The sensation of a drink in the throat is a salient example of the internal bodily feelings that shape our eating experiences. Computationally modeling these sensations would enable their redesign and inform technologies that augment how we eat. However, methods for quantifying such subjective, internal states from objective cues remain underdeveloped. This paper introduces a computational approach to bridge this gap. A first study (N = 31) models subjective ratings from laryngeal skin temperature and ingested volume, revealing distinct, individual Interoceptive Profiles. Informed by these findings, we developed a wearable device that provides thermal feedback to the larynx. A second study (N = 20) demonstrates that this intervention can alter drink sensations, contingent on the user’s sensory profile. Based on these findings, we highlight the potential of the larynx as a site for bidirectional interaction (sensing and modulating) and propose a novel approach for personalized sensory augmentation.

The replication of object stiffness is essential for enhancing haptic feedback in virtual environments. However, existing research has overlooked how stylus stiffness influences the perception of virtual object stiffness during tool-mediated interactions. To address this, we conducted a psychophysical experiment demonstrating that changing stylus stiffness combined with visual stimuli altered users’ perception of virtual object stiffness. Based on these insights, we developed Transtiff, a stylus-shaped interface capable of on-demand stiffness control using a McKibben artificial muscle mechanism. Unlike previous approaches, our method manipulates the perceived stiffness of virtual objects via the stylus by controlling the stiffness of the stylus without altering the properties of the real object being touched, creating the illusion of a hard object feeing soft. Our user study confirmed that Transtiff effectively simulates a range of material properties, such as sponge, plastic, and tennis balls, providing haptic rendering that is closely aligned with the perceived material characteristics. By addressing the challenge of delivering realistic haptic feedback through tool-based interactions, Transtiff represents a significant advancement in the haptic interface design for VR applications.

Proximity interaction, such as hugging, plays an essential role in building relationships between parents and children. However, parents and children cannot freely interact in the neonatal intensive care unit due to visiting restrictions imposed by COVID-19. In this study, we develop a system of pseudo-proximity interaction with a remote infant through a VR headset by using an infant-like device that reproduces the haptic feedback features of the hugging sensation, such as weight, body temperature, breathing, softness, and unstable neck.

We propose TuVe, a novel shape-changing display consisting of a flexible tube and fluids, in which the droplets flowing through the tube compose the display medium that represents information. In this system, every colored droplet is flowed by controlling valves and a pump connected to the tube. The display part employs a flexible tube that can be shaped to any structure (e.g., wrapped around a specific object), which is achieved by a calibration made to capture the tube structure using image processing with a camera. A performance evaluation reveals that our prototype succeeds in controlling each droplet with a positional error of 2 mm or less, which is small enough to show such simple characters as alphabetic characters using a 7 × 7-pixel resolution display. We also discuss example applications, such as large public displays and flow-direction visualization, that illustrate the characteristics of the TuVe display.

This paper proposes a highly parallelized 3D node localization method based on cross-entropy method for the 3D modeling system. Cross-entropy localization statistically estimates node positions from node-to-node distance information by sampling, and each sample evaluation and internal computation of objective function can be processed in parallel. Experimental results show our GPGPU-based implementation achieved 5,163x and 61.5x speed up compared to a single processor and 80-processor implementations. In addition, for enhancing model reproduction accuracy, this work introduces a penalty function to mitigate flip ambiguity.

In this paper, we propose a novel interactive display, Ketsuro-Graffiti, that provides information with water condensation. Recently, a lot of substantial displays have been proposed that utilize various types of physical material. These displays enable users to touch each pixel freely. Water condensation exists ubiquitously in daily life, and drawing on it is familiar. Therefore, a display with water condensation achieves an intuitive and familiar interaction between users and information. We propose a method to control generation and evaporation of water condensation and implement two prototypes of Ketsuro-Graffiti using peltier devices. One prototype uses an open loop control system and the other uses a PID closed loop control system with thermistors. Our evaluation of system performance indicates that both prototypes can control generation, evaporation, and thickness of water condensation.

In this paper, we extensively evaluate the effectiveness of using a user's social media activities for estimating degree of depression. As ground truth data, we use the results of a web-based questionnaire for measuring degree of depression of Twitter users. We extract several features from the activity histories of Twitter users. By leveraging these features, we construct models for estimating the presence of active depression. Through experiments, we show that (1) features obtained from user activities can be used to predict depression of users with an accuracy of 69%, (2) topics of tweets estimated with a topic model are useful features, (3) approximately two months of observation data are necessary for recognizing depression, and longer observation periods do not contribute to improving the accuracy of estimation for current depression; sometimes, longer periods worsen the accuracy.

This paper proposes a 3D node localization method that uses cross-entropy method for the 3D modeling system. The proposed localization method statistically estimates the most probable positions overcoming measurement errors through iterative sample generation and evaluation. The generated samples are evaluated in parallel, and then a significant speedup can be obtained. We also demonstrate that the iterative sample generation and evaluation performed in parallel are highly compatible with interactive node movement.

We propose a novel interactive display called Ketsuro-Graffiti, which allows users to write or apply graffiti to the surface of water-condensed mirror-like displays. Ketsuro-Graffiti controls the temperature of arbitrary points on its surface by moving heat conductive actuators up and down to control the condensation's generation and evaporation. We describe the details of its implementation and preliminary evaluation results.

We propose a portable umbrella-shaped device called U-brella as an application of “vibrationizing” information. Vibrationizing is a term coined to mean the transformation of various types of information into a vibration. Funbrella is an earlier version of U-brella that allows users to experience rain with vibrations, while U-brella offers them the ability to feel ultraviolet rays by converting them into vibration. We first conceptualized the implementation of U-brella: improving the mechanism of Funbrella's vibration generator to make it lighter and easier to carry. Then we conducted a user study to confirm the efficiency of our system's vibrationizing and users' impressions of U-brella. The results showed that the participants easily perceived the amount of ultraviolet rays and that they really felt the rays pour down upon their heads with U-brella.

This paper describes Ambient Party Room, which is a room-shaped information environment for party situations. This system estimates the conversation states by measuring participants' nonverbal cues and displays various types of information to stimulate the conversation. In this study, we reconstructed the system architecture from an early prototype and newly examined several types of information stimulus using a floor display, wall displays, and speakers. We conducted an experiment in which six participants talked freely in Ambient Party Room. Results showed that both profile-based information stimulus and feedback information of participants' behaviors contributed to their activated conversations.

People often communicate with others using social touch interactions including hugging, rubbing, and punching. We propose a soft social-touchable interface called “Emoballoon” that can recognize the types of social touch interactions. The proposed interface consists of a balloon and some sensors including a barometric pressure sensor inside of a balloon, and has a soft surface and ability to detect the force of the touch input. We construct the prototype of Emoballoon using a simple configuration based on the features of a balloon, and evaluate the implemented prototype. The evaluation indicates that our implementation can distinguish seven types of touch interactions with 83.5% accuracy.

In this paper, we investigate the effectiveness of the records of user's activities in Twitter, which is a popular microblogging site, for estimating his/her depressive tendency. We construct multiple regression model to estimate user's depressive tendency from the frequencies of words used by the user. We perform experiments to estimate participants' depressive tendencies using the constructed regression model. Our experimental results show that there exists medium positive correlation (correlation coefficient r ≃ 0.45) between the Zung's Self-rating Depression Scale, which is a popular measure for estimating depressive tendency, and estimated score obtained from the regression model.

We propose a room-shaped information environment called Ambient Suite that enhances interpersonal communication. In Ambient Suite, the room itself works as both sensors to estimate the conversation states of participants and displays to present information to stimulate conversation. This paper introduces an implementation assumed standing-party situations as a typical use case of Ambient Suite. From the result of user study using its implementation, we confirmed that our system adequately encouraged participant conversations.

We propose a cup-shaped device called Cup-le for conversational experiment. Cup-le has various sensors to record participants' nonverbal behavior such as utterance. Cup-le saves the work of attaching sensors. Also, since Cup-le appears cup-shaped, it can sense without being aware of the sensor unlike conventional wearable sensors. Moreover, by attaching touch display, Cup-le can show information and can be operated. In this conversational experiment, we use the input-output as method to have a questionnaire during the experiment and capture participants' impression for their conversation. We conducted real conversational experiment with Cup-le, and we confirmed that Cup-le supported sufficiently the experiment without affecting their impression.

We propose a furry and scalable multi-touch display called the “FuSA2Touch Display.” The furry type of tactile sensation of this surface affords various interactions such as stroking or clawing. The system utilizes plastic fiber optic bundles to realize a furry-type texture. The system can show visual feedback by projection and detects multi-touch input. We implemented a 24-inch display, and found that our implemented display encourages users to interact with it in various actions.

In this paper, we present our vision on large-scale and dynamic social network analysis in real environment, which is expected to be enabled by introduction of large-scale heterogeneous sensors in ambient environment. We address challenges toward realization of large-scale dynamic social network analysis in real environment, and discuss several promising applications. We finally present our preliminary experimental results of dynamic social network analysis for six-person social gatherings in real environment.

"MADO Interface" is a tangible user interface consisting of a compact touch-screen display and physical blocks. "MADO" means "window" in Japanese, and MADO Interface is utilized as the real window into the virtual world. Users construct a physical object by simply combining electrical blocks. Then, by connecting MADO Interface to the physical object, they can watch the virtual model corresponding to the physical block configuration (shape, color, etc.) The size and the viewpoint of the virtual model seen by the user depend on the position of MADO Interface, maintaining the consistency between the physical and virtual worlds. In addition, users can interact with the virtual model by touching the display on MADO Interface. These features enable users to explore the virtual world intuitively and powerfully.

We propose a novel interface called Tearable that allows users to continuously experience the real sense of tearing paper. To provide such a real sense, we measured the actual vibration data of tearing a piece of real paper and analyzed them. Based on this data, we utilized hook-and-loop fasteners and a DC motor for representing the sense of tearing. We compared the force given by Tearable with that by a piece of real paper and recommended its reproducibility and usability. In addition, we evaluated Tearable with questionnaires after user experiences.

Multi-display environments compose displays that can be at different locations from and different angles to the user; as a result, it can become very difficult to manage windows, read text, and manipulate objects. We investigate the idea of perspective as a way to solve these problems in multi-display environments. We first identify basic display and control factors that are affected by perspective, such as visibility, fracture, and sharing. We then present the design and implementation of E-conic, a multi-display multi-user environment that uses location data about displays and users to dynamically correct perspective. We carried out a controlled experiment to test the benefits of perspective correction in basic interaction tasks like targeting, steering, aligning, pattern-matching and reading. Our results show that perspective correction significantly and substantially improves user performance in all these tasks.

We present a novel method for interactive retrieval of 3D shapes using ysical objects. Our method is based on simple ysical 3D interaction with a set of tangible blocks. As the user connects blocks, the system automatically recognizes the shape of the constructed ysical structure and picks similar 3D shape models from a preset model database, in real time. Our system fully supports interactive retrieval of 3D shape models in an extremely simple fashion, which is completely non-verbal and cross-cultural. These advantages make it an ideal interface for inexperienced users, previously barred from many applications that include 3D shape retrieval tasks.

Assessments of spatial, constructional ability are used widely in cognitive research and in clinical diagnosis of disease or injury. Some believe that three-dimensional (3D) forms of these assessments would be particularly sensitive, but difficulties with consistency in administration and scoring have limited their use. We describe Cognitive Cubes, a novel computerized tool for 3D constructional assessment that increases consistency and promises improvements in flexibility, reliability, sensitivity and control. Cognitive Cubes makes use of ActiveCube, a novel tangible user interface for describing 3D shape. In testing, Cognitive Cubes was sensitive to differences in cognitive ability and task, and correlated well to a standard paper-and-pencil 3D spatial assessment

ActiveCube is a bi-directional user interface that supports a person's creative work through constructing and interacting with 3D virtual objects by using actual physical cubes. With this flexible interface, the user can easily construct various 3D structures in a virtual environment by simply combining the cubes. All of the faces of the cubes are the same and can be connected to any face of any other cube. A computer recognizes the constructed 3D structure in real time, so consistency is always maintained between the real environment and its corresponding representation in a virtual environment. Each cube is equipped with a processor for autonomous simulation and communication functions between cubes. A cube also utilizes a sensor for detecting the operational intention of the user and/or a display/actuator used as an output channel. Users can interact with ActiveCube in various ways by using the sensors, and the response to the interaction is also shown by displays/actuators installed on the cube. Each ActiveCube is equipped with both input and output devices, which makes the interface intuitive and helps to clarify the causal relationship between the input of the user's operational intention and the output of simulation results.