bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sampling with probabilities proportional to the variable of interest
Authors: Moors J. J. A. , Smeets R. , Boekema F. W. M. 
Published: March 2003

To estimate the mean sojourn time, a sample of Tilburg fair visitors was asked for the duration of their stay on the fair grounds. The longer a visitor's sojourn, the larger his/her probability of being interviewed will be; therefore, longer sojourn times will be overrepresented in the sample. As a consequence, the arithmetic sample mean is not a good estimator.The paper places this problem against a theoretical background. Sampling with unequal probabilities is considered in a general context. The special case that the sampling probabilities are a function of the variable under investigation, is discussed in detail. As a better estimator the harmonic mean of the observations is presented. Most properties of this estimator are difficult to derive analytically, but a suitable variance estimator is derived. The behavior of estimator and variance estimator is studied in a number of quite different examples.
The M/G/∞ Queueing Model for Optimistic Concurrency Control
Authors: Sassen S. A. E. , Van Der Wal J. 
Published: March 2003

The M/G/∞ queue with Optimistic Concurrency Control (OCC) is a model for a special form of parallel transaction processing in a real‐time database. Transactions arrive according to a Poisson process and require some generally distributed execution time. One of the differences with ordinary multi‐ and infinite‐server queueing models is that under OCC the successful completion of one transaction may immediately cause the failure of one or more of the other transactions. This happens if the completing transaction has overwritten a data‐item that is in use by another transaction in progress. As soon as this failure is detected the failed transaction is restarted. So the total service time of a transaction consists of its final successful run and the time spent on unsuccessful runs.In this study we develop an approximation for the distribution of the total service time, and test the approximation against simulation. Although in practice the number of servers is never unlimited, this study provides valuable insight in the asymptotics with respect to the number of servers. The approximation clearly demonstrates the very limited performance gain from an increase of the number of servers.
On the generalized Poisson distribution
Authors: Tuenter H. J. H. 
Published: March 2003

We use Euler's difference lemma to prove that, for θ > 0 and 0 ≤λ < 1, the function Pn defined on the non‐negative integers by P

n
(θ, λ) = [θ(θ + nλ)n−1/n!]e−nλ−θdefines a probability distribution, known as the Generalized Poisson Distribution.
Statistics for the contact process
Authors: Fiocco Marta , Van Zwet Willem R. 
Published: March 2003

A d‐dimensional contact process is a simplified model for the spread of an infection on the lattice Zd. At any given time t≥0, certain sites x∈Zd are infected while the remaining once are healthy. Infected sites recover at constant rate 1, while healthy sites are infected at a rate proportional to the number of infected neighboring sites. The model is parametrized by the proportionality constant λ. If λ is sufficiently small, infection dies out (subcritical process), whereas if λ is sufficiently large infection tends to be permanent (supercritical process).In this paper we study the estimation problem for the parameter λ of the supercritical contact process starting with a single infected site at the origin. Based on an observation of this process at a single time t, we obtain an estimator for the parameter λ which is consistent and asymptotically normal as t→∞
Some problems in actuarial finance involving sums of dependent risks
Authors: Goovaerts M. J. , Kaas R. 
Published: March 2003

A trend in actuarial finance is to combine technical risk with interest risk. If Yt, t= 1, 2,… denotes the time–value of money (discount factors at time t) and Xt the stochastic payments to be made at time t, the random variable of interest is often the scalar product of these two random vectors V=ΣXt Yt. The vectors X? and Y? are supposed to be independent, although in general they have dependent components. The current insurance practice based on the law of large numbers disregards the stochastic financial aspects of insurance. On the other hand, introduction of the variables Y1,Y2, … to describe the financial aspects necessitates estimation or knowledge of their distribution function.We investigate some statistical models for problems of insurance and finance, including Risk Based Capital/Value at Risk, Asset Liability Management, the distribution of annuities, cash flow evaluations (in the framework of pension funds, embedded value of a portfolio, Asian options) and provisions for claims incurred, but not reported (IBNR).
Individual differences, strategic performance and achievement in second language learners of Spanish
Authors: Luja´n‐Ortega Violante , Clark‐Carter David 
Published: March 2003

The study examines whether learners' individual characteristics predict their use of strategies and whether individual differences and strategy use predict achievements in formal language examinations.Participants were post A‐Level learners of Spanish in their first year at University. They were formally assessed for their competence in the language in various tasks. They also performed oral tasks in which they encountered problems due to insufficient linguistic resources, but overcame their deficiencies by using compensatory strategies. Individual differences were assessed through standardised measures of personality/learning style and intelligence. Gender was also noted.Hierarchical multiple regressions were conducted. They revealed that IQ, learning style, and the strategies adopted by the students each explain a substantial and significant amount of variance in assessment. In addition, although not significant, the results suggest that participants' individual differences do predict aspects of their strategy use.
Justification of a Perturbation Approximation of the Klein–Gordon Equation
Authors: Jiang X.‐H. , Wong R. 
Published: March 2003

Consider the nonlinear wave equation utt−γ2uxx+f(u) = 0with the initial conditions u(x,0) = εφ(x), ut(x,0) = εψ(x),where f(u) is either of the form f(u)=c2u−σu2s+1, s=1, 2,…, or an odd smooth function with f′(0)>0 and |f′(u)|≤C02.The initial data ϕ(x)∈C2 and ψ(x)∈C1 are odd periodic functions that have the same period. We establish the global existence and uniqueness of the solution u(x, t; ɛ), and prove its boundedness in x∈R and t>0 for all sufficiently small ɛ>0. Furthermore, we show that the error between the solution u(x, t; ɛ) and the leading term approximation obtained by the multiple scale method is of the order ɛ3 uniformly for x∈R and 0≤t≤T/ɛ2, as long as ɛ is sufficiently small, T being an arbitrary positive number.
Spectral Residues of Second‐order Differential Equations: A New Method for Summation Identities and Inversion Formulas
Authors: Milson R. 
Published: March 2003

This article deals with differential equations with spectral parameter from the point of view of formal power series.The treatment does not make use of the notion of eigenvalue, but introduces a new idea: the spectral residue.The article focuses on second‐order, self‐adjoint problems. In such a setting, every potential function determines a sequence of spectral residues. This correspondence is invertible and gives rise to a combinatorial inversion formula. Other interesting combinatorial consequences are obtained by considering spectral residues of exactly solvable potentials of one‐dimensional quantum mechanics.It is also shown that the Darboux transformation of one‐dimensional potentials corresponds to a simple negation of the corresponding spectral residues. This fact leads to another combinatorial inversion formula. Finally, there is a brief discussion of applications. The topics considered are enumeration problems and integrable systems.
V‐Positions and the Middle Field in West Flemish
Authors: Haegeman Liliane 
Published: March 2003

The distribution of the finite verb in the West Flemish Infinitivus Pro Participio construction provides evidence for embedded V‐movement in the lower Middle Field of the West Germanic SOV languages. Two functional heads are postulated in the lower Middle Field, F1 (which checks Tense and Negation) and F2 (which checks aspect). FP1 dominates FP2. Finite verbs may remain in F2, or move to F1 (depending on feature strength), infinitives remain in F2. The analysis accounts for the finite/non‐finite asymmetery in the distribution of the negative head en in West Flemish and provides indirect support for Kayne’s antisymmetry hyposthesis.West Flemish bare infinitival complements remain to the right of F2, IPP complements occupy the specifier position of FP2, and past participles incorporate to F1. A parallelism between DP positions and the positions of non‐finite verbal complements is explored in the final part of the paper.
Unordered Merge and its Linearization
Authors: Yang Charles D. 
Published: March 2003

In the Minimalist Program (Chomsky 1995), Merge is a set operation that imposes no intrinsic ordering among its members. However, syntactic structures are linearized into strings of words at PF. This paper proposes that in order for a Merger set to be linearized, its members must be either hierarchically displaced or morphologically fused into a single terminal node.The empirical study focuses on the structure of DP and its linearization in various constructions. It is shown that the Definiteness Effect (DE) can be attributed to the failure to linearize the DP in unaccusatives. The systematic lack of the DE in some languages (Arabic, Hebrew, and Romanian), unexpected in previous analyses, is due to the morphological N‐to‐D raising (fusion), therefore satisfying the linearization condition. Furthermore, cross‐linguistic evidence is given to show that D can be attracted out of DP for feature checking, rendering transitive DP arguments well‐formed.
The Arts Of Deception: Verbal Performances By The Ra¯ute Of Nepal
Authors: Fortier Jana 
Published: March 2003

A small population of Tibeto‐Burman‐speaking hunter‐gatherers, the Ra¯ute avoid intercultural communication with surrounding Nepa¯li‐speaking agriculturalists except during barter sessions. During these intercultural interactions, Ra¯ute often charm their trading partners with Nepa¯li verbal art, including recitation of rhymes, songs, and blessings. In this article I suggest that Ra¯ute perform verbal art in order to draw attention away from their radically different lifestyle and as a way of resisting the hegemonic process of Hinduization. The article details Ra¯ute oral performance as a strategy of verbal indirection, focusing on the context and framing of rhyming proverbs as a means of camouflaging Ra¯ute people’s actual cultural practices. ba¯darko sa¯pet.o Ra¯uteko dha¯mi la¯i, kheti cha¯ina pa¯ti cha¯ina, ke kha¯nu ha¯mi la¯i? ‘The monkey’s thigh is the shaman’s meat,Having no farmland, what shall we eat?’Gogane Ra¯ute
Output Effects of Transport Infrastructure: The Netherlands, 1853–1913
Authors: Groote Peter , Jacobs Jan , Sturm Jan‐Egbert 
Published: March 2003

In this paper we put to trial the alleged role of investment in transport and communications infrastructure in economic growth in the Netherlands in the second half of the nineteenth century. To do so, we combine a new data set with data‐oriented econometric techniques. Testing of the main hypothesis by applying Granger's concept of causation in a vector auto‐regression model reveals that the development of infrastructure ‘caused’ Dutch economic growth. In order to investigate the underlying mechanisms, we enhance the basic model with impulse‐response analysis. This leads to a clear response pattern of GDP to a change in transport infrastructure investment. The response of GDP is explained as being induced by three underlying mechanisms:1. Positive forward linkage effects (mainly through reductions in the costs of transport and communications).2. Positive backward linkage effects (mainly through expenditure and income effects).3. Negative transitional dynamics (mainly through changes in the spatial setting of the economy).
Wole Soyinka’s Poetry as Bilingual’s Creativity
Authors: Osakwe Mabel I. 
Published: March 2003

This paper attempts an identification and examination of some of the features that make Wole Soyinka’s poems unmistakably bilingual and bicultural.Four linguistic strategies revealing some features often employed in Yoruba poetic discourse are identified across the poet’s four anthologies to date (1967–89). While drawing attention to the poet’s manner of incorporating these features into his poetry of English L2 (EL2) expression, the paper also focuses on stylistic translation; an imitation of Yoruba poetic forms. Consequently the stylistic imitation of two Yoruba forms: Owe and Ofo are also explored across the four anthologies.The manner of these usages by the poet are examined vis‐a`‐vis their stylistic effect in the new L2 linguistic and extra linguistic environment.
“Homogeneity” and Constitutional Democracy: Coping with Identity Conflicts through Group Rights
Authors: Offe Claus 
Published: March 2003

In this article I explore some ancient issues of political theory in the light of some contemporary social and cultural issues. After developing a check list of the virtues and vulnerabilities of constitutional democracy (Section I), I go on to discuss some types and symptoms of difference, conflict, fragmentation and heterogeneity (Section II). I then proceed to a critical review of a particular set of strategies and institutional solutions—political group rights—that are often thought promising devices for strengthening the virtues and overcoming the vulnerabilities of the constitutional democratic form of regime (Section III).Much of the contemporary philosophical and political discussion of these issues is enchanted by the post‐modern spirit of “multiculturalism,”“diversity” and “identity.” It tends to neglect issues of citizenship and social justice. It also tends to fixate on North American examples, neglecting some of the less benign West European and, in particular, Central East European varieties of identity politics. The discussion here, while mostly raising questions rather than claiming to provide definitive answers, nevertheless tries to overcome some of these biases.
“For God Distinguishes the People of Earth as in Heaven”: Hildegard of Bingen’s Social Ideas
Authors: Flanagan Sabina 
Published: March 2003

Despite the massive increase in scholarship dealing with various aspects of the work of Hildegard of Bingen over the last decade, her social ideas have been comparatively neglected. This is not surprising since Hildegard made few direct pronouncements on social relations and when she did, most famously in her letter to Tenxwind of Andernach, she appears to be defending an elitist notion of hereditary privilege against the more egalitarian views of her correspondent.This paper seeks to identify and describe Hildegard’s social ideas by examining her direct and indirect statements on the subject and comparing her notions about the division of society with those of her contemporaries. The idea that Hildegard’s social thought was predicated on a strict division between the free and unfree, par‐ticularly the free and non‐free nobility (Edelfrei and ministeriales), a classification peculiar to twelfth‐century Germany, is examined in the light of these findings. I argue that Hildegard’s views are more complicated than a reading of the Tenxwind letter would suggest and that her understanding allows for a more nuanced view of society than that of her contemporaries. It is also suggested that Hildegard’s views reflect a real grasp of the power relations operating in the world around her and that her practice is, in turn, founded upon this understanding.
Schema effects in EFL reading comprehension
Authors: Bensoussan Marsha 
Published: March 2003

Schemata are known to play an important a role in reading comprehension. Comprehension is seen as the interaction between top‐down processing from activated schemata and bottom‐up processing from concepts expressed by the text. If readers activate an inappropriate schema, they may miss the meaning of the text. The present study examines the effects of faulty schemata on reading comprehension.At the end of an advanced English reading course at Haifa University, a test of reading comprehension was administered to 125 students. One section of the test contained an advanced level text about love and marriage, a text close to the personal experience of the examinees. Using dictionaries, students translated expressions and sentences and answered short‐answer comprehension questions in English. Results indicated that 23% of the wrong answers to the comprehension questions were driven by schemata which differed substantially from the actual content of the text.
Is it Cash that the Deprived are Short of?
Authors: Davies H. , Joshi H. , Clarke L. 
Published: March 2003

Summary
In using census data, a range of indicators is commonly used to indicate deprivation. This paper examines the validity of these indicators by exploring how well they predict income in surveys (the Family Expenditure Surveys of 1983 and 1990 and the General Household Survey of 1984) which also collect income data. A reasonably parsimonious set of seven socioeconomic variables (as well as controls for age, sex and region) explains about 40% of the variation in log-income. Our results provide a set of weights for a deprivation index and offer no support for the practice of assigning equal weights to the indicators. A census-based proxy would miss a sizable minority of the actual poor and misclassify some with higher incomes. A majority of the ‘deprived’ are poor by a cash yardstick, but some are not.
Statistical Issues in Developing Indicators of Sustainable Development
Authors: Custance J. , Hillier H. 
Published: March 2003

Summary
This paper describes the background to the development of a new official set of national indicators of sustainable development—one of the first in the world to be published. The paper discusses the role of statisticians in helping to define sustainable development, and the problems of monitoring and reporting progress. The Minister of State for the Environment has announced his ambition of developing a very small set of headline indicators. This paper is intended to help to stimulate the debate over what they should be.
Working Time in Great Britain, 1975–1994: Evidence from the New Earnings Survey Panel Data
Authors: Bell D. N. F. , Hart R. A. 
Published: March 2003

Summary
Using individual-based panel data from the New Earnings Survey, this paper provides a detailed analysis of the working time behaviour of British full-time male and female workers as well as part-time female workers. We investigate the following: male–female differences in basic and overtime working patterns; extensive overtime working; age-related patterns of weekly basic and overtime hours; the effects of collective bargaining on hours of work; industrial, public–private sector and occupational breakdowns of basic and total hours. The results for the last three topics are based on estimates from fixed effect regressions with time-varying parameters.
Estimating Driver Crash Risks Based on the Extended Bradley–Terry Model: An Induced Exposure Method
Authors: Li Lel , Kim Karl 
Published: March 2003

Summary
Quantifying driver crash risks has been difficult because the exposure data are often incompatible with crash frequency data. Induced exposure methods provide a promising idea that a relative measurement of driver crash risks can be derived solely from crash frequency data. This paper describes an application of the extended Bradley–Terry model for paired preferences to estimating driver crash risks. We estimate the crash risk for driver groups defined by driver–vehicle characteristics from log-linear models in terms of a set of relative risk scores by using only crash frequency data. Illustrative examples using police-reported crash data from Hawaii are presented.
The Comparison of Designs for Sequential Clinical Trials with Covariate Information
Authors: Atkinson Anthony C. 
Published: March 2003

SummaryThe paper develops methods for the comparison of randomized rules of the biased coin type for the sequential allocation of treatments in a clinical trial. One important characteristic is the loss, which measures the increase in the variance of parameter estimates due to the imbalance caused by randomization. The other important characteristic is the selection bias measuring the probability of correctly guessing which treatment is to be allocated next. The combination of these two measures leads to the elucidation of admissible designs. Simulations provide clear plots of the behaviour of the designs and make it possible to distinguish good designs from those which are less good.
Deprivation, Ill-Health and the Ecological Fallacy
Authors: Lancaster Gillian , Green Mick 
Published: March 2003

SummaryThe use of ecological studies in explaining the relationship between deprivation and ill-health is widespread in many health applications. However, inferences drawn from these studies about individuals are susceptible to serious bias known as the ecological fallacy. Our paper demonstrates the ecological fallacy effect in this context but also shows how it can be considerably reduced by taking into account different population structures at the aggregate level. Two regression analyses of limiting long-term illness are performed, one at the individual level and one at the electoral ward level, using the 1991 UK census sample of anonymized records and the small area statistics. The analyses compare several measures of deprivation including the standard Carstairs index, with the separate variables which make up the indices, to determine their effectiveness in explaining rates of illness. Two of the deprivation scores are constructed using latent variable modelling techniques which enable a score to be generated at the individual level as well as at the ward level. It is shown that, given the right choice of socioeconomic variables and taking into account the age structure of the population, it should be possible to construct a single aggregate deprivation index that will explain most of the variation in rates of illness across the study region.
Bias-calibrated Estimation from Sample Surveys Containing Outliers
Authors: Welsh A. H. , Ronchetti Elvezio 
Published: March 2003

Summary
We discuss the problem of estimating finite population parameters on the basis of a sample containing representative outliers. We clarify the motivation for Chambers's bias-calibrated estimator of the population total and show that bias calibration is a key idea in constructing estimators of finite population parameters. We then link the problem of estimating the population total to distribution function or quantile estimation and explore a methodology based on the use of Chambers's estimator. We also propose methodology based on the use of robust estimates and a bias-calibrated form of the Chambers and Dunstan estimator of the population distribution function. This proposal leads to a bias-calibrated estimator of the population total which is an alternative to that of Chambers. We present a small simulation study to illustrate the utility of these estimators.
On the Statistical Inference of a Machine-generated Autoregressive AR(1) Model
Authors: Stockis Jean-Pierre , Tong Howell 
Published: March 2003

Summary
We have obtained the asymptotic bias and the limiting distribution for the Yule–Walker estimator of the autoregressive parameter under a considerably weaker assumption than that of independence in the noise sequence. Among other things, these suggest robustness of the classical results and throw some light on the use of simulations based on pseudorandom numbers in verifying these results.