scholarly journals Dynamical emergence of Markovianity in local time scheme

Author(s):  
J. Jeknić-Dugić ◽  
M. Arsenijević ◽  
M. Dugić

Recently we pointed out the so-called local time scheme as a novel approach to quantum foundations that solves the preferred pointer-basis problem. In this paper, we introduce and analyse in depth a rather non-standard dynamical map that is imposed by the scheme. On the one hand, the map does not allow for introducing a properly defined generator of the evolution nor does it represent a quantum channel. On the other hand, the map is linear, positive, trace preserving and unital as well as completely positive, but is not divisible and therefore non-Markovian. Nevertheless, we provide quantitative criteria for dynamical emergence of time-coarse-grained Markovianity, for exact dynamics of an open system, as well as for operationally defined approximation of a closed or open many-particle system. A closed system never reaches a steady state, whereas an open system may reach a unique steady state given by the Lüders–von Neumann formula; where the smaller the open system, the faster a steady state is attained. These generic findings extend the standard open quantum systems theory and substantially tackle certain cosmological issues.

2013 ◽  
Vol 385-386 ◽  
pp. 635-639
Author(s):  
Li Sen

Based on the diffraction theory of the one-dimensional gratings at oblique incidence, by introducing the laser autocollimation system, a novel approach of dynamically measuring small angles with three degrees of freedom is proposed. By matrix transform, a mathematical model is established to describe the changes of small 3D angles as a function of the variation of the image position of the diffraction spot, and the solution of this model is demonstrated. A prototype machine has been made to verify the practicability of the measuring method proposed. Analysis of the measuring range and resolution of the system shows that within the range of ±1.6 degrees.


Author(s):  
J. Jeknić-Dugić ◽  
M. Arsenijević ◽  
M. Dugić

There is a solution to the problem of asymptotic completeness in many-body scattering theory that offers a specific view of the quantum unitary dynamics which allows for the straightforward introduction of local time for every, at least approximately closed, many-particle system. In this approach, time appears as a hidden classical parameter of the unitary dynamics of a many-particle system. We show that a closed many-particle system can exhibit behaviour that is characteristic for open quantum systems and there is no need for the ‘state collapse’ or environmental influence. On the other hand, closed few-particle systems bear high quantum coherence. This local-time scheme encompasses concepts including ‘emergent time’, ‘relational time’ as well as the ‘hybrid system’ models with possibly induced gravitational uncertainty of time.


2020 ◽  
Vol 51 (3) ◽  
pp. 544-560 ◽  
Author(s):  
Kimberly A. Murphy ◽  
Emily A. Diehm

Purpose Morphological interventions promote gains in morphological knowledge and in other oral and written language skills (e.g., phonological awareness, vocabulary, reading, and spelling), yet we have a limited understanding of critical intervention features. In this clinical focus article, we describe a relatively novel approach to teaching morphology that considers its role as the key organizing principle of English orthography. We also present a clinical example of such an intervention delivered during a summer camp at a university speech and hearing clinic. Method Graduate speech-language pathology students provided a 6-week morphology-focused orthographic intervention to children in first through fourth grade ( n = 10) who demonstrated word-level reading and spelling difficulties. The intervention focused children's attention on morphological families, teaching how morphology is interrelated with phonology and etymology in English orthography. Results Comparing pre- and posttest scores, children demonstrated improvement in reading and/or spelling abilities, with the largest gains observed in spelling affixes within polymorphemic words. Children and their caregivers reacted positively to the intervention. Therefore, data from the camp offer preliminary support for teaching morphology within the context of written words, and the intervention appears to be a feasible approach for simultaneously increasing morphological knowledge, reading, and spelling. Conclusion Children with word-level reading and spelling difficulties may benefit from a morphology-focused orthographic intervention, such as the one described here. Research on the approach is warranted, and clinicians are encouraged to explore its possible effectiveness in their practice. Supplemental Material https://doi.org/10.23641/asha.12290687


1985 ◽  
Vol 53 (01) ◽  
pp. 122-125 ◽  
Author(s):  
B Åstedt ◽  
Ingegerd Lecander ◽  
T Brodin ◽  
A Lundblad ◽  
Karin Löw

SummaryA monoclonal antibody of IgG2a-type was obtained against a specific fast acting plasminogen activator inhibitor found in placenta. The placental inhibitor was purified by affinity chromatography using the monoclonal antibody and additionally in a FPLC-system. A strong complex formation was found between the inhibitor and urokinase and also with the two-chain form of plasminogen activator of the tissue-type. A weaker complex was found between the placental inhibitor and the one- chain form of the tissue-type activator.


2018 ◽  
Author(s):  
Steve Wang ◽  
Jim McGinn ◽  
Peter Tvarozek ◽  
Amir Weiss

Abstract Secondary electron detector (SED) plays a vital role in a focused ion beam (FIB) system. A successful circuit edit requires a good effective detector. Novel approach is presented in this paper to improve the performance of such a detector, making circuit altering for the most advanced integrated circuit (IC) possible.


Author(s):  
J Ph Guillet ◽  
E Pilon ◽  
Y Shimizu ◽  
M S Zidi

Abstract This article is the first of a series of three presenting an alternative method of computing the one-loop scalar integrals. This novel method enjoys a couple of interesting features as compared with the method closely following ’t Hooft and Veltman adopted previously. It directly proceeds in terms of the quantities driving algebraic reduction methods. It applies to the three-point functions and, in a similar way, to the four-point functions. It also extends to complex masses without much complication. Lastly, it extends to kinematics more general than that of the physical, e.g., collider processes relevant at one loop. This last feature may be useful when considering the application of this method beyond one loop using generalized one-loop integrals as building blocks.


Author(s):  
Paola Sangiorgio ◽  
Alessandra Verardi ◽  
Salvatore Dimatteo ◽  
Anna Spagnoletta ◽  
Stefania Moliterni ◽  
...  

AbstractThe increase in the world population leads to rising demand and consumption of plastic raw materials; only a small percentage of plastics is recovered and recycled, increasing the quantity of waste released into the environment and losing its economic value. The plastics represent a great opportunity in the circular perspective of their reuse and recycling. Research is moving, on the one hand, to implement sustainable systems for plastic waste management and on the other to find new non-fossil-based plastics such as polyhydroxyalkanoates (PHAs). In this review, we focus our attention on Tenebrio molitor (TM) as a valuable solution for plastic biodegradation and biological recovery of new biopolymers (e.g. PHA) from plastic-producing microorganisms, exploiting its highly diversified gut microbiota. TM’s use for plastic pollution management is controversial. However, TM microbiota is recognised as a source of plastic-degrading microorganisms. TM-based plastic degradation is improved by co-feeding with food loss and waste as a dietary energy source, thus valorising these low-value substrates in a circular economy perspective. TM as a bioreactor is a valid alternative to traditional PHA recovery systems with the advantage of obtaining, in addition to highly pure PHA, protein biomass and rearing waste from which to produce fertilisers, chitin/chitosan, biochar and biodiesel. Finally, we describe the critical aspects of these TM-based approaches, mainly related to TM mass production, eventual food safety problems, possible release of microplastics and lack of dedicated legislation.


2021 ◽  
Vol 183 (1) ◽  
Author(s):  
Géraldine Haack ◽  
Alain Joye

AbstractThis paper is devoted to the analysis of Lindblad operators of Quantum Reset Models, describing the effective dynamics of tri-partite quantum systems subject to stochastic resets. We consider a chain of three independent subsystems, coupled by a Hamiltonian term. The two subsystems at each end of the chain are driven, independently from each other, by a reset Lindbladian, while the center system is driven by a Hamiltonian. Under generic assumptions on the coupling term, we prove the existence of a unique steady state for the perturbed reset Lindbladian, analytic in the coupling constant. We further analyze the large times dynamics of the corresponding CPTP Markov semigroup that describes the approach to the steady state. We illustrate these results with concrete examples corresponding to realistic open quantum systems.


2014 ◽  
Vol 14 (04) ◽  
pp. 1450009 ◽  
Author(s):  
Andrew Yee Tak Leung ◽  
Hong Xiang Yang ◽  
Ping Zhu

This paper is concerned with the steady state bifurcations of a harmonically excited two-member plane truss system. A two-degree-of-freedom Duffing system having nonlinear fractional derivatives is derived to govern the dynamic behaviors of the truss system. Viscoelastic properties are described by the fractional Kelvin–Voigt model based on the Caputo definition. The combined method of harmonic balance and polynomial homotopy continuation is adopted to obtain steady state solutions analytically. A parametric study is conducted with the help of amplitude-response curves. Despite its seeming simplicity, the mechanical system exhibits a wide variety of structural responses. The primary and sub-harmonic resonances and chaos are found in specific regions of system parameters. The dynamic snap-through phenomena are observed when the forcing amplitude exceeds some critical values. Moreover, it has been shown that, suppression of undesirable responses can be achieved via changing of viscosity of the system.


2002 ◽  
Vol 8 (2) ◽  
pp. 261-276 ◽  
Author(s):  
Xiaogang Feng ◽  
Zhihong Ye ◽  
Fred C. Lee ◽  
Dushan Borojevic

PEBB (power electronics building block) systems are typical nonlinear systems. Under the conventional but still popular linear control design, the system stability margin varies from one operating point to another. This paper introduces a novel approach to monitoring the DC bus stability margin of a PEBB system online. At the steady state of the system, a small-signal perturbation current î p is injected into the DC bus, and the load-side response current î L is measured. By checking the validation |î L ( jw)| < |î p ( jw)|, the system stability margin can be examined. Experiments on a 48 V DC DPS demonstrate the proposed measurement approach. An implementation approach is also proposed for an 800 V DC PEBB-based testbed system.


Sign in / Sign up

Export Citation Format

Share Document