Proposing an Optimum Model for Time Estimation of Construction Projects in Iranian Gas Refineries

Time management can be effective in a project when the project schedule is based on comprehensive time scheduling. In the industries with complicated processes, many uncertainties and risks affect the timing of projects. Considering the very low reliability of the project planning in certainty-based approach, using more secure models for control and interact with uncertainty should be placed on the agenda. Iranian Gas Company has been using risk management to manage probable uncertainties in construction projects but in the field of possible uncertainties, actions are very scarce. This article aims to propose an optimum model based on the integrated risk management and fuzzy expert systems in order to provide comprehensive project time estimation and in this regard, reviews the results of the implementation of this model in construction projects of Iranian gas refineries. The results show that the proposed model increases the accuracy of time estimation about 8 to 24 percent.Time management can be effective in a project when the project schedule is based on comprehensive time scheduling. In the industries with complicated processes, many uncertainties and risks affect the timing of projects. Considering the very low reliability of the project planning in certainty-based approach, using more secure models for control and interact with uncertainty should be placed on the agenda. Iranian Gas Company has been using risk management to manage probable uncertainties in construction projects but in the field of possible uncertainties, actions are very scarce. This article aims to propose an optimum model based on the integrated risk management and fuzzy expert systems in order to provide comprehensive project time estimation and in this regard, reviews the results of the implementation of this model in construction projects of Iranian gas refineries. The results show that the proposed model increases the accuracy of time estimation about 8 to 24 percent

Presenting a Model Based on Fuzzy Application to Optimize the Time of IBS Projects in Gas Refineries

Nowadays, the construction industry has started to embrace IBS as a method of attaining better construction quality and productivity and reducing risks related to occupational safety and health. The built of pre-fabricated component in factories reduces many problems related to lack of purposing uncertainty in scheduling calculation and time management of projects. In the case of using IBS method for managing time in projects, former studies such as Allan Tay’s research, indicates that this method can save up at least 29% of overall completion period versus the conventional method. But beside mentioned advantages of this technical method, the projects could be optimized more and more in scheduling calculations. This issue is critical in gas refineries, since special parameters such as risk of spreading poison H2S gas and mandatory of performing projects in short time period events such as maintenance overhauls demands to perform projects in optimum time. Custom scheduling calculation of project planning uses the Critical Path Method (CPM) as a tool for Planning Project’s activities. The researches of this paper’s authors indicated that Fuzzy Critical Path Method (FCPM) is the best technique to manage the uncertainty in project scheduling and can save up the construction project’s time versus the custom methods. This paper aims to present a model based on fuzzy application in CPM calculations to optimize the time of Industrial Building System

Presenting a Model Based on Fuzzy Application to Optimize the Time of IBS Projects in Gas Refineries

Nowadays, the construction industry has started to embrace IBS as a method of attaining better construction quality and productivity and reducing risks related to occupational safety and health. The built of pre-fabricated component in factories reduces many problems related to lack of purposing uncertainty in scheduling calculation and time management of projects. In the case of using IBS method for managing time in projects, former studies such as Allan Tay’s research, indicates that this method can save up at least 29% of overall completion period versus the conventional method. But beside mentioned advantages of this technical method, the projects could be optimized more and more in scheduling calculations. This issue is critical in gas refineries, since special parameters such as risk of spreading poison H2S gas and mandatory of performing projects in short time period events such as maintenance overhauls demands to perform projects in optimum time. Custom scheduling calculation of project planning uses the Critical Path Method (CPM) as a tool for Planning Project’s activities. The researches of this paper’s authors indicated that Fuzzy Critical Path Method (FCPM) is the best technique to manage the uncertainty in project scheduling and can save up the construction project’s time versus the custom methods. This paper aims to present a model based on fuzzy application in CPM calculations to optimize the time of Industrial Building System

Viral Diseases in Potato

Viruses are among the most significant biotic constraints in potato production. In the century since the discovery of the first potato viruses we have learned more and more about these pathogens, and this has accelerated over the last decade with the advent of high-throughput sequencing in the study of plant virology. Most reviews of potato viruses have focused on temperate potato production systems of Europe and North America. However, potato production is rapidly expanding in tropical and subtropical agro-ecologies of the world in Asia and Africa, which present a unique set of problems for the crop and affect the way viruses can be managed. In this chapter we review the latest discoveries in potato virology as well as the changes in virus populations that have occurred over the last 50 years, with a particular focus on countries in the (sub-)tropics. We also review the different management approaches including use of resistance, seed systems, and cultural approaches that have been employed in different countries and reflect on what can be learnt from past research on potato viruses, and what can be expected in the future facing climate change. © The Editor(s) (if applicable) and The Author(s) 2020.Peer reviewe