1,005,227 research outputs found
The C++0x "Concepts" Effort
C++0x is the working title for the revision of the ISO standard of the C++
programming language that was originally planned for release in 2009 but that
was delayed to 2011. The largest language extension in C++0x was "concepts",
that is, a collection of features for constraining template parameters. In
September of 2008, the C++ standards committee voted the concepts extension
into C++0x, but then in July of 2009, the committee voted the concepts
extension back out of C++0x.
This article is my account of the technical challenges and debates within the
"concepts" effort in the years 2003 to 2009. To provide some background, the
article also describes the design space for constrained parametric
polymorphism, or what is colloquially know as constrained generics. While this
article is meant to be generally accessible, the writing is aimed toward
readers with background in functional programming and programming language
theory. This article grew out of a lecture at the Spring School on Generic and
Indexed Programming at the University of Oxford, March 2010
Pregeometric Concepts on Graphs and Cellular Networks as Possible Models of Space-Time at the Planck-Scale
Starting from the working hypothesis that both physics and the corresponding
mathematics have to be described by means of discrete concepts on the
Planck-scale, one of the many problems one has to face is to find the discrete
protoforms of the building blocks of continuum physics and mathematics. In the
following we embark on developing such concepts for irregular structures like
(large) graphs or networks which are intended to emulate (some of) the generic
properties of the presumed combinatorial substratum from which continuum
physics is assumed to emerge as a coarse grained and secondary model theory. We
briefly indicate how various concepts of discrete (functional) analysis and
geometry can be naturally constructed within this framework, leaving a larger
portion of the paper to the systematic developement of dimensional concepts and
their properties, which may have a possible bearing on various branches of
modern physics beyond quantum gravity.Comment: 16 pages, Invited paper to appear in the special issue of the Journal
of Chaos, Solitons and Fractals on: "Superstrings, M, F, S ... Theory" (M.S.
El Naschie, C. Castro, Editors
Ab initio explanation of disorder and off-stoichiometry in Fe-Mn-Al-C kappa carbides
Carbides play a central role for the strength and ductility in many
materials. Simulating the impact of these precipitates on the mechanical
performance requires the knowledge about their atomic configuration. In
particular, the C content is often observed to substantially deviate from the
ideal stoichiometric composition. In the present work, we focus on Fe-Mn-Al-C
steels, for which we determined the composition of the nano-sized kappa
carbides (Fe,Mn)3AlC by atom probe tomography (APT) in comparison to larger
precipitates located in grain boundaries. Combining density functional theory
with thermodynamic concepts, we first determine the critical temperatures for
the presence of chemical and magentic disorder in these carbides. Secondly, the
experimentally observed reduction of the C content is explained as a compromise
between the gain in chemical energy during partitioning and the elastic strains
emerging in coherent microstructures
Using formal metamodels to check consistency of functional views in information systems specification
UML notations require adaptation for applications such as Information Systems (IS). Thus we have defined IS-UML. The purpose of this article is twofold. First, we propose an extension to this language to deal with functional aspects of IS. We use two views to specify IS transactions: the first one is defined as a combination of behavioural UML diagrams (collaboration and state diagrams), and the second one is based on the definition of specific classes of an extended class diagram. The final objective of the article is to consider consistency issues between the various diagrams of an IS-UML specification. In common with other UML languages, we use a metamodel to define IS-UML. We use class diagrams to summarize the metamodel structure and a formal language, B, for the full metamodel. This allows us to formally express consistency checks and mapping rules between specific metamodel concepts. (C) 2007 Elsevier B.V. All rights reserved
CS 3180/5180: Comparative Languages
This course will introduce fundamental concepts and paradigms underlying the design of modern programming languages. For concreteness, we study the details of an object-oriented language (e.g. Java, C#, C++), a functional language (e.g., Scheme, and get introduced to multiparadigm languages (e.g., Python, Scala). The overall goal is to enable comparison and evaluation of existing languages. The programming assignments will largely be coded in Java and in Scheme, and optionally in Python or Scala
Team Leadership Approaches for Corporate Project Managers
The study of Critical and Creative Thinking (C&CT) methods introduced me to a number of new approaches and tools that have vital and practical applications for today’s corporate team leaders. The primary purpose of my paper and the Genuity Inc. case example, is to demonstrate how these C&CT approaches and tools can be used by corporate team leaders to motivate, direct and lead their teams. Towards this end I have organized my paper into two major sections: 1) In the first, I lay the groundwork by defining the challenges facing today’s project managers and the cross-functional teams they lead. 2) In the second section, I introduce and discuss C&CT concepts for analyzing and defining thinking styles of team members, and how this knowledge can be used by project managers for more effective leadership. The concepts covered will help team leaders address the wide range of challenges they face today. These concepts include the conceptual blocks to better problem solving, including common barriers to creative thinking, cultural blocks, emotional blocks, perceptual blocks, and intellectual blocks, as described by James Adams in Conceptual Blockbusting, a Guide to Better Ideas
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