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When making going concern assessments, Statement on Auditing Standards No. 59 (Auditing Standards Board 1988) directs auditors to consider the nature of management's plans and ability to mitigate periods of financial distress successfully. Corporate governance factors reflect attributes of control, oversight, and/or support of management's plans and actions intended to overcome financial distress. Correspondingly, this study investigates the impact of certain corporate governance factors on the likelihood of a going concern modification. Using survival analysis techniques, we examine a sample of 161 financially distressed firms for the time period 1988–1996. We find that auditors are twice as likely to issue a going concern modification when the CEO is replaced. We also find that going concern modifications are inversely associated with blockholder ownership. We also confirm Carcello and Neal's (2000) findings with respect to the association between an independent audit committee and an increased likelihood of modification. In a repeated events setting, we find that insider ownership and board independence are inversely associated with repeated going concern modifications. Our study concludes by proposing implications for the current financial reporting environment (including the Sarbanes‐Oxley Act of 2002) and future research avenues.

The purpose of this paper is to establish and implement a direct topological reanalysis algorithm for general successive structural modifications, based on the updating matrix triangular factorization (UMTF) method for non-topological modification proposed by Song et al. [Computers and Structures, 143(2014):60-72].

In this method, topological modifications are viewed as a union of symbolic and numerical change of structural matrices. The numerical part is dealt with UMTF by directly updating the matrix triangular factors. For symbolic change, an integral structure which consists of all potential nodes/elements is introduced to avoid side effects on the efficiency during successive modifications. Necessary pre- and post processing are also developed for memory-economic matrix manipulation.

The new reanalysis algorithm is applicable to successive general structural modifications for arbitrary modification amplitudes and locations. It explicitly updates the factor matrices of the modified structure and thus guarantees the accuracy as full direct analysis while greatly enhancing the efficiency.

Examples including evolutionary structural optimization and sequential construction analysis show the capability and efficiency of the algorithm.

This innovative paper makes direct topological reanalysis be applicable for successive structural modifications in many different areas.

The finite element method has been increasingly applied in stress, thermal and dynamic analysis of gear transmissions. Preparing the models with different design and modification parameters for the finite element analysis is a time-consuming and highly skilled burden.

To simplify the preprocessing work of the analysis, a parametric finite element modeling method for spur and helical gears including profile and lead modification is developed. The information about the nodes and elements is obtained and exported into the finite element software to generate the finite element model of the gear automatically.

By using the three-dimensional finite element tooth contact analysis method, the effects of tooth modifications on the transmission error and contact stress of spur and helical gears are presented.

The results demonstrate that the proposed method is useful for verifying the modification parameters of spur and helical gears in the case of deformations and misalignments.

The purpose of this study is to evaluate whether the classification of the equity mutual fund depends on the performance measure used.

The sample for this study includes stock mutual funds for the USA, Europe and emerging market economies covering the period 2010 to 2020. Using more than 20 performance measures the results are compared using the Sharpe ratio as the reference.

The results show that performance measures based on absolute reward–risk ratios like Sortino, Treynor, etc. have similar rankings, because in general the numerator (mean excess return) is the same. However, when the authors employ other types of performance measures, results may be significantly different, especially in the case of metrics for “incremental returns”, i.e. alphas. Focussing on markets, their results show that choosing performance measures is more relevant for emerging markets.

The sample is only limited to the USA, Europe and the emerging market, and there are other performance metrics in the literature which have not been covered in this work.

The ordering of equity mutual funds depends on the measure used, specially if investors employ factor models to measure excess returns (alphas). Hence, policy formulation on disclosure of mutual fund performance should encourage the use of several metrics from different families. Investors must be aware of the different rankings made and the most appropriate metrics based on their preferences.

This paper focusses specifically on the effect that performance metrics have on relative fund performance. Previous studies have ignored alpha metrics to rank funds, which are commonly employed by investors. The authors’ study performs an analysis for three different markets considering the two main developed ones (the American and European equity markets), as well as the emerging one, largely ignored until now.

This study aims to produce a superhydrophobic fabric surface with a layered rough structure and which are resistant to droplet adhesion. Polydimethylsiloxane (PDMS) systems doped with stearic acid modified titanium dioxide (SA-TiO₂) nanoparticles was sprayed onto the surface of cotton fabric.

This experiment therefore uses a simple method to prepare superhydrophobic textiles by spraying SA-TiO₂ particles mixed with PDMS onto the surface of cotton fabrics. The effects of the ratio of stearic acid to TiO₂, spraying times and tension on the apparent morphological structure and hydrophobic properties of the cotton fabric were investigated.

The results showed that the stearic acid-modified TiO₂ nanoparticles were hydrophobic and more uniformly dispersed in the PDMS solution. When the modification ratio of stearic acid to TiO₂ was 3:5, the water contact angle of cotton fabric was 155.48° and sliding angle was 6.67° under the applied tension for three times of spraying, showing superhydrophobicity. The fabric shows super hydrophobic and anti-adhesive properties to a wide range of liquids such as cola, dyeing liquids, tea, milk and simulated blood. The surface tension of the liquid shows a negative correlation with its adhesion to the fabric.

The SA-TiO₂ and PDMS were applied to the fabric surface by spraying, which not only gave the fabric superhydrophobic properties, but also created anti-adhesion to a wide range of droplets.

The superhydrophobic cotton fabrics prepared by this method showed good anti-adhesive behavior to common stains and simulated blood and can be used in the development of medical protective textiles.

Modification of TiO₂ with stearic acid to prepare SA-TiO₂ with excellent hydrophobic properties, which was mixed with PDMS to make suspensions. Fluorine-free superhydrophobic fabrics were prepared by spraying method. It also exhibited excellent anti-adhesive properties against blood, providing a reference for the preparation of self-cleaning and anti-adhesive surgical gowns.

Several studies were made on paired site and soil–structure interaction (SSI) effects, but most of them were site specific. This paper aims to investigate the impact of SSI effects in conjunction with local soil condition effects on the seismic response of typical multistory low- to mid-rise–reinforced concrete (RC) buildings resting on Algerian regulatory design sites through a global explicit transfer function (TF).

A preliminary quantification of SSI effects associated with site effects is carried out through a frequency-domain solution based on the concept of rock-to-soil surface displacement TF performed for each design site category. It results from the combination of the TFs of structure, foundation and soil and reflects how seismic waves are amplified due to changes in the geological contrast between the rock and overlying soil deposits. As well, response modification factors, denoting displacement ratios of the building responses within the flexible and site-structure conditions with respect to the fixed-base one, are carried out.

In the context of Algerian seismic regulation, the study provides a clear vision of how and when site or SSI effects are expected to be influential, as opposed to the fixed-base hypothesis still retained by the current regulation. This helps engineers to be aware of the extent of the expected seismic damage.

The research applies to low- to mid-rise RC buildings within the Algerian seismic regulation, but it may also be expanded to other examples that fall under other seismic regulations.

The response modification ratio is a quantitative approach to assessing response fluctuations. It draws attention to how the roof level drift varies depending on the condition. These results can be used as numerical parameters in structural seismic design when the structure is comparable because they provide useful information about how the two phenomena interact with the structure.

The study goes beyond particular situations dealing with site specific and offers effective indicators and quantitative evaluation of combined site and SSI effects according to the current national seismic provisions, where no indication about site or SSI effects exists.

This paper aims to provide designers/engineers, in engineering structural design and analysis, approaches to freely and accurately modify structures (geometric and/or material), and then quickly provide real-time capability to obtain the numerical solutions of the modified structures (designs).

The authors propose an isogeometric independent coefficients (IGA-IC) method for a fast reanalysis of structures with geometric and material modifications. Firstly, the authors seamlessly integrate computer-aided design (CAD) and computer-aided engineering (CAE) by capitalizing upon isogeometric analysis (IGA). Hence, the authors can easily modify the structural geometry only by changing the control point positions without tedious transformations between CAE and CAD models; and modify material characters simply based on knots vectors. Besides, more accurate solutions can be obtained because of the high order degree of the spline functions that are used as interpolation functions. Secondly, the authors advance the proposed independent coefficients method within IGA for fast numerical simulation of the modified designs, thereby significantly reducing the enormous time spent in repeatedly numerical evaluations.

This proposed scheme is efficient and accurate for modifying the structural geometry by simply changing the control point positions, and material characters by knots vectors. The enormous time spent in repeated full numerical simulations for reanalysis is significantly reduced. Hence, enabling quickly modifying structural geometry and material, and analyzing the modified model for practicality in design stages.

The authors herein advance and propose the IGA-IC scheme. Where, it provides designers to fasten and simple designs and modify structures (both geometric and material). It then can quickly in real-time obtain numerical solutions of the modified structures. It is a powerful tool in practical engineering design and analysis process for local modification. While this method is an approximation method designed for local modifications, it generally cannot provide an exact numerical solution and its effectiveness for large modification deserves further study.

The prediction of critical velocity at instability threshold for shell and tube heat exchangers is important to avoid failure of tubes as a result of flow-induced vibrations due to water cross flow. The flow-induced vibration in finned tube heat exchangers is affected by various parameters such as fin height, fin pitch, fin material, tube array, pitch ratio, fin type, fluid velocity etc. In this paper, an experimental investigation of fluid elastic instability in shell and tube heat exchangers is carried out by subjecting normal square finned tube arrays of pitch ratio 1.79 to water cross flow.

The five tube arrays, namely plain array, two finned tube arrays with 3 fpi and 9 fpi fin density, and two finned tube arrays with 3 mm and 6 mm fin height are tested in the experimental test setup with water flow loop and vibration measurement system. The research objective is to evaluate the effect of fin density and fin height on the instability threshold. The critical velocity at instability threshold is determined to characterize the fluid elastic instability behavior of different tube arrays. The vortex shedding behavior of the tube arrays is also studied by determining Strouhal number corresponding to the small peaks before fluid elastic instability.

The fluid elastic instability behavior of the tube arrays was found to be the function of fin tube parameters. The experimental results indicate that an increase in fin density and fin height results in delaying the instability threshold for finned tube arrays. It is also observed that critical velocity at instability is increased for finned tube arrays compared to plain tube arrays of the same pitch ratio. The design modifications in the outer box have resulted in further reduction in the natural frequency. This enabled to reach clear instability for all the five-tube arrays.

The research data add the value to the present body of knowledge by knowing the effect of fin height and fin density on the fluid elastic instability threshold of normal square finned tube arrays subjected to water cross flow.

WE concluded Part II of this series with the remark that a different outlook is needed for problems of control surface flutter than for those of wing flutter. There are two reasons for this. Wing flutter must be investigated carefully early on in the design of an aircraft so as to provide a safe aircraft without a severe weight penalty, whereas the weight penalty of avoiding control surface flutter is usually small, although not negligible, and modifications can often be made at short notice, so it is important to make a full investigation as late as possible before flight when all the data are available in a reliable form. The second reason is that with wing flutter, as with aileron reversal and divergence, it is usual to think of safety margins in terms of forward speed or possibly wing torsional stiffness; with control surface flutter, on the other hand, quite different types of safety factor become the rule.

IS there anything magic about the shape of a wing section? Asked to sketch the profile of a wing on the back of an envelope, one would have no difficulty in representing a shape which would probably, for most purposes, be adequate. Assuming this generalization to be true—perhaps it is a rather rash one—one might equally well question the need for an article on aerofoil design, or indeed the need for the long and painstaking research which, over the years, has been conducted on this particular subject. But it is this same research which, in the long run, has resulted in the recognition of certain general rules relating to aerofoil geometry, which are now taken so much for granted that they would probably be embodied in one's preconceived notion of what a wing section should look like. Recently, also, rather complicated theoretical techniques have made possible the design of profiles which, if manufactured faithfully and carefully in each detail, can provide a performance which is considerably better than any more arbitrary shaping to general rules would produce. Finally, of course, one must recognize that there are exceptional conditions where the application of conventional ideas is inadvisable, and where theoretical and experimental research is needed to suggest what is more appropriate. This article will be concerned for the most part with amplifying these remarks; but, by and large, it must be admitted at the outset that we cannot point to any revolutionary discontinuities in the progress of aerofoil design such as have characterized advances in the means of aircraft propulsion, or structural design.