Repair Maintenance Research Articles

Nr5a2 is dispensable for zygotic genome activation but essential for morula development.

Early embryogenesis is driven by transcription factors (TFs) that first activate the zygotic genome and then specify the lineages constituting the blastocyst. Although the TFs specifying the blastocyst's lineages are well characterized, those playing earlier roles remain poorly defined. Using mouse models of the TF Nr5a2, we show that Nr5a2-/- embryos arrest at the early morula stage and exhibit altered lineage specification, frequent mitotic failure, and substantial chromosome segregation defects. Although NR5A2 plays a minor but measurable role during zygotic genome activation, it predominantly acts as a master regulator at the eight-cell stage, controlling expression of lineage-specifying TFs and genes involved in mitosis, telomere maintenance, and DNA repair. We conclude that NR5A2 coordinates proliferation, genome stability, and lineage specification to ensure correct morula development.

The ‘hangar of the future’ for sustainable aviation

AbstractSustainability is becoming a major strategic driver within the aviation industry, which has moved from providing primarily economic benefits to delivering the ‘triple bottom line’, including social and environmental impact as well as financial performance. Sustainable aviation is also being tracked by the International Civil Aviation Organisation (ICAO) Global Collation for Sustainable Aviation. Operations and Infrastructure is an important near-term opportunity to deliver sustainability benefits. Digital Technologies, Integrated Vehicle Health Management (IVHM) and Maintenance Repair and Overhaul (MRO) play a prominent role in implementing these benefits, with a particular focus on operational efficiencies. As part of this, the sustainable smart hangar of the future is a concept that is becoming more and more important in forming the future of the aviation industry. The Hangar of the Future is an excellent opportunity for innovation, combining the progress in manufacturing, materials, robotics and artificial intelligence technologies. Succeeding in developing a hangar with these characteristics will provide us with potential benefits ranging from reduced downtime and costs to improved safety and environmental impact. This work explores some of the key features related to the sustainable smart hangar of the future by discussing research that takes place in DARTeC’s (Digital Aviation Research and Technology Centre) hangar led by the IVHM Centre in Cranfield. Additionally, the paper touches on some longer-term aspirations.

Grouping-maintenance of multi-components production system under ecological background

Purpose: The purpose of this paper is to propose an opportunistic group maintenance model for a multi-component series system considering reducing CO2 emission and increasing system efficiency, which establishes a maintenance policy to minimize the cost rate of the system life cycle.Design/methodology/approach: Structural dependence and economic dependence between the components in a multi-component series system are analyzed to make a condition-based maintenance policy. To minimize the cost rate of the system life cycle, clustering theory and two decision variables, which include the preventative maintenance cycle multiplier and basic preventive maintenance interval of each component, is utilized to make an opportunistic policy for system optimal maintenance under the background of increasing energy efficiency and reducing CO2 emissions.Findings: It can be concluded that the government imposes fines on excessive CO2 emissions and energy consumption indicators, which can influence the maintenance decisions of enterprises, promote enterprises to shorten the cycle of preventive maintenance, and avoid excessive CO2 emissions of various components and exceed the indicators as much as possible, so as to enable enterprises to actively save energy, reduce emissions and control carbon emissions. Furthermore, when the single preparation cost of repair maintenance increases, enterprises need to shorten the maintenance period to avoid frequent component failures. As the cost of a single prep for preventive maintenance rises, organizations need to extend maintenance cycles and avoid frequent parts downtime - minimizing their own repair costs.Practical implications: Considering the high maintenance cost and low energy efficiency of multi-component systems, this model assists production managers to have better maintenance of these systems.Originality/value: 1.Model innovation: comprehensive consideration of two variables in the selection of decision variables for preventive maintenance or opportunistic maintenance; The selection and synthesis of ecological factors when making ecologically conscious maintenance decisions for multi-component systems make up for the gaps of single variables and one-sided indicators in previous studies and models. 2. Methodological innovation: In the identification of opportunity maintenance, the idea of clustering is first combined; In the simulation analysis, genetic algorithm is used to obtain the optimal parameters quickly and accurately. A blend of management, statistics, biology and computer science.

Mechanism of BCDX2-mediated RAD51 nucleation on short ssDNA stretches and fork DNA.

Homologous recombination (HR) factors are crucial for DSB repair and processing stalled replication forks. RAD51 paralogs, including RAD51B, RAD51C, RAD51D, XRCC2 and XRCC3, have emerged as essential tumour suppressors, forming two subcomplexes, BCDX2 and CX3. Mutations in these genes are associated with cancer susceptibility and Fanconi anaemia, yet their biochemical activities remain unclear. This study reveals a linear arrangement of BCDX2 subunits compared to the RAD51 ring. BCDX2 shows a strong affinity towards single-stranded DNA (ssDNA) via unique binding mechanism compared to RAD51, and a contribution of DX2 subunits in binding branched DNA substrates. We demonstrate that BCDX2 facilitates RAD51 loading on ssDNA by suppressing the cooperative requirement of RAD51 binding to DNA and stabilizing the filament. Notably, BCDX2 also promotes RAD51 loading on short ssDNA and reversed replication fork substrates. Moreover, while mutants defective in ssDNA binding retain the ability to bind branched DNA substrates, they still facilitate RAD51 loading onto reversed replication forks. Our study provides mechanistic insights into how the BCDX2 complex stimulates the formation of BRCA2-independent RAD51 filaments on short stretches of ssDNA present at ssDNA gaps or stalled replication forks, highlighting its role in genome maintenance and DNA repair.

Telomere biology and its maintenance in schizophrenia spectrum disorders: Exploring links to cognition

ObjectiveContemporary research suggests reduced telomere length in schizophrenia spectrum disorders (SZ) compared to age-adjusted non-affected individuals. However, the role of telomere maintenance and telomere repair in SZ is poorly understood as well as the involvement of telomere biology in cognitive abnormalities in SZ. MethodsThe study consisted of 758 participants (SZ [n = 357] and healthy controls, HC [n = 401]) collected as part of the Norwegian TOP study. Participants were assessed with standardized neuropsychological tests measuring five cognitive domains. Leucocyte telomere length (TL) was measured via blood and determined by quantitative real-time Polymerase Chain Reaction (qPCR) providing a telomere to single copy ratio (T/S ratio), used to estimate the mean telomere length. Telomerase activity was assessed by the expression levels of the Telomerase Reverse Transcriptase (TERT) and Telomerase RNA Component (TERC) genes. To assess telomere maintenance and telomere repair we calculated the telomerase expression to TL ratio (TERT/TL and TERC/TL respectively). ResultsPatients had reduced TERT (F = 5.03, p = 0.03), but not TERC expression (F = 1.04, p = 0.31), and higher TERT/TL (F = 6.68, p = 0.01) and TERC/TL (F = 6.71, p = 0.01), adjusted for age, sex, and ethnicity. No statistically significant association was observed between any of the telomere biology markers and the cognitive domains (p > 0.05). ConclusionOur study shows changes in TERT expression and telomere maintenance and telomere repair in SZ compared HC. However, the role of telomere biology in the mechanism underlying cognitive impairment in psychosis seems limited.

Loss of Insulin Signaling in Microglia Impairs Cellular Uptake of Aβ and Neuroinflammatory Response Exacerbating Alzheimer-like Neuropathology.

Insulin receptors are present on cells throughout the body, including the brain. Dysregulation of insulin signaling in neurons and astrocytes has been implicated in altered mood, cognition, and the pathogenesis of Alzheimers disease (AD). To define the role of insulin signaling in microglia, the primary phagocytes in brain critical for maintenance and damage repair, we created mice with an inducible microglia-specific insulin receptor knockout (MG-IRKO). RiboTag profiling of microglial mRNAs revealed that loss of insulin signaling results in alterations of gene expression in pathways related to innate immunity and cellular metabolism. In vitro, loss of insulin signaling in microglia results in metabolic reprograming with an increase in glycolysis and impaired uptake of Aβ. In vivo, MG-IRKO mice exhibit alterations in mood and social behavior, and when crossed with the 5xFAD mouse model of AD, the resultant mice exhibit increased levels of Aβ; plaque and elevated neuroinflammation. Thus, insulin signaling in microglia plays a key role in microglial cellular metabolism, neuroinflammation and the ability of the cells to take up Aβ; such that reduced insulin signaling in microglia alters mood and social behavior and accelerates AD pathogenesis. Together these data indicate key roles of insulin action in microglia and the potential of targeting insulin signaling in microglia in treatment of AD.

Profit Comparison of Computer System with Hardware Redundancy Subject to Different Repair Activities

In this research paper, main concentrate of the authors on the profit comparison of computer system with hardware redundancy by introducing the concept of priority to software up-gradation, hardware preventive maintenance (PM) and hardware maximum repair time (MRT). The system fails independently from normal mode. All the repair activities such as hardware repair, software up-gradation, hardware preventive maintenance before failure and hardware replacement after maximum repair time are carried out by a single server immediately on need basis. All random variables are statistically independent. The negative exponential distribution is taken for the failure time of the component while the distributions of repair time, up-gradation time, preventive maintenance and replacement time are assumed arbitrary with different probability density functions. Semi-Markov process and regenerative point technique are used. The behaviour of profits of the system models have been examined for different parameters and costs.

Model for the Failure Prediction Mechanism of In-Service Pipelines Based on IoT Technology

With the rapid increase in pipeline mileage in China, the accurate prediction of corrosion issues in in-service pipelines has become crucial for ensuring safe pipeline operation. Traditional pipeline leakage monitoring methods are significantly limited by human factors and equipment precision, making it challenging to predict and identify leakage points accurately. Therefore, aligned with the trend of intelligent pipeline development, this study aims to construct a failure pressure prediction mechanism model for corroded pipelines based on IoT technology. This model leverages intelligent sensing and prediction to assess the safety status of corroded pipeline sections. Ultrasonic phased array technology detects specific corrosion points and detailed defect parameters within pipeline sections. The parameters are then utilized in the Simdroid domestic finite element analysis model to simulate the ultimate burst pressure of the pipeline. A single-variable approach is employed to analyze the sensitivity of different parameters to the pipeline’s ultimate burst pressure, with the minimum burst pressure point of multi-point corroded sections selected as the overall segment failure pressure. Finite element simulation data are integrated into a neural network database to predict the pipeline failure pressure. The real-time operational data of the pipeline are monitored using negative-pressure wave sensing. The operational pressure of the corroded points is compared with the algorithm-predicted failure pressure; if the values approach a critical threshold, an alarm is triggered. Moreover, the remote control terminals evaluate the pipeline’s self-rescue time, providing a buffer for pipeline leakage self-rescue. The failure prediction mechanism model for in-service pipelines was applied to the Fujian–Guangdong branch of the West–East Gas Pipeline III to verify its accuracy and feasibility. The research results offer technical support for the maintenance and emergency repair of pipeline leakage scenarios, leveraging intelligent pipeline technology to reduce costs and increase the efficiency of pipeline operations, thereby supporting the sustainable development of China’s oil and gas pipelines with theoretical and technical backing.

Quay Crane Performance Improvement and Lifecycle Extension: Retrofit Determination – A Case Study

Quay cranes (QCs) are critical equipment in Container Terminals and their performance determines the port operation efficiency in meeting operational Key Performance Indicators (KPIs). Considering 30-year lifespan of QCs and deteriorating reliability of the electrical control system, planning for timely retrofit of the QCs is critical. The paper aims to present a case study on how the performance of a batch of QCs, having more than 50% remaining lifespan, were analyzed and concluded to be retrofitted to address their deteriorating performance, high maintenance cost and obsolescence. The study methodology is based on quantitative data and employed a prospective longitudinal panel research design over sixteen years. eleven years of pre-retrofit and five years of post-retrofit operations, maintenance and financial data were collected. Convenient sampling technique was selected in this study as the QCs identified as samples were having reliability issues. The Correlation Analysis indicates strong positive correlation of more than 90% between Mean Time Between Failure, Mean Move Between Failure and Reliability KPIs. These KPIs have moderate positive correlations of about 50% with Availability KPI. These 4 KPIs have strong negative correlation of between -50% and -85% with Mean Time to Repair, Maintenance and Breakdown Repair Cost indicating performance degradation but increased maintenance and repair costs as shown by Trend Analysis. The 11-year preretrofit data has identified parameters to determine the QC retrofit prediction. The KPIs, obsolescence status, maintenance and breakdown repair cost can be used as the inputs to the future QC Retrofit Prediction Model development.

Gearbox Fault Diagnosis Method in Noisy Environments Based on Deep Residual Shrinkage Networks.

Gearbox fault diagnosis is essential in the maintenance and preventive repair of industrial systems. However, in actual working environments, noise frequently interferes with fault signals, consequently reducing the accuracy of fault diagnosis. To effectively address this issue, this paper incorporates the noise attenuation of the DRSN-CW model. A compound fault detection method for gearboxes, integrated with a cross-attention module, is proposed to enhance fault diagnosis performance in noisy environments. First, frequency domain features are extracted from the public dataset by using the fast Fourier transform (FFT). Furthermore, the cross-attention mechanism model is inserted in the optimal position to improve the extraction and recognition rate of global and local fault features. Finally, noise-related features are filtered through soft thresholds within the network structure to efficiently mitigate noise interference. The experimental results show that, compared to existing network models, the proposed model exhibits superior noise immunity and high-precision fault diagnosis performance.

Designing a collaborative maintenance planning mechanism between airline and maintenance company using a bilevel model – Considering flexible maintenance schedule and service charges

Periodic aircraft Maintenance Repair and Overhaul (MRO) activities are compulsory. To capture the features of MRO operations between airline and maintenance company under MRO outsourcing mode, we consider a collaborative aircraft maintenance planning problem, in which the airline outsources its self-operated maintenance checks to an independent maintenance company. Under such context, MRO planning conflicts between two collaborates exists especially during maintenance peak period, as airline aims to maximize flight operations revenues by receiving timely MRO service. On the other hand, maintenance company strives to accomplish heterogenous demands without causing tardiness and involving excessive MRO resources cost. Therefore, finding an effective mechanism to eliminate the conflicts between maintenance demands (from airline company) and maintenance service supply capability (from maintenance company) is indispensable for collaboration. A bi-level optimization model is formulated to describe the conflicting objectives and maintenance planning features of two independent stakeholders. To facilitates a synchronization of demand and supply and reconcile MRO conflicts, flexible maintenance schedules and service charges decisions from two independent collaborators is involved in the model, enabling a maintenance planning negotiation for finding mutual beneficial maintenance plan. An iterative algorithm deploying bounding updating strategy is developed, which generates a series of convergent-oriented bounding constraints along the iterative negotiation and guides the adjustment of maintenance demand and supply towards equilibrium. Based on the computational results in solving various maintenance planning scenarios, the impacts of different features (e.g. resource availability, resource demands level, and penalty cost of service tardiness) on airline and service company’s planning performance are analysed, revealing that maintenance service company’s own interest can be assured and maintained though it is a follower in the collaboration framework Afterwards, the managerial insights for facilitating the maintenance collaboration are further discussed.

Prospects for the houseboats and floating houses operation in Primorsky region

The article presents the results of a study the possibilities and necessary conditions for the use of houseboats and floating houses in the Primorsky region. It is shown the dynamics and general tendencies of the tourist flow in the Primorsky region over the past ten years. A brief history of floating houses appearance and respective reasons are shown. The architectural and structural types, design features, life support systems, features of their internal saturation and layout are considered. A classification of floating houses according to various criteria is proposed. Modern systems and technologies that ensure autonomy and energy independence of these objects are considered. The operation features, maintenance and periodic repair specifics of floating houses of different types during different periods of their operation are noted. The regional, natural and hydrometeorological features of the Primorsky region facilitating and complicating the use of these objects for the development of sea and island tourism are analyzed. The results of the work are part of a study aimed to the development of maritime transport technology and marine tourism, accessibility of remote areas and increasing the efficiency of the transport and logistics system of the Primorsky region taken as a whole.

SOSTDC1 Nuclear Translocation Facilitates BTIC Maintenance and CHD1-Mediated HR Repair to Promote Tumor Progression and Olaparib Resistance in TNBC.

Breast tumor-initiating cells (BTICs) of triple-negative breast cancer (TNBC) tissues actively repair DNA and are resistant to treatments including chemotherapy, radiotherapy, and targeted therapy. Herein, it is found that a previously reported secreted protein, sclerostin domain containing 1 (SOSTDC1), is abundantly expressed in BTICs of TNBC cells and positively correlated with a poor patient prognosis. SOSTDC1 knockdown impairs homologous recombination (HR) repair, BTIC maintenance, and sensitized bulk cells and BTICs to Olaparib. Mechanistically, following Olaparib treatment, SOSTDC1 translocates to the nucleus in an importin-α dependent manner. Nuclear SOSTDC1 interacts with the N-terminus of the nucleoprotein, chromatin helicase DNA-binding factor (CHD1), to promote HR repair and BTIC maintenance. Furthermore, nuclear SOSTDC1 bound to β-transducin repeat-containing protein (β-TrCP) binding motifs of CHD1 is found, thereby blocking the β-TrCP-CHD1 interaction and inhibiting β-TrCP-mediated CHD1 ubiquitination and degradation. Collectively, these findings identify a novel nuclear SOSTDC1 pathway in regulating HR repair and BTIC maintenance, providing insight into the TNBC therapeutic strategies.

Unveiling the Significance of Peroxiredoxin 6 in Central Nervous System Disorders.

Peroxiredoxin 6 (Prdx6), a unique 1-Cys member of the peroxiredoxin family, exhibits peroxidase activity, phospholipase activity, and lysophosphatidylcholine acyltransferase (LPCAT) activity. Prdx6 has been known to be an important enzyme for the maintenance of lipid peroxidation repair, cellular metabolism, inflammatory signaling, and antioxidant damage. Growing research has demonstrated that the altered activity of this enzyme is linked with various pathological processes including central nervous system (CNS) disorders. This review discusses the distinctive structure, enzyme activity, and function of Prdx6 in different CNS disorders, as well as emphasizing the significance of Prdx6 in neurological disorders.

Competitive Strategy of Chinese Maintenance Repair and Operations Industry- a Case Study of JD Industrials

As the market size of China's maintenance, repair, and operations industry continues to expand, more and more platform companies are entering this sector. In this increasingly competitive environment, having a set of market competition strategies, implementation measures, and safeguard measures tailored to the enterprise is crucial for long-term survival. This paper conducts a case study on JD Industrial, a leading B2B company in this field. This paper first analyzes the market environment of JD Industrial by using the PEST framework and puts forward the market competition strategy suitable for JD Industrial by using SWOT analysis. It also puts forward the corresponding implementation and safeguard measures for the implementation of these strategies. The potential contribution of this paper is that provide some valuable insights into JDI's market competition strategies. These insights aim to assist JDI in enhancing its market share and achieving sustainable growth in the process of competition from domestic and international rivals.

Adipose tissue reconstruction facilitated with low immunogenicity decellularized adipose tissue scaffolds.

There is currently an urgent need to develop engineered scaffolds to support new adipose tissue formation and facilitate long-term maintenance of function and defect repair to further generate prospective bioactive filler materials capable of fulfilling surgical needs. Herein, adipose regeneration methods were optimized and decellularized adipose tissue (DAT) scaffolds with good biocompatibility were fabricated. Adipose-like tissues were reconstructed using the DAT and 3T3-L1 preadipocytes, which have certain differentiation potential, and the regenerative effects of the engineered adipose tissuesin vitroandin vivowere explored. The method improved the efficiency of adipose removal from tissues, and significantly shortened the time for degreasing. Thus, the DAT not only provided a suitable space for cell growth but also promoted the proliferation, migration, and differentiation of preadipocytes within it. Following implantation of the constructed adipose tissuesin vivo, the DAT showed gradual degradation and integration with surrounding tissues, accompanied by the generation of new adipose tissue analogs. Overall, the combination of adipose-derived extracellular matrix and preadipocytes for adipose tissue reconstruction will be of benefit in the artificial construction of biomimetic implant structures for adipose tissue reconstruction, providing a practical guideline for the initial integration of adipose tissue engineering into clinical medicine.

Modeling life expectancy and cost effectiveness for UHPC bridge retrofitting techniques

Bridge components are subject to both structural loads and environmental stressors, rendering them susceptible to accelerated deterioration and potential collapse in the absence of effective maintenance and rehabilitation strategies. Moreover, the phenomenon of wet-dry cycling, coupled with elevated chloride concentrations prevalent in coastal regions, further expedites the degradation process of bridges, thereby escalating maintenance frequency and repair costs. In response to this challenge, the integration of innovative materials such as Ultra High-Performance Concrete (UHPC) is being explored for the development and implementation of maintenance and rehabilitation strategies. This study presents a comparative analysis between conventional methods and UHPC applications for bridge repairs, utilizing Life Cycle Cost Analysis (LCCA) to encompass both agency and user costs, and applies Monte Carlo simulation to account for the variability of the modeling factors. A practical case study illustrates the applicability of the LCCA methodology, revealing that the utilization of UHPC contributes to a reduction in the total life cycle cost for bridge maintenance and rehabilitation. Life expectancy, Average Daily Traffic (ADT), and the duration of construction activities during rehabilitation emerge as the most influential factors affecting life cycle costs. The main contributions of the study are the development of the life-expectancy model and step-by-step Life-Cycle Cost Analysis (LCCA) methodology. Findings from this study aim to identify cost-effective retrofitting techniques for maintaining bridges in a “State of Good Repair.”

The coordinated activities of collagen VI and XII in maintenance of tissue structure, function and repair: evidence for a physical interaction.

Collagen VI and collagen XII are structurally complex collagens of the extracellular matrix (ECM). Like all collagens, type VI and XII both possess triple-helical components that facilitate participation in the ECM network, but collagen VI and XII are distinct from the more abundant fibrillar collagens in that they also possess arrays of structurally globular modules with the capacity to propagate signaling to attached cells. Cell attachment to collagen VI and XII is known to regulate protective, proliferative or developmental processes through a variety of mechanisms, but a growing body of genetic and biochemical evidence suggests that at least some of these phenomena may be potentiated through mechanisms that require coordinated interaction between the two collagens. For example, genetic studies in humans have identified forms of myopathic Ehlers-Danlos syndrome with overlapping phenotypes that result from mutations in either collagen VI or XII, and biochemical and cell-based studies have identified accessory molecules that could form bridging interactions between the two collagens. However, the demonstration of a direct or ternary structural interaction between collagen VI or XII has not yet been reported. This Hypothesis and Theory review article examines the evidence that supports the existence of a functional complex between type VI and XII collagen in the ECM and discusses potential biological implications.

Abstract 3095: A high-throughput phenotypic screen to identify small molecule inhibitors of Werner helicase

Abstract Werner helicase (WRN) is a RecQ DNA helicase involved in genome maintenance and DNA damage repair. It has recently been shown to be essential to cancer cells with high microsatellite instability (MSI-H). In MSI-H cancer cells, WRN depletion was shown to induce DNA damage and disrupt mitoses, resulting in a distinct phenotype of enlarged and fragmented nuclei. Here, we present a high-throughput phenotypic screen to identify compounds that selectively induce enlarged nuclei in MSI-H cancer cells. In HCT116, an MSI-H colorectal cancer cell line, approximately 40% of cells exhibited enlarged nuclei when WRN was depleted using siRNA. In contrast, fewer than 10% of control cells displayed this phenotype. In HT29, a microsatellite stable (MSS) cancer cell line, no such difference in nuclear morphology was observed, suggesting that the phenotype is specific to MSI-H cells. We used high content imaging to screen our in-house diversity library of approximately 175,000 compounds in 384-well format. 4,260 compounds induced enlarged nuclei in HCT116 cells, a 2.4% hit rate. After re-screening hits in HCT116 along with two additional MSI-H cancer cell lines, SW48 and SNU-407, and counter-screening in HT29 cells, 144 hits were confirmed to specifically enlarge nuclei in MSI-H but not MSS cells. Using the ADP-Glo Kinase Assay, two of these compounds were confirmed to inhibit WRN ATPase activity, suggesting WRN inhibition as a potential mechanism for their specific effects in MSI-H cells. This screen will also identify compounds which selectively kill MSI-H cells through mechanisms beyond direct inhibition of WRN, including interaction with WRN complex members or other members of DNA damage repair pathways. Validation studies including the assessment of cell viability and DNA damage in a panel of MSI-H and MSS cell lines will be performed. Our study proposes a phenotypic screening strategy for identifying small molecules with the potential to target WRN and uncover additional novel mechanisms for treating MSI-H cancers. Citation Format: Christine A. Moomau, Yipin Lu, Xiaobin Zhang, Xiang Zhai, Lina Gu, Qing Sheng, Fang Li, Yaoyu Chen. A high-throughput phenotypic screen to identify small molecule inhibitors of Werner helicase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3095.

Energy-based availability warranty policy with considering preventive maintenance and learning-forgetting effect

Ensuring reliable operation and maximum the output is crucial for energy production systems. Traditional time-based availability (TBA) warranty policies often overlook some factors, such as energy loss and the experience gained during the maintenance activities. In this paper, an innovative warranty policy which focuses on the energy-based availability (EBA) is proposed, where imperfect preventive maintenance (IPM) and minimal repair (MR) are taken into account, and hybrid hazard rate model is adopted to describe the effect of preventive maintenance. In addition, the learning-forgetting effect during the maintenance is considered. On this basis, six types of single-objective and multi-objective models are established, and they are solved by genetic algorithm (GA) and non-dominated sorting genetic algorithm-II (NSGA-II), respectively. To illustrate the effectiveness of the proposed warranty policy, a numerical case of wind turbine gearbox is conducted. The results show that the proposed EBA warranty policy can gain around 0.29% energy more than TBA policy. Compared to single-objective models, multi-objective models can provide more selectable maintenance options. Additionally, sensitivity analysis indicates that by considering the learning-forgetting effect, the gearbox can achieve higher EBA and lower warranty cost.