Kosuke Nakajima

PUCs: detecting transparent, passive untouched capacitive widgets on unmodified multi-touch displays

Capacitive multi-touch displays are not designed to detect passive objects placed on them-in fact, these systems usually contain filters to actively reject such touch data. We present a technical analysis of this problem and introduce Passive Untouched Capacitive Widgets (PUCs). Unlike previous approaches, PUCs do not require power, they can be made entirely transparent, they are detected reliably even when no user is touching them, and they do not require internal electrical or software modifications of the touch display or its driver. We show the results from testing PUCs on 17 different off-the-shelf capacitive touch display models, and provide initial technical design recommendations.

Recognizing Depression from Twitter Activity

In this paper, we extensively evaluate the effectiveness of using a users 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.

Emoballoon: A balloon-shaped interface recognizing social touch interactions

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.

Ambient Suite: enhancing communication among multiple participants

We propose a room-shaped information environment called Ambient Suite that enhances communication among multiple participants. 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. Such nonverbal cues as utterances, positions, and gestures are measured to sense participant states. The participants are surrounded by displays so that various types of information can be given based on their states. Although this system is adaptable to a wide range of situations where groups talk with each other, our implementation assumed standing-party situations as a typical case. Using this implementation, we experimentally evaluated the performance of input, output, and whether our system can actually stimulate conversation. The results showed that our system measured sensor data to recognize the conversational states, presented information, and adequately encouraged participant conversations.

FuSA 2 Touch Display: A furry and scalable multi-touch display

We propose a furry and scalable multi-touch display called the “FuSA2 Touch 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.

Polka dot: the garden of water spirits

Physical and tangible representations of information have provided users with intuitive interactions in which users can control information through tangible controls using their hands. In these techniques, flexible materials have often been utilized. For example, clay has been used for an intuitive modeling tool which senses the shape of the clay and updates its 3D model data [Piper et al. 2002]. This example enables users to create 3D models without knowledge of computational methods for constructing 3D models. Though these tangible representations of information accept user input, they cannot provide bi-directional physical interactions since their physical properties are not controlled by computers. Therefore, it is difficult to represent dynamic changes of information using physical properties such as motion, size, and color. These tangible user interfaces employ static materials.

PUCs demo: detecting transparent, passive untouched capacitive widgets

Capacitive multi-touch displays are designed to detect touches from fingers that often change the location. This is quite the opposite of our goal: detect passive objects placed on them. In fact, these systems usually contain filters to actively reject such inactive input data. We present a technical analysis of this problem and introduce Passive Untouched Capacitive Widgets (PUCs). Unlike previous approaches, PUCs do not require power, they can be made entirely transparent, and they do not require internal electrical or software modifications. Most importantly they are detected reliably even when no user is touching them.

Ambient Suite: Room-shaped information environment for interpersonal communication

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.