scholarly journals Revisiting the Foundations of Abstract Argumentation – Semantics Based on Weak Admissibility and Weak Defense

2020 ◽  
Vol 34 (03) ◽  
pp. 2742-2749
Author(s):  
Ringo Baumann ◽  
Gerhard Brewka ◽  
Markus Ulbricht
Keyword(s):  
Classical Case ◽  
Research Area ◽  
Major Research ◽  
Abstract Argumentation ◽  
New Concepts ◽  
Key Concepts ◽  
Problematic Issue ◽  
Rigorous Study ◽  
Grounded Semantics ◽  
Special Case

In his seminal 1995 paper, Dung paved the way for abstract argumentation, a by now major research area in knowledge representation. He pointed out that there is a problematic issue with self-defeating arguments underlying all traditional semantics. A self-defeat occurs if an argument attacks itself either directly or indirectly via an odd attack loop, unless the loop is broken up by some argument attacking the loop from outside. Motivated by the fact that such arguments represent self-contradictory or paradoxical arguments, he asked for reasonable semantics which overcome the problem that such arguments may indeed invalidate any argument they attack. This paper tackles this problem from scratch. More precisely, instead of continuing to use previous concepts defined by Dung we provide new foundations for abstract argumentation, so-called weak admissibility and weak defense. After showing that these key concepts are compatible as in the classical case we introduce new versions of the classical Dung-style semantics including complete, preferred and grounded semantics. We provide a rigorous study of these new concepts including interrelationships as well as the relations to their Dung-style counterparts. The newly introduced semantics overcome the issue with self-defeating arguments, and they are semantically insensitive to syntactic deletions of self-attacking arguments, a special case of self-defeat.

scholarly journals On the Maximal Number of Complete Extensions in Abstract Argumentation Frameworks

2021 ◽  
Author(s):  
Markus Ulbricht
Keyword(s):  
Expressive Power ◽  
Research Area ◽  
Formal Proof ◽  
Knowledge Representation And Reasoning ◽  
Intrinsic Properties ◽  
Lower And Upper Bounds ◽  
Major Research ◽  
Exact Bound ◽  
Abstract Argumentation ◽  
Points Of View

Abstract argumentation frameworks are by now a major research area in knowledge representation and reasoning. Various aspects of AFs have been extensively studied over the last 25 years. Contributing to understanding the expressive power of AFs, researchers found lower and upper bounds for the maximal number of extensions, that is, acceptable points of view, in AFs. One of the classical and most important concepts in AFs are so-called complete extensions. Surprisingly, the exact bound for the maximal number of complete extensions in an AF has not yet been formally established, although there is a reasonable conjecture tracing back at least to 2015. Recently the notion of modularization was introduced and it was shown that this concept plays a key role for the understanding of relations between semantics as well as intrinsic properties. In this paper, we will use this property to give a formal proof of the conjecture regarding complete semantics.

scholarly journals On Cycles, Attackers and Supporters --- A Contribution to The Investigation of Dynamics in Abstract Argumentation

2021 ◽  
Author(s):  
Ringo Baumann ◽  
Markus Ulbricht
Keyword(s):  
Knowledge Representation ◽  
Main Part ◽  
Research Area ◽  
Knowledge Representation And Reasoning ◽  
Major Research ◽  
Abstract Argumentation ◽  
Odd Cycle ◽  
The Impact ◽  
Odd Cycles

Abstract argumentation as defined by Dung in his seminal 1995 paper is by now a major research area in knowledge representation and reasoning. Dynamics of abstract argumentation frameworks (AFs) as well as syntactical consequences of semantical facts of them are the central issues of this paper. The first main part is engaged with the systematical study of the influence of attackers and supporters regarding the acceptability status of whole sets and/or single arguments. In particular, we investigate the impact of addition or removal of arguments, a line of research that has been around for more than a decade. Apart from entirely new results, we revisit, generalize and sum up similar results from the literature. To gain a comprehensive formal and intuitive understanding of the behavior of AFs we put special effort in comparing different kind of semantics. We concentrate on classical admissibility-based semantics and also give pointers to semantics based on naivity and weak admissibility, a recently introduced mediating approach. In the second main part we show how to infer syntactical information from semantical one. For instance, it is well-known that if a finite AF possesses no stable extension, then it has to contain an odd-cycle. In this paper, we even present a characterization of this issue. Moreover, we show that the change of the number of extensions if adding or removing an argument allows to conclude the existence of certain even or odd cycles in the considered AF without having further information.

scholarly journals A Check on Annotation in Sentiment Research

2019 ◽  
Vol 8 (2S8) ◽  
pp. 1346-1350
Keyword(s):  
Social Media ◽  
Sentiment Analysis ◽  
English Language ◽  
Research Area ◽  
Research Literature ◽  
Manual Annotation ◽  
Automatic Annotation ◽  
Annotation Method ◽  
New Concepts

The research literature on sentiment analysis methodologies has exponentially grown in recent years. In any research area, where new concepts and techniques are constantly introduced, it is, therefore, of interest to analyze the latest trends in this literature. In particular, we have chosen to primarily focus on the literature of the last five years, on annotation methodologies, including frequently used datasets and from which they were obtained. Based on the survey, it appears that researchers do more manual annotation in the formation of sentiment corpus. As for the dataset, there are still many uses of English language taken from social media such as Twitter. In this area of research, there are still many that need to be explored, such as the use of semi-automatic annotation method that is still very rarely used by researchers. Also, less popular languages, such as Malay, Korean, Japanese, and so on, still require corpus for sentiment analysis research.

The structure of norm Clifford algebras

2012 ◽  
Vol 62 (6) ◽  
Author(s):  
Hans Keller ◽  
Herminia Ochsenius
Keyword(s):  
Clifford Algebra ◽  
Classical Case ◽  
Canonical Representation ◽  
Inner Product ◽  
Infinite Products ◽  
Infinite Dimensional ◽  
Significant Step ◽  
Group Of Isometries ◽  
Inner Automorphisms ◽  
Special Case

AbstractOrthomodular Hilbertian spaces are infinite-dimensional inner product spaces (E, 〈·, ·〉) with the rare property that to every orthogonally closed subspace U ⊆ E there is an orthogonal projection from E onto U. These spaces, discovered about 30 years ago, are constructed over certain non-Archimedeanly valued, complete fields and are endowed with a non-Archimedean norm derived from the inner product. In a previous work [KELLER, H. A.—OCHSENIUS, H.: On the Clifford algebra of orthomodular spaces over Krull valued fields. In: Contemp. Math. 508, Amer. Math. Soc., Providence, RI, 2010, pp. 73–87] we described the construction of a new object, called the norm Clifford algebra C̃(E) associated to E. It can be considered a counterpart of the well-established Clifford algebra of a finite dimensional quadratic space. In contrast to the classical case, C̃(E) allows to represent infinite products of reflections by inner automorphisms. It is a significant step towards a better understanding of the group of isometries, which in infinite dimension is complex and hard to grasp.In the present paper we are concerned with the inner structure of these new algebras. We first give a canonical representation of the elements, and we prove that C̃ is always central. Then we focus on an outstanding special case in which C̃ is shown to be a division ring. Moreover, in that special case we completely describe the ideals of the corresponding valuation ring $$\mathcal{A}$$. It turns out, rather unexpectedly, that every left-ideal and every right-ideal of $$\mathcal{A}$$ is in fact bilateral.

A systematic analysis of identity based encryption (IBE)

2021 ◽  
Vol 25 (3) ◽  
pp. 343-356
Author(s):  
Aravind Karrothu ◽  
Jasmine Norman
Keyword(s):  
Research Area ◽  
Resource Constraint ◽  
Security Threats ◽  
Light Weight ◽  
Future Trends ◽  
Major Research ◽  
Systematic Analysis ◽  
Identity Based Encryption ◽  
Wide Range ◽  
Identity Based

Light-weight cryptography is a major research area due to the minimization of the size of the devices utilized for such services. The associated security threats do increase as their applications are more now. Identity-Based Encryption (IBE) with its wide range of cryptographic schemes and protocols is specifically found suitable for low-end devices that have much resource constraint. This work describes various schemes and protocols in IBE. In this paper an analysis of IBE schemes and the various attacks they are prone to are discussed. The future trends are found to be very promising and challenging.

scholarly journals 50 nm Scale Alignment Method for Hybrid Manufacturing Processes for Full 3D Structuring

2020 ◽  
Vol 21 (12) ◽  
pp. 2407-2417
Author(s):  
Ki-Hwan Jang ◽  
Hae-Sung Yoon ◽  
Hyun-Taek Lee ◽  
Eunseob Kim ◽  
Sung-Hoon Ahn
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Research Area ◽  
Manufacturing Processes ◽  
Alignment Error ◽  
Alignment Method ◽  
Major Research ◽  
Hybrid Processes

AbstractIn micro-/nano-scale, multi-material three-dimensional (3D), structuring has been a major research area for making various applications. To overcome dimensional and material limitations, several hybrid processes have been proposed. The hybrid processes were performed in the same or different numerically controlled stages. If the stages differed, the substrate was moved and locked to the stage before fabrication. During the locking, alignment error occurred. This error became problematic because this significantly compromised the quality of final structures. Here, an alignment method for a hybrid process consisted of a focused ion beam milling, aerodynamically focused nanoparticle printing, and micro-machining was developed. Two sets of collinear marks were placed at the edges of the substrate. Rotational and translational errors were calculated and compensated using the marks. Processes having different scales were bridged through this alignment method. Various materials were utilized, and accuracy was less than 50 nm when the length of the substrate was less than 13 mm. The alignment method was employed to fabricate a V-shaped structure and step-shaped structure using polymer, ceramic, and metal.

Diffraction, crystallography and microscopy beyond three dimensions: structural dynamics in space and time

2004 ◽  
Vol 363 (1827) ◽  
pp. 315-329 ◽  
Author(s):  
Ahmed H. Zewail
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Gas Phase ◽  
Structural Dynamics ◽  
Research Area ◽  
Three Dimensions ◽  
Ultrafast Electron Diffraction ◽  
Major Research ◽  
Condensed Media ◽  
Recent Developments

In this article we highlight recent developments of ultrafast electron diffraction and crystallography at Caltech. These developments have made it possible to resolve transient structures, both spatially (0.01 Å) and temporally (picosecond and now femtosecond), in the gas phase and condensed media—surfaces, interfaces, and crystals—with wide-ranging applications. With the extension to ultrafast electron microscopy, discussed here and elsewhere, we present an overview of one major research area at our centre, the Laboratory for Molecular Sciences.

scholarly journals To be or not to be: the early history of H 3 and H 3 +

2012 ◽  
Vol 370 (1978) ◽  
pp. 5225-5235 ◽  
Author(s):  
Helge Kragh
Keyword(s):  
Quantum Chemistry ◽  
Research Area ◽  
Early History ◽  
Active Hydrogen ◽  
Major Research ◽  
New Methods ◽  
History Of

Triatomic hydrogen became a major research area only after 1980, but its history goes back to J. J. Thomson’s discovery in 1911. In fact, the possible existence of H 3 was suggested as early as 1895. This paper outlines the history of H 3 and up to the mid-1930s, when chemists and physicists ceased to believe in the existence of the H 3 molecule. In the intervening years, there was a great deal of interest in ‘active hydrogen’ and also in the configuration of H 3 , which was examined by Bohr in 1919. While H 3 was abandoned, was not. Although the properties of were largely unknown, the existence of the ion was firmly established, and its structure studied by means of the new methods of quantum chemistry.

Research into Communicative Language Teaching

1987 ◽  
Vol 8 ◽  
pp. 109-125 ◽  
Author(s):  
Rosamond Mitchell
Keyword(s):  
Foreign Language ◽  
Language Teaching ◽  
Communicative Language Teaching ◽  
Research Literature ◽  
Major Research ◽  
Foreign Language Pedagogy ◽  
Language Pedagogy ◽  
Growing Body ◽  
Research Problems ◽  
Special Case

The problems of research into communicative language teaching are a special case of the problems facing research into any kind of foreign language pedagogy. They also overlap to a considerable degree with those facing any research in teaching, regardless of subject matter. This article reviews a range of research approaches which have been, or might be, used in researching various dimensions of communicative language teaching. It draws on the general literature on educational research methods to some extent, and on the general language pedagogy research literature, as well as on the growing body of research literature on communicative language teaching. This is not an exhaustive survey, however; instead, a limited number of studies are chosen for discussion so as to exemplify the major research problems and approaches.

scholarly journals Towards Electrochemical Water Desalination Techniques: A Review on Capacitive Deionization, Membrane Capacitive Deionization and Flow Capacitive Deionization

Membranes ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 96 ◽  
Author(s):  
Gbenro Folaranmi ◽  
Mikhael Bechelany ◽  
Philippe Sistat ◽  
Marc Cretin ◽  
Francois Zaviska
Keyword(s):  
Brackish Water ◽  
Research Area ◽  
Water Desalination ◽  
Ion Adsorption ◽  
Capacitive Deionization ◽  
Major Research ◽  
Modus Operandi ◽  
Solvated Ions ◽  
The 1960S ◽  
Simple Potential

Electrochemical water desalination has been a major research area since the 1960s with the development of capacitive deionization technique. For the latter, its modus operandi lies in temporary salt ion adsorption when a simple potential difference (1.0–1.4 V) of about 1.2 V is supplied to the system to temporarily create an electric field that drives the ions to their different polarized poles and subsequently desorb these solvated ions when potential is switched off. Capacitive deionization targets/extracts the solutes instead of the solvent and thus consumes less energy and is highly effective for brackish water. This paper reviews Capacitive Deionization (mechanism of operation, sustainability, optimization processes, and shortcomings) with extension to its counterparts (Membrane Capacitive Deionization and Flow Capacitive Deionization).

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