28,074 research outputs found
Encouraging versatile thinking in algebra using the computer
In this article we formulate and analyse some of the obstacles to understanding the notion of a variable, and the use and meaning of algebraic notation, and report empirical evidence to support the hypothesis that an approach using the computer will be more successful in overcoming these obstacles. The computer approach is formulated within a wider framework ofversatile thinking in which global, holistic processing complements local, sequential processing. This is done through a combination of programming in BASIC, physical activities which simulate computer storage and manipulation of variables, and specific software which evaluates expressions in standard mathematical notation. The software is designed to enable the user to explore examples and non-examples of a concept, in this case equivalent and non-equivalent expressions. We call such a piece of software ageneric organizer because if offers examples and non-examples which may be seen not just in specific terms, but as typical, or generic, examples of the algebraic processes, assisting the pupil in the difficult task of abstracting the more general concept which they represent. Empirical evidence from several related studies shows that such an approach significantly improves the understanding of higher order concepts in algebra, and that any initial loss in manipulative facility through lack of practice is more than made up at a later stage
A Constraint Programming Approach for Mining Sequential Patterns in a Sequence Database
Constraint-based pattern discovery is at the core of numerous data mining
tasks. Patterns are extracted with respect to a given set of constraints
(frequency, closedness, size, etc). In the context of sequential pattern
mining, a large number of devoted techniques have been developed for solving
particular classes of constraints. The aim of this paper is to investigate the
use of Constraint Programming (CP) to model and mine sequential patterns in a
sequence database. Our CP approach offers a natural way to simultaneously
combine in a same framework a large set of constraints coming from various
origins. Experiments show the feasibility and the interest of our approach
Focusing for Pronoun Resolution in English Discourse: An Implementation
Anaphora resolution is one of the most active research areas in natural
language processing. This study examines focusing as a tool for the resolution
of pronouns which are a kind of anaphora. Focusing is a discourse phenomenon
like anaphora. Candy Sidner formalized focusing in her 1979 MIT PhD thesis and
devised several algorithms to resolve definite anaphora including pronouns. She
presented her theory in a computational framework but did not generally
implement the algorithms. Her algorithms related to focusing and pronoun
resolution are implemented in this thesis. This implementation provides a
better comprehension of the theory both from a conceptual and a computational
point of view. The resulting program is tested on different discourse segments,
and evaluation and analysis of the experiments are presented together with the
statistical results.Comment: iii + 49 pages, compressed, uuencoded Postscript file; revised
version of the first author's Bilkent M.S. thesis, written under the
supervision of the second author; notify Akman via e-mail
([email protected]) or fax (+90-312-266-4126) if you are unable to
obtain hardcopy, he'll work out somethin
Gathering Statistics to Aspectually Classify Sentences with a Genetic Algorithm
This paper presents a method for large corpus analysis to semantically
classify an entire clause. In particular, we use cooccurrence statistics among
similar clauses to determine the aspectual class of an input clause. The
process examines linguistic features of clauses that are relevant to aspectual
classification. A genetic algorithm determines what combinations of linguistic
features to use for this task.Comment: postscript, 9 pages, Proceedings of the Second International
Conference on New Methods in Language Processing, Oflazer and Somers ed
Harnessing Higher-Order (Meta-)Logic to Represent and Reason with Complex Ethical Theories
The computer-mechanization of an ambitious explicit ethical theory, Gewirth's
Principle of Generic Consistency, is used to showcase an approach for
representing and reasoning with ethical theories exhibiting complex logical
features like alethic and deontic modalities, indexicals, higher-order
quantification, among others. Harnessing the high expressive power of Church's
type theory as a meta-logic to semantically embed a combination of quantified
non-classical logics, our work pushes existing boundaries in knowledge
representation and reasoning. We demonstrate that intuitive encodings of
complex ethical theories and their automation on the computer are no longer
antipodes.Comment: 14 page
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