Search results

The purpose of this paper is to explore whether the provision of non-audit services (NAS) by public accounting firms undermines audit quality. The study addresses this question by testing for an association between the provision of consulting services and auditor independence in listed companies.

The authors study if the magnitude of non-audit fees explains variations in earnings management by looking at the joint determination of non-audit fees, audit fees, and abnormal accruals using the SURE-regression estimation method.

Evidence from tested models suggests that audit services quality is uncompromised by the provision of NAS. In other words, high non-audit fees do not necessarily result in poor quality financial reporting.

A different research methodology and a different sample (e.g. non-listed companies) may lead to differing results. As the paper analyses only one country, generalizability of the results might be a limitation. There is no need to increase legal restrictions on the provision of consulting services by public accounting firms in order to better safeguard audit quality.

Consulting clients may be more confident to hire both audit and NAS with the same firm and can make a case before the general Shareholders’ meeting. By providing both audit and NAS, consulting firms obtain knowledge spillovers and synergies while appealing highly qualified professionals.

The use of simultaneous equations (SURE-regression) to establish the auditor-client relation allows us to better model theoretical relations between audit fees, non-audit fees, and abnormal accruals. Likewise, joint modeling takes account of correlations between the error terms of the individual models, yielding more efficient estimates than ordinary least squares. Performing this analysis in a non-Anglo-American country with low litigation risk is also a valuable contribution to extant literature.

The purpose of this paper is the simultaneous determination of optimal replacement threshold and inspection scheme for a system within condition-based maintenance (CBM) framework.

A proportional hazards model (PHM) is used for risk of failure and a Markovian process to model the system covariates. Total expected long-run cost (including replacement, inspection and downtime costs) is formulated in terms of replacement threshold and inspection scheme. Through an iterative procedure, for all different values of replacement thresholds, their associated optimal inspection scheme is determined using an effective search algorithm. By evaluating the corresponding costs, the optimal replacement threshold and its associated optimal inspection scheme are, then, identified.

The mathematical formulation, that takes into account all different costs, required for the simultaneous determination of optimal replacement threshold and optimal inspection scheme for an item subjected to CBM using PHM is provided. The proposed approach is compared against classical age policy and one state-of-the-art policy through a numerical example. The results show that the proposed approach outperforms other comparing policies.

In practical situations where CBM is implemented, inspections and downtime often incur cost. Under such circumstances, findings of this paper can be utilized for the determination of optimal replacement threshold and optimal inspection scheme so that the CBM cost is minimized.

In most of the reported researches, it is often assumed that inspections have no cost and/or that the time for replacements (either preventive or at failure) is negligible. In the contrary, in this paper the author takes all cost factors including inspection costs, replacement time(s) and their associated downtime costs into account in the simultaneous determination of optimal replacement threshold and optimal inspection scheme.

The knowledge of the heat transfer coefficient is important for the proper design of heat exchangers as well as for the determination of the working medium outlet temperatures. This paper aims to present a method of simultaneous determination of coefficients in correlation formulas for the Nusselt number on both sides of the heat transfer surface.

The idea of the developed method is based on determining such a values of the coefficients in Nusselt number correlations that fulfill the condition of equality between the measured and calculated temperature at the outlet of heat exchanger in terms of least squares method. To test the proposed method, a special experimental installation was built. The heat transfer in helically coiled tube-in-tube heat exchanger was examined for the wide range of temperature changes and volumetric flow rates of working fluid.

The simulation results were validated with an experimental data. The results show that the heat transfer coefficient of the counter-current is higher than the co-current flow in helically coiled heat exchanger. This phenomenon can be beneficial particularly in the laminar flow regime.

The correlation for the Nusselt number as a function of the Reynolds and Prandtl numbers for hot and cold liquid was obtained with the least squares method for the experimental data.

The presented method allows for the simultaneous determination of heat transfer coefficient on both sides of the wall without the necessity of indirect calculation of the overall heat transfer coefficient. The presented method can be used in the thermal design of various type heat exchangers.

This work presents the new methodology of determination correlations for the helically coiled tube-in-tube heat exchanger for co-current and counter-current arrangement, which can be used in thermal design.

The purpose of this paper is to present a novel approach based on the artificial bee colony (ABC) algorithm aiming to achieve maximum acceleration and maximum endurance for morphing unmanned aerial vehicle (UAV) design.

Some of the most important issues in the design of UAV are the design of thrust system and determination of the endurance of the UAV. Although propeller selection is very important for the thrust system design, battery selection has the utmost importance for the determination of UAV endurance. In this study, the calculations of maximum acceleration and endurance required by ZANKA-II during the flight are considered simultaneously. For this purpose, a model based on the ABC algorithm is proposed for the morphing UAV design, aiming to achieve the maximum acceleration and endurance. In the proposed model, the propeller diameter, propeller pitch and battery values used in morphing UAV's power system design are selected as the input parameters; maximum acceleration and endurance are selected as the output parameters. To obtain the maximum acceleration and endurance, the optimum input parameters are determined through the ABC algorithm-based model.

Considerable improvements on maximum acceleration and endurance of morphing UAV with ABC algorithm-based model are obtained.

The endurance and acceleration due to the thrust are two separate parameters that are not normally proportional to each other. In this study, optimization of UAV’s endurance and acceleration is considered with equal importance.

Using artificial intelligence techniques causes fast and simple optimization for determination of UAV’s endurance and acceleration with equal importance. In the simulation studies with ABC algorithm, satisfactory results are obtained.

The results of the study have showed that the proposed approach could be an alternative method for UAV designers.

Providing a new and efficient method saves time and reduces cost in calculations of maximum acceleration and endurance of the UAV.

The globalization of markets and businesses has meant that many companies now consider the world as a potential marketplace. In this changing environment, two crucial decisions taken by companies are time of entry (e.g. whether to enter early or late) and level of involvement (e.g. whether to adopt low involvement modes such as exports or high involvement modes such as sole venture). Although existing research has examined these issues and underscored the importance of these two decisions in isolated descriptive research, none has developed an integrated mathematical modeling framework for handling these two decisions simultaneously. To alleviate this important gap in the literature, develops a mathematical model for considering these decisions in a simultaneous framework. The results of the model are illustrated by means of numerical simulations. Managerial implications of the model and future research directions are delineated.

The purpose of this paper is to construct an array of sensors using polypyrrole–zinc oxide (PPy–ZnO) and PPy–vanadium (V; chemical formula: V₂O₅) fibers. To test responses of sensors, a central composite design (CCD) has been used. The results of the CCD technique revealed that the developed sensors are orthogonally sensitive to diacetyl, lactic acid and acetic acid. In total, 20 different mixtures of diacetyl, lactic acid and acetic acid were prepared, and the responses of the array sensors were recorded for each mixture.

A response surface regression analysis has been used for correlating the responses of the sensors to diacetyl, lactic acid and acetic acid concentrations during the gas phase in food samples. The developed multivariate model was used for simultaneous determination of diacetyl, lactic acid and acetic acid concentrations. Some food samples with unknown concentrations of diacetyl, lactic acid and acetic acid were provided, and the responses of array sensors to each were recorded.

The responses of each sensor were considered as target response in a response optimizer, and by an overall composite desirability, the concentration of each analyte was predicted. The present work suggests the applicability of the response surface regression analysis as a modeling technique for correlating the responses of sensor arrays to concentration profiles of diacetyl, lactic acid and acetic acid in food samples.

The PPy–ZnO and PPy–V₂O₅ nanocomposite fibers were synthesized by chemical polymerization. The provided conducting fibers, PPy–ZnO and PPy–V₂O₅, were used in an array gas sensor system for the analysis of volatile compounds (diacetyl, lactic acid and acetic acid) added to yogurt and milk samples.

This paper aims to investigate the determinants and the evolution of voluntarily adopted firm‐level corporate governance practices in Brazil from 1998 to 2004 using broad corporate governance scores.

The authors employ a robust panel‐data procedure that accounts for the main sources of endogeneity to a very representative panel of Brazilian firms over a six‐year period. They address the endogeneity that arises from the simultaneous determination of the quality of corporate governance practices, the dependent variable, and possibly several firm attributes that are commonly employed as the determinants of such practices and are supposedly independent. Specifically, theoretical arguments and empirical evidence strongly suggest that the quality of corporate governance practices may influence some of the variables commonly used as its determinants just as much as they may be influenced by them.

The paper finds that firm‐level corporate governance practices are steadily improving but there is much room for improvement. Heterogeneity has increased. Voluntarily adhering to new stricter listing requirements is associated positively with improvements in firm‐level corporate governance practices. Reducing or not using non‐voting shares improves corporate governance practices.

The authors found no clear evidence of the influence of other potential determinants of the quality of corporate governance, such as growth prospects, firm size, firm value, and ownership structure. Thus, they doubt previous findings that suggest a causal relationship from value and ownership to corporate governance practices because value and ownership seem to be determined endogenously.

Policies directed to reduce the use of non‐voting shares should be implemented. Creating strict listing requirements that may be adopted voluntarily by firms could be a feasible solution to improve the quality of corporate governance practices in emerging market countries. Firms in an emerging market that find that issuance in the USA became too expensive or demanding may offer a substitute listing environment with credible requirements to foreign investors. Premium listings may partially compensate emerging market exchanges for their loss of trading to major markets.

The paper examines the evolution of the voluntary adoption of corporate governance practices in Brazil from 1998 through 2004 while most studies use cross‐section samples over one or a few years. Further, this is one of a few papers to analyze the impact of ownership structure on the quality of corporate governance practices by segregating control and cash flow rights.

The present study aims to determine the existence of simultaneous relationship between economic growth, income inequality, fiscal policy, and total trade of the 13 emerging market economies as a group for the period 1980–2010. After establishing the existence of simultaneity between the above relationships, a simultaneous panel model has been formulated and estimated incorporating the nonlinearity among the variables as suggested by the existing literature. An inverted U-shape relationship is evident between (1) economic growth, income inequality, and total trade in economic growth equation, (2) income inequality, economic growth, and per capita income in income inequality equation, and (3) total trade and economic growth in total trade equation. Thus, the existence of a two-way nonlinear relationship is highlighted between economic growth, income inequality, and total trade. Apart from these nonlinear relationships, positive and significant effect of (1) gross capital formation, inflation, population growth, human capital, fiscal policy, monetary policy, and domestic credit to private sector on economic growth; (2) civil liabilities on income inequality; (3) gross capital formation and inflation on total trade; (4) total trade, population growth of those aged 65 years and above, political system on fiscal policy is highlighted. Also, negative and significant effect of (1) fiscal policy on income inequality and (2) income inequality on fiscal policy is revealed.