xrarr ] [Cscr]1 being internally definableThe definability as used in this paper should not be confused with Bénabou's ‘definability’ (Bénabou 1985). in a fibration [Lscr]2 : [Fscr]2 [xrarr ] [Cscr]2. This notion amounts to distinguishing an internal category Lin [Lscr]2 and relating [Lscr]1 to the externalization of L through a pullback. When both [Lscr]1 and [Lscr]2 are term models of typed calculi [Lscr]1 and [Lscr]2, respectively, we say that [Lscr]1 is an internal typed calculus definable in the frame language [Lscr]2. We will show by examples that if an object language is adequately represented in λTT, then it is an internal typed calculus definable in the frame language λTT. These examples also show a general phenomenon: if the term model of an object language has categorical structure S, then an adequate encoding of the language in λTT imposes an explicit internal categorical structure S in the term model of λTT and the two structures are related via internal definability. Our categorical investigation of logical frameworks indicates a sensible model theory of encodings.

The traditional notions of strong and weak normalization refer to properties of a binary reduction relation. In this paper we explore an alternative approach to normalization, in which we bypass the reduction relation and instead focus on the normalization function, that is, the function that maps a term to its normal form. We work in an intuitionistic metalanguage, and characterize a normalization function as an algorithm that picks a canonical representative from the equivalence class of convertible terms. This means that we also get a decision algorithm for convertibility.Such a normalization function can be constructed by building an appropriate model and a function quote, which inverts the interpretation function. The normalization function is then obtained by composing the quote function with the interpretation function. We also discuss how to get a simple proof of the property that constructors are one-to-one, which is usually obtained as a corollary of Church–Rosser and normalization in the traditional sense.We illustrate this approach by showing how a glueing model (closely related to the glueing construction used in category theory) gives rise to a normalization algorithm for a combinatory formulation of Gödel System T. We then show how the method extends in a straightforward way when we add cartesian products and disjoint unions (full intuitionistic propositional logic under a Curry–Howard interpretation) and transfinite inductive types such as the Brouwer ordinals.