scholarly journals RISK MANAGEMENT IN MAQISTRAL GAS AND OIL PIPELINE SYSTEMS WITH POTENTIAL COST CONSTRAINTS

2021 ◽  
Vol 08 (04) ◽  
pp. 59-71
Author(s):  
Oleq Dyshin, Ibrahim Habibov Oleq Dyshin, Ibrahim Habibov ◽  
Camaladdin Aslanov, Sevda Aghammadova Camaladdin Aslanov, Sevda Aghammadova
Keyword(s):  
Decision Making ◽  
Risk Management ◽  
Real Problem ◽  
Stationary Strategy ◽  
Potential Cost ◽  
Oil Pipeline ◽  
Cost Constraints ◽  
Pipeline Systems ◽  
Markov Decision ◽  
Basic Solutions

The problem of managing technical and technological risks in main gas and oil pipeline systems, subject to the possibility of limited funds allocated for the prevention and elimination of the consequences of accidents, is considered in the form of a semi-Markov decision-making model for a controlled Markov process in continuous time with the criterion of the maximum average discounted income. To find the optimal nonrandomized Markov stationary strategy, a procedure is proposed based on reducing the formulated fuzzy problem to an equivalent Boolean programming problem with deterministic constraints. To solve the resulting system of inequality constraints, an algorithm has been developed for finding basic solutions for an arbitrary number of accidents and measures to eliminate them. The numerical implementation of the proposed approach is implemented for the real problem of risk management in the main gas pipeline with unclear cost constraints. Keywords: semi-Markov decision-making process, Markov stationary strategy, feasibility optimization, basic solutions to inequalities.

Improved Methodology for Developing a Long-Range Pavement Rehabilitation Program

1997 ◽  
Vol 1568 (1) ◽  
pp. 175-185
Author(s):  
Li Wang ◽  
Michael I. Darter ◽  
Kathleen T. Hall ◽  
Yan Lu ◽  
David L. Lippert
Keyword(s):  
Decision Making ◽  
Cost Effective ◽  
Rehabilitation Program ◽  
Pavement Management ◽  
Decision Making Process ◽  
Real Problem ◽  
Potential Cost ◽  
Trade Offs ◽  
New Concepts ◽  
User Friendly

Current methodologies for developing, evaluating, and improving longrange rehabilitation programs may be classified as manual or analytical. The major limitation of manual methods is that although they are practical, they are not cost-effective because of the difficulties of comparing potential cost/benefit trade-offs among alternatives. Analytical methods, on the other hand, are more cost-effective but often not practical, because they oversimplify the real problem into a mathematical model and do not allow engineers and managers to be involved in the decision-making process. A new methodology and new concepts to overcome these major deficiencies were developed and implemented. The first of the new concepts is the use of graphical data interpretation and “visual thinking.” The second is that pavement performance evaluation should be comprehensive and quickly accessible. The third is that human knowledge should be involved in the decision-making process through a user-friendly interface. The fourth is that the relationships among the components of the methodology should be flexible rather than rigid. Finally, the process should be efficiently repeatable so that a satisfactory long-term rehabilitation program can be developed. A user-friendly, Windows-based pavement management system, called Windows ILLINET, was produced in this study on the basis of the new methodology and concepts.

Recording of the Cavitation Phenomena when Modeling Flows in the Trunk Pipelines

2020 ◽  
pp. 7-14
Author(s):  
A.M. Sverchkov ◽  
◽  
S.I. Sumskoy ◽  
Keyword(s):  
Occupational Safety ◽  
Linear Part ◽  
Simple Wave ◽  
Pressure Profile ◽  
Real Problem ◽  
Flow Modeling ◽  
Oil Pipeline ◽  
Emergency Situations ◽  
Hydraulic Shocks ◽  
The Waves

In the article, it is proposed to use a numerical method based on the approach of S.K. Godunov to simulate boiling in a pipeline. The paper presents a statement of the real problem of modeling a water hammer, considering possible boiling of the transported liquid on a real object — an oil pipeline. When solving the problem, two variants of flow modeling when closing the valve installed at the end of the pipeline were carried out. In the first Наука и техника 14 Безопасность Труда в Промышленности • Occupational Safety in Industry • № 11'2020 • www.safety.ru case, the possibility of liquid boiling was not considered. In the second case, this opportunity was considered. The performed numerical simulation showed that in the pipeline in emergency situations, liquid columns can be formed, separated by the cavitation zones and oscillating in different phases, respectively, at the collapse of the cavitation zones, which serve as a kind of pressure dampers, the collisions of liquid columns occur, which can lead, depending on the ratio of velocities, to hydraulic shocks that occur not on the valves, but on the linear part of the pipeline (local hydraulic shocks). The waves from these collapses, interacting with each other, create the new pressure peaks that do not coincide with the pattern of simple wave circulation, which are predicted in the simulations that do not consider possible liquid boiling. As a resul t, the pressures reached in the pipeline during fluid hammer is significantly different from what it would be in the absence of boiling. When boiling is considered, the maximum reached pressures are 40 % higher. Moreover, this excess is repeated. The detailed analysis of the pressure profile in the pipeline is given in the article. Based on the results of solving this problem, it is concluded that when modeling pre–emergency and emergency situations in the pipeline, it is necessary to consider the process of possible liquid boiling, since sometimes, as in the presented case, the values of the pressure surges can be higher than the values of the pressure surges in the liquid without considering boiling, which increases the likelihood of emergency depressurization.

Risk management and decision making in remediation option selection

2009 ◽  
Vol 17 (3) ◽  
pp. 345-353
Author(s):  
S. Colombano ◽  
C. Merly ◽  
H. Gaboriau
Keyword(s):  
Decision Making ◽  
Risk Management ◽  
Option Selection

scholarly journals A Qualitative Study on the US Forest Service’s Risk Management Assistance Efforts to Improve Wildfire Decision-Making

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 344
Author(s):  
Courtney A. Schultz ◽  
Lauren F. Miller ◽  
Sarah Michelle Greiner ◽  
Chad Kooistra
Keyword(s):  
Decision Making ◽  
Risk Management ◽  
Decision Support ◽  
Qualitative Study ◽  
Fire Management ◽  
Perceived Value ◽  
Forest Service ◽  
The Us ◽  
Decision Biases ◽  
Line Officers

To support improved wildfire incident decision-making, in 2017 the US Forest Service (Forest Service) implemented risk-informed tools and processes, together known as Risk Management Assistance (RMA). The Forest Service is developing tools such as RMA to improve wildfire decision-making and implements these tools in complex organizational environments. We assessed the perceived value of RMA and factors that affected its use to inform the literature on decision support for fire management. We sought to answer two questions: (1) What was the perceived value of RMA for line officers who received it?; and (2) What factors affected how RMA was received and used during wildland fire events? We conducted a qualitative study involving semi-structured interviews with decision-makers to understand the contextualized and interrelated factors that affect wildfire decision-making and the uptake of a decision-support intervention such as RMA. We used a thematic coding process to analyze our data according to our questions. RMA increased line officers’ ability to communicate the rationale underlying their decisions more clearly and transparently to their colleagues and partners. Our interviewees generally said that RMA data analytics were valuable but did not lead to changes in their decisions. Line officer personality, pre-season exposure to RMA, local political dynamics and conditions, and decision biases affected the use of RMA. Our findings reveal the complexities of embracing risk management, not only in the context of US federal fire management, but also in other similar emergency management contexts. Attention will need to be paid to existing decision biases, integration of risk management approaches in the interagency context, and the importance of knowledge brokers to connect across internal organizational groups. Our findings contribute to the literature on managing change in public organizations, specifically in emergency decision-making contexts such as fire management.

scholarly journals Optimal Policies for Quantum Markov Decision Processes

2021 ◽  
Author(s):  
Ming-Sheng Ying ◽  
Yuan Feng ◽  
Sheng-Gang Ying
Keyword(s):  
Decision Making ◽  
Reinforcement Learning ◽  
Quantum Systems ◽  
Sequential Decision Making ◽  
Mathematical Framework ◽  
Sequential Decision ◽  
Learning Techniques ◽  
Optimal Policies ◽  
Markov Decision ◽  
Programming Algorithms

AbstractMarkov decision process (MDP) offers a general framework for modelling sequential decision making where outcomes are random. In particular, it serves as a mathematical framework for reinforcement learning. This paper introduces an extension of MDP, namely quantum MDP (qMDP), that can serve as a mathematical model of decision making about quantum systems. We develop dynamic programming algorithms for policy evaluation and finding optimal policies for qMDPs in the case of finite-horizon. The results obtained in this paper provide some useful mathematical tools for reinforcement learning techniques applied to the quantum world.

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