1,720,952 research outputs found
A Risk Analysis for Asset Management Considering Climate Change
No full textAbstractThis paper presents an optimization framework for highway infrastructure elements that integrates risk profiles (for infrastructures) and economic aspects. One main goal is to assess the necessary additional effort to satisfy performance constraints under different scenarios of climate change. In order to be easily deployable by national road administrations (NRAs), this framework is built in such a way that it can be embedded into asset management systems that include an inventory of the asset, inspection strategies (to report element conditions and safety defects) and decision-making for funds allocation. Using the inventory of the asset and condition assessment as input, the method aims to determine some degradation profiles for bridge components, retaining walls and steep embankments. The method to determine the degradation process is detailed so that any infrastructure manager can determine their own deterioration processes based on the inventory and condition assessment of their stock. Combining degradation of highway infrastructures with a risk analysis, this paper presents an optimization framework to determine optimal management strategies
Safety Management and Risk Modelling in Aviation: The challenge of quantifying management influences
No full textAviation accidents result from a combination of many different causal factors ( human errors, technical failures, environmental and organisational influences). Increasing interest over the past two decades in causal modelling of organisational factors has been motivated by the desire to understand these fundamental causes and their influences in risk. Although there is a need for system-wide accident models in air transport, such models are currently lacking. Causal Modelling of Air Transportation System (CATS) was one of the first projects to develop such a model in aviation. Based on the experience of CATS, this PhD research examines the place and role of the human and management models and their quantification in aviation. This study reveals several challenges in respect to safety management modelling, including availability of data, and techniques for the management quantification. New insights found in this research were taken on board to develop a generic hierarchical control model for aviation safety and a list of human and technical factors to be treated in risk modelling in aviation. A new way of quantifying safety management in risk model is also proposed. Several recommendations were made for an extension of risk modelling in CATS, or in the other research with similar research objectives.Ssafety Science GroupTechnology, Policy and Managemen
Modelling human and organizational behaviour in a high-risk operation
No full textA core part of the risk modelling program for the Oil and Gas industry being carried out at Delft University of Technology is the influence of humans, within an organisation, as well as the technical factors. Specific attention is given to the incentive structure of operators, staff and managers, which in previous models had only been indicated more generally by motivation and conflict resolution. An incentive structure represents an empirical framework for an organisation which characterises the relationship between specific behaviours of employees and the probabilities of receiving various incentives. Most of the scientific literature on incentives is about the formal incentive structure that companies have in place. There are however, many more incentives so that a decision to choose one from several possible courses of action and decide to commit to safety above other personal and organizational goals is certainly influenced by personal safety attitudes, but there are also strong organizational aspects to these influences. Management influences and management actions are considered important in this respect because their actions influence personal safety attitudes to some degree. For instance, personal “need” and “incentives” are factors / motivations that can be coupled with a company’s goals influenced by management influences. Employees who feel they have access to good career development opportunities, or who are praised by managers for doing a good job, are more motivated and more likely to committed to their work. Lin (2008, 2011) studied quantifying the influences of management actions on human performance, expressed through the quality and operation of the management actions. Interviews with personnel serve to uncover which signals are sent by managers and colleagues and how they are received. This paper discusses the different incentive structures identified and describes methods used to uncover and quantify them in a wider risk model.Values and TechnologyTechnology, Policy and Managemen
Modelling risk in high hazard operations: Integrating technical, organisational and cultural factors
No full textRecent disasters in high hazard industries such as Oil and Gas Exploration (The Deepwater Horizon) and Petrochemical production (Texas City) have been found to have causes that range from direct technical failures through organizational shortcomings right up to weak regulation and inappropriate company cultures. Risk models have generally concentrated upon technical failures, which are easier to construct and for which there is more concrete data. The primary causes, as identified by the US Chemical Safety Board for Texas City and the Presidential Commission for the Deepwater Horizon, lie firmly rooted in the culture of the organization and determine the way in which individuals go about risky activities. Modelling human activities, especially collectively rather than individual human errors as is done in most human models, is a quite different proposition, in which complex interactions between different individuals and levels change over time as success and failure alter the pattern of payoffs. This paper examines the development of an integrated model for risk in a real-time environment for the hydrocarbon industry. It is based originally on the CATS model for commercial aviation safety, that first attempted to address some of these problems in a relatively simple way. Aviation is, however, a relatively simple activity, with large numbers of common components in a constrained environment. The Oil and Gas industry is significantly more diverse, covering the gamut from exploration, drilling, production, transport, refining and chemical production, each with its own potential for large scale disaster, but in the case of an integrated oil company all run by individuals within a common company culture. Other papers will cover the details of specific issues; this paper covers the integration of the model as a whole.Values and TechnologyTechnology, Policy and Managemen
Modeling contractor and company employee behavior in high hazard operation
Full text linkThe recent blow-out and subsequent environmental disaster in the Gulf of Mexico have highlighted a number of serious problems in scientific thinking about safety. Risk models have generally concentrated on technical failures, which are easier to model and for which there are more concrete data. However, many primary cause of the disasters, such as BP’s Texas City and Deepwater Horizon, are rooted in management decisions and organizational. Therefore, there is a strong need to develop a risk management support tool for chemical process industries which incorporates human and organizational factors into quantified risk models. In this paper, we model two human performance model for oil and gas company Royal Dutch Shell. Interviews were conducted to obtain important human factors. As the quality and operation of the management actions have important influences on human factors (e.g. safety attitude, training), we have linked a safety management model with the human factors model and quantify the risk implications of different management changes to prevent accidents. The methodology of integrating organisational factors into a Bayesian Belief Networks (BBNs) model is discussed in Lin et al. (2012). In this paper the development and quantification of human and management factors for an international oil company is given.Values and TechnologyTechnology, Policy and Managemen
Automatic texture segmentation for content-based image retrieval application
Full text linkIn this article, a brief review on texture segmentation is presented, before a novel automatic texture segmentation algorithm is developed. The algorithm is based on a modified discrete wavelet frames and the mean shift algorithm. The proposed technique is tested on a range of textured images including composite texture images, synthetic texture images, real scene images as well as our main source of images, the museum images of various kinds. An extension to the automatic texture segmentation, a texture identifier is also introduced for integration into a retrieval system, providing an excellent approach to content-based image retrieval using texture features
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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