scholarly journals Augmented, free and tensor generalized digroups

2019 ◽  
Vol 17 (1) ◽  
pp. 71-88
Author(s):  
José Gregorio Rodríguez-Nieto ◽  
Olga P. Salazar-Díaz ◽  
Raúl Velásquez
Keyword(s):  
Semidirect Product ◽  
Trivial Extension ◽  
Natural Form ◽  
Structural Result ◽  
Equivariant Map ◽  
The One ◽  
Classical Construction

Abstract The concept of generalized digroup was proposed by Salazar-Díaz, Velásquez and Wills-Toro in their paper “Generalized digroups” as a non trivial extension of groups. In this way, many concepts and results given in the category of groups can be extended in a natural form to the category of generalized digroups. The aim of this paper is to present the construction of the free generalized digroup and study its properties. Although this construction is vastly different from the one given for the case of groups, we will use this concept, the classical construction for groups and the semidirect product to construct the tensor generalized digroup as well as the semidirect product of generalized digroups. Additionally, we give a new structural result for generalized digroups using compatible actions of groups and an equivariant map from a group set to the group corresponding to notions of associative dialgebras and augmented racks.

scholarly journals A Remark on the Van Lieshout and Baddeley J-Function for Point Processes

1997 ◽  
Vol 29 (1) ◽  
pp. 19-25 ◽  
Author(s):  
T. Bedford ◽  
J. Van Den Berg
Keyword(s):  
Point Process ◽  
Stationary Point ◽  
Point Processes ◽  
Spatial Interaction ◽  
Empty Space ◽  
Stationary Point Process ◽  
Space Function ◽  
The One ◽  
Classical Construction

The empty space function of a stationary point process in ℝd is the function that assigns to each r, r > 0, the probability that there is no point within distance r of O. In a recent paper Van Lieshout and Baddeley study the so-called J-function, which is defined as the ratio of the empty space function of a stationary point process and that of its corresponding reduced Palm process. They advocate the use of the J-function as a characterization of the type of spatial interaction.Therefore it is natural to ask whether J ≡ 1 implies that the point process is Poisson. We restrict our analysis to the one-dimensional case and show that a classical construction by Szász provides an immediate counterexample. In this example the interpoint distances are still exponentially distributed. This raises the question whether it is possible to have J ≡ 1 but non-exponentially distributed interpoint distances. We construct a point process with J ≡ 1 but where the interpoint distances are bounded.

scholarly journals On the Principles of Design of Transport Nodes

2022 ◽  
Vol 19 (4) ◽  
pp. 6-12
Author(s):  
P. A. Kozlov ◽  
S. P. Vakulenko ◽  
V. P. Kozlova ◽  
N. Yu. Evreenova
Keyword(s):  
Rational Design ◽  
Systemic Approach ◽  
Transport Systems ◽  
Natural Form ◽  
Basic Principles ◽  
Main Method ◽  
Principles Of Design ◽  
The One ◽  
Definition Of

The methodology developed by the authors refers to designing, calculating, and optimising transport nodes based on the original systemic approach as a main method. The use of the methodology will make it possible to design transport nodes more rationally and to evaluate their development projects more correctly.A «system» is understood as a general natural form of structuring organised substance, which enables it to function stably in a changeable environment. The basic principles are formulated as follows: the system consists of elements, each of which is also a system; active self-maintenance is developed in the system, that is, active actions are counteracting external adverse influences; it is shown that self-maintenance is provided by adaptability, and in transport systems the self-maintenance is particularly provided by adaptive technology.A contradiction (a dialectical one) arises: on the one hand, the elements are independent systems that have their own system parameters and mechanisms for their active maintenance, and on the other hand, they are subordinate creatures capable of flexibly changing their work to maintain the parameters of the supersystem. It is necessary to find harmony between the levels of development of these opposite properties. Transport nodes are also considered from these systemic positions. Exposition of several definitions of nodes by leading national scientists is followed by a statement showing that they all contradict the new systemic approach.Suggested system definition of a node describes it as a set of stations. The authors also propose a new classification of transport nodes, formulate criteria for their rational design depending on the classes, and propose correct design and optimisation principles. 

scholarly journals Decoding Covert Speech From EEG-A Comprehensive Review

2021 ◽  
Vol 15 ◽  
Author(s):  
Jerrin Thomas Panachakel ◽  
Angarai Ganesan Ramakrishnan
Keyword(s):  
Formal Education ◽  
Vocal Communication ◽  
Brain Activity ◽  
Activity Patterns ◽  
Machine Learning Algorithms ◽  
Human Beings ◽  
Natural Form ◽  
Practical Applications ◽  
The One

Over the past decade, many researchers have come up with different implementations of systems for decoding covert or imagined speech from EEG (electroencephalogram). They differ from each other in several aspects, from data acquisition to machine learning algorithms, due to which, a comparison between different implementations is often difficult. This review article puts together all the relevant works published in the last decade on decoding imagined speech from EEG into a single framework. Every important aspect of designing such a system, such as selection of words to be imagined, number of electrodes to be recorded, temporal and spatial filtering, feature extraction and classifier are reviewed. This helps a researcher to compare the relative merits and demerits of the different approaches and choose the one that is most optimal. Speech being the most natural form of communication which human beings acquire even without formal education, imagined speech is an ideal choice of prompt for evoking brain activity patterns for a BCI (brain-computer interface) system, although the research on developing real-time (online) speech imagery based BCI systems is still in its infancy. Covert speech based BCI can help people with disabilities to improve their quality of life. It can also be used for covert communication in environments that do not support vocal communication. This paper also discusses some future directions, which will aid the deployment of speech imagery based BCI for practical applications, rather than only for laboratory experiments.

scholarly journals A Remark on the Van Lieshout and Baddeley J-Function for Point Processes

1997 ◽  
Vol 29 (01) ◽  
pp. 19-25 ◽  
Author(s):  
T. Bedford ◽  
J. Van Den Berg
Keyword(s):  
Point Process ◽  
Stationary Point ◽  
Point Processes ◽  
Spatial Interaction ◽  
Empty Space ◽  
Stationary Point Process ◽  
Space Function ◽  
The One ◽  
Classical Construction

The empty space function of a stationary point process in ℝd is the function that assigns to each r, r > 0, the probability that there is no point within distance r of O. In a recent paper Van Lieshout and Baddeley study the so-called J-function, which is defined as the ratio of the empty space function of a stationary point process and that of its corresponding reduced Palm process. They advocate the use of the J-function as a characterization of the type of spatial interaction. Therefore it is natural to ask whether J ≡ 1 implies that the point process is Poisson. We restrict our analysis to the one-dimensional case and show that a classical construction by Szász provides an immediate counterexample. In this example the interpoint distances are still exponentially distributed. This raises the question whether it is possible to have J ≡ 1 but non-exponentially distributed interpoint distances. We construct a point process with J ≡ 1 but where the interpoint distances are bounded.

scholarly journals Forest and Labyrinth. Toward an Ecology of the Subject

2021 ◽  
Vol 31 (3) ◽  
pp. 219-248
Keyword(s):  
Subjective Experience ◽  
Black Box ◽  
Roland Barthes ◽  
The Other ◽  
Modern Period ◽  
The Face ◽  
The Subject ◽  
The Stability ◽  
The One ◽  
Classical Construction

The concept of the subject is articulated here as a correlation between two terms — movements and actions. Classical theories of action presupposed the subject as a unique way to correlate movements and actions and to translate the one into the other. The “soul,” i.e., a natural complex of cognitive and volitional abilities, was a reliable tool for that translation. However, the modern period faces the problem of “the failure of the soul,” which brings about the concept of the subject. Different ways of translating movements into actions do not always permit stable subjectification, which indicates that “transport” is a mediating term in the opposition of movements and actions. There is an intermediary region between the “physics” of movement and the “ethics” of action, and that region is the “logic” of transport which is to be understood as an open-ended collection of ways to correlate movements with actions. The problematic function of transport becomes clear when it is impossible to rely on the soul as a black box that is responsible for the stability in the translation of movements into actions. The solution to the problem of the failure of the soul appears particularly in Henry David Thoreau’s “forest,” which is constructed as a way to restore a classical ecology of the subject in the face of a proliferation of different modes of transport that threaten the uniformity of subjective experience. According to Roland Barthes’ seminar, the opposite of Thoreau’s “forest” would be the “labyrinth” as an anti-subject machine. The labyrinth is not merely a place of loss, but the production of loss that turns any movement into action or decision while at the same time cancelling any action and drawing the subject out of its own structure. Labyrinth and forest as alternatives to the classical construction of the subject delineate a general space for subjectification, which has problems that cannot be encompassed by theories of praxis.

scholarly journals The Slippery Path to Total Presence: How Omnidirectional Virtual Reality Treadmills Influence the Gaming Experience

2021 ◽  
Vol 9 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Lars-Ole Wehden ◽  
Felix Reer ◽  
Robin Janzik ◽  
Wai Yen Tang ◽  
Thorsten Quandt
Keyword(s):  
Virtual Reality ◽  
Experimental Design ◽  
Empirical Research ◽  
User Experience ◽  
Virtual World ◽  
Digital Games ◽  
Factorial Experimental Design ◽  
Natural Form ◽  
Potential Benefits ◽  
The One

Researchers, game designers, and consumers place great hopes into the potential benefits of virtual reality (VR) technology on the user experience in digital games. Indeed, initial empirical research has shown that VR technology can improve the gaming experience in a number of ways compared to traditional desktop gaming, for instance by amplifying immersion and flow. However, on the downside, a mismatch between physical locomotion and the movements of the avatar in the virtual world can also lead to unpleasant feelings when using VR technology—often referred to as cybersickness. One solution to this problem may be the implementation of novel passive repositioning systems (also called omnidirectional treadmills) that are designed to allow a continuous, more natural form of locomotion in VR. In the current study, we investigate how VR technology and the use of an omnidirectional treadmill influence the gaming experience. Traditional desktop gaming, VR gaming, and omnidirectional treadmill gaming are compared in a one-factorial experimental design (<em>N</em> = 203). As expected, we found that VR gaming on the one hand leads to higher levels of flow, presence, and enjoyment, but at the same time also is accompanied by higher levels of cybersickness than traditional desktop gaming. The use of the omnidirectional treadmill did not significantly improve the gaming experience and also did not reduce cybersickness. However, this more physically demanding form of locomotion may make omnidirectional treadmills interesting for exergame designers.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Nucleation of Disorder in Fe3Al Alloys

1967 ◽  
Vol 25 ◽  
pp. 312-313
Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Antiphase Domain ◽  
Effect Of Temperature ◽  
Domain Structures ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Higher Temperature ◽  
The One

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.

Fundamental Research into Thin Films in a Developing Country

1972 ◽  
Vol 30 ◽  
pp. 500-501
Author(s):  
J.A. Eades ◽  
E. Grünbaum
Keyword(s):  
Thin Films ◽  
Growth Process ◽  
Empirical Process ◽  
Nucleation And Growth ◽  
Research Groups ◽  
Film Research ◽  
Fundamental Research ◽  
Controlled Deposition ◽  
The One ◽  
The University

In the last decade and a half, thin film research, particularly research into problems associated with epitaxy, has developed from a simple empirical process of determining the conditions for epitaxy into a complex analytical and experimental study of the nucleation and growth process on the one hand and a technology of very great importance on the other. During this period the thin films group of the University of Chile has studied the epitaxy of metals on metal and insulating substrates. The development of the group, one of the first research groups in physics to be established in the country, has parallelled the increasing complexity of the field.The elaborate techniques and equipment now needed for research into thin films may be illustrated by considering the plant and facilities of this group as characteristic of a good system for the controlled deposition and study of thin films.

STM studies of crystal growth

1991 ◽  
Vol 49 ◽  
pp. 374-375
Author(s):  
M. G. Lagally
Keyword(s):  
Crystal Growth ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Sputter Deposition ◽  
Field Of View ◽  
Scanning Tunneling ◽  
Wide Field ◽  
Tunneling Microscopy ◽  
Wide Field Of View ◽  
The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

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