Errors of diffusion measurements for MRI

Bakalářská práce se ve svém úvodu věnuje zobrazovacím a diagnostickým technikám na bázi magnetické rezonance. Nukleární magnetická rezonance patří v dnešní době k uznávaným metodám zkoumání molekul nejrůznějších látek. Především díky více-intervalovým spin-echovým metodám PFGSE. V další části práce je tato spin-echo pulzní sekvence simulována pomocí programu Matlab. Jsou prováděny především simulace ovlivňující chybné měření b-faktoru a difúze. Tyto simulace mohou pomoci předejít výskytu chyb u jiných experimentů.The Bachelor’s thesis is, at it’s begining, focused on the imaging and diagnostic techniques based on principles of magnetic resonance imaging. Nowadays, nuclear magnetic resonance belongs to reputable examing methods of variable molecule matters. Especially, due to multiinterval spin-echo PFGSE methods. Further in this thesis is spin-echo pulse sequence simulated in the data processing computer program Matlab. Simulations influencing error measurement of b-factor and diffusion are performed. These simulations could help to prevent appearance of measurement errors at some other experiments.

Power line parameters

Diplomová práce se v první části věnuje měření primárních parametrů silnoproudých vedení a zkoumání jejich změn při použití různých druhů kabelů. Na základě měření je v druhé části vytvořen komunikační systém v programu Matlab & Simulink, kde jsou prováděny simulace s použitím silnoproudého přenosového vedení. Silnoproudé vedení je vytvořeno pomocí změřených primárních parametrů nebo fyzických rozměrů kabelů a je určena chybovost komunikačního systému při modifikaci jeho jednotlivých částí v závislosti na délce přenosového vedení.At the beginning is diploma thesis focused on a distribute power line parameters measurement and examination changes of this parameters depending on using of various power line cables. On the basis of measurements is made a transmission channel in Matlab & Simulink, where are executed simulations with power transmission line. The simulated power line is based on measured distribute parameters or physical proportions of cabels. By changing different parts of simulated communication channel is a symbol error rate expressed on the lenght of transmission line.

Scrambling is Necessary but Not Sufficient for Chaos

We show that out-of-time-order correlators (OTOCs) constitute a probe for Local-Operator Entanglement (LOE). There is strong evidence that a volumetric growth of LOE is a faithful dynamical indicator of quantum chaos, while OTOC decay corresponds to operator scrambling, often conflated with chaos. We show that rapid OTOC decay is a necessary but not sufficient condition for linear (chaotic) growth of the LOE entropy. We analytically support our results through wide classes of local-circuit models of many-body dynamics, including both integrable and non-integrable dual-unitary circuits. We show sufficient conditions under which local dynamics leads to an equivalence of scrambling and chaos.Comment: 6+16 Pages. Comments welcom

Newly identified climatically and environmentally significant high-latitude dust sources

Peer reviewe

Newly identified climatically and environmentally significant high-latitude dust sources

Dust particles from high latitudes have a potentially large local, regional, and global significance to climate and the environment as short-lived climate forcers, air pollutants, and nutrient sources. Identifying the locations of local dust sources and their emission, transport, and deposition processes is important for understanding the multiple impacts of high-latitude dust (HLD) on the Earth\u27s systems. Here, we identify, describe, and quantify the source intensity (SI) values, which show the potential of soil surfaces for dust emission scaled to values 0 to 1 concerning globally best productive sources, using the Global Sand and Dust Storms Source Base Map (G-SDS-SBM). This includes 64 HLD sources in our collection for the northern (Alaska, Canada, Denmark, Greenland, Iceland, Svalbard, Sweden, and Russia) and southern (Antarctica and Patagonia) high latitudes. Activity from most of these HLD sources shows seasonal character. It is estimated that high-latitude land areas with higher (SI ≥0.5), very high (SI ≥0.7), and the highest potential (SI ≥0.9) for dust emission cover >1 670 000 km$^{2}$, >560 000 km$^{2}$, and >240 000 km$^{2}$, respectively. In the Arctic HLD region (≥60$^{∘}$ N), land area with SI ≥0.5 is 5.5 % (1 035 059 km$^{2}$), area with SI ≥0.7 is 2.3 % (440 804 km$^{2}$), and area with SI ≥0.9 is 1.1 % (208 701 km$^{2}$). Minimum SI values in the northern HLD region are about 3 orders of magnitude smaller, indicating that the dust sources of this region greatly depend on weather conditions. Our spatial dust source distribution analysis modeling results showed evidence supporting a northern HLD belt, defined as the area north of 50$^{∘}$ N, with a “transitional HLD-source area” extending at latitudes 50–58∘ N in Eurasia and 50–55$^{∘}$ N in Canada and a “cold HLD-source area” including areas north of 60$^{∘}$ N in Eurasia and north of 58$^{∘}$ N in Canada, with currently “no dust source” area between the HLD and low-latitude dust (LLD) dust belt, except for British Columbia. Using the global atmospheric transport model SILAM, we estimated that 1.0 % of the global dust emission originated from the high-latitude regions. About 57 % of the dust deposition in snow- and ice-covered Arctic regions was from HLD sources. In the southern HLD region, soil surface conditions are favorable for dust emission during the whole year. Climate change can cause a decrease in the duration of snow cover, retreat of glaciers, and an increase in drought, heatwave intensity, and frequency, leading to the increasing frequency of topsoil conditions favorable for dust emission, which increases the probability of dust storms. Our study provides a step forward to improve the representation of HLD in models and to monitor, quantify, and assess the environmental and climate significance of HLD

XXV. mezinárodní kolokvium o regionálních vědách

Title in English: 25th International Colloquium on Regional Sciences: Conference proceedings The conference proceedings consists of papers presented at the 25th International Colloquium on Regional Sciences that was organized by Department of Regional Economics and Administration FEA MU. It contains 57 articles arranged by topic. The individual articles deal with e.g. socioeconomic disparities among regions, regional policy, territory attractiveness, tourism, or regional public administration

Power line parameters

At the beginning is diploma thesis focused on a distribute power line parameters measurement and examination changes of this parameters depending on using of various power line cables. On the basis of measurements is made a transmission channel in Matlab & Simulink, where are executed simulations with power transmission line. The simulated power line is based on measured distribute parameters or physical proportions of cabels. By changing different parts of simulated communication channel is a symbol error rate expressed on the lenght of transmission line