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1 – 10 of over 1000Olalekan Shamsideen Oshodi and Ka Chi Lam
Fluctuations in the tender price index have an adverse effect on the construction sector and the economy at large. This is largely due to the positive relationship that exists…
Abstract
Fluctuations in the tender price index have an adverse effect on the construction sector and the economy at large. This is largely due to the positive relationship that exists between the construction industry and economic growth. The consequences of these variations include cost overruns and schedule delays, among others. An accurate forecast of the tender price index is good for controlling the uncertainty associated with its variation. In the present study, the efficacy of using an adaptive neuro-fuzzy inference system (ANFIS) for tender price forecasting is investigated. In addition, the Box–Jenkins model, which is considered a benchmark technique, was used to evaluate the performance of the ANFIS model. The results demonstrate that the ANFIS model is superior to the Box–Jenkins model in terms of the accuracy and reliability of the forecast. The ANFIS could provide an accurate and reliable forecast of the tender price index in the medium term (i.e. over a three-year period). This chapter provides evidence of the advantages of applying nonlinear modelling techniques (such as the ANFIS) to tender price index forecasting. Although the proposed ANFIS model is applied to the tender price index in this study, it can also be applied to a wider range of problems in the field of construction engineering and management.
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This study/paper aims to present a separable identification algorithm for a multiple input single output (MISO) continuous time (CT) hybrid “Box–Jenkins”.
Abstract
Purpose
This study/paper aims to present a separable identification algorithm for a multiple input single output (MISO) continuous time (CT) hybrid “Box–Jenkins”.
Design/methodology/approach
This paper proposes an optimal method for the identification of MISO CT hybrid “Box–Jenkins” systems with unknown time delays by using the two-stage recursive least-square (TS-RLS) identification algorithm.
Findings
The effectiveness of the proposed scheme is shown with application to a simulation example.
Originality/value
A two-stage recursive least-square identification method is developed for multiple input single output continuous time hybrid “Box–Jenkins” system with multiple unknown time delays from sampled data. The proposed technique allows the division of the global CT hybrid “Box–Jenkins” system into two fictitious subsystems: the first one contains the parameters of the system model, including the multiple unknown time delays, and the second contains the parameters of the noise model. Then the TS-RLS identification algorithm can be applied easily to estimate all the parameters of the studied system.
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The purpose of this paper is to study the identification methods for multivariable nonlinear Box‐Jenkins systems with autoregressive moving average (ARMA) noises, based on the…
Abstract
Purpose
The purpose of this paper is to study the identification methods for multivariable nonlinear Box‐Jenkins systems with autoregressive moving average (ARMA) noises, based on the auxiliary model and the multi‐innovation identification theory.
Design/methodology/approach
A multi‐innovation generalized extended least squares (MI‐GELS) and a multi‐innovation generalized ex‐tended stochastic gradient (MI‐GESG) algorithms are developed for multivariable nonlinear Box‐Jenkins systems based on the auxiliary model. The basic idea is to construct an auxiliary model from the measured data and to replace the unknown terms in the information vector with their estimates (i.e. the outputs of the auxiliary model).
Findings
It is found that the proposed algorithms can give high accurate parameter estimation compared with existing stochastic gradient algorithm and recursive extended least squares algorithm.
Originality/value
In this paper, the AM‐MI‐GESG and AM‐MI‐GELS algorithms for MIMO Box‐Jenkins systems with nonlinear input are presented using the multi‐innovation identification theory and the proposed algorithms can improve the parameter estimation accuracy. The paper provides a simulation example.
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Moêz Soltani and Abdelkader Chaari
The purpose of this paper is to present a new methodology for identification of the parameters of the local linear Takagi‐Sugeno fuzzy models using weighted recursive least…
Abstract
Purpose
The purpose of this paper is to present a new methodology for identification of the parameters of the local linear Takagi‐Sugeno fuzzy models using weighted recursive least squares. The weighted recursive least squares (WRLS) is sensitive to initialization which leads to no converge. In order to overcome this problem, Euclidean particle swarm optimization (EPSO) is employed to optimize the initial states of WRLS. Finally, validation results are given to demonstrate the effectiveness and accuracy of the proposed algorithm. A comparative study is presented. Validation results involving simulations of numerical examples and the liquid level process have demonstrated the practicality of the algorithm.
Design/methodology/approach
A new method for nonlinear system modelling. The proposed algorithm is employed to optimize the initial states of WRLS algorithm in two phases of learning algorithm.
Findings
The results obtained using this novel approach were comparable with other modeling approaches reported in the literature. The proposed algorithm is able to handle various types of modeling problems with high accuracy.
Originality/value
In this paper, a new method is employed to optimize the initial states of WRLS algorithm in two phases of the learning algorithm.
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One of the major obstacles contributing to the cost, time and efficiency of improving the quality output of manufacturing systems is the propagation of defectives or errors…
Abstract
One of the major obstacles contributing to the cost, time and efficiency of improving the quality output of manufacturing systems is the propagation of defectives or errors through the system. Conventional individual control chart design does not address the problem of the interrelation of the processes adequately. Owing to the increasing complexity of manufacturing systems as well as the problems caused by the natural variability of the systems, trial‐and‐error methods are the most commonly used technique for the implementation of the control charts. Trial‐and‐error methods are very costly, time consuming and highly disruptive to the real system. Hence, a systematic and holistic computer‐based methodology is proposed in this paper to obtain a control chart configuration which improves productivity and quality, and reduces cost. Simulation is used as a platform to conduct the control chart system design because different scenarios can be tested off‐line so that statistical process control can be performed effectively without making costly mistakes and disturbing the real system.
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Xuehai Wang and Feng Ding
The purpose of this paper is to study the parameter estimation problem of nonlinear multivariable output error moving average systems.
Abstract
Purpose
The purpose of this paper is to study the parameter estimation problem of nonlinear multivariable output error moving average systems.
Design/methodology/approach
A partially coupled extended stochastic gradient algorithm is presented for nonlinear multivariable systems by using the decomposition technique.
Findings
The proposed algorithm can realize the coupled computation of the parameter estimates between subsystems.
Originality/value
This paper develops a coupled parameter estimation algorithm for nonlinear multivariable systems and directly estimates the system parameters without over-parameterization.
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– The purpose of this paper is to solve the heavy computational problem of parameter estimation algorithm.
Abstract
Purpose
The purpose of this paper is to solve the heavy computational problem of parameter estimation algorithm.
Design/methodology/approach
Presents a decomposition least squares based iterative identification algorithm.
Findings
Can estimate the parameters for linear or pseudo-linear systems and have lower computational burden.
Originality/value
This paper adopts a decomposition technique to solve engineering computation problems and offers a potential and efficient algorithm.
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Explores pricing and advertising in respect to how formal methods of research and analysis can help the pricing decision. Shows that available technique of data collection and…
Abstract
Explores pricing and advertising in respect to how formal methods of research and analysis can help the pricing decision. Shows that available technique of data collection and analysis, although having limitations, can be of great help in making executive decisions.
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This paper discusses the use of stochastic models based on the Box‐Jenkins modeling methodology to determine the future electrical loads. The developed forecasting models have…
Abstract
This paper discusses the use of stochastic models based on the Box‐Jenkins modeling methodology to determine the future electrical loads. The developed forecasting models have been applied successfully by using the electrical load data provided by the Oklahoma Gas and Electric Company.
Mehdi Dehghan and Masoud Hajarian
Solving the non‐linear equation f(x)=0 has nice applications in various branches of physics and engineering. Sometimes the applications of the numerical methods to solve…
Abstract
Purpose
Solving the non‐linear equation f(x)=0 has nice applications in various branches of physics and engineering. Sometimes the applications of the numerical methods to solve non‐linear equations depending on the second derivatives are restricted in physics and engineering. The purpose of this paper is to propose two new modified Newton's method for solving non‐linear equations. Convergence results show that the order of convergence of the proposed iterative methods for a simple root is four. The iterative methods are free from second derivative and can be used for solving non‐linear equations without computing the second derivative. Finally, several numerical examples are given to illustrate that proposed iterative algorithms are effective.
Design/methodology/approach
In this paper, first the authors introduce two new approximations for the definite integral arising from Newton's theorem. Then by considering these approximations, two new iterative methods are provided with fourth‐order convergence which can be used for solving non‐linear equations without computing second derivatives.
Findings
In this paper, the authors propose two new iterative methods without second derivatives for solving the non‐linear equation f(x)=0. From numerical results, it is observed that the new methods are comparable with various iterative methods. Also numerical results corroborate the theoretical analysis.
Originality/value
The best property of these schemes is that they are second derivative free. Also from numerical results, it is observed that the new methods are comparable with various iterative methods. The numerical results corroborate the theoretical analysis.
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