81,298 research outputs found
On green routing and scheduling problem
The vehicle routing and scheduling problem has been studied with much
interest within the last four decades. In this paper, some of the existing
literature dealing with routing and scheduling problems with environmental
issues is reviewed, and a description is provided of the problems that have
been investigated and how they are treated using combinatorial optimization
tools
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Current practice and challenges towards handling uncertainty for effective outcomes in maintenance
The combination of viable heuristic attributes with statistical measurements presents significant challenges in industrial maintenance for complex assets under through-life service contracts. Techniques to obtain and process heuristic attributes raise numerous uncertainties which often go undefined and unmitigated. A holistic view of these uncertainties may improve decision-making capabilities and reduce maintenance costs and turnaround time. It is therefore necessary to identify and rank factors that influence uncertainties originating from challenges in the above context. This, along with an identification of who contributes to such challenges and current practice to handle them, sets the focus for this study.
The influence of 32 categorised factors on uncertainty is assessed through a questionnaire completed by nine experienced maintenance managers from a leading defence company. The pedigree approach is applied to score validity of respondentsâ answers according to their experience and job role to normalise scores. Results are discussed in interviews with respondents along with current practice in and ways to improve uncertainty assessment. Scores are weighted through the Analytical Hierarchy Process (AHP) in order to identify the most influential factors on uncertainty in maintenance. The analysis revealed that these include: intellectual property rights (IPR), maintainer performance, quality of information, resistance to change, stakeholder communication and technology integration. These are verified with 40 practitioners from various industrial backgrounds. From the interviews, it is deemed that a holistic view of heuristic and statistical attributes ultimately allows for more accomplished decision-making but requires trade-offs between quality and cost over the assetâs life cycle
Exact Inference Techniques for the Analysis of Bayesian Attack Graphs
Attack graphs are a powerful tool for security risk assessment by analysing
network vulnerabilities and the paths attackers can use to compromise network
resources. The uncertainty about the attacker's behaviour makes Bayesian
networks suitable to model attack graphs to perform static and dynamic
analysis. Previous approaches have focused on the formalization of attack
graphs into a Bayesian model rather than proposing mechanisms for their
analysis. In this paper we propose to use efficient algorithms to make exact
inference in Bayesian attack graphs, enabling the static and dynamic network
risk assessments. To support the validity of our approach we have performed an
extensive experimental evaluation on synthetic Bayesian attack graphs with
different topologies, showing the computational advantages in terms of time and
memory use of the proposed techniques when compared to existing approaches.Comment: 14 pages, 15 figure
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Moral imagination or heuristic toolbox? Events and the risk assessment of structured financial products in the financial bubble
The paper uses the example of the failure of bankers and financial managers to understand the risks of dealing in structured financial products, prior to the financial collapse, to investigate how people respond to crises. It focuses on whether crises cause people to challenge their habitual frames by the application of moral imagination. It is proposed that the structure of financial products and their markets triggered the use of heuristics that contributed to the underestimation of risks. It is further proposed that such framing heuristics are highly specialised to specific contexts, and are part of a wider set of heuristics that people carry in their cognitive âadaptive tool boxesâ. Consequently, it is argued, when a crisis occurs the heuristics are not challenged, but are simply put away, and other more appropriate heuristics put to use until a sense of normality returns, and the use of the old heuristics is resumed
Effects of user experience on user resistance to change to the voice user interface of an inâvehicle infotainment system: Implications for platform and standards competition
This study examines the effects of user experience on user resistance to changeâparticularly, on the relationship between user resistance to change and its antecedents (i.e. switching costs and perceived value) in the context of the voice user interface of an in-vehicle infotainment (IVI) system. This research offers several salient findings. First, it shows that user experience positively moderates the relationship between uncertainty costs (one type of switching cost) and user resistance. It also negatively moderates the association between perceived value and user resistance. Second, the research test results demonstrate that users with a high degree of prior experience with the voice user interface of other smart devices exhibit low user resistance to change to the voice user interface in an IVI system. Third, we show that three types of switching costs (transition costs, in particular) may directly influence users to resist a change to the voice user interface. Fourth, our test results empirically demonstrate that both switching costs and perceived value affect user resistance to change in the context of an IVI system, which differs from the traditional IS research setting (i.e. enterprise systems). These findings may guide not only platform leaders in designing user interfaces, user experiences, and marketing strategies, but also firms that want to defend themselves from platform envelopment while devising defensive strategies in platform and standards competition
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