Showing papers by "City University London published in 1989"
TL;DR: The authors formalize the notion of methodological diversity by considering the sequence of decision outcomes that constitute a methodology and show that diversity of decision implies likely diversity of behavior for the different versions developed under such forced diversity.
Abstract: Work by D.E. Eckhardt and L.D. Lee (1985), shows that independently developed program versions fail dependently. The authors show that there is a precise duality between input choice and program choice in this model and consider a generalization in which different versions can be developed using diverse methodologies. The use of diverse methodologies is shown to decrease the probability of the simultaneous failure of several versions. Indeed, it is theoretically possible to obtain versions which exhibit better than independent failure behavior. The authors formalize the notion of methodological diversity by considering the sequence of decision outcomes that constitute a methodology. They show that diversity of decision implies likely diversity of behavior for the different versions developed under such forced diversity. For certain one-out-of-n systems the authors obtain an optimal method for allocating diversity between versions. For two-out-of-three systems there seem to be no simple optimality results which do not depend on constraints which cannot be verified in practice. >
261 citations
TL;DR: The results suggest that the factors which influence the acquisition and modulation of dental anxieties are consistent with the associative and representational processes portrayed in contemporary models of human conditioning.
224 citations
TL;DR: In this article, the authors consider the reasons for the current disillusionment of many concerned with "equal opportunities" policies in employment and review the potential of an EO orientation for progressive change within organisations and draw on her current research on responses to EO.
Abstract: Here the author considers the reasons for the current disillusionment of many concerned with ‘equal opportunities’ policies in employment and reviews the potential of an EO orientation for progressive change within organisations and draws on her current research on responses to EO, citing a company in the retail sector.
185 citations
TL;DR: This paper describes a method of segmenting curves in images into a combination of circular arcs and straight lines using a recursive algorithm that first analyses lists of connected edge points and finds a polygonal description, and then analyses this description fitting arcs to groups of connected lines.
174 citations
TL;DR: In this paper, an econometric model of the world market for dry cargo freight and shipping is presented, with a focus on the distribution of freight and ship traffic in the world.
Abstract: (1989). An econometric model of the world market for dry cargo freight and shipping. Applied Economics: Vol. 21, No. 3, pp. 339-356.
112 citations
TL;DR: A number of ways in which UCS revaluation can be effected in human subjects are discussed, and their implications for conditioning models of acquired fears are discussed.
103 citations
TL;DR: Based on their spectral transmission, the lenses of 50 teleost species can be classified into three categories: "type 1" colourless lenses, which also appear colourless but have 50% cut-off points around 362-405 nm, and "type 3" lenses which are visibly yellow (50% transmission 425-450 nm).
99 citations
TL;DR: A case is made for regarding timing in music as both a medium to convey structure and an object in its own right, suggesting that it may be perceptually organized in two different ways — as the consequence of a structural interpretation and as a directly registered quantity.
Abstract: This paper is concerned with the perception of small-scale timing changes in musical sequences. The control and expressive function of these have been studied quite extensively from a production perspective, but not much is known about listeners' ability to detect them. A pilot study and two experiments are reported which investigate the detectability of different amounts of timing change in different sequential positions, different pitch contexts, and against the background of both metronomic and expressive comparisons. The results show that listeners are able to perceive as little as 20 ms lengthening in the context of notes lasting between 100 and 400 ms, and that this threshold appears not to be a function of base duration in this range. Sequential position and pitch structure influence the detectability of timing changes to a limited extent, for which some possible explanations are offered. A case is made for regarding timing in music as both a medium to convey structure and an object in its own right, suggesting that it may be perceptually organized in two different ways — as the consequence of a structural interpretation and as a directly registered quantity.
92 citations
TL;DR: For men, particularly amongst those who had experienced a broken marriage, it was the most ambitious, the highly educated and those in professional occupations who were relatively more likely to be childless.
Abstract: Who are the men and women who are childless in their mid-30s? Life history data for a British cohort born in 1946 show that age at marriage and marital breakdown were clearly associated with childlessness. Women who were only children were more likely to be childless than those with siblings. Further, early menarcheal age, being highly qualified and having a high status occupation were indirectly related to childlessness. For men, particularly amongst those who had experienced a broken marriage, it was the most ambitious, the highly educated and those in professional occupations who were relatively more likely to be childless.
83 citations
TL;DR: It is suggested that a contemporary conditioning model of acquired fears is not bound by the need to discover contiguous stimulus-trauma experiences in the histories of clinical phobias since, in humans at least, processes of stimulus association and UCS revaluation appear to be relatively independent.
73 citations
Journal Article•
TL;DR: The human extraocular muscle spindles have lost, either by aging or phylogenetically, the privilege of contractile chambers isolated by a fluid periaxial space from extrafusal fibre activity and sensory terminals are subject to the direct mechanical influences of anomalous intrafusal fibres.
Abstract: Twenty seven muscle spindles from six extraocular muscles removed following ocular enucleation from patients aged 58, 76 and 74 years were examined throughout all or most of their length by means of light and electron microscopy using serial transverse sections. Five others were prepared in longitudinal section. Twelve spindles of the superior rectus muscle from three sheep orbits were studied in a similar manner to provide a comparison. The human spindles contained a total of 90 (42%) nuclear chain and 5 (2%) nuclear bag fibres with the usual complement of sensory endings, and 120 (56%) fibres were anomalous with continuous, unattenuated myofibrils throughout their length, a constant width and peripherally placed nuclei. Eight anomalous fibres received sensory terminals similar in form to those of chain and bag fibres. Most (26) spindles contained at least one chain and one anomalous fibre. The periaxial space was limited or absent and the inner capsule was often segmented and in contact with the outer capsule. Abrupt termination of some chain fibres including several with one pole missing, together with evidence of fibre fragmentation and other structural anomalies, were indicative of degeneration. Eight further encapsulated fibre groups were identified as false spindles containing only anomalous fibres; associated nerves failed to terminate in the encapsulations. Sheep spindle content was of regular form, all spindles containing several chain and at least one bag fibre enclosed by an inner capsule and surrounded by a substantial periaxial space equatorially. The human extraocular muscle spindles have lost, either by aging or phylogenetically, the privilege of contractile chambers isolated by a fluid periaxial space from extrafusal fibre activity and sensory terminals are subject to the direct mechanical influences of anomalous intrafusal fibres. These, and the other departures from normal structure described, must jeopardize monitoring of muscle activity in the manner normally attributed to spindles and their capacity to provide useful proprioceptive information is questionable.
TL;DR: In this paper, a new treatment is proposed that formally retains classic wall functions and scaling based on the near-wall turbulent kinetic energy, but allows the nondimensional thickness of the viscous sublayer to vary as a function of the local turbulence intensity.
Abstract: Different wall treatments, proposed in conjunction with the k-e turbulence model to predict heat or mass transfer rates, are critically reviewed. Published comparisons with experimental data for recirculating flows show that, in most cases, Nusselt or Sherwood numbers are not well predicted in the reattachment and redevelopment regions by methods based on conventional wall functions. The use of low-Reynolds-number models leads to even more unreliable results. A new treatment is proposed that formally retains classic wall functions and scaling based on the near-wall turbulent kinetic energy, but allows the nondimensional thickness of the viscous sublayer to vary as a function of the local turbulence intensity. The rationale for this approach, and its physical meaning, are discussed in the context of recent near-wall turbulence data. Using the k-e computer code FLOW3D, results are compared with those from a standard treatment, and with experimental data, for different geometries including single an...
TL;DR: A four-stage model of the interpretation of metrics which comprises the identification of abnormal metric values, possible causes of exceptions, additional information required to distinguish between causes, and possible corrective actions is presented.
Abstract: This paper provides a preliminary overview of a procedure for monitoring software development with respect to quality. The monitoring process is based on the extraction, analysis and interpretation of metrics relating to software products and processes. In particular, we are concerned with the problem of interpreting software metrics data in terms that are meaningful to project and quality managers. We present a four-stage model of the interpretation of metrics which comprises the identification of abnormal metric values (i.e. exceptions), possible causes of exceptions, additional information required to distinguish between causes, and possible corrective actions. We envisage that the model could be implemented as an advice system for managers. We discuss the general principles of project monitoring throughout the development life-cycle, and identify metrics that may be collected throughout, from requirements specification to integration testing. We suggest some general principles for assessing the cause of abnormal metric values, for distinguishing between causes, and for responding to unfavourable project circumstances.
TL;DR: There seems to be a statistically significant association between work in the leather industry and subsequent development of motoneuron disease, and occupational exposure to solvents may damage motoneurons.
TL;DR: Spect spectral transmission curves (250-700 nm) for the lenses and corneas of two teleost species known to be u.v. sensitive; brown trout aged 0-3 yr, and goldfish aged0-4 yr are reported.
TL;DR: Muller as mentioned in this paper described his attempts to correct his own -14.00 diopters of myopia with "cornea-lenses" which were essentially glass scleral lenses.
TL;DR: A wide range of results is obtained in each diagnostic group and the error score cannot be used to distinguish between dichromats and anomalous trichromats.
Journal Article•
TL;DR: Examination of the reasons for breakage and a review of the literature indicated that physical stress on the condom is likely to be a major factor in these incidents.
Abstract: Following a postal questionnaire survey of 262 homosexual men carried out to investigate condom use during sexual activity, a sample of 97 men who used condoms during anogenital sex was identified. Thirty-one percent of those who had used a condom during anal intercourse reported at least one incident of condom breakage. When looked at in terms of frequency of individual condom use, it was found that 1 in 27 condoms break during this activity. Examination of the reasons for breakage and a review of the literature indicated that physical stress on the condom is likely to be a major factor in these incidents.
01 Sep 1989
TL;DR: Many of the observations and recommendations embodied in Müller's thesis, such as the importance of a good fit, adequate tear flow and rounded edges, are still relevant to contact lens practice today.
Abstract: In celebration of the centenary of August Muller's pioneering work on contact lenses, we present, for the first time, a full translation into English of Part III of his inaugural dissertation. Muller describes his attempts to correct his own -14.00 diopters of myopia with "cornea-lenses," which were essentially glass scleral lenses. His inability to tolerate lens wear for more than half an hour was probably due to a) limbal pressure as a result of the primary optic diameter being too small, and b) the use of water to occupy the space between the lens and cornea, which would have induced severe corneal edema. Many of the observations and recommendations embodied in Muller's thesis, such as the importance of a good fit, adequate tear flow and rounded edges, are still relevant to contact lens practice today.
TL;DR: In this article, an information processing model of reading was used to identify the locus of reading and spelling disorders, and a patient was found to exhibit the symptoms of surface dyslexia with surface dysgraphia, with a reliance on phonological decoding of the printed word to achieve comprehension.
Abstract: An information processing model of reading was used to identify the locus of a reading and spelling disorder. The patient was found to exhibit the symptoms of surface dyslexia with surface dysgraphia, with a reliance on phonological decoding of the printed word to achieve comprehension. As a result, many errors were made in comprehending homophones. A remediation progrmmae presented on a microcomputer was implemented to retrain the recognition and comprehension of a set of written homophones. The patient improved in her ability to both recognise and comprehend homophones, but no generalization of the improvement to spelling of homophones took place.
TL;DR: In this article, the classification of subspaces of the state space of generalized linear systems is reduced to an equivalent problem of classifying the subspaceV of the domain of an ordered pair (F, G), F, Geℝm×n.
Abstract: Generalized linear systems are classified according to their algebraic structure and their regularizability and normalizability properties under generalized state feedback are investigated. New feedback invariants are introduced in terms of the input-space restriction pencil and the Plucker matrix of the system. It is shown that the classification of subspaces of the state space of generalized linear systems is reduced to an equivalent problem of classifying the subspacesV of the domain of an ordered pair (F, G), F, Geℝm×n. The set of strict equivalence invariants of the restriction pencil (F, G)/V provides a complete, basis-free algebraic characterization and leads to the definition of notions of geometric invariance. The key geometric notions that emerge are those of (F, G)-, (G, F)-, complete-(F, G)-, partitioned(F, G)-, cyclic-, and semicyclic-invariant subspaces. A complete set of geometric algorithms leading to the computation of the above families is also given. The above families of invariant subspaces are characterized in terms of the invariants of (F, G)/V, and this provides the links with their dynamic characterization. These results provide an “open-loop” or “feedback-free” unifying treatment of spaces of generalized systems, which for the case of proper systems is reduced to the standard geometric theory results.
TL;DR: A complete English translation is presented of the communication given in 1888 by Professor Photinos Panas in which he reported the innovative use by his junior colleague, Dr. Eugène Kalt, of a contact shell in a case of keratoconus.
Abstract: A complete English translation is presented of the communication given in 1888 by Professor Photinos Panas in which he reported the innovative use by his junior colleague, Dr. Eugene Kalt, of a contact shell in a case of keratoconus. The patient showed a dramatic visual improvement but toler
TL;DR: In this paper, the authors made an estimate of the amounts of CO and total hydrocarbons released into the atmosphere as a result of man's activities and influence and found that although man-made, and man-controlled natural, emissions of both CO and HC are still increasing, the rate of increase is falling and possible reasons for this are suggested.
TL;DR: In this paper, a two-stage steady-state system identification technique is proposed and employed in the presented approach to estimate the expectation of the real process derivative, which has reduced significantly the required controller set point changes and is much less sensitive when subjected to noise.
Abstract: An underlying relationship between a dynamic stochastic control system and its steady-state counterpart is thoroughly investigated. A novel approach which uses both dynamic and steady-state information for solving the stochastic steady-state optimizing control problem is presented. A two-stage steady-state system identification technique is proposed and employed in the presented approach to estimate the expectation of the real process derivative. Compared with integrated system optimization and parameter estimation (ISOPE) methods, this new approach has reduced significantly the required controller set point changes and is much less sensitive when subjected to noise. Optimality of the algorithm is examined and sufficient conditions for global convergence are provided. Consistency and asymptotic behaviour of the two-stage identification method are also investigated. Computer simulations are provided and comparisons are made between the ISOPE method and the presented approach. Simulation results show that t...
TL;DR: It is concluded that light adaptive cone contraction is triggered by light absorption in rods, which in the dark adapted state are located next to the external limiting membrane and are therefore in an optimal position to capture the incident light during early dawn.
TL;DR: In this paper, the effect of a radial d.c. electric field on nucleate boiling heat transfer was investigated experimentally using a single-tube shell/tube heat exchanger, where a dielectric liquid (Freon R. 114) was used in the shell and the tube was heated by circulating water through it.
Abstract: The effect of a radial d.c. electric field on nucleate boiling heat transfer was investigated experimentally using a single-tube shell/tube heat exchanger. A dielectric liquid (Freon R. 114) was used in the shell and the tube was heated by circulating water through it. It was found that the application of a sufficiently intense electric field to the boiling heat transfer surface resulted both in the elimination of boiling hysteresis and the enhancement of heat transfer for the range of superheat studied. An application of approximately 20 kV was more than sufficient to eliminate the hysteresis. It was also observed that there appeared to be a transition between two situations. At lower superheat there is an appreciable improvement in the heat transfer coefficient due to both initial (0 to 10 kV) and incremental (10 to 20 kV) voltage increases. At higher superheat, however, the greater improvement (about four times) is obtained with the initial voltage application
TL;DR: In this paper, the authors derived the effective thermal conductivity from the rate of entropy production per unit volume, where the Fourier components of thermal conductivities and the temperature field are related.
Abstract: The effective thermal conductivity is calculated from the rate of entropy production per unit volume. Thermal conductivity and the temperature field are expressed in terms of Fourier components and these are related. The rate of entropy production is then obtained in terms of the volume-averaged thermal conductivity and the Fourier components of thermal conductivity. A simple expression for the effective thermal conductivity is found. In the case of striations it leads to well-known results. The formalism is applied to solids with inhomogeneously distributed solutes. It is shown that the thermal conductivity is less than the volume-averaged thermal conductivity and that homogenization by diffusion increases the thermal conductivity. Similar results would apply to the electrical conductivity of inhomogeneous alloys.
TL;DR: The principles and prototyping of a computer-based system, implemented in Prolog, can be used to provide advice concerning insulin therapy by means of making qualitative predictions of patient outcome of blood glucose profile resulting from alternative insulin regimens.