A modified direct inverse Prandtl–Ishlinskii model based on two sets of operators for the piezoelectric actuator hysteresis compensation

Piezoelectric actuator (PEA) is widely applied in the field of micro/nano high precision positioning. However PEA has the phenomenon of hysteresis non-linearity between input voltage and output displacement, due to the natural property of piezoelectric materials. The PEA hysteresis can be compensated by hysteresis models, which makes the input voltage and output displacement more linearity. The research work on compensation of PEA hysteresis by using various hysteresis models has been being a hot topic. This paper presents a modified direct inverse rate-independent Prandtl–Ishlinskii (PI) (MDIPI) model for compensating the hysteresis of PEA. The proposed MDIPI model has two different sets of operators compared with classical PI (CPI) model having one set of operators. For the two sets operators in MDIPI model one is rate operators and the other is modified classical operators. By combining the two sets operators, the MDIPI model has the properties of the adaption and accuracy in hysteresis compensation. The MDIPI model can be used as feedforward controller to compensate different reference trajectories. Parameters of MDIPI model are calculated by matlab optimization tool box. The experiments of compensating the complex displacement trajectory and sinusoidal trajectory are validated on a platform of commercial PEA. The MDIPI model has achieved more accurate results than the Krasnosel’skii–Pokrovkii (KP), Preisach and CPI models. It is effective in improving the accuracy of PEA hysteresis compensation.

An Exponential Separation Between MA and AM Proofs of Proximity

Interactive proofs of proximity allow a sublinear-time verifier to check that a given input is close to the language, using a small amount of communication with a powerful (but untrusted) prover. In this work, we consider two natural minimally interactive variants of such proofs systems, in which the prover only sends a single message, referred to as the proof. The first variant, known as -proofs of Proximity (), is fully non-interactive, meaning that the proof is a function of the input only. The second variant, known as -proofs of Proximity (), allows the proof to additionally depend on the verifier's (entire) random string. The complexity of both s and s is the total number of bits that the verifier observes—namely, the sum of the proof length and query complexity. Our main result is an exponential separation between the power of s and s. Specifically, we exhibit an explicit and natural property $$\Pi$$ Π that admits an with complexity $$O(\log n)$$ O ( log n ) , whereas any for $$\Pi$$ Π has complexity $$\tilde{\Omega}(n^{1/4})$$ Ω ~ ( n 1 / 4 ) , where n denotes the length of the input in bits. Our lower bound also yields an alternate proof, which is more general and arguably much simpler, for a recent result of Fischer et al. (ITCS, 2014). Also, Aaronson (Quantum Information & Computation 2012) has shown a $$\Omega(n^{1/6})$$ Ω ( n 1 / 6 ) lower bound for the same property $$\Pi$$ Π .Lastly, we also consider the notion of oblivious proofs of proximity, in which the verifier's queries are oblivious to the proof. In this setting, we show that s can only be quadratically stronger than s. As an application of this result, we show an exponential separation between the power of public and private coin for oblivious interactive proofs of proximity.

Study of Von Neumann Abelian Regular Rings

This paper is concerned with the basic properties of a class of regular rings of some "classical" type. Abelian regular rings are, however, a more indirect concept, in that a nontrivial theorem is required to show that strongly regular rings are actually regular. For this reason, we view abelianness as the more natural property. We first collect a number of equivalent characterizations of abelian regular rings, before proving that "abelian regular" is equivalent to "strongly regular". GUB JOURNAL OF SCIENCE AND ENGINEERING, Vol 7, Dec 2020 P 14-20

Influence of Temperature and Rest Period on Damage Repair of Aged Asphalt

One important natural property of asphalt materials is the ability to self-repair damages. This property could extend service life of asphalt roads and help deter maintenance to some accountable time. This property is basically working on rejuvenating the aged bitumen when cracks appear. With this purpose, two types of asphalt mixtures were developed. Aged mixture and unaged mixture for the purpose of comparison between the results. The objective of this work is to investigate the effect of higher temperature in Iraq on enhancing the asphalt self-repair. Different rest periods were applied to give time to the bitumen to move and redistribute again while reversing the ageing effect. The major agent in that is the viscosity of asphalt, which is reduced by high temperature and allow the bitumen to move again and increase the wettability of asphalt. The ageing of samples was done in the laboratory according to specifications and the temperature was provided in field as the study focus on summer temperature of Iraq. It was found that applying only temperature on aged asphalt reduced the viscosity and increased the flow of bitumen, which is a highly promising finding at this stage and further investigations are recommended in the end of this study.

Laws, Exceptions and Dispositions

Can laws of nature be universal regularities and nevertheless have exceptions? Several answers to this question, in particular the thesis that there are no laws outside of fundamental physics, are examined and rejected. It is suggested that one can account for exceptions by conceiving of laws as strictly universal determination relations between (instances of) properties. When a natural property is instantiated, laws of nature give rise to other, typically dispositional properties. In exceptional situations, such properties manifest themselves either in an unusual way or not at all.

Image Enhancement Using Wavelet Based Image Fusion and Power Law Transform

One of the best branches of data fusion is Image Fusion and Power law transform is having its own importance in image enhancement. The future applications will be mainly based on image brightness and image sharpness. The enhanced images provide better information than the low-quality blur images. In this paper, we acquired a solitary image which introduces better execution under a few assessment criteria’s by combining wavelet transform with power law transformation for the images at around various locales. Wavelet transform is basically utilized as a result of its natural property that is, they are repetitive and move variation. It changes image into various scales. In power law transformation one must pick the example showing up in the transform capacity with the end goal that it doesn’t corrupt the nature of the image. The empirical results are better for proposed algorithm compare with state of art algorithms.

Two Crucial Experiments on the Nature of Light: Beyond the Bounds of Wave-Particle Duality

The wave-particle duality of light has been hanging over the clouds of science as an insuperable mystery. Debates have gone on for centuries as to which of the two aspects of light best represents the natural property of light. On the one hand, the particle theory of light camp made its own submissions a long time ago with many experimental demonstrations to confirm its position. On the other hand, the wave theory of light camp did organize or face some experiments to corroborate its own position. But then, a middle ground interpretation was shoveled-in by Niels Bohr during the second decade of the 20th Century. For him, the two aspects of light are complementary and Louis de Broglie popularized it, despite the halting beginnings of the complementarity Thesis. A double-slit experiment was, however, organized to show that light has these dual aspects. The central thesis of this paper is that though light exhibits these dual aspects, it is fundamentally a wave. The paper adopts the historiographical approach in navigating this lingering issue of the nature of light in the history of science.

Acetone Sensing Based on Transmittance of Hydroxyethyl Methacrylate-Liquid Crystal Materials

Poly hydroxyethyl methacrylate (p-HEMA) has a natural property that is very easy to absorb a liquid or solution and become a hydrogel when absorbing water. In this work, by combining p-HEMA material with a cholesteric liquid crystal (CLC), the material can absorb the solution and the optical properties of the liquid crystal will change depending on the solution it absorbs. The solution used in this work is acetone. During the absorption process the p-HEMA material expanded so that the orientation direction of liquid crystal molecular twist with a helical axis along can freely move and change. In this work, we observed the study of transmittance caused by thickness effect and the mixture concentration effect of the poly hydroxyethyl methacrylate liquid crystals (PHM-LC).

What Normativity Cannot Be

Here, I consider Derek Parfit’s Normativity Objection to naturalist realism, according to which normative-natural property or fact reductions are “conceptually excluded”. While a lot of philosophers inclined toward non-naturalism share this view or something close to it, plenty of philosophers remain unconvinced, and the literature offers little guidance to the perplexed. I suggest a way to improve the argument – indeed, I think it is the best and perhaps only plausible way to make good on the claim of conceptual exclusion. But the improved argument relies on the highly controversial claim that normative cognition is transparentin the following sense: normative concepts reveal the nature of the properties they aim to ascribe. This nature, the argument continues, is inconsistent with naturalist strictures.

On the use of near-neutral backward Lyapunov vectors to get reliable ensemble forecasts in coupled ocean-atmosphere systems

<p>The use of coupled Backward Lyapunov vectors (BLv) for ensemble forecast is demonstrated in a coupled ocean-atmosphere system of reduced order, the Modular Arbitrary Order Ocean-Atmosphere sytem (MAOOAM). It is found that the best set of BLvs to build a coupled ocean-atmosphere forecasting system are the ones associated with near-neutral or slightly negative Lyapunov exponents. This counter intuitive result is related to the fact that these sets display larger projections on the ocean variables than the others, leading to an appropriate spread for the ocean, and at the same time a rapid transfer of these errors toward the most unstable BLvs affecting predominantly the atmosphere is experienced. The latter dynamics is a natural property of any generic perturbation in nonlinear chaotic dynamical systems, allowing for a reliable spread with the atmosphere too. The implications of these results for operational ensemble forecasts in coupled ocean-atmosphere systems are discussed.  </p>