Podpora fraktur pro jbox2d engine

JBox2D je herní engine simulující fyziku pevných těles a kapalin v 2D pros- toru. Práce poskytuje rozšíření knihovny JBox2D umožňující tříštění těles po je- jich vzájemné kolizi. Důraz je kladen na plynulost činnosti algoritmu v reálném čase, nízké nároky na výkon procesoru a přirozenost průběhu procesů tříštění. Algoritmus také poskytuje možnost definovat materiály těles a nastavovat jejich vlastnosti, na nichž závisí průběh simulace tříštění těchto těles. Je k dispozici jednoduché programátorské rozhraní založené na logice knihovny. Na demons- traci funkčnosti daného řešení práce obsahuje i jednoduchý framework s testo- vacími scénáři napodobujícími fraktury objektů. Práce poskytuje nové možnosti při vývoji 2D her pro mobilní zařízení a osobní počítače. 1JBox2D is a game engine simulating the physics of solid objects and liquids in a 2D space. This project provides a JBox2D library extension that allows for fracturing of objects after their collision. The presented algorithm prioritizes its smooth running in real time, low processing power requirements and a natural flow of the fracturing processes. The algorithm also provides a possibility to define the materials of the objects to be fractured and set their properties, which in turn determine the outcome of the simulation process of fracturing these objects. A simple programming interface based on the logic of the library is provided. In order to demonstrate the usability of the solution, the project also contains a simple framework with test scenarios simulating fracturing of objects. This project provides new possibilities for developing 2D games for mobile devices and personal computers. 1Department of Distributed and Dependable SystemsKatedra distribuovaných a spolehlivých systémůMatematicko-fyzikální fakultaFaculty of Mathematics and Physic

Drift-diffusion models for innovative semiconductor devices and their numerical solution

We present charge transport models for novel semiconductor devices which may include ionic species as well as their thermodynamically consistent finite volume discretization

Dispersion analysis of two-dimensional unstructured transmission line modelling (UTLM)

Numerical simulation techniques play an important role due to their flexibility in dealing with a broad range of complex geometries and material responses. This flexibility requires substantial computational time and memory. Most numerical methods use structured grid for graphical discretization, although this approach is straightforward it is not ideal for smoothly curved boundaries. In this thesis the two-dimensional Transmission Line Modelling (TLM) method based on unstructured meshes is adopted. TLM is an established numerical simulation technique that has been employed in a variety of applications area. Using unstructured meshes to discretize the problem domain permits smooth boundary presentation which provides significant enhancement in the flexibility and accuracy of the TLM simulations. An algorithm is developed to implement Unstructured Transmission Line Modelling (UTLM) which is carefully designed for simplicity and scalability of model size. Several examples are employed to test the accuracy and efficiency of the UTLM simulations. Delaunay meshes, as a type of unstructured meshes, provide good quality triangles but have the disadvantage of providing close to zero transmission line length which has impact on the maximum permissible time step for stable operation. In this thesis, a simple perturbation method for relaxing the minimum link length and clustering triangles in pairs is presented, which permits substantial increase in time step and hence computational runtime to be made without compromising the simulation stability or accuracy. Also, a new model for relaxing the short link lines that fall on the boundaries is presented. UTLM method is based on temporal and spatial sampling of electromagnetic fields which results in dispersion. In this thesis, dispersion characteristics of the unstructured TLM mesh are investigated and compared against structured TLM results for different mesh sizes and shapes. Unlike the structured TLM mesh, the unstructured mesh gives rise to spatial mode coupling. Intermodal coupling behaviour is investigated in a statistical manner upon the change of the mesh local characteristics

Dispersion analysis of two-dimensional unstructured transmission line modelling (UTLM)

Numerical simulation techniques play an important role due to their flexibility in dealing with a broad range of complex geometries and material responses. This flexibility requires substantial computational time and memory. Most numerical methods use structured grid for graphical discretization, although this approach is straightforward it is not ideal for smoothly curved boundaries. In this thesis the two-dimensional Transmission Line Modelling (TLM) method based on unstructured meshes is adopted. TLM is an established numerical simulation technique that has been employed in a variety of applications area. Using unstructured meshes to discretize the problem domain permits smooth boundary presentation which provides significant enhancement in the flexibility and accuracy of the TLM simulations. An algorithm is developed to implement Unstructured Transmission Line Modelling (UTLM) which is carefully designed for simplicity and scalability of model size. Several examples are employed to test the accuracy and efficiency of the UTLM simulations. Delaunay meshes, as a type of unstructured meshes, provide good quality triangles but have the disadvantage of providing close to zero transmission line length which has impact on the maximum permissible time step for stable operation. In this thesis, a simple perturbation method for relaxing the minimum link length and clustering triangles in pairs is presented, which permits substantial increase in time step and hence computational runtime to be made without compromising the simulation stability or accuracy. Also, a new model for relaxing the short link lines that fall on the boundaries is presented. UTLM method is based on temporal and spatial sampling of electromagnetic fields which results in dispersion. In this thesis, dispersion characteristics of the unstructured TLM mesh are investigated and compared against structured TLM results for different mesh sizes and shapes. Unlike the structured TLM mesh, the unstructured mesh gives rise to spatial mode coupling. Intermodal coupling behaviour is investigated in a statistical manner upon the change of the mesh local characteristics