57 research outputs found

    Assessing the efficiency of maintenance operators: a case study of turning railway wheelsets on an under-floor wheel lathe

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    The present paper assesses the technical efficiency of different operators turning railway wheelsets on a under-floor wheel lathe. This type of lathe is a Computer Numerical Control (CNC) machine used to turn wheelsets in-situ on the train. As railway wheels are turned, a certain amount of the wheel diameter is lost to restore the tread profile and full flange thickness of the wheel. The technical efficiencies of the different wheel lathe operators are assessed using a Stochastic Frontier Analysis (SFA), whilst controlling for other explaining variables such as the flange thickness and the occurrence of rolling contact fatigue (RCF) defects, wheel flats and cavities. Different model specifications for the SFA are compared with Linear Mixed Model (LMM) specifications, showing that the SFA model exhibits a better Akaike Information Criterion (AIC)

    The CEDAR Project

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    The LHC project at CERN requires both the handling of a huge amount of engineering information and the control of the coherence of this information as the design work evolves on the machine and the experiments. A commercial Engineering Data Management System, (EDMS), is being implemented to manage data for the design, construction, installation and maintenance of both the accelerator and the experiments. This CERN-wide project is called CEDAR The World Wide Web is used to make the information accessible at CERN and in the external collaborating laboratories around the world. In this paper we describe the objectives of the CEDAR project, the different subprojects in the machine and the experiments as well as the first results of the implementation work

    Steps to improve gender diversity in the fields of coastal geosciences and engineering

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    Robust data are the base of effective gender diversity policy. Evidence shows that gender inequality is still pervasive in science, technology, engineering and mathematics (STEM). Coastal geoscience and engineering (CGE) encompasses professionals working on coastal processes, integrating expertise across physics, geomorphology, engineering, planning and management. The article presents novel results of gender inequality and experiences of gender bias in CGE, and proposes practical steps to address it. It analyses the gender representation in 9 societies, 25 journals, and 10 conferences in CGE and establishes that women represent 30% of the international CGE community, yet there is under-representation in prestige roles such as journal editorial board members (15% women) and conference organisers (18% women). The data show that female underrepresentation is less prominent when the path to prestige roles is clearly outlined and candidates can self-nominate or volunteer instead of the traditional invitation-only pathway. By analysing the views of 314 survey respondents (34% male, 65% female, and 1% ‘‘other’’), we show that 81% perceive the lack of female role models as a key hurdle for gender equity, and a significantly larger proportion of females (47%) felt held back in their careers due to their gender in comparison with males (9%). The lack of women in prestige roles and senior positions contributes to 81% of survey respondents perceiving the lack of female role models in CGE as a key hurdle for gender equality. While it is clear that having more women as role models is important, this is not enough to effect change. Here seven practical steps towards achieving gender equity in CGE are presented: (1) Advocate for more women in prestige roles; (2) Promote high-achieving females; (3) Create awareness of gender bias; (4) Speak up; (5) Get better support for return to work; (6) Redefine success; and, (7) Encourage more women to enter the discipline at a young age. Some of these steps can be successfully implemented immediately (steps 1–4), while others need institutional engagement and represent major societal overhauls. In any case, these seven practical steps require actions that can start immediately

    The academy for future science faculty:randomized controlled trial of theory-driven coaching to shape development and diversity of early-career scientists

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    Background: Approaches to training biomedical scientists have created a talented research community. However, they have failed to create a professional workforce that includes many racial and ethnic minorities and women in proportion to their representation in the population or in PhD training. This is particularly true at the faculty level. Explanations for the absence of diversity in faculty ranks can be found in social science theories that reveal processes by which individuals develop identities, experiences, and skills required to be seen as legitimate within the profession. Methods/Design: Using the social science theories of Communities of Practice, Social Cognitive Career Theory, identity formation, and cultural capital, we have developed and are testing a novel coaching-based model to address some of the limitations of previous diversity approaches. This coaching intervention (The Academy for Future Science Faculty) includes annual in-person meetings of students and trained faculty Career Coaches, along with ongoing virtual coaching, group meetings and communication. The model is being tested as a randomized controlled trial with two cohorts of biomedical PhD students from across the U.S., one recruited at the start of their PhDs and one nearing completion. Stratification into the experimental and control groups, and to coaching groups within the experimental arms, achieved equal numbers of students by race, ethnicity and gender to the extent possible. A fundamental design element of the Academy is to teach and make visible the social science principles which highly influence scientific advancement, as well as acknowledging the extra challenges faced by underrepresented groups working to be seen as legitimate within the scientific communities. Discussion: The strategy being tested is based upon a novel application of the well-established principles of deploying highly skilled coaches, selected and trained for their ability to develop talents of others. This coaching model is intended to be a complement, rather than a substitute, for traditional mentoring in biomedical research training, and is being tested as such

    Once the shovel hits the ground : Evaluating the management of complex implementation processes of public-private partnership infrastructure projects with qualitative comparative analysis

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    Much attention is being paid to the planning of public-private partnership (PPP) infrastructure projects. The subsequent implementation phase – when the contract has been signed and the project ‘starts rolling’ – has received less attention. However, sound agreements and good intentions in project planning can easily fail in project implementation. Implementing PPP infrastructure projects is complex, but what does this complexity entail? How are projects managed, and how do public and private partners cooperate in implementation? What are effective management strategies to achieve satisfactory outcomes? This is the fi rst set of questions addressed in this thesis. Importantly, the complexity of PPP infrastructure development imposes requirements on the evaluation methods that can be applied for studying these questions. Evaluation methods that ignore complexity do not create a realistic understanding of PPP implementation processes, with the consequence that evaluations tell us little about what works and what does not, in which contexts, and why. This hampers learning from evaluations. What are the requirements for a complexity-informed evaluation method? And how does qualitative comparative analysis (QCA) meet these requirements? This is the second set of questions addressed in this thesis

    Light rail transit cost performance: Opportunities for future-proofing

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    © 2017 Elsevier Ltd The cost performance of Light Rail Transit (LRT) systems have been scrutinized by the popular press and public sector infrastructure agencies as they have been prone to incurring cost increases in their capital expenditures (CAPEX). In tackling such increases, emphasis is placed on mitigating strategic misrepresentation and optimism bias, which has hindered the public sectors ability to embrace innovation, particularly with regard to the justification and adoption of LRT. More often than not, operational expenditure (OPEX) is neglected, and is not considered a part of the transportation cost performance literature. The aim of this paper is to examine the equivocality that surrounds the determination of cost performance of LRT projects. It is suggested that the public sector should move beyond focusing on strategic misrepresentation and optimism bias, as many governments worldwide now have in place mechanisms to address such issues, and instead focus on future-proofing their assets. It is suggested that the key enablers of future-proofing LRT are (1) private finance; (2) delivery strategy (e.g. design-build-finance-operate); (3) digitization (e.g. building information modelling); and (4) asset management (e.g. smart technologies). If the public sector is to provide an LRT system that is cost effective and able to respond to the demands imposed by climate change, then it needs to be considered from a life-cycle perspective and funding sought from the private sector to ensure its viability

    Effect of Genomic and Amino Acid Sequence Mutation on Virulence and Therapeutic Target of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS COV-2)

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    Endriyas Kelta Wabalo, Abebe Dukessa Dubiwak, Mengistu Welde Senbetu, Tariku Sime Gizaw Department of Biomedical Sciences, Faculty of Medical Sciences, Institute of Health, Jimma University, Jimma, EthiopiaCorrespondence: Endriyas Kelta WabaloDepartment of Biomedical Sciences, Faculty of Medical Sciences, Institute of Health, Jimma University, Jimma, EthiopiaEmail [email protected]: The COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It is one of the RNA coronaviruses which share the highest mutation rates of RNA viruses when compared with that of their hosts. The collective mutation rate of RNA viruses is up to a million times higher than their hosts and is correlated with enhanced virulence of viruses. The RNA, genomic material of SARS-CoV-2, has the capacity of showing amplified fast changes as the infection spreads. These changes were frequently observed in genes for spike glycoprotein, nucleocapsid, ORF1ab, and ORF8, together with RNA dependent RNA polymerase. In contrast, genes for envelope, membrane, ORF6, ORF7a and ORF7b showed no observable changes in terms of amino acid substitutions. Mutated SARS COV-2 at these particular sites has been associated with viral infectivity, false laboratory results and viral genome mutation and interferes with therapeutic targets. Interferences with therapeutic targets is frequently observed in genes for RdRp. Additionally, mutated viral genes for RdRp render slow fidelity of RdRp protein, resulting in a high mutation rate. Such a high mutation rate might allow new virulent forms of the virus to emerge and influence the disease profile. This review aimed to elaborate on the effect of genomic and amino acid sequence mutations on the virulence and therapeutic targets of SARS COV-2. To achieve this objective, multiple literatures have been reviewed.Keywords: genomic mutations, amino acid sequence mutations, virulence, therapeutic target, RdRp, SARS COV-2, spike protein
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