scholarly journals Tropical fans and the moduli spaces of tropical curves

2009 ◽  
Vol 145 (1) ◽  
pp. 173-195 ◽  
Author(s):  
Andreas Gathmann ◽  
Michael Kerber ◽  
Hannah Markwig
Keyword(s):  
Moduli Spaces ◽  
Building Blocks ◽  
Intersection Theory ◽  
Tropical Curves ◽  
Rigorous Definition ◽  
Definition Of ◽  
Tropical Varieties

AbstractWe give a rigorous definition of tropical fans (the ‘local building blocks for tropical varieties’) and their morphisms. For a morphism of tropical fans of the same dimension we show that the number of inverse images (counted with suitable tropical multiplicities) of a point in the target does not depend on the chosen point; a statement that can be viewed as one of the important first steps of tropical intersection theory. As an application we consider the moduli spaces of rational tropical curves (both abstract and in some ℝr) together with the evaluation and forgetful morphisms. Using our results this gives new, easy and unified proofs of various tropical independence statements, e.g. of the fact that the numbers of rational tropical curves (in any ℝr) through given points are independent of the points.

What’s in, what’s out? Towards a rigorous definition of the boundaries of benefit-cost analysis

2021 ◽  
pp. 1-17
Author(s):  
Daniel Acland
Keyword(s):  
Cost Analysis ◽  
Willingness To Pay ◽  
Low Cost ◽  
Consumer Sovereignty ◽  
Benefit Cost Analysis ◽  
Rigorous Definition ◽  
Pareto Criterion ◽  
Definition Of ◽  
Benefit Cost

Abstract Benefit-cost analysis (BCA) is typically defined as an implementation of the potential Pareto criterion, which requires inclusion of any impact for which individuals have willingness to pay (WTP). This definition is incompatible with the exclusion of impacts such as rights and distributional concerns, for which individuals do have WTP. I propose a new definition: BCA should include only impacts for which consumer sovereignty should govern. This is because WTP implicitly preserves consumer sovereignty, and is thus only appropriate for ‘sovereignty-warranting’ impacts. I compare the high cost of including non-sovereignty-warranting impacts to the relatively low cost of excluding sovereignty-warranting impacts.

scholarly journals Correction to: Masur–Veech volumes and intersection theory on moduli spaces of Abelian differentials

2021 ◽  
Author(s):  
Dawei Chen ◽  
Martin Möller ◽  
Adrien Sauvaget ◽  
Don Zagier
Keyword(s):  
Moduli Spaces ◽  
Intersection Theory ◽  
Abelian Differentials

A Correction to this paper has been published: https://doi.org/10.1007/s00222-020-00969-4

scholarly journals XML schema metrics for quality evaluation

2014 ◽  
Vol 11 (4) ◽  
pp. 1271-1289 ◽  
Author(s):  
Maja Pusnik ◽  
Marjan Hericko ◽  
Zoran Budimac ◽  
Bostjan Sumak
Keyword(s):  
Building Blocks ◽  
Xml Schema ◽  
Crucial Issue ◽  
Software Developers ◽  
Business Information Systems ◽  
Quality Aspects ◽  
Schema Development ◽  
Quality Aspect ◽  
Definition Of

In XML Schema development, the quality of XML Schemas is a crucial issue for further steps in the life cycle of an application, closely correlated with the structure of XML Schemas and different building blocks. Current research focuses on measuring complexity of XML Schemas and mainly do not consider other quality aspects. This paper proposes a novel quality measuring approach, based on existing software engineering metrics, additionally defining quality aspect of XML Schemas in the following steps: (1) definition of six schema quality aspects, (2) adoption of 25 directly measurable XML Schema variables, (3) proposition of six composite metrics, applying 25 measured variables and (4) composite metrics validation. An experiment using 250 standard XML Schemas collected from available e-business information systems was conducted. The results illustrate influence of XML Schema characteristics on its quality and evaluate applicability of metrics in the measurement process, a useful tool for software developers while building or adopting XML Schemas.

scholarly journals Regreso al vacío: sobre ausencia y desaparición social (Back to the void. Concerning absence and social disappearance)

2019 ◽  
Vol 9 (2) ◽  
pp. 183-197 ◽  
Author(s):  
Gabriel Gatti ◽  
Jaume Peris ◽  
Iñaki Robles Elong ◽  
Silvia Rodríguez Maeso ◽  
Ramón Sáez Valcárcel
Keyword(s):  
Rigorous Definition ◽  
Definition Of ◽  
Sobre Todo ◽  
The Disappeared

La ausencia es un tópico común en los textos que toman a la desaparición forzada o al desaparecido como objeto de interés. No es extraño, pues se han conseguido a partir de ese concepto resultados poderosos. Sin embargo, como en casi todo lo que se naturaliza, el contenido del concepto y de sus declinaciones ha perdido fuelle y cuesta saber de qué se habla cuando se habla de ausencia. Dentro del esfuerzo por construir una definición rigurosa de “desaparición social”, este texto regresa sobre el concepto, observa sus usos más instalados y sobre todo busca vías para volver a llenarlo de contenido. En este texto daremos algunos pasos en esa renovación. Absence is a common topic in the literature that analyzes forced disappearances and the disappeared. This is understandable because approaches from this concept have brought about remarkable insights. However, as it usually happens when something is naturalized, the concept’s content and its derivations have lost centrality and we find it hard to tell what’s the meaning of this concept. In an endeavor to develop a rigorous definition of “social disappearance”, this article looks back at the concept, focuses on its dominant uses and, above all, searches for ways to fill it with content. The present work moves forward with the renovation of this notion.

A Constraint Based Fuzzy Object Oriented Database Model

2011 ◽  
pp. 1-45 ◽  
Author(s):  
Guy de Tre ◽  
Rita de Caluwe
Keyword(s):  
Type System ◽  
Object Oriented ◽  
Building Blocks ◽  
Constraint System ◽  
Database Model ◽  
Database Models ◽  
Data Definition ◽  
Definition Of ◽  
Object Oriented Database ◽  
Adequate Data

The objective of this chapter is to define a fuzzy object-oriented formal database model that allows us to model and manipulate information in a (true to nature) natural way. Not all the elements (data) that occur in the real world are fully known or defined in a perfect way. Classical database models only allow the manipulation of accurately defined data in an adequate way. The presented model was built upon an object-oriented type system and an elaborated constraint system, which, respectively, support the definitions of types and constraints. Types and constraints are the basic building blocks of object schemes, which, in turn, are used for defining database schemes. Finally, the definition of the database model was obtained by providing adequate data definition operators and data manipulation operators. Novelties in the approach are the incorporation of generalized constraints and of extended possibilistic truth values, which allow for a better representation of data(base) semantics.

Semiconductor Quantum Dots

2021 ◽  
pp. 305-330
Keyword(s):  
Quantum Dots ◽  
Optoelectronic Devices ◽  
Building Blocks ◽  
Semiconductor Quantum Dots ◽  
Continuous Absorption ◽  
Semiconductor Particles ◽  
Spatial Dimensions ◽  
Definition Of ◽  
Narrow Emission

Semiconductor particles in the range of 2-10 nm are known as quantum dots (QDs) and nano-crystals where in all the three spatial dimensions, excitons are confined. Because of very small size and special electronic properties, QDs are expected to be building blocks of many electronic and optoelectronic devices. These particles possess tunable quantum efficiency, continuous absorption spectra, narrow emission and long term photostability. These are important for various biomedical applications. In this chapter definition of semiconductor QDs, their methods of preparation and characterization along with their properties and applications have been discussed.

Introduction

2020 ◽  
pp. 1-6
Author(s):  
Peter Scholze ◽  
Jared Weinstein
Keyword(s):  
Moduli Spaces ◽  
Function Fields ◽  
Number Fields ◽  
Important Special Case ◽  
Langlands Correspondence ◽  
Key Innovation ◽  
Perfectoid Spaces ◽  
Definition Of ◽  
Special Case

This introductory chapter provides an overview of Drinfeld's work on the global Langlands correspondence over function fields. Whereas the global Langlands correspondence is largely open in the case of number fields K, it is a theorem for function fields, due to Drinfeld and L. Lafforgue. The key innovation in this case is Drinfeld's notion of an X-shtuka (or simply shtuka). The Langlands correspondence for X is obtained by studying moduli spaces of shtukas. A large part of this course is about the definition of perfectoid spaces and diamonds. There is an important special case where the moduli spaces of shtukas are classical rigid-analytic spaces. This is the case of local Shimura varieties. Some examples of these are the Rapoport-Zink spaces.

Secondary Stresses in Airship Hull Structures

1927 ◽  
Vol 31 (204) ◽  
pp. 1073-1109
Author(s):  
J. F. Baker
Keyword(s):  
Cross Section ◽  
External Load ◽  
Structural Engineering ◽  
Secondary Stress ◽  
Rigorous Definition ◽  
The Cross ◽  
Definition Of ◽  
Redundant Structure ◽  
Ball Joints ◽  
External Loads

In no branch of structural engineering is there a rigorous definition of the term “secondary stress.”If the primary stresses in a structure are determined, that is, the stresses in the members due to an external load system, assuming that all the members are joined together by perfect pin- or ball-joints, then the secondary stresses are in general taken to be the additional stresses due to the rigidity of the actual joints used in practice.In such a highly redundant structure as an airship hull the labour involved, in determining even the primary stresses, precludes the use of the normal methods of stressing. It is usual to make use of generalised methods which give approximate results. These generalised methods imply that the external loads are applied to the structure in a certain distribution. Though this is rarely achieved, yet the results obtained are in most cases sufficiently accurate if suitable bracing is supplied to redistribute the external loads over the cross-section; the effect of the initial wrong distribution being then merely local.

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