Human performance modelling as an aid to manufacturing system design

Once the factory worker was considered to be a necessary evil, soon to be replaced by robotics and automation. Today, many manufacturers appreciate that people in direct productive roles can provide important flexibility and responsiveness, and so significantly contribute to business success. The challenge is no longer to design people out of the factory, but to design factory environment that help to get the best performance from people. This paper describes research that has set out to help to achieve this by expanding the capabilities of simulation modeling tools currently used by practitioners.

Use of Google as a tool to aid diagnosis by optometry students

Background: Previous work has shown that medical problems can be diagnosed by practitioners using Google. The aim of this study was to determine whether optometry students would benefit from using Google when diagnosing eye diseases. Methods: Participants were given symptoms and signs and instructed to list three key words and use them to search Aston University e-Library and Google UK. Results: Aston University e-Library only search resulted in correct diagnosis in 16 of 60 simulated cases. Aston e-Library plus Google search resulted in correct diagnosis in 31 of 60 simulated cases. Conclusion: Google is a useful aid to help optometry students improve their success rate when diagnosing eye conditions.

Bottom-up risk regulation? How nanotechnology risk knowledge gaps challenge federal and state environmental agencies

Nanotechnologies have been called the "Next Industrial Revolution." At the same time, scientists are raising concerns about the potential health and environmental risks related to the nano-sized materials used in nanotechnologies. Analyses suggest that current U.S. federal regulatory structures are not likely to adequately address these risks in a proactive manner. Given these trends, the premise of this paper is that state and local-level agencies will likely deal with many "end-of-pipe" issues as nanomaterials enter environmental media without prior toxicity testing, federal standards, or emissions controls. In this paper we (1) briefly describe potential environmental risks and benefits related to emerging nanotechnologies; (2) outline the capacities of the Toxic Substances Control Act, the Clean Air Act, the Clean Water Act, and the Resources Conservation and Recovery Act to address potential nanotechnology risks, and how risk data gaps challenge these regulations; (3) outline some of the key data gaps that challenge state-level regulatory capacities to address nanotechnologies' potential risks, using Wisconsin as a case study; and (4) discuss advantages and disadvantages of state versus federal approaches to nanotechnology risk regulation. In summary, we suggest some ways government agencies can be better prepared to address nanotechnology risk knowledge gaps and risk management.

Environmental quality in residential areas : a social survey approach to improvement priorities

The research is concerned with the measurement of residents' evaluations of the environmental quality of residential areas. The research reflects the increased attention being given to residents' values in planning decisions affecting the residential environment. The work was undertaken in co-operation with a local authority which was in the process of revising its housing strategy, and in particular the priorities for improvement action. The study critically examines the existing evidence on environmental values and their relationship to the environment and points to a number of methodological and conceptual deficiencies. The research strategy developed on the basis of the research review was constrained by the need to keep any survey methods simple so that they could easily be repeated, when necessary, by the sponsoring authority. A basic perception model was assumed, and a social survey carried out to measure residents' responses to different environmental conditions. The data was only assumed to have ordinal properties, necessitating the extensive use of non-parametric statistics. Residents' expressions of satisfaction with the component elements of the environment (ranging from convenience to upkeep and privacy) were successfully related to 'objective' measures of the environment. However the survey evidence did not justify the use of the 'objective' variables as environmental standards. A method of using the social survey data directly as an aid to decision-making is discussed. Alternative models of the derivation of overall satisfaction with the environment are tested, and the values implied by the additive model compared with residents' preferences as measured directly in the survey. Residents' overall satisfactions with the residential environment were most closely related to their satisfactions with the "Appearance" and the "Reputation" of their areas. By contrast the most important directly measured preference was "Friendliness of area". The differences point to the need to define concepts used in social research clearly in operational terms, and to take care in the use of values 'measured' by different methods.

Where are UK manufacturers along the journey to Lean?

Lean manufacturing is now widely accepted amongst UK based manufacturers as a valuable aid to achieving competitiveness. The associated principles, tools and techniques have been well documented since the 1980s and there are many competent practitioners, consultants and academics promoting Lean manufacturing. Therefore, it is useful to ask how well UK manufacturers are progressing along the Lean journey? This paper therefore provides an insight into this question by presenting the results, based on indepth case studies of five representative companies, that reflect progress being made within the UK manufacturing sector.

Are democratising countries ‘rewarded’ with higher levels of foreign aid?

The paper examines how flows of foreign aid have reacted to events of democratisation in developing countries. Using a panel dataset of 136 aid-receiving countries between 1980 and 2009, aid allocation regressions reveal that Western donors in general have tended to react to visible, major democratic transitions by increasing aid to the partner country, but no significant increases can be identified in the case of countries introducing smaller democratic reforms. The increases in aid flows are not sustained over time, implying that donors do not provide long-term support to nascent democracies. Also, democratisations in Sub-Saharan Africa do not seem to have been rewarded with higher levels of aid.

Problematising the construction of journal quality:an engagement with the mainstream

Journal ranking studies have generally adopted citation techniques or academic perceptions as the basis for assessing journal quality. They have traditionally been a source of information about potential research outlets, new journals, and an aid to developing a consensus about the relative merit of publications for promotion decisions. The aim of our research is to address specific shortcomings in the conventional literature and construct an alternative view of how we might more appropriately assess journal ‘quality’. We attempt to engage with the conventional literature by applying an approach that does not privilege either citation techniques or academic perceptions. We have adopted from Zeff (1996) an objective measure of academic journal library holdings, which Zeff describes as a ‘market test’. Our construct provides evidence of an important difference in journal holdings for the Australasian region that could significantly influence further research on journal quality. The method itself is entirely mundane but may be considered to reflect a complex of historic and more contemporary variables which impact on academic and administrative decisions, influencing the makeup of academic library holdings and providing a proxy for journal ‘quality’.

Expert systems for fault tree synthesis

Hazard and operability (HAZOP) studies on chemical process plants are very time consuming, and often tedious, tasks. The requirement for HAZOP studies is that a team of experts systematically analyse every conceivable process deviation, identifying possible causes and any hazards that may result. The systematic nature of the task, and the fact that some team members may be unoccupied for much of the time, can lead to tedium, which in turn may lead to serious errors or omissions. An aid to HAZOP are fault trees, which present the system failure logic graphically such that the study team can readily assimilate their findings. Fault trees are also useful to the identification of design weaknesses, and may additionally be used to estimate the likelihood of hazardous events occurring. The one drawback of fault trees is that they are difficult to generate by hand. This is because of the sheer size and complexity of modern process plants. The work in this thesis proposed a computer-based method to aid the development of fault trees for chemical process plants. The aim is to produce concise, structured fault trees that are easy for analysts to understand. Standard plant input-output equation models for major process units are modified such that they include ancillary units and pipework. This results in a reduction in the nodes required to represent a plant. Control loops and protective systems are modelled as operators which act on process variables. This modelling maintains the functionality of loops, making fault tree generation easier and improving the structure of the fault trees produced. A method, called event ordering, is proposed which allows the magnitude of deviations of controlled or measured variables to be defined in terms of the control loops and protective systems with which they are associated.

Development of an electric heat pump for domestic use

This thesis records the design and development of an electrically driven, air to water, vapour compression heat pump of nominally 6kW heat output, for residential space heating. The study was carried out on behalf of GEC Research Ltd through the Interdisciplinary Higher Degrees Scheme at Aston University. A computer based mathematical model of the vapour compression cycle was produced as a design aid, to enable the effects of component design changes or variations in operating conditions to be predicted. This model is supported by performance testing of the major components, which revealed that improvements in the compressor isentropic efficiency offer the greatest potential for further increases in cycle COPh. The evaporator was designed from first principles, and is based on wire-wound heat transfer tubing. Two evaporators, of air side area 10.27 and 16.24m2, were tested in a temperature and humidity controlled environment, demonstrating that the benefits of the large coil are greater heat pump heat output and lower noise levels. A systematic study of frost growth rates suggested that this problem is most severe at the conditions of saturated air at 0oC combined with low condenser water temperature. A dynamic simulation model was developed to predict the in-service performance of the heat pump. This study confirmed the importance of an adequate radiator area for heat pump installations. A prototype heat pump was designed and manufactured, consisting of a hermetic reciprocating compressor, a coaxial tube condenser and a helically coiled evaporator, using Refrigerant 22. The prototype was field tested in a domestic environment for one and a half years. The installation included a comprehensive monitoring system. Initial problems were encountered with defrosting and compressor noise, both of which were solved. The unit then operated throughout the 1985/86 heating season without further attention, producing a COPh of 2.34.

Visual hallucinations in the Parkinsonian syndromes

Differential clinical diagnosis of the parkinsonian syndromes,viz., Parkinson's disease (PD), progressive supranuclear palsy (PSP), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and corticobasal degeneration (CBD) can be difficult. Visual hallucinations, however, are a chronic complication of some parkinsonian disorders and their presence may be a useful aid to diagnosis. The visual hallucinations in parkinsonism are often recurrent, well-formed, and detailed and occur in a significant proportion of cases of DLB and PD but are less common in PSP, MSA, and CBD. Hallucinations in PD often occur later in the disease and are complex, with flickering lights, and illusionary misconceptions often preceding the most common manifestation, viz., stereotypical colourful images. Hallucinations in DLB, however, are often present earlier in the disease and are similar to those in the 'misidentification syndromes', 'visual agnosias', and in 'delerium' but differ from those produced by hallucinogenic drugs such as LSD. Most typically in DLB, the hallucinations involve people or animals invading the patient's home but may also include inanimate objects and the appearance of writing on walls or ceilings. Visual hallucinations may involve a number of brain mechanisms including a change in the balance of neurotransmitter activity between the cholinergic and monoaminergic systems and may be a specific consequence of Lewy body (LB) pathology in brain stem nuclei. Ocular and retinal pathology may also contribute to hallucinations by reducing occipital stimulation. Hence, in patients with unclassifiable or with indeterminate parkinsonian symptoms, the presence of visual hallucinations should be regarded as a 'red flag' symptom indicating underlying Lewy body pathology and therefore, supporting a diagnosis of PD or DLB rather than PSP, MSA, or CBD. The presence of early visual hallucinations would support a diagnosis of DLB rather than PD. © 2013 Nova Science Publishers, Inc. All rights reserved.

A contingency theory perspective on the risk management control system within Birmingham City Council

In recent years the topic of risk management has moved up the agenda of both government and industry, and private sector initiatives to improve risk and internal control systems have been mirrored by similar promptings for change in the public sector. Both regulators and practitioners now view risk management as an integral part of the process of corporate governance, and an aid to the achievement of strategic objectives. The paper uses case study material on the risk management control system at Birmingham City Council to extend existing theory by developing a contingency theory for the public sector. The case demonstrates that whilst the structure of the control system fits a generic model, the operational details indicate that controls are contingent upon three core variables—central government policies, information and communication technology and organisational size. All three contingent variables are suitable for testing the theory across the broader public sector arena.

Eye movement problems and differential diagnosis of the parkinsonian syndromes

Differential clinical diagnosis of the parkinsonian syndromes, viz., Parkinson’s disease (PD), progressive supranuclear palsy (PSP), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA) can be difficult. Eye movement problems, however, are a chronic complication of many of these disorders and may be a useful aid to diagnosis. Hence, the presence in PSP of vertical supranuclear gaze palsy, fixation instability, lid retraction, blepharospasm, and apraxia of eyelid opening and closing is useful in separating PD from PSP. Moreover, atypical features of PSP include slowing of upward saccades, moderate slowing of downward saccades, the presence of a full range of voluntary vertical eye movements, a curved trajectory of oblique saccades, and absence of square-wave jerks. Downgaze palsy is probably the most useful diagnostic clinical symptom of PSP. By contrast, DLB patients are specifically impaired in both reflexive and saccadic execution and in the performance of more complex saccadic eye movement tasks. Problems in convergence in DLB are also followed by akinesia and rigidity. Abnormal ocular fixation may occur in a significant proportion of MSA patients along with excessive square-wave jerks, a mild supranuclear gaze palsy, a gaze-evoked nystagmus, a positioning down-beat nystagmus, mild-moderate saccadic hypometria, impaired smooth pursuit movements, and reduced vestibulo-ocular reflex (VOR) suppression. There may be considerable overlap between the eye movement problems characteristic of the various parkinsonian disorders, but taken together with other signs and symptoms, can be a useful aid in differential diagnosis, especially in the separation of PD and PSP.