Information Structure Constraints Research Articles

Prosodic marking of contrast in LSFB (French Belgian Sign Language)

Abstract This paper examines the relationships between information structure and prosody in LSFB (French Belgian Sign Language), focusing on the marking of contrast. A recurrent assertion in the literature is that contrast is always marked by prosodic prominence. We discuss this interaction at the manual level by investigating the connections between the presence or absence of a manual prosodic marker and the contrastive or non-contrastive character of a sign. To explore this connection, we examine data related to the holds, dominance reversals, repetitions, and variations in duration and displacement produced on 977 signs by four native LSFB signers. We also assign a certain degree of prominence to every sign depending on the number of cues employed by a participant. Data are analysed using descriptive and inferential statistics (Chi-squared test, Mann-Whitney U test, or Kruskal-Wallis test). The results show that contrast has its own prosodic marking at the manual level in LSFB and that contrastive signs are more prominent than non-contrastive ones. The prevailing cues used to encode contrast are variations in displacement or relative duration, and combinations of relative duration and displacement. The interactions between prosody, information structure, and articulatory constraints are discussed to explain the different patterns highlighted in the data sample.

Locality and expectation effects in Hindi preverbal constituent ordering

We investigate the relative impact of two influential theories of language comprehension, viz., Dependency Locality Theory (Gibson, 2000; DLT) and Surprisal Theory (Hale, 2001; Levy, 2008), on preverbal constituent ordering in Hindi, a predominantly SOV language with flexible word order. Prior work in Hindi has shown that word order scrambling is influenced by information structure constraints in discourse. However, the impact of cognitively grounded factors on Hindi constituent ordering is relatively underexplored. We test the hypothesis that dependency length minimization is a significant predictor of syntactic choice, once information status and surprisal measures (estimated from n-gram i.e., trigram and incremental dependency parsing models) have been added to a machine learning model. Towards this end, we setup a framework to generate meaning-equivalent grammatical variants of Hindi sentences by linearizing preverbal constituents of projective dependency trees in the Hindi-Urdu Treebank (HUTB) corpus of written text. Our results indicate that dependency length displays a weak effect in predicting reference sentences (amidst variants) over and above the aforementioned predictors. Overall, trigram surprisal outperforms dependency length and parser surprisal by a huge margin and our analyses indicate that maximizing lexical predictability is the primary driving force behind preverbal constituent ordering choices in Hindi. The success of trigram surprisal notwithstanding, dependency length minimization predicts non-canonical reference sentences having fronted direct objects over variants containing the canonical word order, cases where surprisal estimates fail due to their bias towards frequent structures and word sequences. Locality effects persist over the Given-New preference of subject-object ordering in Hindi. Accessibility and local statistical biases discussed in the sentence processing literature are plausible explanations for the success of trigram surprisal. Further, we conjecture that the presence of case markers is a strong factor potentially overriding the pressure for dependency length minimization in Hindi. Finally, we discuss the implications of our findings for the information locality hypothesis and theories of language production.

Distributed Value Function Approximation for Collaborative Multiagent Reinforcement Learning

In this article, we propose several novel distributed gradient-based temporal-difference algorithms for multiagent off-policy learning of linear approximation of the value function in Markov decision processes with strict information structure constraints, limiting interagent communications to small neighborhoods. The algorithms are composed of the following: first, local parameter updates based on the single-agent off-policy gradient temporal-difference learning algorithms, including the eligibility traces with state-dependent parameters and, second, linear stochastic time-varying consensus schemes, represented by directed graphs. The proposed algorithms differ in their form, definition of eligibility traces, selection of time scales, and the way of incorporating consensus iterations. The main contribution of this article is a convergence analysis based on the general properties of the underlying Feller-Markov processes and the stochastic time-varying consensus model. We prove under general assumptions that the parameter estimates generated by all the proposed algorithms weakly converge to the corresponding ordinary differential equations with precisely defined invariant sets. It is demonstrated how the adopted methodology can be applied to temporal-difference algorithms under weaker information structure constraints. The variance reduction effect of the proposed algorithms is demonstrated by formulating and analyzing an asymptotic stochastic differential equation. Specific guidelines for the communication network design are provided. The algorithms' superior properties are illustrated by characteristic simulation results.

The effects of information structure in the processing of word order variation in the second language

Traditionally, it has been claimed that the non-canonical word order of passives makes them inherently more difficult to comprehend than their canonical active counterparts both in the first (L1) and second language (L2). However, growing evidence suggests that non-canonical word orders are not inherently more difficult to process than canonical counterparts when presented with discourse contexts that license their information structure constraints. In an eye-tracking experiment, we investigated the effect of information structure on the online processing of active and passive constructions and whether this effect differed in monolinguals and L1-Spanish–L2-English speakers. In line with previous corpus studies, our results indicated that there was an interaction between word order and information structure according to which passive sentences were much more costly to process with new–given information structure patterns. Crucially, we failed to find evidence that the effect of information structure on word order constraints in comprehension differed between monolingual and L2 speakers.

Knowledge of English Focus Constructions by Saudi Learners of English: Usage-Based Approach

The current study investigates whether Saudi-Arabic speaking learners of English are sensitive to the information-structure constraints and frequency distribution when dealing with the syntactic means of information highlighting in English. Ninety-nine participants of different proficiency levels in English completed an acceptability rating task that asked participants to rate the target constructions in two different contexts eliciting either a narrow focus, in which the use of the target constructions was acceptable (felicitous), or a broad focus in which their use was inacceptable (infelicitous). The findings indicate that participants were sensitive to the contextual effect, as evident from participants' higher acceptability ratings in the felicitous context than the infelicitous context. Moreover, frequency impact was evident in their higher acceptability ratings in the felicitous context for the comparatively frequent constructions. Differences in the perceived acceptability of the target constructions by participants suggest a role for proficiency. All in all, the results obtained in this study supported the general predictions of usage-based approaches to SLA and shed light on the role of cognitive processes in the acquisition of the target constructions..

Spectra Restoration of Bone-Conducted Speech via Attention-Based Contextual Information and Spectro-Temporal Structure Constraint

Spectra Restoration of Bone-Conducted Speech via Attention-Based Contextual Information and Spectro-Temporal Structure Constraint

Anticipating information structure: An event-related potentials study of focus assignment via the it-cleft

The present study uses event-related potentials to investigate the role of prediction in the processing of information structure, a domain of language that belongs to the level of the discourse. Twenty-three native speakers of English read short contexts including three Noun Phrases (NPs) (e.g., Either an adviser or an agent can be helpful to a banker), followed by a wh-question that established the discourse role of each referent (In your opinion, which of the two should a banker hire?). The NP that the question was about (banker) was the Topic, and the two NPs that could fill the slot opened by the wh-question (adviser, agent) were the Focus NPs. The participants’ brain activity was recorded with EEG while they read the responses to the wh-questions, which differed along two dimensions: (1) the availability of the it-cleft construction (In my opinion, [it is] an agent…), a Focus-devoted device that makes Focus assignment predictable in the response; and (2) the discourse role of the target noun (Focus, Topic), which corresponds to the first referent in the response (In my opinion, [it is] an agent/a banker…). Crucially, we manipulated the phonological properties of the Focus and Topic nouns such that, if the Topic noun began with a consonant (e.g., a banker), both nouns that could fill the slot opened by the wh-question began with a vowel (e.g., an agent, an adviser) (counterbalanced in the overall design). This allowed us to measure effects of prediction at the prenominal article, before the integration of semantic and discourse information took place. The analyses on prenominal articles revealed an N400 effect for articles that were unexpected based on the phonological properties of the Focus nouns, but only in the conditions with the it-cleft. This effect emerged between 250 and 400 ms, with a frontal bias. The analyses on the noun revealed that violations of information structure (i.e., cases where the it-cleft was followed by the Topic noun) yielded a broadly distributed P600 effect, relative to appropriately clefted (i.e., focused) nouns. A similar (but numerically less robust) effect emerged for Topic relative to Focus NPs in the conditions without the it-cleft, suggesting that, in the absence of a constraining cue, comprehenders still assigned Focus to the first referent in the response. Overall, these results suggest that, when reading answers to wh-questions, comprehenders use information structure constraints (i.e., prior context + the it-cleft) to anticipate the form that the response should take (i.e., how information should be packaged).

Context and Information Structure constraints on factivity: the case of know

Do factive-presuppositional interpretations of know emerge out of its semantic features, or are they the outcome of different structural patterns displayed by the sentence? The present work discusses the ambiguity of know and the reasons behind its fluctuating factive and non factive behavior looking at the role of Information Structure. Starting from views that account for the ambiguity of know as the result of its inherent semantic polysemy and from the role played by the context of discourse, we suggest that know-sentences can receive factive or non factive interpretations also based on the distribution of Topic and Focus units. The view put forward suggests categorizing the interpretation of complement clauses governed by know as factive or non factive not only on the basis of the (un-)availability of the information they carry in the addressee's Long-Term Memory, but also in relation to how such information is activated in Short-Term Memory, and, therefore, to whether it fulfils the Topic or the Focus function within the utterance. Differently from previous contention, the present paper stresses the importance not just of the information status of know per se, but also of that of the complement clause.

English Sentential Subject Extraposition: Toward a ‘How Far' and ‘Why' View

English sentential subject extraposition is a marked feature, but it is quite a systematic structure. This study aims to provide an extraposition occurrence environment and a plausible trigger for the extraposition of a sentential subject. To this end, we first identify a total of 414 examples of COCA corpus, and then discuss their predicates as well as sentential types. An adjectival predicate (52.2%) is frequently employed without a strict semantic restriction, whereas that-clause (55.8%) and to-infinitival clause (35.5%) are mostly extraposed at the sentence-final position. From this corpus data, we suggest that the extraposition occurs across no more than the first complement of a head verb if and only if the complement is not a clause. In addition, the extraposition is assumed to be triggered in order to maximize focus effect (i.e., degree of pitch increase) rather than its grammatical weight, information structure, or BNFC constraint. The essence of the extraposition can be interpreted without solely grounds of the complex syntactic constituents or the discourse-new/old structures. In other words, in order to achieve a speaker's desired result to put an emphasis on a main predicate, he or she employs the rise of pitch on the main predicate, thereby extraposing a sentential subject.

Structurally constrained controller synthesis for general proper plants with application to vehicle platooning

ABSTRACTThis paper considers the problem of synthesising a static output feedback (SOF) subject to arbitrary information structure constraints; in particular, the plants can be non-strictly proper. In such a case, the existing methods are hardly applicable except few special cases. A general approach that significantly differs from the existing methods is proposed that is able to deal with the most general case with the feature that both finite-frequency and full-frequency H-infinity performance specifications can be addressed in a unified manner. Sufficient solvability conditions are derived in terms of a set of finite-frequency positive real and strictly positive real conditions of linear matrix inequalities (LMIs) form. Some frequency-dependent matrices are introduced into the design with the merit of making the conditions less restrictive. Several numerical examples are given that demonstrate the efficacy of the proposed approach, including applications to vehicle platooning.

Expression of information structure in West Slavic: Modeling the impact of prosodic and word-order factors

The received wisdom is that word-order alternations in Slavic languages arise as a direct consequence of word-order-related information-structure constraints such as ‘Place given expressions before new ones’. In this article, we compare the word-order hypothesis with a competing one, according to which word-order alternations arise as a consequence of a prosodic constraint: ‘Avoid stress on given expressions’. Based on novel experimental and modeling data, we conclude that the prosodic hypothesis is more adequate than the word-order hypothesis. Yet we also show that combining the strengths of both hypotheses provides the best fit for the data. Methodologically, our article is based on gradient acceptability judgments and multiple regression, which allows us to evaluate whether violations of generalizations like ‘Given precedes new’ or ‘Given lacks stress’ lead to a consistent decrease in acceptability and to quantify the size of their respective effects. Focusing on the empirical adequacy of such generalizations rather than on specific theoretical implementations also makes it possible to bridge the gap between different linguistic traditions and to directly compare predictions emerging from formal and functional approaches.

Optimization and static output-feedback control for half-car active suspensions with constrained information

In this paper, the static output-feedback control problem of active suspension systems with information structure constraints is investigated. In order to simultaneously improve the ride comfort and stability, a half car model is used. Other constraints such as suspension deflection, actuator saturation, and controller constrained information are also considered. A novel static output-feedback design method based on the variable substitution is employed in the controller design. A single-step linear matrix inequality (LMI) optimization problem is solved to derive the initial feasible solution with a sparsity constraint. The initial infeasibility issue of the static output-feedback is resolved by using state-feedback information. Specifically, an optimization algorithm is proposed to search for less conservative results based on the feasible controller gain matrix. Finally, the validity of the designed controller for different road profiles is illustrated through numerical examples. The simulation results indicate that the optimized static output-feedback controller can achieve better suspension performances when compared with the feasible static output-feedback controller.

Decentralized overlapping tracking control

In this paper, a new methodology for decentralized overlapping tracking control of complex or large-scale systems is proposed. The methodology is demonstrated in the case of multiple systems moving in a plane. Starting from the given information structure constraints, the expansion/contraction paradigm based on the restriction conditions is applied. The local design provides tracking controllers for the extracted subsystems; contraction is done according to the inclusion principle and results in a stable controller provided the system graph has a directed spanning tree. A specific methodology based on sequential LQ optimization is proposed for local controller design.

Optimal robust decentralized control design for fuzzy complex systems

We consider a decentralized control design for a class of fuzzy complex systems. This system contains uncertainty, consists of multiple subsystems, and faces information structure constraints. The uncertainty is represented by an uncertain bound, which is described by a fuzzy membership function. The control scheme is decentralized. In addition, it is robust and optimal: while it guarantees certain performance regardless of the uncertainty, it also minimizes a performance index. With regard to the minimization phase of the design, the solution is shown to be existent and unique.

Information structure constraints and complex NP islands in Chinese

This paper presents an analysis of the complex NP island effects in Chinese. I follow Ginzburg & Sag (2000)'s analysis of in situ wh-interrogative construction and propose that feature percolation from the non-head clause daughter to the head daughter is required for a proper treatment of in situ wh-relative. A semantic analysis of the idiosyncrasy of weishenme 'why' reveals that a definite reading is forced for a wh-relative when weishenme stays in situ. This requirement causes feature percolation into relative head to fail. In this way I show that island effects in Chinese can be independently ruled out in the grammar as a case of contradiction.

Resilient decentralized filtering of interconnected discrete-time systems

The objective of this paper is to propose new tools for robust and resilient filter design of a class of interconnected discrete-time systems with uncertain function of nonlinear perturbations by exploiting the decentralized information structure constraint. We seek to establish complete LMI-based procedures for linear filtering by basing all the computations at the subsystem level. The robustness property of filter design is assessed in terms of ℓ∞ performance while the resilience property is evaluated in face of additive gain variations that reflect the imprecision in filter implementation. By a suitable convex analysis, it is shown that both design problems can be formulated as convex minimization problem over linear matrix inequalities (LMIs). Numerical examples are provided to illustrate the effectiveness of the developed design methods.

Coordinated Control for a Group of Interconnected Pairwise Subsystems

The implementation of pairwise decomposition is discussed on an interconnected system with uncertainties. Under the concept of system inclusion, two systems with the same expanded system achieved by the same expand transformation are considered as approximations. It is proven that a coordinated controller can be found to stabilize both the two systems. This controller is contracted from the coordinated controller of expanded system, with each pairwise subsystem having information structure constraint taken into consideration. At last, this controller design process is applied on a four-area power system treated as a group of subsystems with information structure constraints.

Static output-feedback control under information structure constraints

An important challenge in the static output-feedback control context is to provide an isolated gain matrix possessing a zero–nonzero structure, mainly in problems presenting information structure constraints. Although some previous works have contributed some relevant results to this issue, a fully satisfactory solution has not yet been achieved up to now. In this note, by using a Linear Matrix Inequality approach and based on previous results given in the literature, we present an efficient methodology which permits us to obtain an isolated static output-feedback gain matrix having, simultaneously, a zero–nonzero structure imposed a priori.

Information structure constraints on object marking in Manyika

Object markers in Bantu languages have commonly been analysed as either agreement morphemes or incorporated pronouns. This paper documents a number of empirical facts concerning object marking in Manyika (chiShona), showing that the distribution of object marking does not fit the predictions of either the agreement or pronominalisation accounts. Specifically, we show that doubling of the object marker and the noun phrase object is in principle possible, but is constrained in a number of instances by the information structure status of the object. This paper therefore makes two distinct claims: first, Manyika object markers (and perhaps other object markers in Bantu languages) ought to be analysed under the rubric of clitics, rather than as agreement morphemes or incorporated pronouns. Second, we claim that the constraints on clitic-doubling are not dependably syntactic in nature; instead, co-occurrence of an object marker and an object is licensed (or not) based on whether the object is in a non-focus domain.

Decentralized static output‐feedback H∞ controller design for buildings under seismic excitation

SUMMARYIn this work, we present a new method in designing static output‐feedback H∞ controllers suitable for vibrational control of buildings under seismic excitation. The method produces a Linear Matrix Inequality (LMI) formulation that allows obtaining static output‐feedback controllers with different information structure constraints by imposing a convenient zero–nonzero structure on the LMI variables. The application of the proposed methodology is illustrated by designing centralized and decentralized velocity‐feedback H∞ controllers to mitigate the seismic response of a five‐story building. Copyright © 2011 John Wiley & Sons, Ltd.