987 resultados para Safety engineering.


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Crashes that occur on motorways contribute to a significant proportion (40-50%) of non-recurrent motorway congestion. Hence, reducing the frequency of crashes assist in addressing congestion issues (Meyer, 2008). Analysing traffic conditions and discovering risky traffic trends and patterns are essential basics in crash likelihood estimations studies and still require more attention and investigation. In this paper we will show, through data mining techniques, that there is a relationship between pre-crash traffic flow patterns and crash occurrence on motorways, compare them with normal traffic trends, and that this knowledge has the potentiality to improve the accuracy of existing crash likelihood estimation models, and opens the path for new development approaches. The data for the analysis was extracted from records collected between 2007 and 2009 on the Shibuya and Shinjuku lines of the Tokyo Metropolitan Expressway in Japan. The dataset includes a total of 824 rear-end and sideswipe crashes that have been matched with crashes corresponding traffic flow data using an incident detection algorithm. Traffic trends (traffic speed time series) revealed that crashes can be clustered with regards to the dominant traffic patterns prior to the crash occurrence. K-Means clustering algorithm applied to determine dominant pre-crash traffic patterns. In the first phase of this research, traffic regimes identified by analysing crashes and normal traffic situations using half an hour speed in upstream locations of crashes. Then, the second phase investigated the different combination of speed risk indicators to distinguish crashes from normal traffic situations more precisely. Five major trends have been found in the first phase of this paper for both high risk and normal conditions. The study discovered traffic regimes had differences in the speed trends. Moreover, the second phase explains that spatiotemporal difference of speed is a better risk indicator among different combinations of speed related risk indicators. Based on these findings, crash likelihood estimation models can be fine-tuned to increase accuracy of estimations and minimize false alarms.

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Increasing the modal share of public transit systems has become paramount in aiding the reduction on the excessive reliance of personal motor vehicles. More so the need to increase the share of active modes of transport such as the use of bicycles, therefore there is an ever increasing need to use bicycles both on shared pedestrian paths and on-road cycling. The risk to cyclist, or consequently the perception of the risk from both cyclists and motorists alike, is an important factor to increase the use of this transport mode. This paper investigates perception of bicycle safety by conducting a survey and analysing the survey data to understand how participants with different backgrounds perceive the risks of cycling for transport. Contributing factors to people’s perception of bicycle safety were identified and compared across different road user groups, based upon which recommendations were made on how to improve bicycle safety.

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There is a continuing need to improve safety at Railway Level Crossings (RLX) particularly those that do not have gates and lights regulating traffic flow. A number of Intelligent Transport System (ITS) interventions have been proposed to improve drivers’ awareness and reduce errors in detecting and responding appropriately at level crossings. However, as with other technologies, successful implementation and ultimately effectiveness rests with the acceptance of the technology by the end user. In the current research, four focus groups were held (n=38) with drivers in metropolitan and regional locations in Queensland to examine their perceptions of potential in-vehicle and road-based ITS interventions to improve safety at RLX. The findings imply that further development of the ITS interventions, in particular the design and related promotion of the final product, must consider ease of use, usefulness and relative cost.

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BACKGROUND Research on engineering design is a core area of concern within engineering education and a fundamental understanding of how engineering students approach and undertake design is necessary in order to develop effective design models and pedagogies. Understanding the factors related to design experiences in education and how they affect student practice can help educators as well as designers to leverage these factors as part of the design process. PURPOSE This study investigated the design practices of first-year engineering students’ and their experiences with a first-year engineering course design project. The research questions that guided the investigation were: 1. From a student perspective, what design parameters or criteria are most important? 2. How does this perspective impact subsequent student design practice throughout the design process? DESIGN/METHOD The authors employed qualitative multi-case study methods (Miles & Huberman, 1994) in order to the answer the research questions. Participant teams were observed and video recorded during team design meetings in which they researched the background for the design problem, brainstormed and sketched possible solutions, as well as built prototypes and final models of their design solutions as part of a course design project. Analysis focused on explanation building (Yin, 2009) and utilized within-case and cross-case analysis (Miles & Huberman, 1994). RESULTS We found that students focused disproportionally on the functional parameter, i.e. the physical implementation of their solution, and the possible/applicable parameter, i.e. a possible and applicable solution that benefited the user, in comparison to other given parameters such as safety and innovativeness. In addition, we found that individual teams focused on the functional and possible/ applicable parameters in early design phases such as brainstorming/ ideation and sketching. When prompted to discuss these non-salient parameters (from the student perspective) in the final design report, student design teams often used a post-hoc justification to support how the final designs fit the parameters that they did not initially consider. CONCLUSIONS This study suggests is that student design teams become fixated on (and consequently prioritize) certain parameters they interpret as important because they feel these parameters were described more explicitly in terms how they were met and assessed. Students fail to consider other parameters, perceived to be less directly assessable, unless prompted to do so. Failure to consider other parameters in the early design phases subsequently affects their approach in design phases as well. Case studies examining students’ study strategies within three Australian Universities illustrate similarities with some student approaches to design.

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The introduction of safety technologies into complex socio-technical systems requires an integrated and holistic approach to HF and engineering, considering the effects of failures not only within system boundaries, but also at the interfaces with other systems and humans. Level crossing warning devices are examples of such systems where technically safe states within the system boundary can influence road user performance, giving rise to other hazards that degrade safety of the system. Chris will discuss the challenges that have been encountered to date in developing a safety argument in support of low-cost level crossing warning devices. The design and failure modes of level crossing warning devices are known to have a significant influence on road user performance; however, quantifying this effect is one of the ongoing challenges in determining appropriate reliability and availability targets for low-cost level crossing warning devices.

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Repair, maintenance, minor alteration, and addition work (RMAA) has become more and more important in developed societies, but its safety performance is alarming. For example, RMAA projects accounted for 53.2% of the total construction market and the percentage of RMAA accidents to all construction accidents in the Hong Kong Special Administrative Region (HKSAR) increased considerably in 2007. The RMAA sector has a huge potential for safety improvement. This study aims to explore and evaluate the difficulties of implementing safety practices in RMAA work. The mixed methods approach was adopted, and semistructured interviews and a two-round Delphi survey were conducted for the data collection. Major difficulties were identified, including limited safety resources for small and medium enterprises (SMEs), difficulty in changing the mindset of RMAA workers, and difficulty in performing safety supervision. These obstacles for implementing safety practices in the RMAA sector, if successfully removed, could significantly improve the safety performance of the RMAA sector and the construction industry as a whole.

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Safety of repair, maintenance, alteration, and addition (RMAA) works have long been neglected because RMAAworks are often minute and only last for a short period of time. With rising importance of the RMAA sector in many developed societies, safety of RMAA works has begun to draw attention. Many RMAA contracting companies are small- and medium-sized enterprises (SMEs) that do not have comprehensive safety management systems. Existing safety legislation and regulations for new construction sites are not fully applicable to RMAAworks. Instead of relying on explicit and well-established safety systems, tacit safety knowledge plays an extremely important role in RMAA projects. To improve safety of RMAAworks, safety knowledge should be better managed. However, safety knowledge is difficult to capture in RMAA works. This study aims to examine safety management practices of RMAA contracting companies to see how safety knowledge of RMAA projects is managed. Findings show that RMAA contracting companies undertaking large-scale RMAA projects have more initiatives of safety management. Safety management of small-scale RMAA works relies heavily on the motivation of site supervisors and self-regulation of workers. Better tacit knowledge management improves safety performance. To enhance safety capability of RMAA contracting companies, a knowledge sharing culture should be cultivated. The government should provide assistance to SMEs to implement proper safety management practices in small-sized projects. Potentials of applying computer software technology in RMAA projects to capture, store, and retrieve safety information should be explored. Employees should be motivated to share safety knowledge by giving proper recognition to those who are willing to share.

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Purpose The repair, maintenance, minor alteration and addition (RMAA) sector has been expanding in many developed cities. Safety problems of the RMAA sector have attracted the attention of many governments. This study has the objectives of comparing the level of safety climate of workers, supervisors and managers in the RMAA sector; and explaining/ predicting the impact of safety climate on injury occurrence of workers, supervisors and managers. Design/methodology/approach A questionnaire survey was administered to RMAA contracting companies in Hong Kong. Findings When comparing the safety climate perception of workers, supervisors and managers in the RMAA sector, the supervisors group had the lowest mean safety climate score. Results showed that a positive workforce safety attitude and acceptance of safety rules and regulations reduced the workers’ likelihood of having injuries. A reasonable production schedule led to a lower probability of supervisors being injured. Management commitment and effective safety management reduced the probability of managers being injured. Originality/value This study revealed variations of safety climate at the different levels in the organizational hierarchy and their varying influence on safety performance of the RMAA sector. Safety of RMAA works could be improved by promulgating specific safety measures at the different hierarchy levels.

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The importance of repair, maintenance, minor alteration, and addition (RMAA) works is increasing in many built societies. When the volume of RMAA works increases, the occurrence of RMAA accidents also increases. Safety of RMAA works deserves more attention; however, research in this important topic remains limited. Safety climate is considered a key factor that influences safety performance. The present study aims to determine the relationships between safety climate and safety performance of RMAA works, thereby offering recommendations on improving RMAA safety. Questionnaires were dispatched to private property management companies, maintenance sections of quasi-government developers and their subcontractors, RMAA sections of general contractors, small RMAA contractors, building services contractors and trade unions in Hong Kong. In total, data from 396 questionnaires were collected from RMAA workers. The sample was divided into two equal-sized sub-samples. On the first sub-sample SEM was used to test the model, which was validated on the second sub-sample. The model revealed a significant negative relationship between RMAA safety climate and incidence of self-reported near misses and injuries, and significant positive relationships between RMAA safety climate and safety participation and safety compliance respectively. Higher RMAA safety climate was positively associated with a lower incidence of self-reported near misses and injuries and higher levels of safety participation and safety compliance.

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The accident record of the repair, maintenance, minor alteration, and addition (RMAA) sector has been alarmingly high; however, research in the RMAA sector remains limited. Unsafe behavior is considered one of the key causes of accidents. Thus, the organizational factors that influence individual safety behavior at work continue to be the focus of many studies. The safety climate, which reflects the true priority of safety in an organization, has drawn much attention. Safety climate measurement helps to identify areas for safety improvement. The current study aims to identify safety climate factors in the RMAA sector. A questionnaire survey was conducted in the RMAA sector in Hong Kong. Data were randomly split into the calibration and the validation samples. The RMAA safety climate factors were determined by exploratory factor analysis on the calibration sample. Three safety climate factors of the RMAA works were identified: (1) management commitment to occupational health and safety (OHS) and employee involvement, (2) application of safety rules and work practices, and; (3) responsibility for health and safety. Confirmatory factor analysis (CFA) was then conducted on the validation sample. The CFA model showed satisfactory goodness of fit, reliability, and validity. The suggested RMAA safety climate factors can be utilized by construction industry practitioners in developed economies to measure the safety climate of their RMAA projects, thereby enhancing the safety of RMAA works.

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Purpose Managing and maintaining infrastructure assets are one of the indispensible tasks for many government agencies to preserve the nations' economic viability and social welfare. To reduce the expenditures over the life-cycle of an infrastructure asset and extend the period for which the asset performs effectively, proper repair and maintenance are essential. While repair, maintenance, minor alteration and addition (RMAA) sector is expanding in many developed cities, occurrences of fatalities and injuries in this sector are also soaring. The purposes of this paper are to identify and then evaluate the various strategies for improving the safety performance of RMAA works. Design/methodology/approach Semi-structured interviews and two rounds of Delphi survey were conducted for data collection. Findings Raising safety awareness of RMAA workers and selecting contractors with a good record of safety performance are the two most important strategies to improve the safety performance in this sector. Technology innovations and a pay-for-safety scheme are regarded as the two least important strategies. Originality/value The paper highlights possible ways to enhance safety of the rather under-explored RMAA sector in the construction industry.

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This paper presents the blast response, damage mechanism and evaluation of residual load capacity of a concrete–steel composite (CSC) column using dynamic computer simulation techniques. This study is an integral part of a comprehensive research program which investigated the vulnerability of structural framing systems to catastrophic and progressive collapse under blast loading and is intended to provide design information on blast mitigation and safety evaluation of load bearing vulnerable columns that are key elements in a building. The performance of the CSC column is compared with that of a reinforced concrete (RC) column with the same dimensions and steel ratio. Results demonstrate the superior performance of the CSC column, compared to the RC column in terms of residual load carrying capacity, and its potential for use as a key element in structural systems. The procedure and results presented herein can be used in the design and safety evaluation of key elements of multi-storey buildings for mitigating the impact of blast loads.

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Gross value of cons truction work in the repair , maintenance, minor alte ration and addition (RMAA) sector in Hong Kong has expanded dramatically by 58% from 1998 to 2007, accounting for over 53% of the whole construction market in 2007. Unfortunately, the portion of industrial accidents arising from this sector also increased substantially during the same period. It is important to improve the safety performance of the RMAA sector. This paper has set out the objectives to examine safety statistics of RMAA works; to compare them with those of green field projects; and more importantly, to highlight potential hurdles en countered in the process of comparison and finally to provide effective recommendations for overcoming these impediments. To strive for continuous safety improvement of RMAA works, comparable safety statistics should be compiled for this sector.

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Safety has long been a problem in the construction industry. Repair, maintenance, alteration and addition (RMAA) sector has emerged to play an important role in the construction industry. It accounted for 53% of the total construction market in Hong Kong in 2007. Safety performance of the RMAA words has been alarming. Statistics indicate that the percentage of fatal industrial accidents arising from RMAA work in Hong Kong was over 56% in 2006 while the remaining 44% was from new works. Effective safety measures to address the safety problems and improve safety performance of the RMAA sector are urgently needed. Unsafe behaviour has been attributed to one of the major causes of accidents. Traditional cost-benefit analysis of workers' safety behaviour seems to be inadequate. This paper proposes to adopt a game theoretical approach to analyse safety behaviour of RMAA workers. Game theory is concerned with the decision-making process in situations where outcomes depend upon choices made by one or more players. A game theoretical model between contractor and worker has been proffered. Mathematical analysis of this game model has been done and implications of the analysis have been discussed.

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The construction industry of Hong Kong is experiencing an ageing problem and a labour shortage. To alleviate the shortage of construction workforce, the government has initiatives to assist ethnic minorities to join the construction industry. It is foreseeable that more people from the ethnic minorities will join the construction industry. The safety of workers from the ethnic minorities in construction has attracted growing research interest in many developed countries. Statistics show that workers from the ethnic minorities were nearly 30 percent more likely to have work-related injuries than local workers. However, in Hong Kong, official statistics on the safety of workers from the ethnic minorities are not available. This reflects the racial or ethnic insensitivity of the construction industry in Hong Kong. As the safety of ethnic minorities has not received the attention, this research seeking to contribute to efforts to improve the safety of workers from the ethnic minorities in the construction industry of Hong Kong is all the more urgent. This paper provides an initial report of a research project which focuses on improving the safety of ethnic minority construction workers. Qualitative and quantitative research methods applied in conducting the research are first discussed. Preliminary statistics of construction accidents involving ethnic minority construction workers will then be reported.