[dipl] Perustieteiden korkeakoulu / SCI

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Browsing [dipl] Perustieteiden korkeakoulu / SCI by Subject "2D"

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  • Modelling Neuronal Network Dynamics: The Effect of Two- and Three-Dimensional Topology
    (2014) Vornanen, Inkeri
     Perustieteiden korkeakoulu | Master's thesis
    Neurons form in their natural environment three-dimensional structures. However, most of the in vitro cultures of neurons have been planar. This study aimed to construct a simulation model of a neuronal network to predict, how the network dynamics change, as the neuronal network is transformed from 2D to 3D. We based our model on two biologically realistic computational neuronal network models from literature. Neither of the network models had spatial topology, so in this work we added simple 2D and 3D topologies to the model: First the neurons were placed randomly in 2D or 3D space and then connected to the nearest neurons. The resulting network was approximately 10 %-connected. For comparisons, we used also a non-topological model network, where the neurons were connected randomly. We compared the bursting behaviour of our simulation model in 2D and 3D to in vitro neuronal networks consisting of human embryonic stem cell (hESC) derived neurons. We used data measured with microelectrode arrays (MEAs), which record the electrical activity of the neuron culture at multiple locations simultaneously. The model was compared with planar cultures only, because the 3D neuronal culturing and measurement systems are still in development. The behaviour of the 2D model network was similar to that of the biological neuronal networks when compared visually and statistically. Our simulations illustrated also that adding the topology increased the activity of the network: the spikes and bursts were more frequent in the both 2D and 3D networks than in networks without topology. Also, 3D networks were more active than 2D networks. The very simple topological model used in the study was able to induce a change in the network behaviour, which suggests that spatial topology has an important role in the neuron network dynamics, and encourages us to improve the topology model towards a more biologically plausible one for more realistic results.
  • Redesigning a 2D graphics toolkit
    (2010) Sydänmaanlakka, Kari
     School of Science | Master's thesis
    During the recent years the technological evolution of the computer hardware has been rapid. The evolution has enabled the development of high performing graphics rich applications. As these kinds of applications have become mainstream and more available, also the need to he able to provide similar performance and rich graphics for the users of the applications that Tekla Corporation develops have increased. This thesis describes the design and implementation of a 2D graphics toolkit prototype, which was implemented during this work. The implemented prototype aims to be able to provide this capability for the Tekla applications. This thesis is divided into two parts. The first part provides the necessary background information, starting with the description of the Tekla applications, the other related software components, and the key concepts involved. After this, information on the currently available technology, its trends, and relevant software is provided. The second part discusses the prototype implementation. Within the implementation, the problem is approached by first comparing and evaluating the needs to the existing graphics toolkit. In the next step the various available graphics APIs are compared and their relative performance is studied. After that, the design and implementation of the new graphics toolkit prototype, which was implemented during this work, is described. In the following steps, the utilization of parallelization within the prototype toolkit is discussed, and a method for providing additional graphics for the implemented high performance graphics system is provided. Finally an analysis of this work and projections on future work are provided.