bluuebunny/crossref_metadata_2025_split huggingface dataset:
Moderate-aspect-ratio elliptical cylinders in simple shear with inertia
Authors: ZETTNER C. M. , YODA M. 
Published: July 2002

The effects of fluid inertia, geometry and flow confinement upon the dynamics of
neutrally buoyant elliptical and non-elliptical cylinders over a wide range of aspect
ratios in simple shear are studied experimentally for moderate shear-based Reynolds
numbers Re. Unlike circular cylinders, elliptical cylinders of moderate aspect ratio
cease to rotate, coming to rest at a nearly horizontal equilibrium orientation above a
critical Reynolds number Recr (‘stationary behaviour’). Simple dynamics arguments
are proposed to explain the effects of aspect ratio and flow confinement upon
critical Reynolds number and particle dynamics. Experiments confirm results from
previous numerical simulations that the normalized rotation period for Re < Recr
(‘periodic behaviour’) is proportional to
(Recr − Re)−0.5
for small Recr − Re. For
periodic behaviour, maximum and minimum angular cylinder speeds both decrease,
and period increases, as Recr − Re decreases.
For stationary behaviour, the cylinder
rotates until it achieves a nearly horizontal equilibrium orientation, which increases
as the Reynolds number approaches the critical value. The experimental results are
in good agreement with previous lattice-Boltzmann simulations for a 0.5 aspect ratio
cylinder.Variation in angular speed over a rotation period decreases as aspect ratio increases,
while Recr increases as flow confinement and aspect ratio increase. A non-elliptical
cylinder of 0.33 aspect ratio also ceases to rotate above a certain Reynolds number.
Although Recr is different from the corresponding elliptical case, the scaling of the
normalized rotation period for this body as Recr → Re
is identical to that for the elliptical cylinder, suggesting that this scaling is independent of particle shape (i.e.
‘universal’, as conjectured in previous numerical studies). The results also demonstrate
that a variety of centrosymmetric bodies with aspect ratios below unity transition
from periodic to stationary behaviour.
The generation of internal waves by vibrating

elliptic cylinders. Part 2. Approximate viscous solution
Authors: HURLEY D. G. , KEADY G. 
Published: July 2002

An approximate theory is given for the generation of internal

gravity waves in a viscous

Boussinesq fluid by the rectilinear vibrations of an elliptic cylinder.
A

parameter λ

which is proportional to the square of the ratio of the thickness of the
oscillatory

boundary layer that surrounds the cylinder to a typical dimension

of its cross-section

is introduced. When λ[Lt ]1 (or equivalently when the Reynolds number

R[Gt ]1), the

viscous boundary condition at the surface of the cylinder may to first

order in λ be

replaced by the inviscid one. A viscous solution is proposed for the case

λ[Lt ]1 in which

the Fourier representation of the stream function found in Part 1 (Hurley
1997) is

modified by including in the integrands a factor to account for viscous

dissipation. In

the limit λ→0 the proposed solution becomes the inviscid one

at each point in the flow field.For ease of presentation the case of a circular cylinder of radius

a is considered first

and we take a to be the typical dimension of its cross-section
in

the definition of λ

above. The accuracy of the proposed approximate solution is investigated
both

analytically and numerically and it is concluded that it is accurate

throughout the flow

field if λ is sufficiently small, except in a small region near

where the characteristics touch the cylinder where viscous effects dominate.Computations indicate that the velocity on the centreline on a typical

beam of waves, at a distance s along the beam from the centre of the cylinder,

agrees, within about 1%,

with the (constant) inviscid values provided λs/a

is less than about 10−3. This result is

interpreted as indicating that those viscous effects which originate from
the

characteristics that touch the cylinder (places where the inviscid velocity

is singular)

reach the centreline of the beam when λs/a

is about 10−3. For larger values of s, viscous

effects are significant throughout the beam and the velocity profile of
the

beam changes

until it attains, within about 1% when λs/a

is about 2, the value given by the similarity

solution obtained by Thomas & Stevenson (1972). For larger values of

λs/a, their similarity solution applies.In an important paper Makarov et al. (1990) give an approximate

solution for the

circular cylinder that is very similar to ours. However, it does not reduce

to the inviscid one when the viscosity is taken to be zero.Finally it is shown that our results for a circular cylinder apply,
after small

modifications, to all elliptical cylinders.
Secondary flows and developing, turbulent boundary layers in a rotating
duct
Authors: MACFARLANE I. , JOUBERT P. N. , NICKELS T. B. 
Published: July 2002

The work presented in this paper represents an experimental investigation
into
secondary flows, turbulent boundary layers and the interaction of the two
as they
develop in a zero-pressure-gradient rotating flow field. A duct of intermediate
aspect
ratio was used to examine secondary flows and determine when they begin
to govern
the boundary layer development. The aspect ratio (A)
was defined as duct height/width
at the upstream end of the working section. Measurements were taken at
three aspect
ratios: A=1, 2 and 4.A qualitative indication of secondary flow strength was established
with
mean-cross-stream-plane velocity measurements. A first-order analysis of
the secondary flow is
presented which provides a reasonable estimation of their strength. Mid-span
mean-flow,
turbulence and spectra profiles were measured on the duct walls parallel
to the
axis of rotation. Results are generally presented for A=2 and
1.
For A=4 and 2 there
were minor effects of secondary flows observed on the mid-span mean flow
parameters.
The turbulent shear measurements showed some secondary flow effect for
A=2. All
turbulence and mean-flow quantities were strongly affected by secondary
flows for
A=1. Spectra results presented for A=2 showed most variation
at the low-to-mid
wavenumber end. Spectra results for A=1 showed a bodily shift of
the whole
spectrum towards low wavenumber on the pressure side and high wavenumber
on the
suction side.
The spiral wind-up and dissipation of vorticity and a passive scalar in a strained planar vortex
Authors: BASSOM ANDREW P. , GILBERT ANDREW D. 
Published: July 2002

The response of a Gaussian vortex to a weak time-dependent external strain field is
studied numerically. The cases of an impulsive strain, an on–off step function, and a
continuous random strain are considered. Transfers of enstrophy between mean and
azimuthal components are observed, and the results are compared with an analogous
passive scalar model and with Kida's elliptical vortex model.A ‘rebound’ phenomenon is seen: after enstrophy is transferred from mean to
azimuthal component by the external straining field, there is a subsequent transfer
of enstrophy back from the azimuthal component to the mean. Analytical support
is given for this phenomenon using Lundgren's asymptotic formulation of the spiral
wind-up of vorticity. Finally the decay of the vortex under a continuous random
external strain is studied numerically and compared with the passive scalar model.
The vorticity distribution decays more slowly than the scalar because of the rebound
phenomenon.
Ethnic minority suicide: a small area geographical
study in south London
Authors: NEELEMAN JAN , WESSELY SIMON 
Published: July 2002

Background. The relationship between ethnicity and suicide
risk is ill-understood. It is unclear
whether, and if so, how, the ethnic mix of local areas affects risk in
local individuals.Methods. Coroners' records of 329 suicides were used to
obtain ethnic (White, Afro-Caribbean,
Asian) suicide rates in South London (population 902008) for 1991–3.
Geographical variation and
associations of ethnic suicide rates with small area (mean population 8274)
ethnic densities
(proportion of residents of given ethnic groups) and deprivation, were
examined with random
effects Poisson regression.Results. Adjusted for deprivation, age and gender, suicide
rates in wards with larger minority
groups were higher among Whites (relative rate (RR) per standard deviation
(S.D.)
increase in minority density 1·18; 95% CI 1·02–1·37)

but lower among minority groups (RR 0·75 (0·59–0·96))

(LR-test for interaction χ2=9·2 (df=1); P=0·003).

Similar patterns were also apparent for Afro-Caribbeans and Asians
separately. With White suicide rates as baseline, ethnic minority status
is a
risk factor for suicide in wards with small, but a protective factor in
neighbourhoods with large
minority populations. The RR of minority versus White suicide
declines with a factor (relative RR)
0·67 (0·51–0·87) per S.D. increase
in local minority density.Conclusions. Minority suicide rates are higher in areas where minority
groups are smaller. This effect
is ethnic-specific and not due to confounding by gender, age, deprivation
or unbalanced migration.
Dependent on address, a suicide risk factor for a White individual may
protect an ethnic minority
individual and vice versa. This has implications for research and prevention.
REM and NREM mentation: Nielsen's model once again supports the supremacy of REM
Authors: Bosinelli M. , Cicogna P.C. 
Published: July 2002

Nielsen's model presents a new isomorphic brain-mind viewpoint, according to which the sole dream generator is found in a REM-on (explicit or covert REM) mechanism. Such a model cannot explain the dreamlike activity during SWS (slow wave sleep), SO (sleep onset) and in the last period of sleep. Moreover the hypothesis contrasts with Solms's data, which show that dreaming is present also in case of destruction of the REM generator.[Nielsen; Solms]
The mechanism of the REM state is more than a sum of its parts
Authors: Solms Mark 
Published: July 2002

Nielsen has not demonstrated that NREM dreams are regularly accompanied by fragments of the REM state. However, even if this hypothetical correlation could be demonstrated, its physiological basis would be indeterminate. The REM state is a configuration of physiological variables, the basis of which is a control mechanism that recruits and coordinates multiple sub-mechanisms into a stereotyped pattern. The diverse sub-mechanisms underlying each individual component of the REM state do not have an intrinsic relationship with the REM state itself.[Nielsen]
European Policy Issues
Authors: Maltby Tony 
Published: July 2002

Shaver, S. (1988) ‘Universality or selectivity in income
support to
older people? A comparative assessment of the issues’, Journal
of
Social Policy, 27 (2), 231–254.Reynaud, E. (1998) ‘Pensions in the European Union: adapting to

economic and social changes’. International Social Security Review,
51
(1), 31–47.These two articles are highlighted as both offer the reader some insights
into
the ongoing debate on the level of income in later life from a cross-national
and
comparative perspective. Recently the focus of this attention, particularly

within the European Union (EU), relates to one of the myths of modern times,

the devastation that will result because of the demographic time-bomb.
I was
pleased to see another refutation of this in Reynaud's article (p.
34). Thus the
framework for this European-wide discussion has been as much about
ideological and political issues as about economic ones, such as level
of public
provision of support in old age.These two articles approach the issue of income in later life from different

angles. The Reynaud article is essentially a review of the current debate
on
public pensions within the EU. It focuses upon the manner in which pension

policy has adapted to social and economic change in recent years. No
statistical or quantitative analysis is presented and this limits the analysis

somewhat. Shaver on the other hand adopts a classic quantitative approach,

using a well-established dataset, the Luxembourg Income Study (LIS), to

revisit the longstanding debate about the merits of universalism and selectivism

within the context of income in later life.
The least squares fit of a hyperplane to uncertain data
Authors: Reister David B. 
Published: July 2002

Sensor based robotic systems are an important emerging technology. When
robots are working in unknown or partially known environments, they need range
sensors that will measure the Cartesian coordinates of surfaces of objects in
their environment. Like any sensor, range sensors must be calibrated. The range
sensors can be calibrated by comparing a measured surface shape to a known
surface shape. The most simple surface is a plane and many physical objects have
planar surfaces. Thus, an important problem in the calibration of range sensors
is to find the best (least squares) fit of a plane to a set of 3D points. We have formulated a constrained optimization problem to determine the least
squares fit of a hyperplane to uncertain data. The first order necessary
conditions require the solution of an eigenvalue problem. We have shown that the
solution satisfies the second order conditions (the Hessian matrix is positive
definite). Thus, our solution satisfies the sufficient conditions for a local
minimum. We have performed numerical experiments that demonstrate that our
solution is superior to alternative methods.
THE EUROPEAN WAY TO HEALTH TECHNOLOGY ASSESSMENT
Authors: Sassi Franco 
Published: July 2002

Objectives: The EUR-ASSESS project was undertaken by a large
number of members of European health technology assessment (HTA) agencies and
programs with the aim of improving coordination through developments in
several areas of HTA. At the conclusion of the project, an independent survey
was undertaken to reassess the importance of the original objectives of
EUR-ASSESS and determine the impact of the project on the way HTA activities
are organized and carried out in Europe.Methods: A postal questionnaire survey and a series of more
in-depth personal interviews.Results: EUR-ASSESS was generally considered successful in
achieving its aims, particularly in creating an informal network of people and
organizations, improving the understanding of the work of others, improving
the ability to focus the objectives of HTA, facilitating the sharing of
experience and mutual learning opportunities, exchanging ideas on research
agendas, and developing a common language. However, significant differences
emerged in the expectations of different actors in European HTA, and in their
perceptions of the impact of the project. These reflect the wide diversity of
approaches existing in Europe.Conclusions: Health technology assessment in Europe is changing
its nature from a set of national or local initiatives with relatively limited
impact to a truly European movement with strong links and coordination between
its individual components. Important lessons can be learned from the
experience of EUR-ASSESS, particularly in the light of an increasing
commitment of the European Commission to play a role in the development of
technology assessment.
The German bourgeois club as a
political and social structure in the late
nineteenth and early twentieth centuries
Authors: HEILBRONNER ODED 
Published: July 2002

The German voluntary association (hereafter in German the Verein,
or
Vereine in the plural) played an important role in the evolution of German
society in the later nineteenth century and in the first third of the
twentieth. This sort of association (or male bourgeois club) was a
cornerstone of European Enlighenment society at the end of the eighteenth
century, of the liberal society of the Vormärz, and of the
German political
parties in the years 1848–1849. Furthermore, the Verein
was one of the
main characteristics in the rise and hegemony of German bourgeoisie in
the second half of the nineteenth century, and one of the cornerstones
of
local society as it developed in Germany towards the end of the 1890s.Research into the German Vereine is very advanced. To this
day,
historical research continues to benefit from Thomas Nipperdeys'
breakthrough article concerning the importance of the Vereine
in the rise
of bourgeois-liberal society prior to 1848. Otto Dann, Wolfgang
Hardtwig, and Dieter Düding have expanded our knowledge concerning
the importance of the Vereine for the rise of bourgeois nationalism
and
liberalism before 1848. Regional studies have also emphasized these
aspects during the Vormärz period and after.Folklorist-anthropological research is indebted to Hermann Bausinger's
article on the importance of the connection between the Vereine
and the
development of German folklore. Similarly, Max Weber paved the way
for the sociological research on the Vereine that has flourished
since the
1860s, led by sociologists such as Hans Jürgen Siewert and Gerhard
Wurzbacher. These are the two dominant streams in current research of
the Vereine, although it is beyond the scope of this article to
explore them
here.
Combinators for breadth-first search
Authors: SPIVEY MICHAEL 
Published: July 2002

Every functional programmer knows the technique of “replacing failure by a list of
successes” (Wadler, 1985), but wise programmers are aware also of the possibility
that the list will be empty or (worse) divergent. In fact, the “lists of successes”
technique is equivalent to the incomplete depth-first search strategy used in Prolog.At heart, the idea is quite simple: whenever we might want to use a ‘multi-function’ such as
‘f’ [ratio ][ratio ] α [Rarr ] β that can return many results or none, we replace it by a
genuine function f [ratio ][ratio ] α → β stream that returns a lazy stream of results, and
rely on lazy evaluation to compute the answers one at a time, and only as they are needed. For
the sake of clarity, I will distinguish between the types of finite lists (α list) and of
potentially infinite, lazy streams (α stream), though both may be implemented in the
same way. Following the conventions used in ML, type constructors follow their argument types.
Maximum marking problems
Authors: BIRD RICHARD S. 
Published: July 2002

Here are two puzzles for you to solve. First, consider the binary tree in figure 1.
Take a pencil (I am assuming that this is your personal copy of JFP!) and mark
some of the nodes in such a way that the sum of the values of marked nodes is
as large as possible. The catch is that you cannot mark all the nodes: if you mark
a node, then you are not allowed to mark its parent. Equivalently, no two marked
nodes can be contiguous in the tree.The second puzzle is similar though both the datatype and constraint are different.
Consider the rose tree of figure 2 (a rose tree is a tree with arbitrary branching
structure). Mark some of the nodes so that all marked nodes are now contiguous in
the tree. For example, if you mark the root value 4 and the leaf value 1, then you
must also mark the values 5 and −3 along the path from 4 to 1. Again the idea is
to maximise the sum of the marked nodes. Of course, if all values were nonnegative,
the best solution would be to mark all nodes. But they aren't and the maximum
sum is obtained only by a judicious choice of marking. Answers to both puzzles are
given at the end of the paper.The Maximum Marking Problem (MMP) is the problem of marking the entries
of some given data structure in such a way that a given constraint is satisfied and
the sum of the values associated with marked entries is as large as possible. By the
end of this pearl, you will be convinced that there is a linear-time solution for both
the puzzles described above.
Applications of Plotkin-terms:
partitions and morphisms for closed terms
Authors: STATMAN RICHARD , BARENDREGT HENK 
Published: July 2002

This theoretical pearl is about the closed term model of pure untyped lambda-terms modulo
β-convertibility. A consequence of one of the results is that for arbitrary distinct combinators
(closed lambda terms) M, M′, N, N′ there is a combinator H such thatformula hereThe general result, which comes from Statman (1998), is that uniformly r.e. partitions of the
combinators, such that each ‘block’ is closed under β-conversion, are of the form
{H−1{M}}M∈ΛΦ.
This is proved by making use of the idea behind the so-called Plotkin-terms, originally devised
to exhibit some global but non-uniform applicative behaviour. For expository reasons we
present the proof below. The following consequences are derived: a characterization of
morphisms and a counter-example to the perpendicular lines lemma for β-conversion.
Camelot – a database for climate model output
Authors: Gregory J M , Tett S F B , Hibling E L 
Published: July 2002

AbstractCamelot is a database system designed for output from the climate model run by the Hadley Centre of the UK Meteorological Office. It contains metadata for climate model output held in a tape archive and on the workstation system used for analysis. The system is required because of the large and rapidly growing volume of archive data and the great variety of uses of the climate model. Camelot enables the user to find out about what has been archived and to retrieve data selectively to the workstations with specifications given in terms of metadata rather than files, without recopying data already held online. The PV‐WAVE analysis environment used on the workstation system also allows the user to access the data by reference to its metadata. Copyright © 2000 Royal Meteorological Society
Mesoscale analysis of a comma cloud observed during FASTEX
Authors: Williams K D 
Published: July 2002

AbstractA cold‐air comma cloud crossed southern Britain early on 18 February 1997 bringing strong gusts and convective precipitation. Development of the comma cloud occurred in association with a positive upper tropospheric potential vorticity (PV) anomaly. A mesoscale analysis of the comma cloud was carried out using special three‐hourly soundings from UK radiosonde stations together with data from rainfall radar, satellite, NWP model output and a wind‐profiling radar. The analysis reveals that the comma cloud tail was of ana‐form whilst the polar cold front (behind which the comma cloud developed) was kata‐form. Further analysis indicates that the polar cold θw front and the comma cloud front were tending to become one entity at the surface and can thus be considered an example of a kata‐cold front undergoing a partial transition to more of an ana‐form locally in the region of an upper tropospheric positive PV anomaly. Copyright © 2000 Royal Meteorological Society
Characteristics of recent UK flood‐producing rainfalls in relation to the Flood Studies Report design event method
Authors: Faulkner D S 
Published: July 2002

AbstractWeather radar images were used in an investigation of the rainfall events which gave rise to various damaging UK floods in the 1990s. Radar data of sufficient quality were available for seven events from an initial list of 26. The relative temporal and spatial rainfall profiles of each event are displayed and summarised, along with the antecedent catchment wetnesses. Catchment rainfall totals were obtained from daily raingauges. These characteristics are compared with their equivalents in a standard method of flood estimation, the design event method of the Flood Studies Report. The results highlight the complexity of rainfall fields. The wide variety of event characteristics includes some large deviations from their counterparts in the design event. Six of the catchments were modelled with the design event method in order to assess the significance of the deviations in terms of the estimated flood peaks. The rainfall depth and duration and the antecedent catchment wetness were found to have a significant influence within the design event method. The temporal profile was of lesser importance, for most of the events studied. Copyright © 1997 Royal Meteorological Society