bluuebunny/crossref_metadata_2025 huggingface dataset:
The ‘Daring Experiment’: The London County Council and the Discharge from Care of Children to Ireland in the 1950s and 1960s
Authors: GARRETT PAUL MICHAEL
Published: February 2003

This article examines the activities of the Children's Committee of the London County Council (LCC) and what a contemporary newspaper referred to as a ‘daring experiment’: its efforts to discharge children from public care to Ireland in the 1950s and 1960s. Archival evidence reveals how Irish children were identified and separated from English children in care and, in many instances, sent to Ireland. It is maintained the dominant constructions of ‘Ireland’ played a role in the scheme. In addition, the LCC policy is examined and viewed in the context of other exclusionary practices centred on Irish people in Britain in the mid-twentieth century.
Welfare State Policy and Informal Long-Term Care Giving in Austria: Old Gender Divisions and New Stratification Processes Among Women
Authors: HAMMER ELISABETH , ÖSTERLE AUGUST
Published: February 2003

In Austria, the provision of long-term care is strongly based on unpaid female work within family networks and is characterised by a highly unequal division of informal long-term care-giving. In 1993, a major reform has been introduced in the Austrian long-term care system with a payments for care programme and a state–provinces treaty regarding service development at its heart. The objective of this article is to investigate the implications of the 1993 programme on gender divisions and on whether and in what ways the programme and processes set in train by the programme influence the role of women as carers. The question is approached by applying and broadening the concept of defamilisation in a process oriented way. The analysis suggests that from the informal carers' perspective long-term care allowances in the Austrian context mean some financial relief via ‘symbolic payments’. At the same time, the overall long-term care system prolongs existing gender divisions and sets in train new stratification processes among women as main carers with gender, class and space as dimensions reinforcing each other.
A Social Policy Role for Faith-Based Organisations? Lessons from the UK Jewish Voluntary Sector
Authors: HARRIS MARGARET , HALFPENNY PETER , ROCHESTER COLIN
Published: February 2003

After two decades of growing expectations that the UK voluntary (or ‘third’) sector will expand its social policy role, the spotlight is now focusing on specific types of voluntary organisations including community groups, black and minority ethnic associations and ‘faith-based organisations’. This article notes the growing cross-party interest in the UK in religious organisations and then presents findings from two recent empirical studies of the UK Jewish voluntary sector; one on financial resources and the other on governance. We discuss the implications of our findings for a possible expanded social policy role for faith-based organisations in the UK.
Trainee clinical psychologists' views on recruitment to work with older people
Authors: LEE KRISTINA , VOLANS P. JANE , GREGORY NICOLA
Published: February 2003

For some time in Britain, it has been difficult to recruit clinical psychologists and other health professionals to work with older people. This pattern of under-recruitment has also been reported in other countries. With the growing number of older people in western societies, the issue of under-recruitment warrants further attention. This research reported here aimed to explore this issue among the next generation of clinical psychologists: those currently training. Questionnaires were posted to 25 of the clinical psychology training courses in the United Kingdom, and 371 trainees returned questionnaires. Among the questions posed, the trainees were asked to set down their thoughts as to why it might be difficult to recruit to the older adult specialty and how recruitment could be improved. The results suggest that many trainees believe that clinical psychology, despite many recent advances, has less to offer older people than other age groups. The responses contain evidence of both ageism and the fear of ageing and death. To improve recruitment into the older adult specialty of clinical psychology, the predominant recommendations were for good quality placements and teaching during training, as well as a need for improved marketing by clinical psychologists working in this specialty, and also for improved support, terms and conditions.
Interactions between care-giving and paid work hours among European midlife women, 1994 to 1996
Authors: SPIESS C. KATHARINA , SCHNEIDER A. ULRIKE
Published: February 2003

This paper uses data from the European Community Household Panel surveys of 1994 and 1996 to study the association between changes in care-giving and changes in weekly work hours. Our sample comprises women aged 45–59 years who participated in the labour force in at least one of the two years studied. Controlling for country variation, we find significant relationships between starting or increasing informal care-giving and changes in weekly work hours. No such association is found however among women terminating a care-giving commitment or reducing their care hours. Starting care-giving significantly reduces work hours for women in northern European countries (except Ireland). By contrast, women in southern Europe and Ireland respond to an increase in care-giving hours by a smaller increase or a higher decrease in work hours than non care-givers. In summary, our results show that the impact of care-giving on adjustments of weekly work hours is asymmetrical and that it differs in southern and northern Europe.
Age, labour market conditions and male suicide rates in selected countries
Authors: TAYLOR PHILIP
Published: February 2003

This study examined the relationship between suicide rates among men since 1975 and rates of unemployment and labour force participation in 20 countries. Previous research has found statistically significant correlations between suicide and unemployment rates over time among young people in a number of countries. This study has extended this research to include different age groups of men. The findings for younger workers largely confirm the findings of previous studies. Among older workers, however, unemployment and suicide rates are largely unrelated, notable exceptions including Japan and the USA. The implications of this finding for policy making towards older workers are discussed.
Men's organisational affiliations in later life: the influence of social class and marital status on informal group membership
Authors: PERREN KIM , ARBER SARA , DAVIDSON KATE
Published: February 2003

This paper considers a dimension of social life that has been largely neglected in the research literature on ageing, older men's involvement with informal associations. These affiliations represent an under-valued resource which may contribute to the quality of life of older men by facilitating social interaction and providing a context for continued social productivity. Using the British Household Panel Survey for 1999, we explore the engagement of men aged 65 or more years with civic groups (such as political parties or voluntary agencies), religious organisations, and sports and social clubs. Involvement in civic and religious groups and sports clubs is common among middle class older men, while social club membership is common among working class men. Only a small amount of these differences can be explained by variations in health, income and access to private transport. Compared with partnered older men, widowers are more likely to be involved with sports and social clubs, while men who are divorced or never married are less likely to be a member of any informal group.
Meaningful social interactions between older people in institutional care settings
Authors: HUBBARD GILL , TESTER SUSAN , DOWNS MURNA G.
Published: February 2003

This paper is a contribution to the developing understanding of social relationships in institutional care settings. It focuses on two areas that have been neglected in research: the reasons for and types of social interaction in institutional settings, and the ways in which the context of people's lives shapes social interaction. The paper draws on ethnographic observations conducted in four care settings in Scotland using a symbolic interactionist perspective. It finds that residents communicate and interact, and that the personal, cultural and structural contexts frame social interaction and influence the ways that residents use humour, express sexuality, and show hostility. The paper concludes that residents create social interactions in which action is embedded, but do so within specific structural and cultural contexts. These contexts ‘control’ resident action by establishing frameworks for the interpretation of meaning. At the same time, each facet of context is ‘controlled’ by the ways in which residents actively take on the ‘role’ of others, and project ‘self’ and a ‘label’.
Experimental evaluation of a model reference adaptive control for a
hydraulic robot: a case study
Authors: Kireçci Ali , Topalbekiroglu Mehmet , Eker İlyas
Published: February 2003

This paper presents the implementation of an explicit model reference adaptive control (MRAC) for position tracking of a dynamically unknown robot. An auto regressive exogenous (ARX) model is chosen to define the plant model and the control input is optimised in a H2 norm to reduce computational time and to simplify the algorithm. The theory of MRAC falls into a description of the various forms of controllers and parameter estimation techniques, therefore, applications may require very complicated solution methods depending on the selected laws. However, in this study, the proposed MRAC shows that applications may be as easy as classical control methods, such as PID, by guaranteeing
the stability and achieving the convergency of the plant parameters. Despite the selected simple control model, simple optimisation method and drawbacks of the robot the experimental results show that MRAC
provides an excellent position tracking compared with conventional control (PID). Many experimental implementations have been done on the robot and one of them is included in the paper.
Path planning by fractional differentiation
Authors: Oustaloup A. , Orsoni B. , Melchior P. , Linarès H.
Published: February 2003

In path planning design, potential fields can introduce force constraints to ensure curvature continuity of trajectories and thus facilitate path-tracking design. The parametric thrift of fractional potentials permits smooth variations of the potential in function of the distance to obstacles without requiring design of geometric charge distribution. In the approach we use, the fractional order of differentiation is the risk coefficient associated to obstacles. A convex danger map towards a target and a convex geodesic distance map are defined. Real-time computation can also lead to the shortest minimum danger trajectory, or to the least dangerous of minimum length trajectories.
Navigation of multiple mobile robots using a neural network and
a Petri Net model
Authors: Pham D.T. , Parhi Dayal R.
Published: February 2003

This paper describes the use of a hybrid system comprising a multi-layer perceptron and a Petri Net model to control the navigation of multiple mobile robots in an
unknown and cluttered environment. The multi-layer perceptron is trained with examples representing the typical static obstacles to be encountered by the robots and the evasive actions to be taken. The Petri Net model embodies the rules describing how the robots should
move in order to avoid colliding against one another. The hybrid system has been implemented in simulation software as well as in actual mobile robots. The paper presents the results
of simulation and practical tests that demonstrate the ability of groups of robots incorporating the proposed navigation system to negotiate various types of obstacles and find targets successfully.
Control of foot placement, forward velocity and body orientation of a one-legged hopping robot
Authors: Vermeulen J. , Lefeber D. , Verrelst B.
Published: February 2003

This paper intends to contribute to the study of dynamically balanced legged robots. A real-time applicable control algorithm for a planar one-legged robot is developed, which allows for locomotion on an irregular terrain. The simulated model consists of an articulated leg and a body, vertically placed upon the leg. During the stance phase the leg is supported by a massless foot. The algorithm is based on the choice of a number of objective locomotion parameters which can be changed from one hop to another. From a
chosen initial configuration the robot is able to transfer to a chosen end configuration, while simultaneously controlling its forward velocity, its step length and its stepping height. The foot is thus being placed exactly on a chosen foothold. To reach this goal, the actuators track polynomial functions. The calculation of these functions is based on the objective parameters, and takes into account the constraints acting on the robot. These constraints
result from the fact that during flight the center of gravity of the robot tracks a parabolic trajectory, and that the angular momentum with respect to the center of gravity is conserved. Writing the angular momentum constraint in a Caplygin form is the key to the algorithm. Promising simulation results for the algorithm are shown for two different experiments.
Introduction
Authors: Harwin William , Hillman Michael
Published: February 2003

The four papers encompassing this special section on Robot Mediated Neuro-motor Therapy introduce a new area for robotics in the healthcare industry, that of
assisting in the delivery of neuro-motor therapies, for patients recovering from a stroke. As life expectancy increases, so do problems associated with old age. In the paper by Krebs et
al. the authors not only summarise the need for action in stroke rehabilitation but also makes a useful distinction between assistive technologies that provide enhanced abilities for the patient, and therapy tools for the clinician, that seek to enhance the patients recovery.
Robotic applications in neuromotor rehabilitation
Authors: Krebs H.I. , Volpe B.T. , Aisen M.L. , Hening W. , Adamovich S. , Poizner H. , Subrahmanyan K. , Hogan N.
Published: February 2003

Robot-aids or Rehabilitators are our chosen neologism to name a new class of robotic devices that represent a substantially departure from prior applications of robotics in rehabilitation. Rather than use robotics as an assistive technology for a disabled individual, we envision robots and computers as supporting and enhancing the productivity of clinicians in their efforts to facilitate a disabled individual's recovery. In this paper, we attempt a brief overview of our work in what promises to be a ground breaking field. We discuss the concept of robot-aided neuro-rehabilitation as a means to deliver therapy, measure patient performance, and also as a design tool. To illustrate the broad spectrum of
neurological diseases that this technology might impact, we will illustrate each case with a different pathology, namely cerebral vascular accident (CVA – also known as stroke), Parkinson's disease (PD), and cerebral palsy (CP).
Design and evaluation of Driver's SEAT: A car steering simulation
environment for upper limb stroke therapy
Authors: Johnson M. J. , Van der Loos H. F. M. , Burgar C. G. , Shor P. , Leifer L. J.
Published: February 2003

Hemiplegia, affecting approximately 75% of all stroke survivors, is a common neurological impairment that results in upper and lower limb sensory and motor deficits. Recovery of coordinated movement of both upper limbs is important for bilateral
function and promotes personal independence. This paper describes the philosophy and design of Driver's Simulation Environment for Arm Therapy, a one-degree-of-freedom robotic device that uses a modified Constraint-Induced therapy paradigm to promote coordinated bilateral movement in the upper limbs. Baseline force and tracking data for four neurologically unimpaired subjects who completed bilateral and unilateral steering with the impaired arm using the device are presented.
Comparison of virtual and physical treadmill environments for training stepping
after spinal cord injury
Authors: Timoszyk W. K. , de Leon R. D. , London N. , Joynes R. , Minakata K. , Roy R. R. , Edgerton V. R. , Reinkensmeyer D. J.
Published: February 2003

We are developing robotic devices for locomotion training after spinal cord injury. In this paper, we compare two approaches to controlling and quantifying bipedal
stepping of spinal rats with robots. In the first approach, the rats stepped on a physical treadmill with robot arms attached to their lower shanks. In the second, the rats stepped on a virtual treadmill generated by the robots. The rats could step on the virtual treadmill, but stepping was more consistent, step height greater, and interlimb coordination improved on
the physical treadmill. Implications for the role of sensory input in the control of locomotion and the design robotic of step trainers are discussed.
Robotic stroke therapy assistant
Authors: Mahoney Richard M. , Van der Loos H. F. Machiel , Lum Peter S. , Burgar Chuck
Published: February 2003

The Rehabilitation Technologies Division of Applied Resources Corp. (RTD-ARC) has engaged in a Phase I effort to commercialize a robotic bi-manual therapy machine for use in stroke rehabilitation, in cooperation with the VA Rehabilitation R&D Center in Palo Alto. The robotic therapy device, called ARCMIME here in order to differentiate
it from its clinical predecessor, has the potential to improve rehabilitation outcomes significantly for individuals who have upper limb impairments due to stroke and other brain injuries.

This paper describes design considerations and clinical outcomes with regards to the Phase I system. It was found that the kinematically simpler system adequately replicated the data outcomes of the more sophisticated PUMA-based experimental test rig.
The English of shop signs in Europe
Authors: Schlick Maria
Published: February 2003

A survey with large samples trying to find out whether there is a difference in the languages chosen in store signs in a larger city and those in a provincial town, gathering a ‘baseline’ sample in Great Britain in order to see whether shop-front advertising for native speakers of English also draws on foreign languages.
The language of shop signs in Tokyo
Authors: MacGregor Laura
Published: February 2003

A report on the salient role of English in Japan's complex commercial signs. A 1989–1990 study by the National Language Research Institute found that loanwords comprise nearly 10% of Japanese language in current use, and most of these loanwords are from English. Loanword dictionary entries continue to grow: the latest katakana dictionary published by Sanseido (2000) contains 52,500 foreign word entries.
He's like ‘Do it now!’ and I'm like ‘No!’
Authors: Levey Stephen
Published: February 2003

Some innovative quotative usage among young people in London. In this article, Levey looks at its use in a south-eastern variety of English, specifically in narratives of personal experience by primary-school children in an outer London borough.
Legal lexicography: A view from the front lines
Authors: Garner Bryan A.
Published: February 2003

Notes on the compilation of a classic dictionary of law. There are essentially five big questions for the writer of a modern law dictionary – and they're pretty much the same questions faced by lexicographers of old, from Rastell to Jacob to Bouvier to Black, and these are discussed.
Why? and How? – Teaching the history of the English language in our new millennium
Authors: Buck R. A.
Published: February 2003

A discussion of the difficulties that beset teaching the history of the English language in American universities.
What do we mean by we?
Authors: Rastall Paul
Published: February 2003

Some thoughts on a complex pronoun. Some expressions seem so familiar to us
that we do not bother to reflect on the meanings they convey. We can be surprised to learn that
in some languages, like Malay, it is necessary to distinguish between we referring to
the speaker and the interlocutor (kita) and we referring to the speaker and
someone other than the interlocutor (kami). Both possibilities are covered by the English
we.
The K Factor
Authors: J. Ross Nigel
Published: February 2003

Most disciplines seem to have their “K factors”, though linguistics has so far been an exception. Now a language-related K factor has surfaced, kindled by Italian text messages and the influence of English.
English and speciesism
Authors: Dunayer Joan
Published: February 2003

On the analogy of racism and sexism, the term speciesism has been coined to highlight and protest against an exploitative relationship between humankind and the other living creatures of this planet.
The Use of VHF in Collision Avoidance at Sea
Authors: Stitt I. P. A.
Published: February 2003

The September 2002 issue of The Journal included a paper that implied that the US practice of negotiating collision avoidance manoeuvres by VHF had effectively been endorsed by the IMO. That view is challenged, by reference to the relevant provisions in the US legislation, the COLREGS and chapter IV of the SOLAS Convention. This paper also concludes that AIS will be a useful tool to provide additional information, but should not alter the way in which the COLREGS are to be applied.
Telemetric Control of Remote Vehicles using an Inverse RTK Technique
Authors: El-Mowafy Ahmed
Published: February 2003

In this study, an inverse Real Time Kinematic (RTK) GPS positioning approach is presented and discussed. GPS data from a remote receiver mounted on an unmanned vehicle is sent to the base station to determine the vehicle location at the centimetre level of accuracy in real time. Control of the vehicle's movement and manoeuvring can thus take place at the base station, which could be a few kilometres away, and the vehicle can be sent to specific locations to do certain tasks. Two GPS antennas were used in order to increase positioning reliability and estimate real time heading and pitch of the vehicle for better control. In addition, the vehicle was fitted with cameras with wireless video transmission to provide the operator with a good level of vision in different directions during operation. The main applications of such a system would be in exploration, breaching and clearance of minefields, and hazardous situations such as fire fighting of burning oil wells. The system design and techniques employed are discussed first. Issues addressed include antenna layout, data transmission, solution algorithm, and ambiguity resolution. The proposed system was mounted on a prototype vehicle and tested under different satellite visibility conditions. Results show that high positioning accuracy with reliable ambiguity resolution can be obtained with the developed approach if the number of observed satellites is 5 or more and PDOP is less than 5. Heading and pitch were determined within 0·2–0·3 degree using a 1·2 m long baseline. This performance can be improved as the length of the on-board baseline increases.
Estimation of Minimum Separation of Geostationary Satellites for Satellite-Based Augmentation System (SBAS) from Equatorial Ionospheric Scintillation Observations
Authors: Ray S. , DasGupta A. , Paul A. , Banerjee P.
Published: February 2003

In Satellite-Based Augmentation Systems (SBAS), the correction messages are transmitted to the users' receivers via geostationary communication satellites (GEOS) at GPS L1 (1575·42 MHz) frequency. Severe scintillations in the equatorial zone disrupt geostationary satellite links even at L-band. Observations of scintillations at 1·5 GHz from Calcutta (22·58°N, 88·38°E geographic, 32°N magnetic dip), located near the crest of the equatorial anomaly in the Indian zone, show that scintillations occur in patches of duration varying from a few minutes to several hours. During the solar maximum years 1998–2000, severe scintillations (Scintillation Index [ges ]15 dB) were recorded for 48 hr 55 min (1·27%) out of the total observation time of 3868 hr 9 min in the local time interval 19 to 00 hrs. In order to have a fail-safe system, it is suggested that more than one geostationary satellite be used in SBAS so that, if one link is disrupted, the other can be used for transmission of correction messages to the GPS users. The minimum longitudinal separation between two GEOS required for reliable operation of SBAS has been estimated, from the cumulative distribution of scintillation patch duration, to be 57° in the Indian longitude zone.
The Ship's Navigation Function, Ship's Navigation Processes, and Ship's Navigational Information
Authors: Kopacz Z. , Morgaś W. , Urbański J.
Published: February 2003

This paper discusses the ship's navigation function, navigation processes, and navigational information. The relationship between these concepts and their substance are analysed in depth. However, the primary aim of this paper is to consider how the various types of navigational information and their content might be brought together in a logically defined structure as a Ship's Information System.
AIS The Cornerstone of National Security?
Authors: Creech Jay A. , Ryan Joseph F.
Published: February 2003

The International Maritime Organization has mandated carriage requirements for VHF Automatic Identification System (AIS) on vessels over 300 tons by 2007 (IMO SOLAS: 1974 and IMO Resolution MSC.99(73)). The AIS will transmit a vessel's position and voyage data to other AIS-equipped vessels and shore-based authorities. It was envisioned that AIS data could enhance the safety of navigation by allowing vessels to quickly identify each other and use Digital Select Calling (DSC) to arrange maneuvers. We will discuss the history and the development of AIS, the technical issues surrounding its use by the mariner as a navigation tool and the pros and cons of the proposal by the US Coast Guard (USCG) to use AIS as a means of surveillance for Maritime Domain Awareness.
Ionosphere Propagation Error Correction for Galileo
Authors: Groves P. D. , Harding S. J.
Published: February 2003

A theoretical analysis of the effects of dual frequency ionosphere propagation correction on GNSS code tracking noise is presented. The effect on tracking noise of using different combinations of the proposed Galileo signals for ionosphere propagation correction is investigated. It is concluded that, for the open or commercial service user, the Galileo signals E2-L1-E1 near to and around GPS L1 should be used to apply ionosphere propagation corrections to the E5 signals. This produces a tracking noise standard deviation about three times larger than that on an E5 signal alone. An ionosphere correction-smoothing algorithm is presented that reduces the tracking noise on the corrected pseudo-range measurements.
GPS Integrity and Potential Impact on Aviation Safety
Authors: Ochieng Washington Y. , Sauer Knut , Walsh David , Brodin Gary , Griffin Steve , Denney Mark
Published: February 2003

This paper assesses the capability of GPS to provide the level of safety required for different aircraft flight navigation operations. It presents an analysis of the protection offered against potential catastrophic GPS failures at system and user levels. This is followed by an assessment of the different approaches to augmenting GPS for civil air navigation. Results show the inadequacy of GPS as a system for real-time safety critical use.
An Extended Dynamic Model for Kinematic Positioning
Authors: Moore Michael , Wang Jinling
Published: February 2003

The main problems faced by a dynamic model within a Kalman filter occur when the system experiences unexpected dynamic conditions, a change in data acquisition rate, or when the dynamics of the system are non-linear. To minimize the errors produced from dynamic modelling in unusual conditions, an extended dynamic model is developed in this paper, and its usefulness demonstrated through comparison of the performance of a Kalman filter's response to simulated data with a standard dynamic model and the extended dynamic model. The results show that, in use, the proposed extended dynamic model is superior to a standard dynamic model, due mainly to its ability to adapt to a wider range of dynamic conditions, which in turn ensures the optimization of the Kalman filter and the consequent generation of reliable positioning results.
Drivers' Information Requirements when Navigating in an Urban Environment
Authors: May Andrew J. , Ross Tracy , Bayer Steven H.
Published: February 2003

Navigating in unfamiliar road environments is a common and demanding cognitive activity. If this cannot be accomplished successfully, there are implications for increased driver workload, delays due to navigation errors, potentially unsafe road behaviour such as late lane changes, and inappropriate traffic management. To enable successful navigation through such environments, it is necessary to understand what the navigation task entails, and what a driver's corresponding information requirements are. This paper reports the results of a study that sought to identify what information is used by drivers when navigating within a range of urban driving environments, how this information is used, and what the implications are for the design of navigation aids.
Maps in Mind – How Animals Get Home?
Authors: Grocott D. F. H.
Published: February 2003

The ability of animals to find their way, without the benefit of mechanical or electronic aids to navigation, has fascinated humans for centuries. Relying on innate knowledge, coupled with the extraction of navigational data from the natural features of the universe, animals continually confound humans with their skills in locomotion. The magnetic compass, sun compass, strip maps, snapshots, target maps, temperature charts and star charts are known to feature in the overall animal navigation kit. Each species selects the most appropriate ‘map/chart’ and navigation kit for its environment.
A Review of Guidance Laws Applicable to Unmanned Underwater Vehicles
Authors: Naeem W. , Sutton R. , Ahmad S. M. , Burns R. S.
Published: February 2003

The main problem in bringing autonomy to any vehicle lies in the design of a suitable guidance law. For truly autonomous operation, the vehicle needs to have a reliable Navigation, Guidance and Control (NGC) system of which the guidance system is the key element that generates suitable trajectories to be followed. In this review paper, various guidance laws found in the literature and their relevance to autonomous underwater vehicles (AUVs) are discussed. Since existing guidance laws for underwater vehicles have emulated from tactical airborne missile systems, a number of approaches for the missile guidance systems are considered. Finally, potential guidance strategies for AUVs are proposed.
Adaptive Kalman Filtering for Low-cost INS/GPS
Authors: Hide Christopher , Moore Terry , Smith Martin
Published: February 2003

GPS and low-cost INS sensors are widely used for positioning and attitude determination applications. Low-cost inertial sensors exhibit large errors that can be compensated using position and velocity updates from GPS. Combining both sensors using a Kalman filter provides high-accuracy, real-time navigation. A conventional Kalman filter relies on the correct definition of the measurement and process noise matrices, which are generally defined a priori and remain fixed throughout the processing run. Adaptive Kalman filtering techniques use the residual sequences to adapt the stochastic properties of the filter on line to correspond to the temporal dependence of the errors involved. This paper examines the use of three adaptive filtering techniques. These are artificially scaling the predicted Kalman filter covariance, the Adaptive Kalman Filter and Multiple Model Adaptive Estimation. The algorithms are tested with the GPS and inertial data simulation software. A trajectory taken from a real marine trial is used to test the dynamic alignment of the inertial sensor errors. Results show that on line estimation of the stochastic properties of the inertial system can significantly improve the speed of the dynamic alignment and potentially improve the overall navigation accuracy and integrity.
A Line of Sight Counteraction Navigation Algorithm for Ship Encounter Collision Avoidance
Authors: Wilson P. A. , Harris C. J. , Hong X.
Published: February 2003

A new navigation method, called a Line of Sight Counteraction Navigation (LOSCAN) algorithm has been introduced to aid manoeuvre decision making for collision avoidance based on a two-ship encounter. The LOSCAN algorithm is derived from an extension of the basic principle of traditional missile proportional navigation, recognising that the objective of the latter is target capture rather than target avoidance. The basic concept is to derive an acceleration command so as to increase the misalignment between the ships' relative velocity and the line-of-sight. The algorithm includes a risk assessment and the generation of appropriate navigation commands to manoeuvre own ship free of collision if a risk of collision exists. Numerical examples have been used to demonstrate the effectiveness of the algorithm. The relationship between the distance at the closest point of approach with respect to early warning distance, and with the norm of the acceleration, has also been analysed. In operation, the collision avoidance decision making process is a complicated problem, with its solution subject to ship states, practical dynamic constraints, Collision Avoidance Regulations (COLREGS), encountering ship manoeuvre coordination and human decision making factors. The proposed algorithm provides a consistent manoeuvre signal to aid decision-making.
Functional Scope and Generic Model of Integrated Navigation Systems
Authors: Mathes S. , Herberg J. , Berking B. , Behnke J. , Jonas M.
Published: February 2003

The increasing degree of integration of navigation systems and of complexity of these systems place new requirements on their use, test methods and specifications. These systems (Integrated Bridge Systems, Integrated Navigation Systems, Track Control Systems) contain a large number of functionalities, which have hitherto been carried out by equipment and units clearly delimited from one another. The purpose of this study is to develop a framework for Integrated Navigation Systems that enables an equipment-independent description of the requirements in order to take account of the large range of existing systems as well as future developments. In Part A, the functions fundamental to navigation operations are identified. A hierarchical approach is used to identify the global process task, task areas, tasks, functionalities and, finally, elementary functions. In Part B, a model of the ‘integrated navigation’ process is derived from the functional analysis. With the aid of the model it is possible to identify functional dependencies and resultant error chains. A ‘three-dimensional network’ is developed that represents the information flows between the functional units. In Part C, requirements on the testing of Integrated Navigation Systems are derived from the functional model. Independent of specific technical implementations, the starting points are information flows. The requirements the functions place on their respective input information are identified. Furthermore, categorisation of the test requirements is undertaken. This paper is a shortened version of the ‘Integrated Navigation Systems scope and model’. The complete paper (183 pages) may be obtained from the authors.
1 Introduction
Authors: PEYTON JONES SIMON
Published: February 2003

Contents  i

 Preface  vii

1.1 Program Structure  3

1.2 The Haskell Kernel  4

1.3 Values and Types  4

1.4 Namespaces  5
2 Lexical Structure
Authors: PEYTON JONES SIMON
Published: February 2003

2.1 Notational Conventions  7

2.2 Lexical Program Structure  8

2.3 Comments  9

2.4 Identifiers and Operators  10

2.5 Numerical Literals  11

2.6 Character and String Literals  12

2.7 Layout  13
3 Expressions
Authors: PEYTON JONES SIMON
Published: February 2003

3.1 Errors  19

3.2 Variables, Constructors, Operators, and Literals  20

3.3 Curried Applications and Lambda Abstractions  21

3.4 Operator Applications  21

3.5 Sections  22

3.6 Conditionals  23

3.7 Lists  23

3.8 Tuples  24

3.9 Unit Expressions and Parenthesized Expessions  25

3.10 Arithmetic Sequences  25

3.11 List Comprehensions  25

3.12 Let Expressions  27

3.13 Case Expressions  27

3.14 Do Expressions  29

3.15 Datatypes with Field Labels  29

3.16 Expression Type Signatures  32

3.17 Pattern Matching  32
4 Declarations and Bindings
Authors: PEYTON JONES SIMON
Published: February 2003

4.1 Overview of Types and Classes  40

4.2 User-Defined datatypes  45

4.3 Type Classes and Overloading  49

4.4 Nested Declarations  55

4.5 Static Semantics of Function and Pattern Bindings  60

4.6 Kind Inference  66
5 Modules
Authors: PEYTON JONES SIMON
Published: February 2003

5.1 Module Structure  68

5.2 Export Lists  69

5.3 Import Declarations  71

5.4 Importing and Exporting Instance Declarations  74

5.5 Name Clashes and Closure  74

5.6 Standard Prelude  77

5.7 Separate Compilation  78

5.8 Abstract Datatypes  78
6 Predefined Types and Classes
Authors: PEYTON JONES SIMON
Published: February 2003

6.1 Standard Haskell Types  81

6.2 Strict Evaluation  84

6.3 Standard Haskell Classes  84

6.4 Numbers  91
7 Basic Input/Output
Authors: PEYTON JONES SIMON
Published: February 2003

7.1 Standard I/O Functions  97

7.2 Sequencing I/O Operations  99

7.3 Exception Handling in the I/O Monad  100
8 Standard Prelude
Authors: PEYTON JONES SIMON
Published: February 2003

8.1 Module Prelude  104

8.2 Module PreludeList  114

8.3 Module PreludeText  119

8.4 Module PreludeIO  123
9 Syntax Reference
Authors: PEYTON JONES SIMON
Published: February 2003

9.1 Notational Conventions  125

9.2 Lexical Syntax  126

9.3 Layout  128

9.4 Literate Comments  131

9.5 Context-Free Syntax  133
10 Specification of Derived Instances
Authors: PEYTON JONES SIMON
Published: February 2003

10.1 Derived Instances of Eq and Ord  140

10.2 Derived Instances of Enum  140

10.3 Derived Instances of Bounded  141

10.4 Derived Instances of Read and Show  142

10.5 An Example  143
12 Rational Numbers
Authors: PEYTON JONES SIMON
Published: February 2003

12.1 Library Ratio  150
13 Complex Numbers
Authors: PEYTON JONES SIMON
Published: February 2003

13.1 Library Complex  154
14 Numeric Functions
Authors: PEYTON JONES SIMON
Published: February 2003

14.1 Showing Functions  158

14.2 Reading Functions  159

14.3 Miscellaneous  159

14.4 Library Numeric  160
15 Indexing Operations
Authors: PEYTON JONES SIMON
Published: February 2003

15.1 Deriving Instances of Ix  170

15.2 Library Ix  171
16 Arrays
Authors: PEYTON JONES SIMON
Published: February 2003

16.1 Array Construction  174

16.2 Incremental Array Updates  175

16.3 Derived Arrays  176

16.4 Library Array  176
17 List Utilities
Authors: PEYTON JONES SIMON
Published: February 2003

17.1 Indexing Lists  181

17.2 “Set” Operations  181

17.3 List Transformations  182

17.4 unfoldr  182

17.5 Predicates  183

17.6 The “By” Operations  183

17.7 The “generic” Operations  184

17.8 Further “zip” Operations  184

17.9 Library List  184
18 Maybe Utilities
Authors: PEYTON JONES SIMON
Published: February 2003

18.1 Library Maybe  192
19 Character Utilities
Authors: PEYTON JONES SIMON
Published: February 2003

19.1 Library Char  195
20 Monad Utilities
Authors: PEYTON JONES SIMON
Published: February 2003

20.1 Naming Conventions  200

20.2 Class MonadPlus  200

20.3 Functions  201

20.4 Library Monad  202
21 Input/Output
Authors: PEYTON JONES SIMON
Published: February 2003

21.1 I/O Errors  207

21.2 Files and Handles  208

21.3 Opening and Closing Files  210

21.4 Determining the Size of a File  211

21.5 Detecting the End of Input  211

21.6 Buffering Operations  211

21.7 Repositioning Handles  213

21.8 Handle Properties  213

21.9 Text Input and Output  214

21.10 Examples  215

21.11 Library IO  216
22 Directory Functions
Authors: PEYTON JONES SIMON
Published: February 2003

Directory Functions  219
24 Dates and Times
Authors: PEYTON JONES SIMON
Published: February 2003

24.1 Library Time  227
25 Locales
Authors: PEYTON JONES SIMON
Published: February 2003

25.1 Library Locale  231
26 CPU Time
Authors: PEYTON JONES SIMON
Published: February 2003

CPU Time  233
27 Random Numbers
Authors: PEYTON JONES SIMON
Published: February 2003

27.1 The RandomGen class, and the StdGen generator  236

27.2 The Random class  239

27.3 The global random number generator  240
Bibliography
Authors: PEYTON JONES SIMON
Published: February 2003

Bibliography  241

 Index  243
A theory of mixin modules: algebraic laws and reduction semantics
Authors: ANCONA DAVIDE , ZUCCA ELENA
Published: February 2003

Mixins are modules that may contain deferred components, that is, components not defined
in the module itself; moreover, in contrast to parameterised modules (like ML functors),
they can be mutually dependent and allow their definitions to be overridden. In a preceding
paper we defined a syntax and denotational semantics of a kernel language of mixin
modules. Here, we take instead an axiomatic approach, giving a set of algebraic laws
expressing the expected properties of a small set of primitive operators on mixins.
Interpreting axioms as rewriting rules, we get a reduction semantics for the language and
prove the existence of normal forms. Moreover, we show that the model defined in the
earlier paper satisfies the given axiomatisation.
Topological and limit-space subcategories of countably-based equilogical spaces
Authors: MENNI MATÍAS , SIMPSON ALEX
Published: February 2003

There are two main approaches to obtaining ‘topological’ cartesian-closed categories. Under
one approach, one restricts to a full subcategory of topological spaces that happens to be
cartesian closed – for example, the category of sequential spaces. Under the other, one
generalises the notion of space – for example, to Scott's notion of equilogical space. In this
paper, we show that the two approaches are equivalent for a large class of objects. We first
observe that the category of countably based equilogical spaces has, in a precisely defined
sense, a largest full subcategory that can be simultaneously viewed as a full subcategory of
topological spaces. In fact, this category turns out to be equivalent to the category of all
quotient spaces of countably based topological spaces. We show that the category is
bicartesian closed with its structure inherited, on the one hand, from the category of
sequential spaces, and, on the other, from the category of equilogical spaces.
We also show that the category of countably based equilogical spaces has a larger full
subcategory that can be simultaneously viewed as a full subcategory of limit spaces. This full
subcategory is locally cartesian closed and the embeddings into limit spaces and countably
based equilogical spaces preserve this structure. We observe that it seems essential to go
beyond the realm of topological spaces to achieve this result.
Encoding left reduction in the λ-calculus with interaction nets
Authors: LIPPI SYLVAIN
Published: February 2003

This paper presents a simple implementation of the λ-calculus in the interaction net
paradigm. It is based on a two-fold translation. λ-terms are coded (for duplication) or
decoded (for execution), and reduction is achieved by switching between these two states:
decoding corresponds to head reduction and encoding to left reduction.
A proof-irrelevant model of Martin-Löf's logical framework
Authors: FRIDLENDER DANIEL
Published: February 2003

We extend the proof-irrelevant model defined in Smith (1988) to the whole of Martin-Löf's
logical framework. The main difference here is the existence of a type whose objects
themselves represent types rather than proof-objects. This means that the model must now
be able to distinguish between objects with different degree of relevance: those that denote
proofs are irrelevant whereas those that denote types are not. In fact a whole hierarchy of
relevance exists.

Another difference is the higher level of detail in the formulation of the formal theory, such
as the explicit manipulation of contexts and substitutions. This demands an equally detailed
definition of the model, including interpreting contexts and substitutions.

We are thus led to a whole reformulation of the proof-irrelevant model. We present a model
that is built up from an arbitrary model of the untyped lambda calculus. We also show how
to extend it when the logical framework itself is enlarged with inductive definitions. In doing
so, a variant of Church numerals is introduced.

As in Smith (1988), the model can only be defined in the absence of universes, and it is
useful to obtain an elementary proof of consistency and to prove the independence of
Peano's fourth axiom.
βη-complete models for System F
Authors: BERARDI STEFANO , BERLINE CHANTAL
Published: February 2003

We show that Friedman's proof of the existence of non-trivial βη-complete models
of λ→ can be extended to system F. We isolate a set of conditions that are sufficient to ensure
βη-completeness for a model of F (and α-completeness at the level of types), and we discuss
which class of models we get. In particular, the model introduced in Barbanera and
Berardi (1997), having as polymorphic maps exactly all possible Scott continuous maps, is
βη-complete, and is hence the first known complete non-syntactic model of F. In order to
have a suitable framework in which to express the conditions and develop the proof, we also
introduce the very natural notion of ‘polymax models’ of System F.
Estrogen receptor subtypes in the female reproductive tract
Authors: Saunders PTK , Critchley HOD
Published: February 2003

Estrogens are essential regulators of female fertility. Estrogen biosynthesis is dependent upon expression of the cytochrome P450 aromatase, the highest levels of expression of which are detected in the human placenta and the granulosa cells of the mature ovarian follicle. Consistent with this pattern of expression, in non-pregnant premenopausal women, the ovaries have been shown to be the primary source of estradiol. In recent years there has also been an increased interest in the role(s) played by estrogens in regulation of adipose tissue, the vasculature and bone and as paracrine regulators of tissue function in postmenopausal women. In the premenopausal years the uterus is a target for estrogen and the cyclical event of menstruation is a consequence of the sequential exposure of the endometrium to estrogen and progesterone (reviewed in references 5 and 6). Endometrial breakdown occurs as a consequence of progesterone withdrawal with the demise of the corpus luteum (CL) in the absence of pregnancy.
Recurrent miscarriage – a critical appraisal
Authors: Rai R
Published: February 2003

Only 50% of all conceptions result in a live birth (Figure 1). Human
reproduction can therefore be viewed as being remarkably inefficient. However, the diametrically
opposite opinion that it is in fact a very efficient and selective process, designed to optimize
the outcome of pregnancy, deserves to be stated.

Between 65% and 90% of clinically recognized
miscarriages are due to chromosome abnormalities, the occurrence of which is more closely related
to basal follicle-stimulating hormone (FSH) levels rather than to maternal age alone. In contrast
to women suffering a sporadic miscarriage, women who recurrently miscarry often, but not exclusively,
lose pregnancies with a normal chromosome content. Using a combination of conventional Geimsa
banding and the recently introduced technique of comparative genomic hybridization it has
been reported that 54% of pregnancy losses amongst women with recurrent miscarriage are euploid.
The challenge we face is to identify the causes of pregnancy loss amongst those couples who
recurrently lose such euploid conceptions.

Whilst many conventionally held beliefs as to the aetiology and treatment of
women with recurrent miscarriage have not withstood critical scrutiny, significant
progress has been made. This progress is the subject of this review, which will also
highlight potential areas of future research.