Robust Parsing of Spoken Dialogue Using Contextual Knowledge and Recognition Probabilities

In this paper we describe the linguistic processor of a spoken dialogue system. The parser receives a word graph from the recognition module as its input. Its task is to find the best path through the graph. If no complete solution can be found, a robust mechanism for selecting multiple partial results is applied. We show how the information content rate of the results can be improved if the selection is based on an integrated quality score combining word recognition scores and context-dependent semantic predictions. Results of parsing word graphs with and without predictions are reported.Comment: 4 pages, LaTex source, 3 PostScript figures, uses epsf.sty and ETRW.sty, to appear in Proceedings of ESCA Workshop on Spoken Dialogue Systems, Denmark, May 30-June

Combining Expression and Content in Domains for Dialog Managers

We present work in progress on abstracting dialog managers from their domain in order to implement a dialog manager development tool which takes (among other data) a domain description as input and delivers a new dialog manager for the described domain as output. Thereby we will focus on two topics; firstly, the construction of domain descriptions with description logics and secondly, the interpretation of utterances in a given domain.Comment: 5 pages, uses conference.st

Modelling Users, Intentions, and Structure in Spoken Dialog

We outline how utterances in dialogs can be interpreted using a partial first order logic. We exploit the capability of this logic to talk about the truth status of formulae to define a notion of coherence between utterances and explain how this coherence relation can serve for the construction of AND/OR trees that represent the segmentation of the dialog. In a BDI model we formalize basic assumptions about dialog and cooperative behaviour of participants. These assumptions provide a basis for inferring speech acts from coherence relations between utterances and attitudes of dialog participants. Speech acts prove to be useful for determining dialog segments defined on the notion of completing expectations of dialog participants. Finally, we sketch how explicit segmentation signalled by cue phrases and performatives is covered by our dialog model.Comment: 17 page

Physiology of Nitrogen Fixation by a Species of Achromobacter

The metabolic pathway by which certain microorganisms incorporate atmospheric nitrogen into their protoplasm is at the present time unknown. In an attempt to determine this pathway scientists are studying the physiology of various nitrogen fixing bacteria and are within reasonable limits extrapolating this information from one organism to another. Thus far they have found certain physiological characteristics which appear to be common to all nitrogen fixing bacteria. Several years ago a species of the genus Achromobacter was isolated and shown to fix atmospheric nitrogen. Thus far very little has been published concerning the physiology of nitrogen fixation by this organism. This study was carried out in an attempt to confirm some of the reported findings regarding the physiology of nitrogen fixation by this organism and to determine other physiological characteristics which may be of value in the elucidation of the mechanisms of biological nitrogen fixation. The organism used for this study was a nitrogen fixing species of the genus Achromobacter. This organism, referred to as strain N4, was isolated from a Danish water course and was shown to fix nitrogen by Vagn Jensen. It as yet bears no species name. Its physiological characteristics are described by Jensen. At the beginning of this study physiological tests were made to confirm the identity and purity of the culture, which was carried on nutrient agar containing 0.2 per cent yeast extract. Because of the fact that growth in most experiments took place under anaerobic conditions in a medium which was essentially free of combined nitrogen the problem of contamination was not great. Periodic checks were made, however, to detect possible contamination by A. acrogenes. This was done by inoculating from experimental cultures into tubes of lactose broth containing gas tubes. Preliminary experiments were carried out using the modification described by Pengra and Wilson of a medium proposed by Monad and Wollman for the cultivation of Escherichia coli. Results of these experiments indicated that Achromobacter N4 produces relatively large quantities of acid during its gasless fermentation of carbohydrate

Hybrid Optimization Schemes for Quantum Control

Optimal control theory is a powerful tool for solving control problems in quantum mechanics, ranging from the control of chemical reactions to the implementation of gates in a quantum computer. Gradient-based optimization methods are able to find high fidelity controls, but require considerable numerical effort and often yield highly complex solutions. We propose here to employ a two-stage optimization scheme to significantly speed up convergence and achieve simpler controls. The control is initially parametrized using only a few free parameters, such that optimization in this pruned search space can be performed with a simplex method. The result, considered now simply as an arbitrary function on a time grid, is the starting point for further optimization with a gradient-based method that can quickly converge to high fidelities. We illustrate the success of this hybrid technique by optimizing a holonomic phasegate for two superconducting transmon qubits coupled with a shared transmission line resonator, showing that a combination of Nelder-Mead simplex and Krotov's method yields considerably better results than either one of the two methods alone.Comment: 17 pages, 5 figures, 2 table

Towards Understanding Spontaneous Speech: Word Accuracy vs. Concept Accuracy

In this paper we describe an approach to automatic evaluation of both the speech recognition and understanding capabilities of a spoken dialogue system for train time table information. We use word accuracy for recognition and concept accuracy for understanding performance judgement. Both measures are calculated by comparing these modules' output with a correct reference answer. We report evaluation results for a spontaneous speech corpus with about 10000 utterances. We observed a nearly linear relationship between word accuracy and concept accuracy.Comment: 4 pages PS, Latex2e source importing 2 eps figures, uses icslp.cls, caption.sty, psfig.sty; to appear in the Proceedings of the Fourth International Conference on Spoken Language Processing (ICSLP 96

Adaptation of NLP Techniques to Cultural Heritage Research and Documentation

The WissKI system provides a framework for ontology based science communication and cultural heritage documentation. In many cases, the documentation consists of semi-structured data records with free text fields. Most references in the texts comprise of person and place names, as well as time specifications. We present the WissKI tools for semantic annotation using controlled vocabularies and formal ontologies derived from CIDOC Conceptual Reference Model (CRM). Current research deals with the annotations as building blocks for event recognition. Finally, we outline how the CRM helps to build bridges between documentation in different scientific disciplines

Charting the circuit QED design landscape using optimal control theory

With recent improvements in coherence times, superconducting transmon qubits have become a promising platform for quantum computing. They can be flexibly engineered over a wide range of parameters, but also require us to identify an efficient operating regime. Using state-of-the-art quantum optimal control techniques, we exhaustively explore the landscape for creation and removal of entanglement over a wide range of design parameters. We identify an optimal operating region outside of the usually considered strongly dispersive regime, where multiple sources of entanglement interfere simultaneously, which we name the quasi-dispersive straddling qutrits (QuaDiSQ) regime. At a chosen point in this region, a universal gate set is realized by applying microwave fields for gate durations of 50 ns, with errors approaching the limit of intrinsic transmon coherence. Our systematic quantum optimal control approach is easily adapted to explore the parameter landscape of other quantum technology platforms.Comment: 13 pages, 5 figures, 2 pages supplementary, 1 supplementary figur