1,720,952 research outputs found
Evolution, phylogeny and classification of Suctorea (Ciliophora)
No full textThe monograph is concerned with suctorian ciliates. Using the materials collected
and generalizing all literary data available, the author has proposed original hypotheses
of suctorians’ origin and the main regularities of the evolution of the taxa. A new scheme
of phylogeny of Suctorea has also been elaborated. Based on this research a new system
of the class Suctorea, including 4 subclasses, 15 orders, 2 suborders, 41 families and
124 genera, has been proposed
Tile-Based rasterization on an embedded Tile-based MPSoC
No full textGraphics on a computer are often handled by a graphics pipeline. Rasterization is an important stage in this pipeline. It converts the basic elements of computer graphics, triangles, into the basic elements of a screen, pixels. This stage is very computation intensive and has a large memory footprint. The last decade a lot of research has been dedicated to tile-based rasterization. This technique divides an image into smaller images called tiles. These can be stored on a smaller memory, hence reducing the memory footprint of the rasterization process. Several software and hardware implementations of tile-based rasterization exist. They use a single general purpose processor, or make use of multiple specialized cores, such as Graphical Processing Units (GPUs). Although GPUs prove to be very fast in graphical applications, their effectiveness in running other applications is limited. This is a potential drawback in embedded systems where the available resources are very limited. In Embedded Systems typically Multiple Processors are used in a System on Chip, an MPSoC. This work will make a parallelization study to investigate the performance of rasterization on a MPSoC. To perform this study we modify a tile-based rasterizer to make efficient use of multiple embedded processors. This modified rasterizer is used to evaluate the impact of various configurations on the execution time of the rasterizer. For example the size of an image tile, the size of the communication buffer and the number of processors will be varied in our experiments. Increasing the size of an image tile proves to decrease the execution time only to a certain point, after which the execution time will start to increase. Furthermore, using a larger communication buffer increases the load balancing and decreases the execution time. It is concluded that with the right load balancing adding processors to the system will decrease the time needed to rasterize an image.Computer EngineeringComputer EngineeringElectrical Engineering, Mathematics and Computer Scienc
Testing the randomness in the sky-distribution of gamma-ray bursts
No full textWe have studied the complete randomness of the angular distribution of gamma-ray bursts (GRBs) detected by the Burst and Transient Source Experiment (BATSE). Because GRBs seem to be a mixture of objects of different physical nature, we divided the BATSE sample into five subsamples (short1, short2, intermediate, long1, long2) based on their durations and peak fluxes, and we studied the angular distributions separately. We used three methods, Voronoi tesselation, minimal spanning tree and multifractal spectra, to search for non-randomness in the subsamples. To investigate the eventual non-randomness in the subsamples, we defined 13 test variables (nine from the Voronoi tesselation, three from the minimal spanning tree and one from the multifractal spectrum). Assuming that the point patterns obtained from the BATSE subsamples are fully random, we made Monte Carlo simulations taking into account the BATSE's sky-exposure function. The Monte Carlo simulations enabled us to test the null hypothesis (i.e. that the angular distributions are fully random). We tested the randomness using a binomial test and by introducing squared Euclidean distances in the parameter space of the test variables. We concluded that the short1 and short2 groups deviate significantly (99.90 and 99.98 per cent, respectively) from the full randomness in the distribution of the squared Euclidean distances; however, this is not the case for the long samples. For the intermediate group, the squared Euclidean distances also give a significant deviation (98.51 per cent)
Laboratory studies of riming and its relation to ice splinter production.
No full textExperiments have shown that if a supercooled drop is accreted on to a rimer in such a way that it lands on an already frozen smaller droplet then it may develop a protuberance as it freezes, presumably because the heat loss is fairly symmetrical. These protuberances were found in the temperature range -3 to -8oC, and their probability of production reached a maximum at -5 to -6oC of 1 for every 20 drops accreted. Due to the strong parallelism between the conditions required for protuberance production and ice splinter ejection during riming we suggest that the splinters are a result of explosive fragmentation of about 1% of the protuberances formed. This idea is supported by some experimental evidence.- from Author
Delfi-C3 ontvanger voor scholieren
No full textElectrical Engineering, Mathematics and Computer Scienc
Laboratory studies of riming and its relation to ice splinter production.
No full textExperiments have shown that if a supercooled drop is accreted on to a rimer in such a way that it lands on an already frozen smaller droplet then it may develop a protuberance as it freezes, presumably because the heat loss is fairly symmetrical. These protuberances were found in the temperature range -3 to -8oC, and their probability of production reached a maximum at -5 to -6oC of 1 for every 20 drops accreted. Due to the strong parallelism between the conditions required for protuberance production and ice splinter ejection during riming we suggest that the splinters are a result of explosive fragmentation of about 1% of the protuberances formed. This idea is supported by some experimental evidence.- from Author
Company Interview: An interview with Gleb Vdovin, founder of Flexible Optical BV
No full textFlexible Optical BV is a company that has gathered some fame from the TV-show Discovery’s Project Earth, where they researched a membrane that breaks light in multiple beams. A membrane which is less than 300 nanometers thick. The idea of that project was to prevent the earth from getting too much solar energy. The membranes worked, but the journey to space was not successful.Electrical Engineering, Mathematics and Computer Scienc
Electro: A new aproach to an old game
No full textIn life it’s all about choices. No, you are not about to read a philosophical article about metaphysics. Although it would be interesting to give an overview of determinism from an Electrical Engineer’s point of view, this article is about a board game all (Dutch) electrical engineers like and how to modify it into an even better version.Electrical Engineering, Mathematics and Computer Scienc
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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