Le bilinguisme officiel (français-anglais) au Cameroun : un problème d’aménagement efficace

Le bilinguisme officiel (français-anglais) au Cameroun : un problème d'aménagement efficace — Cette étude vise à vérifier l'étendue de la prépondérance exclusive du français et de l'anglais dans la communication au sein de l'État camerounais, en raison de certaines contradictions (Renaud 1979 et 1987). Ces langues officielles sont censées y assurer les fonctions les plus hautes en présence de 236 langues autochtones. Ces dernières sont-elles réellement absentes des services publics? Quelles sont les attitudes des Camerounais envers elles et leurs communautés constitutionnelles respectives? Quelle serait une politique linguistique réaliste pour le Cameroun? Pour répondre à ces questions, nous avons, en 1993, soumis à 590 personnes dans les chefs-lieux administratifs des dix provinces du pays, un questionnaire fermé sur leurs choix de langue et les attentes linguistiques perçues par eux dans leurs contacts officiels. L'analyse des données a révélé l'existence d'une concurrence participative reflétant l'élargissement fonctionnel des langues non officielles. Une tension y est apparue entre le français et l'anglais, mais elle reflète les conflits politiques ambiants.S'agissant des attitudes, le répondant devait porter son jugement sur les langues officielles et leurs communautés constitutionnelles respectives, par rapport à sept différenciateurs sémantiques inspirés de Gardner et Smythe (1976). L'analyse révèle : une haute appréciation des répondants de chaque communauté pour leur première langue officielle, l'évaluation négative de leur deuxième langue officielle par les anglophones, l'apparition des stéréotypes négatifs envers le pidgin, et la meilleure image que les anglophones auraient de leur communauté.La concurrence participative entre langues officielles et non officielles, le nationalisme et la volonté d'ouverture des Camerounais, ainsi que leur aspiration à voir les hautes fonctions étendues aux langues locales, nous ont amené à proposer l'alphabétisation fonctionnelle en langues locales, pour la nécessaire valorisation des langues endogènes, dans un contexte minimisant la confrontation avec les langues officielles, et consacrant le passage du culturel à l'économique.Official Bilingualism (French-English) in Cameroon : A Question of Efficient Planning — This study aims at a verification of the extent of exclusive predominant usage of French and English in public offices in Cameroon, in communication within the Cameroonian State, since some contradictions exist (Renaud, 1979 and 1987). The official languages are supposed to assume the highest functions among 236 home languages. Are these actually absent from public services? What are the attitudes of Cameroonians toward these official languages and their respective communities as per the Cameroon Constitution? What would be a realistic language policy for Cameroon?To answer these questions, a closed survey on language choices and perceived expectations in official contacts was submitted in 1993 to 590 persons in the administrative headquarters of Cameroon's ten provinces. Data analysis showed participative competition as a reflection of a widening of functions assumed by non official languages. Tension between French and English was noticed, as a manifestation of local political conflicts.As concerns attitudes, those surveyed were asked to express their judgment on official languages and their respective communities, according to seven semantic differentials taken from Gardner and Smythe (1976). The analysis revealed : high levels of appreciation by members of each community, of their first official language, a negative evaluation by Anglophones of their second official language, the negative stereotypes of Pidgin English, a better image of their own community as perceived by Anglophones.On account of the participative competition between official and non official languages, the nationalism and open-mindedness of Cameroonians, as well as their aspiring to a widening of higher linguistic functions to include home languages, functional literacy in local languages is recommended, as a means to solve the necessary enhancement of endogenous languages, with minimal confrontation with official languages, as a consecration of an evolution from the cultural to the economic aspect of language

Deterministic meeting of sniffing agents in the plane

Two mobile agents, starting at arbitrary, possibly different times from arbitrary locations in the plane, have to meet. Agents are modeled as discs of diameter 1, and meeting occurs when these discs touch. Agents have different labels which are integers from the set of 0 to L-1. Each agent knows L and knows its own label, but not the label of the other agent. Agents are equipped with compasses and have synchronized clocks. They make a series of moves. Each move specifies the direction and the duration of moving. This includes a null move which consists in staying inert for some time, or forever. In a non-null move agents travel at the same constant speed, normalized to 1. We assume that agents have sensors enabling them to estimate the distance from the other agent (defined as the distance between centers of discs), but not the direction towards it. We consider two models of estimation. In both models an agent reads its sensor at the moment of its appearance in the plane and then at the end of each move. This reading (together with the previous ones) determines the decision concerning the next move. In both models the reading of the sensor tells the agent if the other agent is already present. Moreover, in the monotone model, each agent can find out, for any two readings in moments t1 and t2, whether the distance from the other agent at time t1 was smaller, equal or larger than at time t2. In the weaker binary model, each agent can find out, at any reading, whether it is at distance less than \r{ho} or at distance at least \r{ho} from the other agent, for some real \r{ho} > 1 unknown to them. Such distance estimation mechanism can be implemented, e.g., using chemical sensors. Each agent emits some chemical substance (scent), and the sensor of the other agent detects it, i.e., sniffs. The intensity of the scent decreases with the distance.Comment: A preliminary version of this paper appeared in the Proc. 23rd International Colloquium on Structural Information and Communication Complexity (SIROCCO 2016), LNCS 998

Robots with Lights: Overcoming Obstructed Visibility Without Colliding

Robots with lights is a model of autonomous mobile computational entities operating in the plane in Look-Compute-Move cycles: each agent has an externally visible light which can assume colors from a fixed set; the lights are persistent (i.e., the color is not erased at the end of a cycle), but otherwise the agents are oblivious. The investigation of computability in this model, initially suggested by Peleg, is under way, and several results have been recently established. In these investigations, however, an agent is assumed to be capable to see through another agent. In this paper we start the study of computing when visibility is obstructable, and investigate the most basic problem for this setting, Complete Visibility: The agents must reach within finite time a configuration where they can all see each other and terminate. We do not make any assumption on a-priori knowledge of the number of agents, on rigidity of movements nor on chirality. The local coordinate system of an agent may change at each activation. Also, by definition of lights, an agent can communicate and remember only a constant number of bits in each cycle. In spite of these weak conditions, we prove that Complete Visibility is always solvable, even in the asynchronous setting, without collisions and using a small constant number of colors. The proof is constructive. We also show how to extend our protocol for Complete Visibility so that, with the same number of colors, the agents solve the (non-uniform) Circle Formation problem with obstructed visibility

Quantum systems in a stationary environment out of thermal equilibrium

We discuss how the thermalization of an elementary quantum system is modified when the system is placed in an environment out of thermal equilibrium. To this aim we provide a detailed investigation of the dynamics of an atomic system placed close to a body of arbitrary geometry and dielectric permittivity, whose temperature $T_M$ is different from that of the surrounding walls $T_W$. A suitable master equation for the general case of an $N$-level atom is first derived and then specialized to the cases of a two- and three-level atom. Transition rates and steady states are explicitly expressed as a function of the scattering matrices of the body and become both qualitatively and quantitatively different from the case of radiation at thermal equilibrium. Out of equilibrium, the system steady state depends on the system-body distance, on the geometry of the body and on the interplay of all such parameters with the body optical resonances. While a two-level atom tends toward a thermal state, this is not the case already in the presence of three atomic levels. This peculiar behavior can be exploited, for example, to invert the populations ordering and to provide an efficient cooling mechanism for the internal state of the quantum system. We finally provide numerical studies and asymptotic expressions when the body is a slab of finite thickness. Our predictions can be relevant for a wide class of experimental configurations out of thermal equilibrium involving different physical realizations of two or three-level systems.Comment: 20 pages, 15 figures, published versio

Deaf, Dumb, and Chatting Robots, Enabling Distributed Computation and Fault-Tolerance Among Stigmergic Robot

We investigate ways for the exchange of information (explicit communication) among deaf and dumb mobile robots scattered in the plane. We introduce the use of movement-signals (analogously to flight signals and bees waggle) as a mean to transfer messages, enabling the use of distributed algorithms among the robots. We propose one-to-one deterministic movement protocols that implement explicit communication. We first present protocols for synchronous robots. We begin with a very simple coding protocol for two robots. Based on on this protocol, we provide one-to-one communication for any system of n \geq 2 robots equipped with observable IDs that agree on a common direction (sense of direction). We then propose two solutions enabling one-to-one communication among anonymous robots. Since the robots are devoid of observable IDs, both protocols build recognition mechanisms using the (weak) capabilities offered to the robots. The first protocol assumes that the robots agree on a common direction and a common handedness (chirality), while the second protocol assumes chirality only. Next, we show how the movements of robots can provide implicit acknowledgments in asynchronous systems. We use this result to design asynchronous one-to-one communication with two robots only. Finally, we combine this solution with the schemes developed in synchronous settings to fit the general case of asynchronous one-to-one communication among any number of robots. Our protocols enable the use of distributing algorithms based on message exchanges among swarms of Stigmergic robots. Furthermore, they provides robots equipped with means of communication to overcome faults of their communication device

Some remarks on quasi-Hermitian operators

A quasi-Hermitian operator is an operator that is similar to its adjoint in some sense, via a metric operator, i.e., a strictly positive self-adjoint operator. Whereas those metric operators are in general assumed to be bounded, we analyze the structure generated by unbounded metric operators in a Hilbert space. Following our previous work, we introduce several generalizations of the notion of similarity between operators. Then we explore systematically the various types of quasi-Hermitian operators, bounded or not. Finally we discuss their application in the so-called pseudo-Hermitian quantum mechanics.Comment: 18page

Antilinear deformations of Coxeter groups, an application to Calogero models

We construct complex root spaces remaining invariant under antilinear involutions related to all Coxeter groups. We provide two alternative constructions: One is based on deformations of factors of the Coxeter element and the other based on the deformation of the longest element of the Coxeter group. Motivated by the fact that non-Hermitian Hamiltonians admitting an antilinear symmetry may be used to define consistent quantum mechanical systems with real discrete energy spectra, we subsequently employ our constructions to formulate deformations of Coxeter models remaining invariant under these extended Coxeter groups. We provide explicit and generic solutions for the Schroedinger equation of these models for the eigenenergies and corresponding wavefunctions. A new feature of these novel models is that when compared with the undeformed case their solutions are usually no longer singular for an exchange of an amount of particles less than the dimension of the representation space of the roots. The simultaneous scattering of all particles in the model leads to anyonic exchange factors for processes which have no analogue in the undeformed case.Comment: 32 page

Strings from position-dependent noncommutativity

We introduce a new set of noncommutative space-time commutation relations in two space dimensions. The space-space commutation relations are deformations of the standard flat noncommutative space-time relations taken here to have position dependent structure constants. Some of the new variables are non-Hermitian in the most natural choice. We construct their Hermitian counterparts by means of a Dyson map, which also serves to introduce a new metric operator. We propose PTlike symmetries, i.e.antilinear involutory maps, respected by these deformations. We compute minimal lengths and momenta arising in this space from generalized versions of Heisenberg's uncertainty relations and find that any object in this two dimensional space is string like, i.e.having a fundamental length in one direction beyond which a resolution is impossible. Subsequently we formulate and partly solve some simple models in these new variables, the free particle, its PT-symmetric deformations and the harmonic oscillator.Comment: 11 pages, Late