Decision support in short term and long term maintenance planning using condition monitoring information

Author(s):  
T.M. Andersen
Author(s):  
Jose´ G. Rangel-Rami´rez ◽  
John D. So̸rensen

Deterioration processes such as fatigue and corrosion are typically affecting offshore structures. To “control” this deterioration, inspection and maintenance activities are developed. Probabilistic methodologies represent an important tool to identify the suitable strategy to inspect and control the deterioration in structures such as offshore wind turbines (OWT). Besides these methods, the integration of condition monitoring information (CMI) can optimize the mitigation activities as an updating tool. In this paper, a framework for risk-based inspection and maintenance planning (RBI) is applied for OWT incorporating CMI, addressing this analysis to fatigue prone details in welded steel joints at jacket or tripod steel support structures for offshore wind turbines. The increase of turbulence in wind farms is taken into account by using a code-based turbulence model. Further, additional modes t integrate CMI in the RBI approach for optimal planning of inspection and maintenance. As part of the results, the life cycle reliabilities and inspection times are calculated, showing that earlier inspections are needed at in-wind farm sites. This is expected due to the wake turbulence increasing the wind load. With the integration of CMI by means Bayesian inference, a slightly change of first inspection times are coming up, influenced by the reduction of the uncertainty and harsher or milder external agents.


2021 ◽  
Vol 1 ◽  
Author(s):  
Isni Septima Anindhita

The Ministry of Public Works and Public Housing (PUPR) has the duty and responsibility to carry out effective and efficient river operation activities and river infrastructure including overcoming floods during the rainy season, but these activities are deemed necessary for improvement in planning procedures. To realize this goal, it is necessary to manage risks that can reduce river performance and river infrastructure as flood control. With risk management in this activity, it is possible to apply the sequence of risks that occur which are then used as recommendations for action (risk response) and risk-based development strategies to improve river performance and river infrastructure to control floods through operation and maintenance activities to build a functional and sustainable system. Suitable for long-term planning and short-term maintenance needs.


1993 ◽  
Vol 23 (6) ◽  
pp. 1078-1095 ◽  
Author(s):  
Robert G. Davis ◽  
David L. Martell

This paper describes a decision support system that forest managers can use to help evaluate short-term, site-specific silvicultural operating plans in terms of their potential impact on long-term, forest-level strategic objectives. The system is based upon strategic and tactical forest-level silvicultural planning models that are linked with each other and with a geographical information system. Managers can first use the strategic mathematical programming model to develop broad silvicultural strategies based on aggregate timber strata. These strategies help them to subjectively delineate specific candidate sites that might be treated during the first 10 years of a much longer planning horizon using a geographical information system and to describe potential silvicultural prescriptions for each candidate site. The tactical model identifies an annual silvicultural schedule for these candidate sites in the first 10 years, and a harvesting and regeneration schedule by 10-year periods for aggregate timber strata for the remainder of the planning horizon, that will maximize the sustainable yield of one or more timber species in the whole forest, given the candidate sites and treatments specified by the managers. The system is demonstrated on a 90 000 - ha area in northeastern Ontario.


2019 ◽  
Vol 30 (5) ◽  
pp. 2997-3014 ◽  
Author(s):  
Benjamin Kowialiewski ◽  
Laurens Van Calster ◽  
Lucie Attout ◽  
Christophe Phillips ◽  
Steve Majerus

Abstract An influential theoretical account of working memory (WM) considers that WM is based on direct activation of long-term memory knowledge. While there is empirical support for this position in the visual WM domain, direct evidence is scarce in the verbal WM domain. This question is critical for models of verbal WM, as the question of whether short-term maintenance of verbal information relies on direct activation within the long-term linguistic knowledge base or not is still debated. In this study, we examined the extent to which short-term maintenance of lexico-semantic knowledge relies on neural activation patterns in linguistic cortices, and this by using a fast encoding running span task for word and nonword stimuli minimizing strategic encoding mechanisms. Multivariate analyses showed specific neural patterns for the encoding and maintenance of word versus nonword stimuli. These patterns were not detectable anymore when participants were instructed to stop maintaining the memoranda. The patterns involved specific regions within the dorsal and ventral pathways, which are considered to support phonological and semantic processing to various degrees. This study provides novel evidence for a role of linguistic cortices in the representation of long-term memory linguistic knowledge during WM processing.


2008 ◽  
Vol 82 (6) ◽  
pp. 3135-3138 ◽  
Author(s):  
Sarah E. Blutt ◽  
Kelly L. Warfield ◽  
Mary K. Estes ◽  
Margaret E. Conner

ABSTRACT Correlates of protection from rotavirus infection are controversial. We compared the roles of B and T lymphocytes in protective immunity induced either by intranasally administered nonreplicating viruslike particles or inactivated virus or by orally administered murine rotavirus. We found that protection induced by nonreplicating vaccines requires CD4+ T cells and CD40/CD40L. In contrast, T cells were not required for short-term protective immunity induced by infection, but both T-cell-dependent and -independent mechanisms contributed to long-term maintenance of protection. Our findings indicate that more than one marker of protective immunity exists and that these markers depend on the vaccine that is administered.


2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 505-505
Author(s):  
Brian Christopher Baumann ◽  
Wei-Ting Hwang ◽  
Sharadha Srinivasan ◽  
Xingmei Wang ◽  
Ronac Mamtani ◽  
...  

505 Background: Patients with high-risk muscle-invasive bladder cancer (MIBC) who are borderline medically operable for radical cystectomy (RC) face a difficult decision between RC which has higher short-term treatment-related morbidity/mortality & chemoradiotherapy (CRT) which is better tolerated in the short-term but may have worse long-term cancer control outcomes. There are no existing decision support tools to assist patients & providers in understanding these trade-offs. Herein, we developed a visualization tool to inform patients & providers how the relative risks & benefits of RC & CRT vary over time with respect to overall survival (OS). Methods: We identified cT2-3 N0 M0 urothelial bladder cancer patients ≥65 y/o treated with RC +/- chemo (n = 5981) or definitive-dose CRT after TURBT (n = 793) in the National Cancer Database, 2003-2011. The database was split into a development & validation cohort. Multivariate Cox regression with time-varying hazard ratio was performed to assess pre-treatment factors associated with OS. The inverse probability of treatment weighting method using the propensity score was employed to reduce selection bias. External validation was performed. Visualization tool showing adjusted survival curves based on pre-op patient features was generated with input from patients & a multidisciplinary expert panel. Tool calculates median OS & the “break-even point,” where the short-term OS disadvantage of RC equals the long-term advantage of RC (i.e. the point where the restricted mean survival for RC & CRT are equal). Results: On MVA, significant predictors of OS were age, Charlson Deyo comorbidity index, & cT stage (p < 0.001 for all). Using these results, we iteratively developed a web application that utilizes clinical inputs to generate patient-specific survival curves that display estimated OS differences over time. Median OS, the break-even point, & percent alive at the break-even point are provided. Conclusions: This is the first decision-support tool developed to assist high-risk borderline operable MIBC patients & their providers in understanding the short-term & long-term trade-offs between RC & CRT. Additional testing is underway.


2014 ◽  
Vol 718 ◽  
pp. 105-109
Author(s):  
Eva Oravcová ◽  
Miroslav Zelko

Comprehensive environmental observation, eco-innovation and smartization are essential to ensure the delivery of the long-term data and information required to address the shift towards smart, green and integrated raw materials efficiency. For this reason we need the mine-wide digitalization and informatization base model, an advanced mine-wide decision support system and a smart supervision system to supervise and control the production, back to predefined short-term production targets with most likelihood and optimal approaches. There are three main steps to be taken: analysis, evaluation and determination of the shift requirements, development of the models as well as modeling of the scenarios and connection to the smart platform for the support of the decision makers. The paper aims to consider what would be required for a raw materials area to operate as a modern smart technology-supported business. It attempts to provide a vision of some future smart architectures scenarios.


2020 ◽  
Vol 4 (23) ◽  
pp. 5951-5957
Author(s):  
Alden A. Moccia ◽  
Christian Taverna ◽  
Sämi Schär ◽  
Anna Vanazzi ◽  
Stéphanie Rondeau ◽  
...  

Abstract The Swiss Group for Clinical Cancer Research (SAKK) conducted the SAKK 35/03 randomized trial (NCT00227695) to investigate different rituximab monotherapy schedules in patients with follicular lymphoma (FL). Here, we report their long-term treatment outcome. Two-hundred and seventy FL patients were treated with 4 weekly doses of rituximab monotherapy (375 mg/m2); 165 of them, achieving at least a partial response, were randomly assigned to maintenance rituximab (375 mg/m2 every 2 months) on a short-term (4 administrations; n = 82) or a long-term (up to a maximum of 5 years; n = 83) schedule. The primary end point was event-free survival (EFS). At a median follow-up period of 10 years, median EFS was 3.4 years (95% confidence interval [CI], 2.1-5.5) in the short-term arm and 5.3 years (95% CI, 3.5-7.5) in the long-term arm. Using the prespecified log-rank test, this difference is not statistically significant (P = .39). There also was not a statistically significant difference in progression-free survival or overall survival (OS). Median OS was 11.0 years (95% CI, 11.0-NA) in the short-term arm and was not reached in the long-term arm (P = .80). The incidence of second cancers was similar in the 2 arms (9 patients after short-term maintenance and 10 patients after long-term maintenance). No major late toxicities emerged. No significant benefit of prolonged maintenance became evident with longer follow-up. Notably, in symptomatic patients in need of immediate treatment, the 10-year OS rate was 83% (95% CI, 73-89%). These findings indicate that single-agent rituximab may be a valid first-line option for symptomatic patients with advanced FL.


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