Chi Tai Dang

Hand distinction for multi-touch tabletop interaction

Recent multi-touch multi-user tabletop systems offer rich touch contact properties to applications. Not only they provide touch positions, but also finger orientations. Applications can use these properties separated for each finger or derive information by combining the given touch contact data. In this paper, we present an approach to map fingers to their associated joined hand contributing to potential enhancements for gesture recognition and user interaction. For instance, a gesture can be composed of multiple fingers of one hand or different hands. Therefore, we present a simple heuristic for mapping fingers to hands that makes use of constraints applied to the touch position combined with the finger orientation. We tested our approach with collected diverse touch contact data and analyze the results.

Natural interaction with culturally adaptive virtual characters

Recently, the verbal and non-verbal behavior of virtual characters has become more and more sophisticated due to advances in behavior planning and rendering. Nevertheless, the appearance and behavior of these characters is in most cases based on the cultural background of their designers. Especially in combination with new natural interaction interfaces, there is the risk that characters developed for a particular culture might not find acceptance when being presented to another culture. A few attempts have been made to create characters that reflect a particular cultural background. However, interaction with these characters still remains an awkward experience in particular when it comes to non-verbal interaction. In many cases, human users either have to choose actions from a menu their avatar has to execute or they have to struggle with obtrusive interaction devices. In contrast, our paper combines an approach to the generation of culture-specific behaviors with full body avatar control based on the Kinect sensor. A first study revealed that users are able to easily control an avatar through their body movements and immediately adapt its behavior to the cultural background of the agents they interact with.

Surface-poker: multimodality in tabletop games

Multimodal interaction and face-to-face communication between players are aspects of traditional board games which contribute to their popularity. Such aspects are also typical of digital tabletop games. But in addition to that, digital systems allow for a higher level of multimodality through utilizing novel interaction devices or physiological input data. In this paper, we describe a multimodal tabletop Poker game which makes use of both: additional interaction devices and physiological input data. We outline the tabletop game, the interaction modalities involved, and observations of players.

Usage and recognition of finger orientation for multi-touch tabletop interaction

Building on the observation that finger orientation is an inherent part of humans interaction in the real world, exploiting finger orientation for multitouch tabletop interaction would facilitate more natural interaction techniques. We motivate this by means of examples where the finger orientation improves or enriches interaction. Afterwards, we present a simple and fast approach to detect the finger orientation reliably for multi-touch tabletop interaction. The steps involved are computationally cheap and therefore suit the needs of tracking software operating under time-critical conditions. We show that the presented approach enables the detection of finger orientation also for fingers that touch the tabletop surface only slightly. Further, recognition rates on real data gained from the camera within a multi-touch tabletop are presented in order to give a measure for the precision and reliability of the presented approach.

Proxy-based Security for the Session Initiation Protocol (SIP)

There is a trend towards voice-over-IP systems based on the session initiation protocol (SIP), which is a protocol for session management in general. However, as signalling data is transferred using the Internet, systems face security problems. Thus, at least authentication of the participants and confidentiality of signalling data have to be ensured as basic mechanism. In this work, we propose a mechanism for assuring the identity of a group of users fulfilling the same role (e.g., employees of a customer call centre). Using our concept enables using only one certificate for the whole group for signing and encrypting messages according to the SIP standard. Our mechanism works transparently for users as we provide a special proxy server for this purpose, which significantly reduces administration efforts and resource needs on the participating nodes. Furthermore, such a proxy server can be used for transparently validating and decrypting SIP messages as well. This reduces efforts on the terminals, resulting in an improved resource-usage, e.g., on a personal digital assistant. We provide an implementation of the concept based on the NIST SIP proxy server.

TabletopCars: interaction with active tangible remote controlled cars

In this paper, we report on the development of the competitive tangible tabletop game TabletopCars, which combines the virtual world with the physical world. We brought together micro scaled radio controlled cars as active tangibles with an interactive tabletop surface to realize the game. Furthermore, we included Microsoft Kinect depth sensing as an interaction mode for embedded and embodied interaction. Our aim was to investigate the possibilities that emerge through the augmentation capabilities of interactive tabletops for creating novel game concepts and the interaction modes that novel input devices facilitate. This work presents TabletopCars as a testbed for embedded and embodied interaction and describes the system in detail. Finally, we report on a preliminary user study where users controlled the active tangible micro scaled cars through hand gestures.

A framework for the development of multi-display environment applications supporting interactive real-time portals

Advances in multi-touch enabled interactive tabletops led to many commercially available products and were increasingly deployed at places beyond research labs, for example at exhibitions, retail stores, or showrooms. At the same time, small multi-touch devices, such as tablets or smartphones, became prevalent in our daily life. When considering both trends, occasions and scenarios where tabletop systems and mobile devices form a coupled interaction space are expected to become increasingly widespread. However, application development or research prototypes for those environments will foreseeable require considerable resources when considering nowadays heterogeneity of device platforms and the functionality to establish a connected interaction space. To address these concerns, this paper discusses challenges and answers questions that arose during design and implementation of the Environs framework, a multi-display environment software framework that eases development of interactive distributed applications. In particular, Environs enables applications utilizing video portals that put high requirements on responsiveness and latency.

A Multi-Display System for Deploying and Controlling Home Automation

In this paper, we present a concept of using a home devices mashup tool to wire home devices on a tabletop display in combination with web based UIs on mobile devices to control home devices. This concept is realized by a multi-display system supported by the open-source framework Environs. The mashup tool on the tabletop enables multiple people to deploy home networked devices co-located collaboratively with a more natural and intuitive interface. Moreover, web based UIs on mobile devices enable individuals to control home devices universally with high accessibility and mobility.

DrinkWatch: A Mobile Wellbeing Application Based on Interactive and Cooperative Machine Learning

We describe in detail the development of DrinkWatch, a wellbeing application, which supports (alcoholic and non-alcoholic) drink activity logging. DrinkWatch runs on a smartwatch device and makes use of machine learning to recognize drink activities based on the smartwatch»s inbuilt sensors. DrinkWatch differs from other mobile machine learning applications by triggering feedback requests from its user in order to cooperatively learn the user»s personalized and contextual drink activities. The cooperative approach aims to reduce limitations in learning performance and to increase the user experience of machine learning based applications. We discuss why the need for cooperative machine learning approaches is increasing and describe lessons that we have learned throughout the development process of DrinkWatch and insights based on initial experiments with users. For example, we demonstrate that six to eight hours of annotated real world data are sufficient to train a reliable base model.

Model-Driven Development of Adaptive Applications with Self-Adaptive Mobile Processes

Writing adaptive applications is complex and thus error-prone. Our (SAM-WS s) already provide adaptation support in terms of location, available state, provided functionality and implementation in use. Yet, SAM-WS s still require developers implementing the adaptation logic themselves. In this work, we present an approach to ease the implementation of adaptive applications with SAM-WS s. We introduce our concept of a (SAMProc) , an abstraction for adaptive applications, and SAMPEL , an XML application to describe a SAMProc . We show a tool that automatically generates SAM-WS s adaptation code on the basis of the SAMPEL description. Then, we go even one step further by providing an Eclipse plug-in that allows automatic generation of the SAMPEL description on the basis of a graphic model. This enables generating a SAM-WS implementation with few clicks; developers have to write pure application logic only.