In this research, the authors succeeded in creating facial expressions made with the minimum necessary elements for recognizing a face. The elements are two eyes and a mouth made using precise circles, which are transformed to make facial expressions geometrically, through rotation and vertically scaling transformation. The facial expression patterns made by the geometric elements and transformations were composed employing three dimensions of visual information that had been suggested by many previous researches, slantedness of the mouth, openness of the face, and slantedness of the eyes. The authors found that this minimal facial expressions can be classified into 10 emotions: happy, angry, sad, disgust, fear, surprised, angry*, fear*, neutral (pleasant) indicating positive emotion, and neutral (unpleasant) indicating negative emotion. The authors also investigate and report cultural differences of impressions of facial expressions of above-mentioned simplified face.

Recently, it has become more and more important to learn foreign languages for business or personal interests. However, it is not easy to increase the vocabulary of foreign languages, as it requires a lot of time to learn many new words. In this paper, we propose a smartphone application named FinDo which presents a vocabulary list related to the place that the user is located at. By utilizing short periods of time during the user's daily activities, FinDo allows users to comprehend the meaning of unfamiliar words in the most efficient manner with the context related to their own location. For example, when a user is in a supermarket, he/she can learn all the related words of surrounding objects there. We held an experimental evaluation to compare the proposed system with a system without the location-context content with two groups. The experimental results show that the group using FinDo were able to improve, although no significant difference can be seen between the two groups. However, the group using FinDo found it more entertaining and appealing.

With the development of Web 2.0 technology, Q&A websites have become one of the most common avenues for large scale knowledge sharing. However, three types of barriers between questioners and respondents make knowledge sharing difficult:differences in the personality types of the questioners and respondents, lack of trust, and an arrogant or negative attitude exhibited by some questioners. In order to lower these barriers, we propose a Q&A mediator system with virtual character agents. In this system, a questioner asks questions through his/her own agent, and the respondents see the question from their agent. Each agent has four characteristics:personality traits similar to knowledge sharers, good looks, affable personality, and a positive attitude. The results of a preliminary experiment indicated that the proposed system can improve the users' motivation to answer questions.

Together with the development of Web 2.0 technology, we need to focus more on large-scale knowledge sharing. Owing to the characteristics of the long-tail distribution generally observed in conventional knowledge-sharing systems, knowledge providers are sometimes unwilling to share knowledge when they are unable to obtain any feedback. However, when knowledge acquirers read long-tail knowledge, they may easily feel bored because such knowledge rarely matches their own interests. To solve these problems, we proposed and implemented a gamified knowledge-sharing system called "Light Quest," which can share long-tail knowledge in an entertaining way. In this system, the users can briefly describe knowledge they would like to share using a "Tips Card," and evaluate the cards written by other users, by choosing the best card from a set of cards that are randomly selected from a knowledge pool. The results of a four-week experimental evaluation indicated that the system could increase users' motivation to both provide and acquire knowledge.

Usually we have to queue in cafeterias until our turn. In such situations, we often feel bored because we cannot do anything to pass time while queuing. In order to solve this problem, we are introducing entertainment system using music co-creation for situations comparable to queuing in cafeterias. In this paper, we propose a rhythmic music co-creation system using cafeteria trays, named "TipTapTrays." In a cafeteria, it is natural for people to hold a tray. Users can naturally and easily make sounds to co-create music by shaking or tapping each tray while queuing. Having evaluated TipTapTrays, we found that the boredom of having to queue could be avoided by using TipTapTrays to play music.

People often ignore their reminders or schedulers, which notify them about their requisite tasks using monotonous message expressions, usually because they do not pay sufficient attention to their notifications and they feel that they are under no pressure to respond. In this study, we propose a notification design method that uses mother-like expressions to enhance user acceptability of notifications. Mother-like expressions are highly variable, such as euphemistic expressions and imperative forms, and notifications that use them may apply different levels of pressure on users. To implement a reminder system that provides notifications regarding various tasks using mother-like expressions, we classified tasks collected from actual reminders, schedulers, and diaries. As a result, we found that the tasks could be classified into six verb-based categories, which could be adapted using mother-like expressions.

Most of traditional retrieval keys are the place (folder), name and content of desired files. If a user does not remember these keys, it is difficult for him or her to access desired files. In order to solve this problem, we propose a file retrieval system that is based on provenance. In this paper, provenance means the history of the file's moving and editing that a user has experienced. By recording how and from where a user gets the file, the system enables the user to query, for example, "which files did I get from my teacher yesterday?", "which files did I download from the web page of my college last month?", and "which files did I edit by MS Word last week?" We present a model of provenance and describe how to use provenance as the keys of retrieval and how the system is constructed.

Computer-aided design (CAD) system conventionally have been widely used to support designers for creating, modifying, adding something to or removing something from objects by showing simulated objects on computer screen. These virtual, non-physical, objects have been, however, known as imperfect imitation of reality. The impression of shape is highly related to the second order derivative of geometric feature of the shape. Conventional CAD systems, including AutoCAD, usually have visualization feature of the first derivative (normal) and the second derivative (curvature) of given surfaces. There, however, still have been problems in curvature visualization on the screen. First, it lacks true feeling of physical objects. Second, even if designers were given a physical mock-up object in hand, they wouldn't precisely recognize minute change of curvatures — few designers can sense small differences of curvature and most others need a special device to check the curvature. For solving these problem, the authors propose a novel curvature visualization system based on mixed reality technology. The color mapping according to the Gaussian curvature calculated via a time-of-flight camera provides the observers with intuitively understanding the object's curvature information.

This paper presents a novel mixed reality (MR) system for virtually modifying (e.g., denting, engraving, swelling) shape of real objects by using projection of computer-generated shade. Users of this system, which we call HYPERREAL, perceive as if the real object is actually being deformed when they operate the system to modify the shape of the object while only the illumination pattern of the real object is changed. The authors are aiming to apply this technology to product designing field: designers would be able to evaluate and modify form of their product more efficiently and effectively in an intuitive manner using HYPERREAL than conventional design process (typically, computer aided design, or CAD, systems and solid mock-ups) since the system is able to provide users with actuality/presence of real mock-up and flexibility of shape data on a computer system, such as CAD system, all at once.