scholarly journals PRYM VARIETIES AND THE INFINITE GRASSMANNIAN

1998 ◽  
Vol 09 (01) ◽  
pp. 75-93 ◽  
Author(s):  
FRANCISCO J. PLAZA MARTÍN
Keyword(s):  
Dynamical Systems ◽  
Moduli Space ◽  
Point Of View ◽  
Base Field ◽  
Prym Varieties ◽  
Arbitrary Base ◽  
Bkp Hierarchy ◽  
Definition Of

In this paper we study Prym varieties and their moduli space using the well-known techniques of the infinite Grassmannian. There are three main results of this paper: a new definition of the BKP hierarchy over an arbitrary base field (that generalizes the classical one over [Formula: see text]); a characterization of Prym varieties in terms of dynamical systems, and explicit equations for the moduli space of (certain) Prym varieties. For all of these problems the language of the infinte Grassmannian, in its algebro-geometric version, allows us to deal with these problems from the same point of view.

On the Dynamic Isotropy of Mechanisms With Two Degrees of Freedom

2005 ◽  
Author(s):  
Raffaele Di Gregorio ◽  
Alessandro Cammarata ◽  
Rosario Sinatra
Keyword(s):  
Finite Number ◽  
Degrees Of Freedom ◽  
Point Of View ◽  
Closed Curves ◽  
Special Cases ◽  
Dynamic Performances ◽  
Definition Of ◽  
Geometric Locus

The comparison of mechanisms with different topology or with different geometry, but with the same topology, is a necessary operation during the design of a machine sized for a given task. Therefore, tools that evaluate the dynamic performances of a mechanism are welcomed. This paper deals with the dynamic isotropy of 2-dof mechanisms starting from the definition introduced in a previous paper. In particular, starting from the condition that identifies the dynamically isotropic configurations, it shows that, provided some special cases are not considered, 2-dof mechanisms have at most a finite number of isotropic configurations. Moreover, it shows that, provided the dynamically isotropic configurations are excluded, the geometric locus of the configuration space that collects the points associated to configurations with the same dynamic isotropy is constituted by closed curves. This results will allow the classification of 2-dof mechanisms from the dynamic-isotropy point of view, and the definition of some methodologies for the characterization of the dynamic isotropy of these mechanisms. Finally, examples of applications of the obtained results will be given.

Definition of Roofing Slate Lithotypes for an International Roofing Slate Classification

2020 ◽  
Vol 848 ◽  
pp. 48-57 ◽  
Author(s):  
Victor Cárdenes ◽  
Álvaro Rubio-Ordoñez ◽  
Vicente G. Ruiz de Argandona
Keyword(s):  
Life Expectancy ◽  
Carbon Emissions ◽  
Bending Strength ◽  
Construction Materials ◽  
Point Of View ◽  
Technical Data ◽  
General Classification ◽  
The World ◽  
Definition Of

The term “roofing slate” comprises all natural rocks that can be used for roofing. Some of the characteristics that define their performance as construction materials are water absorption, bending strength, mineral composition, and aesthetics. From a sustainability point of view, roofing slates also have the largest life expectancy and lowest carbon emissions of all covering materials. This work reviews the constructive characteristics of roofing slates, from technical data provided by producers from all over the world. These data, supported by the petrological characterization of several roofing slate samples, are used to propose a general classification for this special type of rock. Thus, roofing slates are sorted in twelve lithotypes, depending of their petrographical characteristics, defined by the color. The resulting classification is named International Roofing Slate Classification (IRSC), formally defined in this paper.

scholarly journals A generalized type semigroup and dynamical comparison

2020 ◽  
pp. 1-18
Author(s):  
XIN MA
Keyword(s):  
Dynamical Systems ◽  
Compact Hausdorff Space ◽  
Discrete Group ◽  
Hausdorff Space ◽  
Countable Discrete Group ◽  
Higher Dimensional ◽  
Definition Of ◽  
Generalized Type

In this paper, we construct and study a semigroup associated to an action of a countable discrete group on a compact Hausdorff space that can be regarded as a higher dimensional generalization of the type semigroup. We study when this semigroup is almost unperforated. This leads to a new characterization of dynamical comparison and thus answers a question of Kerr and Schafhauser. In addition, this paper suggests a definition of comparison for dynamical systems in which neither the acting group is necessarily amenable nor the action is minimal.

scholarly journals Constructive Characterization of Gorongosa National Park Villages

2020 ◽  
Author(s):  
Michael Santos ◽  
Ana Ferreira ◽  
Dinis Gardete
Keyword(s):  
National Park ◽  
Visual Observation ◽  
Point Of View ◽  
Characterization Methods ◽  
Earth Systems ◽  
Natural Park ◽  
Different Shapes ◽  
Definition Of ◽  
Wooden Structures

The Gorongosa National Park was created in 1960 and it has 4.067km2 that integrates the Serra da Gorongosa and the local communities that live nearby. This work aims the characterization of the traditional houses and ways of building observed in the natural park. The main objective is the identification and characterization of constructive systems and the organization of villages in the Gorongosa National Park. This characterization is intended to be constructive from the point of view of the materials, geometry and solutions applied on the construction. The present work has many phases, in this sense the following stages were defined: Developing the state of art based on the analysis of constructive characterization methods and bibliographic research on earth systems used in Mozambique and other countries with similar conditions and climates; Definition of the studying cases: identification of the villages that were objects of studies, definition of survey criteria and registration; Visiting the villages and surveying the solutions through photographic register, visual observation, measurements, interviews; Registering identification files to each solution, etc. The work presents the typologies of construction found, namely: constructions with walls made from earth commonly used in the country, being the most usual technology the earth covering over wooden structures with different geometries and pieces of different shapes and dimensions. The study has documented some of the most current solutions in National Park.

Understanding functional illiteracy from a policy, adult education, and cognition point of view: Towards a joint referent framework

2019 ◽  
Vol 30 (2) ◽  
pp. 109-122
Author(s):  
Aleksandar Bulajić ◽  
Miomir Despotović ◽  
Thomas Lachmann
Keyword(s):  
Adult Education ◽  
Operational Definition ◽  
Literacy Skills ◽  
Point Of View ◽  
Industrialized Countries ◽  
Functional Illiteracy ◽  
Scale Levels ◽  
Components Of Reading ◽  
The One ◽  
Definition Of

Abstract. The article discusses the emergence of a functional literacy construct and the rediscovery of illiteracy in industrialized countries during the second half of the 20th century. It offers a short explanation of how the construct evolved over time. In addition, it explores how functional (il)literacy is conceived differently by research discourses of cognitive and neural studies, on the one hand, and by prescriptive and normative international policy documents and adult education, on the other hand. Furthermore, it analyses how literacy skills surveys such as the Level One Study (leo.) or the PIAAC may help to bridge the gap between cognitive and more practical and educational approaches to literacy, the goal being to place the functional illiteracy (FI) construct within its existing scale levels. It also sheds more light on the way in which FI can be perceived in terms of different cognitive processes and underlying components of reading. By building on the previous work of other authors and previous definitions, the article brings together different views of FI and offers a perspective for a needed operational definition of the concept, which would be an appropriate reference point for future educational, political, and scientific utilization.

Dosimetry and optimization in digital radiography based on the contrast-detail resolution

2018 ◽  
Vol 6 (3) ◽  
Author(s):  
Wilson Otto Gomes Batista ◽  
Alexandre Gomes De Carvalho
Keyword(s):  
Image Quality ◽  
Inverse Image ◽  
Point Of View ◽  
Complete Analysis ◽  
Portable Devices ◽  
Evaluation Tool ◽  
Air Kerma ◽  
Direct Radiography ◽  
Definition Of ◽  
Entrance Surface Air Kerma

Contrast-detail (C-D) curves are useful in evaluating the radiographic image quality in a global way. The objective of the present study was to obtain the C-D curves and the inverse image quality figure. Both of these parameters were used as an evaluation tool for abdominal and chest imaging protocols. The C-D curves were obtained with the phantom CDRAD 2.0 in computerized radiography and the direct radiography systems (including portable devices). The protocols were 90 and 102 kV in the range of 2 to 20 mAs for the chest and 80 kV in the range of 10 to 80 mAs for the abdomen. The incident air kerma values were evaluated with a solid state sensor. The analysis of these C-D curves help to identify which technique would allow a lower value of the entrance surface air kerma, Ke, while maintaining the image quality from the point of view of C-D detectability. The results showed that the inverse image quality figure, IQFinv, varied little throughout the range of mAs, while the value of Ke varied linearly directly with the mAs values. Also, the complete analysis of the curves indicated that there was an increase in the definition of the details with increasing mAs. It can be concluded that, in the transition phase for the use of the new receptors, it is necessary to evaluate and adjust the practised protocols to ensure, at a minimum, the same levels of the image quality, taking into account the aspects of the radiation protection of the patient.

DIRECTIONS OF ASSOCIATIVE IDENTIFICATION OF PERSONAL NAMES

2019 ◽  
Vol 18 (28) ◽  
pp. 118-128
Author(s):  
Olena Karpenko ◽  
Tetiana Stoianova
Keyword(s):  
Proper Names ◽  
Mental Lexicon ◽  
Point Of View ◽  
Sound Symbolism ◽  
Personal Names ◽  
Communicative Process ◽  
Proper Name ◽  
Definition Of ◽  
Scientific Value ◽  
The Brain

The article is devoted to the study of personal names from a cognitive point of view. The study is based on the cognitive concept that speech actually exists not in the speech, not in linguistic writings and dictionaries, but in consciousness, in the mental lexicon, in the language of the brain. The conditions for identifying personal names can encompass not only the context, encyclopedias, and reference books, but also the sound form of the word. In the communicative process, during a free associative experiment, which included a name and a recipient’s mental lexicon. The recipient was assigned a task to quickly give some association to the name. The aggregate of a certain number of reactions of different recipients forms the associative field of a proper name. The associative experiment creates the best conditions for identifying the lexeme. The definition of a monosemantic personal name primarily includes the search of what it denotes, while during the process of identifying a polysemantic personal name recipients tend have different reactions. Scientific value is posed by the effect of the choice of letters for the name, sound symbolism, etc. The following belong to the generalized forms of identification: usage of a hyperonym; synonyms and periphrases or simple descriptions; associations denoting the whole (name stimulus) by reference to its part (associatives); cognitive structures such as “stimulus — association” and “whole (stimulus) — part (associative)”; lack of adjacency; mysterious associations. The topicality of the study is determined by its perspective to identify the directions of associative identification of proper names, which is one of the branches of cognitive onomastics. The purpose of the study is to identify, review, and highlight the directions of associative identification of proper names; the object of the research is the names in their entirety and variety; its subject is the existence of names in the mental lexicon, which determines the need for singling out the directions for the associative identification of the personal names.

The Analyses of Learning Strategies in English as a Second Language: Theoretical Classification and Measurement Test

2020 ◽  
Vol 4 (2) ◽  
pp. 118-129
Author(s):  
Asti Gumartifa ◽  
◽  
Indah Windra Dwie Agustiani
Keyword(s):  
Language Learning ◽  
Learning Outcomes ◽  
Learning Strategies ◽  
Learning Process ◽  
English Learners ◽  
English Language ◽  
Point Of View ◽  
Effective Learning ◽  
The Impact

Gaining English language learning effectively has been discussed all years long. Similarly, Learners have various troubles outcomes in the learning process. Creating a joyful and comfortable situation must be considered by learners. Thus, the implementation of effective learning strategies is certainly necessary for English learners. This descriptive study has two purposes: first, to introduce the classification and characterization of learning strategies such as; memory, cognitive, metacognitive, compensation, social, and affective strategies that are used by learners in the classroom and second, it provides some questionnaires item based on Strategy of Inventory for Language Learning (SILL) version 5.0 that can be used to examine the frequency of students’ learning strategies in the learning process. The summary of this study explains and discusses the researchers’ point of view on the impact of learning outcomes by learning strategies used. Finally, utilizing appropriate learning strategies are certainly beneficial for both teachers and learners to achieve the learning target effectively.

DEFINITION OF THE PUBLIC SECURITY AND ORDERLINESS ENSURING MECHANISM IN UKRAINE

2018 ◽  
Vol 1 (11) ◽  
pp. 155-163
Author(s):  
Marina Aleksandrovna Kalievskaya
Keyword(s):  
Human Rights ◽  
Development Strategy ◽  
State Policy ◽  
The State ◽  
Point Of View ◽  
Public Security ◽  
National Priority ◽  
Institu Tions ◽  
Protection Of Human Rights ◽  
Definition Of

In this article, a model of the mechanism of ensuring public security and orderliness in accordance with the principles and tasks of the relevant institu- tions in public administration, taking into account resources, technologies, mea- sures for the state policy implementation in the spheres of ensuring the protection of human rights and freedoms, the interests of society and the state, combating crime, maintaining public security and order. It was found that ensuring public security and order in Ukraine is a mechanism for the implementation of national goals of state policy in the areas of ensuring the protection of human rights and freedoms, the interests of society and the state, combating crime, maintaining public security and order, by defining tasks according to certain principles. The idea is that if one considers the state policy in the spheres of ensuring the protec- tion of human rights and freedoms, the interests of society and the state, combat- ing crime, maintaining public security and order as a national priority (purpose, task), then the mechanism of ensuring public security and order in Ukraine needs coordination with the state development strategy. From the point of view of the implementation of the state policy in the areas of ensuring the protection of hu- man rights and freedoms, the interests of society and the state, combating crime, maintaining public security and order, the mechanism of ensuring public security and order in Ukraine can be considered as the main system providing intercon- nection such elements as institutions (implementing the specified state policy), resources (human resources, logistical, natural and so on, with the help of which it is possible to implement state policy), technologies (skills, knowledge, means and so on the implementation of state policy), measures (action plans), as well as external (internal) threats.

The Algorithm of Characterization of an Action as a Jointly Committed Crime

2018 ◽  
pp. 37-44
Keyword(s):  
Criminal Code ◽  
Point Of View

The article discusses a sequence of activities to identify a crime as jointly committed. The requirements to the algorithm of such activities are formulated. Programme-based and targeted methods applied by the authors allowed detecting a range of stages of the algorithm. The first four stages aim at defining mandatory elements of a crime allowing to characterize it as a jointly committed action. The rest of the stages focus on identifying a type of criminal complicity. In the article, each stage is described. It is emphasized that in each stage there is a special objective. At the same time, all these stages, taken together, constitute a separate module of the program of criminal characterization of an action. From the authors’ point of view, algorithms are necessary not only for detection of crimes and their criminal characterization, but also for answering the question on existence of criminal complicity in each case. Also the authors give their opinions on interpretation of criminal complicity as a legal category. In particular, it is emphasized that not all of crimes merely committed with participation of two or more persons should be understood as jointly committed. It is joint participation that makes a crime jointly committed. Various forms of criminal complicity and types of co-offenders are considered in the article as well. In various crimes, criminal complicity manifests itself differently. Therefore the proposed algorithm can be applied only after identification a specific article of the Russian Criminal Code stipulating the responsibility for the crime committed.

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