The purpose of this work is to evaluate the performance of an optimization algorithm from the field of evolutionary computation, namely an Evolution Strategy, in back analysis of geomechanical parameters in underground structures. This analysis was carried out through a parametric study of a synthetic case of a tunnel construction. Different combinations of parameters and measurements were carried out to test the performance of the algorithm. In order to have a comparison base for its performance also three classical optimization algorithms based on the gradient of the error function and a Genetic Algorithm were used. It was concluded that the Evolution Strategy algorithm presents interesting capabilities in terms of robustness and efficiency allowing the mitigation of some of the limitations of the classical algorithms.Moreover a back analysis study of geomechanical parameters using real monitoring data and a 3D numerical model of a hydraulic underground structure being built in the North of Portugal was performed using the Evolution Strategy algorithm, in order to reduce the uncertainties about the parameters evaluated by in situ and laboratory tests. It was verified that the low quantity of monitoring data available hinders the possibility to identify the parameters of interest. The existence of information of only one additional extensometer perpendicular to the existing one would allow this identification to succeed.
Objectives: This study aimed to assess the relationship between sociodemographic, clinical, and psychological variables with quality of life (QoL) and the moderating role of caregivers' age and caregiving duration in caregivers of patients with Multiple Myeloma. Method: The sample included 118 caregivers who completed questionnaires that assessed psychological morbidity, satisfaction with social support, coping, burden, unmet needs, and QoL. Results: High psychological morbidity, burden and information, financial and emotional unmet needs were associated with lower QoL, while higher satisfaction with social support and more effective use of coping strategies were associated with better QoL. Women caregivers reported more satisfaction with social support and those who did not choose to care reported greater financial unmet needs and more use of coping strategies. The relationship between caregivers' psychological morbidity/social support and QoL was mediated by emotional needs and double mediated by coping and burden. The caregivers' age moderated the relationship between psychological morbidity/social support and emotional needs. Conclusion: Interventions to support the caregiver's emotional needs to promote their QoL are needed. These should be particularly tailored for older caregivers reporting greater psychological morbidity and younger caregivers less satisfied with their social support, as they have a negative indirect impact on their QoL.
Modelling a rock mass in an accurate and realistic way allows researchers to reduce the uncertainty associated with its characterisation and reproduce the intrinsic spatial variability and heterogeneities present in the rock mass. However, there is often a lack of a structured methodology to characterise heterogeneous rock masses using geotechnical information available from the prospection phase. This paper presents a characterization methodology based on the geostatistical simulation of geotechnical variables and the application of a scenario reduction technique aimed at selecting a reduced number of realisations able to statistically represent a large set of realisations obtained by the geostatistical approach. This type of information is useful for a further rock mass behaviour analysis. The methodology is applied to a gold deposit with the goal of understanding its main differences to traditional approaches based on a deterministic modelling of the rock mass. The obtained results show the suitability of the methodology to characterise heterogeneous rock masses, since there were considerable differences between the results of the proposed methodology, mainly concerning the theoretical tunnel displacements, and the ones obtained with a traditional approach.
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