Search results for " Concept"
showing 10 items of 1144 documents
Gradation of Fuzzy Preconcept Lattices
2021
Noticing certain limitations of concept lattices in the fuzzy context, especially in view of their practical applications, in this paper, we propose a more general approach based on what we call graded fuzzy preconcept lattices. We believe that this approach is more adequate for dealing with fuzzy information then the one based on fuzzy concept lattices. We consider two possible gradation methods of fuzzy preconcept lattice—an inner one, called D-gradation and an outer one, called M-gradation, study their properties, and illustrate by a series of examples, in particular, of practical nature.
Electronic properties of graphene: A learning path for undergraduate students
2016
The purpose of this work is to present a learning path aimed at deepening student understanding of the fundamental concepts underlying the electronic properties of new materials, graphene in particular. To achieve this task, we propose a five-week long workshop where students may be introduced to fundamental concepts of advanced physics, rarely used in learning paths, such as the symmetry properties of the crystal lattice, the group theory , the features of the free electron wave functions and energy levels, the relativistic Dirac equation. Particular emphasis is given to the manner of introducing these concepts, since an essential knowledge of solid state physics, quantum physics and relat…
Consensus in Noncooperative Dynamic Games: a Multi-Retailer Inventory Application
2008
We focus on Nash equilibria and Pareto optimal Nash equilibria for a finite horizon noncooperative dynamic game with a special structure of the stage cost. We study the existence of these solutions by proving that the game is a potential game. For the single-stage version of the game, we characterize the aforementioned solutions and derive a consensus protocol that makes the players converge to the unique Pareto optimal Nash equilibrium. Such an equilibrium guarantees the interests of the players and is also social optimal in the set of Nash equilibria. For the multistage version of the game, we present an algorithm that converges to Nash equilibria, unfortunately, not necessarily Pareto op…
Noncooperative dynamic games for inventory applications: A consensus approach
2008
We focus on a finite horizon noncooperative dynamic game where the stage cost of a single player associated to a decision is a monotonically nonincreasing function of the total number of players making the same decision. For the single-stage version of the game, we characterize Nash equilibria and derive a consensus protocol that makes the players converge to the unique Pareto optimal Nash equilibrium. Such an equilibrium guarantees the interests of the players and is also social optimal in the set of Nash equilibria. For the multi-stage version of the game, we present an algorithm that converges to Nash equilibria, unfortunately not necessarily Pareto optimal. The algorithm returns a seque…
Introspection and equilibrium selection in 2 � 2 matrix games
1994
Game theory lacks an explanation of how players' beliefs are formed and why they are in equilibrium. This is the reason why it has failed to make significant advances with the problem of equilibrium selection even for quite siniple games, as 2x2 games with two strict Nash equilibria. Our paper models the introspection process by which the selected equilibrium is achieved in this class of games. Players begin their analysis with imprecise priors, obtained under weak restrictions formulated as Axioms. For a large class of reasoning dynamics we obtain as the solution the risk dominant Nash equilibrium.
Nonstationary flow surface theory for modeling the viscoplastic behaviors of soils
2016
Abstract This paper presents a three-dimensional elastic viscoplastic model that can describe the time-dependent behaviors of soft clays. The constitutive model is formulated based on the nonstationary flow surface theory and incorporates new developments, including (i) an improved definition of the nonstationary flow surface that is capable of capturing the stress–strain behaviors under different loading paths, (ii) a unique stress–strain—viscoplastic-strain-rate equation that is able to explicitly describe the nonstationary flow surface, and (iii) a final stable state concept that identifies the final equilibrium state at the end of creep and stress relaxation, which is also used to simpl…
Una storia italiana: Giorgio e Isabella
2018
Si tratta, qui, della storia di due italiani dalla “pelle scura” raccontata, per Giorgio Marincola, da Carlo Costa e Lorenzo Teodonio in Razza partigiana e, per la sorella Isabella, da Wu Ming 2 e Antar Mohamed in Timira. Romanzo meticcio. Le loro vicende, così come molti altri aspetti della nostra storia coloniale, neocoloniale e postcoloniale, sono riemerse dal buio nel quale erano state occultate solo nell’ultimo quindicennio, grazie alla riapertura degli archivi che ha permesso di ridiscutere molti degli aspetti che nelle pagine di Storia, così come in quelle letterarie, erano stati raccontati in altro modo. I due testi, che hanno inevitabilmente finito per incontrarsi e che potremmo in…
Paradoxes of postmodern tourists and innovation in tourism marketing
2018
Innovation challenges tourism experiences in a new digitalized era. The new scenario is showing some paradoxical changes that lead to new approaches for tourism production, distribution, and financing. This chapter focuses on innovation in marketing, involving market processes, new changes in tourist behavior and new approaches adopted by companies to face new trends. An emphasis is given to service innovation in tourism, with a special focus on companies, tourist destinations, and the digital environment. Likewise, the chapter examines a series of paradoxes of postmodern tourists and how companies develop new products and services to try to address them.
Governance forms drivers in bio-pharmaceutial inter-firm relationships
2012
Networking benefits are acknowledged by many studies in the industrial organization and strategic management fields; transaction cost theory agency and property right theory provide the economic foundations to the market-hierarchy dilemma; while Resource based-view (RBV), relational and evolutionary theories provide the strategic foundation of the inter-firm relationships. All this theoretical strands investigate reasons that push firms to formalize their relationship in different governance structures. The bio-pharmaceutical industry has the characteristics to offer to the potential partners both exploitation or exploration alliances benefits. In particular some elements play a “pivot” rol…
Introduction: Uncertain Biographies? A Focus on Migrants’ Life Courses
2018
This book focuses on the uncertainties revealed by migrants’ biographies whose shapes are less conventional or patterned, while their family, work, and educational careers are simultaneously more fragmented and intermingled. As Gardner (Age, Narrative and Migration: The Life Course and Life Histories of Bengali Elders in London. Oxford: Berg Publishers, 2002) contends, there is a more pressing need to address the meaning and shape of life course in migrants’ case. The chapters ask therefore: What challenges migrants and returnees face when trying to make sense of their life courses after years of experience in other countries with different age norms and cultural values? How can they reconc…