sensor

This research explores distributed sensing techniques for mobile devices using synchronous gestures. These are patterns of activity, contributed by multiple users (or one user with multiple devices), which take on a new meaning when they occur together in time, or in a specific sequence in time. To explore this new area of inquiry, this work uses tablet computers augmented with touch sensors and two-axis linear accelerometers (tilt sensors). The devices are connected via an 802.11 wireless network and synchronize their time-stamped sensor data. This paper describes a few practical examples of interaction techniques using synchronous gestures such as dynamically tiling together displays by physically bumping them together, discusses implementation issues, and speculates on further possibilities for synchronous gestures.

Soap is a pointing device based on hardware found in a mouse, yet works in mid-air. Soap consists of an optical sensor device moving freely inside a hull made of fabric. As the user applies pressure from the outside, the optical sensor moves independent from the hull. The optical sensor perceives this relative motion and reports it as position input. Soap offers many of the benefits of optical mice, such as high-accuracy sensing. We describe the design of a soap prototype and report our experiences with four application scenarios, including a wall display, Windows Media Center, slide presentation, and interactive video games.

In this paper, we will describe the TSI (Teething ring Sound Instrument), a new sound instrument given to babies, which consists of a teething ring, a knob, an I-CubeX Digitizer [1] and a computer which processes MIDI messages. The TSI is designed to bring music experience to baby with the movement of the babies reflex sucking motion. We provided the TSI to a baby and observed her action to the TSI and her reaction to the generated sound. This experiment showed the high potential of the TSI.

Although cell phones are extremely useful, they can be annoying and distracting to owners and others nearby. We describe sensing techniques intended to help make mobile phones more polite and less distracting. For example, our phone's ringing quiets as soon as the user responds to an incoming call, and the ring mutes if the user glances at the caller ID and decides not to answer. We also eliminate the need to press a TALK button to answer an incoming call by recognizing if the user picks up the phone and listens to it.

This research explores distributed sensing techniques for mobile devices using synchronous gestures. These are patterns of activity, contributed by multiple users (or one user with multiple devices), which take on a new meaning when they occur together in time, or in a specific sequence in time. To explore this new area of inquiry, this work uses tablet computers augmented with touch sensors and two-axis linear accelerometers (tilt sensors). The devices are connected via an 802.11 wireless network and synchronize their time-stamped sensor data. This paper describes a few practical examples of interaction techniques using synchronous gestures such as dynamically tiling together displays by physically bumping them together, discusses implementation issues, and speculates on further possibilities for synchronous gestures.

Powerful mobile devices with minimal I/O capabilities increase the likelihood that we will want to annex these devices to I/O resources we encounter in the local environment. This opportunistic annexing will require authentication. We present a sensor-based authentication mechanism for mobile devices that relies on physical possession instead of knowledge to setup the initial connection to a public terminal. Our solution provides a simple mechanism for shaking a device to authenticate with the public infrastructure, making few assumptions about the surrounding infrastructure while also maintaining a reasonable level of security.

This paper describes a testbed and method for characterizing the dynamic response of the type of spatial displacement transducers commonly used in virtual environment (VE) applications. The testbed consists of a motorized rotary swing arm that imparts known displacement inputs to the VE sensor. The experimental method involves a series of tests in which the sensor is displaced back and forth at a number of controlled frequencies that span the bandwidth of volitional human movement. During the tests, actual swing arm angle and reported VE sensor displacements are collected and time stamped. Because of the time stamping technique, the response time of the sensor can be measured directly, independent of latencies in data transmission from the sensor unit and any processing by the interface applications running on the host computer. Analysis of these experimental results allows sensor time delay and gain characteristics to be determined as a function of input frequency. Results from tests of several differnt VE spatial sensors (Ascension, Logitech, and Polhemus) are presented here to demonstrate use of the testbed and method.

In this paper, we present a methodology for recognizing seatedpostures using data from pressure sensors installed on a chair.Information about seated postures could be used to help avoidadverse effects of sitting for long periods of time or to predictseated activities for a human-computer interface. Our system designdisplays accurate near-real-time classification performance on datafrom subjects on which the posture recognition system was nottrained by using a set of carefully designed, subject-invariantsignal features. By using a near-optimal sensor placement strategy,we keep the number of required sensors low thereby reducing costand computational complexity. We evaluated the performance of ourtechnology using a series of empirical methods including (1)cross-validation (classification accuracy of 87% for ten posturesusing data from 31 sensors), and (2) a physical deployment of oursystem (78% classification accuracy using data from 19sensors).

This paper describes a testbed and method for characterizing the dynamic response of the type of spatial displacement transducers commonly used in virtual environment (VE) applications. The testbed consists of a motorized rotary swing arm that imparts known displacement inputs to the VE sensor. The experimental method involves a series of tests in which the sensor is displaced back and forth at a number of controlled frequencies that span the bandwidth of volitional human movement. During the tests, actual swing arm angle and reported VE sensor displacements are collected and time stamped. Because of the time stamping technique, the response time of the sensor can be measured directly, independent of latencies in data transmission from the sensor unit and any processing by the interface applications running on the host computer. Analysis of these experimental results allows sensor time delay and gain characteristics to be determined as a function of input frequency. Results from tests of several differnt VE spatial sensors (Ascension, Logitech, and Polhemus) are presented here to demonstrate use of the testbed and method.

Light Emitting Diodes (LEDs) offer long life, low cost, efficiency, brightness, and a full range of colors. Because of these properties, they are widely used for simple displays in electronic devices. A previously characterized, but little known property of LEDs allows them to be used as photo sensors. In this paper, we show how this capability can be used to turn unmodified, off the shelf, LED arrays into touch sensitive input devices (while still remaining capable of producing output). The technique is simple and requires little or no extra hardware - in some cases operating with the same micro-controller based circuitry normally used to produce output, requiring only software changes. We will describe a simple hybrid input/output device prototype implemented with this technique, and discuss the design opportunities that this type of device opens up.

Conventional scrolling methods for small sized display in PDAs or mobile phones are difficult to use when frequent switching of scrolling and editing operations are required, for example, browsing and operating large sized WWW pages.In this paper, we propose a new user-interface method to provide seamless switching between scrolling and other operations such as editing, based on "Paperweight Metaphor". A sheet of paper that has been placed on a slippery table is difficult to draw on. Therefore, in order to write or draw something on the sheet of paper, a person must secure the paper with his/her palm to avoid the paper from moving. This will be a good metaphor to design switching operation of scroll and editing modes.We have made prototype systems by placing a touch sensor under each PDA display where user's palm will be hit. Three application programs - map browser, WWW browser, and photograph browser - that switch between scrolling and other operation modes depending on sensor output have been developed. We have carried out user tests on this mode switching method and have received favorable feedback on the same.