Interactions between WLAN networks

Tato práce se zabývá vzájemným ovlivňováním WLAN sítí. Vysvětluje historii a následný vývoj bezdrátových technologií a poté se zaměřuje na současné WLAN sítě. Popisuje problematiku rušení ve WLAN sítích a parametry, které nedílnou součástí přispívají k vzájemnému rušení. Součástí práce je vypracování dvou laboratorních úloh. První úloha je realizována v programu Riverbed, ve kterém je sestavena topologie se třemi stejnými WLAN routery. Po otestování WLAN routerů je zobrazen graf popisující rušení v pásmu 2,4 GHz, kterého je dosaženo vhodným zvolením frekvenčního pásma, vysílacího výkonu a kanálu. Druhá laboratorní úloha je realizována v programu Iperf3, který je nainstalovaný na třech Raspberry Pi (RPi Zero, RPi 3 a RPi 4). Zahlcení sítě je docíleno pomocí skriptu wifijammer, který je nainstalován na RPi 4. V této druhé laboratorní úloze byly nejdříve ověřeny parametry přenosu a pomocí skriptu wifijammer byla odmítnuta služba. Pro testování druhé laboratorní úlohy byly zvoleny standardy IEEE 802.11b a IEEE 802.11n s ve frekvenčním pásmu 2,4 GHz. Testování probíhalo na routrech Mercusys, Netis, Tp-Link a Asus. Výsledky z testovacích scénářů byly přehledně zpracovány formou grafů.This bachelor thesis deals with the possible interferences caused by the parallel running WLAN networks. It explains the history and subsequent development of wireless technologies and then focuses on current WLAN networks. It describes the problem of interference in WLAN networks and parameters that contribute to mutual interference. Practical part of this thesis consists of two laboratory exercises. The first task is implemented in the Riverbed program, in which a topology with three identical WLAN routers is assembled. After testing the WLAN routers, a graph describing the interference in the 2.4 GHz band is displayed, which is achieved by a suitable choice of frequency band, transmission power and channel. The second laboratory task is implemented utilizing the Iperf3 program, which is installed on three Raspberry Pi´s (RPi Zero, RPi 3, and RPi 4). Network congestion is achieved using the wifijammer script, which is installed on RPi 4. In this second laboratory task, the transmission parameters were first verified and the service was denied using the wifijammer script. For evaluation of the second laboratory task, the IEEE 802.11b and IEEE 802.11n utilizing the frequency band 2,4 GHz were chosen. For testing, the following routers were used: Mercusys, Netis, Tp-Link and Asus routers. Once the measurements were over, all the data was processed and included as charts.

Thinking of Russia : Finnish Neutrality after the Cold War and the Influence of Russian Neighborhood on Finnish Cooperation with NATO

In recent years, Finland has closely cooperated with NATO and Finnish politicians emphasize that Finland may consider joining the Alliance at any point. However, this step is unlikely in the foreseeable future. Russia’s aggressive actions abroad disconcert Finland; as this article shows, even after Russia’s war with Georgia and the breakout of the crisis in Ukraine, the situation is not deemed serious enough by the Finns for them to risk a serious deterioration of relations with their eastern neighbor. Rather than crossing the interests of Moscow, whose perception of the world Finland has been able uniquely to understand thanks to its historical experience, the country opts for a more complex, yet also safer, path of balancing between ever-closer cooperation with NATO, and maintaining the status of a non-member country

Cell-based and multi-omics profiling reveals dynamic metabolic repurposing of mitochondria to drive developmental progression of Trypanosoma brucei

Mitochondrial metabolic remodeling is a hallmark of the Trypanosoma brucei digenetic life cycle because the insect stage utilizes a cost-effective oxidative phosphorylation (OxPhos) to generate ATP, while bloodstream cells switch to aerobic glycolysis. Due to difficulties in acquiring enough parasites from the tsetse fly vector, the dynamics of the parasite’s metabolic rewiring in the vector have remained obscure. Here, we took advantage of in vitro–induced differentiation to follow changes at the RNA, protein, and metabolite levels. This multi-omics and cell-based profiling showed an immediate redirection of electron flow from the cytochrome-mediated pathway to an alternative oxidase (AOX), an increase in proline consumption, elevated activity of complex II, and certain tricarboxylic acid (TCA) cycle enzymes, which led to mitochondrial membrane hyperpolarization and increased reactive oxygen species (ROS) levels. Interestingly, these ROS molecules appear to act as signaling molecules driving developmental progression because ectopic expression of catalase, a ROS scavenger, halted the in vitro–induced differentiation. Our results provide insights into the mechanisms of the parasite’s mitochondrial rewiring and reinforce the emerging concept that mitochondria act as signaling organelles through release of ROS to drive cellular differentiation

A platform for efficient genotyping in Musa using microsatellite markers

Establishment of a standardized platform for genotyping banana (Musa spp.) using a set of previously published SSR markers is described. The platform will serve a broad Musa research and breeding community and support the conservation and use of genetic diversity

Molecular and cytological characterization of the global Musa germplasm collection provides insights into the treasure of banana diversity

© 2016, The Author(s). Bananas (Musa spp.) are one of the main fruit crops grown worldwide. With the annual production reaching 144 million tons, their production represents an important contribution to the economies of many countries in Asia, Africa, Latin-America and Pacific Islands. Most importantly, bananas are a staple food for millions of people living in the tropics. Unfortunately, sustainable banana production is endangered by various diseases and pests, and the breeding for resistant cultivars relies on a far too small base of genetic variation. Greater diversity needs to be incorporated in breeding, especially of wild species. Such work requires a large and thoroughly characterized germplasm collection, which also is a safe depository of genetic diversity. The largest ex situ Musa germplasm collection is kept at the International Transit Centre (ITC) in Leuven (Belgium) and currently comprises over 1500 accessions. This report summarizes the results of systematic cytological and molecular characterization of the Musa ITC collection. By December 2015, 630 accessions have been genotyped. The SSR markers confirmed the previous morphological based classification for 84% of ITC accessions analyzed. The remaining 16% of the genotyped entries may need field verification by taxonomist to decide if the unexpected classification by SSR genotyping was correct. The ploidy level estimation complements the molecular data. The genotyping continues for the entire ITC collection, including newly introduced accessions, to assure that the genotype of each accession is known in the largest global Musa gene bank. Open Access ispartof: Biodiversity and Conservation vol:26 issue:4 pages:801-824 status: publishe

Preparing high school students for the university studies in the area of natural science

This bachelor thesis focuses on issues and aspects of science education in secondary schools. The theoretical section describes available options for selecting appropriate teaching methods, including additional student activities such as Olympiads and student research projects. The language skills of high school students are also analyzed. The practical section describes a conducted exploratory probe focused on finding information about the knowledge of high school students on student research and professional activities, Olympiads, and their opinion on the importance of these activities for the University entrance examination. Finally, the listed requirements of selected universities to study applicants are discussed

The effect of temperature on the charging and discharging characteristics of lithium-ion batteries

This thesis deals with operation principles of lithium-ion batteries, its degradation principles, capacity fade, materials used, formats, main characteristics, development, uses and mid to high temperature behaviour. The thesis aims to study aging characteristics of commercially available lithium-ion batteries. In the practical part of the thesis, the key parameters of selected types of commercially available lithium-ion batteries were measured under normal temperature conditions. The measurement was repeated at an elevated temperature. Results were analysed and effects of different temperatures on the selected characteristics were concluded both verbally and graphically. A conclusion evaluates short-term and long-term impacts of ambient temperature on rate capability, ageing, capacity fade and longevity

Evaluace www stránek vybraných municipalit

This paper establishes ground for the redesign of Brno-střed city district web page. For the purpose of this study web pages of several municipalities were evaluated: Brno-střed city district, Nové Město na Moravě, Praha 1 and Plzeň. Study shows how the selected municipalities fulfill the legal regulations of the Act no. 106/1999 on free access to information and the Act no. 81/2006 Coll. which states that municipalities are obligated to provide the information on web pages also to handicapped or disabled. Furthermore the usability analysis and quantitative survey were applied to municipality web page in Brno-střed region to determine the public needs and requirements. Presented findings indicate both significant failure in fulfilling the law and public dissatisfaction with Brno-střed web page content and structure. This dissertation provides sample solutions for web page usability