scholarly journals Equilibrium Stochastic Delay Processes

Author(s):  
Viktor Holubec ◽  
Artem Ryabov ◽  
Sarah A. M. Loos ◽  
Klaus Kroy

Abstract Stochastic processes with temporal delay play an important role in science and engineering whenever finite speeds of signal transmission and processing occur. However, an exact mathematical analysis of their dynamics and thermodynamics is available for linear models only. We introduce a class of stochastic delay processes with nonlinear time-local forces and linear time-delayed forces that obey fluctuation theorems and converge to a Boltzmann equilibrium at long times. From the point of view of control theory, such ``equilibrium stochastic delay processes'' are stable and energetically passive, by construction. Computationally, they provide diverse exact constraints on general nonlinear stochastic delay problems and can, in various situations, serve as a starting point for their perturbative analysis. Physically, they admit an interpretation in terms of an underdamped Brownian particle that is either subjected to a time-local force in a non-Markovian thermal bath or to a delayed feedback force in a Markovian thermal bath. We illustrate these properties numerically for a setup familiar from feedback cooling and point out experimental implications.

Trictrac ◽  
2016 ◽  
Vol 9 ◽  
Author(s):  
Liliana Danciu ◽  
Petru Adrian Danciu

The axes of the creation and birth of the imaginary as a mythical language. Our research follows the relationships of the concepts that are taking into account creation on the double axis of verticality and horizontality. We highlight those symbolic elements which would later constitute the mythical language about the sacred space-temporality. Inside this space-temporality a rich spectrum of mythical images develops; images capable of explaining the relationships of the creation plans. Without a religious perception of the temporality, the conceptualization of the axis would remain a philosophical approach. Through our point of view, the two are born simultaneously. Thanks to them, creation can be imagined. The first “frozen” formula of the mystical human spirit can be thought, brought to a palpable reality, expressed in an oral and then a written form. Studied together, temporality (sacred or not) and space are permanently imagined together. For example, a loss of mundane temporality in the secret ecstasy that offers to the soul an ascending direction does not mean getting out of universal temporality, but of its mundane section. In the sacred space the soul relates to time. Even the gods are submitted by the sacred, Aeon sometimes being synonymous to destiny. The universal creator seems to evade every touch, but not consistently, only when he avoids the descent into its created worlds. In sacredness, time and space seem or become confused, both expressing the same reality, by the immediate swing from thinking to deed. The mythical imagery conceives the displacement in the primary space-temporality by the spoken word. So, for something to appear and live, the spoken word is required. Even the divine dream appears as a pre-word of a creator’s thought. The thought follows the spoken word, the spoken word follows the gestures which finally indicate the meanings of the creative act, controlling the rhythm of the creation days. These three will later be adapted through imitation in rite. We are now situated at the limit of the physical world, a real challenge for the mythical imagery. The general feature of the mythical expression on the creation of the material world is the state of the divinity’s exhaustion, most often conceptualized by sacrifice or divine fatigue. The world geography identifies with the anatomy of a self-gutted god. Practically, material creation is most likely the complete revelation of God’s body autopsy. As each body decomposes, everything in it is an illusion. An axial approach of the phenomenon exists in all religious systems. The created element’s origin is exterior, with or without a pre-existing matter, by a god’s sacrifice or only because it has to be that way. This is the starting point of the discussion on the symbolism of axiality as a reason for the constitution of the language of creation, capable of retelling the imaginary construction of myth in an oral and then written form.


2012 ◽  
pp. 66-80
Author(s):  
Michał Mrozowicki

Michel Butor, born in 1926, one of the leaders of the French New Novel movement, has written only four novels between 1954 and 1960. The most famous of them is La Modification (Second thoughts), published in 1957. The author of the paper analyzes two other Butor’s novels: L’Emploi du temps (Passing time) – 1956, and Degrés (Degrees) – 1960. The theme of absence is crucial in both of them. In the former, the novel, presented as the diary of Jacques Revel, a young Frenchman spending a year in Bleston (a fictitious English city vaguely similar to Manchester), describes the narrator’s struggle to survive in a double – spatial and temporal – labyrinth. The first of them, formed by Bleston’s streets, squares and parks, is symbolized by the City plan. During his one year sojourn in the city, using its plan, Revel learns patiently how to move in its different districts, and in its strange labyrinth – strange because devoid any centre – that at the end stops annoying him. The other, the temporal one, symbolized by the diary itself, the labyrinth of the human memory, discovered by the narrator rather lately, somewhere in the middle of the year passed in Bleston, becomes, by contrast, more and more dense and complex, which is reflected by an increasinly complex narration used to describe the past. However, at the moment Revel is leaving the city, he is still unable to recall and to describe the events of the 29th of February 1952. This gap, this absence, symbolizes his defeat as the narrator, and, in the same time, the human memory’s limits. In Degrees temporal and spatial structures are also very important. This time round, however, the problems of the narration itself, become predominant. Considered from this point of view, the novel announces Gerard Genette’s work Narrative Discourse and his theoretical discussion of two narratological categories: narrative voice and narrative mode. Having transgressed his narrative competences, Pierre Vernier, the narrator of the first and the second parts of the novel, who, taking as a starting point, a complete account of one hour at school, tries to describe the whole world and various aspects of the human civilization for the benefit of his nephew, Pierre Eller, must fail and disappear, as the narrator, from the third part, which is narrated by another narrator, less audacious and more credible.


2018 ◽  
Vol 28 (6) ◽  
pp. 1993-2005
Author(s):  
Shemsije Demiri ◽  
Rudina Kaja

This paper deals with the right to property in general terms from its source in Roman law, which is the starting point for all subsequent legal systems. As a result of this, the acquisition of property rights is handled from the historical point of view, with the inclusion of various local and international literature and studies, as well as the legal aspect devoted to the respective civil codes of the states cited in the paper.Due to such socio-economic developments, state ownership and its ownership function have changed. The state function as owner of property also changed in Macedonia's property law.The new constitutional sequence of the Republic of Macedonia since 1991 became privately owned as a dominant form of ownership, however, state ownership also exists.This process of transforming social property into state or private (dissolves), in Macedonia starts from Yugoslavia through privatization, return and denationalization measures, on which basis laws on privatization have been adopted. Because of this, there will be particularly intensive negotiations regaring the remaining state assets.


2020 ◽  
Vol 27 (5) ◽  
pp. 400-410
Author(s):  
Valentina De Luca ◽  
Luigi Mandrich

: Enzymes are among the most studied biological molecules because better understanding enzymes structure and activity will shed more light on their biological processes and regulation; from a biotechnological point of view there are many examples of enzymes used with the aim to obtain new products and/or to make industrial processes less invasive towards the environment. Enzymes are known for their high specificity in the recognition of a substrate but considering the particular features of an increasing number of enzymes this is not completely true, in fact, many enzymes are active on different substrates: this ability is called enzyme promiscuity. Usually, promiscuous activities have significantly lower kinetic parameters than to that of primary activity, but they have a crucial role in gene evolution. It is accepted that gene duplication followed by sequence divergence is considered a key evolutionary mechanism to generate new enzyme functions. In this way, promiscuous activities are the starting point to increase a secondary activity in the main activity and then get a new enzyme. The primary activity can be lost or reduced to a promiscuous activity. In this review we describe the differences between substrate and enzyme promiscuity, and its rule in gene evolution. From a practical point of view the knowledge of promiscuity can facilitate the in vitro progress of proteins engineering, both for biomedical and industrial applications. In particular, we report cases regarding esterases, phosphotriesterases and cytochrome P450.


2020 ◽  
Vol 16 (6) ◽  
pp. 784-795
Author(s):  
Krisnna M.A. Alves ◽  
Fábio José Bonfim Cardoso ◽  
Kathia M. Honorio ◽  
Fábio A. de Molfetta

Background:: Leishmaniosis is a neglected tropical disease and glyceraldehyde 3- phosphate dehydrogenase (GAPDH) is a key enzyme in the design of new drugs to fight this disease. Objective:: The present study aimed to evaluate potential inhibitors of GAPDH enzyme found in Leishmania mexicana (L. mexicana). Methods: A search for novel antileishmanial molecules was carried out based on similarities from the pharmacophoric point of view related to the binding site of the crystallographic enzyme using the ZINCPharmer server. The molecules selected in this screening were subjected to molecular docking and molecular dynamics simulations. Results:: Consensual analysis of the docking energy values was performed, resulting in the selection of ten compounds. These ligand-receptor complexes were visually inspected in order to analyze the main interactions and subjected to toxicophoric evaluation, culminating in the selection of three compounds, which were subsequently submitted to molecular dynamics simulations. The docking results showed that the selected compounds interacted with GAPDH from L. mexicana, especially by hydrogen bonds with Cys166, Arg249, His194, Thr167, and Thr226. From the results obtained from molecular dynamics, it was observed that one of the loop regions, corresponding to the residues 195-222, can be related to the fitting of the substrate at the binding site, assisting in the positioning and the molecular recognition via residues responsible for the catalytic activity. Conclusion:: he use of molecular modeling techniques enabled the identification of promising compounds as inhibitors of the GAPDH enzyme from L. mexicana, and the results obtained here can serve as a starting point to design new and more effective compounds than those currently available.


1967 ◽  
Vol 113 (501) ◽  
pp. 813-822 ◽  
Author(s):  
Örnulv Ödegård

My choice of Kraepelin as a point of departure for this lecture has definite reasons. If one wants to stay within the field of clinical psychiatry (as opposed to psychiatric history), that is as far back as one can reasonably go. By this no slight is intended upon the pre-Kraepelinian psychiatrists. For our topic Henry Maudsley would indeed have been a most appropriate starting point, and by no means for reasons of courtesy. His general point of view is admirably sound as a basis for the scientific study of prognosis in psychiatry. I quote: “There is no accident in madness. Causality, not casualty, governs its appearance in the universe, and it is very far from being a good and sufficient practice simply to mark its phenomena and straightway to pass on as if they belonged not to an order but to a disorder of events that called for no explanation.” On the special problem of prognosis he shows his clinical acumen by stating that the outlook is poor when the course of illness is insidious, but this only means that these cases develop their psychoses on the basis of mental deviations which go very far back in the patient's life, so that in fact they are generally in a chronic stage at the time of their first admission to hospital. Here he actually corrects a mistake which is still quite often made. He shows his dynamic attitude when he says that prognosis is to a large extent modified by external conditions, in particular by the attitude of friends and relatives. Maudsley's dynamic reasoning was limited by the narrow framework of the degeneration hypothesis of those days. He had a sceptical attitude towards classification, which he regarded as artificial and dangerously pseudo-exact. His own classification was deliberately provisional, with very wide groups. He held that a description of various sub-forms of chronic insanity was useless, as it would mean nothing but a tiresome enumeration of unconnected details.


2021 ◽  
Author(s):  
Lilibeth Chiquinquira Perdomo ◽  
Carlos Alvarez ◽  
Maria Edith Gracia ◽  
Guillermo Danilo Salomone ◽  
Gilberto Ventuirini ◽  
...  

Abstract As other companies registered in the US stock market, the company reports oil and gas reserves, in compliance with the definitions of the Securities and Exchange Commission (SEC). In addition, it complies internally with the guidelines established by the Petroleum Resources Management System to certify its resources. The PRMS focuses on supporting consistent evaluation of oil resources based on technically sound industry practices, providing fundamental principles for the assessment and classification of oil reserves and resources, but does not provide specific guidance for the classification and categorization of quantities associated with IOR projects. Recently, the company has implemented EOR pilot projects, and their results seem to show commerciality for future development or expansion to new areas, displaying multiple opportunities and proposals to incorporate reserves and resources. So far, the pilot projects and their expansions have been addressed only from the point of view of incremental projects, as an improvement over the previous secondary recovery. The company does not have sufficient track record in booking reserves or resources from EOR projects, their quantities have been incorporated following bibliographic references and results of EOR projects with proven commerciality around the world. For this reason, the need arose to have a tool that provides the company with methodological criteria to evaluate the resources and reserves inherent in this type of project, that incorporate the "best practices" of the industry and that respect the guidelines and definitions of PRMS for incremental projects. That was how, the need to meet this challenging goal led company to develop its "EOR Resources and Reserves Assessment Guide" with the advice of a renowned consulting company. Although the Guide is not intended to be a review of the large body of existing IOR literature, it contains several useful references that serve as a starting point for understanding the IOR project for assessment process of resources and reserves. This document shows the process of development and implementation of the EOR guide, complementing the existing guides within the corporation and providing the company with a positive result within the internal processes of Audit, reserves and resources for this type of projects.


Author(s):  
Валерий Иванович Хабаров

Предложена схема формализации задач активной идентификации объекта с использованием аппарата теории моделей - современного раздела математической логики. Теория моделей позволяет погрузить предмет “планирование и анализ эксперимента” в контекст семантического анализа. Семантический анализ понимается как установление соответствия между миром и его формальным представлением. С этой точки зрения представления об исследуемом объекте выражаются в некоторой прикладной теории. Предложен вывод модели для данной теории как процесс интерпретации, в котором ключевая роль отводится “экспериментатору”. Полученные результаты могут быть использованы при проектировании архитектур интеллектуальных систем для экспериментальных исследований, для построения онтологии эксперимента, создания баз знаний Purpose. The purpose of this work is to formalize the tasks of active object identification based on the apparatus of model theory - a modern section of mathematical logic. Model theory allows putting the subject “planning and analysis of an experiment” in the context of semantic analysis. Semantic analysis is understood as establishing a correspondence between the world and its formal representation. From this point of view, the concept of the object under study is expressed in some applied theory, which allows applying formal methods of model theory to it. Methods. It is assumed that the model is derived for this theory as an interpretation process, in which the key role is assigned to the experimenter. As a research method, it is proposed to use commutative diagrams that reflect the process of interpretation and extension of communication diagrams for the so-called equipped theories of planning and analysis of experiments. Results. The properties of the proposed models are proved and examples for planning a regression experiment are presented as an illustration. It is proved that for linear models it is possible to construct a finitely axiomatization capable theory. Findings, originality. The obtained results can be used in the design of architectures for an intelligent system in experimental research, building an experiment ontology and creation of knowledge bases. These studies will allow using logical programming to implement images of the presented commutative diagrams for equipped theories as applied systems for planning and interpreting the experiment


2013 ◽  
Vol 30 (6) ◽  
pp. 20-31 ◽  
Author(s):  
Peter Balazs ◽  
Monika Doerfler ◽  
Matthieu Kowalski ◽  
Bruno Torresani

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