2,348 research outputs found
Analytical device model for graphene bilayer field-effect transistors using weak nonlocality approximation
We develop an analytical device model for graphene bilayer field-effect
transistors (GBL-FETs) with the back and top gates. The model is based on the
Boltzmann equation for the electron transport and the Poisson equation in the
weak nonlocality approximation for the potential in the GBL-FET channel. The
potential distributions in the GBL-FET channel are found analytically. The
source-drain current in GBL-FETs and their transconductance are expressed in
terms of the geometrical parameters and applied voltages by analytical formulas
in the most important limiting cases. These formulas explicitly account for the
short-gate effect and the effect of drain-induced barrier lowering. The
parameters characterizing the strength of these effects are derived. It is
shown that the GBL-FET transconductance exhibits a pronounced maximum as a
function of the top-gate voltage swing. The interplay of the short-gate effect
and the electron collisions results in a nonmonotonic dependence of the
transconductance on the top-gate length.Comment: 12 pages, 7 figure
Experimental grounding of the efficiency of the use of elastic operating elements in the devices for pre-sowing seed treatments
The article is devoted to the experimental studies of the effect of elastic operating elements of a mixer-dresser on seeds. Conducted experimental studies have shown the effectiveness of using the elastic operating elements for pre-sowing seed treatments. The proposed device is intended for the intensification of the process of mixing and dressing, excluding the traumatizing of seeds, and the harmful effect of protectant preparations on maintenance workers, while simplifying and reducing the cost of construction without additional power inputs. Experimental studies have confirmed the hypothesis, that the use ofshells, made of elastic materials,in the function of mixing devices, significantly reduces the time of preparation of homogeneous mixtures, due to the ability to accumulate the potential energy and to transfer it to the granular material,in the form of kinetic energy of mixed particles motion. Based on the performed researches, 3D model of the device for pre-sowing seed treatments has been developed. Hybrid elastic mixer-dressers can be used in agricultural enterprises, dealing with the issues of obtaining multicomponent granular mixtures and seed dressing.Web of Science97S74273
Factorization effects in a model of unstable particles
The effects of factorization are considered within the framework of the model
of unstable particles with a smeared mass. It is shown that two-particle cross
section and three-particle decay width can be described by the universal
factorized formulae for an unstable particles of an arbitrary spin in an
intermediate state. The exact factorization is caused by the specific structure
of the model unstable-particle propagators. This result is generalized to
complicated scattering and decay-chain processes with unstable particles in
intermediate states. We analyze applicability of the method and evaluate its
accuracy.Comment: 13 pages, 7 figure
Fuzzy interpretation for temporal-difference learning in anomaly detection problems
Nowadays, information control systems based on databases develop dynamically worldwide. These systems are extensively implemented
into dispatching control systems for railways, intrusion detection systems for computer security and other domains centered on big data
analysis. Here, one of the main tasks is the detection and prediction of temporal anomalies, which could be a signal leading to significant (and often critical) actionable information. This paper proposes the new anomaly prevent detection technique, which allows for determining the predictive temporal structures. Presented approach is based on a hybridization of stochastic Markov reward model by using fuzzy production rules, which allow to correct Markov information based on expert knowledge about the process dynamics as well as Markov’s intuition about the probable anomaly occurring. The paper provides experiments showing the efficacy of detection and prediction. In addition, the analogy between new framework and temporal-difference learning for sequence anomaly detection is graphically illustrated.Web of Science64363262
Modifications of gravity via differential transformations of field variables
We discuss field theories appearing as a result of applying field
transformations with derivatives (differential field transformations, DFT) to a
known theory. We begin with some simple examples of DFTs to see the basic
properties of the procedure. In this process the dynamics of the theory might
either change or conserve. After that we concentrate on the theories of gravity
which appear as a result of various DFT applied to general relativity, namely
the mimetic gravity and Regge-Teitelboim embedding theory. We review main
results related to the extension of dynamics in these theories, as well as the
possibility to write down the action of a theory after DFT as the action of the
original theory before DFT plus an additional term. Such a term usually
contains some constraints with Lagrange multipliers and can be interpreted as
an action of additional matter, which might be of use in cosmological
applications, e.g. for the explanation of the effects of dark matter.Comment: 18 page
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