Search results for "ambiguity"
showing 10 items of 105 documents
Syntax Error Handling
1990
In the previous chapters we have seen that the various parsers discussed, at least whenever they are deterministic, detect an error in any nonsentence. This means, that on any nonsentence there is a computation ending with an error configuration. For practical parsers, mere error detection is not enough; the parser should also emit a meaningful error message and recover from the error. A recovery means that the error configuration is transformed into a non-error configuration at which normal parsing can be resumed. Moreover, the transformation should be done so that as few input symbols as possible will be discarded. The goal of the error recovery is to maximize the amount of input text tha…
Ambiguity function analysis of pulse train propagation: applications to temporal Lau filtering
2007
We use the periodic-signal ambiguity function for visualizing the intensity-spectrum evolution through propagation in a first-order dispersive medium. We show that the degree of temporal coherence of the optical source plays the role of a low-pass filter on the signal's ambiguity function. Based on this, we present a condition on the temporal Lau effect for filtering harmonics at fractions of the Talbot length. This result allows one to increase the repetition rate of a pulse train obtained from a sinusoidally phase-modulated CW signal.
Towards an understanding of discrete ambiguities in truncated partial wave analyses
2017
It is well known that the observables in a single-channel scattering problem remain invariant once the amplitude is multiplied by an overall energy- and angle-dependent phase. This invariance is called the continuum ambiguity and acts on the infinite partial wave set. It has also long been known that, in the case of a truncated partial wave set, another invariance exists, originating from the replacement of the roots of partial wave amplitudes with their complex conjugate values. This discrete ambiguity is also known as the Omelaenko-Gersten-type ambiguity. In this paper, we show that for scalar particles, discrete ambiguities are just a subset of continuum ambiguities with a specific phase…
On the ambiguities of sign determination of the S-matrix from energy levels in a finite box
2013
In a recent paper the authors make a study on the determination of the S-matrix elements for scattering of particles in the infinite volume from the energy levels in a finite box for the case of multiple channels. The study is done with a toy model in 1+1 dimension and the authors find that there is some ambiguity in the sign of nondiagonal matrix elements, casting doubts on whether the needed observables in the infinite volume can be obtained from the energy levels of the box. In this paper I present an easy derivation, confirming the ambiguity of the sign and argue that this, however, does not put restrictions in the determination of observables.
Shape from polarization: a method for solving zenithal angle ambiguity
2012
International audience; We report a multispectral based method that permits the evolution of shape from polarization setup applied to 3D shape estimation of transparent objects. The setup is based on a polarization imaging technique which is a recent imaging method based on the analysis of the polarization state of the light in the observed scene. The technique has rapidly evolved with the development of electro-optic components and some polarization cameras are now available on the market. Shape from polarization consists in measuring the azimuthal and zenithal angles characterizing the normal of each point of the observed surface. We focus on the ambiguity in the measurement of the zenith…
Productive Ambiguity in Mathematics
2011
According to E. Grosholz, there is a phenomenon called `productive ambiguity' which plays a very important role in mathematics, and the sciences, because it is instrumental to the resolution of many open questions. The main task of this paper is that of assessing Grosholz's claim with regard to mathematics.
Relationships between Domain-Specific Knowledge, Generic Attributes, and Instructional Skills
2020
We introduce a theoretical framework on teachers’ instructional skills to describe how they can be modeled across different domains. This framework conceptualizes teachers’ instructional skills as action-related skills (during instruction) and reflective skills (before and after instruction), which are considered crucial for coping with the practical demands of everyday teaching in a specific subject. The theoretical framework assumes that both skill facets are influenced by the teacher’s professional knowledge, generic attributes such as general cognitive abilities or ambiguity tolerance as well as affective and motivational factors. To investigate the relationships between teachers’ instr…
Fractional Laplacians in bounded domains: Killed, reflected, censored, and taboo Lévy flights.
2018
The fractional Laplacian $(- \Delta)^{\alpha /2}$, $\alpha \in (0,2)$ has many equivalent (albeit formally different) realizations as a nonlocal generator of a family of $\alpha $-stable stochastic processes in $R^n$. On the other hand, if the process is to be restricted to a bounded domain, there are many inequivalent proposals for what a boundary-data respecting fractional Laplacian should actually be. This ambiguity holds true not only for each specific choice of the process behavior at the boundary (like e.g. absorbtion, reflection, conditioning or boundary taboos), but extends as well to its particular technical implementation (Dirchlet, Neumann, etc. problems). The inferred jump-type …
Cognitive processes related to problematic pornography use (PPU): A systematic review of experimental studies
2021
Highlights • Some people experience symptoms derived from pornography viewing. • Cognitive processes may be related to the development of Problematic Pornography Use (PPU). • We performed a systematic review of 21 studies exploring cognitive processes related to PPU. • We identified 4 cognitive processes relevant for the development and maintenance of PPU.
A Cognitive-based scheme for user reliability and expertise assessment in Q&A social networks
2011
Q&A social media has gained a great deal of attention during recent years. People rely on these sites to obtain information due to the number of advantages they offer as compared to conventional sources of knowledge (e.g., asynchronous and convenient access). However, for the same question one may find highly contradictory answers, causing ambiguity with respect to the correct information. This can be attributed to the presence of unreliable and/or non-expert users. In this work, we propose a novel approach for estimating the reliability and expertise of a user based on human cognitive traits. Every user can individually estimate these values based on local pairwise interactions. We examine…