Keresés

Keresési eredmények

• Displacement: Translation and Rotation. Differences and Similarities in the Discrete and Continuous Models

  104-124

  Lámer Géza

  Megtekintések száma:

  116

  The 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.

• The Propensity for Mandatory Audit Rotation and its Impact on Earnings Management in Europe

  222-233

  Reicher Regina

  Bao Ngo Tran Nguyen

  Megtekintések száma:

  251

  The 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.

• A Heinrich Spatial Visualization Test Implementálása Virtuális Környezetben

  1-8

  Guzsvinecz Tibor

  Sik-Lanyi Cecilia

  Orban-Mihalyko Eva

  Perge Erika

  Megtekintések száma:

  181

  Egy virtuális környezet fejlesztése valósult meg PC-re és Androidra. Az előbbit asztali kijelzővel, az utóbbit a Gear VR készülékkel lehet használni. A környezet használatával az emberek térbeli készségeinek mérése, valamint fejlesztése a célunk, hiszen az utóbbi megvalósítható egyszerű geometriai feladatok megoldásával. Eredetileg ez a virtuális környezet csak három térbeli készséget fejlesztő tesztből állt, nevezetesen a Mental Rotation Testből, a Mental Cutting Testből és a Purdue Spatial Visualization Testből. A szerzők már végeztek régebben méréseket ezekkel a tesztekkel, de most már a Heinrich Spatial Visualization Test is bekerült a virtuális környezetbe. Ebben a cikkben bemutatjuk ezen teszttípus implementálását és jövőbeli mérési tervünket.

• Principles of Three-Dimensional Computer Design for Understanding Impossible Figures

  167-173

  Dovramadjiev Tihomir

  Megtekintések száma:

  124

  For 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.

• Üreges csonka gömb alakú rugalmas test csavarása

  234-240

  Ecsedi István

  Lengyel Ákos

  Baksa Attila

  Gönczi Dávid

  Megtekintések száma:

  117

  Jelen kutatás tárgya olyan forgástestek csavarási problémája, melyek alakja üreges csonka gömb. A kérdéses test anyaga homogén, izotrop, lineárisan rugalmas. A csavarási feladat megoldásához a Michell elméletet használjuk fel, mely változó körkeresztmetszetű tengelyek csavarására lett kidolgozva. Analitikus megoldást mutatunk be a nyírófeszültségek és elmozdulások meghatározására. A felírt módszer illusztrálására egy numerikus példát is bemutatunk. A példa eredményei felhasználhatóak, mint benchmark megoldás más numerikus módszerekből, például végeselem módszerből nyert megoldások pontosságának elemzésére.