Maintenance Costs
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2021 ◽  
Vol 24 (1) ◽  
pp. 15-24
Chao Zhang ◽  
Yadong Zhang ◽  
Hongyan Dui ◽  
Shaoping Wang ◽  
Mileta M. Tomovic

Maintenance is an important way to ensure the best performance of repairable systems. This paper considers how to reduce system maintenance cost while ensuring consistent system performance. Due to budget constraints, preventive maintenance (PM) can be done on only some of the system components. Also, different selections of components to be maintained can have markedly different effects on system performance. On the basis of the above issues, this paper proposes an importance-based maintenance priority (IBMP) model to guide the selection of PM components. Then the model is extended to find the degree of correlation between two components to be maintained and a joint importance-based maintenance priority (JIBMP) model to guide the selection of opportunistic maintenance (OM) components is proposed. Also, optimization strategies under various conditions are proposed. Finally, a case of 2H2E architecture is used to demonstrate the proposed method. The results show that generators in the 2E layout have the highest maintenance priority, which further explains the difference in the importance of each component in PM.

2021 ◽  
Nur Amalina Mohamad Zaki ◽  
Zuha Rosufila Abu Hasan ◽  
Safiek Mokhlis ◽  
Shahriman Abdul Hamid ◽  

Even prior to the COVID-19 pandemic, marketing for online conservation was increasingly used by conservationists to appeal for funds from businesses and to improve public awareness on the need to reduce the loss of biodiversity. Yet, uncertainty remains in the academic literature about the effectiveness of online conservation marketing. Given that the potential impact of online conservation marketing in the corporate sector is evident (i.e., with a clear reduction in management and maintenance costs, and an increase fund collection), knowledge of online conservation marketing is important for building and maintaining a conservation group -to-business relationship. This study serves as an exploratory inquiry and aims to understand whether Environmental Education Centers (EECs) in Malaysia use electronic platforms for conservation marketing purposes. Based on an extensive literature search on conservation marketing and a search for EEC background information, from 2015 to 2020 many EECs in Malaysia have either used, or are using (i.e., WWF Malaysia) or will soon be using (i.e., Taman Hidupan Liar Gua Musang) online conservation marketing as one of their marketing strategies. The findings hold true even for the EECs with poor Internet connections (i.e., National Elephant Conservation Centre Kuala Gandah). This exploratory study underscores the need for more research in this area, especially with regard to the effectiveness of online conservation marketing among EECs since many of the EECs are situated in locations with poor Internet connectivity. Without an understanding of electronic marketing strategy used by the EECs, the conservationists’ role will likely be limited to that of conservation research, improving the standards of animal welfare and describing the loss of biodiversity.

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2929
Olfa Kanoun ◽  
Sabrine Khriji ◽  
Slim Naifar ◽  
Sonia Bradai ◽  
Ghada Bouattour ◽  

Advanced sensors are becoming essential for modern factories, as they contribute by gathering comprehensive data about machines, processes, and human-machine interaction. They play an important role in improving manufacturing performance, in-factory logistics, predictive maintenance, supply chains, and digitalization in general. Wireless sensors and wireless sensor networks (WSNs) provide, in this context, significant advantages as they are flexible and easily deployable. They have reduced installation and maintenance costs and contributed by reducing cables and preinstalled infrastructure, leading to improved reliability. WSNs can be retrofitted in machines to provide direct information from inside the processes. Recent developments have revealed exciting possibilities to enhance energy harvesting (EH) and wireless energy transmission, enabling a reliable use of wireless sensors in smart factories. This review provides an overview of the potential of energy aware WSNs for industrial applications and shows relevant techniques for realizing a sustainable energy supply based on energy harvesting and energy transfer. The focus is on high-performance converter solutions and improvement of frequency, bandwidth, hybridization of the converters, and the newest trends towards flexible converters. We report on possibilities to reduce the energy consumption in wireless communication on the node level and on the network level, enabling boosting network efficiency and operability. Based on the existing technologies, energy aware WSNs can nowadays be realized for many applications in smart factories. It can be expected that they will play a great role in the future as an enabler for digitalization in this decisive economic sector.

Paulius Stankaitis ◽  
Alexei Iliasov ◽  
Tsutomu Kobayashi ◽  
Yamine Aït-Ameur ◽  
Fuyuki Ishikawa ◽  

AbstractThe decentralised railway signalling systems have a potential to increase capacity, availability and reduce maintenance costs of railway networks. However, given the safety-critical nature of railway signalling and the complexity of novel distributed signalling solutions, their safety should be guaranteed by using thorough system validation methods. To achieve such a high-level of safety assurance of these complex signalling systems, scenario-based testing methods are far from being sufficient despite that they are still widely used in the industry. Formal verification is an alternative approach which provides a rigorous approach to verifying complex systems and has been successfully used in the railway domain. Despite the successes, little work has been done in applying formal methods for distributed railway systems. In our research we are working towards a multifaceted formal development methodology of complex railway signalling systems. The methodology is based on the Event-B modelling language which provides an expressive modelling language, a stepwise development and a proof-based model verification. In this paper, we present the application of the methodology for the development and verification of a distributed protocol for reservation of railway sections. The main challenge of this work is developing a distributed protocol which ensures safety and liveness of the distributed railway system when message delays are allowed in the model.

2021 ◽  
Vol 0 (0) ◽  
Libor Ižvolt ◽  
Peter Dobeš

Abstract The current trend in Europe and worldwide is to support the development of so-called green transport, characterized by lower energy consumption and lower CO2 emissions. Rail transport meets these conditions and therefore considerable funding is being spent not only on the construction of high-speed lines but also on the modernization of existing railways, especially those forming part of the trans-European corridors. Three corridors of the basic TEN-T network pass through the territory of the Slovak Republic. In the Žilina Region, there are two corridors, Balt – Adriatic and Rhine – Danube, with a common section Púchov – Žilina, which is currently being modernized. It is a known fact that railway lines often show a greater degree of degradation in the transition zones between the earthwork and the structures of sub-ballast layers. Since every railway infrastructure management aims to minimize maintenance costs, while ensuring the safety and comfort of passengers, it is necessary to pay increased attention also to transiton zones. In this context, the presented paper deals with the analysis of values of deformation characteristics on the modernized line section Púchov – Považská Teplá, which is characterized by several bridge structures and tunnels. The values were obtained within the quality inspection of work in transition zones located between the earthwork and the structures of sub-ballast layers.

2021 ◽  
Vol 15 ◽  
pp. 53-60
A. Skujevska ◽  
F. Romagnoli ◽  
T. Zoss ◽  
I. Laicane ◽  
D. Blumberga

To achieve national target proposed by the Renewable Energy Source Directive 2009/28/EC, to also accomplish to the CO2 emission reduction targets and to decrease the energy dependency Latvian government is planning to adopt different strategy policies such as feed-in tariffs (FITs) and capital subsidies, in order to incentive investor to use renewable based technology for power production Neverthelss it is crucial to understand in long term perspective the effect and the costs of a specific policy (made even by the combination of different policy tools) applied to the energy sector. Using this model, or an extended version of it, a cost/benefit analysis of a different set of policy scenarios can be carried out. More in specific this study is driving its attention at a situation where it is possible to increase the share of wind power in the energy balance respect the use of natural gas as primary energy for power generation. Four political instruments are chosen in this model: subsidies for construction of new wind-power facilities, information package at all power supply levels for risk reduction and reduction of maintenance costs through a learning effect. The simulation period is from 2010 to 2110. The analysis of policy instruments for development of renewable energy resources in power system illustrates wide potential of system dynamic modelling use for statement of priorities on power diversification. The policy instrument of use of subsidies is a crucial priority. Feed-in tariff is not providing an evident. The reason of that can be related to the key aspect on the way Latvia is organizing its feed-in tariff policy.

Xiaoning Zhang ◽  
Jiajia Cai ◽  
Xufeng Zhao

This paper takes up managerial maintenance policies during different phases for mission executions. When a mission execution is divided into two phases and three phases respectively, replacement, minimal repair and keeping failure status become alternatives for managerial maintenance policies. Further, we give approximations of the above managerial maintenance policies to make the computations simple. In this paper, keeping failure status is considered as the last choice for the last phase of mission executions. We aim to minimize the expected maintenance costs for the total mission executions. All of the discussions are made analytically and their numerical examples are given.

2021 ◽  
Vol 13 (22) ◽  
pp. 12383
Praewa Wongburi ◽  
Jae K. Park

Wastewater treatment plants (WWTPs) use considerable workforces and resources to meet the regulatory limits without mistakes. The advancement of information technology allowed for collecting large amounts of data from various sources using sophisticated sensors. Due to the lack of specialized tools and knowledge, operators and engineers cannot effectively extract meaningful and valuable information from large datasets. Unfortunately, the data are often stored digitally and then underutilized. Various data analytics techniques have been developed in the past few years. The methods are efficient for analyzing vast datasets. However, there is no wholly developed study in applying these techniques to assist wastewater treatment operation. Data analytics processes can immensely transform a large dataset into informative knowledge, such as hidden information, operational problems, or even a predictive model. The use of big data analytics will allow operators to have a much clear understanding of the operational status while saving the operation and maintenance costs and reducing the human resources required. Ultimately, the method can be applied to enhance the operational performance of the wastewater treatment infrastructure.

2021 ◽  
Vol 12 (4) ◽  
pp. 232
Kai Sheng ◽  
Mahdieh Dibaj ◽  
Mohammad Akrami

While U.K. authorities have attempted to tailor measures to boost sales of electric vehicles (EVs) and support citizens through different schemes, the size and geographic coverage of the existing charging network are insufficient, which undermines electromobility promotion. There are 15,853 public charging points installed in the U.K. as of 3 August 2021, and the demands for public EV charging are rising. For rural areas, there is little support from local authorities or private companies. To identify how a charging station can be installed and work, this study researches existing charging stations nationwide. Generally, most Public Charging Stations (PCS) in rural areas have unsatisfactory cost-effectiveness due to their long payback period. This paper presents how many rural PCS are able to afford the cost in the first eight years. Based on the ever-increasing demands of the market, EV producers are switching their business strategies. Meanwhile, the rural areas may become urban with the same definition. When it comes to the analysis of cost-effectiveness, it is possible for the PCS to bring more elements into the calculation. For Capital Expenditure (CAPEX) and Operation Expenditure (OPEX), the unnecessary cost leaves more profit space, like the possibility of unplanned maintenance costs.

2021 ◽  
Vol 3 (2) ◽  
pp. 015-025
Cahyaning Kilang Permatasari

The location of tempe processing adjacent to the settlement causes problems. The resulting liquid waste makes people uncomfortable. This is presumably because the liquid waste has not been managed properly, because it is only dumped into the drainage channel. The majority of tempe industrial entrepreneurs are home industries who are not aware of creating a healthy environment by paying attention to liquid waste processing. There are many studies on technology for the tempe industrial wastewater problem, but each technology has advantages and disadvantages. It is necessary to have a system to choose the technology that suits the waste conditions. This research takes a case study in Karanganyar Regency. The Analytical Hierarchy Process (AHP) method is a method of determining priority scale that can accommodate all aspects. Furthermore, a sequence of criteria can be arranged as needed. The results of the analysis with AHP are: technology criteria 31.09%; environment 28.65%; economic 21.74% and social 18.53%. Environmental sub-criteria showed the results of the removal of ammonia 40.56%; treated water quality 30.74%; the amount of mud is 18.91% and the emission level is 9.80%. Technology sub-criteria are ease of operation 28.67%; land area requirement 28.56%; service life of 28.05% and the potential of technology in the midification of 14.72%. Economic sub-criteria with the results of operating costs 34.21%; installation cost 33.28%; maintenance costs 23.78% and HR costs 8.73%. Social sub-criteria with the results of the need for employment of 49.10%; readiness of human resources 19.33%; implementation of construction 16.74% and aesthetics 14.82%. The results of the AHP can be used as input for tempe entrepreneurs, the government and the community to improve the environmental quality of the tempe industrial wastewater. It is hoped that entrepreneurs will find it easier to determine the appropriate technology to treat the tempe industrial liquid waste.

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