Transistor-Level Simulations of Polymorphic Circuits

Tato práce se zabývá problematikou polymorfních obvodů, jejich simulací a zhodnocením dosažených výsledků. Je zde popsána technologie unipolárních  tranzistorů spolu s jednoduchým a názorným návodem pro modelování obvodů v programu OrCAD PSpice. Na závěr jsou uvedeny výsledky simulací pro základní typy hradel.This Bachelor's thesis deals with polymorfic circuits their simulations and evaluations. It describes them unipolar transistors technology and a tool for modely and simulations of electronic circuits - OrCAD PSpice. Finally, the thesis present to results of polymorfic circuits simulations in different conditions.

MORPHOMETRIC TERRAIN ANALYSIS TO EXPLORE PRESENT DAY GEOHAZARDS AND PALEOLANDSCAPE FORMS AND FEATURES IN THE SURROUNDINGS OF THE MELKA KUNTURE PREHISTORIC SITE, UPPER AWASH VALLEY, CENTRAL ETHIOPIA

Morphometric Terrain Analysis was successfully applied in different sectors of environmental studies. However, other disciplines, such as archaeology, might also profit from spatially distributed high-resolution terrain information. In this paper, we show how detailed topographic analysis and simple hydrological modelling approaches help to explain complex terrain pattern and to assess geohazards affecting archaeological sites. We show that Melka Kunture, a cluster of Pleistocene sites in the Upper Awash valley of Ethiopia, is affected by flooding and erosion/sedimentation processes. Moreover, we identified paleo-landscape features, such as changes in drainage pattern and evidences of tectonic activity. The topographic indices indicate especially a different paleo-drainage pattern with a lake or palustrine environment in the upstream areas. Furthermore, a different drainage of the paleo-lake via the Atabella tributary is likely and might be also stressed by the dimensions of the lower Atabella valley with quite large cross sections not corresponding to the present-day drainage situation

Geomorphological processes, forms and features in the surroundings of the Melka Kunture Palaeolithic site, Ethiopia

The landscape of the surroundings of the Melka Kunture prehistoric site, Upper Awash Basin, Ethiopia, were studied intensively in the last decades. Nonetheless, the area was mainly characterized under a stratigraphic/geological and archaeological point of view. However, a detailed geomorphological map is still lacking. Hence, in this study, we identify, map and visualize geomorphological forms and processes. The morphology of the forms, as well as the related processes, were remotely sensed with available high-resolution airborne and satellite sources and calibrated and validated through extensive field work conducted in 2013 and 2014. Furthermore, we integrated multispectral satellite imagery to classify areas affected by intensive erosion processes and/or anthropic activities. The Main Map at 1:15,000 scale reveals structural landforms as well as intensive water-related degradation processes in the Upper Awash Basin. Moreover, the map is available as an interactive WebGIS application providing further information and detail (www.roceeh.net/ethiopia_ geomorphological_map/)

Influence of climate and non-climatic attributes on declining glacier mass budget and surging in Alaknanda Basin and its surroundings

Globally glaciers are rapidly shrinking, endangering the sustainability of melt water and altering the regional hydrology. Understanding long-term glacier response to climate change and the influence of non-climatic attributes like morpho-topographic factors on ice loss is of high relevance. Here we estimate the multi-temporal mass balance of 445 glaciers in the upper Alaknanda basin and neighboring transboundary glaciers using optical stereo imageries from 1973 to 2021. Our measurements indicate a mean annual area change rate of −1.14 ± 0.07 km2 a−1 and a geodetic glacier mass balance of −0.34 ± 0.08 m w.e. a−1 from 1973 to 2020, leading to an overall mass loss of 12.9 ± 1.7 Gt, that accounts for up to 0.036 ± 0.006 mm of sea level rise. Before 2000 (1973–2000), the mean regional glacier mass loss rate was −0.30 ± 0.07 m w.e. a−1, which increased to −0.43 ± 0.06 m w.e. a−1 during 2000–2020. ERA5 Land reanalysis data showed a summer and annual temperature rise of ∼0.6 °C and ∼ 0.5 °C respectively in recent time period (2015–2020) and consequent strong mass loss (−0.68 ± 0.09 m w.e. a−1). In addition to climatic influence, glacier morphometry, topographic features and uneven debris cover distribution further impacted the regional and glacier specific mass balance. Our multi-temporal observation from space also emphasized that though the glaciers in this region experienced an increasing mass loss but a strong heterogeneous glacier specific response, like surging and dynamic separation of glacier, are also evident that was not captured by the available long-term global elevation change grids. Among all the climatic and non-climatic attributes, we identified summer temperature having most significant influence over glacier mass budget in this region, with a mass balance sensitivity of −0.6 m w. e. a−1 °C−1. Hence, knowing the mean summer temperature will help to predict the mass balance for any intermediate year for this region. If such climatic trend continues, smaller glaciers are likely to disapear in coming decades. Similar studies in other parts of the world and on specific glaciers can reveal links with climate factors, reconstruct mass balance, and enhance comprehension of glacier response to climate change. Our geodetic mass balance estimates will improve the estimation of meltwater run-off component of the hydrological cycle in this part of the Himalaya, which could be used to calibrate/validate glacier mass balance models

A novel approach for the representation of multispectral samples in a planar pentagon plot

Graphic representation of multispectral samples in remote sensing is usually limited to single-band histograms or red-infrared scattergrams reflecting the importance of these two spectral bands for vegetation studies. Here a novel straightforward method of graphic representation of five bands in two-dimensional space, a pentagon plot is proposed, in which spectral bands are assigned to vertexes of the pentagon. Each multispectral sample is represented by a set of vectors pointing towards the respective vertices with their starting point in the centre of the pentagon. The magnitude of the vectors is given by reflectance values. The position of the sample in the plot is determined by vector addition. This is followed by scaling in the radial direction to achieve a better distribution of points in the plot area. The potential of a pentagon plot to analyse the content of a multispectral dataset is explored with examples of different sites using Sentinel-2 data. Different surface classes appear as distinct patches in the plot while gradients such as an increase in the amount of vegetation or suspended particles in water bodies are represented by localized curves in the plot. Furthermore, the use of the pentagon plot for quick characterisation of a satellite image, based on randomly selected points, is proposed