Jong-Woon Yoo

A Cooperative Clustering Protocol for Energy Saving of Mobile Devices with WLAN and Bluetooth Interfaces

One of the most widely used wireless communication standards is a Wireless Local Area Network (WLAN) (IEEE 802.11). However, WLAN has a serious power consumption problem. In this paper, we propose a novel energy saving approach that exploits the multiradio feature of recent mobile devices equipped with WLAN and Bluetooth interfaces. Unlike previous approaches, our work is based on clustering. In our work, a cluster is a Bluetooth Personal Area Network (PAN), which consists of one cluster head and several regular nodes. The cluster head acts as a gateway between the PAN and the WLAN, enabling the regular nodes to access the WLAN infrastructure via low-power Bluetooth. We present a distributed clustering protocol, Cooperative Networking protocol (CONET), which dynamically reforms clusters according to each nodes bandwidth requirement, energy use, and application type. CONET does not require modifications of existing wireless infrastructures because clustering is performed independently of WLAN access points. We implemented the CONET prototype with four wearable computing devices to evaluate the performance on real hardware. We also simulated CONET for large networks of more than 100 mobile nodes. Both results demonstrate that our approach is effective in reducing the power consumption of WLAN.

A Ubiquitous Fashionable Computer with an i-Throw Device on a Location-Based Service Environment

The ubiquitous fashionable computer (UFC), introduced in this paper, is a wearable computer that allows people to exploit ubiquitous computing environment in a user-friendly manner. We present the design approach and philosophy of the UFC that is wearable, aesthetic, and intuitive. The UFC supports the interoperability of various communication interfaces among WLAN, Bluetooth and ZigBee devices. We developed a wireless gesture recognition device, called i -Throw, which is small enough to be worn on ones finger like a ring. The UFC, with the help of i -Throw, can control ubiquitous environment using an intuitive hand motion. To explain the practical use of the UFC platform and the user-friendly interaction with ubiquitous environment, we implemented a ubiquitous testbed where multiple UFC users interact with various ubiquitous devices or other UFC users. In addition, we implemented a practical application which makes it possible to exchange the various objects and control ubiquitous devices very easily.

An Android-based automotive middleware architecture for plug-and-play of applications

Modern vehicles are getting increasingly smarter and evolving to become new mobile computing platforms. As the software platformization of vehicles advances, the demands for reconfigurable cars, installing and upgrading vehicle software as plug-and-play have also grown. However, the existing automotive software platforms are not designed for dynamic reconfiguration and plug-and-play. This paper addresses the plug-and-play challenge in the recent automotive systems. Drawing from recent advancements in the mobile phone operating systems, we propose an Android-based software architecture which supports the play-and-play in automotive systems. In our architecture, an application can be downloaded from cloud services and executed on ECUs in a distributed fashion. Before installing an application, our system performs schedulability analysis to check real-time performance requirements for recent vehicles. We also present a model-based development tool for designing a workflow of automotive applications for our system. We implement a prototype and demonstrate the feasibility of our approach.

An intuitive data transfer technique using bartender's gestures

This technical demonstration presents Cocktail, a gesture-based mobile interaction system, which is designed for providing a user-friendly way of exchanging multimedia data with intuitive gestures. Our system is motivated by bartenders who make cocktails with interesting gestures, such as pouring and shaking. These gestures are used in our interaction system for data transfer and contents creation: a user can pour (transfer) data in his/her mobile phone to other devices in the same way that a bartender pours drinks to a shaker. The user can also mix music files and pictures into a multimedia content, such as a music video file, by shaking the mobile phone, as a bartender does to mix different drinks into a cocktail. We have implemented a prototype of Cocktail using smart phones and demonstrate its usability.

PokerFace: Game players themselves are truly memorable

Video games support instant replays so that game players can see previously occurred events (e.g., goals in sports games) again from a different point of view and permanently store such exciting moments and feelings as pleasant memories. However, players are likely to have different feelings and enjoyment depending on the player context, such as who they play with, their looks, or conversation during gaming even for the same game. Therefore, instant replays without such player context are not enough for users to remind the enjoyable moments that could not happen again, and thus precious memories will be forgotten. This paper presents PokerFace, a new video game console that provides advanced instant replays containing the player context. PokerFace detects memorable situations during gaming and generates advanced instant replays by combining both the game replay and the users reaction and synchronizes them in time so that the players can see both their own looks and those of other players at the time when the exciting moment take place. Our system provides game players with better memories by storing advanced instant replays into the permanent storage or web blogs. We have implemented a prototype of PokerFace and conducted user studies. From the evaluation results, we conclude that PokerFace can have the competitiveness in game consoles market by giving more enjoyment and better memories for users.

U-TOPIA: A Ubiquitous Environment with a Wearable Platform, UFC and Its Security Infrastructure, pKASSO

U-TOPIA, introduced in this paper, is an advanced ubiquitous computing environment mainly focusing on a university campus. Research in U-TOPIA spans various components each of which is essential to realize U-TOPIA: from user device hardware/software, user interface, communication technology, indoor/outdoor testbed, middleware to practical applications and security infrastructure. We designed and implemented a wearable platform from the scratch and make use of it as a main user device inside U-TOPIA. In addition to this, as a new user interface, we developed a wireless gesture recognition device, called i-Throw to communicate with U-TOPIA in an intuitive manner. For data communication and location tracking in U-TOPIA, campus-wide indoor and outdoor testbed was deployed. To keep up with secure and dynamic U-TOPIA environment, a new security infrastructure,called pKASSO, and extensible middleware, μ-ware, was developed. Finally, as a practical application for U-TOPIA, we implemented a ubiquitous testbed room where multiple users interact with various ubiquitous devices or other users securely in a user-friendly manner. Integrating these components all together, we show that U-TOPIA can be a realistic role model to improve current paradigm of ubiquitous computing environment one step forward within a few years.