2,068 research outputs found

    Most Efficient Homogeneous Volatility Estimators

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    We present a comprehensive theory of homogeneous volatility (and variance) estimators of arbitrary stochastic processes that fully exploit the OHLC (open, high, low, close) prices. For this, we develop the theory of most efficient point-wise homogeneous OHLC volatility estimators, valid for any price processes. We introduce the "quasi-unbiased estimators", that can address any type of desirable constraints. The main tool of our theory is the parsimonious encoding of all the information contained in the OHLC prices for a given time interval in the form of the joint distributions of the high-minus-open, low-minus-open and close-minus-open values, whose analytical expression is derived exactly for Wiener processes with drift. The distributions can be calculated to yield the most efficient estimators associated with any statistical properties of the underlying log-price stochastic process. Applied to Wiener processes for log-prices with drift, we provide explicit analytical expressions for the most efficient point-wise volatility and variance estimators, based on the analytical expression of the joint distribution of the high-minus-open, low-minus-open and close-minus-open values. The efficiency of the new proposed estimators is favorably compared with that of the Garman-Klass, Roger-Satchell and maximum likelihood estimators.Comment: 46 pages including 17 figure

    Adatom incorporation and step crossing at the edges of 2D nanoislands

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    Adatom incorporation into the ``faceted'' steps bordering the 2D nanoislands is analyzed. The step permeability and incorporation coefficients are derived for some typical growth situations. It is shown that the step consisting of equivalent straight segments can be permeable even in the case of fast egde migration if there exist factors delaying creation of new kinks. The step consisting of alternating rough and straight segments may be permeable if there is no adatom transport between neighboring segments through the corner diffusion.Comment: 3 pages, one figur

    Formation of phase structure in the system Ti-3Al at the stage of secondary structurization at synthesis in the mode of thermal explosion

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    Features of phase formation processes in the system Ti-3Al at realization of self-extending synthesis in the mode of thermal explosion have been established with use of technological reactor enabling instant switching-off of the heating source. The analysis of synthesis finished products allows to draw a conclusion that phase structure of charge is abnormally depends on sizes of titanium particles. The single-phase product corresponding to initial stoichiometry is synthesized on fine and large fractions for the induction period. On intermediate fraction the product of synthesis is multiphas

    Formation of phase structure in the system Ti-3Al at the stage of secondary structurization at synthesis in the mode of thermal explosion

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    Features of phase formation processes in the system Ti-3Al at realization of self-extending synthesis in the mode of thermal explosion have been established with use of technological reactor enabling instant switching-off of the heating source. The analysis of synthesis finished products allows to draw a conclusion that phase structure of charge is abnormally depends on sizes of titanium particles. The single-phase product corresponding to initial stoichiometry is synthesized on fine and large fractions for the induction period. On intermediate fraction the product of synthesis is multiphas

    Spurious trend switching phenomena in financial markets

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    The observations of power laws in the time to extrema of volatility, volume and intertrade times, from milliseconds to years reported by Preis et al. (2010, 2011), are shown to result straightforwardly from the selection of biased statistical subsets of realizations in otherwise featureless processes such as random walks. The bias stems from the selection of price peaks that imposes a condition on the statistics of price change and of trade volumes that skew their distributions. For the intertrade times, the extrema and power laws results from the format of transaction dat

    Model-oriented co-design of homogeneous computing systems

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    This article proposes an approach to the construction of a technological platform for designing function-oriented processors (FOP) built on the basis of homogeneous computing environments (OVS). A feature of the proposed approach is the use of co-design - a simultaneous and interconnected design of hardware (HW) and software (SW) FOP components. The paper presents proposals for the implementation of this approach, based on the use of the prin-ciple of model-based design, which allows you to make the co-design process iterative and effectively distribute data processing procedures between HW and SW - components of FOP. Based on the consideration of the experience in implementing such solutions, the paper presents the composition of functional subsystems of technological platforms, a diagram of information interaction between these subsystems based on intensive using of web-technologies at all stages of the design and operation of FOP. Β© 2019 Tomsk State University. All rights reserved

    Formation of Regional Public Organizations in Last Quarter of XIX β€” Early XX Century (Tomsk Province)

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    The activity of officials on the formation of public non-political organizations of the Tomsk province in the last quarter of the XIX β€” early XX centuries is considered. The picture of the current state of research of public organizations and officials of the Russian Empire is presented. Based on the analysis of a number of published and unpublished sources, examples of the participation of representatives of the Tomsk administration in the process of creating various societies are revealed. The features of interaction of officials with representatives of the local society (scientists, political exiles, merchants, industrialists), as well as with city government bodies are highlighted. The main forms of the contribution of the Tomsk bureaucracy to the creation of societies are determined: the development of a charter, a petition to the state to open an organization, a search for like-minded people, and financial support. The author establishes the main reasons for the participation of employees of administrative institutions of the Tomsk province in the formation of new societies: job responsibilities, joint initiative with members of the public, personal interest. A correlation was found between the direction of work of some organizations and the official and non-official activities of civil servants. In general, the potential for establishing interaction between officials and the local community in the process of creating non-political organizations was noted
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