МЕТОДИКА ВИЗНАЧЕННЯ ПАРАМЕТРІВ СИСТЕМИ ТЕХНІЧНОГО ОБСЛУГОВУВАННЯ І РЕМОНТУ ТЕХНІЧНИХ СИСТЕМ

In recent years, research on wind turbine maintenance task scheduling increases gradually. However, most studies are based on simple operation rules, and focus on small laboratory instance. The outcome of these studies cannot be applied to practice straightforwardly. To address this problem, this paper schedules the maintenance of wind turbines by identifying the priority of different maintenance tasks. First of all, the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method is used to determine the priority of the maintenance tasks by considering scheduling rules of maintenance task type, importance of maintenance task, remaining time, task maintenance time and waiting time before maintenance. Then, the task scheduling model based on task priority is constructed, and the feasibility of the model is validated by a practical case study. The result shows that the model can solve complex problems in a simple way, and provide reference for the maintenance engineer to determine the maintenance task scheduling scheme.

Fortran programs for the time-dependent Gross–Pitaevskii equation in a fully anisotropic trap

Abstract3D shape acquisition of large facilities, such as industrial plants and power plants, has been receiving increasing attention for simulating complicated maintenance and repair tasks. It is widely recognized that model-based planning based on 3D CAD reduces the rework of maintenance tasks to a large extent. The state-of-the-art phase-based laser scanners are very promising to efficiently capture point-clouds of large facilities; because they can produce hundreds of millions point data in several minutes. However, point data captured from the phase-based scanner tend to include large noise components and quite a lot of outliers. In addition, very large memory space is required to generate solid models by processing very large point-clouds. Therefore, it is preferable to develop techniques that can extract surface primitives, such as planes, cylinders, cones, spheres, and tori from very noisy and large-scale point-clouds. This paper introduces a robust streaming smoothing operator for extracting surf...

Objectives/Scope This document presents the application steps of the repair and structural reinforcement system with high-performance polymer and composite material. Without the need to shut-down the offshore platform, this technology is based on ASME and ISO international standards with high safety and applicable in classified areas where hot-work permit is not obtainable. Methods, Procedures, Process The methods and procedures are applied and carried out exclusively for each application, after a judicious risk assessment. Recently, a 14" super duplex pipe carrying seawater line, operating at 8 bar pressure, on an oil platform located in Ghana showed active leak. In order to carry a conventional repair, (replacement of the problematic section or conventional hot welding) the shut-down of production would be necessary. Furthermore, the conventional method was not applicable due to the potentially explosive atmospheric conditions. Based on Part 4 of the ASME PCC-2 standard, the repair system was engineered to a 10-year lifespan and carried out with absolute safety. The procedure consists of a surface preparation, leak containment and structural reinforcement on the defective area of the pipe. All the steps in the aforementioned procedure were cold-work type and without the need to shut-down, therefore without loss of production. The equations used to calculate the thickness and length of the repair system with composite material, as well as the risk assessment, were in accordance to the referenced standards. Results, Observations, Conclusions The repair system was applied with success without the need to shut-down the production and was considered permanent by ABS. The hardness of the composite, measured after 24 hours, indicates full cure of the repair as predicted by the procedure and quality standards. Therefore, the leak was 100% sealed and the area was structurally reinforced in line with the engineering plan and without any loss of production. Novel/Additive Information The integrity of aging offshore assets is a common global problem due to the constraint of concurrent activities in a production environment. This methodology using composite materials in association with asset integrity management without shutdown production has gained recognition to be a long-term solution. The implementation of the repair and structural reinforcement system with high-performance polymer and composite material provides cost reduction, significant health, safety and environmental advantages as it enables immediate attention for the defect, on top of the benefit to avoid the loss of production.

Magnesium alloys are used in the aeronautical sector due to their excellent strength/weight ratios, motivated by the reduction of weight that their use entails. In this sector, drilling is one of the most common operations, if not the most, due to the large number of holes that are used in joining processes, mainly by riveting. The appearance of cracks is a risk to the structural safety of the components, such that it is necessary to regularly check them for maintenance and/or repair tasks. The present study tries to determine the optimization of the characteristics of the twist drills, which are re-sharpened successively to restore the cutting edge after use, as well as the operating parameters in machining. For this purpose, a full factorial experimental design was established, analyzing through the analysis of the variance (ANOVA) the response variables. Surface integrity was considered to carry out a global vision of the quality obtained, covering as response variables the surface roughness, the size of the burrs and the modification of the hardness produced, in addition to a topological characterization by optical means of machined surfaces. The main conclusion is that it is possible that the geometric optimization of the tools and the operating parameters considered in this study in drilling processes allow them to be performed, while maintaining quality and environmental requirements, and at the same time, maximize the productivity of operations.

Human-centered Evaluation of Shared Teleoperation System for Maintenance and Repair Tasks in Nuclear Power Plants

Subsea applications recently received increasing attention due to the global expansion of offshore energy, seabed infrastructure, and maritime activities; complex inspection, maintenance, and repair tasks in this domain are regularly solved with pilot-controlled, tethered remote-operated vehicles to reduce the use of human divers. However, collecting and precisely labeling submerged data is challenging due to uncontrollable and harsh environmental factors. As an alternative, synthetic environments offer cost-effective, controlled alternatives to real-world operations, with access to detailed ground-truth data. This study investigates the potential of synthetic underwater environments to offer cost-effective, controlled alternatives to real-world operations, by rendering detailed labeled datasets and their application to machine-learning. Two synthetic datasets with over 1000 rendered images each were used to train DeepLabV3+ neural networks with an Xception backbone. The dataset includes environmental classes like seawater and seafloor, offshore structures components, ship hulls, and several marine growth classes. The machine-learning models were trained using transfer learning and data augmentation techniques. Testing showed high accuracy in segmenting synthetic images. In contrast, testing on real-world imagery yielded promising results for two out of three of the studied cases, though challenges in distinguishing some classes persist. This study demonstrates the efficiency of synthetic environments for training subsea machine learning models but also highlights some important limitations in certain cases. Improvements can be pursued by introducing layered species into synthetic environments and improving real-world optical information quality-better color representation, reduced compression artifacts, and minimized motion blur-are key focus areas. Future work involves more extensive validation with expert-labeled datasets to validate and enhance real-world application accuracy.

Magnesium alloys are increasingly used due to the reduction of weight and pollutants that can be obtained, especially in the aeronautical, aerospace, and automotive sectors. In maintenance and repair tasks, it is common to carry out re-drilling processes, which must comply with the established quality requirements and be performed following the required safety and environmental standards. Currently, there is still a lack of knowledge of the machining of these alloys, especially with regards to drilling operations. The present article studies the influence of different cutting parameters on the surface quality obtained by drilling during repair and/or maintaining operations. For this propose, an experimental design was established that allows for the optimization of resources, using the average roughness (Ra) as the response variable, and it was analyzed through the analysis of variance (ANOVA). The results were within the margins of variation of the factors considered: the combination of factor levels that keep the Ra within the established margin, those that allow for the minimization of roughness, and those that allow for the reduction of machining time. In this sense, these operations were carried out in the most efficient way.

The main goal of the UNION ESPRIT Basic Research Action is to develop methods for increasing the autonomy and intelligence of underwater remotely operated vehicles (ROVs). The project focuses mainly on the development of coordinated control and sensing strategies for combined manipulator and vehicle systems. Both fundamental theories and methods for the design of these heterogeneous systems are investigated. A complex canonical mission in the field of offshore inspection maintenance and repair tasks was chosen as an integration guideline of all the results.

Currently, a great number of modern passenger rolling stock is being put into operation. The organization of service maintenance and repair of passenger rolling stock is one of the key objectives for a rail carrier. At present, maintenance and repair costs constitute about 75% of the total expenses of carrier companies. This paper examines a simulation modeling system designed to integrate the scheduling tasks of service maintenance and repair of passenger rolling stock, and the main stages of building a discrete-event model of a passenger rolling stock maintenance system using the AnyLogic environment. The simulation model will allow recreating the system and obtaining the performance indicators for the service maintenance strategy. The modeling results will enable carrier companies to evaluate the service maintenance and repair strategy, which affects making managerial decisions.

Software maintainers have long been acutely aware of the challenges involved in managing software change processes. Activities such as software migration, restructuring and reengineering all involve source code modification. They rely heavily on analysis and comprehension of the complex system structures and interactions that characterize both legacy and modern software systems. It is widely accepted that tools that support software analysis and maintenance tasks would go a long way towards addressing the constraints that software developers and maintainers work with on a day-to-day basis. Nevertheless, despite an abundance of tools, not many are used by practitioners and very few are considered essential for a particular development or maintenance task. This workshop examined design issues related to the development and application of tools to support software analysis and maintenance

Robots and automation techniques are used in many industries for a long period because of the economic advantages and efficiency. Though the railway has a long history compared to other transportation systems, it still lacks wide application of modern technologies such as robots and AI. Track maintenance using robotic technologies has gained some attraction from both infrastructure managers and researchers due to safety and cost benefits. A Railway Inspection and Repair System (RIRS) has been proposed using commercially available Unmanned Ground Vehicles (UGV) and an industrial manipulator for the railway track inspection and repair tasks. The use of a specially designed trolley enables the on-track and off-track navigation capability of RIRS. The infrastructure in railway is very diversified and unique in size, shape, and remoteness compared to other industries. This research investigates the unique challenges to the operation of RIRS imposed by the railway infrastructure.

Geophysical Inverse Theory and Regularization Problems

A rebuttable presumption that lot owners contributed to the construction of a utility system arises only if certain factors reveal intent by a developer to recover its capital construction costs twice. This column discusses the case of Puhi Sewer and Water company, which was incorporated as a subsidiary of a developer to operate a sewage facility for an extensive development project on Kauai. The sewer facility was then transferred to Puhi. Puhi applied for a certificate of public convenience and necessity and for approval of the proposed rates, rules and regulations. Puhi sought to include the $10 million cost of construction in its rate base. The public utility commission denied the proposed rate because of a presumption that the cost of the facilities was passed on as part of the cost of lots in the development. Puhi appealed. The appellate court said that factors that give rise to the presumptions were not present in this case. The court remanded the case to the commission to determine whether the cost of building the facility was included in the purchase price of the lots.

Blast response and safety evaluation of a composite column for use as key element in structural systems