Decentralized Hybrid Formation Control of Unmanned Aerial Vehicles

This paper presents a decentralized hybrid supervisory control approach for a team of unmanned helicopters that are involved in a leader-follower formation mission. Using a polar partitioning technique, the motion dynamics of the follower helicopters are abstracted to finite state machines. Then, a discrete supervisor is designed in a modular way for different components of the formation mission including reaching the formation, keeping the formation, and collision avoidance. Furthermore, a formal technique is developed to design the local supervisors decentralizedly, so that the team of helicopters as whole, can cooperatively accomplish a collision-free formation task

Diagrammatic state sums for 2D pin-minus TQFTs

The two dimensional state sum models of Barrett and Tavares are extended to unoriented spacetimes. The input to the construction is an algebraic structure dubbed half twist algebras, a class of examples of which is real separable superalgebras with a continuous parameter. The construction generates pin-minus TQFTs, including the root invertible theory with partition function the Arf-Brown-Kervaire invariant. Decomposability, the stacking law, and Morita invariance of the construction are discussed

Razumijevanje frazema kod hrvatskih učenika engleskoga jezika: Kontekst, kompozicionalnost i dob kao činitelji

There are many factors influencing the comprehension of idiomatic expressions in EFL context. These factors include, among others, age, context, familiarity and decomposability rate (the degree to which an idiom is susceptible to interpretation through simple analysis of the meanings of its individual components). For the purpose of determining how Croatian EFL learners of all levels (Elementary, Secondary, Undergraduate level, Graduate level) process idioms, a study was conducted by using multiple-choice questions and a Likert scale task in order to try and determine which of the abovementioned factors play greater role in idiom comprehension, i.e. if they influence processing to the same extent or if there exists a noticeable difference among them. The purpose of this paper is to set a direction for figurative language teaching in EFL situations by contributing to the existing body of knowledge on what facilitates the comprehension of idiomatic expressions.Brojni činitelji utječu na razumijevanje frazema u kontekstu učenja stranoga jezika. Oni su, između ostalog, dob, kontekst, poznavanje frazema te njegova kompozicionalnost (stupanj podložnosti frazema semantičkoj analizi pojedinih sastavnica). Istraživanje u kojem su korištena pitanja višestrukog izbora i Likertova skala provedeno je kako bi se utvrdio način na koji hrvatski učenici engleskoga jezika sa različitih obrazovnih razina (osnovna, sekundarna, preddiplomska, diplomska) razumijevaju frazeme te koji činitelji više utječu na njihovo razumijevanje, odnosno postoje li među činiteljima zamjetne razlike u utjecaju. Svrha ovoga rada je utvrditi smjer poučavanja figurativnog jezika u kontekstu poučavanja stranoga jezika nadograđujući postojeće znanje o činiteljima koji doprinose razumijevanju frazema

Razumijevanje frazema kod hrvatskih učenika engleskoga jezika: Kontekst, kompozicionalnost i dob kao činitelji

There are many factors influencing the comprehension of idiomatic expressions in EFL context. These factors include, among others, age, context, familiarity and decomposability rate (the degree to which an idiom is susceptible to interpretation through simple analysis of the meanings of its individual components). For the purpose of determining how Croatian EFL learners of all levels (Elementary, Secondary, Undergraduate level, Graduate level) process idioms, a study was conducted by using multiple-choice questions and a Likert scale task in order to try and determine which of the abovementioned factors play greater role in idiom comprehension, i.e. if they influence processing to the same extent or if there exists a noticeable difference among them. The purpose of this paper is to set a direction for figurative language teaching in EFL situations by contributing to the existing body of knowledge on what facilitates the comprehension of idiomatic expressions.Brojni činitelji utječu na razumijevanje frazema u kontekstu učenja stranoga jezika. Oni su, između ostalog, dob, kontekst, poznavanje frazema te njegova kompozicionalnost (stupanj podložnosti frazema semantičkoj analizi pojedinih sastavnica). Istraživanje u kojem su korištena pitanja višestrukog izbora i Likertova skala provedeno je kako bi se utvrdio način na koji hrvatski učenici engleskoga jezika sa različitih obrazovnih razina (osnovna, sekundarna, preddiplomska, diplomska) razumijevaju frazeme te koji činitelji više utječu na njihovo razumijevanje, odnosno postoje li među činiteljima zamjetne razlike u utjecaju. Svrha ovoga rada je utvrditi smjer poučavanja figurativnog jezika u kontekstu poučavanja stranoga jezika nadograđujući postojeće znanje o činiteljima koji doprinose razumijevanju frazema

Conservation Laws and Integrability of a One-dimensional Model of Diffusing Dimers

We study a model of assisted diffusion of hard-core particles on a line. The model shows strongly ergodicity breaking : configuration space breaks up into an exponentially large number of disconnected sectors. We determine this sector-decomposion exactly. Within each sector the model is reducible to the simple exclusion process, and is thus equivalent to the Heisenberg model and is fully integrable. We discuss additional symmetries of the equivalent quantum Hamiltonian which relate observables in different sectors. In some sectors, the long-time decay of correlation functions is qualitatively different from that of the simple exclusion process. These decays in different sectors are deduced from an exact mapping to a model of the diffusion of hard-core random walkers with conserved spins, and are also verified numerically. We also discuss some implications of the existence of an infinity of conservation laws for a hydrodynamic description.Comment: 39 pages, with 5 eps figures, to appear in J. Stat. Phys. (March 1997

Energy dispersed solutions for the (4+1)-dimensional Maxwell-Klein-Gordon equation

This article is devoted to the mass-less energy critical Maxwell-Klein-Gordon system in 4+1 dimensions. In earlier work of the second author, joint with Krieger and Sterbenz, we have proved that this problem has global well-posedness and scattering in the Coulomb gauge for small initial data. This article is the second of a sequence of three papers of the authors, whose goal is to show that the same result holds for data with arbitrarily large energy. Our aim here is to show that large data solutions persist for as long as one has small energy dispersion; hence failure of global well-posedness must be accompanied with a non-trivial energy dispersion.Comment: 63 page