341,103 research outputs found
Recommended from our members
Heuristics and representational change in two-move matchstick tasks
Insight problems are problems where the problem solver struggles to find a solution until * aha! * the solution suddenly appears. Two contemporary theories suggest that insight problems are difficult either because problem solvers begin with an incorrect representation of the problem, or that problem solvers apply inappropriate heuristics to the problem. The relative contributions of representational change and inappropriate heuristics on the process of insight problem solving was studied with a task that required the problem solver to move two matchsticks in order to transform an incorrect arithmetic statement into a correct one. Problem solvers (N = 120) worked on two different types of two-move matchstick arithmetic problems that both varied with respect to the effectiveness of heuristics and to the degree of a necessary representational change of the problem representation. A strong influence of representational change on solution rates was found whereas the influence of heuristics had minimal effects on solution rates. That is, the difficulty of insight problems within the two-move matchstick arithmetic domain is governed by the degree of representational change required. A model is presented that details representational change as the necessary condition for ensuring that appropriate heuristics can be applied on the proper problem representation
A Formal Approach based on Fuzzy Logic for the Specification of Component-Based Interactive Systems
Formal methods are widely recognized as a powerful engineering method for the
specification, simulation, development, and verification of distributed
interactive systems. However, most formal methods rely on a two-valued logic,
and are therefore limited to the axioms of that logic: a specification is valid
or invalid, component behavior is realizable or not, safety properties hold or
are violated, systems are available or unavailable. Especially when the problem
domain entails uncertainty, impreciseness, and vagueness, the appliance of such
methods becomes a challenging task. In order to overcome the limitations
resulting from the strict modus operandi of formal methods, the main objective
of this work is to relax the boolean notion of formal specifications by using
fuzzy logic. The present approach is based on Focus theory, a model-based and
strictly formal method for componentbased interactive systems. The contribution
of this work is twofold: i) we introduce a specification technique based on
fuzzy logic which can be used on top of Focus to develop formal specifications
in a qualitative fashion; ii) we partially extend Focus theory to a fuzzy one
which allows the specification of fuzzy components and fuzzy interactions.
While the former provides a methodology for approximating I/O behaviors under
imprecision, the latter enables to capture a more quantitative view of
specification properties such as realizability.Comment: In Proceedings FESCA 2015, arXiv:1503.0437
Theory of excitation transfer between two-dimensional semiconductor and molecular layers
The geometry-dependent energy transfer rate from an electrically pumped
inorganic semiconductor quantum well into an organic molecular layer is studied
theoretically. We focus on F\"orster-type nonradiative excitation transfer
between the organic and inorganic layer and include quasi-momentum conservation
and intermolecular coupling between the molecules in the organic film.
(Transition) partial charges calculated from density-functional theory are used
to calculate the coupling elements. The partial charges describe the spatial
charge distribution and go beyond the common dipole-dipole interaction. We find
that the transfer rates are highly sensitive to variations in the geometry of
the hybrid inorganic/organic system. For instance, the transfer efficiency is
improved by orders of magnitude by tuning the relative orientation and
positioning of the molecules. Also, the operating regime is identified where
in-scattering dominates over unwanted back-scattering from the molecular layer
into the substrate
The Phenomenology of Glueball and Hybrid Mesons
The existence of non-q\bar{q} hadrons such as glueballs and hybrids is one of
the most important qualitative questions in QCD. The COMPASS experiment offers
the possibility to unambiguously identify such states and map out the glueball
and hybrid spectrum. In this review I discuss the expected properties of
glueballs and hybrids and how they might be produced and studied by the COMPASS
collaboration.Comment: Invited talk at the Workshop on Future Physics @ COMPASS, CERN, Sept
26-27 2002. 12 pages, 6 figures. Uses cernrep.cls (included
- …