Existing vision substitute systems have insufficient spatial resolution to provide environmental information. To present detailed spatial information, we propose two stimulation methods to enhance transfer information using a 2-D tactile stimulator array. First, stimulators are divided into several groups. Since each stimulator group is activated alternately, the interval of stimulations can be shortened to less than the two-point discrimination threshold. In the case that stimulators are divided into two and four groups, the number of stimulators increases to twice and four times, respectively, that in the case of the two-point discrimination threshold. Further, a user selects the measurement range and the system presents targets within the range. The user acquires spatial information of the entire measurement area by changing the measurement range. This method can accurately present a range of targets. We examine and confirm these methods experimentally.

In this study, we achieved predictable control of a wheelchair by changing the existing mapping method of the joystick, which considers the consecutive operations of a motor of a wheelchair, to a new mapping method that corresponds to the internal model of a human being. Since the existing method uses the polar coordinate system, it is not easy at all to use this method to predict either the direction of motion or the operating order for changing the position of the wheelchair according to the requirements of an operator. In order to improve the embodiment, we divided the existing joystick mapping method into two degrees of freedom-one in the vertical axis that can control the velocity and the other, in the horizontal axis for direction control. Based on this division, we implemented a wheelchair model that can be controlled by the electromyography (EMG) signal from the neck and the arm muscles of an operator. This was achieved by mapping the divided degrees of freedom onto the degrees of freedom of the neck and arm of the operator. In this case, since the operator controls the direction of motion by the joint of his/her neck, he/she can move the wheelchair in the desired direction; thus, a more intuitive human interface is implemented.

To develop human interfaces such as home information equipment, highly capable word learning ability is required. In particular, in order to realize user-customized and situation-dependent interaction using language, a function is needed that can build new categories online in response to presented objects for an advanced human interface. However, at present, there are few basic studies focusing on the purpose of language acquisition with category formation. In this study, taking hints from an analogy between machine learning and infant developmental word acquisition, we propose a taxonomy-based word-learning model using a neural network. Through computer simulations, we show that our model can build categories and find the name of an object based on categorization.

Faces of a person performing freely in front of the camera can be captured in a sufficient resolution for facial parts recognition by the proposed camera system enhanced with a special PTZ camera. Head region, facial parts regions such as eyes and mouth and the borders of facial parts are extracted hierarchically by being guided by the irises and nostrils preliminarily extracted from the images of PTZ camera. In order to show the effectivity of this system, we proposed a possibility to generate the borders of facial parts of the face for the facial caricaturing and to introduce eye-contacting facial images which can eye-contact bilaterally with each other on the TV conference environment.

In this paper we propose a method to aid a visually impaired person in the operation of a computer running a graphical user interface (GUI). It is based on image processing techniques, using images taken by a color camera placed over a Braille display. The shape of the user's hand is extracted from the image by analyzing the hue and saturation histograms. The orientation of the hand, given by an angle θ with the vertical axis, is calculated based on central moments. The image of the hand is then rotated to a normalized position. The number of pixels in each column of the normalized image is counted, and the result is put in a histogram. By analyzing the coefficient of asymmetry of this histogram, it can be determined whether the thumb is positioned along the pointing finger, or whether it is far from the other fingers. These two positions define two states that correspond to a mouse button up or down. In this way, by rotating the hand and moving the thumb, we can emulate the acts of moving a scroll bar and depressing a mouse button, respectively. These operations can be used to perform tasks in a GUI, such as cut-and-paste, for example. Experimental results show that this method is fast and efficient for the proposed application.

This paper presents a vision-based human interface system that enables a user to move a target object in a 3D CG world by moving his hand. The system can interpret hand motions both in a frame fixed in the world and a frame attached to the user. If the latter is chosen, the user can move the object forward by moving his hand forward even if he has changed his body position. In addition, the user does not have to keep in mind that his hand is in the camera field of view. The active camera system tracks the user to keep him in its field of view. Moreover, the system does not need any camera calibration. The key for the realization of the system with such features is vision algorithms based on the multiple view affine invariance theory. We demon-strate an experimental system as well as the vision algorithms. Human operation experiments show the usefulness of the system.

This paper discusses a coding-based selection approach to a communication aid for the severely motor disabled. Several approaches including row-column scanning are briefly described, then we propose a new selection scheme based on the theory of adaptive coding. They are compared each other with respect to average switch activations in generating some text samples.

Password checking schemes are human identification methods commonly adopted in many information systems. One of their disadvantages is that an attacker who correctly observed an input password can impersonate the corresponding user freely. To overcome it there have been proposed interactive human identification schemes. Namely, a human prover who has a secret key is asked a question by a machine verifier, who then checks if an answer from the prover matches the question with respect to the key. This letter examines such a scheme that requires relatively less efforts to human provers. By computer experiments this letter evaluates its resistance against a type of attack; after observing several pairs of questions and correct answers how successfully can an attacker answer the next question?

We are studying a novel concept of the on-line hospital system using a virtual environment called Hyper Hospital," the Hyper Hospital" is a medical care system which is constructed in a distributed manner to the electronic information network using virtual reality (VR) as a human interface. In the present report, we studied the physiological and psychological responses of healthy subjects induced by the usage of the VR in terms of fatigue. Twenty healthy young male subjects were exposed to the virtual reality system and they performed some psychological tasks with a virtual nurse for 30 minutes. Several parameters of physiological, psychological, and subjective fatigue were measured. None of the physiological or psychological parameters such as urinary catecholamine release, ECG, etc. showed significant fatigue induced by our VR system. However, by using a standard questionnaire, some kinds of subjective fatigue were noted and they were thought to be indicating a direction of improvement for our VR system.

The Hyper Hospital" is a novel medical care system which will be constructed on an electronic information network. The human interface of the Hyper Hospital based on the modern virtual reality technology is expected to enhance patients' ability to heal by providing computer-supported on-line visual consultations. In order to investigate the effects and features of on-line visual consultations in the Hyper Hospital, we conducted an experiment to clarify the influence of electronic interviews on the talking behavior of interviewees in the context of simulated doctor-patient interactions. Four types of distant-confrontation interviews were made with voluntary subjects and their verbal and non-verbal responses were analyzed from the behavioral point of view. The types of interviews included three types of electronic media-mediated interviews and one of a live face to face interview. There was a tendency in the media-mediated interviews that both the latency and the duration of interviewees' utterances in answering questions increased when they were compared with those of live face to face interviews. These results suggest that the interviewee became more verbose or talkative in the media-mediated interviews than in the live interviews. However, the interviewee's psychological tension was generally augmented in the media-mediated interviews, which was suggested by the delay of the initiation of conversations as compared to the conventional face-to-face interviews. We also discuss the applicability of media-mediated interviews by an electronic doctor which we are studying as a functional unit of our Hyper Hospital, a network based virtual reality space for medical care.

Text-to-speech synthesis (TTS) is currently one of the most important media conversion techniques. In this paper, we describe a Japanese TTS card developed for constructing a personal-computer-based multimedia platform, and a TTS software package developed for a workstation-based multimedia platform. Some applications of this hardware and software are also discussed. The TTS consists of a linguistic processing stage for converting text into phonetic and prosodic information, and a speech processing stage for producing speech from the phonetic and prosodic symbols. The linguistic processing stage uses morphological analysis, rewriting rules for accent movement and pause insertion, and other techniques to impart correct accentuation and a natural-sounding intonation to the synthesized speech. The speech processing stage employs the cepstrum method with consonant-vowel (CV) syllables as the synthesis unit to achieve clear and smooth synthesized speech. All of the processing for converting Japanese text (consisting of mixed Japanese Kanji and Kana characters) to synthesized speech is done internally on the TTS card. This allows the card to be used widely in various applications, including electronic mail and telephone service systems without placing any processing burden on the personal computer. The TTS software was used for an E-mail reading tool on a workstation.

Broadband multimedia information environments are part of the next big advance in communications and computer technology. The use of multimedia infrastructures in offices is becoming very important. This paper deals with a service concept and human interfaces based on a paper metaphor. The proposed service offers the advantages of paper and eliminates the disadvantages. The power of multimedia's expressiveness, user interaction, and hypermedia technology are key points of our solution. We propose a system configuration for implementing the service/human interface.

This paper describes a task-oriented speech dialogue system based on spontaneous speech understanding and response generation (TOSBURG). The system has been developed for a fast food ordering task using speaker-independent keyword-based spontaneous speech understanding. Its purpose being to understand the user's intention from spontaneous speech, the system consists of a noise-robust keyword-spotter, a semantic keyword lattice parser, a user-initiated dialogue manager and a multimodal response generator. After noise immunity keyword-spotting is performed, the spotted keyword candidates are analyzed by a keyword lattice parser to extract the semantic content of the input speech. Then, referring to the dialogue history and context, the dialogue manager interprets the semantic content of the input speech. In cases where the interpretation is ambiguous or uncertain, the dialogue manager invites the user to confirm verbally the system's understanding of the speech input. The system's response to the user throughout the dialogue is multimodal; that is, several modes of communication (synthesized speech, text, animated facial expressions and ordered food items) are used to convey the system's state to the user. The object here is to emulate the multimodal interaction that occurs between humans, and so achieve more natural and efficient human-computer interaction. The real-time dialogue system has been constructed using two general purpose workstations and four DSP accelerators (520MFLOPS). Experimental results have shown the effectiveness of the newly developed speech dialogue system.

This paper presents unique specification environments for LOTOS, which is one of FDTs (Formal Description Techniques) developed in ISO. We first discuss the large gap in terms of syntax and semantics between informal specifications at the early stage of specification design and formal specifications based on FDT such as LOTOS. This large gap has been bridged by human intelligent works thus far. In order to bridge the large gap, we have designed user-friendly specification environments for FDTs. The outlines of SEGL (Specification Environment for G-LOTOS), CBP (Concept-Based Programming environment) and MBP (Model-Based Programming environment) are described. The effectiveness of software development under such an environment is demonstrated using application examples from OSI and non-OSI protocols.

In speech output expected as an ideal man-machine interface, there exists an important issue on emotion production in order to not only improve its naturalness but also achieve more sophisticated speech interaction between man and machine. Speech has two aspects, which are prosodic information and phonetic feature. For the purpose of application to natural and high quality speech synthesis, the role of prosody in speech perception has been studied. In this paper, prosodic components, which contribute to the expression of emotions and their intensity, are clarified by analyzing emotional speech and by conducting listening tests of synthetic speech. The analysis is performed by substituting the components of neutral speech (i.e., one with no particular emotion) with those of emotional speech preserving the temporal correspondence by means of DTW. It has been confirmed that prosodic components, which are composed of pitch structure, temporal structure and amplitude structure, contribute to the expression of emotions more than the spectral structure of speech. The results of listening tests using prosodic substituted speech show that temporal structure is the most important for the expression of anger, while all of three components are much more important for the intensity of anger. Pitch structure also plays a significant role in the expression of joy and sadness and their intensity. These results make it possible to convert neutral utterances into utterances expressing various emotions. The results can also be applied to controlling the emotional characteristics of speech in synthesis by rule.

The development of computers capable of handling complex objects requires nonverbal interfaces that can bidirectionally mediate nonverbal communication including the gestures of both people and computers. Nonverbal expressions are poweful media for enriching and facilitating humancomputer interaction when used as interface languages. Four gestural modes are appropriate for human-computer interaction: the sign, indication, illustration and manipulation modes. All these modes can be conveyed by a generalized gesture interface that has specific processors for each mode. The basic component of the generalized gesture interface, a gesture dictionary, is proposed. The dictionary can accept sign and indicating gestures in which postures or body shapes are significant, pass their meaning to a computer and display gestures from the computer. For this purpose it converts body shapes into gestural codes by means of two code systems and, moreover, it performs bidirectional conversions of several gesture representations. This dictionary is applied to the translation of Japanese into sign language; it displays an actor who speaks the given Japanese sentences by gesture of sign words and finger alphabets. The performance of this application confirms the adequacy and usefulness of the gesture dictionary.

The new notion of "multiuser interface", an interface for groups working together in a shared workspace, originated from the expansion of CSCW research and the spread of the groupware concept. This paper introduces a new multiuser interface design approach based on the translucent video overlay technique. This approach was realized in the multimedia desktop conference system Team WorkStation. Team WorkStation demonstrates that this translucent video overlay technique can achieve two different goals: (1) fused overlay for realizing the open shared workspace, and (2) selective overlay for effectively using limited screen space. This paper first describes the concept of open shared workspace and its implementation based on the fused overlay technique. The shared work window of Team-WorkStation is created by overlaying translucent individual workspace images. Each video layer is originally physically separated. However, because of the spatial relationships among marks on each layer, the set of overlaid layers provides users with sufficient semantics to fuse them into one image. The usefulness of this cognitive fusion was demonstrated through actual usage in design sessions. Second, the problem of screen space limitation is described. To solve this problem, the idea of ClearFace based on selective overlay is introduced. The ClearFace idea is to lay translucent live face video windows over a shared work window. Through the informal observations of experimental use in design sessions, little difficulty was experienced in switching the focus of attention between the face images and the drawing objects. The theory of selective looking accounts for this flexible perception mechanism. Although users can see drawn objects behind a face without difficulty, we found that users hesitate to draw figures or write text over face images. Because of this behavior, we devised the "movable" face window strategy.

In order to realize flexible interaction control between user and information processing system, a special purpose user model is proposed on the basis of the knowledge-based design method of user interface system. The user-specific control knowledge of user-oriented interface environment is represented explicitly in the user model and utilized in the user-oriented interface system. Furthermore, the framework of user-oriented interface environment based on this user model called user-model-driven interface system, is proposed as one of user-adaptive human interface systems, in this paper. According to the proposed framework, a prototype system of the user-model-driven interface system is implemented and the facility of user-specific interaction control based on the user model has been verified with respect to an electronic mail handling task.

This paper discusses new trends and directions in human interface (HI) technologies, and the effects of HI technologies on human life or on social activities. This paper postulates that the HI subsumes man-machine interface, human-computer interaction, human-human interaction, human-organizational interface, human-environmental interface, human-social interface, etc. A new communication model, called Human Interface Communication Model (HICOM), and a new human dialogue model, called Human Interface Dialogue model (HIDIM), are derived by reexamining trends and directions on HI technologies from the viewpoint of functional meanings of interfaces, and from the viewpoint of a socially distributed cognition mechanism.