Developing attribute acquisition strategies in spoken dialogue systems via user simulation

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (p. 159-169).A spoken dialogue system (SDS) is an application that supports conversational interaction with a human to perform some task. SDSs are emerging as an intuitive and efficient means for accessing information. A critical barrier to their widespread deployment remains in the form of communication breakdown at strategic points in the dialogue, often when the user tries to supply a named entity from a large or open vocabulary set. For example, a weather system might know several thousand cities, but there is no easy way to inform the user about what those cities are. The system will likely misrecognize any unknown city as some known city. The inability of a system to acquire an unknown value can lead to unpredictable behavior by the system, as well as by the user. This thesis presents a framework for developing attribute acquisition strategies with a simulated user. We specifically focus on the acquisition of unknown city names in a flight domain, through a spell-mode subdialogue. Collecting data from real users is costly in both time and resources. In addition, our goal is to focus on situations that tend to occur sporadically in real dialogues, depending on the domain and the user's experience in that domain.(cont.) Therefore, we chose to employ user simulation, which would allow us to generate a large number of dialogues, and to configure the input as desired in order to exercise specific strategies. We present a novel method of utterance generation for user simulation, that exploits an existing corpus of real user dialogues, but recombines the utterances using an example-based, template approach. Items of interest not in the corpus, such as foreign or unknown cities, can be included by splicing in synthesized speech. This method allows us to produce realistic utterances by retaining the structural variety of real user utterances, while introducing cities that can only be resolved via spelling. We also developed a model of generic dialogue management, allowing a developer to quickly specify interaction properties on a per-attribute basis. This model was used to assess the effectiveness of various combinations of dialogue strategies and simulated user behavior. Current approaches to user simulation typically model simulated utterances at the intention level, assuming perfect recognition and understanding. We employ speech to develop our strategies in the context of errors that occur naturally from recognition and understanding.(cont.) We use simulation to address two problems: the conflict problem requires the system to choose how to act when a new hypothesis for an attribute conflicts with its current belief, while the compliance problem requires the system to decide whether a user was compliant with a spelling request. Decision models were learned from simulated data, and were tested with real users, showing that the learned model significantly outperformed a heuristic model in choosing the "ideal" response to the conflict problem, with accuracies of 84.1% and 52.1%, respectively. The learned model to predict compliance achieved a respectable 96.3% accuracy. These results suggest that such models learned from simulated data can attain similar, if not better, performance in dialogues with real users.by Edward A. Filisko.Ph.D

Language technologies in speech-enabled second language learning games : from reading to dialogue

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 237-244).Second language learning has become an important societal need over the past decades. Given that the number of language teachers is far below demand, computer-aided language learning software is becoming a promising supplement to traditional classroom learning, as well as potentially enabling new opportunities for self-learning. The use of speech technologies is especially attractive to offer students unlimited chances for speaking exercises. To create helpful and intelligent speaking exercises on a computer, it is necessary for the computer to not only recognize the acoustics, but also to understand the meaning and give appropriate responses. Nevertheless, most existing speech-enabled language learning software focuses only on speech recognition and pronunciation training. Very few have emphasized exercising the student's composition and comprehension abilities and adopting language technologies to enable free-form conversation emulating a real human tutor. This thesis investigates the critical functionalities of a computer-aided language learning system, and presents a generic framework as well as various language- and domain-independent modules to enable building complex speech-based language learning systems. Four games have been designed and implemented using the framework and the modules to demonstrate their usability and flexibility, where dynamic content creation, automatic assessment, and automatic assistance are emphasized. The four games, reading, translation, question-answering and dialogue, offer different activities with gradually increasing difficulty, and involve a wide range of language processing techniques, such as language understanding, language generation, question generation, context resolution, dialogue management and user simulation. User studies with real subjects show that the systems were well received and judged to be helpful.by Yushi Xu.Ph.D

Toward Widely-Available and Usable Multimodal Conversational Interfaces

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 159-166).Multimodal conversational interfaces, which allow humans to interact with a computer using a combination of spoken natural language and a graphical interface, offer the potential to transform the manner by which humans communicate with computers. While researchers have developed myriad such interfaces, none have made the transition out of the laboratory and into the hands of a significant number of users. This thesis makes progress toward overcoming two intertwined barriers preventing more widespread adoption: availability and usability. Toward addressing the problem of availability, this thesis introduces a new platform for building multimodal interfaces that makes it easy to deploy them to users via the World Wide Web. One consequence of this work is City Browser, the first multimodal conversational interface made publicly available to anyone with a web browser and a microphone. City Browser serves as a proof-of-concept that significant amounts of usage data can be collected in this way, allowing a glimpse of how users interact with such interfaces outside of a laboratory environment. City Browser, in turn, has served as the primary platform for deploying and evaluating three new strategies aimed at improving usability. The most pressing usability challenge for conversational interfaces is their limited ability to accurately transcribe and understand spoken natural language. The three strategies developed in this thesis - context-sensitive language modeling, response confidence scoring, and user behavior shaping - each attack the problem from a different angle, but they are linked in that each critically integrates information from the conversational context.by Alexander Gruenstein.Ph.D

Experiments on Visual Acuity and the Visibility of Markings on the Ground in Long-duration Earth-Orbital Space Flight

Visual acuity and visibility of markings on ground in long duration earth orbital space fligh

The Goldstone solar system radar: A science instrument for planetary research

The Goldstone Solar System Radar (GSSR) station at NASA's Deep Space Communications Complex in California's Mojave Desert is described. A short chronological account of the GSSR's technical development and scientific discoveries is given. This is followed by a basic discussion of how information is derived from the radar echo and how the raw information can be used to increase understanding of the solar system. A moderately detailed description of the radar system is given, and the engineering performance of the radar is discussed. The operating characteristics of the Arcibo Observatory in Puerto Rico are briefly described and compared with those of the GSSR. Planned and in-process improvements to the existing radar, as well as the performance of a hypothetical 128-m diameter antenna radar station, are described. A comprehensive bibliography of referred scientific and engineering articles presenting results that depended on data gathered by the instrument is provided

Aeronautics and space report of the president, 1974 activities

The U.S. Government activities for 1974 in aeronautics and space are presented. Significant contributions toward the fulfillment of the nation's goals in space and aeronautics are covered, including application of space systems and technology to beneficial uses on earth, exploration of space and increase of scientific knowledge, development of improved space systems and technology, international cooperation, and advancement of civil and military aeronautics. Also in 1974, space activities in the private sector expanded to provide additional services to the public. The accomplishments are summarized

International Telemedicine/Disaster Medicine Conference: Papers and Presentations

The first International Telemedicine/Disaster Medicine Conference was held in Dec. 1991. The overall purpose was to convene an international, multidisciplinary gathering of experts to discuss the emerging field of telemedicine and assess its future directions; principally the application of space technology to disaster response and management, but also to clinical medicine, remote health care, public health, and other needs. This collection is intended to acquaint the reader with recent landmark efforts in telemedicine as applied to disaster management and remote health care, the technical requirements of telemedicine systems, the application of telemedicine and telehealth in the U.S. space program, and the social and humanitarian dimensions of this area of medicine

Stopover biology of migratory landbirds in a heavily urbanized landscape, the New York metropolitan area

Migration routes of many Nearctic-Neotropical landbirds pass through the most urbanized regions of North America. Migrants use urban habitat fragments as stopover sites and commonly occur in cities at exceptional density. Yet, knowledge of migrant stopover biology and refueling opportunities in such places is severely limited. This dissertation examined several aspects of migrant stopover biology in the New York metropolitan area to gain a more holistic understanding of how migratory landbirds utilize urban stopover sites, and ultimately to assess the quality of urban habitats as stopover sites. I first generated morphometric predictive models using salvaged bird specimens to allow me in subsequent studies to noninvasively measure the energetic condition (fat mass) of migrants in New York City (NYC). Next I compared the refueling performance of migrants in NYC to that of conspecifics in less-disturbed forests outside of the city. Blood plasma metabolite profiles indicated that refueling conditions for migrants were no poorer in NYC than in the non-urban habitats. Further, migrant refueling rates were comparable to, and in some cases higher than, those reported in the literature for birds at various non-urban stopover sites. Measures of arthropod biomass suggested food abundance for insectivorous migrants was also similar within and outside NYC. I then showed that stopover refueling in NYC often involved substantial increases in lean mass. This finding carries implications for stopover habitat management practices, as migrants using these sites will require high-protein foods in addition to the lipid- and carbohydrate-rich foods that maximize fattening rates. Next, radio-telemetry data from a small pilot study provided one of the first descriptions of migrant stopover durations within a city. Stopover durations ranged 1-14 days and were negatively related to fat mass, but not lean body mass, upon arrival. A larger-scale telemetry study revealed that migrant spatial behaviour in NYC was in many ways similar to what has been observed in passerine migrants in non-urban areas. Movement patterns were indicative of an ability to search for, locate, and occupy suitable microhabitat, and temporary home ranges suggested forest size was more than sufficient to meet their area requirements. Collectively, these studies provide a comprehensive assessment of the quality of urban habitats as migratory bird stopover sites. Findings indicated that the sites examined are functioning in the same fashion as less-disturbed, larger forest tracts elsewhere. No evidence was found to suggest that stopover refueling conditions within one of the world’s most urbanized landscapes are inadequate for migrating landbirds

Biotechnology

Biotechnological problems of man machine systems required for long duration space flight

Biomedical and Human Factors Requirements for a Manned Earth Orbiting Station

This report is the result of a study conducted by Republic Aviation Corporation in conjunction with Spacelabs, Inc.,in a team effort in which Republic Aviation Corporation was prime contractor. In order to determine the realistic engineering design requirements associated with the medical and human factors problems of a manned space station, an interdisciplinary team of personnel from the Research and Space Divisions was organized. This team included engineers, physicians, physiologists, psychologists, and physicists. Recognizing that the value of the study is dependent upon medical judgments as well as more quantifiable factors (such as design parameters) a group of highly qualified medical consultants participated in working sessions to determine which medical measurements are required to meet the objectives of the study. In addition, various Life Sciences personnel from NASA (Headquarters, Langley, MSC) participated in monthly review sessions. The organization, team members, consultants, and some of the part-time contributors are shown in Figure 1. This final report embodies contributions from all of these participants