63 research outputs found
Octahedral conversion of a-SiO2-host matrix by pulsed ion implantation
This is the abstract. The results of measurements of X-ray photoelectron
spectra (XPS) of a-SiO2-host material after pulsed implantation with [Mn+] and
[Co+, Mn+]-ions as well as DFT-calculations are presented. The low-energy shift
is found in XPS Si 2p and O 1s core-levels of single [Mn+] and dual [Co+, Mn+]
pulsed ion-implanted a-SiO2 (E = 30 keV, D = 2*10^17 cm^-2) with respect to
those of untreated a-SiO2.The similar changes are found in XPS Si 2p and O 1s
of stishovite compared to those of quartz. This means that the pulsed
ion-implantation induces the local high pressure effect which leads to an
appearance of SiO6-structural units in alpha-SiO2 host, forming
"stishovite-like" local atomic structure. This process can be described within
electronic bonding transition from the four-fold "quartz-like" to six-fold
"stishovite-like" high-pressure phase in SiO2 host-matrix. It is found that
such octahedral conversion depends on the fluence and starts with doses higher
than D = 3*10^16 cm^-2.Comment: 15 pages, 6 figures, 1 table, accepted in phys. stat. solidi (b
Instance reduction for one-class classification
Instance reduction techniques are data preprocessing methods originally developed to enhance the nearest neighbor rule for standard classification. They reduce the training data by selecting or generating representative examples of a given problem. These algorithms have been designed and widely analyzed in multi-class problems providing very competitive results. However, this issue was rarely addressed in the context of one-class classification. In this specific domain a reduction of the training set may not only decrease the classification time and classifier’s complexity, but also allows us to handle internal noisy data and simplify the data description boundary. We propose two methods for achieving this goal. The first one is a flexible framework that adjusts any instance reduction method to one-class scenario by introduction of meaningful artificial outliers. The second one is a novel modification of evolutionary instance reduction technique that is based on differential evolution and uses consistency measure for model evaluation in filter or wrapper modes. It is a powerful native one-class solution that does not require an access to counterexamples. Both of the proposed algorithms can be applied to any type of one-class classifier. On the basis of extensive computational experiments, we show that the proposed methods are highly efficient techniques to reduce the complexity and improve the classification performance in one-class scenarios
Alterations in vasomotor control of coronary resistance vessels in remodelled myocardium of swine with a recent myocardial infarction
The mechanism underlying the progressive deterioration of left ventricular (LV) dysfunction after myocardial infarction (MI) towards overt heart failure remains incompletely understood, but may involve impairments in coronary blood flow regulation within remodelled myocardium leading to intermittent myocardial ischemia. Blood flow to the remodelled myocardium is hampered as the coronary vasculature does not grow commensurate with the increase in LV mass and because extravascular compression of the coronary vasculature is increased. In addition to these factors, an increase in coronary vasomotor tone, secondary to neurohumoral activation and endothelial dysfunction, could also contribute to the impaired myocardial oxygen supply. Consequently, we explored, in a series of studies, the alterations in regulation of coronary resistance vessel tone in remodelled myocardium of swine with a 2 to 3-week-old MI. These studies indicate that myocardial oxygen balance is perturbed in remodelled myocardium, thereby forcing the myocardium to increase its oxygen extraction. These perturbations do not appear to be the result of blunted β-adrenergic or endothelial NO-mediated coronary vasodilator influences, and are opposed by an increased vasodilator influence through opening of KATP channels. Unexpectedly, we observed that despite increased circulating levels of noradrenaline, angiotensin II and endothelin-1, α-adrenergic tone remained negligible, while the coronary vasoconstrictor influences of endogenous endothelin and angiotensin II were virtually abolished. We conclude that, early after MI, perturbations in myocardial oxygen balance are observed in remodelled myocardium. However, adaptive alterations in coronary resistance vessel control, consisting of increased vasodilator influences in conjunction with blunted vasoconstrictor influences, act to minimize the impairments of myocardial oxygen balance
Review of Computer Programs Dedicated to the Design of Electronic Systems. Characteristics of the GeckoCIRCUITS Environment
Rozwój technologii wytwarzania układów elektronicznych, a także coraz szerszy zakres ich zastosowań, prowadzi do zapotrzebowania na rozwiązania wspomagające ich projektowanie. W artykule dokonano przeglądu wybranych rozwiązań dedykowanych projektowaniu układów elektronicznych. Skoncentrowano się na rozwiązaniach opartych na projektowaniu komputerowym, porównując wybrane środowiska programowe. W szczególności uwagę poświęcono środowisku GeckoCIRCUITS, które omówiono na przykładzie projektu układu przekształtnika podwyższającego napięcie (boost converter).The development of electronics manufacturing technologies, as well as increasingly broad range of their applications, leads to an increase in the demand for solutions that support their design process. The article reviews selected solutions dedicated to the design of electronic circuits and focuses on computed-based solutions, comparing the selected software environments. Particular attention has been paid to the GeckoCIRCUITS environment, which has been discussed basing on example of an electronic boost converter circuit design
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Searching for the Cause: Search Behavior in Explanation of Causal Chains
Understanding cause and effect relationships gives power to produce desired effects and avoid negative outcomes. Despite the power of causal explanations, people often lack full understanding of how causes relate to or produce their effects. In two experiments, we explored how people search for information to enrich their causal explanations of real-world phenomena when given the chance. Participants completed an information search task that provided a causal relationship where they could seek out mechanistic information at different steps between the cause and the effect. We measured where people searched in the causal chain of events that made the explanation. We found that when allowed to search freely (Experiment 1) or when instructed that they must search for information (Experiment 2) participants consistently sought out information closest to the root cause in the explanation. We discuss implications for how to improve the teaching of new explanations to maximize the informational desires of the learner
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Spatial-Numeric Associations Distort Estimates of Causal Strength
When individuals provide magnitude estimates using numeric scales, they may be influenced by spatio-numeric biases.In Western, English-speaking cultures smaller magnitudes are associated with the left side of space and larger with theright. We demonstrated the impact of spatial-numeric associations on judgments of causal strength in two trial-by-trialcausal learning experiments. Causes appeared on either the left or right side of a computer screen. In Experiment 1,participants made casual judgments using a number line either increasing in magnitude from left to right or decreasingin magnitude from left to right. In Experiment 2, participants made judgments using a non-linear circular target with thedepth of hue saturation representing causal strength. In Experiment 1, participants gave higher causal ratings to causesappearing in the space associated with larger numbers on the number line. These influences disappeared when the linearityof spatial-numeric associations was removed in Experiment 2
Kvantovyjj izmeritel' fotosynteticheski aktivnojj radiacii
A Siemens BPx90B silicon photodiode has been applied as the detector. In order to optimalize the sensor characteristics a set of correcting filters was used. The measurement error was less than 3% for the sum radiation and less than 6% for artificial sources of light.Detektorem promieniowania jest fotodioda krzemowa BPx90B (Siemens). W celu uzyskania krzywej czułości spektralnej czujnika możliwie zbliżonej do idealnej charakterystyki kwantowej zastosowano zestaw filtrów korekcyjnych. Błąd pomiaru jest niższy niż 3% dla promieniowania słonecznego i mniejszy niż 6% dla sztucznych źródeł światła.Детектором радиации является кренмиевый фотодиод ВРХ90В (Сименс) Для получения кривой спектральной чувствительности датчика, возможно близкой к идеальной квантовой характеристике, применили набор коррекционных фильтров (рис. 1). Ошибка измерения меньше 3% для солнечной радиации и меньше 6% для искусственных источников света
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Transferring Novel Causal Knowledge
Knowledge of cause and effect allows people to navigate and understand the complex systems of the world. Despite the importance of causal knowledge to everyday reasoning, little is known about how people transfer causal knowledge learned in one situation to novel contexts. In two experiments, we examine when people choose to generalize two types of causal knowledge, causal mechanisms (Experiment 1) and causal strength (Experiment 2), across various domains. We find that people willingly transfer causal knowledge to novel contexts when the entities in those contexts share high categorical relatedness with the source of the causal knowledge. The extent to which people are willing to transfer causal knowledge decreases as category similarity decreases. We discuss future research that could delineate the boundaries of causal transfer
Ocena wpływu czynników konstytucjonalnych na dzienne spożycie selenu na przykładzie mieszkańców województwa pomorskiego
In the current work, dietary intake of selenium was studied among adults residents of Pomeranian District. Concentration of selenium in diet samples was determined using Hydride Generation Atomic Absorption Spectrometry (HGAAS) technique after microwave digestion. The analyses of the 1 - day food ratios showed that the participants consumed insufficient levels of selenium with reference to Recommended Dietary Allowance what may constitute a risk for the deficiency of this element in human body. Moreover, the statistical analysis demonstrated a significant effect of the gender, age, and body mass index upon the dietary intake of selenium.W pracy dokonano oceny realizacji zapotrzebowania na selen w całodziennych racjach pokarmowych pobranych metodą podwójnej porcji wśród mieszkańców województwa pomorskiego. Oznaczanie Se przeprowadzono techniką generowania wodorków w połączeniu z absorpcyjną spektrometrią atomową (HGAAS) po uprzedniej mineralizacji próbek żywności. Analiza całodziennych racji pokarmowych pozwoliła na stwierdzenie, że ilość selenu przyjmowanego wraz z dietą jest niewystarczająca i może stanowić duże ryzyko niedoboru tego pierwiastka w organizmie. Ponadto, przeprowadzona analiza statystyczna wykazała wpływ płci, wieku oraz wskaźnika masy ciała na zawartość selenu w badanych próbkach żywnościowych
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