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Displacement: Translation and Rotation. Differences and Similarities in the Discrete and Continuous Models
104-124Views:272The motion (displacement) of the Euclidean space can be decomposed into translation and rotation. The two kinds of motion of the Euclidean space based on two structures of the Euclidean space: The first one is the topological structure, the second one is the idea of distance. The motion is such a (topological) map, that the distance of any two points remains the same. The bounded and closed domain of the Euclidean space is taken as a model of the rigid body. The bounded and closed domain of the Euclidean space is also taken as a model of the deformable solid body. The map – i.e. the displacement field – of the deformable solid body is continuous, but is not (necessarily) motion; the size and the shape of body can change. The material has atomic-molecular structure. In compliance with it, the material can be comprehended as a discrete system. In this case the elements of the material, as an atom, molecule, grain, can be comprehended as either material point, or rigid body. In the first case the kinematical freedom is the translation, in the latter case the translation and the rotation. In the paper we analyse how the kinematical behaviour of the discrete and continuous mechanical system can be characterise by translation and rotation. In the discrete system the two motions are independent variable. At the same time they characterise the movement of the body different way. For instance homogeneous local translation gives the global translation, but the homogeneous local rotation does not give the global rotation. To realise global rotation in a discrete system on one hand global rotation of the position of the discrete elements, on the other hand homogeneous local rotations of the discrete elements in harmony with global rotation are required. In the continuous system the two kinds of movement cannot be interpreted: a point cannot rotate, a rotation of surrounding of a point or direction can be interpreted. The kinematical characteristics, as the displacement (practically this is equal to translation) of (neighbourhood of) point, the rotation of surrounding of that point and the rotation of a direction went through that point are not independent variables: the translation of a point determines the rotation of the surrounding of that point as well as the rotation of a direction went through that point. With accordance this statement the displacement (practically translation) (field) as the only kinematical variable can be interpreted in the continuous medium.
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The Propensity for Mandatory Audit Rotation and its Impact on Earnings Management in Europe
222-233Views:395The doubt of investors for the accuracy of financial reporting statements and the credibility of external audit functions has becoming more and more severe in the recent years due to a variety of booming accounting scandals related to earnings management occurring around the world. To cope with these serious frauds in the world of financial market, many countries have adopted Mandatory Audit Rotation (MAR) rules. Although the MAR rule has been valid around European Union (EU) members since 2016, the effectiveness of this rule has not been examined in any academic papers yet. As a result, the aim of this study is to investigate the effectiveness and the necessity of the latest MAR rule in the EU by testing the influence of audit rotation activities and audit tenure on earnings management of companies in the STOXX Europe 600 Index. Practical implications of this study will not also prove whether companies in STOXX Europe 600 Index should be required to shorten their audit tenure by rotating their audit engagement more often in order to decline the degree of earnings management, but they will also help to strengthen support for the essentiality of MAR legislations in the EU if the result indicates that longer audit tenure actually leads to more earnings management of STOXX Europe 600 Index companies.
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Implementation of the Heinrich Spatial Visualization Test in a Virtual Environment
1-8Views:392A virtual environment was developed for PC and Android to be used with a desktop display and the Gear VR, respectively. The goal with it is to measure and enhance the spatial skills of people, because the latter can be achieved by solving simple geometric problems. Originally, this virtual environment consisted only of three such tests, namely the Mental Rotation Test, Mental Cutting Test and Purdue Spatial Visualization Test. Measurements were done in the past with these tests, but now the Heinrich Spatial Visualization Test is also included in the virtual environment. In this paper, its implementation and future measurement plan are presented.
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Torsion of Truncated Hollow Spherical Elastic Body
234-240Views:268This paper deals with the torsion of a body of rotation whose shape is a truncated hollow sphere. The material of the truncated hollow sphere is isotropic, homogeneous and linearly elastic. To solve the torsion problem, the theory of torsion of shafts of varying circular cross section is used, which is introduced by Michell and Föppl. Analytical solution is given for the shearing stresses and displacements. A numerical example illustrates the application of the presented solution. The results of the presented numerical example can be used as a benchmark problem to verify the accuracy of the results computed by finite element simulations.
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Analyzing Determinants of Construction Project Resilience and Success in Ethiopia: a Structural Equation Modelling Approach (PLS-SEM)
1-41Views:81The purpose of this study is to investigate the factors that contribute to the success and resilience of construction projects in Ethiopia’s construction industry. A major gap exists in the current literature regarding the empirical validation of the relationships between resilience and success in the Ethiopian construction industry. Data collection was conducted via an online survey between March 8th and May 13th, 2024. PLS-SEM analysis was performed on the survey responses. Results indicate that resilience significantly impacts a project's success. The following are resilience-enabling factors that increase a project's resilience and enhance overall project performance. These are: resilient leadership (taking risks; learning from subordinates; being flexible during decision making); organisational structures (having few direct reports; narrow span of control; job rotation); and project team culture (assign right people for right jobs; recognition or rewarding the team members; team passions for contribution for project success; team trusts); external environment factors (mitigating high inflation effect; managing unstable economy; using appropriate legal enforcement); and risk management practices (communicating frequently; understanding/knowing how to implement risk management practices; integrating risk management practices into routine activities; having enough budget/finance). Success indicators for construction projects include quality, cost, time, safety and customer satisfaction. Therefore, developing resilience-enhancing strategies could greatly increase the effectiveness of construction project performance. The contribution of this study includes empirical evidence from the Ethiopian context, as well as practical recommendations for policymakers and project managers to create customised resilience strategies. The limitations of this study include reliance on self-reported data and convenience sampling in collecting survey responses. Overall, the study emphasizes the importance of resilience in overcoming the challenges of the construction industry in Ethiopia.
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Principles of Three-Dimensional Computer Design for Understanding Impossible Figures
167-173Views:278For a better understanding of the impossible figures, it is advisable to use modern technological means by which the design of the geometry of the models gives a complete understanding of how they are made. Computer-aided 3D design completely solves this problem. That is, on the one hand, the ultimate visual variant of impossible figures is created, on the other hand, there is the possibility for real manipulation, movement, rotation and other models of space. In this study, 3D models of impossible figures are fully constructed, which are applied in the educational process in order to develop logical thinking. The steps of creating 3D geometry using open source software Blender 3D are described in details.
