scholarly journals Scheduling of Preventive Maintenance in Healthcare Buildings Using Markov Chain

2020 ◽  
Vol 10 (15) ◽  
pp. 5263
Author(s):  
Jaime González-Domínguez ◽  
Gonzalo Sánchez-Barroso ◽  
Justo García-Sanz-Calcedo
Keyword(s):  
Markov Chain ◽  
Markov Chains ◽  
Preventive Maintenance ◽  
Operating Costs ◽  
Use Of Resources ◽  
Overall Efficiency ◽  
Maintenance Policies ◽  
Reduce Emissions ◽  
The Cost ◽  
Specific Degradation

The optimization of maintenance in healthcare buildings reduces operating costs and contributes towards increasing the sustainability of the healthcare system. This paper proposes a tool to schedule preventive maintenance for healthcare centers using Markov chains. To this end, the authors analyzed 25 healthcare centers belonging to the three Healthcare Districts of Spain and built between 1985 and 2005. Markov chains proved useful in choosing the most suitable maintenance policies for each healthcare building without exceeding a specific degradation boundary, which enabled achieving an ideal maintenance frequency and reduced the use of resources. Markov chains have also proven useful in optimizing the periodicity of routine maintenance tasks, ensuring a suitable level of maintenance according to the frequency of the failures and reducing the cost and carbon footprint. The healthcare centers observed during the study managed to save more than 700 km of journeys, reduce emissions in its operations as a whole by 174.3 kg of CO2 per month and increase the overall efficiency of maintenance operations by 15%. This approach, therefore, renders it advisable to plan the maintenance of healthcare buildings.

scholarly journals The Optimal Warranty and Preventive Maintenance Policy for the Four-State System

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Ahmed F. Attia ◽  
Eman D. Abou Elela ◽  
Hany A. Hosham
Keyword(s):  
Steady State ◽  
Markov Process ◽  
Preventive Maintenance ◽  
State System ◽  
Maintenance Policy ◽  
Failure Times ◽  
Multistate System ◽  
Maintenance Policies ◽  
The Cost ◽  
Preventive Maintenance Policy

A complete view for the multistate system considering the four-state system is here introduced. The exponential distribution for failure times and repair times is considered. The steady state availability is established via the Markov process. Different warranty and preventive maintenance policies are introduced, and also the cost of these policies for the manufacturer and the buyer is evaluated.

Design Objectives and Experience With Processor Based Gas Turbine Controls

1984 ◽  
Author(s):  
Hans D. Lenz
Keyword(s):  
Control Systems ◽  
Gas Turbine ◽  
Preventive Maintenance ◽  
Operating Conditions ◽  
Operating Costs ◽  
Future Developments ◽  
Different Types ◽  
System Requirements ◽  
The Cost

This paper describes the control system requirements to reduce operating costs of gas turbine driven equipment, and the features and technologies available from up-to-date control systems to meet these requirements. Modern control systems can affect the cost of operation in the following areas: - Reduction of downtime. - Optimizing of performance during all operating conditions. - Long-term trending and failure diagnostics to maintain optimum efficiency and for preventive maintenance. Advances in electronic technology, especially microprocessors, make it possible to achieve improvements in these areas. Programming methods, an important tool in the application of this technology, are discussed. Applications of control systems are used to illustrate their effectiveness. Guidelines are presented to judge the value of different types of control systems in gas turbine and other applications and a look at future developments is presented.

scholarly journals ANALISA PERSEDIAAN MATERIAL PADA FIRE TUBE BOILER STOCK YANG OPTIMAL DENGAN MENGGUNAKAN MARKOV CHAIN

2010 ◽  
Vol 4 (2) ◽  
pp. 40
Author(s):  
Titik Noorida
Keyword(s):  
Markov Chain ◽  
Markov Chains ◽  
Production Process ◽  
Primary Material ◽  
Water Tube ◽  
The Cost

Controlling material stock becomes important problem that faced by the company because controlling it suppods production process continually. In applaying material is efforted in order getting cost of supplier more law as possible. PT. lndomaxine is one kind of company that produces tube involving two type are fre tube and water tube, in which the primary material is tube ard plat. In dealing rhe consumen needs, the company should give amount materials so that the production will be continually, and the consumer will satisfy. Having more suplies like that is caused by accepting fluctually needs, than causes less supplier optimumly and less in cost too. Based on fenomenon above, so in this research will mucstigate the methods that will be counted the number ofmaterial askhg. To determine the number of material needs decisionand to determine the cost of optimumly material, this research uses the Markov Chains method.

scholarly journals Faster quantum mixing for slowly evolving sequences of Markov chains

Quantum ◽  
2018 ◽  
Vol 2 ◽  
pp. 105 ◽  
Author(s):  
Davide Orsucci ◽  
Hans J. Briegel ◽  
Vedran Dunjko
Keyword(s):  
Machine Learning ◽  
Markov Chain ◽  
Markov Chains ◽  
Quantum Algorithms ◽  
Mixing Time ◽  
Classical Case ◽  
Special Cases ◽  
Run Time ◽  
Time Required ◽  
The Cost

Markov chain methods are remarkably successful in computational physics, machine learning, and combinatorial optimization. The cost of such methods often reduces to the mixing time, i.e., the time required to reach the steady state of the Markov chain, which scales asδ−1, the inverse of the spectral gap. It has long been conjectured that quantum computers offer nearly generic quadratic improvements for mixing problems. However, except in special cases, quantum algorithms achieve a run-time ofO(δ−1N), which introduces a costly dependence on the Markov chain sizeN,not present in the classical case. Here, we re-address the problem of mixing of Markov chains when these form a slowly evolving sequence. This setting is akin to the simulated annealing setting and is commonly encountered in physics, material sciences and machine learning. We provide a quantum memory-efficient algorithm with a run-time ofO(δ−1N4), neglecting logarithmic terms, which is an important improvement for large state spaces. Moreover, our algorithms output quantum encodings of distributions, which has advantages over classical outputs. Finally, we discuss the run-time bounds of mixing algorithms and show that, under certain assumptions, our algorithms are optimal.

scholarly journals Discrete homing problems

2013 ◽  
Vol 23 (1) ◽  
pp. 5-18
Author(s):  
Mario Lefebvre ◽  
Moussa Kounta
Keyword(s):  
Optimal Control ◽  
Markov Chain ◽  
Markov Chains ◽  
Cost Function ◽  
Discrete Time ◽  
Value Function ◽  
The Cost ◽  
The Value Function

Abstract We consider the so-called homing problem for discrete-time Markov chains. The aim is to optimally control the Markov chain until it hits a given boundary. Depending on a parameter in the cost function, the optimizer either wants to maximize or minimize the time spent by the controlled process in the continuation region. Particular problems are considered and solved explicitly. Both the optimal control and the value function are obtained

scholarly journals The post-warranty random maintenance policies for the product with random working cycles

2021 ◽  
Vol 23 (4) ◽  
pp. 726-735
Author(s):  
Lijun Shang ◽  
Haibin Wang ◽  
Cang Wu ◽  
Zhiqiang Cai
Keyword(s):  
Preventive Maintenance ◽  
Maintenance Policy ◽  
Cost Rate ◽  
Working Cycle ◽  
Maintenance Policies ◽  
Reliability Performance ◽  
The Cost

Advanced sensors and measuring technologies make it possible to monitor the product working cycle. This means the manufacturer’s warranty to ensure reliability performance can be designed by monitoring the product working cycle and the consumer’s post-warranty maintenance to sustain the post-warranty reliability can be modeled by tracking the product working cycle. However, the related works appear seldom in existing literature. In this article, we incorporate random working cycle into warranty and propose a novel warranty ensuring reliability performance of the product with random working cycles. By extending the proposed warranty to the post-warranty maintenance, besides we investigate the postwarranty random maintenance policies sustaining the post-warranty reliability, i.e., replacement last (first) with preventive maintenance (PM). The cost rate is constructed for each post-warranty random maintenance policy. Finally, sensitivity of proposed warranty and investigated polices is analyzed. We discover that replacement last (first) with PM is superior to replacement last (first).

scholarly journals Monitoring the technological processes in the wood industry in order to make them more efficient through technical overhauling

2019 ◽  
Vol 290 ◽  
pp. 02007
Author(s):  
Radu Dan Paltan ◽  
Cristina Biriş ◽  
Loredana Anne-Marie Rădulescu
Keyword(s):  
Automotive Industry ◽  
Operating Mode ◽  
Solid Wood ◽  
Production Costs ◽  
Operating Costs ◽  
Future Research ◽  
Wood Industry ◽  
Research Article ◽  
State Of Research ◽  
The Cost

Of many techniques that are used to optimize production and costs, the studies conducted within a profile company lead to our choice for testing the 6Sigma method (the most used method in the automotive industry) in view of the economic efficiency applied in the wood Industry company. This method measures how many flaws exist in a process and determines in a systematic way how to improve it by technical overhauling and eliminating or minimizing the process for efficiency. This research article aims to study the state of research on the optimization of the production process through technical overhauling for panels reconstituted from solid wood and ways to make production more efficient by cutting costs through technical overhauling. From preliminary research, we estimate that all the items founded and others that will result from further research will result in a significant decrease in production costs that are reflected in the cost of the finished product and consequently in increasing the yield of the company by maximizing its profit. At the same time it may be the basis of future research studies in the field. The easier it is to maximize profits, the lower the operating costs are and the higher recovery rate of investments are, that will result a change in the operating mode: “working smarter not harder”.

Asymptotic behaviour of sample weighted circuits representing recurrent Markov chains

1990 ◽  
Vol 27 (03) ◽  
pp. 545-556 ◽  
Author(s):  
S. Kalpazidou
Keyword(s):  
Markov Chain ◽  
Markov Chains ◽  
Asymptotic Behaviour ◽  
Probabilistic Interpretation ◽  
Stationary Markov Chain

The asymptotic behaviour of the sequence (𝒞 n (ω), wc,n (ω)/n), is studied where 𝒞 n (ω) is the class of all cycles c occurring along the trajectory ωof a recurrent strictly stationary Markov chain (ξ n ) until time n and wc,n (ω) is the number of occurrences of the cycle c until time n. The previous sequence of sample weighted classes converges almost surely to a class of directed weighted cycles (𝒞∞, ω c ) which represents uniquely the chain (ξ n ) as a circuit chain, and ω c is given a probabilistic interpretation.

scholarly journals Urban Sustainability at the Cost of Rural Unsustainability

2021 ◽  
Vol 13 (10) ◽  
pp. 5466
Author(s):  
Guangwei Huang
Keyword(s):  
Urban Sprawl ◽  
Rural Areas ◽  
Urban Sustainability ◽  
Negative Externalities ◽  
Large Cities ◽  
Rural Sustainability ◽  
Use Of Resources ◽  
The Cost ◽  
New Framework ◽  
Japan And China

Urban sustainability refers to building and maintaining cities that can continue to function without running out of resources. However, growing cities require more land and urban sprawl has transformed surrounding rural areas into urbanized settlements. Furthermore, the prosperity of large cities depends on the supply of both natural and human resources from rural areas, either nearby or remote. On the other hand, the use of resources of rural areas by cities may cause negative externalities to rural areas, affecting their sustainability. Therefore, a critical, but very much neglected issue, is how unban sustainability should be pursued without affecting rural sustainability. In this study, cases in Japan and China were analyzed from resources and population migration perspectives to provide evidence for the possibility that urban sustainability might have been pursued at the cost of rural unsustainability. It was intended to develop a better understanding of urban sustainability through the lens of externalities. Based on the analysis, a new framework for urban sustainability study was proposed, which consists of three new pillars. Namely, externality, vulnerability, and population instability.

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