Catálogo de publicaciones - libros

People with severe motor control problems, who at the same time lack of verbal communication, use alternatively non verbal communication techniques and aids which usually combine symbols, icons, drawings, sounds and text. The present paper describes completely configurable multilingual software that can contribute to the above group’s needs as it facilitates access to a personalized computerized system which provides options for non verbal-written communication. This system incorporates enhanced or new features like acronymic writing, single switch access, word and phrase prediction, keyboard layout configuration, scanning of word and phrase lists and makes communication through internet (email and chatting options) possible. More over the system records all keystrokes, all words and acronyms used and provides valuable data for research on the best possible configuration of the system. What makes the system more innovative is the possibility it provides to users to send their emails and to network through internet chatting, with others.

The use of animated talking agents is a novel feature of many multimodal spoken dialogue systems. The addition and integration of a virtual talking head has direct implications for the way in which users approach and interact with such systems. However, understanding the interactions between visual expressions, dialogue functions and the acoustics of the corresponding speech presents a substantial challenge. Some of the visual articulation is closely related to the speech acoustics, while there are other articulatory movements affecting speech acoustics that are not visible on the outside of the face. Many facial gestures used for communicative purposes do not affect the acoustics directly, but might nevertheless be connected on a higher communicative level in which the timing of the gestures could play an important role. This chapter looks into the communicative function of the animated talking agent, and its effect on intelligibility and the flow of the dialogue.

In the Sensitive Artificial Listener project research is performed with the aim to design an embodied agent that not only generates the appropriate nonverbal behaviors that accompany speech, but that also displays verbal and nonverbal behaviors during the production of speech by its conversational partner. Apart from many applications for embodied agents where natural interaction between agent and human partner also require this behavior, the results of this project are also meant to play a role in research on emotional behavior during conversations. In this paper, our research and implementation efforts in this project are discussed and illustrated with examples of experiments, research approaches and interfaces in development.

In this paper we emphasize the relevance of low-complexity algorithms for biometric recognition and we present to examples with special emphasis on face recognition. Our face recognition application has been implemented on a low-cost fixed point processor and we have evaluated that with 169 integer coefficients per face we achieve better identification results (92%) than the classical eigenfaces approach (86.5%), and close to the DCT (92.5%) with a reduced computational cost.

The communication itself is considered as a multimodal interactive process binding speech with other modalities. In this contribution some results of the project MobilTel (Mobile Multimodal Telecommunications System) are presented. It has provided a research framework resulting in a develop-ment of mobile terminal (PDA) based multimodal interface, enabling user to obtain information from internet by multimodal way through wireless telecommunication network. The MobilTel communicator is a speech centric multimodal system with speech interaction capabilities in Slovak language supplemented with graphical modalities. The graphical modalities are pen – touch screen interaction, keyboard, and display on which the information is more user friendly presented, and provides hyperlink and scrolling menu availability. The architecture of the MobilTel communicator and methods of interaction between PDA and MobilTel communicator are described. The graphical examples of services that enable users to obtain information about weather or information about train connection are also presented.

Embodied conversational agents employed in multimodal interaction applications have the potential to achieve similar properties as humans in face-to-face conversation. They enable the inclusion of verbal and nonverbal communication. Thus, the degree of personalization of the user interface is much higher than in other human-computer interfaces. This, of course, greatly contributes to the naturalness and user friendliness of the interface, opening-up a wide area of possible applications. Two implementations of embodied conversational agents in human-computer interaction are presented in this paper: the first one in a Wizard-of-Oz application and the second in a dialogue system. In the Wizard-of-Oz application, the embodied conversational agent is applied in a way that it conveys the spoken information of the operator to the user with whom the operator communicates. Depending on the scenario of the application, the user may or not be aware of the operator’s involvement. The operator can communicate with the user based on audio/visual, or only audio, communication. This paper describes an application setup, which enables distant communication with the user, where the user is unaware of the operator’s involvement. A real-time viseme recognizer is needed to ensure a proper response from the agent. In addition, implementation of the embodied conversational agent Lili hosting an entertainment show, which is broadcast by RTV Slovenia, will be described in more detail. Employment of the embodied conversational agent as a virtual major-domo named Maja, within an intelligent ambience, using speech recognition system and TTS system PLATTOS, will be also described.

Can we create a virtual storyteller that is expressive enough to convey in a natural way a story to an audience? What are the most important features for creating such character? This paper presents a study where the influence of different modalities in the perception of a story told by both a synthetic storyteller and a real one are analyzed. In order to evaluate it, three modes of communication were taken into account: voice, facial expression and gestures. One hundred and eight students from computer science watched a video where a storyteller narrated the traditional Portuguese story entitled ”O Coelhinho Branco” (The little white rabbit). The students were divided into four groups. Each of these groups saw one video where the storyteller was portrayed either by a synthetic character or a human. The storyteller’s voice, no matter the nature of the character, could also be real or synthetic. After the video display, the participants filled a questionnaire where they rated the storyteller’s performance. Although the synthetic versions used in the experiment obtained lower classifications than their natural counterparts, the data suggests that the gap between synthetic and real gestures is the smallest while the synthetic voice is the furthest from its natural version. Furthermore, when we used the synthetic voice, the facial expressions of both characters (the virtual and the real) were rated worse than with the real voice. This effect was not significant for the gestures, thus suggesting that the importance of building synthetic voices as natural as possible is extremely important as it impacts in the perception of other means of communication (such as the perception of the facial expression).