Sangwon Choi

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As an emerging wearable device, a number of commercial smartwatches have been released and widely used. While many people have concerns about the battery life of a smartwatch, there is no systematic study for the main usage of a smartwatch, its battery life, or battery discharging and recharging patterns of real smartwatch users. Accordingly, we know little(More)
We explored the use of a hover tracking touchpad in a laptop environment. In order to study the new experience, we implemented a prototype touchpad consisting of infrared LEDs and photo-transistors, which can track fingers as far as 10mm over the surface. We demonstrate here three major interaction techniques that would become possible when a hover-tracking(More)
We explored the possibility of touch-screen-like interaction with a remote control in the TV-viewing environment. A shadow representing the user's thumb touches the screen, presses a button, flicks a cover-flow list, and draws a simple stroke, while the thumb stays and moves on and above the touchpad. In order to implement the concept we developed an(More)
Today's smartphone application (hereinafter 'app') markets miss a key piece of information, power consumption of apps. This causes a severe problem for continuous sensing apps as they consume significant power without users' awareness. Users have no choice but to repeatedly install one app after another and experience their power use. To break such an(More)
Six-degrees-of-freedom (6-DOF) trackers, which were mainly for professional computer applications, are now in demand by everyday consumer applications. With the requirements of consumer electronics in mind, we designed an optical 6-DOF tracker where a few photo-sensors can track the position and orientation of an LED cluster. The operating principle of the(More)
A touchpad has been the most popular pointing device for laptop computers. As large, multi-touch sensing touchpads are now common, we came to think about extending its input vocabulary by adding area gestures. In order to explore this possibility, we constructed a laptop-like mock-up with an optical, proximity sensing touchpad, and implemented a few area(More)
Recently, a number of continuous sensing applications have been actively proposed in research communities and commercially released in the market. However, due to their unique power characteristics, user behavior-dependent battery drain, they bring new challenges for users' power management on these applications. In this demonstration, we present a(More)
An aluminum metal, both native and with a very thin oxide film, was investigated as an anode for aluminum-ion batteries. Investigations were carried out in an acidic ionic liquid electrolyte, composed of AlCl3 in 1-ethyl-3-methylimidazolium chloride ([EMIm]Cl), with β-MnO2/C as a cathode. The battery based on Al metal with a very thin oxide film showed high(More)
In this poster, we propose an emotion analysis method using context information gathered from sensor data. We observe that there are certain situations in which a specific emotion is strongly felt, i.e. dominant. We develop a "scenario-based" approach that focuses on creating such situations with dominant emotion, using a set of context information from(More)
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