Models of Control Channels in the LTE System

Dizertační práce se zabývá zpracováním signálu fyzických řídicích kanálů systému LTE a vyšetřováním bitové chybovosti při přenosu řídicí informace z vysílače do přijímače v závislosti na podmínkách příjmu. Práce je rozdělena do dvou hlavních částí. První část práce je zaměřena na simulaci přenosu řídicí informace LTE v základním pásmu. Jsou zde prezentovány vytvořené simulátory řídicích kanálů ve směru uplink i downlink. Simulace jsou provedeny pro všechny druhy nastavení systému a základní modely přenosového prostředí. Jsou zde popsány výsledky vlivu použití MIMO technologií na kvalitu příjmu řídicí informace především v únikových kanálech. Druhá část práce je zaměřena na možnost nasazení systému LTE ve sdíleném pásmu ISM (2.4 GHz). Jsou zde představeny základní koncepce použití, na jejichž základě je vytvořen scénář simulací. Kapitola dále popisuje tvorbu simulátoru koexistence LTE a systému Wi-Fi v přeneseném pásmu ISM 2.4GHz. Jsou zde uvedeny výsledky simulací koexistence LTE a rušivého systému Wi-Fi provedených dle vytvořeného scénáře. Výsledky simulací koexistence LTE a Wi-Fi jsou ověřeny měřením v laboratorních podmínkách. Toto porovnání je důležité z hlediska optimalizace simulátoru koexistence. Dle výsledků obou typů simulací a měření jsou stanovena provozní doporučení, která mají přispět k bezpečnému a spolehlivému vysílání a příjmu řídicích informací LTE i při nepříznivých podmínkách příjmu.The doctoral thesis is focused on a signal processing in the LTE physical control channels and performance analysis of control information transmission according to receiving conditions. The thesis is divided into two parts. The first part deals with simulation of the transmission of control information in baseband. The created simulators for uplink and downlink are presented. The simulations are performed for all possible system settings and various channel models. The MIMO influence on a quality of control information reception under fading channels is also presented. The second part of the thesis is focused on LTE utilization in shared channel ISM (2.4 GHz). The basic LTE application concept for ISM band is presented. This concept is fundamental to created simulation scenario. The chapter also presents the LTE and Wi-Fi coexistence simulator in 2.4 GHz ISM passband. The coexistence simulation are presented according to simulation scenario and the results are shown. The simulated coexistence analysis results are verified in laboratory environment. The comparison of the simulated and the measured coexistence analysis results is crucial for further optimization of the coexistence simulator. Recommendations for optimal and reliable operation of LTE are specified according to the simulated and the measured results. Recommendations should be useful to the reliable transmission of LTE control information in bad receiving conditions.

Computational Design of Stable and Soluble Biocatalysts

Natural enzymes are delicate biomolecules possessing only marginal thermodynamic stability. Poorly stable, misfolded, and aggregated proteins lead to huge economic losses in the biotechnology and biopharmaceutical industries. Consequently, there is a need to design optimized protein sequences that maximize stability, solubility, and activity over a wide range of temperatures and pH values in buffers of different composition and in the presence of organic cosolvents. This has created great interest in using computational methods to enhance biocatalysts' robustness and solubility. Suitable methods include (i) energy calculations, (ii) machine learning, (iii) phylogenetic analyses, and (iv) combinations of these approaches. We have witnessed impressive progress in the design of stable enzymes over the last two decades, but predictions of protein solubility and expressibility are scarce. Stabilizing mutations can be predicted accurately using available force fields, and the number of sequences available for phylogenetic analyses is growing. In addition, complex computational workflows are being implemented in intuitive web tools, enhancing the quality of protein stability predictions. Conversely, solubility predictors are limited by the lack of robust and balanced experimental data, an inadequate understanding of fundamental principles of protein aggregation, and a dearth of structural information on folding intermediates. Here we summarize recent progress in the development of computational tools for predicting protein stability and solubility, critically assess their strengths and weaknesses, and identify apparent gaps in data and knowledge. We also present perspectives on the computational design of stable and soluble biocatalysts

Signal processing in ZigBee system

Diplomová práce na téma Zpracování signálů v systému ZigBee je zaměřena na vlastnosti fyzické vrstvy systému ZigBee (standard IEEE 802.15.4 - 2003). Práce se skládá ze tří částí. První část obsahuje obecný náhled na použití a vlastnosti systému. Druhá část se zaměřuje na vrstvu řízení přístupu k fyzickému médiu a detailně pak na fyzickou vrstvu systému ZigBee. Zde je popsáno zpracování signálů v jednotlivých rádiových pásmech. V poslední části práce je detailně popsán vytvořený model systému v programovém prostředí MATLAB pro frekvenční pásmo 868/915 MHz resp. 2450 MHz. Poslední část práce se věnuje simulacím BER v závislosti na poměru C/N. Vyšetřena je rovněž koexistence se systémy pracujícími ve stejném nebo blízkém kmitočtovém pásmu. Na základě výsledků simulací jsou v práci uvedeny doporučení pro minimalizaci bitové chybovosti při používání systému ZigBee.Master's thesis The Signal Processing in ZigBee System is focused on properties of Physical Layer of ZigBee (standard IEEE 802.15.4 - 2003). The work consists of three parts. The first part contains common view on using and properties of ZigBee. The next part focuses on the Medium Access Control Layer and in detail on the Physical Layer. There described signal processing in the Physical Layer in individual radio bands. The last part of the project contains the process of modeling in the MATLAB for both models of system ZigBee (bands 868/915 MHz and 2450 MHz). The last part of thesis deals with the simulations of BER depending on Carrier-to-Noise Ratio. Also examined the coexistence of systems operating in the same or a nearby frequency band. Based on the results of simulations there are given recommendations for the use of the ZigBee system in minimizing BER.

Cryptographic methods of data security

Bakalářská práce na téma Kryptografické metody zabezpečení dat sestává ze tří částí. V první části jsou rozvedeny obecné teoretické principy, kterých se v této oblasti využívá. Dále jsou zde zmíněny soudobé i historické kryptografické standardy či algoritmy. Druhá část bakalářské práce poukazuje na možnosti prolomení těchto standardů, na dnes nejpoužívanější kryptoanalytické principy a jejich aplikaci v praxi, obzvláště v oblasti počítačových sítí a jejich služeb. Závěrečná část obsahuje popis vývoje jednoduché počítačové aplikace, která demonstruje použití kryptografických metod v zabezpečení souborů v osobním počítači.Bachelor‘s thesis on theme Cryptographic methods of data security consists of three parts. In first part are itemized general theoretical principles, which employs in these sphere. There are also mentioned not only contemporaneous but historical cryptographic standards or algorithms. The second part of these bachelor‘s thesis refer to a possibility of breaking these standards. There are described most applied cryptoanalytics principes and their practical using, especially in the sphere of computer networks and their services. The final part contains a description of the development of simple computer application, which demonstrates the use cryptographic methods in the security packages in personal computer.

Methods of Thermal Analysis as a Tool to Develop Cryopreservation Protocols of Vegetatively Propagated Crops

Cryopreservation is considered to be a reliable biotechnological tool for the long-term conservation of vegetatively propagated plant germplasm. The technique is based on freezing plant tissues at an ultralow temperature. However, high water content in plant tissue can result in injury during the cooling and thawing processes. Water behavior in the process of cryopreservation can be assessed by the use of thermal analysis method. This chapter demonstrates how the use of heat flux-type differential scanning calorimetry (DSC) thermal analysis methods such as standard DSC, temperature-modulated DSC (TMDSC), and quasi-isothermal temperature-modulated DSC (QITMDSC) can be used to assess the amount of freezable water and verify if the tissue being used has reached glass transition as well as analyzing the thermal events during cooling and freezing to reduce crystallization and damage by frost. Here, you can find a guide on how these thermal analysis methods can be applied, through concrete examples of each method and their use in the development of a more reliable and precise cryopreservation protocol for vegetatively propagated plant species

The negativity bias in news about how public money is used affects our willingness to pay taxes

To meet the public’s preference for negative content. the media tend to overreport negative news. Miloš Fišar, Tommaso Reggiani, Fabio Sabatini, and Jiří Špalek write that this negativity bias in the coverage of economic policy issues decreases tax compliance. Conversely, when people are exposed to authentic information about the appropriate use of tax revenues, compliance increases significantly

Cryoresistance of Antarctic endemic lichen Himantormia lugubris: Analysis of photosystem II functionality using a constant-rate cooling approach

It is well established that lichens from polar regions of the Earth are capable to perform photosynthesis at sub-zero temperatures. Majority of them show a high degree of cryoresistance, however, species-specific differences exist. Therefore, the aim of our study was to evaluate behaviour of primary photochemical processes of photosynthesis in Antarctic endemic species Himantormia lugubris at sub-zero temperature. For the purpose, the method of constant rate (2°C min-1) cooling (from +20 to -40°C) with simultaneous measurements of chlorophyll fluorescence parameters related to photosystem II (PSII) was used. During the cooling, potential yield of photosynthetic processes in PSII (FV/FM), and effective quantum yield of PSII (ΦPSII) were measured in 30 s interval. From the FV/FM and ΦPSII data sets, S-curves reflecting temperature dependence of the two chlorophyll fluorescence parameters were constructed and analyzed. The S-curves were found tri-phasic in response to sample temperature decline: (1) slight or no decline phase, (2) rapid decline phase, followed by (3) slow change reaching critical temperature at which the primary photosynthetic processes were fully inhibited. Critical temperature was found -30 and -20°C for FV/FM, and ΦPSII, respectively. The latter critical temperature was accompanied by an increase in background chlorophyll fluorescence (F0) indicating inhibition of energy transfer from light-harvesting complexes to core of PSII. A newly-designed chlorophyll fluorescence parameter (a differential, i.e. the difference between the maximum value-normalized FV/FM, and ΦPSII) was used in order to evaluate the temperature at which the processes related to photosynthetic electron flow through thylakoid membrane carriers (ΦPSII) and the energy flow through PSII (FV/FM) differed to a largest extent. This parameters proved to be temperature-dependent and useful in the evaluation of cryoresistance.  Based on our study, H. lugubris, its primary photosynthetic processes in particular, might be considered as higly resistant to sub-zero temperature

Mathematical modelling of a process-economic of protein hydrolyzate production from lupine flour

The aim of the present work is to perform the mathematical modelling and computer simulation of the lupine flour hydrolysis technology, which includes the calculations and also the partial comparison of different process variants. Lupine flour is deemed as a source of valuable protein with a substantial content of essential amino acids which has a significant impact on the prevention of various diseases in a human diet. The proposed mathematical model for the production process enables to accomplish the optimal operating conditions while the specific costs for the production of valuable hydrolyzate are minimal. The suggested process-economic mathematical model for the production hydrolysis unit comprises the three main processes for the implementation of the hydrolyzate production, i.e. the chemical reaction and its kinetics, the separation of solids from the reaction mixture by filtration and the thickening of the final product. The results have shown that in most of the simulation cases, the economic optimum occurs and thus the application of the model is valuable for the practical purposes of protein hydrolyzate production. © 2019, World Scientific and Engineering Academy and Society. All rights reserved