Professional Demographic Factors That Influence Iranian Auditors Perceptions Of The Fraud-Detecting Effectiveness Of Red Flags

The purpose of this study is to explore the relationship between professional demographic factors concerning external and internal auditors and the perceived level of effectiveness of the Statement of Auditing Standard (SAS) No. 99 red flags in detecting fraudulent financial reporting activities as perceived by external and internal auditors. The six hypotheses are: (1) the type of auditors using red flags to detect fraud, (2) highest degrees received by auditors, (3) areas that auditors majored in at universities, (4) auditors’ accumulated knowledge of red flags, (5) auditors who have or have not used red flags to detect fraud, and (6) auditors whohave or have not received in-house red flag training.  The six hypotheses explore how six professional demographic factors may influence the level of fraud-detecting effectiveness of the SAS No. 99 red flags as perceived by 227 external and internal auditors in Iran.  The results of this study indicate that all six hypotheses were accepted.   In conclusion, the level of fraud-detecting effectiveness of these red flags as perceived by the Iranian auditors may be influenced by the following factors: (1) the type of auditors, (2) the highest degrees received by auditors, (3) areas that auditors majored in at universities, (4) knowledge about red flags accumulated by auditors, (5) auditors whohave or have not previously used red flags to detect fraud, and (6) auditors whohave or have not previously received in-house red flag training

The evolution of tidal coastal landscapes and the controls on pathways to equilibrium

The evolution of tidal basins is fundamental to understanding the drivers of our vulnerable estuarine and lagoon environments, ultimately determining key ecological parameters such as intertidal area, inundation regime, connectivity and accommodation space. This thesis uses multiple methods including idealized modelling, field observation of an estuarine shoal covered with mangroves, and a calibrated and validated model with field data in order to explore how different components of tidal environments influence the short and long-term dynamics of tidal lagoons. The idealised modelling specifically focused on the roles of initial bathymetry, bed sediment and mud concentration at open boundaries on shaping equilibrium profile development of tidal basins. The results of the model showed that geomorphological development (long-term evolution) is similar in sandy environments with different initial bathymetries and without a mud supply. This was concluded because the equilibrium profiles and tidal asymmetries evolved similarly at the end of simulations. However, residence time, development of channels and energy dissipation were observed to be different. In the case of available incoming mud from open boundaries, equilibrium bathymetry was dominated by the mud supply and sediments accreted all over the domain, forming a mudflat and a deeply incised ebb-dominated channel, with several minor side channels of which their size and number were dependent on mud concentration. The response of tidal environments to sea-level rise has been previously studied often by neglecting the importance of initial configuration in the model. In such process-based modelling, different initial bathymetries are only considered to influence the time to reach a stable equilibrium condition but will always lead to identical equilibrium bathymetry. Here we demonstrated that initial profile not only affects some aspects of tidal basins such as channel formation, residence time and energy dissipation in equilibrium condition, but also impacts their geomorphological development under sea-level rise. In the northern North Island of Aotearoa New Zealand, tidal environment evolution is mediated by mangroves. The governing dynamics on a recently evolving estuarine, mangrove-covered channel-shoal system in Whitianga Estuary, Aotearoa New Zealand. Observations of water level, flow velocity, suspended sediment concentration and bed sediment characteristics were used to infer flow asymmetry and sediment transport pathways around the shoal. The impact of mangrove colonization on channel dynamics, sediment texture of upper layer and mud layer thickness was studied by a one-week field campaign. Due to changes in land use, the estuary was subjected to an increase in sediment supply, causing the tidal flats to elevate and provided suitable conditions for the expansion of mangroves in 1940s. By the use of historical images, the expansion of mangroves in Whitianga Estuary was captured and the results were combined with the measured data of water level, current and sediment dynamics in order to explore the short-term dynamics around the shoal and the role of vegetation as eco-engineers in inter-tidal environments. The shoal expanded laterally independent of mangrove colonization. However, observed mud layer thickness was larger around mangroves compared to un-vegetated parts of the shoal. The mangrove creek (which was a shoal channel before expansion of mangroves) was consistently ebb-dominated and the shoal channel located outside the forest on the edge of the shoal was flood-dominated. The results suggested that mangroves impose a control on their surrounding environment and can ultimately lead to a regime shift in channels and changes in sediment texture. The understanding provided by the field observations was confirmed with a 2-D numerical model, developed in the Delft3D modelling system, which was calibrated and validated with the data collected from the field. This model was used to study the short-term influence of mangroves and tidal creeks on tidal circulation and large-scale tidal asymmetry. The results showed that the effect of vegetation on tidal asymmetry and flow routing was larger compared that of the tidal creeks. However, the small impact of the channels may be due to the small size of the creeks compared to the size of the forest. When vegetation was removed, tidal velocity asymmetry changed substantially whereas channel infilling caused a shift in tidal asymmetry inside the creeks and around the head of the creeks mostly (from being ebb-dominated to flood-dominated). Removing vegetation led to an increase in speed all over the forest except inside the creeks and elevated parts of the forest where velocity decreased. In a scenario in which channels were filled in, currents became weaker in the location of the creeks and velocity increased around the creeks and on the edge of the forest. Furthermore, a scenario was designed in which morphology of the shoal in the 1940s prior to expansion of mangroves was simulated, aiming to quantify the hypothesis posed by field measurement with numerical models. The results of the model demonstrated that mangrove colonization caused a regime shift in the channels, showing that as mangroves colonize inter-tidal areas, they play a critical role in shaping the geomorphology. In Whitianga Estuary, expansion of mangroves around changed a flood-dominated pre-existing shoal channel to an ebb-dominated mangrove creek, suggesting that mangroves are likely to be eco-engineers of the estuarine system. The idealized modelling experiments helped identifying the parameters and elements that govern the long-term morphology and equilibrium of coastal tide-dominated environments and the way they respond to sea-level rise force. Results of this theoretical exploration showed that processes localised, and timescales for equilibrium development vary vastly across the landscape. Elucidating local changing to asymmetry became the focus of subsequent chapters, firstly with a field exploration, and then supported by numerical modelling. The fieldwork presented here elucidated the short-term hydrodynamics and suspended sediment dynamics in an estuarine shoal covered with mangroves. Moreover, observation of aerial images in a multi-decadal timescale combined with hydrodynamics inside a mangrove creek and a shoal channel highlighted the complex non-linear interactions of hydrodynamics and vegetation that lead to a regime shift of a channels in the mangrove forest in Whitianga Estuary, Aotearoa New Zealand. Finally, the results of the numerical model developed and validated by utilizing field data presented here provided insights into the detailed short-term hydrodynamics. Moreover, the scenarios designed by removing channels, vegetation and reconstructing the condition prior to mangrove expansion showed that the effect of vegetation extends beyond the footprint of the vegetation to the surrounding environment with implications for hydrodynamics, morphological evolution and channel dynamics

On the Influence of Antecedent Morphology on Development of Equilibrium Bathymetry in Estuaries Past and Future

Although analytical and numerical models have been widely used to explore evolution and equilibrium morphology in tidal environments, less attention has been paid to examining the impact of initial bathymetry on the model outcomes. Here we use two-dimensional idealized models with contrasting initial bathymetries to study how the interactions between antecedent morphology and tidal exchange processes determine the establishment of an estuarine equilibrium bathymetry, and how these interactions mediate the morphodynamic response to rising sea levels. In all model runs with sandy beds, inter-tidal zones reach the equilibrium condition first and equilibrium profiles are similar for points close to mean seal level. However, key aspects like channel formation, residence time and energy dissipation do not evolve to the same state and are inherited from the initial bathymetry. This implies that responses to sea-level rise (SLR) are different as well. Conversely, in cases with mud and sand input at the boundaries, equilibrium occurs more quickly and the equilibrium bathymetry and channel formation are dominated by the boundary mud concentration. General implications of the study are that predictions of coastal response to changes such as SLR depend on initial bathymetric conditions

Regulation with Guaranteed Convergence Rate for Continuous-Time Systems with Completely Unknown Dynamics in the Presence of Disturbance

This paper presents the design of a novel H ∞ -based control framework for state regulation of continuous-time linear systems with completely unknown dynamics. The proposed method solves the regulation problem with the desired convergence rate and simultaneously seeks to attenuate the adverse effect of disturbance on the system. The H ∞ regulation problem assumes a cost function that considers regulation with a guaranteed rate of convergence as well as disturbance attenuation. The problem is then turned into a two-player zero-sum game optimization problem that can be solved by solving the associated algebraic Riccati equation (ARE), which provides a model-based solution. To solve this problem in a model-free way, a novel integral reinforcement learning (IRL) algorithm is designed to learn the solution online without requiring any prior knowledge of the system dynamics. It is shown that the model-free method (i.e., IRL-based method) provides the same solution as the model-based method (i.e., ARE). The effectiveness of the proposed method is ascertained through simulation examples; it is shown that the proposed method effectively addresses the problem for both stable and unstable systems