bluuebunny/crossref_metadata_2025_split huggingface dataset:
The relation of children's single word utterances to single word utterances in the input
Authors: Ninio Anat 
Published: February 2009

ABSTRACTThe reported study investigated the relation between children's single-word utterances and maternal single-word utterances expressing similar communicative intents. Twenty-four Hebrew-speaking dyads (the children about 1;6) were videotaped for 30 min in an unstructured session. Single-word utterances were analysed for their communicative intent and the relationship of the expression to the underlying intent was defined in the form of realization rules. Of 17,471 child utterances, 97·0% were realizations that were also used by mothers for expressing the same communicative intent. The most frequently modelled rule for an intent had the highest chance of being adopted by children, and the probability sharply decreased for the relatively less frequently modelled rules. The results suggest that children's single-word utterances are similar to, and probably learned from, single-word utterances of caretakers expressing the same specific communicative intents.
The optional subject phenomenon in young children's English: a case study
Authors: Ingham Richard 
Published: February 2009

ABSTRACTRecent treatments of the optionality of sentence subjects in young-children's English have sought to link this phenomenon, and its eventual demise, to the development of the child's verb inflection system or to a parameter-resetting within the INFL (‘inflection’) constituent of the child's grammar. It is claimed that subject optionality disappears when these developments occur. The case-study reported here investigated the productive language of an English child between 2;5 and 3;0. It found that subjects were no longer optional at a stage when none of the reflexes of INFL claimed in the literature to be associated with the disappearance of subject optionality had yet been acquired. The possibility that subjects were present only when communicatively required was rejected. The frequency of subject realization of a Japanese child aged 3;0 was used to provide a measure of expected realization when subjects are not grammatically required. It is concluded that subject obligatoriness in English may be acquired as a characteristic of the language sui generis, independently of developments elsewhere in the child's emerging grammar.
Maternal speech to three-month-old infants in the United States and Japan
Authors: Toda Suero , Fogel Alan , Kawai Masatoshi 
Published: February 2009

ABSTRACTAn American-Japanese comparison of maternal speech to 3-month-old infants is presented. Mother-infant dyads were videotaped in the laboratory, and the maternal speech was analysed by function and syntactic form. US mothers were more information-oriented than were Japanese mothers; they also used more question forms, especiallyyes/noquestions. Japanese mothers were affect-oriented, and they used more nonsense, onomatopoeic sounds, baby talk, and babies' names. The differences between countries in maternal speech addressed to 3-month-olds appear to reflect characteristic culture-specific communicative styles as well as beliefs and values related to childrearing.
The early development of perfect aspect: adverbial, verbal and contextual specification
Authors: Youssef Valerie 
Published: February 2009

ABSTRACTIn a longitudinal study concerned to assess Verb Phrase (VP) development in three Trinidadian children, adverbials were found to be crucial in delineating specific areas of semantic intent, and to develop early (between ages 2;3 and 3;0). The children were studied over a two-year period, from the onset of morphological marking on the verb, and were recorded two to four hours per month, in their home environments, with a variety of addressees. Two of the children were exposed to, and acquired, both TC and SE verb categories and the third, TC, but the existence of TC past-completive zero 0 as a prominent verbal marker in all their systems made for reliance on adverbial and extralinguistic context in delineating meaning intentions at an early stage;the use which they made of adverbial specification, in particular for marking perfect aspect, indicates how useful these elements may be for precise specification of the development of tense-aspect categories. When they are considered alongside other VP features a clearer overall assessment of tense–aspect development may be made.
Syntactic distinctions in child language
Authors: Bloom Paul 
Published: February 2009

ABSTRACTThis paper presents a study of young children's understanding of a constraint on English word order, which is that pronouns and proper names cannot be modified by prenominai adjectives. For adults, this is a syntactic constraint: adjectives can only precede nouns, and pronouns and proper names are lexical Noun Phrases (NPs). In two analyses, the spontaneous speech of 14 one- and two-year-old children was studied. These analyses show that even in children's very first word combinations, they almost never say things like big Fred or big he. Some non-syntactic theories of this phenomenon are discussed and found to have serious descriptive problems, supporting the claim that children understand knowledge of word order through rules that order abstract linguistic categories. A theory is proposed as to how children could use semantic information to draw the noun/NP distinction and to acquire this restriction on English word order.
On the pragmatics of contrast
Authors: Clark Eve V. 
Published: February 2009

ABSTRACTIn this paper, I review properties and consequences of the PRINCIPLE OF CONTRAST. This principle, which I have argued from the beginning has a pragmatic basis, captures facts about the inferences speakers and addressees make for both conventional and novel words. Along with a PRINCIPLE OF CONVENTIONALITY, it accounts for the pre-emption of novel words by well-established ones. And it holds just as much for morphology as it does for words and larger expressions. In short, Contrast has the major properties Gathercole (1989) proposed as characteristic of her alternative to Contrast.
The Child Language Data Exchange System: an update
Authors: MacWhinney Brian , Snow Catherine 
Published: February 2009

ABSTRACTIn a previous issue of thisJournal, MacWhinney & Snow (1985) laid out the basic sketch for an international system for exchanging and analysing child language transcript data. This system – the Child Language Data Exchange System (CHILDES) – has developed three major tools for child language research: (1) the CHILDES database of transcripts, (2) the CHAT system for transcribing and coding data, and (3) the CLAN programs for analysing CHAT files. Here we sketch out the current shape of these three major tools and the organizational form of the CHILDES system. A forthcoming book (MacWhinney, in press) documents these tools in detail.
The gliding motion of a bacterium: Flexibacter strain BH3
Authors: O'Brien R. W. 
Published: February 2009

AbstractThe flexibacters are a form of gliding bacteria which are often found on the surfaces of solid bodies in fresh and salt water. An individual organism lacks motility in the bulk aqueous phase but glides over a solid surface with its rod-like body aligned with and nearly touching the surface. It has been suggested that this gliding motion in Flexibacter strain BH3 may be caused by waves moving down the outer surface of the rod-shaped cell [2]. This paper is concerned with the fluid mechanical aspects of this form of propulsion.Formulae for the velocity of the organism and for the power dissipation are obtained by using a lubrication theory analysis in the small gap between the bacterium and the wall. It is found that for any progressive waveform there is an optimum distance from the wall at which the flexibacter may maximize its speed for a given power output. Assuming that the flexibacter sits at this optimum distance and taking the waveform to be sinusoidal we calculate the power required for the flexibacter to move at the maximum observed speed. It is found that this power requirement represents only a small fraction of the power available to the cell.
Effects of iron on a toroidal conductor
Authors: Caldwell James 
Published: February 2009

AbstractThe effects of iron on the uniformity of the field produced by a current-carrying axisymmetric conductor are considered. Using a perturbation analysis a simple analytic expression is obtained which describes the field close to the axis of symmetry. A Fourier series approach is also used to provide an analytical solution to the problem and the accuracy of the perturbation method is estimated by comparing results.
Applications of the Lie theory of extended groups in Hamiltonian mechanics: the oscillator and the Kepler problem
Authors: Leach P. G. L. 
Published: February 2009

AbstractThe method of the Lie theory of extended groups has recently been formulated for Hamiltonian mechanics in a manner which is consistent with the results obtained using the Newtonian equation of motion. Here the method is applied to the three-dimensional time-independent harmonic oscillator and to the classical Kepler problem. The expected constants of motion are obtained. Previously unobserved relations between generators and invariants are also noticed.
Extended optima and equilibria for continuous games
Authors: Gates D. J. , Westcott M. 
Published: February 2009

AbstractThe new optima and equilibria discussed in the preceding two papers are compared with the results of bargaining experiments between two and three players performed by Fouraker and Siegel. Experiments where players have complete or incomplete information are considered. There is clear evidence that the new optima are operating, and that traditional optima–Cournot, Pareto and competitive (threat)–are less satisfactory in explaining the course of the whole bargaining process.
Extrapolation of sequences using a generalized epsilon-algorithm
Authors: Barber Michael N. , Hamer C. J. 
Published: February 2009

AbstractThe problem of estimating the limit f∞ of a sequence fn converging as fn − f∞ = O(n−λ) as n → ∞, where λ > 0, is discussed. Using the generalization of the ε-algorithm proposed recently by Vanden Broeck and Schwartz, an acceleration scheme is developed. The method is illustrated on several test sequences and compared to other acceleration procedures.
Linearized planing-surface theory with surface tension. Part I: Smooth detachment
Authors: Tuck E. O. 
Published: February 2009

AbstractIn the absence of surface tension, the problem of determining a travelling surface pressure distribution that displaces a portion of the free surface in a prescribed manner has been solved by several authors, and this “planing-surface” problem is reasonably well understood. The effect of inclusion of surface tension is to change, in a dramatic way, the singularity in the integral equation that describes the problem. It is now necessary in general to allow for isolated impulsive pressure, as well as a smooth distribution over the wetted length. Such pressure points generate jump discontinuities in free-surface slope. Numerical results are obtained here for a class of problems in which there is a single impulse located at the leading edge of the planing surface and detachment with continuous slope at the trailing edge. These results do not appear to approach the classical results in the limit as the surface tension approaches zero, a paradox that is resolved in Part II, which follows.
A generalization of Rapp's formula
Authors: Pearce C. E. M. 
Published: February 2009

AbstractThe Rapp formula of teletraffic dimensioning is generalized to admit an arbitrary renewal stream of offered traffic. The derivation proceeds from a heavy traffic approximation and provides also an estimate of the order of error involved in the Rapp formula. In principle, the method could be used to seek convenient higher order approximations.Our equations give an incidental theoretical substantiation of an empirical result relating to marginal occupancy found recently by Potter.
A note on the impulse due to a vapour bubble near a boundary
Authors: Blake J. R. , Cerone P. 
Published: February 2009

AbstractAn expression for the impluse due to a vapour (cavitation) bubble is obtained in terms of an integral over a nearby boundary. Examples for a point source near a free surface, rigid boundary, inertial boundary and a fluid of different density are considered. It appears that the sign of the impluse determines the direction a cavitation bubble will migrate and the direction of the high speed liquid jet during the collapse phase. The theory may explain recent observations on buoyant bubbles near an interface between two fluids of different densities.
The asymptotic behaviour due to a piecewise time dependent net maternity function
Authors: Cerone P. , Tognetti K. P. 
Published: February 2009

AbstractThe long term asymptotic behaviour of a population is evaluated where the age specific fertility behaviour is allowed to change with time. Thus in this article the behaviour of a population is determined with a time dependent net maternity function. It is shown that methods used when the net maternity function was independent of time are still applicable if the change with time is explicit only for the initial population. Further, using the fact that for realistic situations the net maternity function is non-zero over a finite interval α < x < β, it is shown that traditional methods can again be used if the time dependence is associated with ages less than α, the minimum age of childbearing. Recent extensions of Cerone and Keane to include exponential time dependence are utilized and models are presented which are piecewise defined, allowing general and exponential time dependence for the parent and new-born populations respectively. The Sharpe-Lotka single sex determinstic population model is used as the basis for the analysis.
Welfare optimization and multinational monopolies
Authors: Russell A. M. , Martini C. A. , Rickard J. A. 
Published: February 2009

AbstractThis paper examines the role of import tariffs and consumption taxes when a product is supplied to a domestic market by a foreign monopoly via a subsidiary. It is assumed that there is no competition in the domestic market from internal suppliers. The home country is able to levy a profits tax on the subsidiary. The objective of our analysis is to determine the mix of tariff and consumption tax which simultaneously maximizes national welfare. We show that national welfare does not have an internal maximum, but attains its maximum on a boundary of the consumption tax–tariff parameter space. Furthermore, the optimal value of national welfare increases as the tariff decreases and the consumption tax increases. The results obtained generalize the results of an earlier paper in which national welfare was maximized with respect to either a tariff or consumption tax, but not both.
The construction of zonal models of dispersion in channels via matched centre manifolds
Authors: Watt S. D. , Roberts A. J. 
Published: February 2009

AbstractTaylor's model of dispersion simply describes the long-term spread of material along a pipe, channel or river. However, often we need multi-mode models to resolve finer details in space and time. Here we construct zonal models of dispersion via the new principle of matching their long-term evolution with that of the original problem. Using centre manifold techniques this is done straightforwardly and systematically. Furthermore, this approach provides correct initial and boundary conditions for the zonal models. We expect the proposed principle of matched centre manifold evolution to be useful in a wide range of modelling problems.
A maximum principle for optimal control for a class of controlled systems
Authors: Xu Wensheng 
Published: February 2009

AbstractApplying Ekeland's variational principle in this paper, we obtain a maximum principle for optimal control for a class of two-point boundary value controlled systems. The control domain need not be convex. For a special case, that is the so called LQ-type problem, we obtain the optimal control in the closed loop form and a corresponding Riccati type differential equation.
Optimal control computation to account for eccentric movement
Authors: Jennings L. S. , Wong K. H. , Teo K. L. 
Published: February 2009

AbstractA class of optimal control models which involve different weightings in the integrand of the objective function is considered. The motivation for considering this class of problems is that this type of objective function is used to account for eccentric movement in biomechanical models. The computation of these optimal control problems using control parametrization directly is difficult, firstly because of ill-conditioning, and secondly because the objective function is not differentiable. A method for smoothing the integrand is presented with convergence results. An example is computed which shows favourable computational improvements.
A comparative study of smoothing approximations
Authors: Yang X. Q. 
Published: February 2009

AbstractIt is known that many optimization problems can be reformulated as composite optimization problems. In this paper error analyses are provided for two kinds of smoothing approximation methods of a unconstrained composite nondifferentiable optimization problem. Computational results are presented for nondifferentiable optimization problems by using these smoothing approximation methods. Comparisons are made among these methods.
Propagation relations for solutions of some higher order cauchy problems
Authors: Bragg L. R. 
Published: February 2009

AbstractThe Huygens' property is exploited to study propagation relations for solutions of certain types of linear higher order Cauchy problems. Motivated by the solution properties of the abstract wave problem, addition formulas are developed for the solution operators of these problems. The application of these alternative forms of the solution operators to data leads to connecting operator relations between distinct solutions of the problems at different times. We examine this solution behaviour for both analytic and abstract Cauchy problems. A basic algorithm for constructing addition formulas for solutions of ordinary differential equations is included.
Withdrawal of layered fluid through a line sink in a porous medium
Authors: Zhang H. , Hocking G. C. 
Published: February 2009

AbstractThe flow induced when fluid is withdrawn through a line sink from a layered fluid in a homogeneous, vertically confined porous medium is studied. A nonlinear integral equation is derived and solved numerically. For a given sink location, the shape of the interface can be determined for various values of the flow rate. The results are compared with exact solutions obtained using hodograph methods in a special case. It is found that the cusped and coning shapes of the interface can be accurately obtained for the sink situated at different depths in the fluid and the volume of flow into the sink per unit of time.
Small reynolds number flow between eccentric rotating cylinders with a permeable sleeve
Authors: Hird L. D. , Siew P. F. 
Published: February 2009

AbstractTwo eccentric rotating cylinders together with a permeable membrane surrounding the inner cylinder are used to model the flow around a modified viscometer. A perturbation method is used to solve for the flow between the membrane and the outer cylinder; the flow between the inner rotor and the membrane is assumed to be governed by Stoke's equation, and the two flow regimes are coupled by the through-flow across the membrane. For moderate values of Reynolds number and eccentricity, the permeability of the membrane plays a negligible role, and the flow through the membrane is found to be eccentricity dependent. High eccentricities result in the formation of eddies which, upon increasing the Reynolds number, move in a direction opposite to that of the rotation of the outer bowl.
Fast solvers for finite difference approximations for the stokes and navier-stokes equations
Authors: Shin Dongho , Strikwerda John C. 
Published: February 2009

AbstractWe consider several methods for solving the linear equations arising from finite difference discretizations of the Stokes equations. The two best methods, one presented here for the first time, apparently, and a second, presented by Bramble and Pasciak, are shown to have computational effort that grows slowly with the number of grid points. The methods work with second-order accurate discretizations. Computational results are shown for both the Stokes equations and incompressible Navier-Stokes equations at low Reynolds number.
Global strong solutions of equations of magnetohydrodynamic type
Authors: Rojas-Medar Marko A. , Boldrini José Luiz 
Published: February 2009

AbstractBy using the spectral Galerkin method, we prove a result on the global existence in time of strong solutions for a system of equations of magnetohydrodynamic type. Several estimates for the solution and their approximations are given. These estimates can be used in the derivation of error bounds for the approximate solutions.
Formation of singularities in a stratified fluid in the presence of a critical level
Authors: Dostovalova Anna S. , Simakov Sergey T. 
Published: February 2009

AbstractThe paper is concerned with formation of singularities in a density stratified fluid subject to a monochromatic point source of frequency σ. The frequency of the source is assumed to be such that the steady-oscillation equation is hyperbolic in the neighbourhood of the source and degenerates at a critical level. We obtain asymptotic formulae demonstrating how the solution diverges as t → ∞ on the characteristic surface emanating from the source. It is shown that, at points of the surface that belong to the critical level, the solution behaves as t⅔ exp {i(σt + π/2)} as t → ∞, whereas its large time behaviour at the other points of the surface is given by t½ exp {i(σt + π/2 ± π/4)}.
Optimal driving strategies for a train on a track with continuously varying gradient
Authors: Howlett P. G. , Cheng J. 
Published: February 2009

AbstractThis paper derives key equations for the determination of optimal control strategies in an important engineering application. A train travels from one station to the next along a track with continuously varying gradient. The journey must be completed within a given time and it is desirable to minimise fuel consumption. We assume that only certain discrete throttle settings are possible and that each setting determines a constant rate of fuel supply. This assumption is based on the control mechanism for a typical diesel-electric locomotive. For each setting the power developed by the locomotive is directly proportional to the rate of fuel supply. We assume a single level of braking acceleration. For each fixed finite sequence of control settings we show that fuel consumption is minimised only if the settings are changed when certain key equations are satisfied. The strategy determined by these equations is called a strategy of optimal type. We show that the equations can be derived using an intuitive limit procedure applied to corresponding equations obtained by Howlett [9, 10] in the case of a piecewise constant gradient. The equations will also be derived directly by extending the methods used by Howlett. We discuss a basic solution procedure for the key equations and apply the procedure to find a strategy of optimal type in appropriate specific examples.