39 research outputs found
A proposal of PSO particles' initialization, for costly unconstrained optimization problems: ORTHOinit
Abstract. A proposal for particlesâ initialization in PSO is presented and discussed, with focus on costly global unconstrained optimization problems. The standard PSO iteration is reformulated such that the trajectories of the particles are studied in an extended space, combining
particlesâ position and speed. To the aim of exploring effectively and efficiently the optimization search space since the early iterations, the particles are initialized using sets of orthogonal vectors in the extended space (orthogonal initialization, ORTHOinit). Theoretical derivation and
application to a simulation-based optimization problem in ship design are presented, showing the potential benefits of the current approach
An Estimation of Distribution Particle Swarm Optimization Algorithm
In this paper we present an estimation of distribution par-ticle swarm optimization algorithm that borrows ideas from recent de-velopments in ant colony optimization. In the classical particle swarm optimization algorithm, particles exploit their individual memory to ex-plore the search space. However, the swarm as a whole has no means to exploit its collective memory (represented by the array of pbests) to guide its search. This causes a re-exploration of already known bad regions of the search space, wasting costly function evaluations. In our approach, we use the swarms collective memory to estimate the distribu-tion of promising regions in the search space and probabilistically guide the particles movement towards them. Our experiments show that this approach is able to find similar or better solutions than the standard particle swarm optimizer with fewer function evaluations
AnĂlise sociofuncionalista da variaĂĂo de concordĂncia verbal em construĂĂes de voz passiva sintĂtica em textos jornalĂsticos cearenses
FundaĂĂo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolĂgicoNosso trabalho investiga como a realizaĂĂo variĂvel de concordĂncia verbal em construĂĂes de
voz passiva sintĂtica, com a alternĂncia entre a presenĂa e a ausĂncia de marca explĂcita de
plural no verbo de 3Ă pessoa, apresenta-se no atual contexto linguĂstico cearense,
especificamente em dois jornais locais: O Povo e DiĂrio do Nordeste. Para isso, selecionamos
240 ediĂĂes, durante o perĂodo de janeiro a dezembro de 2016, levando-se em consideraĂĂo trĂs
gĂneros textuais: editoriais, artigos de opiniĂo e notĂcias. No total, coletamos 121 dados
referentes Ă variaĂĂo de concordĂncia verbal com a construĂĂo de voz passiva sintĂtica, os quais
foram submetidos ao programa computacional estatĂstico Goldvarb X, que gerou frequĂncias e
pesos relativos que serviram de base para a descriĂĂo e anĂlise dos dados. O programa apontou
que a ausĂncia de marca explĂcita de plural no verbo com a voz passiva sintĂtica Ă condicionada
essencialmente por dois grupos de fatores: um linguĂstico, forma verbal, e outro
extralinguĂstico, gĂnero textual. Contudo, o nĂmero de dados em que o verbo apresenta marca
explĂcita de plural (59,5%) mostrou-se mais representativo do que o somatĂrio dos dados em
que o verbo nĂo consta da marca explĂcita de plural (40,5%). Para o desenvolvimento deste
trabalho, utilizamo-nos dos pressupostos teĂrico-metodolĂgicos da SociolinguĂstica
Variacionista (LABOV, 2008), conjugados a princĂpios funcionalistas, em especial, o PrincĂpio
da MarcaĂĂo (GIVĂN, 1995) e o PrincĂpio da Expressividade (DU BOIS & VOTRE, 2012).
AlĂm da possĂvel mudanĂa em direĂĂo Ă indeterminaĂĂo com a construĂĂo de voz passiva
sintĂtica, concluĂmos que, no grupo de fatores linguĂsticos forma verbal, as formas perifrĂsticas
e infinitivas, especialmente com esse tipo de construĂĂo, tendem a ser realizadas sem a presenĂa
do morfema de plural, como uma manobra para reduzir ou anular o esforĂo de codificaĂĂo,
motivada em termos de expressividade e de eficĂcia comunicativa. JĂ em relaĂĂo ao grupo
extralinguĂstico gĂnero textual, hĂ tendĂncia de que formas mais marcadas ocorram em
contextos mais marcados e as menos marcadas em contextos menos marcados, ou seja, formas
verbais mais marcadas em construĂĂes de voz passiva sintĂtica â com a presenĂa de morfema
de plural â tendem a ocorrer em contextos mais marcados, como no gĂnero textual editorial,
ao passo que formas verbais menos marcadas â com a ausĂncia de morfema de plural â tendem
a ocorrer em contextos menos marcados, como no gĂnero textual notĂcia.Our work investigate how the variable fulfillment of verbal concord in synthetic passive voice
constructions, alternating between the presence and absence of explicit mark of plural in the
third person of verb forms, is presented in the current linguistic context of CearĂ, specifically
in two local newspapers: O Povo and DiĂrio do Nordeste. In order to reach this goal, we
selected 240 editions focusing on three textual genres: editorial, opinion article, and news from
January to December, 2016. A number of 121 data concerning the variation of verbal concord
with the synthetic passive voice construction was selected and submitted to the statistical
computer program Goldvarb X which generated frequencies and relative weight that served as
basis to the description and data analysis. The program pointed out that the absence of the
explicit mark of the plural in the verb with the synthetic passive voice is subject to two groups
of factors: one linguistic, verbal form; and the other extralinguistic, textual genre. However, the
number of data in which the verb presents explicit mark of plural (59.5%) claimed to be more
representative than the amount of data in which the verb is not present in the explicit mark of
plural (40.5%). In order to develop this research, we used as theoretical-methodological basis
the Sociolinguistic Variation (LABOV, 2008), attached to the functionalist principles, notably
to the Markedness Principle (GIVĂN, 1995) and the Principle of Expressiveness (DU BOIS &
VOTRE, 2012). Besides the possible change towards the indetermination due to the use of the
synthetic passive voice, we conclude that as for the group verbal form the periphrastic and
infinitive forms, especially with this type of construction. The aforementioned forms tend to be
fulfilled without the presence of the plural morpheme as a device to reduce or set aside the
codification effort and motivated in terms of expressiveness and communicative accuracy. As
far as the extralinguistic group textual genre is concerned, there is a tendency that more marked
forms occur in contexts that are more marked and less marked forms occur in contexts that are
less marked as well. In summary, more marked verbal forms in synthetic passive voice â with
the presence of a plural morpheme - tend to appear in contexts that are more marked such as
in textual genre editorial whereas less marked verbal forms â absence of plural morpheme â
tend to occur in contexts that are less marked such as in the news textual genr