Wireless sensor for intelligent buildings

Bakalářská práce se zabývá porovnáním energetické náročnosti dvou měřících schémat měřicí teplotu pro bezdrátové měření v budově. Měření probíhá pomocí bezdrátových modulů ZigBit900 založených na standardu ZigBee. V prvním celku se práce věnuje teoretickému popisu komunikačního standardu. Rozebírá základní problematiku technologie a uvádí tak čtenáře do problematiky. Druhá část popisuje vývojový kit ZigBit 900. Další část uvádí do základní problematiky programovacího balíčku BitCloud, který je určen pro programování tohoto vývojového kitu. Dále je návrh dvou měřících schémat teploty, výběr vhodné aplikace, části změněného kódu a popis měření teploty. v Poslední kapitole jsou zobrazena a vyhodnocena naměřená teplota, vypočítána teoretická hodnota spotřeby pro kmitočtové pásmo 868 MHz a 2,4 GHz. V závěru je diskuze dosažených výsledků.The theme of the Bachelor’s work is based on the comparison of two measuring schemes measured the temperature for the wireless measurement of the temperature in the building and the comparison of the power consumption of these schemes. Measurement is perforemed by using wireless modules ZigBit900 which are based on ZigBee standard. The first part of the work deals with the theoretical description of the communication standard. There is analyzed the basic issue of technology and the reader can be indicated to the issue. In the second part there is mentioned the description of the developmental kit ZigBit 900. Another section brings the basic information about the programming package BitCloud, which is used for programming of the developmental kit. In addition, designs of two measuring schemes of temperature are mentioned there. Then the reader find there the selection of appropriate application and the part of emended code and the description of temperature measurement. The last chapter schows the measuring and assessing of the temperature. The calculation of the theoretical value of power comsumption for the frequncy band 868 MHz and 2,4 GHz is the lastest researched problem in the work. In conclusion of this Bachelor’s work is included the discussion of achieved results.

Optimalizace řezných parametrů při obrábění niklové slitiny Haynes 718 plynovým laser CO2

This article deals with the application of laser technology and the optimization of parameters in the area of nickel alloy laser cutting intended for application in the aircraft industry. The main goal is to outline possibilities of use of the laser technology, primarily its application in the area of 3D material cutting. This experiment is focused on the optimization of cutting parameters of the Haynes 718 alloy with a gas CO2 laser. Originating cuts are evaluated primarily from the point of view of cut quality and accompanying undesirable phenomena occurring in the process of cutting. In conclusion the results achieved in the metallographic laboratory are described and analyzed.Článek se zabývá aplikací laserové technologie a optimalizací parametrů v oblasti laserového řezání niklové slitiny určené pro aplikaci v leteckém průmyslu. Hlavním cílem je nastínit možnosti využití laserové technologie, především pak její aplikaci v oblasti 3D řezání materiálů. Konkrétně je experiment zaměřen na optimalizaci parametrů řezání slitiny Haynes 718 na plynovém CO2 laseru. Na hodnocení vzniklých řezů je nahlíženo především z hlediska kvality řezu a doprovodných nežádoucích jevů vznikajících při procesu řezání. Závěrem jsou popsány a zhodnoceny výsledky dosažené v metalografické laboratoři

Multimedia as a modernization direction in the course of teaching "History of Ukraine"

Використання мультимедійних презентацій в системі сучасної освіти займає все більше місце та стає певною повсякденністю. Мультимедія під час викладання дисципліни "Історія України" є важливим елементом освітнього процесу, яка покликана мотивувати студентів до навчання, поліпшити сприйняття інформації, зробити навчальний процес сучасним, цікавим та продуктивним. Мультимедійні презентації створені викладачами та студентами постійно вдосконалюються та являються модернізаційним напрямком навчання та комунікації.The use of multimedia presentations in the system of modern education takes up an increasing number of places and becomes a "daily routine". Multimedia during the teaching of the discipline "History of Ukraine" is an important element of the educational process. During lectures and seminars, using the multimedia technologies is a topical issue today. Multimedia is designed to motivate students to study, improve perceptions of information, make the learning process interesting and productive. Multimedia presentations created by lecturers and students serve as a kind of communication. They are constantly improving and being a modernization training area

Laser Cutting of Materials of Various Thicknesses

Thise paper deals with the application of laser technology and optimizing the parameters for cutting nickel alloy. The theoretical part of the paper describes various types of lasers, their principles and usage. The experimental part focuses on optimizing the section parameteres of Haynes 718 alloy using a CO2 gas laser. This alloy is employed in the production of components for the aircraft industry. The experiment was performed on the Wibro Delta laser system designed for sizable parts. The actual section is measured with respect to its quality and any accompanying side effects that occur during the process. In this case, laser output and cutting speed were the parameters with most influence on the final cut. The summary explains the results achieved in a metallographic laboratory

Approximation of Parametric Derivatives by the Empirical Interpolation Method

We introduce a general a priori convergence result for the approximation of parametric derivatives of parametrized functions. We consider the best approximations to parametric derivatives in a sequence of approximation spaces generated by a general approximation scheme, and we show that these approximations are convergent provided that the best approximation to the function itself is convergent. We also provide estimates for the convergence rates. We present numerical results with spaces generated by a particular approximation scheme—the Empirical Interpolation Method—to confirm the validity of the general theory

Technical Development of a New Semispherical Radiofrequency Bipolar Device (RONJA): Ex Vivo and In Vivo Studies

The aim of this study is to inform about the development of a new semispherical surgical instrument for the bipolar multielectrode radiofrequency liver ablation. Present tools are universal; however they have several disadvantages such as ablation of healthy tissue, numerous needle punctures, and, therefore, longer operating procedure. Our newly designed and tested semispherical surgical tool can solve some of these disadvantages. By conducting an in vivo study on a set of 12 pigs, randomly divided into two groups, we have compared efficiency of the newly developed instrument with the commonly used device. Statistical analysis showed that there were no significant differences between the groups. On average, the tested instrument RONJA had shorter ablation time in both liver lobes and reduced the total operating time. The depth of the thermal alteration was on average 4 mm larger using the newly tested instrument. The new radiofrequency method described in this study could be used in open liver surgery for the treatment of small liver malignancies (up to 2 cm) in a single application with the aim of saving healthy liver parenchyma. Further experimental studies are needed to confirm these results before clinical application of the method in the treatment of human liver malignancies

The GNAT method for nonlinear model reduction: effective implementation and application to computational fluid dynamics and turbulent flows

The Gauss--Newton with approximated tensors (GNAT) method is a nonlinear model reduction method that operates on fully discretized computational models. It achieves dimension reduction by a Petrov--Galerkin projection associated with residual minimization; it delivers computational efficency by a hyper-reduction procedure based on the `gappy POD' technique. Originally presented in Ref. [1], where it was applied to implicit nonlinear structural-dynamics models, this method is further developed here and applied to the solution of a benchmark turbulent viscous flow problem. To begin, this paper develops global state-space error bounds that justify the method's design and highlight its advantages in terms of minimizing components of these error bounds. Next, the paper introduces a `sample mesh' concept that enables a distributed, computationally efficient implementation of the GNAT method in finite-volume-based computational-fluid-dynamics (CFD) codes. The suitability of GNAT for parameterized problems is highlighted with the solution of an academic problem featuring moving discontinuities. Finally, the capability of this method to reduce by orders of magnitude the core-hours required for large-scale CFD computations, while preserving accuracy, is demonstrated with the simulation of turbulent flow over the Ahmed body. For an instance of this benchmark problem with over 17 million degrees of freedom, GNAT outperforms several other nonlinear model-reduction methods, reduces the required computational resources by more than two orders of magnitude, and delivers a solution that differs by less than 1% from its high-dimensional counterpart

A Certified Trust Region Reduced Basis Approach to PDE-Constrained Optimization

Parameter optimization problems constrained by partial differential equations (PDEs) appear in many science and engineering applications. Solving these optimization problems may require a prohibitively large number of computationally expensive PDE solves, especially if the dimension of the design space is large. It is therefore advantageous to replace expensive high-dimensional PDE solvers (e.g., finite element) with lower-dimensional surrogate models. In this paper, the reduced basis (RB) model reduction method is used in conjunction with a trust region optimization framework to accelerate PDE-constrained parameter optimization. Novel a posteriori error bounds on the RB cost and cost gradient for quadratic cost functionals (e.g., least squares) are presented and used to guarantee convergence to the optimum of the high-fidelity model. The proposed certified RB trust region approach uses high-fidelity solves to update the RB model only if the approximation is no longer sufficiently accurate, reducing the number of full-fidelity solves required. We consider problems governed by elliptic and parabolic PDEs and present numerical results for a thermal fin model problem in which we are able to reduce the number of full solves necessary for the optimization by up to 86%. Key words: model reduction, optimization, trust region methods, partial differential equations, reduced basis methods, error bounds, parametrized systemsFulbright U.S. Student ProgramNational Science Foundation (U.S.). Graduate Research Fellowship ProgramHertz FoundationUnited States. Department of Energy. Office of Advanced Scientific Computing Research (Award DEFG02-08ER2585)United States. Department of Energy. Office of Advanced Scientific Computing Research (Award DE-SC0009297

A weighted reduced basis method for parabolic PDEs with random data

This work considers a weighted POD-greedy method to estimate statistical outputs parabolic PDE problems with parametrized random data. The key idea of weighted reduced basis methods is to weight the parameter-dependent error estimate according to a probability measure in the set-up of the reduced space. The error of stochastic finite element solutions is usually measured in a root mean square sense regarding their dependence on the stochastic input parameters. An orthogonal projection of a snapshot set onto a corresponding POD basis defines an optimum reduced approximation in terms of a Monte Carlo discretization of the root mean square error. The errors of a weighted POD-greedy Galerkin solution are compared against an orthogonal projection of the underlying snapshots onto a POD basis for a numerical example involving thermal conduction. In particular, it is assessed whether a weighted POD-greedy solutions is able to come significantly closer to the optimum than a non-weighted equivalent. Additionally, the performance of a weighted POD-greedy Galerkin solution is considered with respect to the mean absolute error of an adjoint-corrected functional of the reduced solution.Comment: 15 pages, 4 figure