scholarly journals A Virtual Class Calculus

2005 ◽  
Vol 34 (577) ◽  
Author(s):  
Erik Ernst ◽  
Klaus Ostermann ◽  
William Cook
Keyword(s):  
Programming Languages ◽  
Large Scale ◽  
Object Identity ◽  
New Family ◽  
Original Definition ◽  
Virtual Class ◽  
Virtual Classes ◽  
Program Composition ◽  
Definition Of ◽  
Open Question

Virtual classes are class-valued attributes of objects.<br />Like virtual methods, virtual classes are defined in<br />an object’s class and may be redefined within subclasses.<br />They resemble inner classes, which are also<br />defined within a class, but virtual classes are accessed<br />through object instances, not as static components<br />of a class. When used as types, virtual classes depend<br />upon object identity – each object instance introduces<br />a new family of virtual class types. Virtual classes support large-scale program composition techniques,<br />including higher-order hierarchies and family<br />polymorphism. The original definition of virtual<br />classes in Beta left open the question of static type<br />safety, since some type errors were not caught until<br />runtime. Later the languages Caesar and gbeta have<br />used a more strict static analysis in order to ensure<br />static type safety. However, the existence of a sound,<br />statically typed model for virtual classes has been a<br />long-standing open question. This technical report<br />presents a virtual class calculus, vc, that captures<br />the essence of virtual classes in these full-fledged programming languages. The key contributions of the<br />paper are a formalization of the dynamic and static<br />semantics of vc and a proof of the soundness of vc.<br />Categories: D.3.3 [Language Constructs and Features]:<br />Classes and objects, inheritance, polymorphism.<br />F.3.3 [Studies of Program Constructs]:<br />Object-oriented constructs, type structure. F.3.2<br />[Semantics of Programming Languages]: Operational<br />semantics.

scholarly journals The continuing lure of the mediated centre in times of deep mediatization: Media Events and its enduring legacy

2017 ◽  
Vol 40 (1) ◽  
pp. 114-117 ◽  
Author(s):  
Nick Couldry ◽  
Andreas Hepp
Keyword(s):  
Media Effects ◽  
Large Scale ◽  
Economic Viability ◽  
Media Events ◽  
Original Definition ◽  
Discrete Media ◽  
New Challenges ◽  
Definition Of ◽  
Integrated Media

Dayan and Katz’s book Media Events was so crucial because it challenged the dominance of quantitative communications research focused on measurable discrete ‘media effects’. But meanwhile new challenges have emerged which we called ‘deep mediatization’ – datafication, deeper fragmentation of the audience, and over the longer-term threats to the underlying economic viability of the large-scale integrated media producers that could put on ‘media events’. This makes it necessary to rethink the original definition of media events.

scholarly journals The Computational Complexity of Structure-Based Causality

2017 ◽  
Vol 58 ◽  
pp. 431-451 ◽  
Author(s):  
Gadi Aleksandrowicz ◽  
Hana Chockler ◽  
Joseph Y. Halpern ◽  
Alexander Ivrii
Keyword(s):  
Computational Complexity ◽  
Complexity Classes ◽  
Final Version ◽  
New Family ◽  
Original Definition ◽  
Np Complete ◽  
Definition Of

Halpern and Pearl introduced a definition of actual causality; Eiter and Lukasiewicz showed that computing whether X = x is a cause of Y = y is NP-complete in binary models (where all variables can take on only two values) and Σ^P_2 -complete in general models. In the final version of their paper, Halpern and Pearl slightly modified the definition of actual cause, in order to deal with problems pointed out by Hopkins and Pearl. As we show, this modification has a nontrivial impact on the complexity of computing whether {X} = {x} is a cause of Y = y. To characterize the complexity, a new family D_k^P , k = 1, 2, 3, . . ., of complexity classes is introduced, which generalises the class DP introduced by Papadimitriou and Yannakakis (DP is just D_1^P). We show that the complexity of computing causality under the updated definition is D_2^P -complete. Chockler and Halpern extended the definition of causality by introducing notions of responsibility and blame, and characterized the complexity of determining the degree of responsibility and blame using the original definition of causality. Here, we completely characterize the complexity using the updated definition of causality. In contrast to the results on causality, we show that moving to the updated definition does not result in a difference in the complexity of computing responsibility and blame.

Extending XQuery with pattern matching over XML, HTML and JSON, and its usage for data mining

2014 ◽  
Author(s):  
Benito van der Zander
Keyword(s):  
Data Mining ◽  
Programming Languages ◽  
Pattern Matching ◽  
Large Scale ◽  
General Pattern ◽  
Real Thing ◽  
Functional Programming Languages ◽  
Large Scale Data ◽  
Definition Of ◽  
Scale Data

Pattern matching in a broad sense is a common feature of modern functional programming languages, answering the question, if one complex structured object has a form that is the same as another complex structured object, for some definition of “the same”. In XQuery path expressions, switch, and typeswitch statements are often described as performing pattern matching, but these are merely impoverished flavors of matching when compared to the real thing. We describe a syntax for general pattern matching based on regular expressions for XML/HTML/JSONiq trees, how these patterns are matched against input data, and how this pattern matching can be integrated into the syntax and semantics of the XQuery language. At the end we summarize real-world experience using it for large-scale data mining of library webcatalogs.

scholarly journals Model driven engineering of a tableau algorithm for description logics

2009 ◽  
Vol 6 (1) ◽  
pp. 23-43 ◽  
Author(s):  
Nenad Krdzavac ◽  
Dragan Gasevic ◽  
Vladan Devedzic
Keyword(s):  
Programming Languages ◽  
Description Logics ◽  
Abstract Syntax ◽  
Model Driven Engineering ◽  
Model Driven ◽  
Model Repository ◽  
Tableau Algorithm ◽  
Original Definition ◽  
Concrete Syntax ◽  
Definition Of

This paper presents a method for implementing tableau algorithm for description logics (DLs). The architectures of the present DL reasoners such as RACER or FaCT were developed using programming languages as Java or LISP. The implementations are not based on original definition of the abstract syntax, but they require transformation of abstract syntax into concrete syntax implementation languages use. In order to address these issues, we propose the use of model-driven engineering principles for the development of a DL reasoner where a definition of a DL abstract syntax is provided by means of metamodels. The presented approach is based on the use of a MOF-based model repository and QVT-like transformations, which transform models compliant to the DL metamodel taken from the OMG's Ontology Definition Metamodel specification into models compliant to the Tableau metamodel defined in this paper. .

scholarly journals Generalized disconnection exponents

2020 ◽  
Author(s):  
Wei Qian
Keyword(s):  
Physical Interpretation ◽  
Acta Math ◽  
General Version ◽  
Multiple Points ◽  
New Family ◽  
The Family ◽  
Definition Of ◽  
Open Question ◽  
Brownian Loop ◽  
Critical Intensity

Abstract We introduce and compute the generalized disconnection exponents$$\eta _\kappa (\beta )$$ η κ ( β ) which depend on $$\kappa \in (0,4]$$ κ ∈ ( 0 , 4 ] and another real parameter $$\beta $$ β , extending the Brownian disconnection exponents (corresponding to $$\kappa =8/3$$ κ = 8 / 3 ) computed by Lawler, Schramm and Werner (Acta Math 187(2):275–308, 2001; Acta Math 189(2):179–201, 2002) [conjectured by Duplantier and Kwon (Phys Rev Lett 61:2514–2517, 1988)]. For $$\kappa \in (8/3,4]$$ κ ∈ ( 8 / 3 , 4 ] , the generalized disconnection exponents have a physical interpretation in terms of planar Brownian loop-soups with intensity $$c\in (0,1]$$ c ∈ ( 0 , 1 ] , which allows us to obtain the first prediction of the dimension of multiple points on the cluster boundaries of these loop-soups. In particular, according to our prediction, the dimension of double points on the cluster boundaries is strictly positive for $$c\in (0,1)$$ c ∈ ( 0 , 1 ) and equal to zero for the critical intensity $$c=1$$ c = 1 , leading to an interesting open question of whether such points exist for the critical loop-soup. Our definition of the exponents is based on a certain general version of radial restriction measures that we construct and study. As an important tool, we introduce a new family of radial SLEs depending on $$\kappa $$ κ and two additional parameters $$\mu , \nu $$ μ , ν , that we call radial hypergeometric SLEs. This is a natural but substantial extension of the family of radial $$\hbox {SLE}_\kappa (\rho )s$$ SLE κ ( ρ ) s .

CONCEPT OF THE IMPROVEMENT OF A KEY PUBLIC SPACE (USING THE EXAMPLE OF «ALLEY OF ARCHITECTS», VORONEZH)

2020 ◽  
pp. 97-109
Author(s):  
С. Л. Подвальный ◽  
О. А. Сотникова ◽  
Я. А. Золотухина
Keyword(s):  
Urban Environment ◽  
Public Space ◽  
Large Scale ◽  
Economic Value ◽  
Ecological Condition ◽  
Territory Design ◽  
Definition Of ◽  
The City ◽  
Modern Technologies ◽  
Intensive Growth

Постановка задачи. В настоящее время формирование современной комфортной городской среды приобретает особое социально-экономическое значение и выдвигается в число приоритетных государственных масштабных программ. В связи с этим необходимо разработать концепцию благоустройства ключевого общественного пространства, а именно: определить основные и сопутствующие функции данной территории, создать эскизное предложение проекта благоустройства с учетом всех необходимых норм и стандартов, внедрить современные технологии. Результаты. Выполнен эскизный дизайн-проект «Аллеи архитекторов» по ул. Орджоникидзе г. Воронеж, включающий в себя основные элементы по зонированию территории, проектированию акцентных объектов и внедрению инновационных технологий «умного города», позволяющих повысить уровень комфорта горожан. Выводы. Благоустройство населенных мест приобретает особое значение в условиях дискомфорта среды. С выполнением комплекса мероприятий, направленных на благоустройство, и с внедрением современных технологий значительно улучшается экологическое состояние, внешний облик города. Оздоровление и модернизация среды, которая окружает человека в городе, благотворно влияет на психофизическое состояние, что особенно важно в период интенсивного роста городов. Statement of the problem. Currently the formation of the modern comfortable urban environment is gaining a special social and economic value and moving forward in the priorities of state large-scale programs. The purpose of development of the concept of improvement of public space is definition of the main and accompanying functions of this territory, design of the outline offer of the project of improvement considering all necessary norms and standards and implementation of modern technologies. Results. The conceptual project of “Alley of Architects” includes the basic elements of territory zoning, design of accent objects and implementation of technologies of a “smart-city”. These elements allow one to increase the level of comfort of inhabitants. Conclusions. Improvement of the inhabited places is of particular importance in the conditions of discomfort of the environment. Carrying out a complex of the actions directed to gardening and improvement, introducing modern technologies, the ecological condition, the physical appearance of the city considerably improves. Improvement and modernization of the environment which surrounds the person in the city influences a psychophysical state well that especially important during intensive growth of the cities.

Bottlenecks in the Implementation of On-Site Wastewater Treatment Plants on a Large Scale in The Netherlands

1990 ◽  
Vol 22 (3-4) ◽  
pp. 291-298
Author(s):  
Frits A. Fastenau ◽  
Jaap H. J. M. van der Graaf ◽  
Gerard Martijnse
Keyword(s):  
Wastewater Treatment ◽  
The Netherlands ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Housing Stock ◽  
Research Work ◽  
Field Research ◽  
Domestic Wastewater ◽  
Research Programme ◽  
Definition Of

More than 95 % of the total housing stock in the Netherlands is connected to central sewerage systems and in most cases the wastewater is treated biologically. As connection to central sewerage systems has reached its economic limits, interest in on-site treatment of the domestic wastewater of the remaining premises is increasing. A large scale research programme into on-site wastewater treatment up to population equivalents of 200 persons has therefore been initiated by the Dutch Ministry of Housing, Physical Planning and Environment. Intensive field-research work did establish that the technological features of most on-site biological treatment systems were satisfactory. A large scale implementation of these systems is however obstructed in different extents by problems of an organisational, financial and/or juridical nature and management difficulties. At present research is carried out to identify these bottlenecks and to analyse possible solutions. Some preliminary results are given which involve the following ‘bottlenecks':-legislation: absence of co-ordination and absence of a definition of ‘surface water';-absence of subsidies;-ownership: divisions in task-setting of Municipalities and Waterboards; divisions involved with cost-sharing;-inspection; operational control and maintenance; organisation of management;-discharge permits;-pollution levy;-sludge disposal. Final decisions and practical elaboration of policies towards on-site treatment will have to be formulated in a broad discussion with all the authorities and interest groups involved.

Random graphs

2018 ◽  
Author(s):  
Mark Newman
Keyword(s):  
Random Graph ◽  
Random Graphs ◽  
Large Scale ◽  
Random Network ◽  
Graph Model ◽  
Clustering Coefficient ◽  
Giant Component ◽  
Random Graph Model ◽  
Definition Of ◽  
Average Size

An introduction to the mathematics of the Poisson random graph, the simplest model of a random network. The chapter starts with a definition of the model, followed by derivations of basic properties like the mean degree, degree distribution, and clustering coefficient. This is followed with a detailed derivation of the large-scale structural properties of random graphs, including the position of the phase transition at which a giant component appears, the size of the giant component, the average size of the small components, and the expected diameter of the network. The chapter ends with a discussion of some of the shortcomings of the random graph model.

Populism and Liberal Democracy

2019 ◽  
Author(s):  
Takis S. Pappas
Keyword(s):  
United States ◽  
Liberal Democracy ◽  
The United States ◽  
Comprehensive Theory ◽  
The People ◽  
Original Definition ◽  
Key Issues ◽  
Great Relevance ◽  
Definition Of

Based on an original definition of modern populism as “democratic illiberalism” and many years of meticulous research, Takis Pappas marshals extraordinary empirical evidence from Argentina, Greece, Peru, Italy, Venezuela, Ecuador, Hungary, the United States, Spain, and Brazil to develop a comprehensive theory about populism. He addresses all key issues in the debate about populism and answers significant questions of great relevance for today’s liberal democracy, including: • What is modern populism and how can it be differentiated from comparable phenomena like nativism and autocracy? • Where in Latin America has populism become most successful? Where in Europe did it emerge first? Why did its rise to power in the United States come so late? • Is Trump a populist and, if so, could he be compared best with Venezuela’s Chávez, France’s Le Pens, or Turkey’s Erdoğan? • Why has populism thrived in post-authoritarian Greece but not in Spain? And why in Argentina and not in Brazil? • Can populism ever succeed without a charismatic leader? If not, what does leadership tell us about how to challenge populism? • Who are “the people” who vote for populist parties, how are these “made” into a group, and what is in their minds? • Is there a “populist blueprint” that all populists use when in power? And what are the long-term consequences of populist rule? • What does the expansion, and possibly solidification, of populism mean for the very nature and future of contemporary democracy? Populism and Liberal Democracy will change the ways the reader understands populism and imagines the prospects of liberal democracy.

Research on Hyperpaths in the Urban Rail Transit Network

2014 ◽  
Vol 488-489 ◽  
pp. 1439-1443
Author(s):  
Jin Hai Li ◽  
Jian Feng Liu
Keyword(s):  
Large Scale ◽  
Urban Rail Transit ◽  
Rail Transit ◽  
Transit Network ◽  
Travel Costs ◽  
Urban Rail ◽  
Distinctive Structure ◽  
Feasible Path ◽  
Definition Of ◽  
Urban Rail Transit Network

Hyperpaths enumeration is one of the basic procedures in many traffic planning issues. As a result of its distinctive structure, hyperpaths in Urban Rail Transit Network (URTN) are different from those in road network. Typically, one may never visit a station more than once and would never transfer from one line to another that has been visited in a loopless URTN, meaning that stations a hyperpath traversed cannot be repeated, neither do lines in loopless networks. This paper studies the relationships between feasible path and the shortest path in terms of travel costs. In this paper, a new definition of hyperpath in URTN is proposed and a new algorithm based on the breadth first searching (BFS) method is presented to enumerate the hyperpaths. The algorithm can safely avoid hyperpath omission and can even be applied in networks containing loops as well. The influence of parameters on hyperpaths is studied by experimentally finding hyperpaths in the subway network in Beijing. A group of suggested parameter pairs are then given. Finally, a numerical experiment is used to illustrate the validity of the proposed algorithm. The results imply the significance of the convergence of the BFS algorithm which can be used to search hyperpaths in large scale URTN even with loop.

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