Interruption Of Production Research Articles

Antimicrobial enhancement via Cerium (II)/Lanthanum (III)‐doped TiO2 for emergency leak sealing polyurea coating system

Industrial piping structures often suffer from corrosion caused by biofouling or chemical etching, which can cause immediate structural failure. Polyurea coatings, which are fabricated for emergency leak sealing, are able to form high mechanical strength coating surfaces within seconds. After its further modification via Ce/La-doped TiO2, the polyurea coating will indicate an increment in mechanical strength, chemical durability, and reduction of microbial attachment. Due to the adsorption by the Ce/La-doped TiO2 and generation of reactive oxygen species (ROS), E. coli and Pseudomonas may lose their living conditions during the progress, and planktonic bacteria cells are prevented from enriching on the surface. The Ce/La‐dopants can also improve the original photocatalytic response of nano-TiO2 to UV light and environmental temperature. These Ce/La-doped TiO2 polyurea coatings illustrate an immediate application for emergency leak sealing purposes without any production interruption and it may prolong the time intervals for the maintenance service as well.

Testing the Efficacy of Energy Harness' UVC LEDs Against E.coli Colonies at Varied Concentrations

Energy Harness Corporation (EHC), in collaboration with researchers from Florida Gulf Coast University, sought to measure how Ultraviolet-C (UV-C) light application affects the growth of bacteria. This collaboration was developed as a validation method for EHC’s newest product, the Active Airflow UV-C Fixture. UV-C wavelengths are a subset of UV light that has been identified as an ideal method for disarming virus and bacterial strains after direct exposure. As the virulent or bacterial strains absorb the UV waves, DNA/RNA dimers which link the nucleotide chains together become damaged. This results in the interruption of DNA replication and cell production, a process known as inactivation [1]. Amidst the outbreak of SARS-CoV-2, several applications of UV-C have been explored to reduce the rate of infection of various pathogens. Using UV-C light emitting diodes (LEDs) found in EHC’s Active Airflow structure, this research demonstrates the impact of UV-C application to colonies of Escherichia coli (E. coli) plated at different concentrations. The LEDs were applied to the E. coli plated dishes at various time points at a set distance of 2 cm to determine where the greatest rate of disinfection occurred. The ideal dosages, intensities, and distances of UV-C application required to optimize the effectiveness of this concept design were determined over three trials.

Numerical Simulations in Support of a Long-Term Test of Gas Production from Hydrate Accumulations on the Alaska North Slope: Reservoir Response to Interruptions of Production (Shut-Ins)

Numerical Simulations in Support of a Long-Term Test of Gas Production from Hydrate Accumulations on the Alaska North Slope: Reservoir Response to Interruptions of Production (Shut-Ins)

Autoimmune pulmonary alveolar proteinosis in children.

In childhood, a multitude of causes lead to pulmonary alveolar proteinosis (PAP), an excessive surfactant accumulation in the alveolar space, limiting gas exchange. Autoantibodies against granulocyte–macrophage colony-stimulating factor (GM-CSF) causing autoimmune PAP, the principal aetiology in adults, are rare.In this first case series on autoimmune PAP, we detail the presentation and management issues of four children.Whereas three children presented insidiously with progressive dyspnoea, one was acutely sick with suspected pneumonia. During management, one patient was hospitalised with coronavirus disease 2019, noninvasively ventilated, and recovered. All treatment modalities known from adults including whole-lung lavage, augmentation of GM-CSF by inhaled GM-CSF, removal of neutralising antibody by plasmapheresis and interruption of antibody production using rituximab were considered; however, not all options were available at all sites. Inhaled GM-CSF appeared to be a noninvasive and comfortable therapeutic approach.The management with best benefit-to-harm ratio in autoimmune PAP is unknown and specialised physicians must select the least invasive and most effective treatment. To collect this cohort in a rare condition became feasible as patients were submitted to an appropriate registry. To accelerate the authorisation of novel treatments for autoimmune PAP, competent authorities should grant an inclusion of adolescents into trials in adults.

A machine learning-based predictive model for real-time monitoring of flowing bottom-hole pressure of gas wells

Prediction of the flowing bottom hole pressure (FBHP) of gas–water two-phase flows is of great importance in optimising the production of gas and reducing down-time in unconventional gas wells. Unlike the case for conventional gas wells, prediction of FBHP for unconventional gas wells, particularly coal seam gas (CSG) wells, has not been studied.Monitoring of FBHP typically is done using a downhole pressure sensor placed close to the bottom of the well. Replacing a failed pressure sensor or recalibration of a pressure gauge, which is required frequently throughout the life of a well for reliable measurement of FBHP, requires interruption of the gas production at a high cost. A low-cost and reliable model for continuous prediction of FBHP, would enable smooth operation of CSG wells in the event a pressure gauge fails, without interrupting the well production.This work presents predictive models for real-time and reliable prediction of FBHP using surface and subsurface data, acquired from 91 CSG wells in Australia over 5–19 month production periods. Two sets of models are developed; one for specific wells using data from that individual well and another one for a group of wells. Three different modelling approaches, multiple linear regression, linear mixed-effects and gradient boosting regression tree (XGBoost) are implemented. The XGBoost modelling outcomes show promising results with the best mean absolute percentage error (MAPE) of 10% and 11.7% for specific well models and multiple well models, respectively.

Simulating the Efficiency of Electromagnetic Pigging in Pipelines and Production Tubing Aided by Nanopaint

SummaryWax and hydrates deposition is a major concern for hydrocarbon transport in pipelines, production tubing, and other pipes in cold environments. Traditionally, chemical, mechanical, and thermal methods are used to mitigate the deposition at the expense of production interruption, complex maintenance, costs, and environmental hazards, and many of these methods are not feasible in deep water environments.This paper studies the potential of nanopaint-aided electromagnetic pigging. This process has potentially low production impact, simple maintenance, low energy cost, and no chemical expense or hazards. The electromagnetic pig contains an induction coil that emits an alternating magnetic field. The alternating magnetic field induces heat in the nanopaint coating (i.e., coating with embedded paramagnetic nanoparticles) on the pipeline’s inner wall and in the pipeline wall itself. The heat then melts and peels off the wax and hydrates adhering to the pipeline, allowing the hydrocarbon to carry them away. Without loss of generality, we focus on wax remediation in this paper.We analyze the heating effectiveness and efficiency of electromagnetic pigging. The heating effectiveness is measured by the maximum pigging speed that allows deposit removal. The heating efficiency is measured by the ratio of the heat received by the wax over the total emitted electromagnetic energy, which we define as the pig induction factor (PIF).An axisymmetric transient model is built to study the heat transfer without considering phase change. Based on our numerical model, we compare the PIF for different coil designs, different hydrocarbon flow rates, and different pig traveling speeds. We reevaluate the maximum pig speed defined by the static pig model from our previous work and found the electromagnetic pigging system is much more effective than previously estimated, while we confirm that a solenoid with larger radius allows higher pig speed. We find that faster pig speed generally improves the efficiency but decreases effectiveness and that shorter solenoids with larger radius have higher efficiency. The hydrocarbon flow rate does not impact the heating process if the wax is thicker than the threshold wax thickness. Based on the simulation results, the field application is discussed.

Features of labor activity during a pandemic and its impact on the economy in Ukraine

The COVID-19 pandemic has significantly altered the way the global labor market works. Labor activity during the pandemic is increasingly moving into the field of digitalization and electronic lifestyles. This trend has led to significant changes in the quality of the population’s life, as well as in the economic activities of manufacturers and sellers. This demonstrates the need for a more detailed study of trends in the development of the labor market and potential changes in the employment of labor resources.
 Some of the main structural components affecting the state of the country’s economy in a pandemic are highlighted. For the analysis, this includes the level of employment and the change in the profile of labor resources, as well as the income and losses of the country’s enterprises, and the GDP dynamics.
 This choice is due to the fact that labor resources are the productive force of the enterprise, which affects the efficiency of activities and profitability. In the existing conditions, the search for opportunities to improve the current order of labor organization is becoming relevant.
 The purpose of the article is to determine the main trends in the development of the Ukrainian economy, taking into account the negative impact of the pandemic, to identify the dynamics in the composition of the country’s labor resources, and to propose possible ways to reduce the negative consequences of lockdowns and production interruptions. The factor of profitability of the production spheres, which determines the socio-economic development of the state, is also considered. Depending on this factor, disproportions are formed at the levels of socio-economic development.
 Based on the data of state statistics and using the methods of empirical and mathematical research, the analysis of the dynamics of the main indicators has been carried out. Based on the data obtained on the sphere of work and financial performance of enterprises for 2020, an economic diagnostics of their unprofitableness was carried out. The method of horizontal and vertical analysis revealed a decrease in the employed population of the country, an increase in the unemployment rate, and a decrease in GDP. Calculations of the dynamics and structure of incomes and losses of Ukrainian enterprises made it possible to identify the most unprofitable sectors of the economy.
 In most cases, a change in the organization of work leads to the adaptation of the activities of the enterprise, taking into account certain conditions. The transfer of part of the workforce to work using remote methods allows not to stop production and support the country’s economy with the introduction of quarantine (lockdown). This serves as an adequate alternative compared to the prospect of dismissal of workers, which will affect not only the financial security of the population, but also the profitability of production spheres.
 In a pandemic, filling the budget is extremely important. This will allow funding to support entrepreneurship, vaccinations and social security for most of the population. Digitalization and remote work are a promising area that will take a significant place in the organization of work in the future.
 The main task of the state should be to create algorithms and standards for the social protection of people, as well as state support of enterprises.

Interference-adjusted power learning curve model with forgetting

Researchers in production and operations management have studied the effect of worker learning and forgetting on system performance for decades. It remains an active research topic. Those studies have assumed that production interruptions (or production breaks) cause forgetting, which deteriorates performance. Research on human working memory provides enough evidence that continuous forgetting, precisely cognitive interference, results from overloading the memory with information. Despite the evidence, few studies have incorporated it into learning curve models. This paper presents an enhanced version of the power learning curve that accounts for a variable degree of interference when moving from a production cycle to the next. It adopts the concept of memory trace decay to measure the residual (interference-adjusted), not the nominal (maximum) cumulative experience. We test the developed model against learning data from manual assembly and inspection tasks, with varying numbers of repetitions and breaks. We also test three alternative power-form learning and forgetting curve models from the literature. The results show that the interference-adjusted model fits the data very well. The proposed learning and forgetting model and its individualized cumulative metrics can help identify struggling workers early and release precocious learners earlier than expected. As such, the model gives insights for managers on the occurrence of interference to enable individual learning support.

Research on diagnosis method of series arc fault of three-phase load based on SSA-ELM

Arc fault in the three-phase load circuit may cause fire, resulting in production interruption and even worse, it will cause casualties. In order to effectively detect the arc fault in the three-phase circuit, series arc fault experiments of three-phase motor load and frequency converter were carried out under different current conditions. Firstly, variational mode decomposition (VMD) was performed for each cycle of A-phase current, and then the VMD energy entropy and sample entropy were calculated. Secondly, the noise-dominated component was removed according to the permutation entropy, then the average value after first-order difference of the half-cycle reconstructed signal was obtained. An arc fault diagnosis model of extreme learning machine (ELM) optimized by sparrow search algorithm (SSA) was established. The feature vectors were divided into training group and test group to train the model and test its fault diagnosis accuracy. Compared with GA-ELM, PSO-ELM, support vector machine (SVM) and SSA-SVM, the experimental results show that the proposed method can identify the series arc fault accurately and more quickly.

Identification and evaluation of human errors of Epoxy control room operators of a pipe Mill company using HEC technique

Introduction: In many workplaces today, the incidence of human error can lead to catastrophic accidents in which human error is the main cause of accidents. Due to the vital role of the control room in guiding and controlling various sites of the pipe industry, especially the outer coating sector, the incidence of any error can lead to human accidents, damage to machinery, interruption in production. This study aimed to identify and evaluate human error by Human Error Calculator (HEC) method in the epoxy control room of a pipe mill company. Materials and Methods: In the present descriptive cross-sectional study, the HEC method was used to identify and evaluate human errors. The HEC technique is provided by Risk Map Company, in which the probability of human error is based on five factors affecting the occurrence of human error, including a degree of urgency, complexity, importance, degree of individual skill, and task repetition, using a disk-shaped tool called Risk Disk is determined through direct observation, available instructions and interview with the head of the mentioned unit. Results: According to the results of this study, out of 11 identified tasks, five job tasks with a risk number of 70% have a high probability of human error, four job tasks with a risk number of 50%, and one job task with a number There is a 40% risk of moderate human error, And a job task with a 20% risk number has an increased chance of human error. Conclusion: The results of the present study showed that the HEC method is easy to use and is a simple and useful tool for professionals to calculate the probability of human error. In addition, HEC is a practical, effective and beneficial method for managers to reduce human error.

Wear resistance performance of sheet metal die materials: a review

The high and ultra-high strength steel materials are widely used in sheet metal forming processes such as stamping, bending, piercing, etc. in the automotive industry. Because of a strong adhesive propensity between the tool and the surface, the wear of the tool is created. The wear of the tool affects the dimensional property of the products, problems of surface quality and consequently interruptions of production. The wear behaviour and wear mechanisms of sheet metal dies were studied in this paper. This paper focuses on recent developments in tribological tool wear and provides adequate data on tool wear features.

Challenges and opportunities: impacts of COVID-19 on Norwegian seafood exports

A rapidly growing literature shows that COVID-19 and the measures to contain the spread of the virus can have significant market impacts for seafood. These can be interruptions of production, or reductions in demand directly or indirectly due to supply chain challenges. In this paper we investigate the potential impacts of COVID-19 on seafood exports from Norway, the world's second largest seafood exporter, using highly detailed data from 2016 through May 2021. These data allow us to assess upstream impacts in the seafood supply chain close to the producer level in aggregate and by main sector, impacts on the largest products, and the extent to which export firm structure and export markets served have changed. We find very few impacts in aggregate as well as for individual products, suggesting that the markets and supply chains used by Norwegian seafood exports were sufficiently robust and flexible to accommodate the shocks created by COVID-19. Given Norway's size as a seafood exporter, the impact of COVID-19 has likely been moderate upstreams for a number of seafood sectors around the world, especially those in wealthy nations, with opportunities balancing out challenges, and that the supply chains have been highly resilient.

Порівняльна характеристика ризик-орієнтованих фінансових стратегій компаній на міжнародному ринку в умовах війни

The article is aimed at comparing existing risk-oriented financial strategies and developing recommendations for their implementation in the activities of Ukrainian companies focused on international markets, especially under conditions of martial law. The article is devoted to the analysis of modern approaches to determining risks and their implementation in the financial strategy. It is proved that modern enterprises, especially those operating in the international market, are focused on the constant updating of the financial strategy in accordance with the requirements of the external environment. It is found that at the present stage of economic development, companies, in particular international ones, operate in the conditions of the sixth technological structure of the economy. The processes of economic development at this stage are associated with the introduction of technological, organizational and institutional innovations, paying special attention from science and management practice to the implementation of a risk-oriented approach, even for enterprises engaged in the production of consumer goods. Today, the implementation of risk management best practices is directed towards improving the management’s ability to predict and respond to changes so that the company not only survives in conditions of uncertainty, but develops and shows better results. The main risks of the development of modern companies are specified, among which are: the risk of interruptions in production; risk of cyber incidents; risk of natural disasters; risk of amendments to legislation and public policy; risk of changes in the market situation; risk of new competitors entering the market; risk of new technologies; risk of climate change; risk of reputational damage or a decrease in brand value; risk of a shortage of skilled labor force. It is proved that taking into account these risks in the development of a financial strategy is a necessary condition for the stable development of the company. The advantages and disadvantages of each of the risk-oriented financial strategies of international companies proposed in the article are systematized as follows: concentrated growth; integrated growth; diversified growth; differentiation; minimum costs; development. It is determined that for modern enterprises operating in a turbulent external environment, but at the same time promoting their products to world markets and hoping to more actively explore new markets, it is extremely important to choose the optimal financial strategy that would take into account the risks. Precisely for this purpose, the existing financial strategies are systematized in the publication and it is proved that the application of these strategies in the context of risk orientation can increase the efficiency of enterprise development in the international market.

The Value of Lost Load in Swedish Industry

The power system is undergoing a drastic transition towards a system with high degree of intermittency at the same time as the transition in other sectors will require more electricity. Taken together this will make it more challenging to keep the instantaneous balance between demand and supply in the power market with increasing risks of interruptions and power outages as a result. The objective of this study is to estimate the cost of power outages in the Swedish industrial sector by using firm- level, production data. Our estimates of interruption costs are based on firms’ actual behavior concerning their use of electricity and the values created. The main approach is complemented with a qualitative study based on a questionnaire targeting key-persons in a small number of industrial production facilities. The purpose with this is to identify firm or facility specific aspects that that are not revealed by annual firm level data. The main conclusion from this study is that the costs for the industry of supply interruptions are considerable, and seems to have increased over time, suggesting that the industrial sector has become more vulnerable to supply disturbances. In 2016 the estimated cost of a one-hour outage for an average industrial facility in Sweden was approximately 23 times larger than the value of the electricity not delivered (SEK 9502 versus SEK 400), whereas the cost in 2004 was approximately 13 times the market value of the electricity not delivered. However, there is substantial variation across firms and sectors. For an average facility in the electro and motor vehicle industry, for example, a one-hour cost is, according to our estimates, about 120 and 105 times the market value of the electricity not delivered, respectively (SEK 43680 versus SEK 415 for an average motor vehicle firm). In the pulp and paper industry, on the other hand, the outage cost is only about 5 times the value of undelivered electricity in spite of a relatively high outage cost in absolute value (SEK 27730). The reason for the relative low ratio for the pulp and paper industry is the very high level of electricity intensity. The estimated costs should however be interpreted with care since they are based on the assumption that the interruption in production processes corresponds exactly to the duration of the outage, but also that the production losses during the outage are lost forever and cannot be compensated for in any way. Importantly, according to the results from our survey most firms or production facilities reported that the production interruption becomes noticeable longer than the power outage itself. In addition, most of them reported additional costs because of an outage, such as costs for overtime and delivery delays. On the other hand, several facilities firms reported that they may be able to “take back” the production losses during a year. Altogether, the first effects seem to dominate according to the survey results and the cost estimates reported should therefore be interpreted as lower bounds.

Detekcija uzroka pucanja cevi na zagrejaču vode procesnog CO parnog kotla

In this paper results of analysis of process steam boiler operation with maximum continuous steam production of 75 t/h, steam pressure and temperature of 45,5 bar and 412 oC are presented. Steam boiler is predicted to operate within steam production facility of oil and gas refinery in Pančevo, Serbia. On the demand of purchaser steam boiler is enabled to operate with various fuels as well as with two or three fuels simultaneously. By fuels intake facilities it is enabled to introduce refinery gas, fuel oil and high-temperature waste gas to the boilers furnace. Waste gas is guided from FCC (Fuel catalyst cracking) facility and presents two-component fluid with polydisperse solid phase composed of particles of diameter smaller than 40 µm. Recent changes in steam consumption in refinery resulted in modifications in boiler`s operating regime and, further on, in significant changes in its operational parameters. At present, in new conditions, boiler operates with frequent pipe bursts on pipe bundles of boiler economizer which requires forced interruption in steam production as well as time and cost consuming operations for resuming boiler work. In this paper results of thermal calculations for design and new operational conditions are presented for the purpose of identification of cause of frequent unscheduled steam production interruptions. After analysis of presented results, recommendations on how to modify certain boiler operational parameters in order to eliminate or reduce possibility of such unfavourable occurance has been provided.

The Pathology of Infectious Bronchitis.

Infectious bronchitis (IB) is an acute disease of chickens caused by a gammacoronavirus, infectious bronchitis virus (IBV). Infection of the nasal and tracheal mucosa causes a rapid loss of ciliated epithelium and impaired mucociliary clearance that predispose chickens to secondary bacterial infections. In poultry production, disease progression and severity are influenced by other live virus vaccines, immunosuppression, and coexisting pathogens. The digestive tract supports viral replication in the proventriculus, intestines, cloaca, and the bursa of Fabricius. Acute enteritis and stunted growth in young chickens are caused by an enterotropic IBV. IBV spreads systemically by infection of tracheal macrophages and blood monocytes, deep respiratory infections, and potentially ascending viral infection from the cloaca. Nephrotropic IBV causes severe disease in the kidney with necrosis of tubular epithelial cells, inflammation, and renal failure. Viral infection of the female reproductive tract in the first 2 weeks of life causes necrosis and scarring of the oviduct mucosa, resulting in a chronic cystic oviduct that precludes egg formation when the hen matures. Virus infection of mature hens causes necrosis and inflammation of the oviduct mucosa, leading to the deterioration of egg quality and transient interruption of egg production. In males, IBV infection of seminiferous tubules in the testicle and efferent ductules in the epididymis results in epididymitis and epididymal lithiasis, decreases in sperm production and fertility, and viral shed to semen, leading to venereal transmission. The role IBV in gastrointestinal and urogenital disease merits further study.

A multiphase acceptance sampling model by attributes to investigate the production interruptions in batch production within tobacco industry

PurposeThis paper aims to create a new decision-making procedure that uses “Lot-by-Lot Acceptance Sampling Plan by Attributes” methodology in the production processes when any production interruption is observed in tobacco industry, which is a significant example of batch production.Design/methodology/approachBased on the fish bone diagram, the reasons of the production interruptions are categorized, then Lot-by-Lot Acceptance Sampling Plan by Attributes is studied to overcome the reasons of the production interruptions. Furthermore, managerial aspects of decision making are not ignored and hence, acceptance sampling models are determined by an Analytical Hierarchy Process (AHP) among the alternative acceptance sampling models.FindingsA three-phased acceptance sampling model is generated for determination of the reasons of production interruptions. Hence, the necessary actions are provided according to the results of the proposed acceptance sampling model. Initially, 729 alternative acceptance sampling models are found and 38 of them are chosen by relaxation. Then, five acceptance sampling models are determined by AHP.Practical implicationsThe current experience dependent decision mechanism is suggested to be replaced by the proposed acceptance sampling model which is based on both statistical and managerial decision-making procedure.Originality/valueAcceptance sampling plans are considered as a decision-making procedure for various cases in production processes. However, to the best of our knowledge Lot-by-Lot Acceptance Sampling Plan by Attributes has not been considered as a decision-making procedure for batch production when any production interruption is investigated.

Field test investigation of the performance of corrosion inhibitors: a case study

Corrosion is considered one of the major problems that affect flow assurance during hydrocarbon production. This irreversible phenomenon has the ability to cause serious material failure in the oil and gas industry. Consequently, heavy capital and operational costs are required to prevent corrosion processes. Sweet corrosion of raw gas production facilities in an Algerian gas field manifests inside surface installations, which leads to gas production interruption and high intervention costs. To mitigate this type of corrosion, many methods can be applied such as the selection of appropriate materials, the injection of inhibitors, and the use of protective coating. In this work, the main points of gas production system that have been affected by corrosion and the inspection techniques used in the studied field were reviewed. Moreover, the efficiency of two types of two corrosion inhibitors (film-forming/neutralizing and film-forming chemicals) was studied by measuring the corrosion rate in the field and conducting chemical analyses on the produced water samples in the laboratory. The results of laboratory analyses regarding pH and iron content measurement point out that the injection of film-forming/neutralizing chemical significantly shifted the pH of the medium from acid to more neutral value and decreased the iron content, while the injection of film-forming inhibitor affected only the iron content by decreasing its tenor in the water samples. These results confirm the functions of each inhibitor to protect metal against internal corrosion. The comparison between the single- and double-function inhibitors reveals that the film-forming inhibitor (CK981DZ) outperforms the film-forming/ neutralizing chemical with an efficiency that exceeds 99% at low injection rate. Moreover, it provides good compatibility and stability all through its injection path. Meanwhile, the application of double function inhibitor (film-forming/neutralizing) significantly reduced the corrosion rate of carbon steel structures, but it involved the formation of deposits in the gas processing plant. The findings from this study can help give a better understanding of the methodology of corrosion inhibitor performance evaluation in real condition of gas production, also the criteria of inhibitor screening based on laboratory and field tests.

Towards application of machine learning algorithms for prediction temperature distribution within CFB boiler based on specified operating conditions

The availability of the power unit for electricity production is one of the most important issues of the power plant operator. Considering the power unit, boiler is the main source of its malfunction. Depending of the boiler construction, source of problem can be different. In case of usage of the circulating fluidized bed boiler the potential issue that can lead to interruption of the energy production is its failure caused by leakages of heating surfaces. In order to mitigate this risk different treatments or procedures are introduced. Nowadays, thanks to continuous development of mathematical tools its is possible to introduce a new solution to reduce the risk of heating surface erosion cause by the friction of solid material used in fluidization. One of possible option, that can help to resolve such a problem is application of machine learning technique. Based on real observation of the boiler operation and data analysis, it is believed that the uniform temperature distribution at the lower part of the combustion chamber should has positive impact on erosion reduction at the kick-out level where tapered walls changed to vertical one. This can be attain by careful manipulation of selected boiler operating parameters. Due to the reason that in order to find requires setup dozen of input data configuration need to be considered appropriate toll need to be developed. That is the main reason way the machine learning technique need to be applied for such purpose. Indeed, of this work is to develop artificial models that can help in adjustment boiler setup. In order to check models functionality, they were on-site tested by boiler operator. Developed model shows tremendous potential and confirm that it is worth to investigated this topic farther.

A New Multiobjective Time-Cost Trade-Off for Scheduling Maintenance Problem in a Series-Parallel System

In this paper, a modified model of Nondominated Sorting Genetic Algorithm 2 (NSGA-II), which is one of the Multiobjective Evolutionary Algorithms, is proposed. This algorithm is a new model designed to make a trade-off between minimizing the cost of preventive maintenance (PM) and minimizing the time taken to perform this maintenance for a series-parallel system. In this model, the limitations of labor and equipment of the maintenance team and the effects of maintenance issues on manufacturing problems are also considered. In the mathematical model, finding the appropriate objective functions for the maintenance scheduling problem requires all maintenance costs and failure rates to be integrated. Additionally, the effects of production interruption during preventive maintenance are added to objective functions. Furthermore, to make a better performance compared with a regular NSGA-II algorithm, we proposed a modified algorithm with a repository to keep more unacceptable solutions. These solutions can be modified and changed with the proposed mutation algorithm to acceptable solutions. In this algorithm, modified operators, such as simulated binary crossover and polynomial mutation, will improve the algorithm to generate convergence and uniformly distributed solutions with more diverse solutions. Finally, by comparing the experimental solutions with the solutions of two Strength Pareto Evolutionary Algorithm 2 (SPEA2) and regular NSGA-II, MNSGA-II generates more efficient and uniform solutions than the other two algorithms.