Elevated Maintenance Research Articles

Sea-level rise versus salt marsh colonization: The adversarial game of self-organized elevation maintenance in tidal marsh

Tidal marshes globally face escalating threats from rising sea levels. As critical determinants of tidal marsh platform elevation maintenance, the contributions of marsh soil compaction and subsidence (SCS) are often overshadowed by vertical accretion (VA). Here, we reveal the pervasive presence of the SCS within tidal marshes and its driving forces. Our results demonstrate that while vegetated regions can organize more efficient sediment accumulation, thereby promoting marsh elevation rise, they also contribute to an increase in SCS occurrences, which somewhat hinders marsh elevation growth. Through the established empirical model of SCS, we found that the amount of SCS in the investigated marshes with vegetation cover is twice that of marshes without vegetation. Therefore, from the perspective of SCS, it is imperative to account for the detrimental impact of vegetation on marsh elevation, as we have uncovered that this oversight may lead to an underestimation of the vulnerability of the investigated tidal marsh ecosystem by approximately 13.55 %. We also find that the adversarial game between vegetation colonization and sea-level rise governs the SCS in the self-organization of tidal marshes, but the intensifying inundation from sea-level rise ultimately determines the fate of the SCS. Our study emphasizes the crucial role of the game between sea-level rise and vegetation colonization in the self-organized elevation maintenance of tidal marshes.

Comparative analysis of novel data‐driven techniques for remaining useful life estimation of wind turbine high‐speed shaft bearings

AbstractAs the global momentum for wind power generation accelerates, the industry faces substantial challenges due to premature failures in wind turbine components. These failures, particularly in critical elements like the high‐speed shaft bearing, lead to significant operational losses, including unplanned downtime and elevated maintenance costs. To mitigate these issues, it's crucial to have precise predictions of the remaining useful life (RUL) of these components, enabling timely interventions and more efficient maintenance schedules. This article proposes advanced, data‐driven approaches for estimating the RUL of wind turbine high‐speed shaft bearings, utilizing cutting‐edge techniques such as long short‐term memory (LSTM), bidirectional LSTM (BiLSTM), gated recurrent units (GRU), and random forest (RF) algorithms. Our analysis leverages vibration data from a 2 MW wind turbine equipped with a 20‐tooth pinion gear, providing a thorough validation and comparison of these methodologies against traditional models. Our results reveal that the LSTM and BiLSTM models excel in both accuracy and computational efficiency for predicting RUL and enhancing system prognosis, surpassing the performance of conventional RF and GRU methods. This research underscores the potential of our innovative data‐driven strategies to develop effective RUL estimation algorithms, significantly advancing wind turbine proactive operation and maintenance operations.

Postmortem CT and autopsy findings in an elevator-related death: a case report

AbstractElevator-related fatalities and injuries are rarely discussed. Falls have been identified as the first cause of mortality in the majority of these accidents. Evidence suggests that many elevator accidents may be attributed to inadequate equipment maintenance or malfunctions of the devices. This study examines a case involving an elevator maintenance worker found within an elevator shaft, using postmortem computed tomography (PMCT) along with a full autopsy. The autopsy revealed that the cause of death was severe polytrauma resulting from dragging, compression, and crushing mechanisms, which resulted in a dislocated skull and multiple thoraco-abdominal injuries, including exposed organs and viscera. Detailed examination identified a cranio-encephalic crush, leading to a significant alteration in the physiognomy of the facial structures. Additionally, PMCT revealed complex spinal fractures, such as a Jefferson fracture and a complete Chance fracture at the D6 vertebra, accompanied by spinal deviation proximal to the fracture site. Autopsy findings corroborated these PMCT results. A multidisciplinary approach, including PMCT, is proposed as a strategic method for the comprehensive reconstruction of such accidents, facilitating the collection of extensive data.

Influence of pH value on erosive wear of 3D-printed polylactic acid for multiphase flow

Abstract Slurry erosion presents a critical challenge in hydrocarbon and cement processing industries, as well as in abrasive water jet cutting systems, leading to diminished operational efficiency and elevated maintenance costs. This study investigates the erosive wear behavior of Poly-Lactic Acid (PLA) fabricated with varying infill microtextures—zigzag, concentric, and grid—under diverse pH conditions (2.73, 7.75, and 10.15) using garnet particles as the erodent. The results demonstrate that optimal operational conditions for PLA are achieved with a grid microtexture, a pH of 7.75, and a 325 μm erodent size. Conversely, the most severe wear occurs under a pH of 10.15, a 600 μm erodent size, and a zigzag microtexture. The grid microtexture is the most effective in minimizing erosion, while the zigzag pattern shows a 16.68% increase in wear when compared to the grid microtexture. Additionally, a shift from a slightly basic to a highly acidic environment increases wear by 1%, whereas a transition to a highly basic environment leads to a 32.6% increase in erosion within the grid microtexture. The study highlights the significant contributions of infill microtexture (64%), erodent size (23.7%), and pH value (11%) to the overall erosion rate.

『스마트상점 기술 도입』이 소상공인 점포의 매출과 만족도에 미치는 영향

This study decomposes the local gap through the oaxaca factor analysis to find out how differences in housing prices affect the management costs with data the average value of three-year management costs between 2014 and 2016 to 536 complexes in three Gangnam and Gangbuk districts in Seoul. The results of the analysis of 290 complexes in three Gangnam and 246 complexes in three Gangbuk districts are as follows. First, housing prices did not affect administrative costs within the region, but were variables that affected data pooling. Second, when compared with the three Gangnam districts, the results of the characteristic coefficient, which can be explained by the characteristics of the complex and the external environment, showed that the gap in the management cost increased when the number of security personnel, repair and maintenance costs, elevator maintenance cost, floor area ratio, and 60m2 or more to 85m2. Third, the factors behind the gap between Gangnam 3 districts, which have higher housing prices than Gangbuk 3 districts, were confirmed to be the number of security personnel, repair costs, floor area ratio and elevator maintenance costs, and the higher the size and income of their holdings, the more they lived in Gangnam 3 districts, where local infrastructure was expanded, causing social inequality due to differences in housing welfare, such as safety, comfort and convenience.

Virtual‐reality system for elevator maintenance education: Design, implementation and evaluation

AbstractWith the rapid development of information technology, new educational models using virtual reality technology have received widespread attention from relevant researchers. In the field of vocational education, vocational colleges and training institutions can effectively mobilize students' learning initiative and improve their learning efficiency by using virtual reality technology. This study details the development process and system evaluation of a bespoke virtual reality system that offers a solution to the issues of uncertainty regarding hazards, high teaching expenses, and spatial constraints inherent in the practical training of elevator maintenance. By establishing a virtual environment that is highly reproducible and designing abundant interaction methods, this system facilitates students in attaining mastery over the structural make‐up of elevators, the principles of their operation, and the techniques involved in calibrating elevator governors. The system underwent testing by multiple users, and the satisfaction level of the system was ascertained through a questionnaire study, while the effectiveness of the system was evaluated using independent samples t test for data statistics concerning students' performance. The results of the study indicate that the system gained widespread praise among users, and it notably enhanced the students' learning drive, practical abilities, and on‐site adaptability.

Using vulnerability assessment to characterize coastal protection benefits provided by estuarine habitats of a dynamic intracoastal waterway.

The existence of coastal ecosystems depends on their ability to gain sediment and keep pace with sea level rise. Similar to other coastal areas, Northeast Florida (United States) is experiencing rapid population growth, climate change, and shifting wetland communities. Rising seas and more severe storms, coupled with the intensification of human activities, can modify the biophysical environment, thereby increasing coastal exposure to storm-induced erosion and inundation. Using the Guana Tolomato Matanzas National Estuarine Research Reserve as a case study, we analyzed the distribution of coastal protection services-expressly, wave attenuation and sediment control-provided by estuarine habitats inside a dynamic Intracoastal waterway. We explored six coastal variables that contribute to coastal flooding and erosion-(a) relief, (b) geomorphology, (c) estuarine habitats, (d) wind exposure, (e) boat wake energy, and (f) storm surge potential-to assess physical exposure to coastal hazards. The highest levels of coastal exposure were found in the north and south sections of the Reserve (9% and 14%, respectively) compared to only 4% in the central, with exposure in the south driven by low wetland elevation, high surge potential, and shorelines composed of less stable sandy and muddy substrate. The most vulnerable areas of the central Reserve and main channel of the Intracoastal waterway were exposed to boat wakes from larger vessels frequently traveling at medium speeds (10-20 knots) and had shoreline segments oriented towards the prevailing winds (north-northeast). To guide management for the recently expanded Reserve into vulnerable areas near the City of Saint Augustine, we evaluated six sites of concern where the current distribution of estuarine habitats (mangroves, salt marshes, and oyster beds) likely play the greatest role in natural protection. Spatially explicit outputs also identified potential elevation maintenance strategies such as living shorelines, landform modification, and mangrove establishment for providing coastal risk-reduction and other ecosystem-service co-benefits. Salt marshes and mangroves in two sites of the central section (N-312 and S-312) were found to protect more than a one-quarter of their cross-shore length (27% and 73%, respectively) from transitioning to the highest exposure category. Proposed interventions for mangrove establishment and living shorelines could help maintain elevation in these sites of concern. This work sets the stage for additional research, education, and outreach about where mangroves, salt marshes, and oyster beds are most likely to reduce risk to wetland communities in the region.

FOA-BDNet: A behavior detection algorithm for elevator maintenance personnel based on first-order deep network architecture

<p>The operation space of the vertical lift shaft is small, the components are complex, the occluding and different behavior space characteristics are similar, and the unsafe behavior is not easy to detect, which makes the operation safety of maintenance personnel in the elevator greatly threatened. This paper proposes an elevator maintenance personnel behavior detection algorithm based on the first-order deep network architecture (FOA-BDNet). First, a lightweight backbone feature extraction network is designed to meet the online real-time requirements of elevator maintenance environment monitoring video stream detection. Then, the feature fusion network structure of "far intersection and close connection" is proposed to fuse the fine-grained information with the coarse-grained information and to enhance the expression ability of deep semantic features. Finally, a first-order deep target detection algorithm adapted to the elevator scene is designed to identify and locate the behavior of maintenance personnel and to correctly detect unsafe behaviors. Experiments show that the detection accuracy rate on the self-built data set in this paper is 98.68%, which is 4.41% higher than that of the latest target detection model YOLOv8-s, and the reasoning speed reaches 69.51fps/s, which can be easily deployed in common edge devices and meet the real-time detection requirements for the unsafe behaviors of elevator scene maintenance personnel.</p>

Development of a Pre-prediction Model for Elevator Maintenance Quality and Evaluation of the Influence of Detailed Quality Factors Using Logistic Regression Analysis

Development of a Pre-prediction Model for Elevator Maintenance Quality and Evaluation of the Influence of Detailed Quality Factors Using Logistic Regression Analysis

Aligning expectations and perceptions of elevator maintenance stakeholders: an application of expectation confirmation theory

ABSTRACT A seamless performance of elevators is necessary for building owners (BOs) as it promotes end-user satisfaction, thus, they form some expectations from elevator maintenance contractors (EMCs). Coherence between the expectations of BOs and perceptions of EMCs promotes BOs satisfaction and facilitates the end users. This research aims to compare the opinions of the BOs with EMCs. Using the premise of expectation confirmation theory, the expectations of BOs from EMCs were determined by conducting a content analysis of ‘Requests for proposals (RFPs) ’. Afterwards, statistical analysis was conducted on questionnaire survey to determine the perceptions of EMCs regarding these expectations. Main expectations of BO include prompt response to callbacks, adequate equipment performance, effective execution of assigned duties and responsibilities, and attaining the specified performance thresholds. Questionnaire analysis revealed that apart from callbacks, the remaining three expectations were wholeheartedly received by the EMCs. Besides, several duties signifying these expectations were not considered essential by the EMCs. This research contributes to the literature by identifying the expectations of BOs and the perceptions regarding the same from EMCs perspective. Hence, BOs can emphasize more on those expectations in the RFPs and EMCs can align their maintenance strategies with BOs expectations.

Evidence for a maintenance cost for birds maintaining highly flexible basal, but not summit, metabolic rates

Reversible phenotypic flexibility allows organisms to better match phenotypes to prevailing environmental conditions and may produce fitness benefits. Costs and constraints of phenotypic flexibility may limit the capacity for flexible responses but are not well understood nor documented. Costs could include expenses associated with maintaining the flexible system or with generating the flexible response. One potential cost of maintaining a flexible system is an energetic cost reflected in the basal metabolic rate (BMR), with elevated BMR in individuals with more flexible metabolic responses. We accessed data from thermal acclimation studies of birds where BMR and/or Msum (maximum cold-induced metabolic rate) were measured before and after acclimation, as a measure of metabolic flexibility, to test the hypothesis that flexibility in BMR (ΔBMR), Msum (ΔMsum), or metabolic scope (Msum − BMR; ΔScope) is positively correlated with BMR. When temperature treatments lasted at least three weeks, three of six species showed significant positive correlations between ΔBMR and BMR, one species showed a significant negative correlation, and two species showed no significant correlation. ΔMsum and BMR were not significantly correlated for any species and ΔScope and BMR were significantly positively correlated for only one species. These data suggest that support costs exist for maintaining high BMR flexibility for some bird species, but high flexibility in Msum or metabolic scope does not generally incur elevated maintenance costs.

A paradigm shift in efficiency and service for commercial buildings

Best-in-class facilities management (FM) is all about high-quality service at a speed faster than ever before. This paper uses case studies to examine in detail the following technologies: indoor mapping and asset tracking, digital kiosks, hotelling and workspace surveying, elevator maintenance auditing, water leak detection, NanoSeptic button covers, 3D virtual tours of buildings, artificial intelligence (AI) for preventive maintenance, emergency light testing, construction management platform, lease abstracting data and analytics and autonomous vacuum systems. Each case study provides a description of the technology, the scope of implementation and the results of each endeavour. The reader will understand ten new technologies and be able to navigate the implementation details to set themselves up for the best chance to succeed.

Trends in surface elevation and accretion in a retrograding delta in coastal Mississippi, USA from 2012–2016

The Grand Bay estuary is in the north-central Gulf of Mexico and lacks riverine sediment input for marsh elevation maintenance. This study quantified trends in surface elevation change and accretion along an elevation gradient within the estuary. Elevation change rates were compared to short (13.71 mm/yr; 95% CI: -2.38–29.81), medium (6.97 mm/yr; 95% CI: 3.31–10.64), and long-range (3.50 mm/yr; 95% CI: 2.88–4.11) water level rise (WLR) rates for the region. Elevation change rates ranged from 0.54 mm/yr (95% CI: -0.63–1.72) to 5.45 mm/yr (95% CI: 4.27–6.62) and accretion rates ranged from 0.82 mm/yr (95% CI: -0.16–1.80) to 3.89 mm/yr (95% CI: 2.90–4.89) among marsh zones. Only the elevation change rate at a Juncus roemerianus marsh located high in the tidal frame was lower than long- (P < 0.001) and medium-range WLR rates (P < 0.01). The elevation change rate at a lower elevation J. roemerianus marsh was higher than the long-range WLR rate (P < 0.05). No marsh zones had elevation change rates that were significantly different from short-range WLR. These results suggest that J. roemerianus marshes higher in the tidal frame are the most vulnerable to increases in sea level. Lower elevation marshes had higher rates of elevation change driven by sediment accretion and biogenic inputs. Other local research suggests that shoreline erosion is a threat to marsh persistence but provides elevation capital to interior marshes. Marsh migration is a potential solution for marsh persistence in this relatively undeveloped area of the Gulf Coast.

The Causal Factors of Elevator Maintenance: A Perspective from Saudi Arabia Healthcare Facility Management

Maintenance is crucial for healthcare facilities in terms of both the continuity of operations and annual costs. Many maintenance issues are associated with design decisions that pave the way for added costs in later lifecycle stages. Some systems, e.g., elevators, are sources of maintenance costs; additionally, elevator outages are significant issues for multi-floor healthcare facilities. Considering the maintainability of elevators from the early design stages helps to highlight potential maintenance issues in later stages. This also assists in mitigating costs by avoiding design decisions that result in future maintenance costs. This research uses the expertise of facility managers who have experience with maintenance issues resulting from design decisions. A list of 35 elevator maintenance issues caused by design flaws is presented in this paper, based on the literature and semi-structured interviews with a representative sample of six healthcare facility management experts. Then, a questionnaire using convenience sampling was conducted with facility management professionals to evaluate and rank the maintenance issues. While 60 professionals responded, only 30 attempted the four-parameter evaluation of all listed maintenance issues. The results of the questionnaire determined elevator car jams, sudden stops, and working space conditions to be the most critical issues faced by facility managers in healthcare facilities. The output of this study can help designers of new healthcare facilities to avoid decisions that result in unwarranted maintenance issues with costly impacts.

Introduction of an Elevator Guide Shoe with Position and Lateral Force Monitoring Function

Abstract When the elevator guide rail is deformed or the building body is inclined, the car will produce a certain transverse force relative to the guide rail, resulting in serious wear on one side of the guide shoe. Since the existing guide shoe is fixed, when the car generates transverse force relative to the guide rail, only the transverse position of the guide shoe relative to the car can be adjusted. However, in practical application, it is difficult for elevator maintenance personnel to find this phenomenon in time. In most cases, when it is found that one side of the guide shoe is seriously worn, the guide shoe has been worn to an unusable state. This paper introduces an elevator guide shoe with position and lateral force monitoring function. The elevator guide shoe comprises a base fixed on the elevator car, a sliding support horizontally sliding connected with the base, a nylon block fixedly connected with the sliding support and in sliding contact with the elevator guide rail, and a displacement sensor and a force sensor arranged on the base to monitor the transverse sliding distance and transverse force between the sliding support and the base. The device has the advantages of position and transverse force monitoring function, compact overall structure, no need to change the original car layout, safety and reliability.

The Influence of Elevator Maintenance Program on Customer Satisfaction Based on Multi-Level Grey Relational Analysis

Customers are the bedrock of any business and the driving force behind its growth. As the disparities in manufacturing costs, product quality, and management systems between competing companies narrow, meeting customer expectations, increasing customer satisfaction with the company, and exceeding customer expectations has become a robust measure for businesses seeking to increase their competitiveness. While advanced manufacturing technologies or technological processes are easily replicated or even surpassed, the soft power required to gain customer satisfaction takes ongoing investigation and accumulation. This needs firms to raise their level of customer satisfaction in order to continue constructing an enterprise-specific culture that promotes enterprise development and profitability. The subject of this study is elevator maintenance customers. It employs a method known as multi-level grey relational analysis to integrate the features of customer wants in this business in order to develop an assessment system for elevator maintenance customer satisfaction. Second, collect relevant data via a customer happiness questionnaire survey of the elevator company's maintenance clients, analyze and assess the customer satisfaction data, and lastly, recommend improvement ideas based on the analysis results.

Moving target detection in elevator hoistway with millimeter-wave radar

Detection of the elevator car and counterweight is most important for the safety operation in the elevator maintenance. The purpose of this research is the development of the moving target alert system with millimeter-wave radar, which can detect the velocity and position of the moving target such as the elevator car and counterweight. In this report, we benchmarked the sensing method for detecting the moving target in the elevator hoistway and designed the moving target alert system. We developed the prototype measurement system with the 77-GHz millimeter-wave radar. Measured results of detecting the car and counterweight showed that the developed millimeter-wave radar set in the elevator pit can detect the car and the counterweight in the maintenance speed (15 m/min) and normal speed (105 m/min) within 10 m of the elevator pit.

Investigation and Improvements of the Existing Best-Value Selection Criteria for Elevator Maintenance Contractors

AbstractThe selection of appropriate maintenance contractors is essential for seamless and uninterrupted availability of elevators. Best value (BV) procurement with well-defined selection criteria ...

Preventive maintenance period decision for elevator parts based on multi-objective optimization method

Elevator maintenance plays an important role in the safe and reliable operation of elevators. However, elevator maintenance is carried under some relevant norms and standards at present, and little research has been conducted to explore how to analytically make maintenance period decision for elevator parts. In addition, the unreasonable selection of the elevator maintenance period will cause excessive cost and low equipment operation efficiency. A decision-making method for elevator parts' maintenance is provided in this paper, which aims to solve the problem of seeking a reasonable maintenance cycle for elevator parts. First of all, the historical fault data of elevator parts is used to analyze their fault distribution law. In order to accurately reflect the changes of parts after maintenance and repair, the age reduction factor and the failure rate increasing factor are introduced to establish a mixed failure rate model. Accordingly, the cost rate and utilization rate model are established under the comprehensive consideration of cost and time factors in the maintenance process. Furthermore, a multi-objective optimization model is built with maintenance frequency as the decision variable. Then, Monte Carlo simulation method is used to solve the optimization model, and the best maintenance period of the parts within the service time is obtained. Finally, the proposed method is applied to the elevator parts to find out their optimum maintenance frequency, and the results show the effectiveness of the method. A reasonable maintenance period can not only reduce the risk of equipment failure, but also save costs so as to avoid excessive waste of resources.

THE SAFETY ELEVATOR

-The main purpose of this document is to perform an analysis on elevator safety considerations. This report introduces the development of elevators through its history, definitions and commonly used concepts in the elevator industry. Elevators are already an important part of day-to-day life for thousands of people and have significant role to play in the future of urbanization due to increasing population density and decreasing real estate. Elevators not only make vertical transportation convenient, but also play an important role in providing accessibility for people with disabilities; so, it’s safe and reliable operation is very crucial. Elevator maintenance and safety practices around the country are evaluated in this article and a study on various elevator related accidents was performed to recommend safety practices. Key Words:urbanization, accessibility