Evaluating management commitment to health and safety in small and medium construction enterprises

Construction health and safety (H&S) in small and medium construction enterprises (SMEs) has received little attention in South Africa, in terms of either research or support for preventive initiatives. Previous research suggests that this sector has serious problems exacerbated by limited access to human, economic and technological resources. Moreover it is now recognized that methods developed specifically for large firms cannot necessarily be transferred to smaller and medium firms, hence the need to investigate management commitment to H&S among SMEs

Construction health and safety culture in South African small and medium enterprises

Construction health and safety (H&S) culture in small and medium construction enterprises (SMEs) has received little attention in South Africa, in terms of either research or support for preventive initiatives. Previous research suggests that this sector has serious problems exacerbated by limited access to human, economic and technological resources. Moreover it is now recognized that methods developed specifically for large firms cannot necessarily be transferred to smaller and medium firms, hence the need to investigate the H&S culture in SMEs. This exploratory study is based on descriptive survey using semi-structured and structured questionnaire, and non-probability sampling to give an overview of the characteristics of H&S culture and practices in SMEs firms in the South African construction industry

Validating and identifying health and safety performance improvement indicators : experience of using Delphi technique

Abstract: The literature on health and safety (H&S) is bound with different elements and indicators of measuring H&S performance. The purpose of this paper is to discuss the success and challenges of using quantitative and qualitative approach of Delphi technique in validating and identifying H&S performance indicators that small and medium construction enterprises (SMEs) can use to measure and monitor their H&S performance improvement at project level. Furthermore, discuss the identification of experts in the field of H&S, ways of improving consensus analysis and minimizing experts’ non‐response. This study is based on practical experience of the researchers pertaining to the Delphi technique method which is a constructivist or interpretive approach to knowledge. The study started with an extensive literature review to identify core elements and leading indicators characterizing H&S culture to develop a Delphi questionnaire that was used in the first round of Delphi. A four round Delphi technique was conducted to attain consensus of the identified H&S indicators. The experts were identified from published articles of H&S, practitioners’ website of H&S and word of mouth. The use of email was used as a mode of communication. This study set to warn but also encourage the use of Delphi technique as a method to unearth information in areas where consensus has not been reached such as H&S performance measurement indicators for construction SMEs in South Africa

Critical indicators for measuring health and safety performance improvement in small and medium construction enterprise projects

The common measures of measuring health and safety (H&S) performance have, been down stream indicators. Such measures alone are regarded as inadequate in providing meaningful information to help reduce the cause of workplace injury or illness. Researchers have indicated that there is no consensus on what constitutes appropriate H&S performance indicators. This study sought to validate the identified set of leading indicators to enable personnel of small and medium construction enterprises (SME) monitor and improve H&S performance on their projects

Identification of health and safety performance improvement indicators for small and medium construction enterprises : a Delphi consensus study

This study sought to identify and validate a comprehensive set of health and safety (H&S) leading indicator metrics that will enable small and medium construction enterprises (SMEs) personnel to monitor the level of H&S performance in their projects. The Delphi approach was used where the opinion of H&S experts, academics and industry practitioners were canvassed on 64 potential indicator metrics, categorized in 10 elements or leading indicators that will enable H&S performance improvement e.g. reduction in accidents, injuries, diseases but to name a few. The experts rated each indicator metric on a 10-point Likert scale of impact, where 1= no major impact or 10% impact and 10 = major impact or 100% impact. Consensus was reached on 32 indicator metrics after four successive rounds of Delphi if the indicators attracted final scores of, percentage median impact of 90% to 100% which is 9.00 to 10.00 median rating and over 50% of respondents rating the indicator metrics in the band of 9.00 to 10.00 or 90% to 100% impact to improve H&S performance. The experts had the opportunity to reconsider their scores informed by the group median score in rounds 2, 3 and 4. The limitation of the study was the reliance of a structured questionnaire in the first round as experts were not allowed to add any new indicators, until the fourth round. This study contributes to the H&S body of knowledge where no consensus has been reached pertaining to the indicator metrics that have major impact to improve H&S performance at project level of construction SMEs in South Africa

The implementation of health and safety practices : do demographic attributes matter?

The purpose of this study was to investigate the personnel attributes perception on reliable and valid health and safety (H&S) practices within small- and medium-sized construction enterprises (SMEs) in South Africa. It explores whether these valid and reliable H&S practices could be implemented based on the demographic attributes, namely, years of experience in the construction industry, number of years working in the current organisation and educational level. Design/methodology/approach – A mixed method approach was used to conduct this research, namely, Delphi and questionnaire survey. A structured questionnaire consisting of 31 H&S practices categorised into five major H&S practices was developed from extensive literature review and the participation of 20 purposive sampled H&S experts. Sixteen H&S experts completed four iterations. A convenient sample of 1,450 SMEs was obtained. In total, 228 questionnaires were returned, of which 216 responses were useable for analysis. The data were analysed using exploratory factor analysis and confirmatory factor analysis to determine the validity, reliability and acceptability of theH&Spractices. Finally, one-wayANOVAand t-test were conducted to determine personnel attributes perception on the implementation of the H&S practices. Findings – The five major H&S practices (constructs), namely, upper management commitment and involvement in H&S, employee involvement and empowerment in H&S, project supervision, project H&S planning and communication in H&S and H&S resources and training, were retained as reliable and valid practices of H&S within construction SMEs at project level. One-way ANOVA established no statistical significant difference on the respondents’ perception of the H&S practices. However, t-test revealed statistically significant difference on the respondents’ perception on, upper management commitment and involvement in H&S and H&S resources and training. The respondents with post-matric qualification strongly agreed that upper management are committed and involved in H&S. Originality/value – The findings may help construction SMEs to use these H&S practices to manage H&S in their projects. The SMEs may also consider the level of education of their personnel when implementing H&S practices of upper management and H&S resources and training

Optimal design of nanoplasmonic materials using genetic algorithms as a multi-parameter optimization tool

An optimal control approach based on multiple parameter genetic algorithms is applied to the design of plasmonic nanoconstructs with pre-determined optical properties and functionalities. We first develop nanoscale metallic lenses that focus an incident plane wave onto a pre-specified, spatially confined spot. Our results illustrate the role of symmetry breaking and unravel the principles that favor dimeric constructs for optimal light localization. Next we design a periodic array of silver particles to modify the polarization of an incident, linearly-polarized plane wave in a desired fashion while localizing the light in space. The results provide insight into the structural features that determine the birefringence properties of metal nanoparticles and their arrays. Of the variety of potential applications that may be envisioned, we note the design of nanoscale light sources with controllable coherence and polarization properties that could serve for coherent control of molecular or electronic dynamics in the nanoscale.Comment: 13 pages, 6 figures. submitted to J. Chem. Phy

Anomalous suppression of the shot noise in a nanoelectromechanical system

In this paper we report a relaxation-induced suppression of the noise for a single level quantum dot coupled to an oscillator with incoherent dynamics in the sequential tunneling regime. It is shown that relaxation induces qualitative changes in the transport properties of the dot, depending on the strength of the electron-phonon coupling and on the applied voltage. In particular, critical thresholds in voltage and relaxation are found such that a suppression below 1/2 of the Fano factor is possible. Additionally, the current is either enhanced or suppressed by increasing relaxation, depending on bias being greater or smaller than the above threshold. These results exist for any strength of the electron-phonon coupling and are confirmed by a four states toy model.Comment: 7 pages, 7 eps figures, submitted to PRB; minor changes in the introductio

RF-MEMS switch actuation pulse optimization using Taguchi's method

Copyright @ 2011 Springer-VerlagReliability and longevity comprise two of the most important concerns when designing micro-electro-mechanical-systems (MEMS) switches. Forcing the switch to perform close to its operating limits underlies a trade-off between response bandwidth and fatigue life due to the impact force of the cantilever touching its corresponding contact point. This paper presents for first time an actuation pulse optimization technique based on Taguchi’s optimization method to optimize the shape of the actuation pulse of an ohmic RF-MEMS switch in order to achieve better control and switching conditions. Simulation results show significant reduction in impact velocity (which results in less than 5 times impact force than nominal step pulse conditions) and settling time maintaining good switching speed for the pull down phase and almost elimination of the high bouncing phenomena during the release phase of the switch

Synergistic Formation of Radicals by Irradiation with Both Vacuum Ultraviolet and Atomic Hydrogen: A Real-Time In Situ Electron Spin Resonance Study

We report on the surface modification of polytetrafluoroethylene (PTFE) as an example of soft- and bio-materials that occur under plasma discharge by kinetics analysis of radical formation using in situ real-time electron spin resonance (ESR) measurements. During irradiation with hydrogen plasma, simultaneous measurements of the gas-phase ESR signals of atomic hydrogen and the carbon dangling bond (C-DB) on PTFE were performed. Dynamic changes of the C-DB density were observed in real time, where the rate of density change was accelerated during initial irradiation and then became constant over time. It is noteworthy that C-DBs were formed synergistically by irradiation with both vacuum ultraviolet (VUV) and atomic hydrogen. The in situ real-time ESR technique is useful to elucidate synergistic roles during plasma surface modification.Comment: 14 pages, 4 figure