3,972 research outputs found

    Quantum systems as classical systems

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    A characteristical property of a classical physical theory is that the observables are real functions taking an exact outcome on every (pure) state; in a quantum theory, at the contrary, a given observable on a given state can take several values with only a predictable probability. However, even in the classical case, when an observer is intrinsically unable to distinguish between some distinct states he can convince himself that the measure of its ''observables'' can have several values in a random way with a statistical character. What kind of statistical theory is obtainable in this way? It is possible, for example, to obtain exactly the statistical previsions of quantum mechanics? Or, in other words, can a physical system showing a classical behaviour appear to be a quantum system to a confusing observer? We show that from a mathematical viewpoint it is not difficult to produce a theory with hidden variables having this property. We don't even try to justify in physical terms the artificial construction we propose; what we do is to give a general and rigorous argument showing how the interplay between the classical and quantum mechanics we offer is interpretable as the difference between an imaginary very expert observer and another nonexpert observer. This proves also that besides the well known theorems concerning the impossibility of hidden variables (cfr. Von Neumann [Neu] and Jauch-Piron [J-P]) there is also room for a result in favor of the possibility.Comment: late

    Financial Development and Income Inequality: A Panel Data Approach

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    We analyze the link between financial development and income inequality for a broad unbalanced dataset of up to 138 developed and developing countries over the years 1960 to 2008. Using credit-to-GDP as a measure of financial development, our results reject theoretical models predicting a negative impact of financial development on income inequality measured by the Gini coefficient. Controlling for country fixed effects and GDP per capita, we find that financial development has a positive effect on income inequality. These results are robust to different measures of financial development, econometric specifications, and control variables.financial development, income inequality, global, panel analysis

    Orbital moment in CoO and in NiO

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    The total, orbital and spin moment of the Co2+ ion in CoO has been calculated within the quasi-atomic approach with taking into account strong correlations, crystal-field interactions and the intra-atomic spin-orbit coupling. The orbital moment of 1.39 \mu B amounts at 0 K, in the magnetically-ordered state, to more than 34% of the total moment (4.01 \mu B). The same calculations yield for NiO the orbital and total moment of 0.46 \mu B and 2.45 \mu B, respectively. PACS No: 71.70.E; 75.10.D Keywords: 3d magnetism, crystal field, spin-orbit coupling, orbital moment, CoO, NiOComment: 6 pages in tex+3 figs, submitted for PNSXM-03, Venic

    Influence of different fat emulsions with 10 or 20% MCT/LCT or LCT on lipoproteins in plasma of patients after abdominal surgery

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    In patients after elective abdominal surgery, different fat emulsions were used to compare their efficacy in total parenteral nutrition and in normalizing plasma lipoprotein levels. In five different groups with 5 patients each, half of the nonprotein calories were given as medium-chain triglycerides/ long-chain triglycerides (1:1) or as long-chain triglycerides alone in 10 or 20% fat emulsions or as glucose alone in a control group for 7 days. After surgery, an initial decrease of all plasma lipoprotein components was followed by a different behavior of glyceride-glycerol, cholesterol, phospholipids, and apolipoproteins. Glyceride-glycerol in very-low-density lipoproteins and high-density lipoproteins is increasing during infusion of fat emulsions and decreasing during overnight interruption of infusions. After the 7-day infusion period, there was no significant difference in very-low-density lipoprotein glyceride-glycerol as compared with the values before different infusions, Low-density lipoprotein cholesterol is reaching and exceeding preoperative concentrations between the 4th and the 7th day, most during infusion of 10% fat emulsion and especially due to an increase of free cholesterol, High-density lipoprotein cholesterol and apolipoprotein A-I reach preoperative levels during infusion of fat emulsions but not with glucose alone, Higher than preoperative values are reached in phospholipids with all fat infusions already on day 4, Abnormal lipoprotein X occurred least with the medium-chain/long-chain triglyceride 20% fat-infusion. This fat emulsion is suggested as having the best normalizing effect on plasma lipoproteins and best tolerance in patients after surgery

    Homologies in human and Macasa fuscata chromosomes revealed by in situ suppression hybridization with human chromosome specific DNA libraries

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    We established chromosomal homologies between all chromosomes of the human karyotype and that of an old world monkey (Macaca fuscata) by chromosomal in situ suppression (CISS) hybridization with human chromosome specific DNA libraries. Except for the human chromosome 2 library and limited cross-hybridization of X and Y chromosome libraries all human DNA libraries hybridized to single GTG-banded macaque chromosomes. Only three macaque chromosomes (2, 7, 13) were each hybridized by two separate human libraries (7 and 21, 14 and 15, 20 and 22 respectively). Thus, an unequivocally high degree of synteny between human and macaque chromosomes has been maintained for more than 20 million years. As previously suggested, both Papionini (macaques, baboons, mandrills and cercocebus monkeys, all of which have nearly identical karyotypes) and humans are chromosomally conservative. The results suggest, that CISS hybridization can be expected to become an indispensable tool in comparative chromosome and gene mapping and will help clarify chromosomal phylogenies with speed and accuracy

    The rat race and working time regulation

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    To what extent, if at all, should a just society adopt public policies that regulate and limit the amount of time people work? Attempts to answer this question face a dilemma: Either, we can adopt a laissez-faire view, according to which governments must refrain from imposing working time policies on the labour market. But this view generates a situation in which many citizens experience deep regret about the balance between work and leisure in their lives. Or, we can endorse an interventionist view that advocates government imposition of working time policies. However, such a view appears to be objectionably perfectionist insofar as it imposes on citizens a particular conception of the ideal balance between work and leisure. This article proposes a way out of this dilemma. It shows that the interventionist view can be defended on the anti-perfectionist grounds that this helps address a collective action problem in the labour market – the working time rat race. Employers often use working time as a proxy for their employees’ productivity and commitment. Those who work particularly long hours are often awarded benefits such as raises or promotions or are spared from dismissals. This makes it individually rational for each worker to work extra hours in an attempt to outcompete colleagues. However, if many workers pursue this strategy, it loses its effectiveness. Workers with preferences for more leisure have a claim to state intervention to remove the rat race when this doesn’t impose disproportionate harm on third parties. </jats:p

    Trajectory optimization based on recursive B-spline approximation for automated longitudinal control of a battery electric vehicle

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    Diese Arbeit beschreibt ein neuartiges Verfahren zur linearen und nichtlinearen gewichteten Kleinste-Quadrate-Approximation einer unbeschränkten Anzahl von Datenpunkten mit einer B-Spline-Funktion. Das entwickelte Verfahren basiert auf iterativen Algorithmen zur Zustandsschätzung und sein Rechenaufwand nimmt linear mit der Anzahl der Datenpunkte zu. Das Verfahren ermöglicht eine Verschiebung des beschränkten Definitionsbereichs einer B-Spline-Funktion zur Laufzeit, sodass der aktuell betrachtete Datenpunkt ungeachtet des anfangs gewählten Definitionsbereichs bei der Approximation berücksichtigt werden kann. Zudem ermöglicht die Verschiebeoperation die Reduktion der Größen der Matrizen in den Zustandsschätzern zur Senkung des Rechenaufwands sowohl in Offline-Anwendungen, in denen alle Datenpunkte gleichzeitig zur Verarbeitung vorliegen, als auch in Online-Anwendungen, in denen in jedem Zeitschritt weitere Datenpunkte beobachtet werden. Das Trajektorienoptimierungsproblem wird so formuliert, dass das Approximationsverfahren mit Datenpunkten aus Kartendaten eine B-Spline-Funktion berechnet, die die gewünschte Geschwindigkeitstrajektorie bezüglich der Zeit repräsentiert. Der Rechenaufwand des resultierenden direkten Trajektorienoptimierungsverfahrens steigt lediglich linear mit der unbeschränkten zeitlichen Trajektorienlänge an. Die Kombination mit einem adaptiven Modell des Antriebsstrangs eines batterie-elektrischen Fahrzeugs mit festem Getriebeübersetzungsverhältnis ermöglicht die Optimierung von Geschwindigkeitstrajektorien hinsichtlich Fahrzeit, Komfort und Energieverbrauch. Das Trajektorienoptimierungsverfahren wird zu einem Fahrerassistenzsystem für die automatisierte Fahrzeuglängsführung erweitert, das simulativ und in realen Erprobungsfahrten getestet wird. Simulierte Fahrten auf der gewählten Referenzstrecke benötigten bis zu 3,4 % weniger Energie mit der automatisierten Längsführung als mit einem menschlichen Fahrer bei derselben Durchschnittsgeschwindigkeit. Für denselben Energieverbrauch erzielt die automatisierte Längsführung eine 2,6 % höhere Durchschnittsgeschwindigkeit als ein menschlicher Fahrer
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