Seongkook Heo

Force gestures: augmenting touch screen gestures with normal and tangential forces

Force gestures are touch screen gestures augmented by the normal and tangential forces on the screen. In order to study the feasibility of the force gestures on a mobile touch screen, we implemented a prototype touch screen device that can sense the normal and tangential forces of a touch gesture on the screen. We also designed two example applications, a web browser and an e-book reader, that utilize the force gestures for their primary actions. We conducted a user study with the prototype and the applications to study the characteristics of the force gestures and the effectiveness of their mapping to the primary actions. In the user study we could also discover interesting usability issues and collect useful user feedback about the force gestures and their mapping to GUI actions.

SplitBoard: A Simple Split Soft Keyboard for Wristwatch-sized Touch Screens

Text entry on a smartwatch is a challenging problem due to the devices limited screen area. In this paper, we introduce the SplitBoard, which is a soft keyboard designed for a smartwatch. As the user flicks left or right on the keyboard, it switches between the left and right halves of a QWERTY keyboard. We report the results of two user experiments where the SplitBoard was compared to an ordinary QWERTY keyboard, the ZoomBoard, SlideBoard, and Qwerty-like keypad. We measured the initial performance with new users for each method. The SplitBoard outperformed all other techniques in the experiments. The SplitBoard is expected to be a viable option for smartwatch text entry because of its light processing requirements, good performance, and immediate learnability.

ForceDrag : using pressure as a touch input modifier

It is common to use modifier keys in a PC environment in order to change drag modes, but mobile devices with a touch screen do not provide this option. Thus, we present ForceDrag to address this issue, which is a touch drag operation where pressure is used as a modifier key to change touch drag modes. We also introduce the concept of force lock and we compare three selection techniques for performing a force lock in a user study. We also describe a prototype implementation and discuss early user feedback on ForceDrag.

LongPad: a touchpad using the entire area below the keyboard of a laptop computer

In this paper, we explore the possibility of a long touchpad that utilizes the entire area below the keyboard of a laptop computer. An essential prerequisite for such a touchpad is a robust palm rejection method, which we satisfy using a proximity-sensing touchpad. We developed LongPad, a proximity-sensing optical touchpad that is as wide as a laptop keyboard, and implemented a palm rejection algorithm that utilizes proximity images from LongPad. In a user study conducted, we observed that LongPad rejected palm touches almost perfectly while participants were repeating typing and pointing tasks. We also summarize the new design space enabled by LongPad and demonstrate a few of the interaction techniques it facilitates.

ThickPad: a hover-tracking touchpad for a laptop

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 touchpad meets a laptop

Expanding touch input vocabulary by using consecutive distant taps

In recent years, touch screens have emerged and matured as the main input interface for mobile and tablet computers calling for extended touch input possibilities. In this paper, we explore the use of consecutive distant taps to expand the touch screen input vocabulary. We analyzed time intervals and distances between consecutive taps during common applications on a tablet and verified that consecutive distant taps can be used conflict-free with existing touch gestures. We designed the two interaction techniques Ta-tap and Ta-Ta-tap that utilize consecutive distant taps. Ta-tap uses two consecutive distant taps to invoke alternative touch operations for multi-touch emulation, whereas Ta-Ta-tap uses a series of consecutive distant taps to define a spatial gesture. We verified the feasibility of both interaction techniques through a series of experiments and a user study. The high recognition rate of Ta-tap and Ta-Ta-tap gestures, the few conflicts with existing gestures, and the positive feedback from the participants assert the potential of consecutive distant taps as a new design space to enrich touch screen interactions.

Mining social relationship types in an organization using communication patterns

Our goal is to show that it is possible to automatically infer social relationship types among people who stay together in an organization by analyzing communication patterns. We collected indoor co-location data and instant messenger data from 22 participants for one month. Based on the data, we designed and explored several indicators which are considered to be useful for mining social relationship types. We applied machine learning techniques using the indicators and found that it is possible to develop an intelligent method to infer social relationship types.

Designing rich touch interaction through proximity and 2.5D force sensing touchpad

The touchpad is the de facto standard input device for controlling the GUI on portable computers. Most touchpads detect only finger contact and ignores other physical actions, such as applying force or hovering over the device. In this paper, we introduce a novel touchpad capable of tracking finger hover and measuring normal and shear forces. We also present two design strategies for the hover- and force-enhanced touchpad: multi-level user interaction and mimicry of physical manipulation. We illustrate the two design strategies using two applications that we developed based on the design strategies.

IrCube tracker: an optical 6-DOF tracker based on LED directivity

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 tracker is basically source localization by solving an inverse problem. We implemented a prototype system for a TV viewing environment, verified the feasibility of the operating principle, and evaluated the basic performance of the prototype system in terms of accuracy and speed. We also examined its application possibility to different environments, such as a tabletop computer, a tablet computer, and a mobile spatial interaction environment.

Trampoline: a double-sided elastic touch device for repoussé and chasing techniques

Relief is often used to add patterns to product surfaces, but interaction techniques for modeling relief on the surface of virtual objects have not received due attention. We adopt the repoussé and chasing artwork techniques in an alternative interaction technique for modeling relief on virtual surfaces. To support the interaction technique, we develop a double-sided touchpad called Trampoline that can detect the position and force of a finger touch on both sides. In addition, it provides an elastic feedback to users as the surface consists of an elastic fabric. With this device and the interaction technique developed, we implement a relief application and present modeling results that demonstrate the efficacy of our system.