Ahmad Hakimi, Amirhossein Amiri and Reza Kamranrad
The purpose of this paper is to develop some robust approaches to estimate the logistic regression profile parameters in order to decrease the effects of outliers on the…
Abstract
Purpose
The purpose of this paper is to develop some robust approaches to estimate the logistic regression profile parameters in order to decrease the effects of outliers on the performance of T2 control chart. In addition, the performance of the non-robust and the proposed robust control charts is evaluated in Phase II.
Design/methodology/approach
In this paper some, robust approaches including weighted maximum likelihood estimation, redescending M-estimator and a combination of these two approaches (WRM) are used to decrease the effects of outliers on estimating the logistic regression parameters as well as the performance of the T2 control chart.
Findings
The results of the simulation studies in both Phases I and II show the better performance of the proposed robust control charts rather than the non-robust control chart for estimating the logistic regression profile parameters and monitoring the logistic regression profiles.
Practical implications
In many practical applications, there are outliers in processes which may affect the estimation of parameters in Phase I and as a result of deteriorate the statistical performance of control charts in Phase II. The methods developed in this paper are effective for decreasing the effect of outliers in both Phases I and II.
Originality/value
This paper considers monitoring the logistic regression profile in Phase I under the presence of outliers. Also, three robust approaches are developed to decrease the effects of outliers on the parameter estimation and monitoring the logistic regression profiles in both Phases I and II.
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Keywords
Reyhane Hashemi, Reza Kamranrad, Farnoosh Bagheri and Iman Emami
The aim of this paper is to predict and minimize the risks of oil, gas and petrochemical projects. Besides, reducing the likelihood of occurrence and minimizing risks impact on…
Abstract
Purpose
The aim of this paper is to predict and minimize the risks of oil, gas and petrochemical projects. Besides, reducing the likelihood of occurrence and minimizing risks impact on the projects to reduce the probable costs and improve the economic situation is another purpose of this paper.
Design/methodology/approach
This paper provides a fuzzy Decision-Making Trial and Evaluation Laboratory (DEMATEL) – a technique that assist to solve decision-making problems – and IP (Impact & Probability) table methods to identify and analyze critical risks in energy projects, and then fuzzy Binary Logistic Regression (BLR) in order to predict the probability of each level of risk for more efficient risk management in projects. Furthermore, in this paper, the fuzzy BLR (FBLR) is optimized such that the probability of a high level of risk for the implementation of the project has been minimized using meta-heuristic algorithm.
Findings
The results from the point of view of experts show that combination of fuzzy DEMATEL with FBLR approach as well as using SA algorithm, in order to optimize the high level of risks, can provide a smart approach to managing risks with more success.
Practical implications
The application of the proposed method is illustrated via a real data set from energy projects.
Originality/value
We propose combined fuzzy DEMATEL and FBLR methods to predict and optimize the risks of the energy projects, which is the innovation of this paper.
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Mahdi Salehi, Hossein Tarighi and Samaneh Safdari
This paper aims to investigate the effects of some corporate governance mechanisms and executive compensation on audit fees in an emerging market.
Abstract
Purpose
This paper aims to investigate the effects of some corporate governance mechanisms and executive compensation on audit fees in an emerging market.
Design/methodology/approach
The study population consists of 540 observations and 90 listed companies on the Tehran Stock Exchange during the years 2009-2014. The statistical model used in this study is a multivariate regression model; besides, the statistical technique used to test the hypotheses proposed in this research is panel data.
Findings
The changes in the value of a CEO’s own firm stock option portfolio, in thousands of rials (Iran’s currency), for a 0.01 change in stock return volatility and stock price are defined as Vega and Delta, respectively. The results demonstrated that there is a positive association between audit fees and delta, but not Vega; this means that a fee premium is linked to CEO Delta incentives. The findings show that Iranian companies pay more audit fees when they give managers more rewards. In addition, the results show that there is not a significant relationship between fees resulting from audit risk and Delta and Vega incentives of the board. Inconsistent with agency theory, the authors found that the independence of board members did not have any effect on audit fees. As a final point, the outcomes of the paper demonstrate that managers who invest in companies under their own management do not have any impact on the amount of audit fee. To put it another way, there is not any significant connection between the board ownership and audit fees.
Practical implications
This is one of the most important studies that simultaneously surveys the impacts of corporate governance mechanisms and executive compensation in the Iranian audit market. The results of this study will reveal more than the role of corporate governance mechanisms for society and users of financial statements because as tools on the CEO actions, they always have to pay attention to the implementation of corporate principles in the economic entity’ operation.
Originality/value
The present study has examined the relationship between two cases of corporate governance mechanisms named the board independence and the board ownership with audit fees in a country where, to the authors’ knowledge as in most other developing markets, such a relationship has not been a subject of empirical research. Moreover, the use of a two-dimensional measure of executive compensation, namely, Delta and Vega incentives, primarily considering research undertaken in an emerging market, as a valuable contribution may be observed.