433 research outputs found
Fuel injector characteristics measurement of spark-ignited engine
Cílem této bakalářské práce je provést rešerši zabývající se problematikou ohledně vstřikování paliva záţehových spalovacích motorů, konkrétně tedy vstřikovacími ventily pro motory s přímým i nepřímým vstřikováním paliva. Další části je provést návrh metodiky a sestrojit zařízení pro provádění testovacích zkoušek zmíněných ventilů.The aim of this work will be to research dealing with issues about the fuel injection petrol engines, in particular fuel injectors for engines with direct and indirect fuel injection.In the next part make a proposal to build a system for implementation of test injection valves.
Segmentation of articular cartilage and early osteoarthritis based on the fuzzy soft thresholding approach driven by modified evolutionary ABC optimization and local statistical aggregation
Articular cartilage assessment, with the aim of the cartilage loss identification, is a crucial task for the clinical practice of orthopedics. Conventional software (SW) instruments allow for just a visualization of the knee structure, without post processing, offering objective cartilage modeling. In this paper, we propose the multiregional segmentation method, having ambitions to bring a mathematical model reflecting the physiological cartilage morphological structure and spots, corresponding with the early cartilage loss, which is poorly recognizable by the naked eye from magnetic resonance imaging (MRI). The proposed segmentation model is composed from two pixel's classification parts. Firstly, the image histogram is decomposed by using a sequence of the triangular fuzzy membership functions, when their localization is driven by the modified artificial bee colony (ABC) optimization algorithm, utilizing a random sequence of considered solutions based on the real cartilage features. In the second part of the segmentation model, the original pixel's membership in a respective segmentation class may be modified by using the local statistical aggregation, taking into account the spatial relationships regarding adjacent pixels. By this way, the image noise and artefacts, which are commonly presented in the MR images, may be identified and eliminated. This fact makes the model robust and sensitive with regards to distorting signals. We analyzed the proposed model on the 2D spatial MR image records. We show different MR clinical cases for the articular cartilage segmentation, with identification of the cartilage loss. In the final part of the analysis, we compared our model performance against the selected conventional methods in application on the MR image records being corrupted by additive image noise.Web of Science117art. no. 86
Approximations of solution concepts of cooperative games
The computation of a solution concept of a cooperative game usually depends
on values of all coalitions. However, in some applications, values of some of
the coalitions might be unknown due to various reasons. We introduce a method
to approximate standard solution concepts based only on partial information
given by a so called incomplete game. We demonstrate the ideas on the class of
minimal incomplete games. Approximations are derived for different solution
concepts including the Shapley value, the nucleolus, or the core. We show
explicit formulas for approximations of some of the solution concepts and show
how the approximability differs based on additional information about the game
Interface Simulation Distances
The classical (boolean) notion of refinement for behavioral interfaces of
system components is the alternating refinement preorder. In this paper, we
define a distance for interfaces, called interface simulation distance. It
makes the alternating refinement preorder quantitative by, intuitively,
tolerating errors (while counting them) in the alternating simulation game. We
show that the interface simulation distance satisfies the triangle inequality,
that the distance between two interfaces does not increase under parallel
composition with a third interface, and that the distance between two
interfaces can be bounded from above and below by distances between
abstractions of the two interfaces. We illustrate the framework, and the
properties of the distances under composition of interfaces, with two case
studies.Comment: In Proceedings GandALF 2012, arXiv:1210.202
Convergence to fractional kinetics for random walks associated with unbounded conductances
We consider a random walk among unbounded random conductances whose distribution has infinite expectation and polynomial tail. We prove that the scaling limit of this process is a Fractional-Kinetics process—that is the time change of a d-dimensional Brownian motion by the inverse of an independent α-stable subordinator. We further show that the same process appears in the scaling limit of the non-symmetric Bouchaud's trap mode
Recent trends, technical concepts and components of computer-assisted orthopedic surgery systems: A comprehensive review
Computer-assisted orthopedic surgery (CAOS) systems have become one of the most important and challenging types of system in clinical orthopedics, as they enable precise treatment of musculoskeletal diseases, employing modern clinical navigation systems and surgical tools. This paper brings a comprehensive review of recent trends and possibilities of CAOS systems. There are three types of the surgical planning systems, including: systems based on the volumetric images (computer tomography (CT), magnetic resonance imaging (MRI) or ultrasound images), further systems utilize either 2D or 3D fluoroscopic images, and the last one utilizes the kinetic information about the joints and morphological information about the target bones. This complex review is focused on three fundamental aspects of CAOS systems: their essential components, types of CAOS systems, and mechanical tools used in CAOS systems. In this review, we also outline the possibilities for using ultrasound computer-assisted orthopedic surgery (UCAOS) systems as an alternative to conventionally used CAOS systems.Web of Science1923art. no. 519
Design of the experimental PV tracker
Cílem této bakalářské práce je navrhnout a sestavit dvouosé zařízení pro polohování fotovoltaického panelu. Dále navrhnout výkresovou dokumentaci ovládací elektrické části a zrealizovat. Výstupem práce je technická dokumentace se seznamem součástí. Práce obsahuje také ekonomické zhodnocení nákladů.The aim of this thesis is to design, show plans and build two devices for positioning the solar panel. The output of the work is a technical documentation with a list and procedure of assembly. The thesis also includes economic cost evaluation.
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