Digital Modulation in Telecommunications

Import 04/07/2011Tématem této práce jsou digitální modulace v telekomunikacích. Řekneme si, co je modulace, dělení na analogové a digitální modulace, kde se zaměříme na typy digitálních modulaci. Popíši amplitudové, frekvenční i fázové klíčování. V další části najdete popis DSL technologií, historický vývoj přes symetrické DSL až po asymetrické. Podrobněji si popíšeme především ADSL. Následně vysvětlím digitální modulace v ADSL. Jsou to CAP modulace, používána do roku 1996 a DMT modulace, která nastoupila na místo CAP a využívá se stále. Praktickou částí je návod na vytvoření vybrané digitální modulace na výukovém stroji TIMS, ve formě laboratorního měření pro studenty, včetně ukázkového protokolu. Praktická část je mnou vytvořena laboratorní práce pro studenty, na výukovém stroji TIMS.The topic in this work is digital modulation in Telecommunications. We will talk about, what is modulation, division on analog and digital modulation, where we focus on digital modulation. I will describe amplitude, frequency and phase shift keying. In second part you will find the describtion of DSL technology, historical evolution from symmetric DSL to asymmetric. I will look in detail on ADSL. Afterwards I will explain digital modulation in ADSL. These are CAP modulation, used till year 1996 and DMT modulation, which takes place instead of CAP, until today. Practical part is guideline on how to create choosen digital modulation on the learning system TIMS in form of laboratory measurement for students, including exemplary protocol.460 - Katedra informatikydobř

Scale Free Network Reduction by Swarm Intelligence

Import 06/11/2014Cílem diplomové práce je vytvořit algoritmus, který zredukuje bezškálový graf použitím rojové inteligence. Za rojovou inteligenci byl v této práci zvolen mravenčí algoritmus. V textu nalezneme postupný vývoj bezškálových grafů, jejich vlastnosti a kapitolu o klasických grafových redukčních technikách, které jsou považovány za současný trend redukcí grafů. Další část se zaměřuje na popis mravenčího algoritmu a návrh implementovaného algoritmu. V experimentální části této práce budou zobrazeny výsledky redukcí grafů pomocí implementovaného mravenčího algoritmu a následně zanalyzovány k posouzení vhodnosti tohoto algoritmu na řešený problém redukce grafů.The diploma thesis is focused on implementation of algorithm, which reduces scale free graphs using swarm inteligennce. For a swarm inteligence in this thesis was choosed ant colony algorithm. In this text you can find evolution of scale free graphs, their properties and a chapter about classic graph reduction techniques, which are considered as a current trend of graph reduction. The next part is focusing on description of ant algorithm and design of implemented algorithm. In experimental part of this thesis there will be presented results of graph reduction using implemented ant algorithm and after that they will be analysed to evaluate suitability of implemented algorithm for solving a problém of graph reduction460 - Katedra informatikydobř

Sampling methods for low-frequency electromagnetic imaging

For the detection of hidden objects by low-frequency electromagnetic imaging the Linear Sampling Method works remarkably well despite the fact that the rigorous mathematical justification is still incomplete. In this work, we give an explanation for this good performance by showing that in the low-frequency limit the measurement operator fulfills the assumptions for the fully justified variant of the Linear Sampling Method, the so-called Factorization Method. We also show how the method has to be modified in the physically relevant case of electromagnetic imaging with divergence-free currents. We present numerical results to illustrate our findings, and to show that similar performance can be expected for the case of conducting objects and layered backgrounds

Food and nutrition status of households with homegardens in the Nuba Mountains of Sudan

Sudan is one of the least developed countries and many people particularly in South Kordofan suffer from food insecurity. Food production from homegardens (HG) and wild collections are seen as key elements in strategies to overcome nutrient deficiencies. Food intake 24h-recalls were conducted to evaluate the status quo of households (HHs) and the contribution from four HG and wild collection during three seasons in Sama in South Kordofan, Sudan. Dietary diversity as well as nutrient intake was determined and food samples were taken. On average people consumed 16 food items belonging to eight food groups, which is adequate or higher than reported in other studies. Mean daily intake was 1438 kcal energy, 36 g protein, 182 μg vitamin A, 23 mg vitamin C, 9 mg iron and 5 mg zinc. This indicates a nutrient deficiency, especially in vitamins. Differences between traditional and commercial (marketoriented) HGs were small. Households which considered HGs to be important for their daily life had a better nutrient intake, but less diverse diet than those with a reduced importance of HGs. Thus the perceived importance of the HGs seemed to affect HH nutrition more than the level of their commercialization. In total twelve food items from HGs (mostly green leafy vegetables, high in vitamin A) and seven from the wild (mainly Ziziphus spina-christi (L.) Willd, high in vitamin C) were used within the three weeks interview period. The results show the importance of the HG to HH´s nutrition and also indicate the importance of wild collection for the dietary status of HH in the Nuba Mountains of Sudan

Systemintegration: eine qualitative Erhebung aus der Sicht von Integrationsdienstleistern

Systemintegration hat auf Grund des Einsatzes heterogener Systeme eine fortlaufende Bedeutung für viele Unternehmen und vor allem für Integrationsdienstleister. Die Praxis der Integration stimmt nicht immer mit den aktuellen Forschungsthemen überein. Diese qualitative Erhebung liefert einen Zustandsbericht über Herausforderungen und Probleme denen Integrationsdienstleister täglich begegnen und dient der Identifikation von praxisrelevanten Forschungsfragen

Possible Development Paths of Tactile Internet: Ethical Perspectives

In this article, we will reflect on the methodologies of ethical technology assessment (TA cf. Grunwald 2010), accompanying research projects focusing on tactile internet solutions with humans in the loop (TaHIL). We outline how TA might be oriented towards a set of prima facie values (Beauchamp & Childress, 2013) that address possible implications and consequences of technology use. This framework shall be applied to the development of tactile Internet technology treating such technology as a special kind of cyber-physical system. Because the impact of technical developments and their unintended consequences cannot be anticipated from the outset, it is all the more important to address ethically relevant aspects right from the start in research projects that develop TaHIL-applications.:1. Aim of the basic research in Technology Assessment 2. TA as an integrative part of the iterative research approach 3. Responsible Research and Innovation: three dimensional Path Developments 4. Dilemmata in the democratization of skills 5. Work systems within the framework of TaHIL technologies 6. Implementation process 7. Conclusio

A sampling method for detecting buried objects using electromagnetic scattering

We consider a simple (but fully three-dimensional) mathematical model for the electromagnetic exploration of buried, perfect electrically conducting objects within the soil underground. Moving an electric device parallel to the ground at constant height in order to generate a magnetic field, we measure the induced magnetic field within the device, and factor the underlying mathematics into a product of three operations which correspond to the primary excitation, some kind of reflection on the surface of the buried object(s) and the corresponding secondary excitation, respectively. Using this factorization we are able to give a justification of the so-called sampling method from inverse scattering theory for this particular set-up

Trilepton Final State from Neutralino-Chargino Production in mSUGRA

The direct production of neutralino-chargino chi^0_2 chi^pm_1 pairs in the mSUGRA scenario with decays into pure trilepton final states has a significant cross section for low neutralino masses. The trilepton signature was studied with the full and fast CMS detector simulations. The 5 sigma signal can be observed in the dilepton invariant mass distribution at the integrated luminosity of L_int>30 fb^-1 for m_1/2 <180 GeV