163 research outputs found
Traveling Salesman Problem - Serial Methods
Tato bakalářská práce popisuje některé algoritmy, které řeší problém obchodního cestujícího pomocí sekvenčního přístupu. Dále se zabývá analýzou efektivnosti a škálovatelnosti řešení tohoto problému.This bachelor's thesis describes some algorithm which solves traveling salesman problem by the help of serial methods. This thesis deals with efficiency analysis and scalability of this problem.
Point Information Gain and Multidimensional Data Analysis
We generalize the Point information gain (PIG) and derived quantities, i.e.
Point information entropy (PIE) and Point information entropy density (PIED),
for the case of R\'enyi entropy and simulate the behavior of PIG for typical
distributions. We also use these methods for the analysis of multidimensional
datasets. We demonstrate the main properties of PIE/PIED spectra for the real
data on the example of several images, and discuss possible further utilization
in other fields of data processing.Comment: 16 pages, 6 figure
Implementation of Statistical Compression Methods
Tato diplomová práce popisuje Burrowsův-Wheelerův kompresní algoritmus. Detailně se zaměřuje na jednotlivé části Burrowsova-Wheelerova algoritmu, nejvíce na transformaci globální struktury a entropické kódery. V rámci transormace globální struktury jsou popsány například tyto metody presuň na začátek, inverzní frekvence, intervalové kódování a další. Mezi popsanými entropickými kodéry jsou Huffmanovo, aritmetické a Riceovo-Golombovo kódování. V závěru je provedeno testování metod transformace globální struktury a entropických kodérů. Nejlepší kombinace je porovnána s nejpoužívanějšími kompresními algoritmy.This thesis describes Burrow-Wheeler compression algorithm. It focuses on each part of Burrow-Wheeler algorithm, most of all on and entropic coders. In section are described methods like move to front, inverse frequences, interval coding, etc. Among the described entropy coders are Huffman, arithmetic and Rice-Golomg coders. In conclusion there is testing of described methods of global structure transformation and entropic coders. Best combinations are compared with the most common compress algorithm.
Productin of injector holder
Práce předkládá návrh postupu výroby upínací matice pomocí protlačování za studena. Matice, vyrobená z materiálu ČSN 12 050, slouží k upnutí vstřikovací trysky ke vstřikovacímu ústrojí. Dále jsou zpracovány varianty výroby, z nichž byla vybrána varianta B, u které jako polotovar byla zvolena tyč o průměru 24 mm s tolerancí f9 od firmy Ferona a. s. Pro tuto variantu byly vyhotoveny výpočty procesních parametrů, na jejichž základě byl vybrán postupový tvářecí automat TPD 630 se jmenovitou sílou 6 000 kN. Pro zvolený stroj byly navrženy nástroje pro jednotlivé tvářecí operace, jejichž geometrie je uvedena ve výkresové dokumentaci. Na základě technicko-ekonomického zhodnocení byla stanovena výsledná cena tvářené součásti na 18,48 Kč.This paper presents a design of the production process for the clamping nut by cold extrusion. The nut, which is made of material ČSN 12 050, is used to clamp the injection nozzle to the injection system. Subsequently different variants of production were processed, from which the variant B was chosen. For slug a rod with diameter size of 24 mm with toleration f9 made by the company Ferona a. s was chosen. Calculations of process parameters were made for this variant. Based on the parameters the automatic forming machine TPD 630 with nominal force of 6 000 kN was chosen. For the selected machine, operational tools were designed for each forming operation, whose geometry is shown in the drawing documentation. Based on the technical and economical evaluation, the final price of the formed part was set at CZK 18,48.
OPTIMIZATION OF COMPUTATIONAL BURDEN OF THE POINT INFORMATION GAIN
We developed a method of image preprocessing based on the information entropy, namely, on the information contribution made by each individual pixel to the whole image or to image’s part (i.e., a Point Information Gain; PIG). An idea of the PIG calculation is that an image background remains informatively poor, whereas objects carry relevant information. In one calculation, this method preserves details, highlights edges, and decreases random noise. This paper describes optimization and implementation of the PIG calculation on graphical processing units (GPU) to overcome a high computational burden
OPTIMIZATION OF COMPUTATIONAL BURDEN OF THE POINT INFORMATION GAIN
We developed a method of image preprocessing based on the information entropy, namely, on the information contribution made by each individual pixel to the whole image or to image’s part (i.e., a Point Information Gain; PIG). An idea of the PIG calculation is that an image background remains informatively poor, whereas objects carry relevant information. In one calculation, this method preserves details, highlights edges, and decreases random noise. This paper describes optimization and implementation of the PIG calculation on graphical processing units (GPU) to overcome a high computational burden
Measurement in biological systems from the self-organisation point of view
Measurement in biological systems became a subject of concern as a
consequence of numerous reports on limited reproducibility of experimental
results. To reveal origins of this inconsistency, we have examined general
features of biological systems as dynamical systems far from not only their
chemical equilibrium, but, in most cases, also of their Lyapunov stable states.
Thus, in biological experiments, we do not observe states, but distinct
trajectories followed by the examined organism. If one of the possible
sequences is selected, a minute sub-section of the whole problem is obtained,
sometimes in a seemingly highly reproducible manner. But the state of the
organism is known only if a complete set of possible trajectories is known. And
this is often practically impossible. Therefore, we propose a different
framework for reporting and analysis of biological experiments, respecting the
view of non-linear mathematics. This view should be used to avoid
overoptimistic results, which have to be consequently retracted or largely
complemented. An increase of specification of experimental procedures is the
way for better understanding of the scope of paths, which the biological system
may be evolving. And it is hidden in the evolution of experimental protocols.Comment: 13 pages, 5 figure
The Complete Mitochondrial Genome and Novel Gene Arrangement of the Unique-Headed Bug Stenopirates sp. (Hemiptera: Enicocephalidae)
Many of true bugs are important insect pests to cultivated crops and some are important vectors of human diseases, but few cladistic analyses have addressed relationships among the seven infraorders of Heteroptera. The Enicocephalomorpha and Nepomorpha are consider the basal groups of Heteroptera, but the basal-most lineage remains unresolved. Here we report the mitochondrial genome of the unique-headed bug Stenopirates sp., the first mitochondrial genome sequenced from Enicocephalomorpha. The Stenopirates sp. mitochondrial genome is a typical circular DNA molecule of 15, 384 bp in length, and contains 37 genes and a large non-coding fragment. The gene order differs substantially from other known insect mitochondrial genomes, with rearrangements of both tRNA genes and protein-coding genes. The overall AT content (82.5%) of Stenopirates sp. is the highest among all the known heteropteran mitochondrial genomes. The strand bias is consistent with other true bugs with negative GC-skew and positive AT-skew for the J-strand. The heteropteran mitochondrial atp8 exhibits the highest evolutionary rate, whereas cox1 appears to have the lowest rate. Furthermore, a negative correlation was observed between the variation of nucleotide substitutions and the GC content of each protein-coding gene. A microsatellite was identified in the putative control region. Finally, phylogenetic reconstruction suggests that Enicocephalomorpha is the sister group to all the remaining Heteroptera
Differential Bird Responses to Colour Morphs of an Aposematic Leaf Beetle may Affect Variation in Morph Frequencies in Polymorphic Prey Populations
The selection of prey by predators should, theoretically, favour uniformity in the warning signals displayed by unpalatable prey. Nevertheless, some aposematically coloured species are polymorphic. We tested the hypothesis that colour morphs of unpalatable prey differ in the efficacy of their aposematic signal for birds, thereby affecting the selective advantages of these morphs. We used colour morphs (red-and-black light, red-and-black dark and metallic) of the chemically defended leaf beetle Chrysomela lapponica. In laboratory experiments, naïve great tits (Parus major) attacked live beetles of all colour morphs at the same rate. By contrast, wild-caught tits attacked light beetles at first encounter at the same rate as a novel control prey, but significantly avoided both dark and metallic beetles. Beetles of all colour morphs were similarly unpalatable for birds, and about half of the attacked beetles were released unharmed. Avoidance learning was similarly fast for all three leaf beetle morphs. However, in the next-day memory test, the dark beetles were attacked at a greater rate than beetles of two other morphs, indicating their lower memorability. A field experiment suggests that at low C. lapponica population densities, dark beetles have a survival advantage over light beetles, potentially due to the lesser conspicuousness of the dark pattern; however, when the density is high, dark beetles lose this advantage due to the low memorability of their pattern. Thus, the direction of selective bird predation on prey colour morphs may depend on prey density and thereby contribute to temporal shifts in colour morph frequencies following population fluctuations.</p
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