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151.
Mohammad Azad Igor Chikalov Shahid Hussain Mikhail Moshkov Beata Zielosko 《Entropy (Basel, Switzerland)》2021,23(12)
Conventional decision trees use queries each of which is based on one attribute. In this study, we also examine decision trees that handle additional queries based on hypotheses. This kind of query is similar to the equivalence queries considered in exact learning. Earlier, we designed dynamic programming algorithms for the computation of the minimum depth and the minimum number of internal nodes in decision trees that have hypotheses. Modification of these algorithms considered in the present paper permits us to build decision trees with hypotheses that are optimal relative to the depth or relative to the number of the internal nodes. We compare the length and coverage of decision rules extracted from optimal decision trees with hypotheses and decision rules extracted from optimal conventional decision trees to choose the ones that are preferable as a tool for the representation of information. To this end, we conduct computer experiments on various decision tables from the UCI Machine Learning Repository. In addition, we also consider decision tables for randomly generated Boolean functions. The collected results show that the decision rules derived from decision trees with hypotheses in many cases are better than the rules extracted from conventional decision trees. 相似文献
152.
Anna Stochmal Barbara Moniuszko-Szajwaj Jerzy Zuchowski ukasz Pecio Bogdan Kontek Malgorzata Szumacher-Strabel Beata Olas Adam Cieslak 《Molecules (Basel, Switzerland)》2022,27(3)
It is not easy to find data in the scientific literature on the quantitative content of individual phytochemicals. It is possible to find groups of compounds and even individual compounds rather easily, but it is not known what their concentration is in cultivated or wild plants. Therefore, the subject of this study was to determine the content of individual compounds in the new Paulownia species, Oxytree, developed in a biotechnology laboratory in 2008 at La Mancha University in Spain. Six secondary metabolites were isolated, and their chemical structure was confirmed by spectral methods. An analytical method was developed, which was then used to determine the content of individual compounds in leaves, twigs, flowers and fruits of Paulownia Clon in Vitro 112®. No flavonoids were found in twigs and fruits of Oxytree, while the highest phenylethanoid glycosides were found in twigs. In this study, we also focused on biological properties (anticoagulant or procoagulant) of extract and four fractions (A–D) of different chemical composition from Paulownia Clon in Vitro 112 leaves using whole human blood. These properties were determined based on the thrombus-formation analysis system (T-TAS), which imitates in vivo conditions to assess whole blood thrombogenecity. We observed that three fractions (A, C and D) from leaves decrease AUC10 measured by T-TAS. In addition, fraction D rich in triterpenoids showed the strongest anticoagulant activity. However, in order to clarify the exact mechanism of action of the active substances present in this plant, studies closer to physiological conditions, i.e., in vivo studies, should be performed, which will also allow to determine the effects of their long-term effects. 相似文献
153.
Evaluation of high-field asymmetric waveform ion mobility spectrometry mass spectrometry for the analysis of the mycotoxin zearalenone 总被引:1,自引:0,他引:1
A high-field asymmetric waveform ion mobility spectrometry (FAIMS)-based method for the determination of the mycotoxin zearalenone (ZON) and its metabolites α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), and β-zearalanol (β-ZAL), in a cornmeal (maize) matrix is described. Detection limits achieved using the FAIMS device coupled with electrospray ionization (ESI) and mass spectrometric (MS) detection are 0.4 ng mL−1 for ZON and 3 ng mL−1 for α-ZOL + β-ZOL, and β-ZAL. This represents a significant improvement when compared to detection limits determined using ESI-MS or ESI-tandem mass spectrometry (MSMS) analytical methods. The developed flow-injection (FIA)-ESI-FAIMS-MS method was applied to reference materials ERM-BC-716 and ERM-BC-717 certified for ZON and excellent agreement with the certified values was observed. 相似文献
154.
Beata Strycharz 《Mathematical Methods in the Applied Sciences》1998,21(10):969-983
We study the problem of the scattering by a periodic, inhomogeneous, penetrable medium. Using the Dirichlet-to-Neumann operator from the classical formulation of the problem we derive a variational equation and give regularity result to show the equivalence of both formulations. We present certain uniqueness results, which by the Fredholm alternative yield existence of the solution and its continuous dependence on the incoming wave. We prove existence of a solution for special incident waves even if there is no uniqueness. A result about analytical dependence of the solution on the wave number and the incident angle is given. © 1998 B. G. Teubner Stuttgart—John Wiley & Sons, Ltd. 相似文献
155.
Nanoparticles of tungsten trioxide, WO3, are used to enhance the luminescence emission intensity of terbium(III) ions embedded in a silica matrix. Optically active components have been incorporated into silica xerogel by impregnation of silica xerogel immersed firstly in WO3 sol and subsequently in a solution with Tb(III). Photoluminescence studies make it possible to describe a plausible mechanism of the Tb(III) enhanced luminescence that could be attributed to energy transfer via excited WO3 nanoparticles to Tb(III) ions in the system: Tb(III) ions–WO3 nanocrystals–SiO2. The effect related to WO3 nanoparticles of various sizes influences not only changes in the emission intensity and band shifting of WO3 nanostructures but also the same spectral parameters of the emitting Tb(III) ions. 相似文献
156.
The effects of baffling of an agitated vessel on the production of floating particles suspension are presented in this paper.
Critical agitator speed, needed for particles dispersion in a liquid agitated in a vessel of the inner diameter of 0.295 m,
was determined. The just drawdown agitator speeds were defined analogously to the Zwietering criterion. Specific agitation
energy was calculated from the power consumption experimental data obtained by means of the strain gauge method. The experiments
were carried out for twelve configurations of the baffles differing in number, length and their arrangement in the vessels.
The following high-speed impellers were used: up- and downpumping six blade pitched blade turbines, Rushton turbine, and propeller.
The impeller was located in the vessel in the height equal to two-thirds or one-third of the vessel diameter from the bottom
of the vessel. The results were described in the form of a dimensionless equation.
Presented at the 35th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 26–30 May
2008. 相似文献
157.
The kinetics of the oxidation of 4‐isopropylbiphenyl ( 1 ) in the liquid phase by oxygen to 1‐(1,1′‐biphenyl‐4‐yl)‐1‐methylethyl hydroperoxide ( 2 ) was investigated. The oxidizability of 1 in the temperature range from 60°C to 120°C and the overall energy activation of oxidation were determined. Long‐term oxidation of 1 to 2 in the temperature range of 80–120°C was investigated, and the yield and selectivity of the process were determined. Pure 2 was obtained, and its properties were defined. 4‐Hydroxybiphenyl was obtained as a result of the acidic decomposition of 2 . © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 527–532, 2008 相似文献
158.
György Gergely Miklós Menyhard Attila Sulyok Sándor Gurban Beata Lesiak Aleksander Jablonski Andrzej Kosinski József Toth Dezső Varga 《Central European Journal of Physics》2007,5(2):188-200
The inelastic mean free path (IMFP) of electrons was determined experimentally for selected polyaniline and polyacetylene
samples with Ag and Ni references using elastic peak electron spectroscopy (EPES). The surface composition was determined
by XPS and density by helium pycnometry. The high resolution hemispherical ESA-31 and ADES-400 spectrometers were used for
measurements in the energy range E = 0.5–3.0 keV and E =0.4 − 1.6 keV, respectively. The integrated elastic peak intensity ratios for sample and reference were calculated using
the Monte Carlo (MC) algorithm based on the electron elastic scattering cross-sections database NIST SRD64 version 3.1 and
applying TPP-2M IMFPs for polymers. Surface excitation parameters (SEP) and material parameters (
ach
) for polymers were determined, using the model of Chen, from comparison of measured and MC calculated elastic peak intensity
ratios. These corrections proved to be efficient in decreasing the percentage deviations between the obtained IMFPs and the
TPP-2M formula IMFPs. The elastic peak of hydrogen was observed in the EPES spectra of polymers. The experimental contribution
of the hydrogen to the total elastic peak was 0.58%, while this value obtained from the MC simulations was 1.98%.
相似文献
159.
Wojciech Bartoszek Beata Kuna 《Proceedings of the American Mathematical Society》2005,133(7):2119-2129
We show that the set of those Markov operators on the Schatten class such that , where is one-dimensional projection, is norm open and dense. If we require that the limit projections must be on strictly positive states, then such operators form a norm dense . Surprisingly, for the strong operator topology operators the situation is quite the opposite.
160.
A new interpretation of serum albumin surface passivation 总被引:1,自引:0,他引:1
Sweryda-Krawiec B Devaraj H Jacob G Hickman JJ 《Langmuir : the ACS journal of surfaces and colloids》2004,20(6):2054-2056