scholarly journals AN APERIODIC TILE WITH EDGE-TO-EDGE ORIENTATIONAL MATCHING RULES

2021 ◽  
pp. 1-29
Author(s):  
James J. Walton ◽  
Michael F. Whittaker
Keyword(s):  
Central Idea ◽  
Dynamical Spectrum ◽  
Matching Rule ◽  
Simple Rules ◽  
New Type ◽  
Aperiodic Tile ◽  
Model Set ◽  
Matching Rules ◽  
Almost All ◽  
Uniquely Ergodic

Abstract We present a single, connected tile which can tile the plane but only nonperiodically. The tile is hexagonal with edge markings, which impose simple rules as to how adjacent tiles are allowed to meet across edges. The first of these rules is a standard matching rule, that certain decorations match across edges. The second condition is a new type of matching rule, which allows tiles to meet only when certain decorations in a particular orientation are given the opposite charge. This forces the tiles to form a hierarchy of triangles, following a central idea of the Socolar–Taylor tilings. However, the new edge-to-edge orientational matching rule forces this structure in a very different way, which allows for a surprisingly simple proof of aperiodicity. We show that the hull of all tilings satisfying our rules is uniquely ergodic and that almost all tilings in the hull belong to a minimal core of tilings generated by substitution. Identifying tilings which are charge-flips of each other, these tilings are shown to have pure point dynamical spectrum and a regular model set structure.

The ESRF Insertion Devices

1998 ◽  
Vol 5 (3) ◽  
pp. 196-201 ◽  
Author(s):  
Joel Chavanne ◽  
Pascal Elleaume ◽  
Pierre Van Vaerenbergh
Keyword(s):  
Synchrotron Radiation ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
European Synchrotron Radiation Facility ◽  
Harmonic Numbers ◽  
New Type ◽  
Almost All ◽  
Field Errors ◽  
Field Integral ◽  
Significant Effort

The European Synchrotron Radiation facility is presently operating 47 segments of insertion devices (IDs). A record brilliance of 1 × 1020 photons s−1 (0.1% bandwidth)−1 mm−2 mrad−2 has been reached. Almost all devices are built with permanent magnets with or without iron pole pieces. They have been mechanically and magnetically designed and field-measured in house. Multipole shimming has been applied to all devices to remove the integrated dipole and higher-order multipole fields, thereby reducing the interaction between the IDs and the stored beam. For all undulators, the field errors have been corrected further using spectrum shimming in order to achieve ideal spectral brilliance on all harmonic numbers from 1 to 15. A significant effort has been made to optimize the magnet terminations for both field-integral correction and phasing. A phasing scheme of the undulator segments has been developed which allows the independent manufacture and operation of individual segments. Several designs for undulator phasing are presented, together with a comparison between hybrid and pure-permanent-magnet technology. A new type of variable-polarization helical undulator is presented.

scholarly journals Simplicial systems for interval exchange maps and measured foliations

1985 ◽  
Vol 5 (2) ◽  
pp. 257-271 ◽  
Author(s):  
S. P. Kerckhoff
Keyword(s):  
General Theorem ◽  
Interval Exchange ◽  
Alternative Proof ◽  
Simple Assumption ◽  
Refinement Process ◽  
Almost All ◽  
Interval Exchange Maps ◽  
Uniquely Ergodic

AbstractThe spaces of interval exchange maps and measured foliations are considered and an alternative proof that almost all interval exchange maps and measured foliations are uniquely ergodic is given. These spaces are endowed with a refinement process, called a simplicial system, which is studied abstractly and is shown to be normal under a simple assumption. The results follow and thus are a corollary of a more general theorem in a broader setting.

scholarly journals On the communicative nature of electronic culture

2021 ◽  
Vol 21 (4) ◽  
pp. 390-394
Author(s):  
Olga Yu. Golub ◽  
Keyword(s):  
Large Scale ◽  
Social Institutions ◽  
Legal Norms ◽  
Social Communities ◽  
Digital World ◽  
Electronic Culture ◽  
The Social ◽  
New Type ◽  
Communication Approach ◽  
Almost All

The Internet, as the global communication channel, is a factor systemically transforming all social reality. Digitalization of almost all spheres of life, communications virtualization and the expansion of network interactions lead to deep changes in the social structure, social institutions, sociocultural mechanisms for the functioning of society and revising ethical and legal norms. Transformation changes of a large-scale sociocultural context generate a new type of culture. The article gives the theoretical and methodological substantiation of the phenomenon of modern electronic culture within the communication approach. It is concluded that the formation of digital world culture is conditioned by all types of communication, allowing for the social and cultural interactions of individuals and social communities.

scholarly journals The psycho-pedagogical profile of a tutor in e-learning

2012 ◽  
Vol 1 (1-2) ◽  
pp. 99-113
Author(s):  
Maria Goga
Keyword(s):  
Technological Change ◽  
Labour Market ◽  
Training Module ◽  
Face To Face ◽  
Qualified Personnel ◽  
The World ◽  
E Learning ◽  
New Type ◽  
Almost All ◽  
Phd Thesis

In a society based on knowledge, in a continuous economic social and educational changing, there is the need of qualified people to cope with the avalanche of new innovative ideas. The labour market in Europe and around the world increasingly requires highly trained and qualified personnel to meet the requirements of rapid technological change in almost all the areas of life. Teaching virtually is different that teaching face-to-face. In this article we make a summary of the research done within the context of the PhD thesis of the author which investigates this new type of learning and skills and it manages staff roles - tutors - and suggests in this regard a training module for this new profession. The research was performed with institutions from Romania and from other countries in Europe, U.S.A., and Asia.

Religious education in Russia and Europe in the twentieth century: historical experience and transfer of values

2020 ◽  
Keyword(s):  
Twentieth Century ◽  
Religious Education ◽  
State Intervention ◽  
Historical Experience ◽  
Christian Churches ◽  
Variety Of Groups ◽  
The Future ◽  
History Of ◽  
New Type ◽  
Almost All

The twentieth century was a time of trial for the Christian Churches of Europe and Russia. Their clash with a new type of state could not but affect the system of religious education. In almost all countries, it has faced state intervention, which has led to its significant transformation, and sometimes even a complete ban. At the same time, there was a search for new forms of religious education aimed at a wide variety of groups: from future priests and lay students to teenagers and preschoolers. This collection of articles provides reviews of these trends, as well as reviews of current discussions about the future of religious education. For historians, teachers and anyone interested in the history of religious education.

scholarly journals An alternative approach to the ergodic theory of measured foliations on surfaces

1981 ◽  
Vol 1 (4) ◽  
pp. 461-488 ◽  
Author(s):  
Mary Rees
Keyword(s):  
Projective Space ◽  
Lebesgue Measure ◽  
Ergodic Theory ◽  
Diffeomorphism Group ◽  
Alternative Approach ◽  
Interval Exchanges ◽  
Almost All ◽  
Uniquely Ergodic

AbstractWe consider measured foliations on surfaces, and interval exchanges. We give alternative proofs of the following theorems first proved by Masur and (independently) Veech. The action of the diffeomorphism group of the surface on the projective space of measured foliations (with respect to a natural ‘Lebesgue’ measure) is ergodic. Almost all measured foliations are uniquely ergodic. Almost all interval exchanges (again, with respect to a natural ‘Lebesgue’ measure) are uniquely ergodic.

Deviation for interval exchange transformations

1997 ◽  
Vol 17 (6) ◽  
pp. 1477-1499 ◽  
Author(s):  
ANTON ZORICH
Keyword(s):  
Ergodic Theorem ◽  
Gauss Map ◽  
Interval Exchange ◽  
Actual Number ◽  
Interval Exchange Transformation ◽  
Exchange Transformation ◽  
Interval Exchange Transformations ◽  
Starting Point ◽  
Almost All ◽  
Uniquely Ergodic

Consider a long piece of a trajectory $x, T(x), T(T(x)), \ldots, T^{n-1}(x)$ of an interval exchange transformation $T$. A generic interval exchange transformation is uniquely ergodic. Hence, the ergodic theorem predicts that the number $\chi_i(x,n)$ of visits of our trajectory to the $i$th subinterval would be approximately $\lambda_i n$. Here $\lambda_i$ is the length of the corresponding subinterval of our unit interval $X$. In this paper we give an estimate for the deviation of the actual number of visits to the $i$th subinterval $X_i$ from one predicted by the ergodic theorem.We prove that for almost all interval exchange transformations the following bound is valid: $$ \max_{\ssty x\in X \atop \ssty 1\le i\le m} \limsup_{n\to +\infty} \frac {\log | \chi_i(x,n) -\lambda_in|}{\log n} = \frac{\theta_2}{\theta_1} < 1. $$ Roughly speaking the error term is bounded by $n^{\theta_2/\theta_1}$. The numbers $0\le \theta_2 < \theta_1$ depend only on the permutation $\pi$ corresponding to the interval exchange transformation (actually, only on the Rauzy class of the permutation). In the case of interval exchange of two intervals we obviously have $\theta_2=0$. In the case of exchange of three and more intervals the numbers $\theta_1, \theta_2$ are the two top Lyapunov exponents related to the corresponding generalized Gauss map on the space of interval exchange transformations.The limit above ‘converges to the bound’ uniformly for all $x\in X$ in the following sense. For any $\varepsilon >0$ the ratio of logarithms would be less than $\theta_2(\pi)/\theta_1(\pi)+\varepsilon $ for all $n\ge N(\varepsilon)$, where $N(\varepsilon)$ does not depend on the starting point $x\in X$.

Negative Selection Algorithm Based on Double Matching Rules

2011 ◽  
Vol 204-210 ◽  
pp. 42-45 ◽  
Author(s):  
Yu Hu ◽  
Bin Li
Keyword(s):  
False Alarm ◽  
False Alarm Rate ◽  
Negative Selection ◽  
Hamming Distance ◽  
Network Intrusion Detection ◽  
Selection Algorithm ◽  
Matching Rule ◽  
Negative Selection Algorithm ◽  
Network Intrusion ◽  
Matching Rules

The theory of artificial immune had been widely used in the research of network intrusion detection. Nowadays, the existing detector generating algorithms based on negative selection usually use a certain matching rule, as a result, too many detectors may generate, and the false alarm rate will become more serious. This paper proposes an improved negative selection algorithm using double matching rule: candidate detectors should be selected by the improved Hamming distance matching first, then the remaining detectors go through the segmented r-chunks(rch) matching rule. Experiments show that compared with traditional algorithms, this method brings a small number and more efficient detectors, reduces the false alarm rate and guarantees the efficiency of detectors.

scholarly journals Contemporary Trends in the Development of Databases

2021 ◽  
Vol 27 (1) ◽  
pp. 5-15
Keyword(s):  
Relational Databases ◽  
Point Of View ◽  
Nosql Databases ◽  
Advantages And Disadvantages ◽  
Different Types ◽  
Long Time ◽  
Structured Information ◽  
New Type ◽  
Operational Activities ◽  
Almost All

Databases have been established for a long time as an efficient and reliable technology for organizing and storing data in almost all areas of human activity. In addition to their widespread use in the operational activities of practically all enterprises and organizations, they are also sources of data for research and analysis of economic processes. Databases were developed rapidly in the second half of the 20th century and as a result relational databases emerged, which are an extremely powerful tool for storing and accessing data. Since the beginning of the 21st century, with the extraordinary increase in the volume of stored and processed information, as well as the significant part of unstructured and semi-structured information, a new type of databases, named NoSQL databases, have emerged and developed. The article attempts to define the characteristics of different types of databases, analyzing their advantages and disadvantages and outlining their areas of application on this basis. The trends in the development of the databases from the point of view of the author are also presented.

scholarly journals CONSULT ANALYSIS OF EFFECTIVE ENTREPRENEURSHIP IN THE PERIOD OF QUARANTINE RESTRICTIONS IN UKRAINE AND THE WORLD

2021 ◽  
Author(s):  
Anna Chkan ◽  
Iryna Chkan
Keyword(s):  
Economic Crisis ◽  
New Technologies ◽  
Financial Resources ◽  
Current Crisis ◽  
Special Support ◽  
Foreign Countries ◽  
The World ◽  
Operational Management ◽  
New Type ◽  
Almost All

The article deals with problems in the activity of enterprises in the conditions of the new modern crisis  pandemic. The purpose of the research is to identify the most priority and effective tools and measures of effective entrepreneurship for enterprises in a pandemic  a new type of socio-economic crisis in the world. In the article the consult-analysis of the activities of enterprises by the authors was conducted. The authors have determined that the current socio-economic crisis has significant differences from all previous crises that took place in the economy of the world. It is determined that today the enterprises of almost all branches of the national economy find themselves in a situation where they simply do not have sufficient financial resources, lose their profit through of fluctuations in the exchange rates, must operate in a new way, have to implement new technologies of operational management, have to completely change the technology of work with consumers or even suspend their activity on indefinite term. According to the research, most of the enterprises, even in the situation when they continued their activity, can work for quite a limited time. In this aspect, the expediency of developing and implementing a set of measures by the state of supporting the entrepreises in crisis and post-crisis periods has been proved. As the priority were determined different areas: preferential taxation, compensation of wages paid to employees, introduction of a temporary moratorium on checks. The practice of foreign countries (Poland, Italy, Germany, France, Britain, USA) on the protection of entrepreneurs in the crisis is analyzed. Most of these countries financially support entrepreneurs and the population, introduce preferential taxation on the results of their activities, and create special support funds. The authors summarize in the article the set of measures implemented in Ukraine for small and large businesses. On the whole, the authors identified that measures that have been developed in Ukraine to support business, help in the current crisis, but most of the measures are not enough productive, their implementation has some limitations and difficulties.

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