scholarly journals Optimization of pipeline lifecycle cost using alternatives with different life spans

2021 ◽  
Author(s):  
Ibrahim H. Elsebaie ◽  
Abdulrahman Al-Khomairi
Keyword(s):  
Optimization Approach ◽  
Pipe Material ◽  
Surge Tank ◽  
Design Alternatives ◽  
Decision Variables ◽  
Optimum Diameter ◽  
Pipeline Project ◽  
Project Optimization ◽  
Total Project Cost ◽  
Total Project

Abstract This paper suggests a pipeline project optimization approach that compares alternatives with different life spans. The average inflation rate is used to project the future maintenance, operation and replacement costs. The average interest rate is used to express all the costs in Equivalent Real Annual Cost (ERAC), which is the correct cost form to compare alternatives with different life spans. The pipe diameter, material, pressure rating, surge tank size, and inlet/outlet resistances are the decision variables. A software was compiled with a commercial pipeline software to generate all the possible design alternatives based on the decision variables. Pipe initial cost as well as operation and maintenance costs are computed for each design alternative. The alternative with the least ERAC value is the optimum one. It was found that the approach can lead to substantial savings in pipelines projects cost. For pipes 800 mm in diameter or larger, and when selecting the optimum diameter, savings are between 23 and 27% in the total project cost. When imposing certain pipe material savings in overall cost will be 8.5, 16.3 and 31.3% for ductile iron, GRP and mild steel pipe material, respectively.

scholarly journals Comprehensive optimization of project cost for long supply pipelines

2021 ◽  
Vol 9 (3A) ◽  
Author(s):  
Abdulrahman Al-Khomairi ◽  
◽  
BongSeog Jung ◽  
Keyword(s):  
Interest Rates ◽  
Optimization Procedure ◽  
Optimization Approach ◽  
Protection Device ◽  
Surge Tank ◽  
Operational Costs ◽  
Design Alternatives ◽  
Wide Range ◽  
The One ◽  
Pipeline Design

This paper proposes a “comprehensive” pipeline design optimization approach that considers pipe parameters, protection device parameters, and project maintenance and operational costs over the pipeline’s service life. The objective is to search for an optimal pipeline design by analyzing alternatives with different lifespans, while taking inflation and interest rates into account. A specially designed genetic algorithm routine suggests possible solutions that encompass a range of available pipe diameters, pipe materials, pipe pressure ratings, surge tank sizes, and inlet/ outlet resistances. With both steady-state and unsteady pipe flow analyses, the solution provides a system satisfying required demand without violating velocity and pressure constraints. A real-world project is selected to investigate the outcome of the optimization procedure. The proposed comprehensive optimization approach is shown to be an effective method of comparing a wide range of design alternatives for pipeline projects and identifying the one that optimizes the overall cost.

Innovative Hybrid Genetic Algorithms and Line Search Method for Industrial Production Management

2010 ◽  
pp. 142-160 ◽  
Author(s):  
Pandian M. Vasant
Keyword(s):  
Production Management ◽  
Optimization Problems ◽  
Fuzzy Optimization ◽  
Computational Techniques ◽  
Optimization Approach ◽  
Non Linear Programming ◽  
Decision Variables ◽  
Line Search Method ◽  
Non Linear ◽  
Management Optimization

Many engineering, science, information technology and management optimization problems can be considered as non linear programming real world problems where the all or some of the parameters and variables involved are uncertain in nature. These can only be quantified using intelligent computational techniques such as evolutionary computation and fuzzy logic. The main objective of this research chapter is to solve non linear fuzzy optimization problem where the technological coefficient in the constraints involved are fuzzy numbers which was represented by logistic membership functions by using hybrid evolutionary optimization approach. To explore the applicability of the present study a numerical example is considered to determine the production planning for the decision variables and profit of the company.

scholarly journals Qom—A New Hydrologic Prediction Model Enhanced with Multi-Objective Optimization

2019 ◽  
Vol 10 (1) ◽  
pp. 251 ◽  
Author(s):  
Gustavo R. Zavala ◽  
José García-Nieto ◽  
Antonio J. Nebro
Keyword(s):  
River Basins ◽  
Hydrologic Model ◽  
Optimization Approach ◽  
Prediction Errors ◽  
Efficiency Coefficient ◽  
Multi Objective Optimization ◽  
Hydrologic Models ◽  
Multi Objective ◽  
Decision Variables ◽  
Hydrologic Prediction

The efficient calibration of hydrologic models allows experts to evaluate past events in river basins, as well as to describe new scenarios and predict possible future floodings. A difficulty in this context is the need to adjust a large number of parameters in the model to reduce prediction errors. In this work, we address this issue with two complementary contributions. First, we propose a new lumped rainfall-runoff hydrologic model—called Qom—which is featured by a limited set of continuous decision variables associated with soil moisture and direct runoff. Qom allows to separate and quantify the volume of losses and excesses of the rainwater falling in a hydrographic basin, while a Clark’s model is used to determine output hydrograms. Second, we apply a multi-objective optimization approach to find accurate calibrations of the model in a systematic and automatic way. The idea is to formulate the process as a bi-objective optimization problem where the Nash-Sutcliffe Efficiency coefficient and percent bias have to be minimized, and to combine the results found by a set of metaheuristics used to solve it. For validation purposes, we apply our proposal in six hydrographic scenarios, comprising river basins located in Spain, USA, Brazil and Argentina. The proposed approach is shown to minimize prediction errors of simulated streamflows with regards to those observed in these real-world basins.

scholarly journals Analysis of modern construction projects using montecarlo simulation technique

2018 ◽  
Vol 7 (2.19) ◽  
pp. 41
Author(s):  
A. M. Arunmohan ◽  
M. Lakshmi
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Quantitative Analysis ◽  
Construction Projects ◽  
Project Success ◽  
Risk Identification ◽  
Project Schedule ◽  
Montecarlo Simulation ◽  
Total Project Cost ◽  
Total Project

Today, Construction based Industry is the prospering industry which has a high economical influence on any nation. Delay in the huge construction project increases the total project cost. Henceforth, uncertainties as well as risks must be significantly regarded during the project. For organizing and completing the projects in a financially, timely and qualitatively accountable manner, careful scheduling of projects is compulsory. Effectual scheduling of project assures project success. This study concentrates on qualitative analysis, risk identification, together with quantitative analysis. The targets are i) to ascertain the key risk aspects that disturb the project schedule, and ii) to find the probability of finishing the project within specified time. Questionnaires are distributed amongst 20 industry practitioners with disparate experience from [1] to [25] years.  Quantitative analysis is made by the methods like Monte Carlo simulation (MCS) and PERT. @RISK by Palisade corp. is utilized for MCS.

scholarly journals New Delay-Dependent Exponential Stability Criteria for Neural Networks with Mixed Time-Varying Delays

2015 ◽  
Vol 2015 ◽  
pp. 1-16
Author(s):  
Wu Wen ◽  
Kaibo Shi
Keyword(s):  
Neural Networks ◽  
Exponential Stability ◽  
Linear Matrix ◽  
Optimization Approach ◽  
Time Varying ◽  
Stability Criteria ◽  
Decision Variables ◽  
Mathematical Techniques ◽  
Delay Dependent ◽  
The Relationship

This study is concerned with the problem of new delay-dependent exponential stability criteria for neural networks (NNs) with mixed time-varying delays via introducing a novel integral inequality approach. Specifically, first, by taking fully the relationship between the terms in the Leibniz-Newton formula into account, several improved delay-dependent exponential stability criteria are obtained in terms of linear matrix inequalities (LMIs). Second, together with some effective mathematical techniques and a convex optimization approach, less conservative conditions are derived by constructing an appropriate Lyapunov-Krasovskii functional (LKF). Third, the proposed methods include the least numbers of decision variables while keeping the validity of the obtained results. Finally, three numerical examples with simulations are presented to illustrate the validity and advantages of the theoretical results.

Improving the flood control at a lower cost for a future Hydro-Québec hydroelectric facility on the Toulnustouc River, Canada

2003 ◽  
Vol 30 (4) ◽  
pp. 775-779 ◽  
Author(s):  
M Gaudette ◽  
G Bulota
Keyword(s):  
Flood Control ◽  
Lower Cost ◽  
Additional Cost ◽  
Control Cost ◽  
Project Cost ◽  
New Approach ◽  
Reservoir Volume ◽  
Total Project Cost ◽  
Total Project

Prior to the construction of a new hydroelectric facility on the Toulnustouc River, Quebec, Canada, optimization was carried out on the dams and spillway design, resulting in a CAN$6 million reduction in the total project cost while improving flood control. This result was obtained using a new approach to the design of civil works, in which the dam and spillway were in complete interaction with one another. In this approach, the possibility of increasing the freeboard of the dams more than that usually required by Hydro-Québec criteria was allowed. The additional freeboard or reservoir volume is strictly assigned to flood control to reduce the maximum released discharge to existing downstream facilities. The raising of dam crests generates additional cost that is more than compensated for by a reduction in spillway capacity and cost.Key words: flood, control, cost, spillway, dam, optimization, security, freeboard.

scholarly journals Cost Optimal Project Scheduling

Organizacija ◽  
2008 ◽  
Vol 41 (4) ◽  
pp. 153-158
Author(s):  
Uroš Klanšek ◽  
Mirko Pšunder
Keyword(s):  
Nonlinear Programming ◽  
Objective Function ◽  
Project Scheduling ◽  
Programming Approach ◽  
Project Duration ◽  
Numerical Example ◽  
Activity Duration ◽  
The Cost ◽  
Total Project Cost ◽  
Total Project

Cost Optimal Project SchedulingThis paper presents the cost optimal project scheduling. The optimization was performed by the nonlinear programming approach, NLP. The nonlinear total project cost objective function is subjected to the rigorous system of the activity precedence relationship constraints, the activity duration constraints and the project duration constraints. The set of activity precedence relationship constraints was defined to comprise Finish-to-Start, Start-to-Start, Start-to-Finish and Finish-to-Finish precedence relationships between activities. The activity duration constraints determine relationships between minimum, maximum and possible duration of the project activities. The project duration constraints define the maximum feasible project duration. A numerical example is presented at the end of the paper in order to present the applicability of the proposed approach.

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