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31.
A new class of reduced‐order controllers is obtained for the H∞ problem. The reduced‐order controller does not compromise the performance attained by the full‐order controller. Algorithms for deriving reduced‐order H∞ controllers are presented in both continuous and discrete time. The reduction in order is related to unstable transmission zeros of the subsystem from disturbance inputs to measurement outputs. In the case where the subsystem has no infinite zeros, the resulting order of the H∞ controller is lower than that of the existing reduced‐order H∞ controller designs which are based on reduced‐order observer design. Furthermore, the mechanism of the controller order reduction is analysed on the basis of the two‐Riccati equation approach. The structure of the reduced‐order H∞ controller is investigated. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
32.
Liliana Marinescu Denisa Ficai Anton Ficai Ovidiu Oprea Adrian Ionut Nicoara Bogdan Stefan Vasile Laura Boanta Alexandru Marin Ecaterina Andronescu Alina-Maria Holban 《International journal of molecular sciences》2022,23(11)
The synthesis of nanoparticles from noble metals has received high attention from researchers due to their unique properties and their wide range of applications. Silver nanoparticles (AgNPs), in particular, show a remarkable inhibitory effect against microorganisms and viruses. Various methods have been developed to obtain AgNPs, however the stability of such nanostructures over time is still challenging. Researchers attempt to obtain particular shapes and sizes in order to tailor AgNPs properties for specific areas, such as biochemistry, biology, agriculture, electronics, medicine, and industry. The aim of this study was to design AgNPs with improved antimicrobial characteristics and stability. Two different wet chemical routes were considered: synthesis being performed (i) reduction method at room temperatures and (ii) solvothermal method at high temperature. Here, we show that the antimicrobial properties of the obtained AgNPs, are influenced by their synthesis route, which impact on the size and shape of the structures. This work analyses and compares the antimicrobial properties of the obtained AgNPs, based on their structure, sizes and morphologies which are influenced, in turn, not only by the type or quantities of precursors used but also by the temperature of the reaction. Generally, AgNPs obtained by solvothermal, at raised temperature, registered better antimicrobial activity as compared to NPs obtained by reduction method at room temperature. 相似文献
33.
Alexander Kostyunin Tatiana Glushkova Alexander Stasev Rinat Mukhamadiyarov Elena Velikanova Leo Bogdanov Anna Sinitskaya Maxim Asanov Evgeny Ovcharenko Leonid Barbarash Anton Kutikhin 《International journal of molecular sciences》2022,23(12)
A 72-year-old female patient with mixed rheumatic mitral valve disease and persistent atrial fibrillation underwent mitral valve replacement and suffered from a combined thrombosis of the bioprosthetic valve and the left atrium as soon as 2 days post operation. The patient immediately underwent repeated valve replacement and left atrial thrombectomy. Yet, four days later the patient died due to the recurrent prosthetic valve and left atrial thrombosis which both resulted in an extremely low cardiac output. In this patient’s case, the thrombosis was notable for the resistance to anticoagulant therapy as well as for aggressive neutrophil infiltration and release of neutrophil extracellular traps (NETs) within the clot, as demonstrated by immunostaining. The reasons behind these phenomena remained unclear, as no signs of sepsis or contamination of the BHV were documented, although the patient was diagnosed with inherited thrombophilia that could impede the fibrinolysis. The described case highlights the hazard of immunothrombosis upon valve replacement and elucidates its mechanisms in this surgical setting. 相似文献
34.
Jingjin Dong Jian Liu Xinkai Qiu Ryan Chiechi L.Jan Anton Koster Giuseppe Portale 《工程(英文)》2021,7(5):647-654
Engineering the electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)holds great potential for various applications such a... 相似文献
35.
Jeremy Rott Eva Teresa Toepfer Maria Bartosova Ana Kolevica Alexander Heuser Michael Rabe Geert Behets Patrick C. DHaese Viktoria Eichwald Manfred Jugold Ivan Damgov Sotirios G. Zarogiannis Rukshana Shroff Anton Eisenhauer Claus Peter Schmitt 《International journal of molecular sciences》2022,23(14)
Serum calcium isotopes (δ44/42Ca) have been suggested as a non-invasive and sensitive Ca balance marker. Quantitative δ44/42Ca changes associated with Ca flux across body compartment barriers relative to the dietary Ca and the correlation of δ44/42CaSerum with bone histology are unknown. We analyzed Ca and δ44/42Ca by mass-spectrometry in rats after two weeks of standard-Ca-diet (0.5%) and after four subsequent weeks of standard- and of low-Ca-diet (0.25%). In animals on a low-Ca-diet net Ca gain was 61 ± 3% and femur Ca content 68 ± 41% of standard-Ca-diet, bone mineralized area per section area was 68 ± 15% compared to standard-Ca-diet. δ44/42Ca was similar in the diets, and decreased in feces and urine and increased in serum in animals on low-Ca-diet. δ44/42CaBone was higher in animals on low-Ca-diet, lower in the diaphysis than the metaphysis and epiphysis, and unaffected by gender. Independent of diet, δ44/42CaBone was similar in the femora and ribs. At the time of sacrifice, δ44/42CaSerum inversely correlated with intestinal Ca uptake and histological bone mineralization markers, but not with Ca content and bone mineral density by µCT. In conclusion, δ44/42CaBone was bone site specific, but mechanical stress and gender independent. Low-Ca-diet induced marked changes in feces, serum and urine δ44/42Ca in growing rats. δ44/42CaSerum inversely correlated with markers of bone mineralization. 相似文献
36.
Jay Sagin Anton Sizo Howard Wheater Timothy D. Jardine 《International journal of remote sensing》2013,34(3):764-781
Tracking surface water coverage changes is a complicated task for many regions of the world. It is, however, essential to monitor the associated biological changes and bioproductivity. We present a methodology to track contemporary water coverage changes using optical remote sensing and use it to estimate historical summer water coverage in a large river delta. We used a geographical information system automated routine, based on the modified normalized difference water index, to extract the surface water coverage area (SWCA) from optical satellite data sets using the surface water extraction coverage area tool (SWECAT). It was applied to measure SWCA during drought and flood peaks in the Saskatchewan River Delta in Canada, from Landsat, SPOT and RapidEye images. Landsat results compared favourably with Canadian National Hydro Network (CNHN) GeoBase data, with deviations between SWCA classifications and the base CNHN GeoBase shapefile of ~2%. Difference levels between the extracted SWCA layer from Landsat and the higher resolution commercial satellites (SPOT and RapidEye) were also less than 2%. SWCA was tightly linked to discharge and level measurements from in-channel gauges (r2 > 0.70). Using the SWCA versus discharge relationship for the gauge with the longest record, we show that peak summer SWCA has declined by half over the last century, from 13% of our study area to 6%, with likely implications for fish and wildlife production. 相似文献
37.
Tomáš Brázdil Javier Esparza Stefan Kiefer Antonín Kučera 《Formal Methods in System Design》2013,43(2):124-163
The paper gives a summary of the existing results about algorithmic analysis of probabilistic pushdown automata and their subclasses. 相似文献
38.
Anton Chuvakin 《EDPACS》2013,47(4):8-12
Abstract. This article covers the importance of employing a cross-platform and cross-application log management approach rather than a siloed approach to collecting and reviewing logs for simplifying security and operational monitoring as well as compliance initiatives. 相似文献
39.
Nguyen Dang Manh Anton Evgrafov Allan Roulund Gersborg Jens Gravesen 《Computer Methods in Applied Mechanics and Engineering》2011,200(13-16):1343-1353
We consider a model problem of isogeometric shape optimization of vibrating membranes whose shapes are allowed to vary freely. The main obstacle we face is the need for robust and inexpensive extension of a B-spline parametrization from the boundary of a domain onto its interior, a task which has to be performed in every optimization iteration. We experiment with two numerical methods (one is based on the idea of constructing a quasi-conformal mapping, whereas the other is based on a spring-based mesh model) for carrying out this task, which turn out to work sufficiently well in the present situation. We perform a number of numerical experiments with our isogeometric shape optimization algorithm and present smooth, optimized membrane shapes. Our conclusion is that isogeometric analysis fits well with shape optimization. 相似文献
40.
In this paper, we study the response to external disturbances of a double integrator with a saturating feedback. For a class of disturbances that have bounded integrals over all intervals, we show that a linear static feedback law can always be designed to ensure boundedness of the states. Moreover, boundedness can be preserved if the disturbance is biased by a small DC signal. In the special case that the disturbance is made up of a finite number of sinusoids and a small bias, any linear static feedback ensures boundedness of the states. These results are an extension of previous results by Wen, Roy, and Saberi (2008). 相似文献