12,131 research outputs found
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
Quasi-Freestanding Multilayer Graphene Films on the Carbon Face of SiC
The electronic band structure of as-grown and doped graphene grown on the
carbon face of SiC is studied by high-resolution angle-resolved photoemission
spectroscopy, where we observe both rotations between adjacent layers and
AB-stacking. The band structure of quasi-freestanding AB- bilayers is directly
compared with bilayer graphene grown on the Si-face of SiC to study the impact
of the substrate on the electronic properties of epitaxial graphene. Our
results show that the C-face films are nearly freestanding from an electronic
point of view, due to the rotations between graphene layers.Comment: http://link.aps.org/doi/10.1103/PhysRevB.81.24141
Running anti-de Sitter radius from QCD-like strings
We consider renormalization effects for a bosonic QCD-like string, whose
partons have propagators instead of Gaussian. Classically this model
resembles (the bosonic part of) the projective light-cone (zero-radius) limit
of a string on an AdS background, where Schwinger parameters give rise to
the fifth dimension. Quantum effects generate dynamics for this dimension,
producing an AdS background with a running radius. The projective
light-cone is the high-energy limit: Holography is enforced dynamically.Comment: 12 page
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Competitively Evolving Decision Trees Against Fixed Training Cases for Natural Language Processing
Competitive fitness functions can generate performance superior to absolute fitness functions [Angelineand Pollack 1993], [Hillis 1992]. This chapter describes a method by which competition can be implemented when training over a fixed (static) set of examples. Since new training cases cannot be generated by mutation or crossover, the probabilistic frequencies by which individual training cases are selected competitively adapt. We evolve decision trees for the problem of word sense disambiguation. The decision trees contain embedded bit strings; bit string crossover is intermingled with subtree-swapping. To approach the problem of overlearning, we have implemented a fitness penalty function specialized for decision trees which is dependent on the partition of the set of training cases implied by a decision tree
The Effect of Modeling on Cooperation in the Laboratory and in the Natural Environment
In this study a multiple-baseline design was used to determine the effectiveness of three different modeling sequences in increasing cooperative behavior in children in a laboratory situation. The research also assessed the short- and long-term effects of the laboratory procedures on children\u27s behavior in a free-play setting.
Subjects were 9 pairs of preschool-aged children. In the laboratory situation pairs of subjects performed a block-stacking task which allowed them to respond either cooperatively or independently. Following baseline periods of varying lengths , the pairs of children were exposed to one of three videotapes of cooperative models . In Tape l adult models demonstrated cooperative behavior, but exhibited no verbal behavior. In Tape 2 the models made positive statements about cooperation contiguous with the demonstration of cooperative behavior. In Tape 3 the models demonstrated cooperation, made contiguous positive statements about cooperation, and in addition, they received differential positive reinforcement for cooperation.
Although three of nine teams showed a significant increase in mutually cooperative responding, consistent multiple baseline control was not demonstrated . Therefore, it could not be conclusively stated that the videotaped cooperative models were effective in increasing children\u27s mutually cooperative responding in the laboratory.
A significant increase in parallel play was noted between laboratory partners in free-play periods immediately following the laboratory sessions; however, this increased interaction was not obvious when 5-day and 6-week follow-up observations were made
Development of Cooperation Between Children in the Minimal Social Situation
The purpose of this study was to determine whether children can learn to cooperate in what has been described as the minimal social situation. The research also compared the effectiveness of verbal instructions and a training task for teaching subjects the win-stay, lose-change rule. This rule has been used to explain the development of cooperation in the minimal social situation.
Subjects were 19 teams of first-, second-, and third-graders. Five teams were composed of two girls; six were girl-boy teams; and eight were boy-boy teams. Ten of the 19 teams learned to cooperate in the minimal social situation without treatment. Two of four teams given the rule training procedure learned to cooperate after having failed to learn under typical minimal social conditions. Of five teams given verbal instructions, four learned to cooperate immediately.
The probability of following the win-stay, lose-change rule was approximately 50% initially and did not increase significantly in later sessions. It is not clear then that following this rule is a prerequisite for the development of a cooperative exchange. Explanations in the literature which suggest subjects learn a single rule, i.e., win-stay, lose-change, may be misleading since children evidenced a variety of rules, any of which might have been reinforced or punished over the course of the experiment
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