26 resultados para on-site safety inspections

em Aston University Research Archive


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The thesis addresses the economic impacts of construction safety in Greece. The research involved the development of a methodology for determining the overall costs of safety, namely the sum of the costs of accidents and the costs of safety management failures (with or without accident) including image cost. Hitherto, very little work has been published on the cost of accidents in practical case studies. Moreover, to the author’s belief, no research has been published that seeks to determine in real cases the costs of prevention. The methodology developed is new, transparent, and capable of being replicated and adapted to other employment sectors and to other countries. The methodology was applied to three construction projects in Greece to test the safety costing methodology and to offer some preliminary evidence on the business case for safety. The survey work took place between 1999 and 2001 and involved 27 months of costing work on site. The study focuses on the overall costs of safety that apply to the main (principal) contractor. The methodology is supported by 120 discrete cost categories, and systematic criteria for determining which costs are included (counted) in the overall cost of safety. A quality system (in compliance with ISO9000 series) was developed to support the work and ensure accuracy of data gathering. The results of the study offer some support for the business case for safety. Though they offer good support for the economics of safety as they demonstrate need for cost effectiveness. Subject to important caveats, those projects that appeared to manage safety more cost-effectively achieved the lowest overall safety cost. Nevertheless, results are significantly lower than of other published works for two main reasons; first costs due to damages with no potential to injury were not included and second only costs to main constructor were considered. Study’s results are discussed and compared with other publish works.

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This research examines the effect of major changes, in the external context, on the safety culture of a UK generating company. It was focused on an organisation which was originally part of the state owned Central Electricity Generating Board and which, by the end of the research period, was a self-contained generating company, operating in a competitive market and a wholly owned subsidiary of a US utility. The research represents an attempt to identify the nature and culture of the original organisation and to identify, analyse and explain the effects of the forces of change in moulding the final organisation. The research framework employed a qualitative methodology to investigate the effects of change, supported by a safety culture questionnaire, based on factors identified in the third report of the ACSNI Human Factors Study Group; Organising for Safety, as being indicators of safety culture. An additional research objective was to assess the usefulness of the ACSNI factors as indicators of safety culture. Findings were that the original organisation was an engineering dominated technocracy with a technocentric safety culture. Values and beliefs were very strongly held and resistant to change and much of the original safety culture survived unchanged into the new organisation. The effects of very long periods of uncertainty about the future were damaging to management/worker relationships but several factors were identified which effectively insulated the organisation from any of the effects of change. The forces of change had introduced a beneficial appreciation of the crucial relationship between safety risk assessment and commercial risk assessment.Although the technical strength of the original safety culture survived, so did the essential weakness of a low level of appreciation of the human behavioural aspects of safety. This led to a limited, functionalist world view of safety culture, which assumed that cultural change was simpler to achieve than was the case and an inability to make progress in certain areas which were essentially behavioural problems.The factors identified by ACSNI provided a useful basis for the site research methodology and for identifying areas of relative strength and weakness in the site safety arrangements.

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Technological innovation has been widely studied: however surprisingly little is known about the experience of managing the process. Most reports tend to be generalistic and/or prescriptive whereas it is argued that multiple sources of variation in the process limit the value of these. A description of the innovation process is given together with a presentation of what is knovrn from existing studies. Gaps identified in this area suggest that a variety of organisational influences are important and an attempt is made to identify some of these at individual, group and organisational level. A simple system model of the innovation management process is developed. Further investigation of the influence of these factors was made possible through an extended on-site case study. Methodology for this based upon participant observation coupled wth a wide and flexible range of techniques is described. Evidence is presented about many aspects of the innovation process from a number of different levels and perspectives: the attempt is to demonstrate the extent to which variation due to contingent influences takes place. It is argued that problems identified all relate to the issue of integration. This theme is also developed from an analytical viewoint and it is suggested that organisational response to increases in complexity in the external environment will be to match them with internal complexity. Differentiation of this kind will require extensive and flexible integration, especially in those inherently uncertain areas associated with innovation. Whilst traditionally a function of management, it is argued that integration needs have increased to the point where a new specialism is required. The concept of integration specialist is developed from this analysis and attempts at simple integrative change during the research are described. Finally a strategy for integration - or rather for building in integrative capability - ln the organisation studied is described.

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Whole life costing (WLC) has become the best practice in construction procurement and it is likely to be a major issue in predicting whole life costs of a construction project accurately. However, different expectations from different organizations throughout a project's life and the lack of data, monitoring targets, and long-term interest for many key players are obstacles to be overcome if WLC is to be implemented. A questionnaire survey was undertaken to investigate a set of ten common factors and 188 individual factors. These were grouped into eight critical categories (project scope, time, cost, quality, contract/administration, human resource, risk, and health and safety) by project phase, as perceived by the clients, contractors and subcontractors in order to identify critical success factors for whole life performance assessment (WLPA). Using a relative importance index, the top ten critical factors for each category, from the perspective of project participants, were analyzed and ranked. Their agreement on those categories and factors were analyzed using Spearman's rank correlation. All participants identify “Type of Project” as the most common critical factor in the eight categories for WLPA. Using the relative index ranking technique and weighted average methods, it was found that the most critical individual factors in each category were: “clarity of contract” (scope); “fixed construction period” (time); “precise project budget estimate” (cost); “material quality” (quality); “mutual/trusting relationships” (contract/administration); “leadership/team management” (human resource); and “management of work safety on site” (health and safety). There was relatively a high agreement on these categories among all participants. Obviously, with 80 critical factors of WLPA, there is a stronger positive relationship between client and contactor rather than contractor and subcontractor, client and subcontractor. Putting these critical factors into a criteria matrix can facilitate an initial framework of WLPA in order to aid decision making in the public sector in South Korea for evaluation/selection process of a construction project at the bid stage.

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The thesis addresses the relative importance of factors affecting working-class school-leavers' post-compulsory education transitions into post-sixteen education, training, employment and unemployment. It focuses on school-leavers choosing to enter the labour market, whether successfully or not and the influences affecting this choice. Methodologically, the longitudinal approach followed young people from before they left school to a period of months after. Discrepancies between young people's intended and actual destinations emphasised the diverse influences on post-sixteen transitions. These influences were investigated through a dynamic multi-method approach, drawing from quantitative and qualitative methodologies providing depth and insight while locating the research within a structural framework, allowing a comparison with local and national trends. Two crucial factors of school and gender affected young people's intended and actual post-sixteen directions. School policy, including treatment of disaffected pupils and recruitment to a large, on-site sixth form, influenced the number of pupils opting to continue their education. Girls were more likely to continue education after the end of compulsory schooling and gave different reasons to boys for doing so. Family and peer groups were influential, helping young people develop a 'horizon for action' incorporating habitus and subjective preferences that specified acceptable post-sixteen directions. These influences operated within the context of the local labour market. Perception of the latter rather than actual conditions informed post-sixteen decisions; however, labour market reality influenced the success of the school-leavers' endeavours. The research found that the economics-based rational choice model of decision-making did not apply to many working class school-leavers. The cohort made pragmatically rational decisions dependent on their 'horizon for action'. based on partial, occasionally inaccurate information. Policy recommendations consider the careers service and structure or school sixth forms as aiding successful transitions from compulsory education into education, employment or training. The maintenance allowance may be ineffectual in tackling its objective of social inclusion.

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Off-highway motive plant equipment is costly in capital outlay and maintenance. To reduce these overheads and increase site safety and workrate, a technique of assessing and limiting the velocity of such equipment is required. Due to the extreme environmental conditions met on such sites, conventional velocity measurement techniques are inappropriate. Ogden Electronics Limited were formed specifically to manufacture a motive plant safety system incorporating a speed sensor and sanction unit; to date, the only such commercial unit available. However, problems plague the reliability, accuracy and mass production of this unit. This project assesses the company's exisiting product, and in conjunction with an appreciation of the company history and structure, concludes that this unit is unsuited to its intended application. Means of improving the measurement accuracy and longevity of this unit, commensurate with the company's limited resources and experience, are proposed, both for immediate retrofit and for longer term use. This information is presented in the form of a number of internal reports for the company. The off-highway environment is examined; and in conjunction with an evaluation of means of obtaining a returned signal, comparisons of processing techniques, and on-site gathering of previously unavailable data, preliminary designs for an alternative product are drafted. Theoretical aspects are covered by a literature review of ground-pointing radar, vehicular radar, and velocity measuring systems. This review establishes and collates the body of knowledge in areas previously considered unrelated. Based upon this work, a new design is proposed which is suitable for incorporation into the existing company product range. Following production engineering of the design, five units were constructed, tested and evaluated on-site. After extended field trials, this design has shown itself to possess greater accuracy, reliability and versatility than the existing sensor, at a lower unit cost.

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Intelligent transport system (ITS) has large potentials on road safety applications as well as nonsafety applications. One of the big challenges for ITS is on the reliable and cost-effective vehicle communications due to the large quantity of vehicles, high mobility, and bursty traffic from the safety and non-safety applications. In this paper, we investigate the use of dedicated short-range communications (DSRC) for coexisting safety and non-safety applications over infrastructured vehicle networks. The main objective of this work is to improve the scalability of communications for vehicles networks, ensure QoS for safety applications, and leave as much as possible bandwidth for non-safety applications. A two-level adaptive control scheme is proposed to find appropriate message rate and control channel interval for safety applications. Simulation results demonstrated that this adaptive method outperforms the fixed control method under varying number of vehicles. © 2012 Wenyang Guan et al.

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Importance of the field: Tacrolimus is the most commonly used immunosuppressive agent following solid-organ transplantation in children. Its clinical use, however, is complicated by side effects (mainly nephrotoxicity), narrow therapeutic index and pharmacokinetic variability which can result in an increased risk of treatment failure or toxicity. Studies examining interindividual differences in the expression of the ABCB1 (ATP-binding cassette, subfamily B, member 1) gene (which encodes the drug transporter, P-gp) and its genetic polymorphisms have attempted to elucidate variations in tacrolimus response and disposition in children. Areas covered in this review: This review explores pharmacogenetic knowledge developed over the last decade regarding the impact of ABCB1 polymorphisms on tacrolimus toxicity and dosage requirements in children. What the reader will gain: A better understanding of the role of ABCB1 genetic polymorphisms (and corresponding haplotypes) and ABCB1 expression levels in various tissues and organs on tacrolimus outcomes in children with liver transplant. Take home message: Pharmacogenetics offers significant potential for optimising tacrolimus use. ABCB1 donor genotypes and ABCB1 expression level in the intestine and leukocytes may be useful in dosage selection. Large prospective studies are, however, required to further explore the potential of genetic testing in identifying children who are at risk of toxicity and to better individualise tacrolimus therapy.

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Introduction: The use of intravitreal ranibizumab has transformed the outcomes for thousands of patients with wet age related macular degeneration (AMD), which is the leading cause of blindness in developed countries. Prior to its introduction, most patients with wet AMD would rapidly lose central vision. The use of intravitreal ranibizumab has been shown to reduce certifiable visual loss by about a half. Current treatment regimens with ranibizumab in wet AMD require multiple injections over several years and so it is highly relevant to review the safety record of this important drug.Areas covered: This review considers the important ocular and systemic adverse events (AE) that have been reported in the literature, particularly in the context of the pivotal clinical trials that have been performed. It also reviews the safety of other anti-VEGF drugs that are used in wet AMD, namely bevacizumab and aflibercept, and compares these drugs with ranibizumab.Expert opinion: Overall, intravitreal ranibizumab can be considered a safe and highly effective drug for patients with wet AMD. However recent concerns about retinal thinning following ranibizumab therapy, possible systemic AE associated with all anti-VEGF drugs and the occurrence of complications relating to drug preparation and delivery must be considered. © 2014 Informa UK, Ltd.

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This article presents a new method for data collection in regional dialectology based on site-restricted web searches. The method measures the usage and determines the distribution of lexical variants across a region of interest using common web search engines, such as Google or Bing. The method involves estimating the proportions of the variants of a lexical alternation variable over a series of cities by counting the number of webpages that contain the variants on newspaper websites originating from these cities through site-restricted web searches. The method is evaluated by mapping the 26 variants of 10 lexical variables with known distributions in American English. In almost all cases, the maps based on site-restricted web searches align closely with traditional dialect maps based on data gathered through questionnaires, demonstrating the accuracy of this method for the observation of regional linguistic variation. However, unlike collecting dialect data using traditional methods, which is a relatively slow process, the use of site-restricted web searches allows for dialect data to be collected from across a region as large as the United States in a matter of days.

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This paper presents a surrogate-model-based optimization of a doubly-fed induction generator (DFIG) machine winding design for maximizing power yield. Based on site-specific wind profile data and the machine's previous operational performance, the DFIG's stator and rotor windings are optimized to match the maximum efficiency with operating conditions for rewinding purposes. The particle swarm optimization-based surrogate optimization techniques are used in conjunction with the finite element method to optimize the machine design utilizing the limited available information for the site-specific wind profile and generator operating conditions. A response surface method in the surrogate model is developed to formulate the design objectives and constraints. Besides, the machine tests and efficiency calculations follow IEEE standard 112-B. Numerical and experimental results validate the effectiveness of the proposed technologies.

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This paper reports the initial results of a joint research project carried out by Aston University and Lloyd's Register to develop a practical method of assessing neural network applications. A set of assessment guidelines for neural network applications were developed and tested on two applications. These case studies showed that it is practical to assess neural networks in a statistical pattern recognition framework. However there is need for more standardisation in neural network technology and a wider takeup of good development practice amongst the neural network community.

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In an exploding and fluctuating construction market, managers are facing a challenge, which is how to manage business on a wider scale and to utilize modern developments in information technology to promote productivity. The extraordinary development of telecommunications and computer technology makes it possible for people to plan, lead, control, organize and manage projects from a distance without the need to be on site on a daily basis. A modern management known as distance management (DM) or remote management is emerging. Physical distance no longer determines the boundary of management since managers can now operate projects through virtual teams that organize manpower, material and production without face-to-face communication. What organization prototype could overcome psychological and physical barriers to reengineer a successful project through information technology? What criteria distinguishes the adapted way of communication of individual activities in a teamwork and assist the integration of an efficient and effective communication between face-to-face and a physical distance? The entire methodology has been explained through a case application on refuse incineration plant projects in Taiwan.

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This thesis describes an industrial research project carried out in collaboration with STC Components, Harlow, Essex. Technical and market trends in the use of surface acoustic wave (SAW) devices are reviewed. As a result, three areas not previously addressed by STC were identified: lower insertion loss designs, higher operating frequencies and improved temperature dependent stability. A review of the temperature performance of alternative lower insertion loss designs,shows that greater use could be made of the on-site quartz growing plant. Data is presented for quartz cuts in the ST-AT range. This data is used to modify the temperature performance of a SAW filter. Several recently identified quartz orientations have been tested. These are SST, LST and X33. Problems associated with each cut are described and devices demonstrated. LST quartz, although sensitive to accuracy of cut, is shown to have an improved temperature coefficient over the normal ST orientation. Results show that its use is restricted due to insertion loss variations with temperature. Effects associated with split-finger transducers on LST-quartz are described. Two low-loss options are studied, coupled resonator filters for very narrow bandwidth applications and single phase unidirectional transducers (SPUDT) for fractional bandwidths up to about 1%. Both designs can be implemented with one quarter wavelength transducer geometries at operating frequencies up to 1GHz. The SPUDT design utilised an existing impulse response model to provide analysis of ladder or rung transducers. A coupled resonator filter at 400MHz is demonstrated with a matched insertion loss of less than 3.5dB and bandwidth of 0.05%. A SPUDT device is designed as a re-timing filter for timing extraction in a long haul PCM transmission system. Filters operating at 565MHz are demonstrated with insertion losses of less than 6dB. This basic SPUDT design is extended to a maximally distributed version and demonstrated at 450MHz with 9.8dB insertion loss.

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Much research is currently centred on the detection of damage in structures using vibrational data. The work presented here examined several areas of interest in support of a practical technique for identifying and locating damage within bridge structures using apparent changes in their vibrational response to known excitation. The proposed goals of such a technique included the need for the measurement system to be operated on site by a minimum number of staff and that the procedure should be as non-invasive to the bridge traffic-flow as possible. Initially the research investigated changes in the vibrational bending characteristics of two series of large-scale model bridge-beams in the laboratory and these included ordinary-reinforced and post-tensioned, prestressed designs. Each beam was progressively damaged at predetermined positions and its vibrational response to impact excitation was analysed. For the load-regime utilised the results suggested that the infuced damage manifested itself as a function of the span of a beam rather than a localised area. A power-law relating apparent damage with the applied loading and prestress levels was then proposed, together with a qualitative vibrational measure of structural damage. In parallel with the laboratory experiments a series of tests were undertaken at the sites of a number of highway bridges. The bridges selected had differing types of construction and geometric design including composite-concrete, concrete slab-and-beam, concrete-slab with supporting steel-troughing constructions together with regular-rectangular, skewed and heavily-skewed geometries. Initial investigations were made of the feasibility and reliability of various methods of structure excitation including traffic and impulse methods. It was found that localised impact using a sledge-hammer was ideal for the purposes of this work and that a cartridge `bolt-gun' could be used in some specific cases.