Economic loss in Czech photovoltaic power plants

This text provides a financial survey of a small sample of Czech photovoltaic (PV) plants. To evaluate the extent of market losses, we calculate the shadow market price of solar electricity. From the profit and loss accounts of the PV plants and the shadow market price we estimate the total economic loss generated by PV electricity sector in the Czech Republic. The presented microeconomic approach has two main advantages: Firstly, we work with real observed data, which offsets the drawback of a limited sample. Secondly, the profit accounting calculation enables sensitivity analysis with respect to key variables of the plants. We show that every million invested in PV plants would generate an annual loss of 11%. Given the estimated solar assets of CZK 127.4 billion (EUR 560 million) as of December 2010, this translates in at least CZK 14 billion lost in the Czech solar sector in 2011. About 42% of this loss is due to high technology costs and corresponds to pure dead weight loss, while the remaining 58% constitute the redistributive profit component of subsidies. Finally, we calculate that unless electricity prices increase or technology costs decrease approximately tenfold, PV plants will remain loss making

Traction Drive with PMSM: Frequency Characteristics Measurement

This paper describes a new method formeasurement of frequency characteristics of ac tractiondrives. It helps to find dangerous resonant frequencies ofthe traction drive supplied from a dc electrification systemand it allows finding danger oscillations of the dc-link LCfilter. The presented method has verified a drive with asurface mounted PMSM controlled by DTC. The resultsprove that the drive amplifies LC filter oscillations underconstant taken power. We have proposed an improvementof the drive control in order to protect the drive against thisphenomenon. The behaviour of the improved DTC has beenanalyzed by experiments made on the laboratory model ofthe traction drive of the rated power of 10 kW

Data mining for important amino acid residues in multiple sequence alignments and protein structures

Enzymes are highly efficient bio-catalysts interesting for industries and medicine. Therefore, a goal of utmost importance in biochemical research is to understand how an enzyme catalyzes a chemical reaction. Here, the computational identification of functionally or structurally important residue positions can be of tremendous help. The datasets that are most informative for the algorithms are the 3D structure of a protein and a multiple sequence alignment (MSA) composed of homologous sequences. For example, an MSA allows for the quantification of residue conservation. Residue conservation at a given position indicates that only one type of amino acid fulfills all constraints imposed by protein structure or function. Furthermore, a detailed analysis of less strictly conserved residue positions may identify pairs, whose orchestration is mutually dependent and induces correlated mutations. Both of these conservation signals are indicative of functionally or structurally important positions. In the first part of this thesis, methods of machine learning were used to identify and classify these residue positions. It was the aim to predict in a mutually exclusively manner a role in catalysis, ligand-binding or protein stability for each residue position of a protein. Unfortunately, for many proteins the 3D structure is unknown. For other proteins, the number of known homologs is not sufficient to compile a meaningful MSA. Therefore, three variants of a classifier were designed and implemented, named CLIPS-1D, CLIPS-3D, and CLIPS-4D. These multi-class support vector machines allow for a classification based on an MSA (CLIPS-1D), a 3D structure (CLIPS-3D), and a combination of both (CLIPS-4D). CLIPS-1D exploits seven sequence-based features, whereas CLIPS-3D utilizes seven structure-based features. CLIPS-4D combines the seven sequence-based features of CLIPS-1D with those two structure-based features that increased its classification performance. A comparison with existing methods and a detailed analysis on a well-studied enzyme confirmed state-of-the-art prediction quality for CLIPS-1D and CLIPS-4D. In the second part of this thesis an algorithm for the identification of correlated mutations was improved. A common method for the identification of correlated mutations is to deduce the mutual information (MI) of a pair of residue positions from an MSA. The classical MI is based on Shannon’s information theory that utilizes probabilities only. Consequently, these approaches do not consider the similarity of residue pairs, which is a severe limitation. In order to improve these algorithms, H2rs was developed for this thesis. Thus, the MIvalues originate from the von Neumann entropy (vNE), which takes into account amino acid similarities modeled by means of a substitution matrix. To further improve the specificity of H2rs, the significance of MIvNE-values was assessed with a bootstrapping approach. The analysis of a large in silico testbed and the detailed assessment of five well-studied enzymes demonstrated state-of-the-art performance

IZVJEŠTAVANJE O SPOLU I RASI/ETNICITETU U RANDOMIZIRANIM KONTROLIRANIM POKUSIMA OBJAVLJENIM U NAJBOLJIM ČASOPISIMA IZ PODRUČJA ANESTEZIOLOGIJE

Aim: The aim of this study was to assess reporting of data on sex and race/ethnicity in randomized controlled trials (RCTs) of interventions published in the highest-ranking journals from the field of anesthesiology. Methods: We analyzed RCTs published from 2014 to mid-2017 in the seven journals belonging to the top 25% in the field of Anesthesiology according to the 2016 Journal Impact Factor published by the database Journal Citation Reports. We extracted data regarding terminology for sex/gender, proportion of participants according to the race/gender and race/ethnicity, and results shown for the race/gender and race/ethnicity. Results: Among the analyzed 657 trials, none stratified participants based on sex/gender or race/ethnicity. Proportion of included women and men was very similar. Most of the included participants were white/Caucasian. Less than 10% of analyzed trial reported information about participants’ ethnicity. Sex-related results were reported in 7.9% and race/ethnicity-related results were reported in 0.15% of analyzed trials. Of the 52 trials that reported sex-related results, 20 (38%) described that there was a significant difference between women and men in at least one analyzed outcome; among 8 trials that reported results based on race/ethnicity, 1 (12.5%) trial reported significant difference in at least one analyzed outcome for participants of different race/ethnicity. Less than 5% of analyzed trials addressed sex/gender or race/ethnicity in Discussion. Conclusion: Sex-specific and race/ethnicity aspects are neglected in anesthesiology trials, even though on average these trials included similar number of women and men. Outcomes related to anesthesiology and pain may differ in participants related to sex and race/ethnicity. Therefore, trialists in the field of anesthesiology should invest more effort to plan, conduct and report sex--specific and race/ethnicity results. Predominant inclusion of white participants in anesthesiology trials should be reconsidered.Cilj: Istražiti načine izvještavanja podatka o spolu i rasi/etnicitetu u randomiziranim kontroliranim pokusima objavljenim u najboljim časopisima iz područja anesteziologije. Metode: Analizirani su randomizirani kontrolirani pokusi objavljeni od 2014. do sredine 2017. godine u sedam časopisa koji se nalaze u 25% najboljih časopisa prema čimbeniku odjeka koji objavljuje baza Journal Citation Reports. Izvađeni su podatci koji se tiču izvještavanja podataka o spolu i rasi/etnicitetu. Rezultati: Analizirano je 657 pokusa. Niti jedan nije stratificirao ispitanike po spolu ili rasi/etnicitetu. Udio uključenih žena i muškaraca u prosjeku je bi podjednak. Većina uključenih ispitanika bili su bijelci. Manje od 10% uključenih radova opisalo je informacije o rasi/etnicitetu uključenih ispitanika. Rezultati koji se tiču analiza prema spolu objavljeni su u 7,9%, a rezultati analiza ovisnih o rasi/etnicitetu u 0,15% uključenih pokusa. Među 52 pokusa koja su prikazala podatke ovisno o spolu, 20 (38%) je opisalo značajne razlike u barem jednom ishodu ovisno o spolu, a u 1 (12,5%) od 8 radova koji su prikazali analize ovisno o rasi/etnicitetu prikazane su razlike prema tom aspektu. Manje od 5% analiziranih pokusa spomenulo je spol ili rasu/etnicitet u Diskusiji. Zaključak: Klinički pokusi iz najboljih anestezioloških časopisa zanemaruj aspekte spola i rase/etniciteta. Rezultati se mogu razlikovati ovisno o tome kojeg je spola i rase/etniciteta ispitanik pa je nužno u budućim istraživanjima planirati, provesti i opisati takve rezultate. Također je nužno uložiti više truda u uključivanje osoba različite rase/etniciteta u kliničke pokuse

NEWMARK ALGORITHM FOR DYNAMIC ANALYSIS WITH MAXWELL CHAIN MODEL

This paper investigates a time-stepping procedure of the Newmark type for dynamic analyses of viscoelastic structures characterized by a generalized Maxwell model. We depart from a scheme developed for a three-parameter model by Hatada et al. [1], which we extend to a generic Maxwell chain and demonstrate that the resulting algorithm can be derived from a suitably discretized Hamilton variational principle. This variational structure manifests itself in an excellent stability and a low artificial damping of the integrator, as we confirm with a mass-spring-dashpot example. After a straightforward generalization to distributed systems, the integrator may find use in, e.g., fracture simulations of laminated glass units, once combined with variationally-based fracture models