bluuebunny/crossref_metadata_2025 huggingface dataset:
A new parallel wrist using only revolute pairs: the 3-RUU

wrist
Authors: Di Gregorio Raffaele
Published: July 2002

Only one parallel wrist with three equal legs containing just revolute pairs has been already presented in the literature. This parallel wrist is overconstrained, i.e., it involves three degrees of freedom required to orientate the end effector by using repetitions of constraints. The overconstrained mechanisms have the drawback of jamming or undergoing high internal loads when geometric errors occur. This paper presents a new parallel wrist, named 3-RUU wrist. The 3-RUU wrist is not overconstrained. It has three equal legs just involving revolute pairs and actuators adjacent to the frame and uses an architecture (3-RUU) already employed to obtain manipulators that make the end effector translate. The 3-RUU wrist kinematic analysis is addressed. This analysis shows that the new parallel wrist can reach singular configurations (translation singularities) in which the spherical constraint between end effector and frame fails. The singularity condition that makes finding all the 3-RUU wrist singular configurations possible is written in explicit form and geometrically interpreted.
Bilateral teleoperation of mobile robots
Authors: Mut Vicente , Postigo José , Slawiñski Emanuel , Kuchen Benjamin
Published: July 2002

A control structure for the bilateral teleoperation of mobile robots, with tactile feedback and visual information of the interaction force is proposed in this paper. Also an impedance controller is implemented in the mobile robot structure that guarantees the linear velocity be within a desired fixed range without saturation in the actuators. To illustrate the performance of the proposed control structure, experiments on a Pioneer 2 mobile robot teleoperated with a commercial joystick with force feedback are shown.
Fast constrained global minimax optimization of robot parameters
Authors: Stocco L. , Salcudean S. E. , Sassani F.
Published: July 2002

A new global isotropy index (GII) is proposed to quantify the configuration independent isotropy of a robot's Jacobian or mass matrix. A new discrete
global optimization algorithm is also proposed to optimize either the GII or some local measure without placing any conditions on the objective function. The algorithm is used to establish design guidelines and a globally optimal architecture for a planar haptic
interface from both a kinematic and dynamic perspective and to choose the optimum geometry for a 6-DOF Stewart Platform. The algorithm demonstrates consistent effort reductons of up to six orders of magnitude over global searching with low sensitivity to initial
conditions.
Tracking adaptive impedance robot control with visual feedback
Authors: Mut Vicente , Nasisi Oscar , Carelli Ricardo , Kuchen Benjamin
Published: July 2002

In this paper we propose a tracking adaptive impedance controller for robots with visual feedback. It is based on a generalized impedance concept where the sensed distance is introduced as a fictitious force to the control in order to avoid obstacles in restricted motion tasks. The controller is designed to compensate for full non-linear robot dynamics. Robot parameters adjustment is introduced to reduce the sensibility of the controller design to dynamic uncertainties of the robot and the manipulated load. It is proved that the vision control errors are ultimately bounded in the image coordinate system. Simulations are carried out to evaluate the controller performance.
ON THE LOG PERIODOGRAM REGRESSION ESTIMATOR OF THE
MEMORY PARAMETER IN LONG MEMORY STOCHASTIC VOLATILITY MODELS
Authors: Deo Rohit S. , Hurvich Clifford M.
Published: July 2002

We consider semiparametric estimation of the memory parameter
in a long memory stochastic volatility model. We study
the estimator based on a log periodogram regression as
originally proposed by Geweke and Porter-Hudak (1983, Journal
of Time Series Analysis 4, 221–238). Expressions
for the asymptotic bias and variance of the estimator are
obtained, and the asymptotic distribution is shown to be
the same as that obtained in recent literature for a Gaussian
long memory series. The theoretical result does not require
omission of a block of frequencies near the origin. We
show that this ability to use the lowest frequencies is
particularly desirable in the context of the long memory
stochastic volatility model.
EDITOR'S TRIBUTE
Authors: Phillips Peter C.B.
Published: July 2002

Elizabeth Dolomont joined the Cowles Foundation as my secretary
in 1984 and retired in December 1997. Over the intervening 14 years,
Elizabeth has been my personal assistant at Yale in running the journal
Econometric Theory.
Types and causes of tree mortality in a tropical montane cloud forest of Tamaulipas, Mexico
Authors: Arriaga Laura
Published: July 2002

The types and causes of death of canopy and subcanopy trees were characterized for the tropical montane cloud forest of Tamaulipas, Mexico. Field work was carried out at the Biosphere Reserve ‘El Cielo’, located on the eastern slope of the Sierra Madre Oriental. Three study plots, each of 2 ha, were selected within the forest differing in their degree of exposure to wind. Results indicate that the tropical montane cloud forest presents a differential treefall regime derived from the great hurricane activity to which this mountain range is exposed. This effect is illustrated by the great number of fallen logs (545 trees in 6 ha) and the high percentage of uprooted (48.3%) and snapped off (37.6%) trees. Other treefall factors included the rocky and shallow soils and weakness of the dominant trees from insect attack. A differential disturbance level was obtained between zones. The disturbance was higher for the exposed zone, where the crown cover of emergent trees was not closed. Species composition of the dead material was related to the abundance of the overstorey species as standing vegetation. Ten of the 20 recorded species were able to sprout and just 7.5% of the 545 fallen trees were sprouting. Quercus germana, Q. sartorii, Clethra pringlei, Liquidambar styraciflua and Ceris canadensis, accounted for 78.5% of the gap-forming species. The type of treefall differed between species of the same genera: Q. germana was generally found uprooted, while Q. sartorii died standing probably because of previous weakening from dipterous insects.
Effects of native pigs (Sus scrofa) on woody understorey vegetation in a Malaysian lowland rain forest
Authors: ICKES KALAN , DEWALT SAARA J. , APPANAH S.
Published: July 2002

Large mammals often play important roles in determining the structure and composition of plant
communities. This study focused on the extent to which wild pigs (Sus scrofa) influence the dynamics of tree seedlings and
saplings in a lowland rain forest at Pasoh Forest Reserve in West Malaysia. Native wild pigs are common in the study
area and may significantly influence growth and survivorship of woody plants in the understorey through several
activities namely, nest building, soil rooting and seed predation. To test experimentally the impact of pigs on the
plant community, eight 49-m2 exclosures were constructed. After 2 y, the number of recruits inside exclosures was
three times greater than in unfenced control plots. Stem density was highly correlated with species richness, which
also increased significantly inside exclosures. Height growth of plants was greater in the exclosures by 52.5% for trees
between 1 and 7 m tall. Trees less than 1 m tall, however, exhibited no differences in growth. Mortality of plants also
did not differ between treatments. The observed differences between exclosure and control plots can be attributed to
soil-rooting and seed predation, suggesting that these two behaviours of wild pigs are important to plant dynamics in
the understorey.
Using fuzzy logic for autonomous robotics: an on-line workshop
Authors: SAFFIOTTI ALESSANDRO
Published: July 2002

In October 1995, Takeshi Furuhashi and his collegues at the Bio-Electronics Laboratory of Nagoya University, Japan, organized the first of a series of on-line workshops, held entirely on the World Wide Web. The advertised advantages of the on-line format were to allow fruitful exchanges while avoiding physical travel, and to guarantee wide visibility of the discussion. The first two workshops in the series were devoted to evolutionary computation; they can be accessed on the web at http://www.bioele.nuee.nagoya-u.ac.jp. The third workshop, named “First On-Line Workshop on Soft Computing” (WSC1), had a broader scope, including all the techniques that go under the heading of “soft computing”, like fuzzy logic, neuro computing, genetic computing, and so on. WSC1 took place from August 19 to 30 1996, and it is accessible on the web at http://www.bioele.nuee.nagoya-u.ac.jp/wsc1/. Because the declared goal of an on-line workshop is to prompt discussion, the rules for submission were looser than in most traditional workshops: papers were not subject to peer review, and it was possible to submit already published papers. All the submitted papers were made visible on the web one week before the workshop, and people could send comments and questions by email during the two workshop weeks; all the questions, comments, and authors' replies are also visible at the WSC1 web site.
Temporal Representation and Reasoning
Authors: MORRIS ROBERT , KHATIB LINA
Published: July 2002

Artificial intelligence research in temporal reasoning focuses on designing automated solutions to complex problems in computation involving time. TIME-97, the 4th International Workshop on Temporal Representation and Reasoning, held in Daytona Beach, Florida — like the three workshops that preceded it — had the objective of creating an international forum for the exchange of information among the many researchers and knowledge engineers who are developing and applying techniques in temporal reasoning.
An overview of regression techniques for knowledge discovery
Authors: UYSAL İLHAN , GÜVENIR H. ALTAY
Published: July 2002

Predicting or learning numeric features is called regression in the statistical literature, and it is the subject of research in both machine learning and statistics. This paper reviews the important techniques and algorithms for regression developed by both communities. Regression is important for many applications, since lots of real life problems can be modeled as regression problems. The review includes Locally Weighted Regression (LWR), rule-based regression, Projection Pursuit Regression (PPR), instance-based regression, Multivariate Adaptive Regression Splines (MARS) and recursive partitioning regression methods that induce regression trees (CART, RETIS and M5).
THE POWER OF BABEL: TEACHING AND LEARNING IN MULTILINGUAL
CLASSROOMS.Viv Edwards. Stoke-on-Trent, UK: Trentham Books, 1998.
Pp. 88. £11.95 paper.
Authors: Bayley Robert
Published: July 2002

As a result of large-scale migrations from the less developed to the more developed
countries, the multilingual, multicultural school is becoming a reality, not only in cities with
traditionally large immigrant populations such as New York, Los Angeles, and Toronto, but
throughout North America and Western Europe. Indeed, the 1990 U.S. Census shows that one in
every seven children between the ages of 5 and 17 comes from a home where a language other
than English is spoken. These major demographic changes have left many teachers and other
school personnel unprepared to deal with the new realities of the multilingual, multicultural
classroom. Edwards' brief volume is directed to mainstream classroom teachers who, if
current trends continue as expected, will spend much of their careers in even more linguistically
and culturally diverse schools than exist currently. Edwards' intent is to counter
widespread myths about second language learning and bilingualism, and to assist teachers
maximizing the rich educational resource that the multicultural, multilingual school
represents.
CONVERSATIONS OF THE MIND: THE USES OF JOURNAL WRITING FOR
SECOND-LANGUAGE LEARNERS. Rebecca Williams Mylnarczyk.
Mahwah, NJ: Erlbaum, 1998. Pp. xvi + 215. $49.95 cloth, $26.00 paper.
Authors: James Leon
Published: July 2002

This easy-to-read paperback is the result of the author's desire to learn more about
how students think and feel about themselves as learners in a “large urban college”
pre-freshman ESL composition class. It is intended for teachers, scholars, and graduate students
who are interested in how students learn to write as well as their accompanying thought
processes and emotions. The main body of the book, chapters 4–7, presents “case
studies of the journal writing experiences of five students” (p. 8) chosen to represent the
variety of cultural backgrounds and personal involvement with the freewriting process in journal
keeping. The students came from Colombia, Ethiopia, the Dominican Republic, People's
Republic of China, and Japan.
ALERTNESS, ORIENTATION, AND DETECTION
Authors: Simard Daphnée , Wong Wynne
Published: July 2002

This paper critically examines Tomlin and Villa's (1994) fine-grained analysis of
attention and Leow's (1998) attempt to operationalize their model. Our position is that
whereas Tomlin and Villa have moved the attention research forward by describing the nature of
attentional processes and by pointing out that detection is a critical function of SLA, their claim
that alertness and orientation are not necessary for detection to occur is currently unsupportable
and does not reflect the complex nature of SLA. We argue that Leow's efforts to provide
empirical support for this model fall short of that goal. Additionally, we cast doubt on Tomlin and
Villa's position that awareness is not required for the detection of L2 data by arguing that
the issue of awareness as well as the role of attentional functions must be viewed from a more
interactive perspective in terms of the nature of the task, the nature of the linguistic item, and
individual learner differences. We conclude by proposing research orientations that may help
advance the discussion on this topic.
RESEARCHING VOCABULARY THROUGH A WORD KNOWLEDGE
FRAMEWORK
Authors: Schmitt Norbert , Meara Paul
Published: July 2002

This study examines how two types of word knowledge, word associations and grammatical
suffix knowledge, change over time both receptively and productively. Ninety-five secondary and
postsecondary Japanese students were tested on three word associations and inflectional and
derivational suffixes for each of 20 verbs, once near the beginning of their academic year and
once near the end. The results showed their average vocabulary gain was 330 words. The
students showed rather poor knowledge of the allowable suffixes for the verbs, especially the
derivative suffixes. Likewise, the subjects did not show very good mastery of the verbs'
word associations. Even for verbs rated as known, the students as a group were able to produce
only about 50% of the word associations possible on the test as judged by native speaker norms.
Word association knowledge and suffix knowledge were shown to correlate with each other and
with total vocabulary size. The subjects overall had from 19 to 25 percentage points more
receptive knowledge than productive knowledge.
LANGUAGE CONTACT, LANGUAGE CONFLICT.Martin Pütz
(Ed.). Amsterdam: Benjamins, 1994. Pp. xv + 254. $59.00 cloth.
Authors: Knowles Mark
Published: July 2002

Language Contact, Language Conflict treats the increasingly common
phenomenon of language contact and the subsequent cultural influences that contact can entail.
The collection of papers is the result of a symposium held in Duisburg in March 1992 and is
divided into two sections: (a) theoretical linguistic issues and (b) case studies from throughout
the world. In the foreword, Hymes admits his skepticism toward the search for universals in
linguistics, cognition, and human nature when “so much of anger as of joy is in the
details” and, therefore, to preserve humanity, “the complex, emergent
configurations of particular languages and ways of life are what need to be understood and
shared” (foreword, no page number).
Acquisition of variable rules: a study of (-t, d) deletion

in preschool children
Authors: ROBERTS JULIE
Published: July 2002

The present study examined the pattern of deletion of final /t/

and /d/

in word final consonant clusters in sixteen three- and four-year-old

children and their degree of mastery of phonological and grammatical

constraints to answer the following questions: how and when is this

variable rule acquired, and how does its acquisition relate to the learning

of the categorical rule of past tense formation? Sixteen children were

tape recorded in their South Philadelphia day care centre. In addition,

eight of their mothers were interviewed in their homes for purposes of

comparison.

Results of the study revealed that children as young as three had, for

the most part, mastered the phonological constraints on (-t, d) deletion.

They matched the adult pattern including the constraint of following

pause disfavouring deletion, the only one that has been shown to vary

according to geographical dialect. The children also made a consistent

and adult-like distinction between the grammatical forms of monomorpheme

and weak past tense. Their high rate of deletion in semi-weak

verbs, which differs from adult patterns, suggests that the children are

demonstrating rule acquisition based on an analysis of verbal inflection.
Developmental changes and variability in the early
lexicon: a study of French children's naturalistic
productions
Authors: BASSANO DOMINIQUE , MAILLOCHON ISABELLE , EME ELSA
Published: July 2002

This paper investigates developmental changes, as well as inter-linguistic

and inter-individual variations, in the expansion and composition of
French children's early lexicons. Two studies were conducted using

children's naturalistic productions: a longitudinal study of one child

between 1;2 and 2;6, and a cross-sectional study of two groups (12
children each) aged 1;8 and 2;6. Analyses indicate that lexical productivity

(measured in types, tokens, and new words) strongly increased
with age, whereas lexical diversity showed almost no developmental
progression. Nouns and para-lexical elements (including interjections,

fillers or formulas) were predominant until 1;8 and decreased over time,

while predicates and grammatical words increased. As compared to
English, French development was characterized by less frequent nouns,
initially more frequent predicates, and a remarkable expansion of
grammatical words. Inter-individual variability in lexical productivity,

in lexical diversity, and in the proportions of different categories was

more marked at 1;8 than at 2;6. Lexical profiles found at 1;8 suggest the

existence of more diversified organizational patterns than those captured

in the referential-expressive distinction.
Predicting variation in the timing of language
milestones in the second year: an events history
approach
Authors: TAMIS-LEMONDA CATHERINE S. , BORNSTEIN MARC H. , KAHANA-KALMAN RONIT , BAUMWELL LISA , CYPHERS LISA
Published: July 2002

In a longitudinal investigation of 40 child–mother dyads,
we examined
prediction from three indexes of children's own language: (1) vocal

imitations, (2) first spontaneous words in production, and (3) receptive

language starting at 0;9, and their mothers' verbal responsiveness
at 0;9
and 1;1, to the developmental onset of three significant language
milestones of the second year: (1) 50 words in productive language, (2)

combinatorial speech, and (3) the use of language to express a memory.

In these analyses, we utilized EVENTS HISTORY ANALYSIS, a statistical

technique well suited to questions concerning when in development
certain events begin and the extent to which predictors influence the
timing of those events. The timing of children's first words in production,

the timing of their achievement of 50 words in receptive
language, and maternal responsiveness at 1;1 each contributed uniquely

to variation in the timing of the three language milestones. When child

and mother factors were considered together, the onset of the three
language milestones differed by as much as 0;5 months for children in
the lower and upper 10th percentiles of the predictor variables. The
present findings contribute to generating and testing specific models
about child and mother factors thought to explain variation in key
aspects of children's second-year language development.
Lattices in a split solvable Lie group
Authors: MOSAK RICHARD , MOSKOWITZ MARTIN
Published: July 2002

Given a Lie group, it is often useful to have a
parametrization of the set of its
lattices. In Euclidean space ℝn, for
example, each lattice corresponds to a basis, and
any lattice is equivalent to the standard integer lattice under an automorphism
in
GL(n, ℝ). In the nilpotent case, the lattices of the
Heisenberg groups are classified,
up to automorphisms, by certain sequences of positive integers with divisibility
conditions (see [1]). In this paper we will study the
set of lattices in a class of simply
connected, solvable, but not nilpotent groups G.
The construction of G depends on
a diagonal n×n matrix Δ
with distinct non-zero eigenvalues, of trace 0; we will write

formula here
Representation of families of sets by measures, dimension spectra
and Diophantine approximation
Authors: FALCONER K. J.
Published: July 2002

A family of sets {Fd}d
is said to be ‘represented by the measure μ’ if, for each
d, the set Fd comprises those points at
which the local dimension of μ takes some
specific value (depending on d). Finding the Hausdorff dimension of these sets may
then be thought of as finding the dimension spectrum, or multifractal spectrum, of μ.
This situation pertains surprisingly often, with many familiar families of sets
representable by measures which have simple dimension spectra. Examples are given from
Diophantine approximation, Kleinian groups and hyperbolic dynamical systems.
Effect of Path Prediction on Navigational Performance
Authors: van Breda Leo , Passenier Peter O.
Published: July 2002

A simulator experiment was conducted to determine the
potential benefits of path prediction
on the navigational performance of channel-bound vessels. Channel pilots
had to sail an
approach channel under critical conditions in a deep-draught vessel. For
the navigation task,
basic radar information was used, supplemented by three different path
predictors. Predictor
(a) was based on an accurate fast-time hydrodynamic model of the vessel
and showed the exact
future path of the vessel. Both other path predictors were less accurate,
relatively simple
extrapolators; predictor (b) was based on a speed and rate of turn extrapolator
and showed
a curved representation of the future path; predictor (c) was based on
a linear speed and
course extrapolator and showed the ground velocity vector. Navigational
performance was
determined in terms of deviation from the planned route. The results indicate
that the
relatively simple extrapolator (b) supported the navigational task as effectively
as the highly
accurate path predictor (a). In comparison with the linear extrapolator
(c), the navigational
accuracy increased by a factor of two. It is concluded
that support in anticipating the vessel's
rate of turn is essential for accurate navigation. Implications
of the use of path prediction for ship control are discussed.
The Status, Development and Future Role of Radiobeacon Differential
GNSS
Authors: Ward N.
Published: July 2002

Marine radiobeacons have been used to broadcast differential
corrections for global navigation
satellite systems (DGNSS) for nearly a decade. The method has
become the accepted
international standard for maritime applications. The background to the
development of the
system is described and the current status of radiobeacon
DGNSS services around the world
reported. The applications are discussed, including the
function of radiobeacon DGNSS as the
position sensor within integrated systems, together with the performance
requirements
imposed by associated systems such as ECDIS and Automatic
Identification
Systems. The
advantages and disadvantages of the radiobeacon system in regulatory, administrative
and
technical terms are discussed and the potential for development of the
system is considered.
The future role of radiobeacon DGNSS in the overall
mix of systems is assessed taking into
account the introduction of geo-stationary overlays, and possibly Loran-C,
for provision of
DGNSS corrections.
The Efficiency of the Greek Lighthouse Network
Authors: Englesou Julia , Lekakou Mary , Tzannatos Ernest
Published: July 2002

Among the many primary causes which lead to a shipping casualty,
those of wrecking,
stranding or coming into contact with fixed coastal structures depend (although
not exclusively
and only under specific conditions of visibility) upon the efficiency of
the lighthouse and
navigating lights network of a national coastline. The analysis of the
shipping casualties
involving Greek ships in the Greek seas revealed that, despite the recent
introduction of
sophisticated navigating aids for the prevention of stranding and contact,
the share of the
corresponding casualties remains unchanged. It appears that for coastal
shipping operations,
and in particular for port approaches, the traditional light navigating
aids are and will always
provide an irreplaceable safety service for navigators. This is mainly
attributed to their
technological simplicity which offers a high level of signal reliability
and
friendliness for the navigator.
Waypoint Navigation for Rivercraft?
Authors: Breedveld D.
Published: July 2002

Anticipating that transport on the West European inland
waterways will increase in volume,
in ship size and in speed, experiments are being carried out to investigate
whether safety of
navigation – including traffic management – can be improved
by the employment of GPS or
DGPS, electronic navigation charts, river radar and computer technology.
Although
waypoint navigation and collision avoidance systems are generally accepted
in the maritime
world, these methods could cause problems when applied on inland waterways.
Analysis of Self-Organising Radio
Systems for Position Reporting
Authors: Ann Ulrich , Kügler Dirk , Rohling Hermann
Published: July 2002

Self-organising radio systems have been proposed for aeronautical and maritime
communication, navigation and surveillance applications. In aviation, the introduction of
the VHF Data Link (VDL) Mode 4 is currently being discussed, while the implementation
of Automatic Identification Systems (AIS) is planned in the maritime domain. Operating in
an autonomous mode, a self-organising radio system employing Time Division Multiple
Access (TDMA) does not require a terrestrial infrastructure, such as base stations. The
concept of self-organisation is based on the cooperative behaviour of a large number of users
sharing a common VHF radio channel. Analyses have shown that uncoordinated stations,
so-called hidden users, can cause interference in self-organising radio systems. This paper
presents two different approaches to autonomous self-organisation together with the results
of investigations of intra-system interference. Such analyses may help to introduce potential
improvements to the system performance, which reduce the effect of hidden users in this very
promising GNSS-based technology.
Predicting Solar Disturbance Effects
on Navigation Systems
Authors: Lockwood M. , Wild M. N. , Stamper R. , Davis C. J. , Grande M.
Published: July 2002

A variety of operational systems are vulnerable to disruption by solar disturbances brought
to the Earth by the solar wind. Of particular importance to navigation systems are energetic
charged particles which can generate temporary malfunctions and permanent damage in
satellites. Modern spacecraft technology may prove to be particularly at risk during the next
maximum of the solar cycle. In addition, the associated ionospheric disturbances cause phase
shifts of transionospheric and ionosphere-reflected signals, giving positioning errors and loss
of signal for GPS and Loran-C positioning systems and for over-the-horizon radars. We now
have sufficient understanding of the solar wind, and how it interacts with the Earth's
magnetic field, to predict statistically the likely effects on operational systems over the next
solar cycle. We also have a number of advanced ways of detecting and tracking these
disturbances through space but we cannot, as yet, provide accurate forecasts of individual
disturbances that could be used to protect satellites and to correct errors. In addition, we
have recently discovered long-term changes in the Sun, which mean that the number and
severity of the disturbances to operational systems are increasing.
Application of Satellite Based
Augmentation Systems to Altitude
Separation
Authors: Magny Jean Pierre
Published: July 2002

This paper presents the application of GNSS1, or more precisely of Satellite Based
Augmentation Systems (SBAS), to vertical separation for en-route, approach and landing
operations. Potential improvements in terms of operational benefit and of safety are
described for two main applications. First, vertical separation between en-route aircraft,
which requires a system available across wide areas. SBAS (EGNOS, WAAS, and MSAS)
are very well suited for this purpose before GNSS2 becomes available. And secondly, vertical
separation from the ground during approach and landing, for which preliminary design
principles of instrument approach procedures and safety issues are presented. Approach and
landing phases are the subject of discussions within ICAO GNSS-P. En-route phases have
been listed as GNSS-P future work and by RTCA for development of new equipments.
Human Factors in Vector Map
Design: The Importance of Task-Display Dependence
Authors: Wickens Christopher D.
Published: July 2002

This paper, and the following 5 papers, were first presented at a Symposium on ‘Advanced
Moving-Map Displays’ held on the 3rd and 4th of August 1999 at the US Naval Research
Laboratory Detachment at the NASA Stennis Space Centre, Mississippi and are reproduced
in modified form with the kind permission of the NRL Commanding Officer, Captain
Douglas H. Rau USN.

The role of human factors in map design is to serve as a mediator between the technology
availed by electronic digital maps (particularly vector maps) on the one hand, and the many
tasks performed by the user on the other. Simply put, no one map is best suited for all tasks.
The appropriate mapping of map to task is, in turn, mediated by a series of information
processing principles, articulated by the engineering psychologist. The field is on the
threshold of being able to provide computational models, based on these principles, that will
provide guidance to the map designer as to the circumstances that make one map format
better than another for a particular application. This paper describes these principles as
applied to two domains of vector map design: the domain of three-dimensional maps, and
the domain of database overlay.
The Convention on Biological Diversity: exposing the flawed foundations
Authors: GURUSWAMY LAKSHMAN D.
Published: July 2002

Over five years have elapsed since the coming into force of the much heralded United Nations Convention on Biological Diversity (CBD or Convention) signed during the 'Earth Summit' at Rio de Janeiro in June 1992 (CBD 1992). Despite the warm, even euphoric welcome extended to this treaty by the environmental community, the difficulties of implementing the CBD in the last five years are unmasking and uncovering its flawed environmental foundations. The language of any legal instrument embodies and expresses the considered intentions of its creators, and may contain obligatory provisions that are legally binding. They may also contain hortatory and aspirational commitments that are not legally enforceable. The CBD rejected 'hard' environmental obligations that are legally binding for non-legal exhortations, and highly qualified 'soft' commitments. Whatever their value be as face-saving strategies for reaching agreement on the CBD, such aspirational expressions do not create a stable foundation for tough decisions in the world of realpolitik.
Confidential Awards Committee: ‘Best Paper’ Prizes for 1998
Authors: POLUNIN NICHOLAS V.C.
Published: July 2002

The Confidential Awards Committee voted Carolyn Crook and Roger Alex Clapp the joint recipients of the Volume 25 ‘Best Paper’ Prize for their paper ‘Is market-oriented forest conservation a contradiction in terms?’ (Crook & Clapp 1998). Their prize was a cheque for SFr 1000, the proceeds being shared between the co-authors.
A case similarity metric for software reuse and design
Authors: GOMES PAULO , BENTO CARLOS
Published: July 2002

When the idea of software reuse appeared in 1968,
new horizons for software design were open. But some major
problems appeared and most of the expectations were not
met. One of the problems encountered is the selection of
the right software component. This is related not only
to the similarity between the desired functionality and
the function delivered by the retrieved software component,
but also to the effort needed to modify the chosen component
to accommodate the desired functionality. Most of the research
done in the case-based reasoning area has been in developing
accurate and efficient retrieval algorithms. We think that
case-based reasoning retrieval concepts and ideas can be
successfully applied to software reuse. In this article
we propose a metric to assess similarity between software
cases supported on functional and behavioral knowledge.
One important aspect of this metric is that reusability
is taken into account to estimate the amount of effort
needed to reuse retrieved software cases. We also present
experimental work that shows that similarity at the functional
level is the most important aspect of the similarity metric
proposed.
Genotype analysis of human blood isolates of Campylobacter

jejuni in England and Wales
Authors: JACKSON C. J. , FOX A. J. , WAREING D. R. A. , SUTCLIFFE E. M. , JONES D. M.
Published: July 2002

Genomic profiles were obtained for 76 strains of Campylobacter

jejuni isolated from bacteraemic patients in England and Wales over
the

period 1981–94. Genotyping was

performed by restriction fragment length polymorphism (RFLP) analysis using
a random

cloned DNA probe, and by ribotyping with a PCR-generated C. jejuni
16S

ribosomal DNA

probe. Phenotypic characterization was achieved by heat-stable (HS) and

heat-labile (HL)

serogrouping, and Preston phagetyping and biotyping. The blood isolates
were

genomically

heterogenous, with 24 RFLP/16S profiles occurring within the 76 strains.

Forty-four percent of

isolates belonged to one of three RFLP/16S genotypes, reflecting the
patterns

seen in faecal

isolates, except that genotypes usually associated with the HS 1 antigen
were

uncommon. The

two most prevalent genotypes, characteristic of HS 2 and HS 4 strains,
showed

similarity by

cluster analysis. Further evidence was seen of associations between phenotypic

and genotypic

characters within some HS serogroups. Chromosomal profiling by RFLP analysis
does

not indicate that particular genotypes have a predisposition to invade

the bloodstream.
Comparative study of Mycobacterium paratuberculosis strains
isolated from Crohn's disease and Johne's disease using
restriction fragment length polymorphism and arbitrarily
primed polymerase chain reaction
Authors: FRANÇOIS B. , KRISHNAMOORTHY R. , ELION J.
Published: July 2002

To obtain insights into the pathogenic mechanisms involving Mycobacterium
paratuberculosis in
Crohn's disease (CD) we questioned if the strains of M.
paratuberculosis isolated from CD are
distinguishable from those involved in Johne's disease (JD), a chronic
granulomatous enteritis
in cattle. Accordingly we compared human and animal strains at the DNA level,
both by the
analysis of restriction fragment length polymorphism (RFLP) in and around
the insertion
sequence IS 900 and by the arbitrarily primed polymerase chain reaction
(AP-PCR). Results
are in favour of a common clonal origin for the 4 strains isolated
from CD and for 8 of the 11
strains isolated from cattle and sheep JD.
Molecular epidemiology of glycopeptide-resistant

Enterococcus faecium on a renal unit
Authors: CHADWICK P. R. , FOX A. , WOODFORD N.
Published: July 2002

The clinical and molecular epidemiology of glycopeptide-resistant

Enterococcus faecium was

investigated during an outbreak on a renal unit. Forty-nine patients were

colonized or infected

during a 15-month period. Sites of colonization included faeces, urine,

intravenous (IV)

catheter tips and wound swabs. Ten patients had infections, which included

five bacteraemias

and three episodes of peritonitis. Pulsed-field gel electrophoresis of

43 patient isolates of

glycopeptide-resistant E. faecium identified seven strains during

the first 7 months of the

outbreak. Three of these strains affected five or more patients. One

strain accounted for 17/43

isolates. Isolates that were possibly related to another renal unit

strain were cultured from

patients at two other Manchester hospitals. These isolates were

epidemiologically-related, and

may represent a single Manchester epidemic strain. Of five patients who

had multiple isolates

of glycopeptide-resistant E. faecium, three had isolates

representing a single strain and two

were colonized or infected by more than one strain.
A variant of variola virus, characterized by changes in
polypeptide and endonuclease profiles
Authors: DUMBELL K. R. , HARPER L. , BUCHAN A. , DOUGLASS N. J. , BEDSON H. S.
Published: July 2002

A variant of variola virus is described which produces a late polypeptide of 25 kDa instead of
one of 27 kDa and which has an additional endonuclease cleavage site for SalI in the viral
DNA. These markers were shown to be genetically independent and to characterize 14 of the
48 variola strains which were examined. The variant strains were isolated from smallpox
outbreaks originating in or from Pakistan between 1961 and 1974 and also from two cases at a
Mission Hospital in Vellore, India in 1964. No variant strains were found among 9 other
isolates from cases of variola major occurring in other parts of India or in Bangladesh, nor
among 4 isolates from Indonesia, 15 from Africa or 6 isolates of variola minor.
The potential of Latent Class Analysis in diagnostic test
validation for canine Leishmania infantum infection
Authors: BOELAERT M. , AOUN K. , LIINEV J. , GOETGHEBEUR E. , VAN DER STUYFT P.
Published: July 2002

Accuracy assessment of diagnostic tests may be seriously biased if an imperfect reference test is
used such as parasitology in the diagnosis of visceral leishmaniasis. We compared classical
validity analysis of serological tests for Leishmania infantum with Latent Class Analysis (LCA),
to assess whether it circumvented the gold standard problem. Clinical status, three serological
tests (IFAT, ELISA and DAT) and parasitological data were recorded for 151 dogs captured
in an endemic area. Sensitivity and specificity estimates from the 2×2 contingency tables were
broadly corroborated by LCA, but the latter method provided more precise estimates that were
robust for the different fitted models. It furthermore yielded a higher prevalence of infection
and indicated that parasitology was only 55% sensitive. LCA seems a promising technique for
test validation, but caution is required when applying it to sparse data sets. The feasibility and
applicability of LCA in infectious disease epidemiology is discussed.
Contaminated drinking water in one town manifesting as an
outbreak of cryptosporidiosis in another
Authors: McANULTY J. M. , KEENE W. E. , LELAND D. , HOESLY F. , HINDS B. , STEVENS G. , FLEMING D. W.
Published: July 2002

In early 1992 we identified an outbreak of cryptosporidiosis in Oregon and sought to identify
and control its source. We used a series of studies to identify risk factors for illness : (i) a case-control study among employees of a long-term-care facility (LTCF); (ii) a matched case-control
study of the general community; (iii) a cohort study of wedding attendees; and (iv) a cross-sectional survey of the general community. Drinking Talent water was associated with illness in
the LTCF (OR = 22·7, 95% CI = 2·7–1009·0), and in the community (matched OR = 9·5, 95%
CI 2·3–84·1). Drinking Talent water was associated with illness only among non-Talent
residents who attended the wedding (P < 0·001) and in the community (RR = 6·5, 95% CI
3·3–12·9). The outbreak was caused by contaminated municipal water from Talent in the
absence of a discernible outbreak among Talent residents, suggesting persons exposed to
contaminated water may develop immunity to cryptosporidiosis.
Claw retraction and protraction in the Carnivora: the cheetah (Acinonyx jubatus) as an atypical felid
Authors: Russell Anthony P. , Bryant Harold N.
Published: July 2002

The cheetah Acinonyx jubatus is the most cursorial felid and has been described as somewhat dog‐like in both the shape and the diminished degree of retraction of the claws. In this study we evaluate and investigate the osteological correlates associated with claw retraction in the cheetah through a comparison of the morphology of its middle phalanges with those of other felids and of the wolf Canis lupus. Compared to other felids, the middle phalanges of the cheetah have better‐developed grooving of the distal articulatory facets in both the manus and pes, reduced to absent angulation to the distal articulatory facets in the inner and outer digits, less marked asymmetry of the shaft, and a mid‐shaft cross‐section that is less triangular and more circular. In all of these features, the morphology of the cheetah is intermediate between that of other felids and that of the wolf. The cheetah's distinctive morphology is autapomorphic within Felidae and similarities between the cheetah and the wolf are the result of convergence. Study of an ontogenetic series of specimens of the domestic cat suggests that the morphology of the cheetah can be explained, at least in part, as a product of heterochrony in which the development of the middle phalanx is truncated at an earlier stage than is typical of the adults of other felids. Some of the morphological differences in the middle phalanges of the cheetah can be associated with its distinctive hunting behaviour. The reduced manipulative capabilities of the forelimb associated with the evolution of cursorial adaptations seem to have limited the roles of the forepaws in both the subduing of prey and feeding.
Acoustic identification of insectivorous bats (order Chiroptera) of Yucatan, Mexico
Authors: Rydell J. , Arita H. T. , Santos M. , Granados J.
Published: July 2002

The echolocation calls of insectivorous bats of the northern Yucatan Peninsula, Mexico, with the exception of the phyllostomids and molossids, are presented. The aim is to provide a catalogue of bat sounds that can be used for acoustic inventories of insectivorous bats using the Pettersson heterodyne and time‐expansion bat detectors. The acoustic method can be used alone or in combination with inventories based on mist‐netting, a method more suitable for the low‐intensity echolocators (mainly the phyllostomids), which are difficult to monitor acoustically. The insectivorous species of the Yucatan are generally easy to identify by their echolocation calls, particularly when combined with visual observations of foraging bats at dusk.
Directionality in linguistic change and acquisition
Authors: Gomes Christina Abreu
Published: July 2002

This article focuses on the directionality observed
in the processes of change and acquisition of the prepositions
that replaced Latin cases in the speech of Rio de Janeiro
and in the Contact Portuguese spoken by Brazilian Indians
in the region of Xingu. In Brazilian Portuguese, it is
possible to delete the indirect case preposition of some
verbs. The system loses and maintains prepositional nexus
in a cyclic process motivated by the semantic transparency
and the iconicity of the preposition, the adjacency between
verb and complement, and the degree of transitivity of
the verb. The variable use in Contact Portuguese shows
the same effects observed in the Rio de Janeiro variety,
in a process that includes a gradual filling up of categorical
and variable contexts. We argue that the forces that guide
acquisition of the Portuguese prepositional subsystem in
the Xingu variety act in the same way as those that constrain
variation in urban language.
Editorial: Stress and development: Biological and psychological consequences
Authors: CICCHETTI DANTE , WALKER ELAINE F.
Published: July 2002

This Special Issue of Development and Psychopathology is devoted to the
psychological and biological consequences of stress across the developmental course.
Contributions in this Special Issue address topics that are central to elucidating the impact that
stress exerts on developmental outcomes. These issues are investigated through examining a
diverse array of populations, including rodent and nonhuman primate samples, as well as cohorts
of maltreated children and adolescents with and without posttraumatic stress disorder (PTSD),
children who were adopted from Romanian orphanages at differing points during infancy, aging
Holocaust survivors and their offspring, children with depressive disorder, adolescents with
schizotypal personality disorder, and adults with bipolar and unipolar mood disorders.
Propagation of fronts in a nonlinear fourth order equation
Authors: LORETI P. , MARCH R.
Published: July 2002

We consider a geometric motion associated with the minimization of a curvature dependent
functional, which is related to the Willmore functional. Such a functional arises in connection
with the image segmentation problem in computer vision theory. We show by using formal
asymptotics that the geometric motion can be approximated by the evolution of the zero
level set of the solution of a nonlinear fourth-order equation related to the Cahn–Hilliard
and Allen–Cahn equations.
FUNCTIONAL PEARL On building trees with minimum height
Authors: BIRD RICHARD S.
Published: July 2002

A common solution to the problem of handling list indexing efficiently

in a functional

program is to build a binary tree. The tree has the given list as frontier
and is of

minimum height. Each internal node of the tree stores size information
(actually,

the size of its left subtree) to direct the search for an element at a
given position

in the frontier. One application was considered in my previous pearl (Bird,
1997).

There are two complementary methods for building such a tree, both of which
can

be implemented in linear time. One method is ‘recursive’,

or top down, and works

by splitting the list into two equal halves, recursively building a tree

for each half, and then combining the two results. The other method is

‘iterative’, or bottom up,

and works by first creating a list of singleton trees, and then

repeatedly combining

the trees in pairs until just one tree remains. The two methods lead

to different trees,

but in each case the result is a tree with smallest possible height.