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Fully-differential fractional frequency filters
Zapletal, Miroslav ; Dvořák, Jan (referee) ; Langhammer, Lukáš (advisor)
This diploma thesis is concentrated to fully differential and non-differential fractional-order filters with active elements. It describes how we can obtain fractional-order fully-differential filters design from non-differential design, thesis describes realization in OrCad program and simulation of this project. The first part of the thesis concerns theoretical analysis of frequency filters, active elements and fractional-order filters. The second part of the thesis includes designs of filters and simulations of differential structures and rest of non-differential structures simulation. The following part of the thesis concerns practical realization and experimental measurment of differential fractional-order filter. In the last part of this project, thesis evaluates all results which were revealed in our simulations and experimental measurment.
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Hydromorphological survey of the Bilina River
Kyselka, Jan ; Matoušková, Milada (advisor) ; Langhammer, Jakub (referee)
The main aim of this thesis is assessment and presentation of results of the hydromorphological survey of the Bílina river, which belongs to rivers with the biggest anthropogenic impact in the Czech Republic. The method Hydroecological monitoring (HEM, Langhammer, 2007) was used for the survey. This method is compatible with the Water Framework Directive 2000/60/EC. 53 parts of the river with the lenght 31,99 km were assessed. The thesis also includes assessement of the rainoff regime and information about protection of water ecosystems and sources in the Bílina river basin. Keywords: hydromorphology, HEM, Bílina river
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Modelling the course of extreme floods in the context of landscape changes and integrated flood protection
Jeníček, Michal ; Langhammer, Jakub (advisor) ; Zezulák, Jiří (referee) ; Szolgay, Ján (referee)
Introduction Floods mean a considerable hazard for mankind. Effective protection against their impact represents one of the basic hydrology and water management tasks. The conception of flood protection came tfuough development reflecting the progress in natural processes description, flood experiences and also improvement in technology possibilities enabling better computation of flood measures effectiveness. Cunently centralized flood protection concept is replaced with íntegrated flood protection concept (Langhammer et al., 2008b; Dumbrovský et al., 2006)' which gives the complex flood protection solution for the whole basin by means of smaller, close{o-natural measures, such as small retention reservoirs. land use change, suitable agrotechnical principles etc. The thesis can be divided into three main parts that form three main pillars ofintegrated flood protection. These pillars are represented by three case studies. First study was made in Blanice River basin. It computes flood extreme changes in condition of changing landscape. Results could lead to positive land cover change which could cause the flood peak decrease. Second study was made in Chomutovka River catchment (Ore Mts.). It quantifies dry retention reservoirs impact on the course of floods by different precipitation extremities. Third study...
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Fully-Differential Frequency Filters with Modern Active Elements
Langhammer, Lukáš ; Dostál, Tomáš (referee) ; Štork, Milan (referee) ; Jeřábek, Jan (advisor)
Tato disertační práce se zaměřuje na výzkum v oblasti frekvenčních filtrů. Hlavním cílem je navrhnout a analyzovat plně diferenční kmitočtové filtry pracující v proudovém módu a využívající moderní aktivní prvky. Prezentované filtry jsou navrženy za použití proudových sledovačů, operačních transkonduktančních zesilovačů, plně diferenčních proudových zesilovačů a transrezistančních zesilovačů. Návrh se zaměřuje na možnost řídit některý z typických parametrů filtru pomocí řiditelných aktivních prvků, které jsou vhodně umístněny do obvodové struktury. Jednotlivé prezentované filtry jsou navrženy v nediferenční a diferenční verzi. Velký důraz je věnován srovnání plně diferenčních struktur s jejich odpovídajícími nediferenčními formami. Funkčnost jednotlivých návrhů je ověřena simulacemi a v některých případech i experimentálním měřením.
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Proposal of the fractal order filtering structures
Uher, Jiří ; Dvořák, Jan (referee) ; Langhammer, Lukáš (advisor)
This thesis deals with the fractional (1+)-order filters. The proposed filters operate in the current-mode. The derivation of the filters has been achieved using a third-order aproximation of the coresponding fractional-order transfer functions. It also describes active elements such as universal current conveyor, current follower and operational transconductance amplifier. In the end of this thesis some new circuit solutions of the fractional-order filter are proposed. Then the proposed filters are realized and experimentally measured.
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Fractional-order filter structures
Lefler, Filip ; Langhammer, Lukáš (referee) ; Dvořák, Jan (advisor)
Semestral thesis deals with fractional-order frequency filters. There is descripe proposal of the filter, their simulations and practical realizations. The first part is focused at the introduction to a frequency filters. The following is chapter which explore various proposals fractional-order frequency filters. The next chapter describes used activ elements in this thesis. Then there is briefly described a method of the signal flow graphs. The following is a description of the theoretical design of lowpass and highpass frequency filter, where order of the filter is between the first and second. Another part deal with the design and simulation of the four circuits. There are two curcuits consists of transconductance amplifiers (BOTA) and two curcuist consists of current followers. The last part of the thesis deals with practical realization of the two fractional-order filters.
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Electronically reconfigurable frequency filters
Gajdoš, Adam ; Langhammer, Lukáš (referee) ; Jeřábek, Jan (advisor)
The aim of the thesis was design of reconnection-less and electronically reconfigurable filters of SISO type with non-traditional active elements. Adjustability of bandwidth or quality factor is also required. First part of the thesis deals with theoretical analysis of filters, their operation modes and design of frequency filters using Signal-flow graph method aswell. Last but not least, electronical reconfiguration of transfer function and parasitic analysis was discussed. Another part describes active elements used in the practical part of thesis. Behaviors and design of active elements using existing circuits (e.g. UCC,EL2082) are described and their transformation into the Signal-flow graph form too. In the practical part five reconnection-less and reconfigurable filters of SISO type was designed using SNAP program. Simulations were done using Orcad program with ideal and real simulation models of active elements. Last part deals with filter design in EAGLE and experimental measurement.
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Fully-differential frequency filter designing with current active elements using signal-flow graphs method
Štork, Petr ; Jeřábek, Jan (referee) ; Langhammer, Lukáš (advisor)
This master’s thesis deals with designing of fully-differential current-mode frequency filters using signal-flow graphs method. The first part is focused on a general description of frequency filters, its function and division. Active elements that create these frequency filters, such as multi-output current follower (MO-CF), balanced or multi-output transconductance amplifier (BOTA, MOTA) and digitally adjustace current amplifier (DACA) are described in the following part. Next, problems and various techniques of designing such filters are discussed on a theoretic basis. In the remaining part of the thesis there are six circuits of frequency filters described in detail; these connections are then transferred of passive elements to a proposed connections, with the assistance of a so-called reflection. Calculations of passive form are stated, as well as results of simulations, where nondifferential and differential variations of these designed frequency filters are compared. Finaly, it has been selected some variants of designs, which has been manufactured, then measured out and resulet has been compare between each other.
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Universal precision rectifiers with current active elements
Ryšavý, Lukáš ; Jeřábek, Jan (referee) ; Langhammer, Lukáš (advisor)
In this thesis new circuit solutions of universal precision rectifiers with current active elements are proposed. Based on the knowledge of current active elements, universal precision rectifiers and adverse impacts on these circuits new circuit solutions are proposed. These circuits are then simulated and compared with the known circuits of precision rectifiers. In concusion two original circuits and two proposed circuit solutions based on original ones are implemented, their properties are experimentally measured and their function are verified. The main active element in the original circuit are the OPA or THS, the proposed circuits are used the OPA and THS and the universal current conveyor, which offers a wide range of application use and realization of different variations of active current elements.
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