In this paper we deal with mathematical modeling of real processes that are based on preference relations in the sense that, for every pair of distinct alternatives, the processes are linked to a value of preference degree of one alternative over the other one. The use of preference relations is usual in decision making, psychology, economics, knowledge acquisition techniques for knowledge-based systems, social choice and many other social sciences. For designing useful mathematical models of such processes, it is very important to adequately represent properties of preference relations. We are mainly interested in the properties of such representations which are usually called reciprocity, consistency and transitivity. In decision making processes, the lack of reciprocity, consistency or transitivity may result in wrong conclusions. That is why it is so important to study the conditions under which these properties are satisfied. However, the perfect consistency or transitivity is difficult to obtain in practice, particularly when evaluating preferences on a set with a large number of alternatives. Under different preference representation structures, the multiplicative and additive preference representations are incorporated in the decision problem by means of a transformation function between multiplicative and additive representations. Some theoretical results on relationships between multiplicative and additive representations of preferences on finite sets are presented and some possibilities of measuring their consistency or transitivity are proposed and discussed. Illustrative numerical examples are provided.
In this paper, we deal with second-order stochastic dominance (SSD) portfolio efficiency with respect to all portfolios that can be created from a considered set of assets. Assuming scenario approach for distribution of returns several SSD portfolio efficiency tests were proposed. We introduce a δ-SSD portfolio efficiency approach and we analyze the stability of SSD portfolio efficiency and δ-SSD portfolio efficiency classification with respect to changes in scenarios of returns. We propose new SSD and δ-SSD portfolio efficiency measures as measures of the stability. We derive a non-linear and mixed-integer non-linear programs for evaluating these measures. Contrary to all existing SSD portfolio inefficiency measures, these new measures allow us to compare any two δ-SSD efficient or SSD efficient portfolios. Finally, using historical US stock market data, we compute δ-SSD and SSD portfolio efficiency measures of several SSD efficient portfolios.
a1_Mechanical properties of scaffolds seeded with mesenchymal stem cells used for cartilage repair seem to be one of the critical factors in possible joint resurfacing. In this paper, the effect of adding hyaluronic acid, hydroxyapatite nanoparticles or chitosan nanofibers into the cross-linked collagen I on the mechanical response of the lyophilized porous scaffold has been investigated in the dry state at 37 oC under tensile loading. Statistical significance of the results was evaluated using ANOVA analysis. The results showed that the addition of hyaluronic acid significantly (p<<0.05) reduced the tensile elastic modulus and enhanced the strength and deformation to failure of the modified cross-linked collagen I under the used test conditions. On the other hand, addition of hydroxyapatite nanoparticles and chitosan nanofibers, respectively, increased the elastic modulus of the modified collagen ten-fold and four-fold, respectively. Hydroxyapatite caused significant reduction in the ultimate deformation at break while chitosan nanofibers enhanced the ultimate deformation under tensile loading substantially (p<<0.05). The ultimate tensile deformation was significantly (p<<0.05) increased by addition of the chitosan nanofibers. The enhanced elastic modulus of the scaffold was translated into enhanced resistance of the porous scaffolds against mechanical load compared to scaffolds based on cross-linked neat collagen or collagen with hyaluronic acid with similar porosity. It can be concluded that enhancing the rigidity of the compact scaffold material by adding rigid chitosan nanofibers can improve the resistance of the porous scaffolds against compressive loading, which can provide more structural protection to the seeded mesenchymal stem cells when the construct is implanted into a lesion., a2_Moreover, scaffolds with chitosan nanofibers seemed to enhance cell growth compared to the neat collagen I when tested in vitro as well as the scaffold stability, extending its resorption to more than 10 weeks., J. Jančář, A. Slovíková, E. Amler, P. Krupa, H. Kecová, L. Plánka, P. Gál, A. Nečas., and Obsahuje bibliografii
Plants of Nicotiana benthamiana (Gray) (60 d old) were mechanically inoculated by a spreading of the fourth and fifth leaves with inoculum with or without plum pox potyvirus (PPV). Changes in growth parameters and selected photosynthetic characteristics were followed in control and inoculated plants in the locally affected leaves (LA) during 11 d after inoculation (DAI), in systemically affected leaves immature at time of inoculation (SAI) during 14-25 DAI, and in systemically affected leaves developed after the inoculation (SAD) during 28-39 DAI. The pure mechanical damage caused by inoculation induced a decrease in the net photosynthetic rate (PN) in LA and SAD leaves, and an increase in the steady-state value of the non-photochemical chlorophyll (Chl) fluorescence quenching qN. The qN increase appeared in certain time intervals in all measured leaves on plants, so it could be regarded as indication of a systemic reaction of plant to the local mechanical injury. The viral infection developed in LA leaves and spread to SAI and SAD leaves was documented by the ELISA-DASI method. The plant height and area of SAI and SAD leaves were lower in infected plants. The combined effect of mechanical damage and viral infection caused a decrease in PN only in LA and SAD leaves. In SAD leaves, an increased relative height of the J step (VJ) in the O-J-I-P Chl fluorescence transient together with a lower B/A band ratio of thermoluminescence glow curves reflected a damage to the acceptor side of photosystem 2 (PS2) caused by the viral infection, and a faster kinetics of the induction of the photochemical quenching coefficient qP of Chl fluorescence indicated a faster QA- re-oxidation in the remaining undamaged centres of PS2. and V. Hlaváčková ... [et al.].
Six samples of geopolymer composites (GPK) with low-dimensional microfillers, microfibre glass, basalt, carbon, microsheets of mica, microspheres of ceramics and glass were prepared. The tensile and compressive strength modulus of GPK with microfillers was measured on a P100 LabTest II press and compared to a reference sample of a non-microfillers geopolymer in order to compare the effect of the microfillers on the mechanical properties. In the same way, the tensile strength and pressure modulus of GPK with surface modified microfillers was designed to increase the adhesion of the microfillers to the geopolymer matrix. The measured values of tensile strength and pressure modulus of GPK were compared with unmodified and surface-modified reactive groups. The thermal conductivity coefficient of GPK with microfillers was measured by a direct method on the ISOMET 2014 instrument and compared to a reference sample of a non-microfillers geopolymer, in order to compare the effect of the microfillers on the thermal properties of GPK. In the same way, the thermal conductivity coefficient of GPK with surface modified microfillers was measured in order to increase the adhesion of the microfillers to the geopolymer matrix. The measured values of the GPK thermal conductivity coefficient were compared with unmodified and surface-modified microfillers. The bulk weight of the GPK samples was calculated from the measured sample weight and size and compared to the reference sample of a non-microfillers geopolymer to compare the effect of the microfillers on the GPK density. The measured GPK density values were compared with unmodified and surface-modified microfillers. Micrograph GPK digital photomicrography documented homogeneity of surface and volume of prepared samples. Nanomorphology of modified microfillers, shown by scanning electron microscopy, allowed analysis of the influence of roughness, roundness and smoothness of the samples on adhesion. and Bylo připraveno 6 vzorků geopolymerních kompozitů (GPK) s nízkorozměrnými mikroplnivy, mikrovlákny skla, čediče, uhlíku, mikrodeskami slídy, mikrosférami z keramiky a skla. Modul pevnosti v tahu a tlaku GPK s mikroplnivy byl změřen na lisu P100 LabTest II a porovnán s referenčním vzorkem geopolymeru bez mikroplniv, s cílem porovnat vliv mikroplniva na mechanické vlastnosti. Stejným způsobem byl změřen modul pevnosti v tahu a tlaku GPK s povrchově modifikovanými mikroplnivy s cílem zvýšení adheze mikroplniva ke geopolymerní matrici. Byly porovnány změřené hodnoty modulu pevnosti v tahu a tlaku GPK s mikroplnivy nemodifikovanými a povrchově modifikovanými reaktivními skupinami. Součinitel tepelné vodivosti GPK s mikroplnivy byl změřen přímou metodou na přístroji ISOMET 2014 a porovnán s referenčním vzorkem geopolymeru bez mikroplniv, s cílem porovnat vliv mikroplniva na tepelné vlastnosti GPK. Stejným způsobem byl změřen součinitel tepelné vodivosti GPK s povrchově modifikovanými mikroplnivy s cílem zvýšení adheze mikroplniva ke geopolymerní matrici. Byly porovnány změřené hodnoty součinitele tepelné vodivosti GPK s mikroplnivy nemodifikovanými a povrchově modifikovanými. Objemová hmotnost vzorků GPK byla vypočtena ze změřené hmotnosti a rozměrů vzorků a porovnána s referenčním vzorkem geopolymeru bez mikroplniv, s cílem porovnat vliv mikroplniva na hustotu GPK. Byly porovnány změřené hodnoty hustoty GPK s mikroplnivy nemodifikovanými a povrchově modifikovanými. Digitální mikrofotografie GPK s mikroplnivy dokumentovala homogenitu povrchu a objemu připravených vzorků. Nanomorfologie modifikovaných mikroplniv, zobrazená rastrovacím elektronovým mikroskopem, umožnila analýzu vlivu drsnosti, kulatosti a hladkosti vzorků na adhezi.
Six samples of foam geopolymer composites (GPK) with low-dimensional microfillers, microfibre glass, basalt, carbon, microsheets of mica, microspheres of ceramics and glass were prepared. The tensile and compressive strength modulus of GPK with microfillers was measured on a P100 LabTest II press and compared to a reference sample of a non-microfillers geopolymer in order to compare the effect of the microfillers on the mechanical properties. In the same way, the tensile strength and pressure modulus of GPK with surface modified microfillers was designed to increase the adhesion of the microfillers to the geopolymer matrix. The measured values of tensile strength and pressure modulus of GPK were compared with unmodified and surface-modified reactive groups. The thermal conductivity coefficient of GPK with microfillers was measured by a direct method on the ISOMET 2014 instrument and compared to a reference sample of a nonmicrofillers geopolymer, in order to compare the effect of the microfillers on the thermal properties of GPK. In the same way, the thermal conductivity coefficient of GPK with surface modified microfillers was measured in order to increase the adhesion of the microfillers to the geopolymer matrix. The measured values of the GPK thermal conductivity coefficient were compared with unmodified and surface-modified microfillers. The bulk weight of the GPK samples was calculated from the measured sample weight and size and compared to the reference sample of a non-microfillers geopolymer to compare the effect of the microfillers on the GPK density. The measured GPK density values were compared with unmodified and surface-modified microfillers. Micrograph GPK digital photomicrography documented homogeneity of surface and volume of prepared samples. Nanomorphology of modified microfillers, shown by scanning electron microscopy, allowed analysis of the influence of roughness, roundness and smoothness of the samples on adhesion. and Bylo připraveno 6 vzorků pěnových geopolymerních kompozitů (GPK) s nízkorozměrnými mikroplnivy, mikrovlákny skla, čediče, uhlíku, mikrodeskami slídy, mikrosférami z keramiky a skla. Modul pevnosti v tahu a tlaku GPK s mikroplnivy byl změřen na lisu P100 LabTest II a porovnán s referenčním vzorkem geopolymeru bez mikroplniv, s cílem porovnat vliv mikroplniva na mechanické vlastnosti. Stejným způsobem byl modul pevnosti v tahu a tlaku GPK s povrchově modifikovanými mikroplnivy s cílem zvýšení adheze mikroplniva ke geopolymerní matrici. Byly porovnány změřené hodnoty modulu pevnosti v tahu a tlaku GPK s mikroplnivy nemodifikovanými a povrchově modifikovanými reaktivními skupinami. Součinitel tepelné vodivosti GPK s mikroplnivy byl změřen přímou metodou na přístroji ISOMET 2014 a porovnán s referenčním vzorkem geopolymeru bez mikroplniv, s cílem porovnat vliv mikroplniva na tepelné vlastnosti GPK. Stejným způsobem byl změřen součinitel tepelné vodivosti GPK s povrchově modifikovanými mikroplnivy s cílem zvýšení adheze mikroplniva ke geopolymerní matrici. Byly porovnány změřené hodnoty součinitele tepelné vodivosti GPK s mikroplnivy nemodifikovanými a povrchově modifikovanými. Objemová hmotnost vzorků GPK byla vypočtena ze změřené hmotnosti a rozměrů vzorků a porovnána s referenčním vzorkem geopolymeru bez mikroplniv, s cílem porovnat vliv mikroplniva na hustotu GPK. Byly porovnány změřené hodnoty hustoty GPK s mikroplnivy nemodifikovanými a povrchově modifikovanými. Digitální mikrofotografie GPK s mikroplnivy dokumentovala homogenitu povrchu a objemu připravených vzorků. Nanomorfologie modifikovaných mikroplniv, zobrazená rastrovacím elektronovým mikroskopem, umožnila analýzu vlivu drsnosti, kulatosti a hladkosti vzorků na adhezi.
Edge preparation becomes of the most important parameter which significantly influenced final practical application of tools. This article summarizes commonly used and also relatively new ways of preparation of the tools surface before and after PVD coating application. These methods are explained with respect to their advantages and limits of their application. and Odjehlení se stává nejdůležitějším parametrem, který má významný vliv na praktickou upotřebitelnost nástrojů. Článek shrnuje běžně používané a rovněž poměrně nové způsoby povrchové úpravy nástrojů před PVD povlakováním a po něm.
In the contribution the results on the combination of ion sputtering and scattering processes for achieving enhanced complementary information on the analyzed multilayer are reported. Physical background of ion-solid interactions is discussed. Specifically, the combination of SIMS and TOF-LEIS techniques will be introduced. and V tomto článku je diskutována problematika interakce iontů s pevnou látkou. Podrobněji je diskutována možnost využití mechanických vlastností iontů k analýze 2D nanostruktur (vrstev s tloušťkou v jednotkách nanometrů) pomocí metod SIMS a TOF-LEIS.
The herbicides diuron, fluridone, or sulcotrione differently reduced chlorophyll (Chl) and carotenoid (Car) contents. Four days after herbicide treatment, application of sulcotrione resulted in a Chl/Car ratio of 5.88, similar as in untreated controls; diuron resulted in ratio of 5.24, while fluridone induced a greater diminution in Car contents and yielded a final ratio of 7.02. Sulcotrione induced a more rapid decrease than fluridone did in the quantum yield of photosystem 2 (PS2) as monitored by Chl fluorescence. Measurements of DPIP reduction with isolated thylakoids indicated that sulcotrione was a more effective inhibitor of the Hill reaction in cucumber, a herbicide sensitive species, than in maize, a herbicide-insensitive species. These results are consistent with the view that inhibition of electron transport via reduction in plastoquinone contents in plants leads to the major herbicidal effect of sulcotrione in mature green tissues. and J.-S. Kim ... [et al.].