bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of Linkage and Association‐Issues on Study Design
Authors: Bickeböller Heike
Published: May 2007

For the identification and description of susceptibility genes for complex diseases using genetic markers there are two basic strategies: genome scans or the investigation of candidate genes. The designs can be quite different for the two approaches and decide, more than in general epidemiology, the methods that can be applied subsequently. Study design, recruitment and sample size are discussed further in the context of the Transmission/Disequilibrium Test, a family‐based simultaneous test for linkage and association.
An Introduction to Coding Theory and the Two‐Part Minimum Description Length Principle
Authors: Lee Thomas C. M.
Published: May 2007

This article provides a tutorial introduction to the so‐called two‐part minimum description length (MDL) principle proposed by Rissanen. This two‐part MDL principle is a powerful methodology for solving many statistical model selection problems. However, it seems that this powerful methodology is only adopted by a small number of statisticians to tackle a small number of problems. One plausible reason for this is that the coding theory results required by the MDL principle are somewhat new to most statisticians, and that there are not many readily accessible articles introducing these results appearing in the statistical literature. The first part of this article is devoted to a discussion of such coding theory results. Then, in the second part of the article, the two‐part MDL principle is introduced and explained. In doing so, only those coding theory results that are presented in the first part of the article are used. Finally, the applicability of the two‐part MDL principle is demonstrated by applying it to tackle four different statistical problems.
Competitive On‐line Statistics
Authors: Vovk Volodya
Published: May 2007

A radically new approach to statistical modelling, which combines mathematical techniques of Bayesian statistics with the philosophy of the theory of competitive on‐line algorithms, has arisen over the last decade in computer science (to a large degree, under the influence of Dawid's prequential statistics). In this approach, which we call “competitive on‐line statistics”, it is not assumed that data are generated by some stochastic mechanism; the bounds derived for the performance of competitive on‐line statistical procedures areguaranteedto hold (and not just hold with high probability or on the average). This paper reviews some results in this area; the new material in it includes the proofs for the performance of the Aggregating Algorithm in the problem of linear regression with square loss.
A Bayesian Model for Estimating Census Undercount, Taking Emigration Data from Foreign Censuses*
Authors: Redfern Philip
Published: May 2007

The new method of measuring net undercount in a census of population is a variant of demographic analysis and is founded in the belief that the most reliable counts of people are the counts of births and deaths. It has been applied to the 1991 census of England and Wales (E&W). The method has two distinctive features. The first is that it bases its estimates of numbers of emigrants on figures of persons born here and recorded as residents in the 1990–91 censuses of other countries. The corresponding data on immigrants are taken from our own census. The method does not therefore require the data on migratory flows that are an essential component of conventional demographic analysis. The second feature is the Bayesian approach in which (1) each of 30 uncertain elements in the calculations is given an a priori error distribution and (2) three empirical constraints are imposed on the sex‐age profile of percentage net undercount. This, in conjunction with a Monte Carlo process, generates an error distribution for net undercount. These merits of the method are offset by the demerit that the calculations must await results from the censuses of the other countries in which substantial numbers of our emigrants reside.
Modeling Clustered Ordered Categorical Data: A Survey
Authors: Agresti Alan , Natarajan Ranjini
Published: May 2007

This article surveys various strategies for modeling ordered categorical (ordinal) response variables when the data have some type of clustering, extending a similar survey for binary data by Pendergast, Gange, Newton, Lindstrom, Palta & Fisher (1996). An important special case is when repeated measurement occurs at various occasions for each subject, such as in longitudinal studies. A much greater variety of models and fitting methods are available than when a similar survey for repeated ordinal response data was prepared a decade ago (Agresti, 1989). The primary emphasis of the review is on two classes of models,marginal modelsfor which effects are averaged over all clusters at particular levels of predictors, andcluster‐specific modelsfor which effects apply at the cluster level. We present the two types of models in the ordinal context, review the literature for each, and discuss connections between them. Then, we summarize some alternative modeling approaches and ways of estimating parameters, including a Bayesian approach. We also discuss applications and areas likely to be popular for future research, such as ways of handling missing data and ways of modeling agreement and evaluating the accuracy of diagnostic tests. Finally, we review the current availability of software for using the methods discussed in this article.
Modelling Overdispersion for Complex Survey Data
Authors: Molina E.A. , Smith T.M.F. , Sugden R.A.
Published: May 2007

The population characteristics observed by selecting a complex sample from a finite identified population are the result of at least two processes: the process which generates the values attached to the units in the finite population, and the process of selecting the sample of units from the population. In this paper we propose that the resulting observations by viewed as the joint realization of both processes. We overcome the inherent difflculty in modelling the joint processes of generation and selection by exploring second moment and other simplifying assumptions. We obtain general expressions for the mean and covariance function of the joint processes and show that several overdispersion models discussed in the literature for the analysis of complex surveys are a direct consequence of our formulation, undere particular sampling schemes and population structures.
Idiot's Bayes—Not So Stupid After All?
Authors: Hand David J. , Yu Keming
Published: May 2007

Folklore has it that a very simple supervised classification rule, based on the typically false assumption that the predictor variables are independent, can be highly effective, and often more effective than sophisticated rules. We examine the evidence for this, both empirical, as observed in real data applications, and theoretical, summarising explanations for why this simple rule might be effective.
Statistics by Gender: Measures to Reduce Gender Bias in Agricultural Surveys
Authors: Ayhan H. Öztş
Published: May 2007

Statistics by gender has been the concern of policy makers in the recent past years. The demand on data disaggregated by gender has led the survey statistician to collect data and tabulate statistics by gender. In this paper, some measures will be suggested to avoid and reduce gender bias for data collection and tabulation in agricultural surveys.
Crucial Issues for Statistics in the Next Two Decades
Authors: Fisher Nicholas I.
Published: May 2007

This collection of articles stems from an Invited Paper meeting at the 52nd Session of the ISI in Helsinki, August 1999. The purpose of the session was to explore issues likely to be critical to the long‐term survival of the discipline, if not the profession, of Statistics. The contributors in the session have all made outstanding contributions to both the theory and practice of Statistics, and have also had an ongoing interest in the long‐term development of the subject. Subsequently, they were given the opportunity to elaborate on their contributions, for wider dissemination.
The Role of Statistics in the Data Revolution?
Authors: Friedman Jerome H.
Published: May 2007

The nature of data is rapidly changing. Data sets are becoming increasingly large and complex. Modern methodology for analyzing these new types of data are emerging from the fields of Data Base Managment, Artificial Intelligence, Machine Learning, Pattern Recognition, and Data Visualization. So far Statistics as a field has played a minor role. This paper explores some of the reasons for this, and why statisticians should have an interest in participating in the development of new methods for large and complex data sets.
Future Directions for the Teaching and Learning of Statistics at the Tertiary Level
Authors: Nicholl Des F.
Published: May 2007

Significant advances in, and the resultant impact of, Information Technology (IT) during the last fifteen years has resulted in a much more data based society, a trend that can be expected to continue into the foreseeable future. This phenomenon has had a real impact on the Statistics discipline and will continue to result in changes in both content and course delivery. Major research directions have also evolved during the last ten years directly as a result of advances in IT. The impact of these advances has started to flow into course content, at least for advanced courses. One question which arises relates to what impact will this have on the future training of statisticians, both with respect to course content and mode of delivery. At the tertiary level the last 40 years has seen significant advances in theoretical aspects of the Statistics discipline. Universities have been outstanding at producing scholars with a strong theoretical background but questions have been asked as to whether this has, to some degree, been at the expense of appropriate training of the users of statistics (the ‘tradespersons’).

Future directions in the teaching and learning of Statistics must take into account the impact of IT together with the competing need to produce scholars as well as competent users of statistics to meet the future needs of the market place. For Statistics to survive as a recognizable discipline the need to be able to train statisticians with an ability to communicate is also seen as an areà of crucial importance.

Satisfying the needs of society as well as meeting the needs of the profession are considered as the basic determinants which will derive the future teaching and training of statisticians at the tertiary level and will form the basis of this presentation.
Public Policy Issues as a Route to Statistical Awareness
Authors: Smith Adrian F.M.
Published: May 2007

There appears to be a paradox in the fact that as more and more quantitative information becomes routinely available in a world perceived to be ever more complex, there is less and less direct appreciation of the role and power of statistical thinking. It is suggested that the profession should exploit very real public concerns regarding risk aspects of public policy as a possible pedagogic route to raising statistical awareness.
A Guide to Exact Simulation
Authors: Dimakos Xeni K.
Published: May 2007

Markov Chain Monte Carlo (MCMC) methods are used to sample from complicated multivariate distributions with normalizing constants that may not be computable in practice and from which direct sampling is not feasible. A fundamental problem is to determine convergence of the chains. Propp & Wilson (1996) devised a Markov chain algorithm called Coupling From The Past (CFTP) that solves this problem, as it produces exact samples from the target distribution and determines automatically how long it needs to run. Exact sampling by CFTP and other methods is currently a thriving research topic. This paper gives a review of some of these ideas, with emphasis on the CFTP algorithm. The concepts of coupling and monotone CFTP are introduced, and results on the running time of the algorithm presented. The interruptible method of Fill (1998) and the method of Murdoch & Green (1998) for exact sampling for continuous distributions are presented. Novel simulation experiments are reported for exact sampling from the Ising model in the setting of Bayesian image restoration, and the results are compared to standard MCMC. The results show that CFTP works at least as well as standard MCMC, with convergence monitored by the method of Raftery & Lewis (1992, 1996).
Statistical Issues in fMRI for Brain Imaging
Authors: Lazar Nicole A. , Eddy William F. , Genovese Christopher R. , Welling Joel
Published: May 2007

Functional magnetic resonance imaging is a technique developed in the last decade and used in the fields of cognitive psychology and neuroscience, among others, to study the processes underlying the working of the human brain. In this paper we examine some of the statistical issues in functional magnetic resonance imaging for brain research. We start by giving a brief introduction to the physics of magnetic resonance imaging. Using a psychological experiment as a case study, we then describe questions of design and statistical analysis. The data obtained from functional magnetic resonance imaging studies are of a highly complex nature, displaying both spatial and temporal correlation, as well as high levels of noise from different sources. Given this, the scope for statistics is vast, and is not limited to simple analysis of the data, once collected.
Signal Extraction Problems in Seismology*
Authors: Kitagawa Genshiro , Takanami Tetsuo , Matsumoto Norio
Published: May 2007

The earth's surface is under continuous influence of a variety of natural forces such as the effect of past earthquakes, wave, wind, tide, air pressure, precipitation and a variety of human induced sources. Since it is almost impossible to describe the response to these noise inputs precisely, for automatic processing of seismic data, proper statistical modeling is necessary. In this paper, we describe four specific examples of time series modeling for signal extraction problems related to seismology. Namely, we consider 1) the estimation of the arrival time of a seismic signal, 2) the extraction of small seismic signal from noisy data, 3) the detection of the coseismic effect in groundwater level data contaminated by various effects from air pressure etc., and 4) the estimation of changing spectral characteristic of seismic record.
How to Construct a Random Probability Measure
Authors: Monticino Michael
Published: May 2007

This article presents an overview of several constructive methods for generating random probability measures. Applications of random probability measures include Bayesian statistics, average optimal control problems, average error bounds for numerical equation solving methods, and models for random distributions of mass in space.
Adults' Statistical Literacy: Meanings, Components, Responsibilities
Authors: Gal Iddo
Published: May 2007

Statistical literacy is a key ability expected of citizens in information‐laden societies, and is often touted as an expected outcome of schooling and as a necessary component of adults’numeracy and literacy. Yet, its meaning and building blocks have received little explicit attention. This paper proposes a conceptualization of statistical literacy and describes its key components. Statistical literacy is portrayed as the ability to interpret, critically evaluate, and communicate about statistical information and messages. It is argued that statistically literate behavior is predicated on the joint activation of five interrelated knowledge bases (literacy, statistical, mathematical, context, and critical), together with a cluster of supporting dispositions and enabling beliefs. Educational and research implications are discussed, and responsibilities facing educators, statisticians, and other stakeholders are outlined.
How Likelihood and Identification went Bayesian
Authors: Aldrich John
Published: May 2007

This paper considers how the concepts of likelihood and identification became part of Bayesian theory. This makes a nice study in the development of concepts in statistical theory. Likelihood slipped in easily but there was a protracted debate about how identification should be treated. Initially there was no agreement on whether identification involved the prior, the likelihood or the posterior.
What Makes Business Statistics Special?
Authors: Riviére Pascal
Published: May 2007

Non‐specialists might have the feeling that building statistics on businesses is a very simple task: it seems one just has to “add facts”. But for survey statisticians, business statistics are extremely complex: great heterogeneity of the universe, definition of the statistical units, difficulty of classifying businesses, quality of the register, variety of accounting standards, sample co‐ordination, or reduction of survey burden. This paper argues that the issues raised by business survey methodology are conceptual and not only practical. It describes different aspects of statistical processing and tries to analyse the special features of business statistics.
Seeing and Doing: the Concept of Causation
Authors: Lindley Dennis V.
Published: May 2007

This note is an extended review of the book by Judea Pearl (2000) on causality, in which the basic concepts therein are explained in a form that statisticians will hopefully appreciate, including some comments on their relevance to inference and decision‐making.
MC's for MCMC'ists
Authors: Nummelin Esa
Published: May 2007

We develop a minimum amount of theory of Markov chains at as low a level of abstraction as possible in order to prove two fundamental probability laws for standard Markov chain Monte Carlo algorithms:

1. The law of large numbers explains why the algorithm works: it states that the empirical means calculated from the samples converge towards their “true” expected values, viz. expectations with respect to the invariant distribution of the associated Markov chain (=the target distribution of the simulation).

2. The central limit theorem expresses the deviations of the empirical means from their expected values in terms of asymptotically normally distributed random variables. We also present a formula and an estimator for the associated variance.
TRANSFORMATIONS BETWEEN STURM–LIOUVILLE PROBLEMS WITH EIGENVALUE DEPENDENT AND INDEPENDENT BOUNDARY CONDITIONS
Authors: BINDING PAUL A. , BROWNE PATRICK J. , WATSON BRUCE A.
Published: May 2007

Explicit relationships are given connecting ‘almost’ isospectral Sturm–Liouville problems with
eigen-value dependent, and independent, boundary conditions, respectively. Application is made to various
direct and inverse spectral questions.
A STRATIFICATION FOR VARIETIES OF MODULES
Authors: RICHMOND NICOLA J.
Published: May 2007

This paper introduces a stratification of the variety of modules of a fixed dimension over a finite-dimensional
algebra. For a large and interesting class of algebras, called subfinite, this stratification
is used to compute the dimension of this variety and give bounds on the number of its irreducible
components.
FIBRÉS STABLES DE PENTE 2
Authors: MERCAT VINCENT
Published: May 2007

We give here a detailed description of the Brill–Noether loci of stable vector bundles of slope 2 on a
smooth projective curve, which is assumed to be nonhyperelliptic.
ON AN EXTENSION PROBLEM FOR POLYNOMIALS
Authors: BAKONYI MIHÁLY , TIMOTIN DAN
Published: May 2007

Consider the following problem: given complex numbers
a1, …, an,
find an L∞ function f of minimum norm whose Fourier coefficients
ck(f) are equal to ak for k between 0 and
n. We show the uniqueness of this function, and we estimate its norm.
The operator-valued case is also discussed.
OBITUARY NATHAN JACOBSON (1910–1999)
Authors: COHN P. M.
Published: May 2007

Nathan Jacobson, who died on 5 December 1999, was an outstanding algebraist,
whose work on almost all aspects of algebra was of fundamental importance, and
whose writings will exercise a lasting influence. He had been an honorary member
of the Society since 1972.

Nathan Jacobson (later known as ‘Jake’ to his friends) was born in Warsaw (in
what he describes as the ‘Jewish ghetto’) on 5 October 1910 (through an error some
documents have the date 8 September); he was the second son of Charles Jacobson
(as he would be known later) and his wife Pauline, née Rosenberg. His family
emigrated to the USA during the First World War, first to Nashville, Tennessee,
where his father owned a small grocery store, but they then settled in Birmingham,
Alabama, where Nathan received most of his schooling. Later the family moved to
Columbus, Mississippi, but the young Nathan entered the University of Alabama
in 1926 and graduated in 1930. His initial aim was to follow an uncle and obtain a
degree in law, but at the same time he took all the (not very numerous) mathematics
courses, in which he did so well that he was offered a teaching assistantship in
mathematics in his junior (3rd) year. This marked a turning point; he now decided
to major in mathematics and pursue this study beyond College. During his final
year at Alabama he applied for admission and financial aid to three top graduate
schools in the country: Princeton, Harvard and Chicago. He was awarded a research
assistantship at Princeton; after the first year he was appointed a part-time instructor
for two years, and during his fourth year he was appointed a Procter Fellow. The
stipend was enough to enable him to make a grand tour of Europe by car in 1935,
in the company of two Princeton fellow-students at the time: H. F. Bohnenblust and
Robert J. Walker.
UNICELLULAR DESSINS AND A UNIQUENESS THEOREM FOR KLEIN'S RIEMANN SURFACE OF GENUS 3
Authors: SINGERMAN DAVID
Published: May 2007

If we consider the 14-sided hyperbolic polygon of Felix Klein that defines his famous surface of genus
3, then we observe that we have a uniform, unifacial dessin whose automorphism group is transitive on
the edges, but not on the directed edges of the dessin. We show that Klein's surface is the unique platonic
surface with this property.
CROSSED PRODUCT ORDERS OVER VALUATION RINGS
Authors: KAUTA JOHN S.
Published: May 2007

Let V be a commutative valuation domain of arbitrary Krull-dimension (rank), with quotient field F,
and let K be a finite Galois extension of F with group G,
and S the integral closure of V in K. If,
in the crossed product algebra K [midast ] G, the 2-cocycle
takes values in the group of units of S, then one can form, in a natural way, a ‘crossed product
order’ S [midast ] G ⊆ K [midast ] G. In the light of recent results
by H. Marubayashi and Z. Yi on the homological dimension of crossed products, this paper discusses
necessary and/or sufficient valuation-theoretic conditions, on the extension
K/F, for the V-order S [midast ] G
to be semihereditary, maximal or Azumaya over V.
THE HEAT FLOW OF THE CCR ALGEBRA
Authors: ARVESON WILLIAM
Published: May 2007

Let Pf(x) =−if′(x) and Qf(x) = xf(x) be the canonical operators acting on an appropriate common
dense domain in L2(ℝ). The derivations DP(A) = i(PA−AP) and DQ(A) = i(QA−AQ) act on the
*-algebra [Ascr ] of all integral operators having smooth kernels of compact support, for example, and one
may consider the noncommutative ‘Laplacian’, L = D2P+D2Q, as a linear mapping of [Ascr ] into itself.

L generates a semigroup of normal completely positive linear maps on [Bscr ](L2(ℝ)), and this paper
establishes some basic properties of this semigroup and its minimal dilation to an E0-semigroup. In
particular, the author shows that its minimal dilation is pure and has no normal invariant states, and he
discusses the significance of those facts for the interaction theory introduced in a previous paper.

There are similar results for the canonical commutation relations with n degrees of freedom, where
1 [les ] n < 1.
ON NON-EQUIVALENCE OF QUADRATIC FORMS ON A RIEMANNIAN MANIFOLD
Authors: LEVIN DANIEL
Published: May 2007

An example is constructed of a manifold for which two quadratic forms corresponding to the fourth-order
invariant operators are not equivalent.
PARITY OF THE PARTITION FUNCTION IN ARITHMETIC PROGRESSIONS, II
Authors: BOYLAN MATTHEW , ONO KEN
Published: May 2007

Let p(n) denote the ordinary partition function. Subbarao conjectured that in every arithmetic
progression r (mod t) there are infinitely many integers
N ≡ r (mod t) for which p(N) is even, and infinitely many
integers M ≡ r (mod t) for which p(M) is odd.
We prove the conjecture for every arithmetic progression whose modulus is a power of 2.
A VANISHING THEOREM FOR THE HEAT CONTENT OF A RIEMANNIAN MANIFOLD
Authors: VAN DEN BERG M.
Published: May 2007

The paper considers the asymptotic behaviour of the heat content of a riemannian manifold M, when
Dirichlet conditions are imposed on a small compact subset of M.
ON DIFFERENCE FIELDS WITH QUANTIFIER ELIMINATION
Authors: MOOSA RAHIM
Published: May 2007

This paper proves that a difference field (E, σ) admits quantifier elimination if and only if E is an
algebraically closed field, and σ is an integer power of the Frobenius automorphism.
BOUNDED GENERATION AND SUBGROUP GROWTH
Authors: PYBER L.
Published: May 2007

The author proves in this paper that every profinite group G with polynomial subgroup growth is
boundedly generated; that is, it is a product of finitely many procyclic subgroups. This answers a
question of P. Zalesskii. By contrast, if G is a boundedly generated group, then the subgroup growth of
G is at most nclogn . As a byproduct, a short, elementary proof demonstrates that Aut(Fr) (for r [ges ] 2) and
many other related groups are not boundedly generated.
Volumes of Hyperbolic 3‐Manifolds of Betti Number at Least 3
Authors: Przeworski Andrew
Published: May 2007

This paper provides a new, simpler proof of the fact that the smallest volume hyperbolic 3‐manifold has betti number at least 3. In the process, the best known lower bound on the volume of such a manifold is improved.
INVOLUTORY HOPF ALGEBRAS WITH NON-ZERO INTEGRALS
Authors: DĂSCĂLESCU S. , NĂSTĂSESCU C. , TORRECILLAS B.
Published: May 2007

The authors prove in this paper that an involutory Hopf algebra with non-zero integral over a field of
characteristic zero is cosemisimple.
MULTIQUADRATIC EXTENSIONS, RIGID FIELDS AND
PYTHAGOREAN FIELDS
Authors: LEEP DAVID B. , SMITH TARA L.
Published: May 2007

Let F be a field of characteristic other than 2. Let F(2) denote the compositum over F of all quadratic
extensions of F, let F(3) denote the compositum over F(2) of all quadratic extensions of F(2) that are
Galois over F, and let F{3} denote the compositum over F(2) of all quadratic extensions of F(2). This
paper shows that F(3) = F{3} if and only if F is a rigid field, and that F(3) = K(3) for some extension K
of F if and only if F is Pythagorean and K = F(√−1). The proofs depend mainly on the behavior of
quadratic forms over quadratic extensions, and the corresponding norm maps.
SET IDEALS WITH ISOMORPHIC SYMMETRY GROUPS
Authors: BIRYUKOV PETER , MISHKIN VALERY
Published: May 2007

A criterion of isomorphism for symmetry groups of set ideals is provided in terms of ideal quotients and
cardinal invariants. Furthermore, set ideals with complete symmetry group are characterized. They form
a wide class, comprising, for example, all uniform dense ideals and the ideals of ‘thin’ sets in separable
metric spaces. If the symmetry group of a set ideal is not complete, then its outer automorphism group
is shown to be cyclic of order 2.
Periodic Solutions of Forced Oscillators with Several Degrees of Freedom
Authors: Ortega Rafael , Sánchez Luis A.
Published: May 2007

Results of the Landesman–Lazer type provide necessary and sufficient conditions for the existence of periodic solutions of certain nonlinear differential equations with forcing. Typically, they deal with scalar problems. This paper presents a discussion of possible extensions to systems. The emphasis is placed on the new phenomena produced by the increase of the dimension.
NEW SUFFICIENT CONDITIONS FOR THE DENSENESS OF
NORM ATTAINING MULTILINEAR FORMS
Authors: PAYÁ RAFAEL , SALEH YOUSEF
Published: May 2007

This paper gives new sufficient conditions for the density of the set of norm attaining multilinear forms
in the space of all continuous multilinear forms on a Banach space. The symmetric case is also discussed.
ON POLYNOMIAL SEQUENCES WITH RESTRICTED
GROWTH NEAR INFINITY
Authors: MÜLLER J. , YAVRIAN A.
Published: May 2007

Let (Pn) be a sequence of polynomials which converges with a geometric rate on some arc in the complex
plane to an analytic function. It is shown that if the sequence has restricted growth on a closed plane
set E which is non-thin at ∞, then the limit function has a maximal domain of existence, and (Pn)
converges with a locally geometric rate on this domain. If (snk) is a sequence of partial sums of a power
series, a similar growth restriction on E forces the power series to have Ostrowski gaps. Moreover, the
requirement of non-thinness of E at ∞ is necessary for these conclusions.
An Asymptotically Good Tower of Curves Over the Field With Eight Elements
Authors: Van Der Geer Gerard , Van Der Vlugt Marcel
Published: May 2007

An explicit, asymptotically good, tower of curves over the field with eight elements is constructed. The genus and the number of rational points are calculated explicitly.
GALOIS THEORIES (Cambridge Studies in Advanced Mathematics 72)
Authors: Byott Nigel
Published: May 2007

By Francis Borceux and George Janelidze: 341 pp., £50.00, isbn 0‐521‐80309‐8(Cambridge University Press, 2001).
GEOMETRY AND TOPOLOGY OF CONFIGURATION SPACES (Springer Monographs in Mathematics)
Authors: Tillmann Ulrike
Published: May 2007

By Edward R. Fadell and Sufian Y. Husseini: 313 pp., £58.50, isbn 3‐540‐66669‐9 (Springer, Berlin, 2001).
CLASSICAL AND MODERN METHODS IN SUMMABILITY (Oxford Mathematical Monographs)
Authors: Thorpe B.
Published: May 2007

By Johann Boos, assisted by Peter Cass: 586 pp., £75.00, isbn 0‐19‐850165‐X(Oxford University Press, 2000).
CONES OF CURVES AND OF LINE BUNDLES ON SURFACES ASSOCIATED WITH CURVES HAVING ONE PLACE AT INFINITY
Authors: CAMPILLO ANTONIO , PILTANT OLIVIER , REGUERA-LÓPEZ ANA J.
Published: May 2007

Let V be a pencil of curves in ${\bf P}^2$ with one place at infinity, and $X \longrightarrow {\bf P}^2$ the minimal composition of point blow-ups eliminating its base locus. We study the cone of curves and the cones of numerically effective and globally generated line bundles on X. It is proved that all of these cones are regular. In particular, this result provides a new class of rational projective surfaces with a rational polyhedral cone of curves. The surfaces in this class have non-numerically effective anticanonical sheaf if the pencil is neither rational nor elliptic.
An application is a global version on X of Zariski's unique factorization theorem for complete ideals. We also define invariants of the semigroup of globally generated line bundles on X depending only on the topology of V at infinity.

2000 Mathematical Subject Classification: primary 14C20; secondary 14E05.
FANS AND LADDERS IN SMALL CANCELLATION THEORY
Authors: McCAMMOND JONATHAN P. , WISE DANIEL T.
Published: May 2007

This paper provides a strengthening of the theorems of small cancellation theory. It is proven that disc diagrams contain 'fans' of consecutive 2-cells along their boundaries. The size of these fans is linked to the strength of the small cancellation conditions satisfied by the diagram. A classification result is proven for disc diagrams satisfying small cancellation conditions. Any disc diagram either contains three fans along its boundary, or it is a ladder, or it is a wheel. Similar statements are proven for annular diagrams.

2000 Mathematical Subject Classification: 20F06.
A BANACH SPACE WHOSE OPERATOR ALGEBRA HAS K0-GROUP ℚ
Authors: ZSÁK ANDRÁS
Published: May 2007

We construct a Banach space X whose algebra of bounded linear operators has K0-group the additive group of rational numbers. We achieve this using a Gowers-Maurey space.

2000 Mathematical Subject Classification: 20F36, 55P35, 55Q05, 55Q40, 55U10
REGULARIZABLE CYCLES ASSOCIATED WITH A SELBERG TYPE INTEGRAL UNDER SOME RESONANCE CONDITION
Authors: MIMACHI KATSUHISA , YOSHIDA MASAAKI
Published: May 2007

Twisted homology groups attached to a Selberg type integral are studied under some resonance condition. We study the kernel of the map from the homology of compact cycles to the homology of locally finite cycles. As a result, the dimension of the image, the space of the regularizable cycles, is expressed as a special value of the generalized hypergeometric series 3F2.
MISSION LEVEL MODELING AND SIMULATION LANGUAGE FOR MIXED-SIGNAL SYSTEM-ON-CHIP DESIGN
Authors: ANDJELKOVIĆ BOJAN , LITOVSKI VANCO , ZERBE VOLKER
Published: May 2007

Modern complex system design demands modeling on a high level of abstraction together with the system environment components. Such model enables mission level system simulation in the context of its operational conditions. Mission level design using hardware description language AleC++ is presented in this paper. It provides mission and system level verification of a mixed-signal system-on-chip. After validation at mission and system level, this language enables designers to replace some of the components with implementation level models to test and validate the system implementation at mission level. Also, the language provides modeling capabilities that give the designer an opportunity to analyze the influence of low-level technological and environmental parameters to the complete system behavior. In this way a uniform design framework is achieved from mission/system down to implementation level. The application of the language both for mission/system and implementation level modeling is illustrated by an example of the electronic compass.
VOLTAGE-MODE DDCC-BASED MULTIFUNCTION FILTERS
Authors: CHEN HUA-PIN , WU KUO-HSIUNG
Published: May 2007

Two new voltage-mode multifunction biquadratic filter configurations were proposed. The first proposed high-input impedance multifunction filter with single input and four outputs, which can simultaneously realize voltage-mode low-pass, band-pass, and high-pass filter responses employing all grounded passive components. The second proposed configuration is a slight modification of the first proposed circuit. It leads two more notch and all-pass transfer functions than the first proposed circuit. Moreover, both the proposed circuits still offer the following advantages: (i) orthogonal control of ωo and Q, (ii) low active and passive sensitivity performances, (iii) simpler configuration due to the use of noninverting type differential difference current conveyors (DDCCs) only.
A CRITERION OF A MULTI-LOOP OSCILLATOR CIRCUIT
Authors: HOU CHUN-LI , HUANG CHEN-CHUAN , HORNG JIUN-WEI
Published: May 2007

Multi-loop feedback control has attracted considerable attention due to its simplicity and ease of implementation.1 In order to simplify the cumbersome analysis of a multi-loop circuit, the signal flow graph representation should be used rather than our familiar nodal analysis methods. This paper presents a criterion from the well-established Mason's formula for multi-loop oscillator in terms of signal flow graphs. The multi-loop oscillator circuit based on two operational transresistance amplifiers (OTRAs) is used as an example.
NETWORK PROCESSOR FOR HIGH-SPEED NETWORK AND QUICK PROGRAMMING
Authors: MUROOKA TAKAHIRO , NAGOYA AKIRA , MIYAZAKI TOSHIAKI , OCHI HIROYUKI , NAKAMURA YUKIHIRO
Published: May 2007

The paper describes the concept, architecture, and prototype test results of a packet processor that enables us to implement an application-specific high-speed packet processing system without expert-level programming skills. This processor has a pipelined processing architecture and features coarse-grained instructions that are based on the data formats of the telecommunication packet. Using this processor, target applications can be implemented within a short working period without degrading the processing performance. We implemented a prototype system to evaluate its packet propagation delay and packet forwarding performance. The measured results suggest that the architecture is useful for packet processing on high-speed telecommunication networks.
LOW REFLECTION HIGH-SPEED SIMULTANEOUS BI-DIRECTIONAL DATA BUS
Authors: XIA TIAN , FENG KAIDI , YUNG WAI
Published: May 2007

In this paper, a new Simultaneous Bi -directional Data Bus architecture has been presented. The new architecture provides stable and consistent impedance matching to the transmission channel, which can significantly reduce reflections and ensure the signal integrity and transmission reliability. To validate the design, an in-depth comparative study has been performed.
KNOTS OF CONSTANT CURVATURE
Authors: GANATRA JENELLE MARIE McATEE
Published: May 2007

In this paper, we show how to realize all knot (and link) types as [Formula: see text] smooth curves of constant curvature. Our proof is constructive: we build the knots with copies of a fixed finite number of "building blocks" that are particular segments of helices and circles. We use these building blocks to construct all closed braids.
LINKING NUMBER IN A PROJECTIVE SPACE AS THE DEGREE OF A MAP
Authors: VIRO DROBOTUKHINA JULIA
Published: May 2007

For any two disjoint oriented circles embedded into the 3-dimensional real projective space, we construct a 3-dimensional configuration space and its map to the projective space such that the linking number of the circles is the half of the degree of the map. Similar interpretations are given for the linking number of cycles in a projective space of arbitrary odd dimension and the self-linking number of a zero homologous knot in the 3-dimensional projective space.
UNIVERSAL TRELLISES
Authors: COLLINS PIETER
Published: May 2007

A flow in three-dimensions is universal if the periodic orbits contains all knots and links. Universal flows were shown to exist by Ghrist, and can be constructed by means of templates. Likewise, a planar diffeomorphism is universal if it has a suspension flow which is a universal flow. In this paper we prove the existence of a homoclinic trellis type for which any representative diffeomorphism is universal. This trellis type is remarkable in that it has zero entropy, and only two homoclinic intersection points.
CREDIBILITY MEASURE-BASED FUZZY MEMBERSHIP GRADE KRIGING
Authors: GUO DANNI , GUO RENKUAN , THIART CHRISTIEN
Published: May 2007

A fundamental problem in fuzzy analysis is that the membership function is specified subjectively. In other words, the modelers specify the membership function form and assign the values of the parameters in membership function via their working experiences. Different from its probabilistic counterpart, fuzzy mathematical theory does not provide convenient parameter estimation approach. In this paper, we first review Liu's non-classical credibility measure theory (i.e., (∨,·)-credibility measure theory) in Liu7, because the fuzzy theory initiated by Zadeh10 contains a critical weakness: non self-duality property for possibility measure. We establish a parameter estimation of the membership function in terms of maximum entropy principle on the ground of self-dual credibility measure theory. Furthermore, based on the data assimilated membership function, we can calculate membership grades on the fuzzy environmental index, using PM10 air pollution as an illustration. We treat the calculated membership grades as spatially distributed random quantity, and therefore perform the standard ordinary kriging approach for generating the predicted environmental index map, for PM10 prediction map.
ON SENSITIVITY RANKING USING ANALYTIC HIERARCHY PROCESS
Authors: DANG HUNG
Published: May 2007

We present an application of the Analytic Hierarchy Process (AHP) in the sensitivity analysis of a multi-parameter decision support problem. In this problem, the Multi-Parametric Sensitivity Analysis (MPSA) appears appropriate and is employed. A drawback of MPSA is that it only produces a sensitivity comparison between every two parameters, and does not offer a systematic method for ranking all parameters at once. Without the overall sensitivity ranking, it is difficult to interpret the analysis result from MPSA, especially when the number of parameters is large. Our paper shows that AHP can be used to perform such ranking based on MPSA's pair-wise comparisons.
A FUZZY PROGRAMMING APPROACH FOR SUPPLY CHAIN NETWORK DESIGN
Authors: JI XIAOYU , ZHAO XIANDE , ZHOU DEMING
Published: May 2007

This paper presents a fuzzy programming method to design supply chain network, in which the customer demands and transportation costs are assumed to be fuzzy parameters. Existing researches on supply chain network design problem are either restricted on deterministic environment or only address stochastic parameters. In this paper, we consider this problem in fuzzy environment. Under different criteria, we format three types of models for the decision makers: expected cost optimization model, chance-constrained model and chance maximization model. A genetic algorithm based on fuzzy simulation is developed to solve the proposed fuzzy models. Moreover, some numerical examples are presented to illustrate the effectiveness of models and solution algorithm.
FUZZY RANDOM DEGREE-CONSTRAINED MINIMUM SPANNING TREE PROBLEM
Authors: LIU WEI , YANG CHENGJING
Published: May 2007

The degree-constrained minimum spanning tree problem (dc-MST) is to find a minimum spanning tree of the given graph, subject to constraints on node degrees. This paper investigates the dc-MST problem with fuzzy random weights. Three concepts are presented: expected fuzzy random dc-MST, (α,β)-dc-MST and the most chance dc-MST according to different optimization requirement. Correspondingly, by using the concepts as decision criteria, three fuzzy random programming models for dc-MST are given. Finally, a hybrid intelligent algorithm is designed to solve these models, and some numerical examples are provided to illustrate its effectiveness.
A GENERALIZED APPROACH TO POSSIBILISTIC CLUSTERING ALGORITHMS
Authors: ZHOU JIAN , HUNG CHIH-CHENG
Published: May 2007

Fuzzy clustering is an approach using the fuzzy set theory as a tool for data grouping, which has advantages over traditional clustering in many applications. Many fuzzy clustering algorithms have been developed in the literature including fuzzy c-means and possibilistic clustering algorithms, which are all objective-function based methods. Different from the existing fuzzy clustering approaches, in this paper, a general approach of fuzzy clustering is initiated from a new point of view, in which the memberships are estimated directly according to the data information using the fuzzy set theory, and the cluster centers are updated via a performance index. This new method is then used to develop a generalized approach of possibilistic clustering to obtain an infinite family of generalized possibilistic clustering algorithms. We also point out that the existing possibilistic clustering algorithms are members of this family. Following that, some specific possibilistic clustering algorithms in the new family are demonstrated by real data experiments, and the results show that these new proposed algorithms are efficient for clustering and easy for computer implementation.
A MONTE CARLO SIMULATION BASED APPROACH FOR STOCHASTIC SEMI-INFINITE MATHEMATICAL PROGRAMMING PROBLEMS
Authors: LUHANDJULA M. K.
Published: May 2007

The paper deals with stochastic mathematical programming problems with additional difficulty brought up by the presence of infinitely many constraints. A sample average approximation (SAA) approach is proposed and properties of SAA estimators, analyzed. It is shown that for the case of deterministic constraints, SAA estimators are consistent and meet requirements to qualify the estimates as acceptable approximations of unknown values. Moreover, good error bounds of the estimate of the objective function are provided. We also discuss a Galerkin-like scheme and a tailored cutting-plane method for solving resulting semi-infinite SAA problems. The framework is then extended to the case of random constraints through Karhunen–Loève expansion or constraints approximation via sampling. A general procedure for solving stochastic semi-infinite programming problems, that lends itself better for parallel computation, is then described. Numerical examples are also included for the sake of illustration.
Melatonin Levels during the First Week of Life and Their Relation with the Antioxidant Response in the Perinatal Period
Authors: Muñoz-Hoyos A. , Bonillo-Perales A. , Ávila-Villegas R. , González-Ripoll M. , Uberos J. , Florido-Navío J. , Molina-Carballo A.
Published: May 2007

Aim: Melatonin is a potent free radical scavenger and an indirect antioxidant. Knowledge about the behavior of melatonin secretion in the early neonatal period, which may relate to its properties at a vital stage during very high antioxidant demands, is limited. Patients and Methods: We studied 35 newborns admitted to the Neonatal Unit with respiratory distress syndrome (RDS) and with no signs of sepsis, severe anemia, hemodynamic compromise or malformation. The gestational age of the newborns was 26–40 weeks (mean value 32.5 weeks) and the weight at birth was 870–4,400 g (mean value 1,800 g). They were classified into two groups: ≤1,500 g or >1,500 g birthweight. In all cases, at 09:00 h on their 1st, 3rd and 7th days of life, serum melatonin was measured by RIA. The clinical history was recorded and treatment and follow-up were performed according to established neonatology practice, and the resultant data recorded. Informed consent from the parents or guardians was obtained in accordance with the Declaration of Helsinki. Statistical analysis was carried out using ANOVA-II (factor I: day of sample; factor II: birthweight). Results: There were significant increases in melatonin levels with increasing birthweight (p = 0.017), but no changes by day of sample. Although in both study groups melatonin levels increased during the first few days this was not statistically significant. Conclusions: In newborns of low birthweight, we report high melatonin concentrations in the morning and during the first week of life. These increase with maturation, and at full-term were similar to nocturnal levels during the acrophase of pineal gland secretion in toddlers and schoolage children, when pineal gland secretion is maximal and takes place reflecting environmental variations. In the early neonatal period these high levels of melatonin seem to derive from extrapineal sources, which mature to provide antioxidant protection in accordance with other elements of the antioxidant network to compensate for the high levels of oxidative stress that are present in the perinatal period.
Cone Photoreceptor Diversity in the Retinas of Fruit Bats (Megachiroptera)
Authors: Müller Brigitte , Goodman Steven M. , Peichl Leo
Published: May 2007

Older studies have claimed that bats including the Megachiroptera (fruit bats or flying foxes) have pure-rod retinas and possess no cone photoreceptors. We have determined the presence and the population densities of spectral cone types in six megachiropteran species belonging to four genera: Pteropus rufus, P. niger, P. rodricensis, Rousettus madagascariensis, Eidolon dupreanum, and Epomophorus gambianus. Spectral cone types and rods were assessed immunocytochemically with opsin-specific antibodies. All six species have rod-dominated retinas but possess significant cone populations. The high rod densities (range 350,000–800,000/mm2, depending on species and retinal location) provide good scotopic sensitivity in these predominantly nocturnal animals. With the cones (density range 1,300–11,000/mm2, corresponding to 0.25–0.6% of the photoreceptors, depending on species and retinal location) the retinas also possess the prerequisite for vision at photopic light levels. The three Pteropus species have two spectral cone types, a majority of middle-to-long-wave sensitive (L-) cones, and a minority of short-wave sensitive (S-) cones, indicating the potential for dichromatic color vision. This conforms to the pattern found in most mammals. In contrast, Rousettus, Eidolon and Epomophorus have L-cones but completely lack S-cones, indicating cone monochromacy and color blindness. The discussion relates these findings to the visual behavior of fruit bats.