Global Ambiguity Research Articles

PP-Attachment Disambiguation for Swedish: Combining Unsupervised and Supervised Training Data

Structural ambiguity, particularly attachment of prepositional phrases, is a serious type of global ambiguity in Natural Language. The disambiguation becomes crucial when a syntactic analyzer must make the correct decision among at least two equally grammatical parse-trees for the same sentence. This paper attempts to find answers to the problem of how attachment ambiguity can be resolved by utilizing Machine Learning (ML) techniques. ML is founded on the assumption that the performance in cognitive tasks is based on the similarity of new situations (testing) to stored representations of earlier experiences (training). Therefore, a large amount of training data is an important prerequisite for providing a solution to the problem. A combination of unsupervised and restricted supervised acquisition of such data will be reported. Training is performed both on a subset of the content of the Gothenburg Lexical Database (GLDB), and on instances of large corpora annotated with coarse-grained semantic information. Testing is performed on corpora instances using a range of different algorithms and metrics. The application language is written Swedish.

Corrections to "Symbolic Analysis of Large Analog Integrated Circuits: The Numerical Reference Generation Problem"

group. In the phase of fault location, a solution giving as faulty a component of the testable group uniquely locates the fault, while a solution giving as faulty one of the components of the two global ambiguity groups indicates only that there is a fault in that group, without allowing the determination of the effectively faulty component. It is worth noting that these results are theoretical and do not take into account practical aspects (measurement errors, component tolerances, etc.). However, they give rigorous limits to the solvability of the fault diagnosis problem and can be considered as an index of efficiency for the used method of fault location. From this point of view, it seems that the results obtained in the above paper could be further improved. In fact, such results allow only to locate a fault between two global ambiguity groups, considering only signed variations of the components (increment or decrement). It is our opinion that the quality of the results obtained by the presented method can be improved exploiting the information given by algorithms for testability and canonical ambiguity group determination. In particular, this information should be taken into account as a preprocessing step in the selection of the ambiguity groups used for neural network training. The measure could be successively considered for a practical verification of the obtained theoretical ambiguity groups. It is worth pointing out that the more recent algorithms for testability computation, based on the symbolic approach [9]‐[11], have a low computational complexity. Hence, the introduction of the testability evaluation phase in the proposed procedure will little increase the computational cost. III. CONCLUSION The method of linear circuit fault diagnosis proposed by Spina and Upadhyaya in this paper presents some interesting aspects as the use of a white noise generator with an artificial neural network. It would be very interesting to further enhance the method by considering the information given by testability and ambiguity groups, achievable with well-known algorithms developed in the last 20 years.

Quantum cosmology and physics of transitions with a change of the spacetime signature

This paper examines elements of the general theory of transitions with changing spacetime signature in quantum gravity and cosmology as suggested in a pioneer work of A D Sakharov. Unlike the conventional formal method for functional integration, this approach uses as the starting point the Dirac–Wheeler–de Witt operator quantization and its reduction to quantization in Arnowitt–Deser–Misner variables. It has been demonstrated that motivation to consider Euclidean–Lorentzian transitions consists in global ambiguity of physical reduction on the phase space of the theory (a gravitational analog of the problem of Gribov's copies). This ambiguity in particular results in the indefinite sign of the physical inner product of quantum states and leads to the concept of third quantization. An alternative approach is quantization in the York gauge and in special variables of conformal superspace. This quantization is likely to provide a global solution of the ambiguity problem, but the problems of Euclidean–Lorentzian transitions arise in this formalism in the language of complexification of a conformal space of the Wick-rotation type for the time variable in the Klein–Gordon equation. The problem of origin of the early Universe via gravitational tunneling in Hartle–Hawking and Vilenkin quantum states is considered to illustrate applications of the general theory. The mechanism is described by which loop effects generate the normalizable distribution function for the ensemble of chaotic inflationary universes. In a model with a large non-minimal coupling constant for the scalar inflation, this mechanism gives rise to a sharp probability peak at sub-Planckian values for the Hubble constant which is in good agreement with the contemporary observational status of the cosmological inflation theory.

Three-loop vanishing of the superstring cosmological constant

We employ a holomorphic unitary gauge to evaluate the genus-three partition function for closed superstrings in ten-dimensional flat space in the picture-changing representation. The Riemann identity leads to a pointwise vanishing measure in moduli space which trivially avoids global ambiguities.

Computing the velocity field along contours (abstract only)

In this paper, we present a computational study of the measurement of motion. Similar to other visual processes, the motion of elements is not determined uniquely by information in the changing image; additional constraint is required to compute a unique velocity field. Given this global ambiguity of motion, local measurements from the changing image cannot possibly specify a unique local velocity vector, and in fact, may only specify one component of velocity. Computation of the full two-dimensional velocity field generally requires the integration of local motion measurements, either over an area, or along contours in the image. We examine the integration of local motion measurements along contours, using an additional constraint of smoothness of the velocity field. The predictions of an algorithm based on this constraint are compared with human motion perception on a few demonstrations.

RELATIONSHIPS BETWEEN RESPONSE STABILITY AND ITEM ENDORSEMENT, SOCIAL DESIRABILITY, AND AMBIGUITY IN THE MMPI AND THE CPI.

Relationships between two indices of response stability and item endorsement, social desirability, and seven ambiguity indices were investigated separately within the MMPI, the unique items of the CPI, and two subpools moderate in endorsement and social desirability. Within the two original pools, zero-order correlations and multiple regression analyses revealed that only extremeness of endorsement and social desirability were substantially related to response stability; within the moderate subpools, however, indices of ambiguity-especially item length and ratings of global ambiguity, behavioral reference, and estimated stability-accounted for important degrees of variance individually as well as in combination. Reasons for the moderating effects of endorsement and social desirability are discussed, as are the implications for scale construction.