Fast RF-CV characterization through high-speed 1-port S-parameter measurements

We present a novel method to measure the capacitance-voltage relation of an electronic device. The approach is accurate, very fast, and cost-effective compared to the existing off-the-shelf solutions. Capacitances are determined using a single-frequency 1-port S-parameter setup constructed from discrete components. We introduce a new way to correct for non-linearities of the used components, which greatly increases the accuracy with which the phase and magnitude of the reflected signal is measured. The measurement technique is validated on an RF-MEMS capacitive switch and a BST tunable capacitor. Complete capacitance-voltage curves are measured in less than a millisecond, with a measurement accuracy well below 1%.\ud \u

Evolutionary Synthesis of Analog Electronic Circuits Using EDA Algorithms

Disertační práce je zaměřena na návrh analogových elektronických obvodů pomocí algoritmů s pravěpodobnostními modely (algoritmy EDA). Prezentované metody jsou na základě požadovaných charakteristik cílových obvodů schopny navrhnout jak parametry použitých komponent tak také jejich topologii zapojení. Tři různé metody využití EDA algoritmů jsou navrženy a otestovány na příkladech skutečných problémů z oblasti analogových elektronických obvodů. První metoda je určena pro návrh pasivních analogových obvodů a využívá algoritmus UMDA pro návrh jak topologie zapojení tak také hodnot parametrů použitých komponent. Metoda je použita pro návrh admitanční sítě s požadovanou vstupní impedancí pro účely chaotického oscilátoru. Druhá metoda je také určena pro návrh pasivních analogových obvodů a využívá hybridní přístup - UMDA pro návrh topologie a metodu lokální optimalizace pro návrh parametrů komponent. Třetí metoda umožňuje návrh analogových obvodů obsahujících také tranzistory. Metoda využívá hybridní přístup - EDA algoritmus pro syntézu topologie a metoda lokální optimalizace pro určení parametrů použitých komponent. Informace o topologii je v jednotlivých jedincích populace vyjádřena pomocí grafů a hypergrafů.Dissertation thesis is focused on design of analog electronic circuits using Estimation of Distribution Algorithms (EDA). Based on the desired characteristics of the target circuits the proposed methods are able to design the parameters of the used components and theirs topology of connection as well. Three different methods employing EDA algorithms are proposed and verified on examples of real problems from the area of analog circuits design. The first method is capable to design passive analog circuits. The method employs UMDA algorithm which is used for determination of the parameters of the used components and synthesis of the topology of their connection as well. The method is verified on the problem of design of admittance network with desired input impedance function which is used as a part of chaotic oscillator circuit. The second method is also capable to design passive analog circuits. The method employs hybrid approach - UMDA for synthesis of the topology and local optimization method for determination of the parameters of the components. The third method is capable to design analog circuits which include also ac- tive components such as transistors. Hybrid approach is used. The topology is synthesized using EDA algorithm and the parameters are determined using a local optimization method. In the individuals of the population information about the topology is represented using graphs and hypergraphs.

Material Planning for Remanufacturing Defense Assets

This paper develops a planning system for depots remanufacturing components of defense assets, such as helicopters, armored cars, and so forth. These depots take in used assets, disassemble them, repair, upgrade and reassemble them to supply US troops and, occasionally, foreign military services of allied nations. Uncertainty in the supply of used components, the yield of good parts, and the demand for remanufactured products makes this a difficult process to manage. This article describes a multi-period material planning system for the process. It covers everything from collection to final delivery. The system is based on material requirements planning, a method familiar to many managers. It uses linear programming to develop purchase recommendations and to schedule the disassembly of the used components. The researcher held meetings with remanufacturing practitioners to set the system parameters and to evaluate the approach

Earth Pressure on Retaining Walls and Buried Pipe

This paper describes the results of earth pressure measurements buried pipes. Conventional earth pressure gauges fixed on the walls were type earth pressure gauges which covers the whole wall surface were used components of the resultant earth pressures were measured

Development of New Crispy Breads with the Inclusion of Vegetable Additives and Evaluation of Their Quality

Spelt-based crispy breads with the inclusion of herbal supplements (powders of milk thistle, mountain ash, wild rose and green tea extract) and the results of assessing the quality of new products by organoleptic and physico-chemical indicators are presented. For a tasting evaluation, a point scale has been developed for the organoleptic evaluation of sugary-grain crispy breads. On the basis of which the organoleptic analysis of crispy breads, enriched with herbal supplements, has been carried out It is established that the introduction of vegetable additives in the composition of crispy bread leads to an improvement in the organoleptic characteristics of finished products. These products are characterized by a crispy, porous structure, an attractive light cream color, a harmonious taste, a pronounced smell of used additives. According to the results of the tasting evaluation, samples enriched with herbal supplements received the highest score in relation to the control sample, which meets the requirements of potential consumers. On the basis of physico-chemical indicators, it has been established that the introduction of grain additives to crispy breads does not impair the physic-chemical properties of these products.On the basis of the obtained data, the expediency of the production of new spelt-based crispy breads with the inclusion of enriching additives with improved organoleptic properties is substantiated