u-texture: Self-Organizable Universal Panels for Creating Smart Surroundings

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1 19 u-texture: Self-Organizable Universal Panels for Creating Smart Surroundings Naohiko Kohtake, Ryo Ohsawa, Takuro Yonezawa, Yuki Matsukura, Masayuki Iwai, Kazunori Takashio, and Hideyuki Tokuda Graduate School of Media and Governance, Keio University, Delta S213, Endo 5322, Fujisawa, Kanagawa , Japan nao/ Abstract. This paper introduces a novel way to allow non-expert users to create smart surroundings. Non-smart everyday objects such as furniture and appliances found in homes and offices can be converted to smart ones by attaching computers, sensors, and devices. In this way, non-smart components that form non-smart objects are made smart in advance. For our first prototype, we have developed u-texture, a self-organizable universal panel that works as a building block. The u-texture can change its own behavior autonomously through recognition of its location, its inclination, and surrounding environment by assembling these factors physically. We have demonstrated several applications to confirm that u-textures can create smart surroundings easily without expert users. 1 Introduction Owing to recent improvements in computer, sensor, and network technology, many non-smart objects are converted into smart objects by various approaches. These environmental smart objects such as smart furniture [1], smart rooms [2], smart homes [3], and smart buildings [4] are defined as smart surroundings and support human activities. However, it is difficult for users who are unfamiliar with computing technology to select and prepare the essential devices, to set them at appropriate positions, and to create and maintain smart surroundings without expert help. Our goal, therefore, is to develop technology that enables non-expert users to create smart surroundings easily. With this technology, anyone would be able to create smart surroundings anytime anywhere and to obtain a context-aware application. This research focuses on block materials that have uniform shapes to allow users to create various objects such as furniture, floors in homes, sidewalks outdoors, homes, or buildings by connecting or assembling them. There are many kinds of block materials such as bricks, panels, and tiles in our surroundings. As our approaches in developing the technology for non-expert users, we have been developing smart objects block materials in advance, not by converting existing non-smart objects to smart objects. Required operations for users are just to assemble the block materials in shapes suitable for what users wish to do. M. Beigl et al. (Eds.): UbiComp 2005, LNCS 3660, pp , c Springer-Verlag Berlin Heidelberg 2005

2 20 Naohiko Kohtake et al. The advantage of this system is that customization or calibration, which require computing skills, are unnecessary. Table 1 shows the examples of objects with block materials. Users can create various kinds of objects with each material. If each material becomes a smart one, such objects can provide context-aware applications corresponding to their shape. For example, if a ceiling or a floor is created with smart tiles, by recognizing users and their positions on the smart floor or by the smart ceiling, it will be possible to control appliances such as an air conditioner and lighting appropriately. Table 1. Examples of objects with block materials Until now, researches that aim to create smart surroundings without experts and researches that apply building block interfaces for creating context-aware applications have been investigated. The former researches [5, 6, 7] are mainly aimed at realizing each particular smart surroundings defined beforehand and enable users to create it with their physical interactions without expert help. In addition, the latter researches [8, 9, 10] recognize 3D structures of assembled blocks and enable users to create 3D modeling or tangible programming. This paper proposes u-texture, a self-organizable universal panel created beforehand as a smart building block material. Assembled u-textures create smart surroundings that have shapes such as shelves, tables, and walls, which correspond to assembled shapes. Figure 1 shows example of u-textures and how to create smart surroundings and context-aware applications by assembling them. In this case, u-textures are used as several smart surroundings for discussing and creating a logo design for our project. First, each u-texture is used as a drawing tool individually. Afterwards, users can connect their u-textures each other horizontally and exchange and merge their drawing data among connected u-textures by drag-and-drop operations. Finally, when the u-textures are assembled horizontally and set in vertical, users can look four candidates of drawing data on each u-texture at the same time and expand one of them on four u-textures. Once assembled in shapes, u-textures can autonomously provide suitable actions to the shapes by recognizing the shapes through exchanges of information on their connections and inclinations among each u-texture. Without

3 u-texture:self-organizable Universal Panels 21 knowing anything about electrical connections, users can assemble u-textures into smart objects practically and operate them to correspond to their assembled shapes. Table 2 shows a comparison of procedures for making smart surroundings with the typical electrical devices such as computers, sensors, and instruments, and with u-textures. Fig. 1. Example of u-textures and the assembly of smart surroundings Table 2. Comparison of procedures for making smart surroundings with the typical electrical devices and u-textures The sections of this paper are structured to make each point independently. After outlining u-textures in Section 2, this paper continues with describing thesystemdesigninsection3andthesystem architecture in Section 4, covers potential applications in Section 5, explains the user experience in Section 6, and finally discusses the advantages of using u-textures in Section 7. Section 8 describes past work related to u-texture and Section 9 concludes our current work and outlines future work.

4 22 Naohiko Kohtake et al. 2 u-texture 2.1 Concept To explain our purpose in this research, the main concepts of the u-texture are considered as follows: Easy Assembling A user can assemble u-textures easily without knowing the configuration with computers, sensors, and networks inside each u-texture. No specific tools are necessary for assembling u-textures. Self-Recognition As a user assembles u-textures, the assembled u-textures exchange information such as whether connected or not, connection directions, IDs of adjoining u-textures, and the u-textures inclination. With that information, each u-texture recognizes its assembled shape as well as its location and inclination in the assembled shape. Behaviors to the Shape Available applications corresponding to the shape of the assembled u-textures will be extracted automatically among multiple applications pre-installed in each u-texture. When there are several candidate applications to the shape, with minimum selection of the user, each u-texture behaves autonomously and runs the same application together. 2.2 Assembling u-textures Figure 2 shows a user assembling u-textures and establishing a shelf-shaped smart object: from top; A user assembles u-textures. The u-textures indicate application candidates corresponding to the assembled shapes. A user selects a desired application. The u-textures cooperate and run the selected application. 3 System Design Figure 3 shows an appearance of a u-texture (right). The prototype of u-texture is 320 mm square, 48 mm thick, and weights 4300 g. Every u-texture is designed to the same specification to enable users to assemble smart objects with any u- Textures. It costs more to equip full functions in all the u-textures than to install them with limited functions according to assembled systems. Since one of our purposes for developing this prototype is to confirm various potential advantages that u-textures can provide, we designed sensors and networks redundantly. The u-texture should have a structural function possible to be assembled and an electrical function possible to be connected electrically. In the current version, a blockable prop, u-joint (Figure 3, left), supports to assemble u-textures.

5 u-texture:self-organizable Universal Panels 23 Fig. 2. Sequence in creation of a shelf-shaped smart object 3.1 Structures to Be Assembled The u-texture is designed with a reasonable size and strength to be able to create furniture like tables and shelves; the u-texture is also designed for easy assembly in various forms as furniture as a square-shaped plate, which is a basic component shape. A connecting structure is required to assemble one u-texture and another one, and the connections can be implemented both horizontally and vertically. To create an easy-to-assemble system for every user, the u-texture and the u-joint are designed to have a simple structure for connections. 3.2 Interactions with Other u-textures and Users We consider it is appropriate that each u-texture has its own computer and battery to be able to work autonomously. It is necessary to assign connection sensors on each of the four sides of u-texture, so that the u-texture can determine whether it is connected to another u-textures or not and its direction if connected, as well as obtain the IDs of the connected u-textures. It is essential to include electrical connectors in the structural connectors which support u-textures to create electrical connections physically connecting. An inclination

6 24 Naohiko Kohtake et al. Fig. 3. A u-texture (right) and a u-joint (left) sensor is required for the u-texture to recognize itself. The connection sensor data and the inclination sensor data are essential that a u-texture recognizes its assembled shape, and location and inclination in the assembled shape. It is necessary that the both data is shared together. The two kinds of sensor data are categorized into the global sensor data. Proximity sensors will be assigned on its four sides in order to recognize neighboring u-texture s IDs and their directions. Sensors such as RFID tag readers that can discriminate between u-textures, objects and users are useful. Interactive touch panels and mikes are also effective because users can interact with u-textures without input devices. These sensor data which are used in each u-texture inside are categorized into the local sensor data. In this prototype, two kinds of networks are used individually to avoid network congestion. A wired network exchanges data among the assembled u-textures internally, and a wireless network exchanges data among other smart objects. 3.3 State Transition Figure 4 shows a state transition diagram of u-texture. The state sequentially moves through five layers of states: Initialized, Recognized, Application Wait, Application Ready, and Application Running. When a u-texture detects a change in global or local sensor data, the state will be moved to the Ready to Detect state. Then, when the u-texture receives the shutdown command from a user, the state will be moved to the Ready to Shutdown state at all time. Each state in the state transition diagram is described as follows: Initialized: u-texture initializes all systems. Recognized: u-texture recognizes the assembled shape with the other u-textures and each location and inclination of the assembled u-textures. Application Wait: u-texture extracts the available applications corresponding to the shape of the assembled u-textures.

7 u-texture:self-organizable Universal Panels 25 Fig. 4. State transition diagram Application Ready: u-texture is ready to run the available applications and indicates a list of them to users. Application Running: u-texture runs the application selected by a user. Ready to Detect: u-texture is ready to detect global or local sensor data. In case of global sensor data, both changes that occur internally or externally are sent to the Recognized state. In this case, internal data refers to the change within the system and external data refers to the change of assembled u-textures. On the other hand, when local sensor data of internal sensors is detected, it is sent to the Application Running state. Ready to Shutdown: u-texture prepares to shutdown all systems. Shutdown: u-texture shuts all systems down. 4 System Architecture 4.1 Hardware Sensing Capability Figure 5 shows a block diagram of the u-texture and the u-joint. Each side of the u-texture and the u-joint is equipped with an RS-232C interface as a connection sensor examines whether the u-texture is connected to other u-textures or not, and its direction if it is connected. The 3D sensor is used to obtain inclination data. The sensor is created with two dual axis accelerometers (ADXL202, Analog Devices). Infrared sensors are located on each side of the u-texture as a proximity sensor, and are used to detect nearby or incoming remote u-textures. All sensors outputs mentioned above are processed by a microcontroller (H8/3664F 16MHx, Hitachi). The microcontroller dispatches the network ID of the u-texture and the network IDs of the connected u-textures located on its sides. The microcontroller can also simultaneously receive the same data from connected u-textures, and then send the data to the main computer to have the data processed.

8 26 Naohiko Kohtake et al. Fig. 5. Block diagram of the u-texture (right) and the u-joint (left) Computing and Networking Capability The main computer consists of the Mobile Pentium processor, a speaker, an IEEE b wireless network and display (SXGA 14.1type). All are parts adapted from a laptop computer (CF-Y2DM1AXR, Panasonic). A tough panel (AST-140, DMC) enables direct inputs. An RFID tag reader/writer (13.56MHz, Sofel) is embedded and antennas are built-in around the display. Ethernet interfaces are also implemented on each side of u-texture. The basic idea behind a wired network for exchanging data among the assembled u-textures internally is to create an extemporaneous bridge network with broadcast support and loop back prevention. This is accomplished by binding each Ethernet interface into one pseudo network device, and binding an active network ID to the device. With additional help from a loop back prevention protocol, the packet storming within the network can be reduced. The detailed design is described in our other paper [11]. u-joint The u-joint provides power to connected u-textures. The RS-232C and Ethernet interfaces are built into the u-joint to transmit and receive data between u-textures. Structural Interface The u-texture is defined with directions of up and down, and left and right physically as shown in Figure 3. u-joint is also defined up and down. To simplify the automatic structure recognition by the software, there are three assembly regulations as follows. (1) u-texture should be assembled to others horizontally or vertically via u-joints. (2) The surfaces of the u-textures should be connected with the same directions when assembling them horizontally. (3) The top of the u-texture should be connected to the bottom of the other u-texture and the right side to the left side. The structure of the u-texture has an original connecting mechanism to make users unconsciously adhere to the regulations.

9 u-texture:self-organizable Universal Panels Software A block diagram of software module is shown in Figure 6. The software module consists of three modules pre-installed in each u-texture: the Event Sharing Module, thestructure Recognition Module, andtheapplication Launcher Module. TheApplication Module is created and installed by developers, and runs one application. Each Application Module has the Application Description Data (hereinafter AD Data ) which describes the minimum structure data that the application can be executed. Fig. 6. Block diagram of software modules Recognition Phase The Event Sharing Module obtains global and local sensor data from all sensors (Figure 6, No.1), exchange the global sensor data with all assembled u-textures (Figure 6, No.2) and sends all the global data to the Structure Recognition Module (Figure 6, No.3). The Structure Recognition Module recognizes the structure of u-textures with the exclusive coordinates for u-textures. The global sensor data consists of the connected or disconnected status of four sides, each ID of the connected u-textures, and inclination data. Figure 7 shows an example of global sensor data which describes that the lower edge of u-texture A is connected with u-texture B and u-texture C. The part A of Figure 7 describes that the ID of u-texture A is , which is its own IP address. The u-texture A is connecting with others on the lower edge, and the inclination of the u-texture A is vertical. The part B of Figure 7 describes the IP address, the connected edge, and the inclination of the u-textures connected with the lower edge of u-texture A. The coordinates definition on assembled shape, location, and inclination of u-textures is shown in Figure 8 (left). Each corner of u-texture has a number

10 28 Naohiko Kohtake et al. Fig. 7. Example of global sensor data of coodinates. Figure 9 shows an example of re-calculation of the u-texture C. When the u-texture C does not connect to other u-textures, the number coordinate at the bottom left corner is always (0, 0, 0) (Figure 9, left). When a u-texture assembles with other u-textures, all assembled u-textures re-calculate its own coordinates and the assembled shape individually. A position and inclination of eachu-textureis describedas {(bottom left corner s coordinate), quadrant}. Before connection, the bottom left corner of each u-texture is (0, 0, 0). Primarily, if there are some u-textures which stand horizontally in the assembled u-textures, the bottom left one is determined as {( ), QuadXY}(Figure 9, left). Secondarily, if there are no horizontal u-textures, the bottom left u-texture which stand vertically is determined as {(0, 0, 0), QuadXZ}. The u-texture C is {(0,0,0),QuadXZ} and the u-texture D is {(0, 0, 0), QuadXY} before connection (Figure 9, left). After connection, the u-texture C starts re-calculating with considering the bottom left corner as the starting point (Figure 9, center). Finally, if there are minuses in the coordinates of the assembled u-textures, all coordinate is shifted to change the minuses to pluses or zero (Figure 9, right). After re-calculation, the u-texture C results the coordinates of the assembled u-textures as unique coordinates and recognizes their structures of them. Adaptation Phase When the Application Launcher Module receives the recognized structure data (Figure 6, No.4), it acquires the AD Data from each Application Module (Figure 6, No.5). Afterwards, the Application Launcher Module extracts available applications by comparing the AD Data with the recognized structure data. If the recognized structure includes a minimum structure described in an AD Data, the application will be considered an available application. Figure 10 shows a DTD of the AD Data in XML format. The available-condition shows the minimum data structure and has three attributes. number shows the total number of the minimum structure, form

11 u-texture:self-organizable Universal Panels 29 Fig. 8. Coordinates definition(left) and coordinates of shelf-shaped object(right) Fig. 9. Example of re-calculation of u-texture C shows the assembled form, and inclination shows the inclination that at least one u-texture is set. form has three definitions of the assembled form. sequential means the minimum number of u-textures are on the same plane and have a sequential connecting part, cross means they have a rectangular connecting part, and square means they are on the same plane and set squarely. Figure 11 shows an example of an application description data. In this case, if the assembled u-textures have a rectangular connecting part and one of them is set on the QuadXY, the Application Launcher Module will extract this application as an available application. When the assembled u-textures are in complicated forms, various available applications will be indicated to users in this case. In this prototype, we take priority not to indicate unavailable applications to users without fail because we consider that the desired application is different depending on users even though they assemble the same structure with u-textures. After extracting available applications, the Application Launcher Module exchanges the list of them with all other assembled u-textures (Figure 6, No.6) and merges the lists into the one list. Finally, the list is indicated to users (Figure 6, No.7).

12 30 Naohiko Kohtake et al. Fig. 10. DTD of AD Data Fig. 11. AD Data Example Cooperation Phase When the Application Launcher Module receives a selection command and a start command of the available applications from a user (Figure 6, No.8), the module broadcasts the commands to the same modules of other u-textures (Figure 6, No.9). Afterwards, the Application Launcher Module sends a start command to the Application Module of a selected application (Figure 6, No.10). Application Modules of u-textures run the selected application and cooperates together gradually (Figure 6, No.11). Each Application Module receives local sensor data periodically (Figure 6, No.12) and changes the u-texture s behavior corresponding to the data. The functionality of the main body of the Application Module is described in pseudo code in Figure 12. The invocation received by getevent is processed according to the type of the sensor event. Structure Event monitors the structural data of the assembled u-textures, Connection Event and Inlination Event monitor the events of each global sensor data of the all assembled u-textures, and RFIDtag Event and IRsensor Event monitor the events of each local sensor data of the u- Texture. Each application is described in appropriate parts in each Application Module. To develop a new application, it is necessary to make both a new Application Module and a new AD Data. 5 u-texture Based Smart Surroundings We have implemented eleven context-aware applications to confirm the effectiveness of u-texture. Some of the applications are described in the following subsections. 5.1 AwareShelf The AwareShelf can be created on a shelf-shaped u-textures as shown in Figure 2. When a user puts a real object such as a camera, a book, or a key on a u-texture, it enables to browse information of the real object on the display on another u-texture. The u-textures have to be connected vertically to the

13 u-texture:self-organizable Universal Panels 31 Fig. 12. Main body of Application Module u-texture on that a thing is placed. For example, a user can check an electrical manual of a camera, or duration of times that a key was put on the AwareShelf before. In this application, real objects are attached unique RFID tags and u- Texture recognizes the tag IDs. When the AwareShelf connects to an external network, a user can look for real objects. Currently, the advanced application has been implemented so that a user can find the AwareShelf on which the real object was placed by using a mobile phone. In this application, the AwareShelf is used as a system for storing and recognizing objects (Figure 13). Fig. 13. AwareShelf 5.2 CollaborationTable The Collaboration Table is a system that supports cooperative work with several participants by connecting u-textures horizontally as shown in Figure 14. Users can exchange and merge drawing data among connected u-textures by drag-and-drop operations. One advantage of this application is that it is possible to expand users creative ideas and collaborations in cooperative works. Another advantage is that it is possible to use a u-texture both privately and publicly by connecting a u-texture or setting it closer to another u-texture.

14 32 Naohiko Kohtake et al. Fig. 14. CollaborationTable 5.3 ProjectionWall The ProjectionWall magnifies a connected u-texture s small display onto a big one as shown in Figure 15. It is effective for displaying a large picture that is too small to be shown on only one u-texture. Data can be handled interactively by users with touch panels. Although the similar interactive large display can be created with projectors, users have to establish or attach computers, sensors connected to the projector and to calibrate them. Converting coordinates for magnifying data is implemented by automatic cooperation among u-textures, which can be one of the advantages for application developers and non-expert users in the respect that it is not necessary to be aware of changing coordinates. Fig. 15. ProjectionWall 6 User Experience Before implementing the current version of u-texture, we have developed two earlier prototypes and conducted preliminary investigations. In this version, we have implemented sixteen u-textures and eleven applications. The u-textures have been placed in a demonstration room of our university and exhibited at several conferences and symposiums. Many people have tried assembling and dismantling u-textures in practice. During the experience, interesting user reactions were observed and many opinions and comments were received.

15 u-texture:self-organizable Universal Panels Advantages of u-texture Several applications can share data externally in the current version. Some people tried a task such as making design drawings with multiple applications using the same u-textures as shown in Figure1. As the progress of the task, users could modify their smart surroundings by changing the assembled shape of u-textures. Most users who had experiences of such usage liked this advantage. Without u- Textures, the data exchange among several smart surroundings is also possible via a network. However, some users, especially for non-experts, commented that changing smart surroundings by physical interactions was intuitive and acceptable. Availability of multiple smart surroundings with the same u-textures was also welcomed. 6.2 Features in Assembling The idea that the shape of u-textures is recognized automatically by physical assembling them was accepted favorably. Many users commented that it was not necessary to be aware of electrical connections to assemble u-textures. However, since both physical and electrical connections require u-joints, users found it troublesome to assemble u-textures. We had an opinion that the prop of u- Texture is too thick, which would reduce the advantages of u-textures for using some applications such as the ProjectionWall. Now, we are modifying structures for assembling in the next version of u-texture. In this version, u-joint will be not necessary for assembling 2D objects such as a board and a wall. 6.3 Indication of Available Applications Corresponding to the Shape The approach to indicate available applications according to the shapes of u- Textures was well received by users. There was sometimes a comment that indicating list of application candidates corresponding to the shapes of u-textures was both enjoyable and stressful. It also seems suitable for users to indicate candidates of the final shape by users selecting applications in advance. 7 Discussions This research is still in an early phase, and we are considering several research issues and possible future directions. 7.1 Application Domain One promising area of the u-texture is to be used at homes, in offices, and at schools. In the case of using u-textures in classrooms, there will be many collaborative works or presentations among students. In fact, we have tried some collaborative tasks and confirmed the potential advantages. We also see a future

16 34 Naohiko Kohtake et al. of our system in home usage, because of the increase in assemblable modular furniture which allows free adjustment of its size. Business shows and conferences are also one of our targets. Users can assemble various interactive booths as smart surroundings easily and quickly. 7.2 Other Types of Smart Block Material The shapes and sizes of smart block materials are not limited to panels. Users can create many kinds of smart objects with various materials as shown in Table 1. The objects can provide applications corresponding to the features of the material. When designing any smart block material, it is essential for non-expert users to include electrical interfaces in the structural interfaces of the block materials. The design for maintaining and debugging corresponding to each material is also considered. 7.3 Extraction of Available Application In this current prototype, each application defines executable shapes with only several primitive shapes based on three parameters. The available applications are extracted if the assembled u-texture includes the executable shapes the applications defined. The selection mechanism was appropriate for assembling sixteen u-textures and using about eleven applications. However, when users assemble many u-textures and use a number of applications, the finer, more flexible and exhaustive definition toward all possible structures will be necessary. The definition should be elegant for application developers and we are investigating the novel definition now. 7.4 Re-design for Practical Use To apply u-textures for practical use as well as normal panels, several re-designs are desired. First, electrical system should be sophisticated and the next version will have the minimum configuration which can keep the advantage of u-texture. For instance, network capability creates internal and external communications with only a wireless network. Second, a spacer module which has the same structural capability as a normal u-texture is effective for huge assembled surroundings. The module has only a network capability as a connecter among u-textures. Structural strength and error indication and handling for software are also necessary for various uses and considered for the next version. Colors, exteriors, and balance with surroundings are important points for users to select objects such as furniture and appliances, and we are also investigating this matter. 8 Related Work Our inspiration for using building block materials as furniture came from the square paper tubes and panels of MUJI [12] which can form various furniture such as racks, tables, and stools.

17 u-texture:self-organizable Universal Panels 35 Researches that enable users to create smart surroundings easily have been already pursued. Most of them create it with physical interaction of the system, such as connecting, bumping, and setting without experts. ConnecTable [5] is a table that has a display embedded in its surface. ConnecTable can be used a personal display and a part of public display by attaching physically two tables. Ken Hinckley s multiple tablet computer system [6] can also form dedicated connections by physically bumping together displays with their distributed sensors. Impromptu [7] is a concept that allows users to create smart surrounding without set-ups, maintaining or administering. It enables to build such environments rapidly with autonomous cooperation of consumer appliances. Compared to the above systems, the advantage of u-texture is that it can recognize assembled shapes and autonomously extract appropriate context-aware applications corresponding to the shape. Researches on building blocks with embedded computations have been carried out until now. However, their target users and applications are different from our research and most of them enable the recognition of 2D structure only. Algo- Block [8] is an educational system of cubical aluminum blocks for programming by docking each other on a table. Triangle [9] is a tangible programming system of a triangular shaped block. The three sides are connected with a joint with an electrical joint, and can recognize the entire shape. Both of above systems show the entire shape on a display of a remote computer and enable users to control the data with physical operation of the building blocks. Computational Building Block [13] is also an input device for structuring information. The target application of the system is 3D geometric modeling with 3D structure recognition. DataTiles [10] is a system which changes its function by re-arranging tiles with built-in RFID tags with displays with build-in computers. As sample applications, sending , editing pictures, and operating home appliances are created corresponding to the combination of the DataTiles on the plat-panel display with RFID tag readers. Mostly, these systems are made to have fixed executable applications beforehand. In case of u-texture, it collaborates with other ones by autonomous according to the 3D structure of u-textures. 9 Conclusions and Future Work This paper has contributed a smart building block as a self-organizable universal panel that allows non-expert users to create smart surroundings. The assembled u-textures create smart surroundings that have shapes of every day objects such as shelves, tables, and walls without experts. Then, the smart surroundings are utilized as systems for supporting various activities of each user or for cooperative works among multiple users. The effectiveness has been confirmed by introducing several applications using the u-texture and conducting user experiments. We are also interested in implementing smaller and bigger versions of smart building blocks with other types of material. Users can assemble other smart building blocks and create many context-aware applications in various situations. We believe the smart building blocks will be one of the standard ways for creating smart surroundings.

18 36 Naohiko Kohtake et al. 10 Acknowledgements This research has been conducted as part of Ubila Project supported by Ministry of Internal Affairs and Communications, Japan. We would like to express our appreciation to Keio Ubila team and Uchida Yoko Co.,Ltd. for supporting this research. And thanks to the reviewers for helpful suggestions and comments. References [1] Tokuda, H., Takashio, K., Nakazawa, J., Matsumiya, K., Ito, M., Saito, M.: Sf2: Smart furniture for creating ubiquitous applications. In: International Workshop on Cyberspace Technologies and Societies (IWCTS2004). (2004) [2] Streitz, N., Tandler, P., Muller-Tomfelde, C., Konomi, S.: Roomware: Towards the next generation of human-computer interaction based on an integrated design of real and virtual worlds. In: HCI in the New Millenium. (2001) [3] Kidd, C.D., Orr, R., Abowd, G.D., Atkeson, C.G., Essa, I.A., MacIntyre, B., Mynatt, E.D., Starner, T., Newstetter, W.: The awarehome: A living laboratory for ubiquitous computing research. In: Cooperative Buildings. (1999) [4] Snoonian, D.: Smart buildings. IEEE Spectrum 40 (2003) [5] Tandler, P., Prante, T., Muller-Tomfelde, C., Streitz, N.A., Steinmetz, R.: Connectables: Dynamic coupling of displays for the flexible creation of shared workspaces. In: Annual ACM Symposium on User Interface Software and Technology (UIST 01). (2001) [6] Hinckley, K.: Distributed and local sensing techniques for face-to-face collaboration. In: Fifth international conference on Multimodal interfaces (ICMI 03). Volume (2003) [7] Beigl, M., Zimmer, T., Krohn, A., Decker, C., Robinson, P.: Creating ad-hoc pervasive computing environments. In: Pervasive 2004 Advances in Pervasive Computing. (2004) [8] Suzuki, H., Kato, H.: Interaction-level support for collaborative learning: Algoblock an open programming language. In: The first international conference on Computer support for collaborative learning (CSCL 95). (1995) [9] Gorbet, M.G., Orth, M., Ishii, H.: Triangles: Tangible interface for manipulation and exploration of digital information topography. In: The SIGCHI conference on Human Factors in Computing Systems (CHI 98). (1998) [10] Rekimoto, J., Ullmer, B., Oba, H.: Datatiles: a modular platform for mixed physical and graphical interactions. In: The SIGCHI Conference on Human Factors in Computing Systems (CHI 01). (2001) [11] Yanagihara, T., Sakakibara, H., Ohsawa, R., Ideuchi, M., Kohtake, N., Iwai, M., Takashio, K., Tokuda, H.: A self configurable topology-aware network for smart materials. In: Fifth IEEE International Workshop on Smart Appliances and Wearable Computing (IWSAWC2005). (2005) [12] MUJI: ( [13] Anderson, D., Frankel, J.L., Marks, J., Agarwala, A., Beardsley, P., Hodgins, J., Leigh, D., Ryall, K., Sullivan, E., Yedidia, J.S.: Tangible interaction + graphical interpretation: a new approach to 3d modeling. In: 27th annual conference on Computer graphics and interactive techniques (SIGGRAPH 00). (2000)