Multimodal person recognition for human-vehicle interaction

Next-generation vehicles will undoubtedly feature biometric person recognition as part of an effort to improve the driving experience. Today's technology prevents such systems from operating satisfactorily under adverse conditions. A proposed framework for achieving person recognition successfully combines different biometric modalities, borne out in two case studies

Improving the Parallel Execution of Behavior Trees

Behavior Trees (BTs) have become a popular framework for designing controllers of autonomous agents in the computer game and in the robotics industry. One of the key advantages of BTs lies in their modularity, where independent modules can be composed to create more complex ones. In the classical formulation of BTs, modules can be composed using one of the three operators: Sequence, Fallback, and Parallel. The Parallel operator is rarely used despite its strong potential against other control architectures as Finite State Machines. This is due to the fact that concurrent actions may lead to unexpected problems similar to the ones experienced in concurrent programming. In this paper, we introduce Concurrent BTs (CBTs) as a generalization of BTs in which we introduce the notions of progress and resource usage. We show how CBTs allow safe concurrent executions of actions and we analyze the approach from a mathematical standpoint. To illustrate the use of CBTs, we provide a set of use cases in robotics scenarios

A Study of Natural Language Phonetic Symbolism

The present investigation concerns itself with the phenomenon of natural language phonetic symbolism. Proponents of phonetic symbolism, or the hypothesis of phonetic universals, as it is sometimes called, claim that human speech sounds have inherent meaning apart from their learned association with referents in the world. Since phonetic symbolism had been used to explain both success in guessing the meanings of foreign words and also a consistent tendency to attribute particular meanings to selected nonlinguistic verbalizations, it was hypothesized that phonetic symbols were part of an underlying stratum of semantic invariance. Further, it was assumed that such phonetic/semantic symbols should demonstrate their innate and a priori character by being most readily accessible through mental processes that are global, affective and pre-logical. Consequently, it was decided to employ two research strategies which had yielded promising results in an earlier study which examined a related archaic linguistic phenomenon (Adair 1975). The first of these strategies makes use of the Jungian typological notion that persons characterized as high in intuition tend to gather data from inner mental processes for the conduct of their daily lives. Because of this tendency toward inner consultation, it was predicted that high intuiting persons should excel in decoding phonetic/semantic units that can be found as archaic, pre-logical deposits in all languages. Lesser performance was expected from persons who are nonintuitors, since such individuals are assumed to use data from immediate sensory experience rather than from inner rumination. Subjects were selected to represent both extremes of this Jungian sensation—intuition dimension on the basis of their performance on the Myers-Briggs Type Indicator (1962). The other research strategy for discriminating logical from pre- logical, intuitive processing involved making use of the fact that mon- aurally presented stimuli are differentially routed to the cerebral hemispheres. The opposite-side hemisphere processes the majority of the sound input to an ear. Since the right hemisphere has come to be associated with intuitive, aesthetic and global cognition, it was thought that stimulus material (i.e., foreign words) presented to this hemisphere via the opposite ear would elicit more archaic responses, which would have relatively higher congruence with the a priori semantic structure in foreign language words. It was also hypothesized that foreign words presented monaurally to the left hemisphere would elicit responses relatively less congruent with phonetic/semantic a prioris, since this hemisphere specializes in linear, logical and analytic processing. Monaural presentation of foreign word stimuli was accomplished by blocking one earphone of a headset with acoustically dense material. Response choices were presented to subjects in booklets which contained four options per stimulus. These options were arranged such that two orthogonal polar opposite pairs would be presented in each option set. Randomization of order effects for response choices was achieved through application of an incomplete latin square method. Although the data failed to support the hypotheses outlined above, a trend was noted for the intuition—sensation dimension. These results are discussed with respect to sex differences in the degree of hemisphere specialization and ineffectiveness of the dependent variable measure

The Effect of Developmental Factors on the Use of an Electronic Communication Device.

This study addressed a poorly understood variable of voice output communication aid (VOCA) use, namely mnemonic development. Forty children without disabilities, aged from 49 to 60 months, were required to use an IntroTalker (Prentke Romich Company) to participate in a one-on-one storybook reading task with the investigator. They were provided with sixteen messages to use during a scripted reading of The Three Bears. Children could use a trained verbal elaboration strategy or generate their own methods to retrieve messages. Immediate and delayed responses of children under two training methods were compared, and the contribution of developmental factors, including metamemory, were evaluated. In the control method, Direct Instruction (DI), children learned to retrieve messages via an error-free method including simple repetition of a verbal elaboration mnemonic. In the experimental method, Active Problem Solving (APS), children were first led through a series of steps alerting them to the limitations of non-symbolic retrieval strategies and allowing them to make retrieval errors, thus discovered the relative value of various retrieval strategies. Next, they were taught to retrieve the remaining messages in the same way as the DI children. Children with low metamemory skill were less accurate in their retrieval of messages, and produced more Self-corrected Responses when trained under the APS condition. Children receiving APS training showed an initial retrieval advantage on the first story-retelling immediately following training; however, on the second day retrieval by DI subjects matched APS. It was concluded that DI children experienced a de facto active problem-solving condition on the first day, when they produced many errors, thereby enhancing the value of the verbal elaborations they had been trained to use. Effects of perceptual, semantic and syntactic development, and of conflicts between the canonical and experimental Three Bears script were evident. Although the use of a normally developing population is controversial in the area of augmentative communication, the strategy was found to produce valuable insights into the errors made by children. Overall, the task was easy for most of the children, thereby supporting the use of VOCAs with young children

A Neurocomputational Model of Grounded Language Comprehension and Production at the Sentence Level

While symbolic and statistical approaches to natural language processing have become undeniably impressive in recent years, such systems still display a tendency to make errors that are inscrutable to human onlookers. This disconnect with human processing may stem from the vast differences in the substrates that underly natural language processing in artificial systems versus biological systems. To create a more relatable system, this dissertation turns to the more biologically inspired substrate of neural networks, describing the design and implementation of a model that learns to comprehend and produce language at the sentence level. The model's task is to ground simulated speech streams, representing a simple subset of English, in terms of a virtual environment. The model learns to understand and answer full-sentence questions about the environment by mimicking the speech stream of another speaker, much as a human language learner would. It is the only known neural model to date that can learn to map natural language questions to full-sentence natural language answers, where both question and answer are represented sublexically as phoneme sequences. The model addresses important points for which most other models, neural and otherwise, fail to account. First, the model learns to ground its linguistic knowledge using human-like sensory representations, gaining language understanding at a deeper level than that of syntactic structure. Second, analysis provides evidence that the model learns combinatorial internal representations, thus gaining the compositionality of symbolic approaches to cognition, which is vital for computationally efficient encoding and decoding of meaning. The model does this while retaining the fully distributed representations characteristic of neural networks, providing the resistance to damage and graceful degradation that are generally lacking in symbolic and statistical approaches. Finally, the model learns via direct imitation of another speaker, allowing it to emulate human processing with greater fidelity, thus increasing the relatability of its behavior. Along the way, this dissertation develops a novel training algorithm that, for the first time, requires only local computations to train arbitrary second-order recurrent neural networks. This algorithm is evaluated on its overall efficacy, biological feasibility, and ability to reproduce peculiarities of human learning such as age-correlated effects in second language acquisition

Directional adposition use in English, Swedish and Finnish

Directional adpositions such as to the left of describe where a Figure is in relation to a Ground. English and Swedish directional adpositions refer to the location of a Figure in relation to a Ground, whether both are static or in motion. In contrast, the Finnish directional adpositions edellä (in front of) and jäljessä (behind) solely describe the location of a moving Figure in relation to a moving Ground (Nikanne, 2003). When using directional adpositions, a frame of reference must be assumed for interpreting the meaning of directional adpositions. For example, the meaning of to the left of in English can be based on a relative (speaker or listener based) reference frame or an intrinsic (object based) reference frame (Levinson, 1996). When a Figure and a Ground are both in motion, it is possible for a Figure to be described as being behind or in front of the Ground, even if neither have intrinsic features. As shown by Walker (in preparation), there are good reasons to assume that in the latter case a motion based reference frame is involved. This means that if Finnish speakers would use edellä (in front of) and jäljessä (behind) more frequently in situations where both the Figure and Ground are in motion, a difference in reference frame use between Finnish on one hand and English and Swedish on the other could be expected. We asked native English, Swedish and Finnish speakers’ to select adpositions from a language specific list to describe the location of a Figure relative to a Ground when both were shown to be moving on a computer screen. We were interested in any differences between Finnish, English and Swedish speakers. All languages showed a predominant use of directional spatial adpositions referring to the lexical concepts TO THE LEFT OF, TO THE RIGHT OF, ABOVE and BELOW. There were no differences between the languages in directional adpositions use or reference frame use, including reference frame use based on motion. We conclude that despite differences in the grammars of the languages involved, and potential differences in reference frame system use, the three languages investigated encode Figure location in relation to Ground location in a similar way when both are in motion. Levinson, S. C. (1996). Frames of reference and Molyneux’s question: Crosslingiuistic evidence. In P. Bloom, M.A. Peterson, L. Nadel & M.F. Garrett (Eds.) Language and Space (pp.109-170). Massachusetts: MIT Press. Nikanne, U. (2003). How Finnish postpositions see the axis system. In E. van der Zee & J. Slack (Eds.), Representing direction in language and space. Oxford, UK: Oxford University Press. Walker, C. (in preparation). Motion encoding in language, the use of spatial locatives in a motion context. Unpublished doctoral dissertation, University of Lincoln, Lincoln. United Kingdo