The article deals with a research of acoustic emission induced by electromagnetic field. Experiments were focused on measurement of acoustic emission (sound waves) as a mechanical response to the excitation current. Surface displacement was detected by laser interferometer and arising surface waves were then observed. Maximal measured amplitude of mechanical displacement driven by excitation current with amplitude 120 mA is about 8 nm. and Článek se zabývá výzkumem akustické emise generované pomocí elektromagnetického pole. V experimentech se měří velikost mechanické odezvy akustické emise (mechanických vln) na budicí proud z generátoru. Výchylka povrchu byla snímána laserovým interferometrem, byla registrována přítomná povrchová vlna. Maximální amplituda výchylky je 8 nm při amplitudě budicího proudu 120 mA.
This work presents new application of the random field theory in medical imaging. Results from both integral geometry and random field theory can be used to detect locations with significantly increased radiotracer uptake in images from positron emission tomography (PET). The assumptions needed to use these results are verified on a set of real and simulated phantom images. The proposed method of detecting activation (locations with increased radiotracer concentration) is used to quantify the quality of simulated PET images. Dependence of the quality on the injection dose (amount of applied radiotracer) and patient's body parameters is estimated. It is used to derive curves of constant quality determining the injection dose needed to achieve desired quality of the resulting images. The curves are compared with the formula currently used in medical practice.
In the present paper we consider the problem of fitting parametric spatial Cox point process models. We concentrate on the moment estimation methods based on the second order characteristics of the point process in question. These methods represent a simulation-free faster-to-compute alternative to the computationally intense maximum likelihood estimation. We give an overview of the available methods, discuss their properties and applicability. Further we present results of a simulation study in which performance of these estimating methods was compared for planar point processes with different types and strength of clustering and inter-point interactions.
This article deals with the numerical simulation of intensity distribution of the magnetic field by means of the final elements method (FEM). The computational model describes the distribution normal and tangential components of magnetic field intensity at the front and the close vicinity of the front of the external probe of the method of the magnetic spot. The maximum value of the normal component of remanent intensity is 330 kAm-1 when the probe is placed at a distance of 2 mm from the surface. The maximum value of the tangential component of remanent intensity is 230 kAm-1 when the probe is placed at a distance of 2 mm from the material surface. The intensity values were achieved with a maximum current amplitude of 6.91 A. The calculation was determined of the shape and topography of magnetic spot, which will enable the optimisation of measurement. and Článek se zabývá numerickou simulací rozložení intensity magnetického pole pomocí metody konečných prvků. Výpočtový model popisuje rozložení normálové a tangenciální složky intensity magnetického pole metody magnetické skvrny pod čelem příložné sondy. Maximální hodnota normálové složky remanentní intensity je 330 kAm-1 ve vzdálenosti sondy 2 mm nad povrchem materiálu. Maximální hodnota tangenciální složky remanentní intensity je 230 kAm-1 ve vzdálenosti 2 mm nad povrchem materiálu. Hodnoty intensity byly simulovány pro maximální amplitudu proudu 6,91 A. Výpočet směřoval ke zjištění tvaru a topografie magnetické skvrny, které budou sloužit k optimalizaci měření.
The mobile robot path planning involves finding the shortest and least difficult path from a start to a goal position in a given environment without collisions with known obstacles.
The main idea of case-based reasoning (CBR) is a presumption that similar tasks probably also have similar solutions. New tasks are solved by adapting old proved solutions of similar tasks to new conditions. Tasks and their solutions (cases) are stored in a case base.
The focal point of this paper is the proposition of a path planning method based on CBR combined with graph algorithms in the environment represented by a rectangular grid. On the basis of the experimental results obtained, it is possible to say that case-based reasoning can significantly save computation costs, particularly in large environments. and Obsahuje seznam literatury