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Showing papers by "Northampton Community College published in 1994"


Proceedings ArticleDOI
01 Aug 1994
TL;DR: The 2-Poisson model for term frequencies is used to suggest ways of incorporating certain variables in probabilistic models for information retrieval, and substantial performance improvements are demonstrated.
Abstract: The 2-Poisson model for term frequencies is used to suggest ways of incorporating certain variables in probabilistic models for information retrieval. The variables concerned are within-document term frequency, document length, and within-query term frequency. Simple weighting functions are developed, and tested on the TREC test collection. Considerable performance improvements (over simple inverse collection frequency weighting) are demonstrated.

1,366 citations


Journal ArticleDOI
TL;DR: Three new methods of determining Littmann's factor q become available: simply reducing the axial length by a constant 1 · 82 mm; constructing a personalized schematic eye, given additional data; and ray tracing through this eye to extend calculations to peripheral retinal areas.
Abstract: Littmann's formula relating the size of a retinal feature to its measured image size on a telecentric fundus camera film is widely used. It requires only the corneal radius, ametropia, and Littmann's factor q obtained from nomograms or tables. These procedures are here computerized for practitioners' convenience. Basic optical principles are discussed, showing q to be a constant fraction of the theoretical ocular dimension k′, the distance from the eye's second principal point to the retina. If the eye's axial length is known, three new methods of determining q become available: (a) simply reducing the axial length by a constant 1 · 82 mm; (b) constructing a personalized schematic eye, given additional data; (c) ray tracing through this eye to extend calculations to peripheral retinal areas. Results of all these evaluations for 12 subjects of known ocular dimensions are presented for comparison. Method (a), the simplest, is arguably the most reliable. It shows good agreement with Littmann's supplementary procedure when the eye's axial length is known.

516 citations


Journal ArticleDOI
TL;DR: Findings raise a number of issues, including the potential impacts of continued gambling legalization on the overall rate of gambling problems in the general population and on specific at-risk groups, including women, minorities, and children.
Abstract: OBJECTIVES. A study of pathological gambling in five states provides information needed to address the public health threat that the expanding availability of legalized gambling poses to at-risk groups in the general population. METHODS. Over the course of this project, epidemiological data were collected to determine the prevalence of probable pathological gambling in the general population in each study state and demographic data were collected from pathological gamblers entering treatment programs in each state. RESULTS. Among the states surveyed, the availability of and involvement in gambling differ significantly, as does the prevalence of pathological gambling. Despite these differences, the demographics of pathological gamblers in these states are similar. Like those in the general population, pathological gamblers entering treatment in each state are similar. However, pathological gamblers entering treatment do not represent the full spectrum of individuals in the general population who experience...

457 citations


Journal ArticleDOI
TL;DR: In this article, a detailed assessment of the distributed monitoring and terrain modelling of river bed topography using a technique that combines rigorous analytical photogrammetry with rapid ground survey is presented.
Abstract: Recent research in fluvial geomorphology has emphasized the spatially distributed feedbacks amongst river channel topography, flow hydraulics and sediment transport. Although understanding of the behaviour of dynamic river channels has been increased markedly through detailed within-channel process studies, less attention has been given to the accurate monitoring and terrain modelling of river channel form using three-dimensional measurements. However, such information is useful in two distinct senses. Firstly, it is one of the necessary boundary conditions for a physically based, deterministic modelling approach in which three-dimensional topography and river discharge drive within-channel flow hydraulics and ultimately spatial patterns of erosion and deposition and therefore channel change. Secondly, research has shown that an alternative means of estimating the medium-term bedload transport rate can be based upon monitoring spatial patterns of erosion and deposition within the river channel. This paper presents a detailed assessment of the distributed monitoring and terrain modelling of river bed topography using a technique that combines rigorous analytical photogrammetry with rapid ground survey. The availability of increasingly sophisticated terrain modelling packages developed for civil engineering application allows the representation of topographic information as a landform surface. Intercomparison of landform surfaces allows visualization and quantification of spatial patterns of erosion and deposition. A detailed assessment is undertaken of the quality of the morphological information acquired. This allow some general comments to be made concerning the use of more traditional methods to monitor and represent small-scale river channel morphology.

300 citations


Journal ArticleDOI
TL;DR: The Partition Algebra Pn(Q) as mentioned in this paper is a generalisation of the Temperley-Lieb algebra for Q-state n-site Potts models, underpinning their transfer matrix formulation on arbitrary transverse lattices.
Abstract: We give the definition of the Partition Algebra Pn(Q). This is a new generalisation of the Temperley–Lieb algebra for Q-state n-site Potts models, underpinning their transfer matrix formulation on arbitrary transverse lattices. In Pn(Q) subalgebras appropriate for building the transfer matrices for all transverse lattice shapes (e.g. cubic) occur. For the Partition algebra manifests either a semi-simple generic structure or is one of a discrete set of exceptional cases. We determine the Q-generic and Q-independent structure and representation theory. In all cases (except Q = 0) simple modules are indexed by the integers j ≤ n and by the partitions λ ˫ j. Physically they may be associated, at least for sufficiently small j, to 2j 'spin' correlation functions. We exhibit a subalgebra isomorphic to the Brauer algebra.

255 citations


Journal ArticleDOI
TL;DR: The results of Study 1 suggest that around a third of the variance in fear of indigenous animals can be accounted for by two factors which represent the theoretically coherent categories of invertebrates and fear-relevant animals, and that females tend to report significantly greater levels of fear to a large majority of prevalently feared animals.
Abstract: Two studies are described which report on the prevalence and intensity of self-reported fears to common indigenous animals in an adult UK population. The results of Study 1 suggest that (i) around a third of the variance in fear of indigenous animals can be accounted for by two factors which represent the theoretically coherent categories of invertebrates (e.g. slug, worm, cockroach) and fear-relevant animals (e.g. rat, snake, bat); (ii) females tend to report significantly greater levels of fear than males to a large majority of prevalently feared animals; and (iii) there were no obviously consistent patterns of fear with age. Study 2 identifies individual disgust sensitivity levels as being an important and significant predictor of fear of animals in both the invertebrate and fear-relevant categories, and finds that females report significantly higher disgust sensitivity levels than males. Since most of the prevalently feared indigenous animals appear to be disgust-relevant, this latter finding helps to explain the generally higher fear ratings given by females.

205 citations



Journal ArticleDOI
TL;DR: The results suggest that chromatic signals are processed independently to generate perceived object colour or to construct spatially structured objects, and that these functions involve different neural substrates.
Abstract: A new method that allows controlled masking of luminance contrast has been developed to study the use of chromatic signals in human vision. The method also makes it possible to examine the different uses of chromatic signals (e.g. the generation of perceived colour, or the construction and representation of object structure and form). By using this technique, we studied the threshold detection of chromatic signals in normal trichromats. The results show that chromatic signals are virtually unaffected by ongoing, randomly varying, luminance contrast changes. These findings suggest that chromatic signals are either processed independently or can be separated completely from any confounding luminance contrast components in the stimulus. Thresholds for detection of colour changes only, and for extraction of stimulus structure from chromatic signals in normal trichromats, in subjects with single cone receptor deficiency (i.e. dichromats) and in three subjects with abnormal colour vision caused by bilateral damage to ventromedial, extra-striate visual cortex (i.e. subjects with cerebral achromatopsia) have also been measured. No significant difference in thresholds for the two conditions was observed either in normal trichromats or in dichromats. Subjects with cerebral achromatopsia, however, reveal markedly different thresholds. The results suggest that chromatic signals are processed independently to generate perceived object colour or to construct spatially structured objects, and that these functions involve different neural substrates. The results help to explain, at least in part, why cerebral achromatopsia is a heterogeneous disorder, and why there can be significant differences in the effective use of chromatic signals in subjects described as cerebral achromatopsics.

135 citations


Journal ArticleDOI
TL;DR: In this paper, a dynamic model of pension funding for a defined benefit occupational pension scheme is presented and two types of risk are introduced concerned respectively with the stability and security of funding: the contribution rate risk and the solvency risk.
Abstract: The paper presents a dynamic model of pension funding for a defined benefit occupational pension scheme. Two types of risk are introduced concerned respectively with the stability and security of funding: the ‘ contribution rate ’ risk and the ‘ solvency ’ risk. An objective function is introduced to allow the simultaneous minimization of these two risks. The paper derives optimal funding control procedures for the contribution rate subject to specified constraints.

127 citations


Journal ArticleDOI
TL;DR: The construction of a graded-difficulty spelling test for adults consisting of two alternative forms each containing 30 words (GDST, Forms A and B) argues against a single site for this type of dysgraphia and argues for further refinement of this classified spelling disorder.
Abstract: In this paper we describe the construction of a graded-difficulty spelling test for adults consisting of two alternative forms each containing 30 words (GDST, Forms A and B). The spelling test, together with background tests of verbal and non-verbal skills, was administered to 100 control patients with orthopaedic injuries. The two forms of the spelling test were highly correlated (0.92). Spelling was highly correlated with reading (0.75, 0.77) and moderately correlated with vocabulary (0.57) and naming (0.39, 0.40). There was no correlation between spelling skills and non-verbal reasoning. The test was validated in a group of 26 patients with left hemisphere and 20 patients with right hemisphere lesions. Spelling was shown to be lateralized to the left hemisphere and there appeared to be a shift in scores of the left hemisphere group towards the lower quartile, with 65% of the left hemisphere group falling within this band. The most severe spelling impairments were invariably associated with other language disorders but a number of dissociations were documented at spelling levels falling between the 5th and 25th percentile band. Two patients with left hemisphere lesions (8%) were identified as having selective dysgraphias. The lack of overlap between the anatomical sites of the two patients with specific lexical dysgraphia argues against a single site for this type of dysgraphia and argues for further refinement of this classification of spelling disorder.

101 citations


Journal ArticleDOI
TL;DR: In this article, an analytical expression for the coupled bending-torsional dynamic stiffness matrix terms of an axially loaded uniform Timoshenko beam element is derived in an exact sense by solving the governing differential equations of motion of the element.

Journal ArticleDOI
TL;DR: It is suggested that the Stroop phenomena do not have a precise relationship to the extent of psychopathology and that factors such as the ability to "fake" the test and poor concentration leading to general slowing, may explain the results.
Abstract: The specificity of the retardation effect on the Stroop Naming task with eating disorder clients was examined by comparing anorexic patients and normal weight controls with obese restrained eaters. Although the expected differences between normal weight controls and anorexics were found for color naming of food and body size words, obese restrained eaters were not differentiated from the clinical sample. It is suggested, therefore, that the Stroop phenomena do not have a precise relationship to the extent of psychopathology and that factors such as the ability to “fake” the test and poor concentration leading to general slowing, may explain the results. © 1994 by John Wiley & Sons, Inc.

Journal ArticleDOI
TL;DR: Psychophysical experiments carried out on a subject clinically blind in half of his visual field caused by striate cortex damage reveal the existence of two distinct channels mediating residual vision, one responds to spatial structure and the other to light flux changes.
Abstract: Residual vision in subjects with damage of the primary visual cortex (striate cortex) has been demonstrated in many previous studies and is taken to reflect the properties of known subcortical and extrastriate visual pathways. In this report we describe psychophysical experiments carried out on a subject clinically blind in half of his visual field (i.e. homonymous hemianopia) caused by striate cortex damage. They reveal the existence of two distinct channels mediating such vision. One channel responds to spatial structure and the other to light flux changes. The spatially tuned channel has a peak response at about 1.2 cycles per degree and shows rapid loss of sensitivity at both high and low spatial frequencies. This channel does not respond to diffuse illumination. The light flux channel, however, responds only to sudden increments in light flux levels on the retina and shows extensive spatial summation. Both channels require transient inputs, with a peak sensitivity at about 10 cycles per second and show virtually complete attenuation at temporal frequencies below 2 cycles per second. The spatiotemporal characteristics of these two channels account for much of the reported limits of visual performance attributed to subcortical or extrastriate pathways in some patients, and especially for their relatively good sensitivity for the detection of abrupt, transient stimuli or fast-moving targets. A new method is also applied to the measurement of the amount of light scatter in the eye. The measurements show that light scatter into the sighted hemifield could not account for the results obtained with the stimuli used to characterized the residual vision of this subject.

Journal ArticleDOI
TL;DR: In New Zealand pathological gambling appears to have a lifetime prevalence approximately half that of drug abuse/dependence, suggesting that prevalence has increased in recent years and providing a baseline for further study.
Abstract: BACKGROUND Legalized gambling has proliferated recently in many countries and is a public health issue because of the association between gambling participation and the prevalence of pathological gambling. Relatively little is known about the epidemiology of this disorder or the characteristics of pathological gamblers living in the community. This paper summarizes the major findings of a national prevalence survey of pathological gambling conducted in New Zealand; the first national survey to have been conducted to date, and compares them with the results of studies undertaken in the US and Canada. METHODS A national adult sample of 4053 people was interviewed by telephone to determine involvement in gambling activities. The interview included the South Oaks Gambling Screen (SOGS) for pathological gambling. RESULTS Of the sample, 2.7% (+/- 0.5%) scored as probable pathological gamblers and a further 4.2% (+/- 0.6%) scored as problem gamblers. These prevalence rates are higher than those reported in previous studies using the SOGS. Ethnicity, age, gender, employment status, having a parent who had gambling problems and regular participation in continuous forms of gambling were major risk factors. CONCLUSIONS In New Zealand pathological gambling appears to have a lifetime prevalence approximately half that of drug abuse/dependence. The findings suggest that prevalence has increased in recent years and provide a baseline for further study. The risk factors identified give a focus for future research into aetiology, prevention and treatment.

Journal ArticleDOI
TL;DR: The paper provides an analytical review of the development of Measurement and Instrumentation Science and provides references to key literature.

Journal ArticleDOI
TL;DR: In this paper, the authors examine the problem of underachievement in organization change programs, where the original ambitions of the authors of change fail to be realized at the level of implementation.
Abstract: SUMMARY This paper examines the relatively unexplored area of underachievement in organization change programmes, where the original ambitions of the authors of change fail to be realized at the level of implementation. A case in point is the British Civil Service which after several years of government endeavour has not seen the large-scale, ‘second order’ change that had been expected. The paper offers a cultural perspective on this issue. Using the findings from an in-depth, ethnographic study of one of the newly formed agencies within the civil service, it argues that attempts at change can be frustrated by a ‘cultural infrastructure’ at the local level which acts to neutralize any attempt to change from above - in relative power terms a case of David defeating Goliath. This structure is a social defence against the anxieties and ambiguities brought about by the threat of impending change, and is manifested not as resistance, or even avoidance, but disregard and unstudied indifference. These local cultural orientations are the cause of ‘schematic myopia’ (Harris, 1989) or collective blindness, which prevent those affected from recognizing the significance of a major change initiative. An examination of these cultural processes reveals the inherent weaknesses and limitations of one of the most ubiquitous of change models to be found in organizations today: the top-down, ‘invasionary’ approach to change.

Proceedings ArticleDOI
24 Apr 1994
TL;DR: The study investigates task based information analysis, persistence of information, selective attention and concurrency in presentation, and guidelines for media selection and presentation scripting in Multimedia presentation interfaces.
Abstract: Current Multimedia interfaces are created primarily by intuition. Development of a method for analysis and design of Multimedia presentation interfaces is described. The study investigates task based information analysis, persistence of information, selective attention and concurrency in presentation. The method gives an agenda of issues, diagrams and techniques for specification, and guidelines for media selection and presentation scripting. Use of the method is illustrated with an example from a shipboard emergency management system.

Journal ArticleDOI
TL;DR: A review of the literature indicates that biomechanical orthoses will reduce rearfoot movement, but the effect on knee function is negligible and the clinical significance of excessive rear foot movement is yet to be proven.
Abstract: While it is documented that many overuse injuries of the lower limb can be relieved with the use of biomechanical foot orthoses, what remains unclear is how an orthosis can produce this effect. A review of the literature indicates that biomechanical orthoses will reduce rearfoot movement, but the effect on knee function is negligible and the clinical significance of excessive rearfoot movement is yet to be proven. While many athletes may potentially benefit from the use of biomechanical orthoses, further research is necessary to justify and, if indicated, promote the use of biomechanical foot arthoses by athletes suffering from overuse injuries.

Journal ArticleDOI
TL;DR: This paper gives an extension of the notion of compactness in an L -fuzzy topological space to arbitrary L - fuzzy subsets and study its properties.

Journal ArticleDOI
TL;DR: Results of computer modeling show that a higher degree of birefringence can be obtained with the use of a larger cladding and larger stress-applying zones in the fiber.
Abstract: Birefringence induced by thermal stress in bow-tie optical fibers is studied in detail by the use of the finite-element method. Results of computer modeling show that a higher degree of birefringence can be obtained with the use of a larger cladding and larger stress-applying zones in the fiber.

Journal ArticleDOI
TL;DR: Rainbird as mentioned in this paper found that although the integration of the training function into other policy areas, and of employees through involvement in training programmes, had not occurred to a great extent, nevertheless some of the undertakings had shown themselves capable of developing a more strategic approach to training.
Abstract: Helen Rainbird, who is Reader in Social Sciences at Nene College, Northampton, draws on detailed case study evidence from 21 undertakings in the public and private sector to consider the organisation of the training function. She finds that, although the integration of the training function into other policy areas, and of employees through involvement in training programmes, had not occurred to a great extent, nevertheless some of the undertakings had shown themselves capable of developing a more strategic approach to training. This was notably the case in two high technology companies, operating in highly competitive international markets, and in the public sector, where there was a stronger tradition and culture of training.

Patent
10 Jan 1994
TL;DR: In this paper, an open construction wiper is used to remove hydrogen bubbles and/or outwardly extend dendritic coating material with minimum contact with and force upon the coating surface, allowing free access to the coated surface at all times of fresh undepleted coating electrolyte.
Abstract: Thick layers of hard dense chromium coatings are formed on metal substrates by an electrolytic brush plating operation in which a lead-tin anode is closely positioned to a cathodic workpiece in full anode wrap relationship and the surface of the cathodic workpiece is wiped by an open construction wiper to remove hydrogen bubbles and/or outwardly extending dendritic coating material with minimum contact with and force upon the coating surface. The open wiper construction allows free access to the coated surface at all times of fresh undepleted coating electrolyte and allows hydrogen bubbles and dendritic material to be discharged unimpeded from the wiper structure.

Journal ArticleDOI
TL;DR: A high index of suspicion is needed to diagnose orthostatic hypotension in the elderly and the condition is often overlooked and the paper provides useful diagnostic clues for clinicians.
Abstract: Fifty cases of orthostatic hypotension in the elderly are analysed. Three main modes of presentation were identified: (1) falls or mobility problems; (2) mental confusion or dementia; or (3) predominantly cardiac symptoms. Selected case histories are given to illustrate diagnostic difficulties. Medication was responsible for orthostatic hypotension in 66% of patients and striking examples of polypharmacy were encountered. However, 34% of cases were not iatrogenic. Only 14% of patients had overtly postural symptoms. A high index of suspicion is needed to diagnose orthostatic hypotension in the elderly and the condition is often overlooked. The paper provides useful diagnostic clues for clinicians.

Journal ArticleDOI
TL;DR: In this article, the process of reflection is analysed into three components: an ego-driven purpose, a restructuring capability, and a transforming perspective, and different types of reflection are argued to be instances of cognitive restructuring determined by purpose and by context.
Abstract: The process of reflection is analysed into three components ‐an ego‐driven purpose, a restructuring capability, and a transforming perspective. Different types of reflection are argued to be instances of cognitive restructuring determined by purpose and by context. Procedures for resolving contradictions in the literature concerning ways in which ‘reflective teaching’ can be fostered are also suggested. It is argued that adopting any single model of ‘reflective practice’ can be unnecessarily restrictive given the ubiquity of the reflective process. Finally, the danger of claiming too much for a ‘reflective practitioner’ model is set beside clear benefits gained from promoting it.

Journal ArticleDOI
TL;DR: In this paper, the authors analyze what is meant by intelligent and knowledge based instrumentation, presenting, and as far as possible clarifying, the underlying concepts, and discuss the capabilities of intelligent instrumentation.

Patent
30 Sep 1994
TL;DR: In this paper, a continuous strip is electrolytically coated in an electrolytic coating bath using a thin flexible or resilient dielectric wiper blade to wipe bubbles of hydrogen from the surface, sever dendritic material, and to remove a surface layer of partially depleted electrolytic solution, replacing with fresh solution and to stabilize strip portions extending between support rolls.
Abstract: A continuous strip is electrolytically coated in an electrolytic coating bath using a thin flexible or resilient dielectric wiping blade to wipe bubbles of hydrogen from the surface, sever dendritic material, if such is present as the coating thickens, and to remove a surface layer of partially depleted electrolytic solution, replacing with fresh solution and to stabilize strip portions extending between support rolls. The resilient dielectric wiper blade is preferably used with perforated anodes which allow fresh electrolytic solution to flow into the space between the anodes and the strip surface after being expelled by passage of the strip past the wiping blade. The orifices in the anode may be differentially sized to eliminate cavitation behind the wiping blades. The wiping blades may be chevron shaped to increase the wiping effect and pumps may be used to increase the flow of electrolytic solution into and out of the space between the anodes and the strip. Chevron shaped wiping blades may be used to increase the wiping effectiveness and continuous movable wiping blades may be used to provides additional wiping surface as the original wiping surface wears down. The wiping blades may also be angularly oriented with respect to the strip to increase the wiping effectiveness.

Journal ArticleDOI
TL;DR: In this paper, a mathematical model is described which facilitates the comparison of different pension funding methods, and a discussion of methods of funding which are optimal in the sense of the period for spreading surpluses and deficiencies which should be chosen in order to reduce the variability of both contributions and fund levels.
Abstract: A mathematical model is described which facilitates the comparison of different pension funding methods. Real investment rates of return on the pension fund are assumed to be represented by an autoregressive model for the corresponding force of interest. Expressions for the moments of the contribution rate and fund level are then derived. This leads to a discussion of methods of funding which are optimal in the sense of the period for spreading surpluses and deficiencies which should be chosen in order to reduce the variability of both contributions and fund levels.

Journal ArticleDOI
TL;DR: The authors found that the clearest discriminator between correct and incorrect classification of children was parental experience, with parents clearly doing significantly better than non-parents, indicating that life experience may be an important competency in this area.
Abstract: Three groups of participants, 20 social workers in the final year of their training, 20 trainee teachers, and 20 student controls, were assessed on their effectiveness in deciding if children were lying or telling the truth. Although differences did occur across groups, no group displayed overall superiority. The clearest discriminator between correct and incorrect classification of children was parental experience, with parents clearly doing significantly better than non-parents. The indication is that life experience may be an important competency in this area.

Journal ArticleDOI
TL;DR: In this article, a case study of nine retailers who adopted EDI during 1987-92 is used to discuss the reasons why EDI was delayed until 1986-93 even though it was technically possible in the early 1980s.
Abstract: Considers EDI for retailers in the context of innovation theory. A case study of nine retailers who adopted EDI during 1987‐92 is used to discuss the reasons why EDI was delayed until 1986‐93 even though it was technically possible in the early 1980s. Argues that an innovation will not join the portfolio of “possibles” until three issues are resolved. These are (1) innovation “poles” to disseminate EDI know‐how, (2) cost and performance improvements to the technology, and (3) management learning, based (in this case) on learning developed from handling EPoS. Also considers the decision‐making process underlying EDI.

Journal ArticleDOI
TL;DR: In this paper, the synthesis of nitrophenols from phenol by reaction with nitrogen dioxide in solution involves two stages, the first being the abstraction of a hydrogen atom from the hydroxyl group by NO2 and the second the reaction of the phenoxy radical formed with NO2.