scholarly journals Completeness by Modal Definitions. Application to the Epistemic Logic With Hypotheses

2020 ◽  
Vol 23 (65) ◽  
pp. 1-18
Author(s):  
Levan Uridia ◽  
Dirk Walther
Keyword(s):  
Epistemic Logic ◽  
Common Knowledge ◽  
Conditional Logic ◽  
Modal Operator ◽  
Distributed Knowledge ◽  
Topological Structures ◽  
The Common ◽  
Reasoning About Knowledge

We investigate the variant of epistemic logic S5 for reasoning about knowledge under hypotheses. The logic is equipped with a modal operator of necessity that can be parameterized with a hypothesis representing background assumptions. The modal operator can be described as relative necessity and the resulting logic turns out to be a variant of Chellas’ Conditional Logic. We present an axiomatization of the logic and its extension with the common knowledge operator and distributed knowledge operator. We show that the logics are decidable, complete w.r.t. Kripke as well as topological structures. The topological completeness results are obtained by utilizing the Alexandroff connection between preorders and Alexandroff spaces.

scholarly journals Common Knowledge in Epistemic Logic With Hypotheses

10.29007/glrl ◽  
2019 ◽  
Author(s):  
Levan Uridia ◽  
Dirk Walther
Keyword(s):  
Epistemic Logic ◽  
Common Knowledge ◽  
Modal Operator ◽  
The Common ◽  
Reasoning About Knowledge

We recall the epistemic logic S5r for reasoning about knowledge under hypotheses and we investigate the extension of the logic with an operator for common knowledge. The logic S5r is equipped with a modal operator of necessity that can be parameterized with hypotheses representing background assumptions while the extension with the common knowledge operator enables us to describe and reason about common knowledge among agents with possibly different background assumptions. We present an axiomatization of the logic and prove Kripke completeness and decidability results.

scholarly journals Client-Server Approach for Managing Visual Attention, Integrated in a Cognitive Architecture for a Social Robot

2021 ◽  
Vol 15 ◽  
Author(s):  
Francisco Martín ◽  
Jonatan Ginés ◽  
Francisco J. Rodríguez-Lera ◽  
Angel M. Guerrero-Higueras ◽  
Vicente Matellán Olivera
Keyword(s):  
Visual Attention ◽  
Knowledge Representation ◽  
Common Knowledge ◽  
Cognitive Architecture ◽  
Social Robot ◽  
Knowledge Graph ◽  
Distributed Knowledge ◽  
Client Server ◽  
The Core ◽  
The Common

This paper proposes a novel system for managing visual attention in social robots. This system is based on a client/server approach that allows integration with a cognitive architecture controlling the robot. The core of this architecture is a distributed knowledge graph, in which the perceptual needs are expressed by the presence of arcs to stimuli that need to be perceived. The attention server sends motion commands to the actuators of the robot, while the attention clients send requests through the common knowledge representation. The common knowledge graph is shared by all levels of the architecture. This system has been implemented on ROS and tested on a social robot to verify the validity of the approach and was used to solve the tests proposed in RoboCup @ Home and SciROc robotic competitions. The tests have been used to quantitatively compare the proposal to traditional visual attention mechanisms.

scholarly journals Common Knowledge

1992 ◽  
Vol 6 (4) ◽  
pp. 53-82 ◽  
Author(s):  
John Geanakoplos
Keyword(s):  
Common Knowledge ◽  
Economic Behavior ◽  
Infinite Chain ◽  
The Common ◽  
Reasoning About Knowledge ◽  
The Way

An event is common knowledge among a group of agents if each one knows it, if each one knows that the others know it, if each one knows that each one knows that the others know it, and so on. Thus, common knowledge is the limit of a potentially infinite chain of reasoning about knowledge. The purpose of this paper is to survey some of the implications for economic behavior of the hypotheses that events are common knowledge, that actions are common knowledge, that optimization is common knowledge, and that rationality is common knowledge. It will begin with several puzzles that illustrate the strength of the common knowledge hypothesis. It will then study how common knowledge can illuminate many problems in economics. In general, the discussion will show that a talent for interactive thinking is advantageous, but if everyone can think interactively and deeply all the way to common knowledge, then sometimes puzzling consequences may result.

scholarly journals Small Undecidable Problems in Epistemic Planning

2018 ◽  
Author(s):  
Sébastien Lê Cong ◽  
Sophie Pinchinat ◽  
François Schwarzentruber
Keyword(s):  
Cellular Automata ◽  
Epistemic Logic ◽  
Common Knowledge ◽  
Dynamic Epistemic Logic ◽  
Planning Problem ◽  
Reachability Problem ◽  
Public Action ◽  
Automatic Structure ◽  
The Common ◽  
Initial Knowledge

Epistemic planning extends classical planning with knowledge and is based on dynamic epistemic logic (DEL). The epistemic planning problem is undecidable in general. We exhibit a small undecidable subclass of epistemic planning over 2-agent S5 models with a fixed repertoire of one action, 6 propositions and a fixed goal. We furthermore consider a variant of the epistemic planning problem where the initial knowledge state is an automatic structure, hence possibly infinite. In that case, we show the epistemic planning problem with 1 public action and 2 propositions to be undecidable, while it is known to be decidable  with public actions over finite models. Our results are obtained by reducing the reachability problem over small universal cellular automata. While our reductions yield a goal formula that displays the common knowledge operator, we show, for each of our considered epistemic problems, a reduction into an epistemic planning problem for a common-knowledge-operator-free goal formula by using 2 additional actions.

scholarly journals Common Knowledge in an Epistemic Logic with Hypotheses

10.29007/43wj ◽  
2020 ◽  
Author(s):  
Levan Uridia ◽  
Dirk Walther
Keyword(s):  
Epistemic Logic ◽  
Common Knowledge ◽  
Background Knowledge ◽  
Knowledge Extension ◽  
Reasoning About Knowledge

We extend epistemic logic S5r for reasoning about knowledge under hypotheses with distributive knowledge operator. This extension gives possibility to express distributive knowledge of agents with different background assumptions. The logic is important in com- puter science since it models agents behavior which already have some equipped knowledge. Extension with distributive knowledge shows to be extremely interesting since knowledge of an arbitrary agent whose epistemic capacity corresponds to any system between S4 and S5 under some restrictions can be modeled as distributive knowledge of agents with cer- tain background knowledge. We present an axiomatization of the logic and prove Kripke completeness and decidability results.

scholarly journals Learning What Others Know

10.29007/plm4 ◽  
2020 ◽  
Author(s):  
Alexandru Baltag ◽  
Sonja Smets
Keyword(s):  
Information Sharing ◽  
Epistemic Logic ◽  
Common Knowledge ◽  
The Other ◽  
Distributed Knowledge ◽  
Multi Agent ◽  
Information Database

We propose a number of powerful dynamic-epistemic logics for multi-agent information sharing and acts of publicly or privately accessing other agents’ information databases. The static base of our logics is obtained by adding to standard epistemic logic comparative epistemic assertions for groups or individuals, as well as a common distributed knowledge operator (that combines features of both common knowledge and distributed knowledge). On the dynamic side, we introduce actions by which epistemic superiority can be acquired: “sharing all one knows” (by e.g. giving access to one’s information database to all or some of the other agents), as well as more complex informational events, such as hacking. We completely axiomatize several such logics and prove their decidability.

El patriacado y la estructura social de la vida cotidiana

1970 ◽  
Author(s):  
Marta Postigo Asenjo
Keyword(s):  
Labor Market ◽  
Public Sphere ◽  
Civic Education ◽  
Common Knowledge ◽  
Judicial System ◽  
The Public ◽  
El Sistema ◽  
The Common ◽  
The Public Sphere ◽  
Ways Of Life

RESUMENEl sistema patriarcal no afecta exclusivamente al poder político y judicial, sino que afecta a la estructura interna de la sociedad, la identidad y las formas de vida de los individuos que en ella viven. Para comprender mejor como condiciona el sistema patriarcal las formas de vida y la visión que tienen los individuos de la realidad social, hemos de analizar el modo en que se extiende al orden institucional y lo determina mediante "tipificaciones" de hechos y de personas y mediante roles concretos, esteoreotipaciones sexiuales que obstaculizan el acceso a la esfera pública de la mujer, así como su reinserción en el mercado laboral, en suma, todo aquello que afecta al conocimiento común que comparten los miembros de una comunidad. El cambio hacia una mayor igualdad y una real democracia paritaria y compartida no es posible sin una paulatina educación y concienciación de la sociedad en su conjunto.PALABRAS CLAVEPATRIARCADO-TIPIFICACIÓN SOCIAL-IGUALDAD DE GÉNEROABSTRACTPatriarchalism is not only present in politics and the judicial system. It also affects the internal structure of society, above all the life and identitý of individuals. To understand better how it conditions their ways of life and the vision the individuals have of social reality, we should study how patriarchalism r3eaches the system of institutions and how this becomes determined by "typifications" of facts and people, and by certain roles or sexual stereotypes that hinder the access of women both to the public sphere and to tha labor market. It sum, everything that concerns the common knowledge that the members of a community share. The move towards more equality and towards a more egalitarian democracy heavily depends on the spread of civic education to the entire society.KEYWORDSPATRIARCHALISM-SOCIAL TYPIFICATION-GENDER EQUALITY

The Creation of a Multi-Link Load Balancing Mechanism for Planetary Gearing: Part 2 — Optimum Mechanism Selection and Dimension Determination

1992 ◽  
Author(s):  
Zhang Hong ◽  
Wei-qing Cao ◽  
Ting Li Yang ◽  
Jin Kui Chu
Keyword(s):  
Load Balancing ◽  
Arbitrary Number ◽  
Uniform Load ◽  
Topological Structures ◽  
Optimum Load ◽  
New Type ◽  
The Common ◽  
The Creation ◽  
Set Up

Abstract This paper is the second of a series of two papers which designed a new type of load balancing mechanisms for planetary gearings with arbitrary number of planets. In this paper the common expression of the non-uniform load share factor was deduced, and a function parameter:force-arm factor and their solution was given. That makes it possible that the dimensions and the ability of load equilibrium of Multi-Link Load Balancing Mechanisms can be determined. The criteria of optimum load balancing Mechanisms selection were set up with consider of the effects of turning pair clearances, and optimum mechanisms were selected among the 15 candidates obtained in Part 1. Finally, it was demonstrated that the optimum multi-link load balancing mechanisms for arbitrary number of planets had the similar topological structures and same function and performence of load equilibrium.

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