Maintenance Work Research Articles

Equipment consumption prediction based on improved HOLT exponential smoothing method

In response to the prediction of equipment consumption, the Markov chain was used to improve the Holt index smooth method. The results show that the improved Holt exponential smoothing method makes the average relative error drop significantly, and the prediction accuracy of the model is improved significantly, providing a scientific decision basis for equipment demand in equipment maintenance and guarantee work.

Adjustable Robust Optimization for Water Distribution System Operation Under Uncertainty

AbstractThe optimal operation of water distribution systems (WDS) is a paramount objective for water utilities due to the substantial energy consumption associated with pumping. A major challenge in optimizing WDS operation is addressing uncertainties such as those related to consumer demands. Real‐time operation under uncertainty necessitates a dynamic approach that can utilize the newly observed information and adjust the operational policy accordingly. This study presents an adjustable robust optimization (ARO) approach to tackle this challenge. Unlike static optimization methods, ARO generates a decision rule policy that is dynamically adjusted as new data becomes available and the operational horizon evolves, thereby ensuring adaptability to changing conditions. Furthermore, the study includes a quantitative analysis of typical demand uncertainty that supports the formulation of the ARO model. The proposed method is evaluated through two case studies and compared with traditional folding horizon approaches. The results indicate that the ARO method is competitive with traditional methods in terms of objective value and surpasses them in terms of robustness. An additional advantage of the method is its offline operation capability which enables it to produce decision rules independent of real‐time programs. This feature facilitates various practical applications such as what‐if analyses, maintenance work planning, and preparation for other special events.

Assessing the Risk of Occupational Hazard Using the FMEA Tool Among Hospital Staff at Multispecialty Hospital

Considering the importance of occupational hazard assessment, this study has been performed to identify the risks for employees who especially undergo a major occupational hazard that affects their efficiency and productivity. The study aimed to assess the risk of occupational hazard using Failure Mode and Effect Analysis (FMEA) and strategy to modify the healthcare packages provided by the hospital to the staff. A survey and personal interviews were done at a private multispecialty hospital in Chennai using a descriptive study methodology. The survey included 150 hospital employees from four departments: CSSD (6 participants, covering all available samples), Maintenance (41 participants, chosen at random), Nursing (60 participants, chosen at random), and Housekeeping (43 participants, chosen at random). To collect data, a standardized questionnaire aligned with the Occupational Safety and Health Administration (OSHA) was used (https://www.osha.gov/laws-regs/standardinterpretations/1987-08-06). In addition, unstructured personal interviews with key workers were undertaken. The data revealed that CSSD workers encountered most of the stated dangers, with 100% admitting to workplace risks such as needle sticks, chemical allergies, the risk of burns, and awkward ergonomic postures. Maintenance workers reported a 54% risk of pain and discomfort, 32% of sleep loss following night shifts, and 37% of chemical risks. Nursing personnel cited poor ergonomic posture (68%) as a key concern, followed by sleep loss (62%), and the risk of cuts (52%). Housekeeping personnel cited hazards of falls (69%), poor ergonomic postures (40%), and infectious disease exposure (31%). The study emphasizes the need to address occupational health risks in healthcare settings by thoroughly reviewing the many occupational health hazards that impact healthcare professionals. However, it is important to remember that the study relied on data from the previous six months, potentially leaving out undetected risks. Furthermore, the study emphasized the impact of these dangers on healthcare personnel, emphasizing the problem of events being underreported inside the institution. Notably, the study emphasized the importance of paying close attention to occupational dangers such as needle sticks, chemical exposure, burns and ergonomic concerns in healthcare professionals' daily health management.

EFFECT OF DEICING SALT ON PERMEABILITY COEFFICIENT OF ASPHALT MIXTURE UNDER FREEZE-THAW CYCLE

The widespread use of deicing salt in road maintenance work not only protects the pavements, but also causes serious damage to it. This paper investigates and analyzes the influence of three different deicing salt solutions under three low-temperature env

Spinning Circle at the Mill

Spinning Circle at the Mill

Innovative requirements and evaluation methods for slab track design

With increasing train speeds and reduced time windows for maintenance work, the interest in the application of slab track technology to increase the capacity of high-speed railways has grown. Slab track may still be considered a relatively young technology, but with several different designs available on the market. Current research on slab tracks commonly focuses on improved methods. In contrast, the formulation of requirements, and evaluation towards these, are seldom investigated. In this paper, state-of-the-art simulation models are employed to illustrate and address the needs for innovative requirements in terms of structural integrity and robustness, life cycle cost (LCC) and environmental footprint of new and existing slab track designs. Based on demonstration examples, it is argued that current standards may lead to overly conservative designs inducing higher LCC and environmental footprint than necessary. Extensions of the standards in terms of LCC and environmental footprint are suggested. The conflict of interest between structural integrity and robustness, LCC and environmental footprint is discussed, and suggestions for how to optimise slab track structures are proposed.

Erosion resistant effects of protective films for wind turbine blades

Over the course of many years of use, impingement wear from dust, sand, and other materials can damage wind turbine blades, necessitating repairs and other maintenance work. Recently, wind turbine operators are turning to protective films, which allow such work to be completed more efficiently, as an alternative to the conventional approach of using paint to repair wind turbine blades. However, the erosion resistance characteristics of repaired blades remain unclear. In this study, we create paint- and protective film-coated samples to reproduce repairs, measure their erosion resistance, and study underlying factors in an effort to verify the erosion resistance of repaired materials and associated mechanisms. The low erosion resistance of GFRP can be significantly improved by applying a protective film made of a ductile material. Such material effectively protects the surface of the GFRP. Moreover, the erosion resistance of protective films made from polyurethane material is superior to that of paint. We recommend use of protective film with wind turbine blades when manufacturing blades and regular maintenance.

Development of compliant modular floating photovoltaic farm for coastal conditions

Floating photovoltaic (PV) farms can be constructed in coastal marine conditions for the abundant ocean space compared to reservoirs. New challenges may arise when extending existing designs of reservoir floating PV farms to coastal regions because of the complex environmental conditions, especially for the pontoon type floating PV systems. This study presents the methodologies for the design and verification of such floating PV farms based on the practical example of one of the world's largest nearshore floating photovoltaic farms off Woodlands in Singapore. This 5 MW pilot project aims to move floating PV farms from inland water to nearshore regions for future larger-scale deployments. The innovative floating system is adapted from the successful modular floating PV development at Tengeh Reservoir and improved to withstand harsher marine environmental conditions. This study comprehensively introduces various aspects of the development of the nearshore floating modular PV farm, including its design, verification via full-scale experimental testing and numerical studies, construction, and power generation performances. The floating PV system comprises standardized floating modules made of high-density polyethylene (HDPE) that support PV panels or operational and maintenance work. A compliant design allows the floating system to follow wave motion. A verification study was conducted through full-scale experimental tests and numerical simulations based on a representative subsystem of the floating PV farm, focusing on its hydrodynamic performance. Finally, this study presents and discuss the on-site operational energy production performance. This study may serve as a reference for developing large-scale floating PV farms in coastal marine conditions.

Maintenance scheduling at high-speed train depots: An optimization approach

Under the preventive maintenance policy, high-speed trains need to conduct periodical inspection/overhaul at dedicated depots, where maintenance facilities and maintenance crews are available. Due to the complicated structure of trains, the maintenance work is rich in a variety of types, characterized by mechanical components repaired, maintenance levels and etc. In practice, these types of maintenance work are integrated into maintenance packets, and different packets may require the specific types of crews. In this paper, a mixed integer linear programming model is proposed for the depot maintenance packet assignment and crew scheduling problem. The objective of the problem is to minimize the overall crew worktime, while the main constraints include the compatibility between maintenance packets and crew types, maintenance packet duration time and execution order, maintenance time window, and crew worktime limit. Besides, two families of valid inequalities are proposed to improve the baseline model. Computational experiments on a set of randomly generated instances show the effectiveness and efficiency of the improved model compared to the baseline one. Finally, a real-world case study from Shanghai South Depot is carried out to further validate the proposed approach. Improvements on both solution time and quality are achieved in contrast with the manual schedule.

Improving the efficiency of repair departments as a key element of the production process

In the past, maintenance and repair (MRO) was seen by many as a “necessary evil,” an activity that cost money but provided nothing in return. Twenty or more years ago, maintenance workers were among the lowest-paid employees in full-service manufacturing plants, even though their jobs required the most technical skill, knowledge, and specialized training. Initially, repairs were carried out as necessary and when equipment broke down, but the more extensively the same type of equipment was used, the more data on failures could be collected. This made it possible to improve the maintenance system - recommendations appeared on the frequency of repair work. In modern enterprises, maintenance and repair is recognized as a key element of the production process, which allows minimizing costs, increasing equipment uptime, increasing productivity, and identifying and eliminating losses.

Increasing Task Administration Efficiency by Means of a Customizable ICT Solution

In production companies, managers frequently deal with inefficiencies caused by employees learning about new tasks with a considerable delay. The paper focuses on solving the lack of real-time interaction in currently used task administration systems by means of an ICT solution. The main causes of the inefficiencies consist in insufficient real-time information on the sides of both workers and managers. Employees view updates in the information system randomly, thus increasing unnecessary periods of idle time, while their superiors are not fully informed about the status of tasks in progress and about current workload of individual workers. The presented ICT solution was developed for production companies and implemented for the purpose of administering production line failure records. The solution is based on informing employees about a new maintenance task online in real time, using a combination of the designed information system with a mobile phone. The presented system utilizes advanced information technologies – cloud messaging, mobile applications, and web applications. The employee will be equipped with a smartphone with a specially designed application. By a notification sent to the mobile phone, the employee will be immediately informed about the task assigned. As regards task administering, employees enter information about the phases of task execution and managers are informed about the status of executed tasks. Another key feature of the system is providing managers with managerial overviews and compiling reports in order to monitor a number of key indicators. The Unified Process (UP) methodology was used to design the information system. The system accelerates the process of receiving tasks by individual maintenance workers after a failure has been reported, an online overview of the status of work on failures, including a managerial overview of the work of individual workers and the total time spent on solving the task (e.g. a production line defect removal). The system is designed to be universally applicable in other workplaces.

The mediating role of religion and loneliness on the association between reminiscence functions and depression: a call to advance older adults' mental health.

Current literature lacks evidence about the relationship between reminiscence functions and depression and the mediating role of clinical constructs such as loneliness and religion. The study aimed to examine the mediating effects of loneliness and religion on the association between reminiscence functions and depression in a sample of older Jordanian adults. An anonymous online cross-sectional survey was employed to collect data from 365 older Jordanian adults. Convenience and snowball sampling methods were used to recruit participants through social media. In the depression model, Bitterness Revival and Intimacy Maintenance factors, educational level, and Intrinsic Religiosity were statistically significant predictors of depression. Bitterness Revival and Intimacy Maintenance factors, work sector, and Intrinsic Religiosity were statistically significant predictors of loneliness. Loneliness has a negative, partial mediating effect on Intimacy Maintenance and depression. Depression caused by significant losses in the Arab Jordanian environment might be mitigated by Intimacy Maintenance by reducing feelings of loneliness. Understanding how Intimacy Maintenance correlates with depression through loneliness could help psychiatric nurses develop psychosocial interventions that reduce depression among older adults.

Epidemiological study of work-related musculoskeletal disorders and related risk factors among automobile maintenance workers.

The automotive industry is labor-intensive, and workers are involved in highly repetitive tasks, long hours, and medium to low workloads, resulting in work-related musculoskeletal disorders (WMSDs), which have become a major health concern for workers in this industry. China is a major automotive country with tens of thousands of auto repair workers, but their conditions of WMSDs have been poorly reported. This work aimed to analyze the current prevalence of WMSDs and their associated risk factors among automobile maintenance workers. A total of 539 respondents from 50 automotive repair and maintenance companies in China were selected to investigate the prevalence of WMSDs via the modified Nordic Musculoskeletal Disorders Questionnaire. Chi-square test and logistic regression models were applied to analyze their associated risk factors. The total prevalence of WMSDs among 539 workers was 32.8%. The top three body parts for prevalence were the lower back (17.1%), neck (16.3%), and shoulders (14.5%). The highest prevalence of WMSDs was found in the neck (23.6%) and lower back (14.3%) for sheet metal workers and mechanics, respectively, whereas painters had the highest prevalence of WMSDs in the lower back and feet (both at 15.4%). Logistic regression analysis showed that females were at higher risk of WMSDs than males (OR 5.027, [95% CI] [1.278-19.772], p < 0.05). Workers subjected to uncomfortable positions were at increased risk of WMSDs (OR 1.79, [95% CI] [1.333-2.410], p < 0.01). The prevalence of WMSDs is high among automotive maintenance workers, with the highest prevalence in the lower back (17.1%). Uncomfortable working postures and frequent repetitive movements with lower limbs and ankles at work may be important risk factors.

Vision Image Monitoring on Transportation Infrastructures: A Lightweight Transfer Learning Approach

Vision monitoring of distress has emerged as a new trend in intelligent transportation infrastructure systems, including roads and bridges. Recently, transfer learning methods and lightweight networks have been used to realize efficient distress identification without large amount of human-labor work. This paper proposed an engineering approach that integrated transfer learning with lightweight models to classify and detect concrete bridge distresses. Two datasets named Distress Dataset of Asphalt Pavement (DDAP) with 2500 asphalt pavement distresses images and Distress Dataset of Concrete Bridge (DDCB) with 906 concrete bridge distresses images were used. The lightweight models MobileNet and MobileNet-SSD were employed to conduct 6 comparative experiments for exploring the model performance with different transfer learning modes (Mode I and II) and procedures (one-step and two-step procedure) in classification and detection tasks. Based on the comparison of the results, the optimum model for two tasks was respectively recognized. For classification task, the model directly transferred specific parameters of partial convolution layers from ImageNet-based model achieved the highest accuracy of 97.8%. For detection task, the two-step transfer learning model using an intermediate transfer learning step trained by DDAP reached a mean average precision of 87.16%. The proposed approach has the application potential for practical road inspection work in intelligent transportation infrastructure maintenance.

Experiment Investigation and Influence Evaluation of Permeability Ability Attenuation for Porous Asphalt Concrete under Repeated Clogging Conditions

One of the problems that limit the development of porous asphalt concrete (PAC) is that the pores become clogged, which leads to severe deterioration in its permeability performance. This paper focuses on PAC’s permeability characteristics under repeated cycles of clogging. First, sand (S), clay (C), and sand and clay mixtures (S + C) were used as clogging materials for repeated clogging tests. Then, the permeability coefficients in the initial state and after clogging were measured with an improved permeability device. Based upon porosity, maximum nominal particle size, and clogging materials, the paper analyzed the permeability regulation of PAC under repeated clogging conditions. In addition, we compared the restoration effects of vacuum cleaning, high-pressure cleaning, and surface cleaning with cleaning tests and proposed a response surface methodology prediction model. Finally, the particle size distribution of sensitive particles that cause different porosities in PAC clogging was explored. The results showed that the initial permeability coefficient and the permeability coefficient with PAC’s repeated clogging increased with the increase in the nominal maximum particle size and porosity. PAC clogged by sand has the greatest rate of reduction in the coefficient of permeability. In addition, we suggested that in PAC pavement maintenance work, water is first sprinkled to wet the road, then high-pressure cleaning used, and finally vacuum cleaning. The prediction model is reliable and the cleaning method has the most significant effect on the permeability coefficient. Further, the particle size distribution that caused PAC-13 and PAC-10 clogging ranged from 0.15 to 2.36 mm and 0.075 to 2.36 mm, respectively.

Energy-Efficient Resource Allocation in Aerial Base Stations

Drones, or unmanned aerial vehicles, can be used as air base stations (UAV-BSs) for telecommunications. They prove useful in situations where the network is overloaded or unavailable due to natural disasters or maintenance work. UAV-BSs grant access to user/IoTs sensors on the ground, but their electromagnetic signals may suffer losses because of their dynamic capacity to provide access at different altitudes. These losses lead to transmission impairments, such as attenuation, fading, and distortion. To overcome these issues and improve signal quality, the UAV-BS position must be optimized. However, finding the optimal placement is a challenge, and a wide range of strategies employing different approaches have been adopted. In this study, we proposed a 3D positioning strategy for UAV-BSs that serves the maximum number of users with the smallest number of UAV-BSs. Results showed that the proposed heuristic could find the best position and altitude for the UAV-BSs, provide network access for mobile user/IoTs (Internet of things) sensors, maximize the number of devices connected to the UAV-BSs, and guarantee a minimum throughput for users. The proposed heuristic not only performs well in terms of coverage and performance, but is also more energy-efficient than other algorithms found in the literature.

Study and Analysis of Highway Failure and Their Maintenance

Abstract: Maintaining highways is crucial to ensure road surfaces are safe and smooth for drivers, ultimately loading to efficient and cost-effective transportation. Regular maintenance helps prevent accidents and reduces theoverall cost of road repairs in the long run. The investigation found that the authority of RCC performs their maintenance work in one year when allocated funds are available. Many types of road failures oc, such as cracks, pot-holes, ravelling, water bleeding, corrugation and showing, depression, and rutting. The possible causes of flexible pavement failures are improper bituminous mixes with poor quality materials, heavy traffic loads,heavy rainfall, and bad drainage on pavement. The failures are gradually raised due to a lack of proper planning, inspection,and treatment. These failures create different types of disadvantages like traffic jams, discomfort to the passengers aswell as drivers, increasing vehicle operating, maintenance costs, etc

Analysis of the development mechanisms of a large-hail storm event on the Adriatic Sea

A severe weather event is analyzed in terms of cell development, dynamics, and thermodynamics. The Mediterranean region is sporadically affected by severe weather events causing damage and injuries. An unusual and severe weather event hit Italy on July 9–10, 2019 causing heavy damage. The meteorological structure was characterized by a trough entering the eastern Mediterranean area from northeastern Europe affecting Italy and the Balkans with cold-air advection over the Adriatic Sea. On the morning of 10 July 2019, a supercell developed along the coast north of Pescara (central Italy), producing intense rainfall (130 mm/3 h) and a heavy hailstorm with hailstones larger than 10 cm in diameter. In this work, the dynamics and thermodynamics for triggering and maintenance of the supercell are investigated using the numerical model WRF (Weather Research and Forecasting system), satellite, radar-data, soundings, and ground observations. In the companion paper, the role of SST and orography was investigated assessing that the SST spatial representation, its anomaly distribution and the topography play a key role in triggering the supercell (Ricchi et al., 2023). In this paper, high spatial and temporal-resolution model simulations and observations are used to investigate the characteristics of the supercell by analyzing both its horizontal and vertical structure. The hailstone characteristics are assessed by using the HAILCAST parameterization in which its performance and reliability are discussed.

Analysis of the Application of Micro Steel Pipe Pile Technology in Emergency Maintenance of Ordinary National and Provincial Trunk Highway Subgrade

A provincial road in Guizhou Province experienced cracking and bursting of retaining walls, roadbed subsidence, and road surface cracking, with a rapid trend of disease development. After multiple on-site inspections, it was decided to implement emergency maintenance of the roadbed. For sudden disaster sections that affect traffic safety, emergency plans should be initiated and emergency maintenance and repair work should be carried out in a timely manner. The treatment plan adopts micro steel pipe piles to reinforce the roadbed, demolish and rebuild the original retaining wall, and finally restore the road surface, drainage, and traffic safety facilities.

Semi-automated visualization method for visual inspection of buildings on BIM using 3D point cloud

Regular diagnosis of a building can identify structural safety and latent hazards and establish efficient maintenance strategies. Traditional diagnoses are based on personal perspectives or knowledge of experts; therefore, they are laborious, time-consuming, and subjective. Moreover, the results may be unreliable. In addition, an undefined data format makes its practical use difficult. This study proposes a visualized semi-automated approach to extract building condition data and integrate them with BIM using Dynamo. The proposed framework uses Python code to improve efficiency when extracting coordinates. First, 3D point cloud data on the external walls of buildings obtained using a laser scanner are processed, and the relevant information, such as coordinates, is extracted. Second, the BIM model is implemented based on a point cloud using supplementary modeling tools. Finally, the extracted defects are modeled as new objects, and each BIM object is colored according to the modified criteria. To validate the feasibility of the proposed method, it was applied to actual buildings, improving the efficiency and accuracy of building inspections. This is expected to facilitate a reduction in building maintenance work and the identification of deterioration patterns.