Mitsunori Matsushita

Tablescape Plus: Interactive Small-sized Vertical Displays on a Horizontal Tabletop Display

This paper proposes a novel paradigm: human-centered tabletop computing, which enhances the role of an ordinary table by projecting interactive images onto tabletop objects and the table surface at the same time. The advantage of this approach is that it utilizes tabletop objects as projection screens as well as input tools. As a result, we can change the appearance and role of each tabletop object easily and fulfill two important requirements of tabletop tangible interfaces, identifiability and versatility, which have proven difficult to satisfy simultaneously in previous systems. Our prototype, tablescape plus, achieves these functions by using two projectors and a special tabletop screen system that diffuses or transmits images selectively according to the projection orientation. This paper presents the design principle, optical design, and implementation of tablescape plus. Furthermore, we introduce several interactive applications.

Lumisight table: interactive view-dependent display-table surrounded by multiple users

Lumisight Table is not just an interactive display technology. Now, you have a new canvas. You can display anything, and design new interactive applications on it. The possibilities are unlimited: entertainment, computer supported cooperative work, networked applications, and media art works. In order to realize Lumasight Table, we will implement an application program interface in the near future.

Behavioral analysis of asymmetric information sharing on Lumisight table

This research reveals the factors important in designing a group support environment by focusing on a distributed cognitive environment where group members have different information. We find that closeness within a group enhances group performance when group members use a tabletop CSCW environment. To confirm this, we conduct experiments that observe human behavior in a distributed cognitive environment. Participants play a maze game in which players with restricted and distributed information communicate with each other to catch a rapidly moving target. Group performance in two CSCW environments was compared: a normal LCD setup that prevented indirect communication and a tabletop display, Lumisight table. Group performance was found to be higher with the tabletop display, and the performance advantage was reinforced by the closeness of the group members.

Criteria to choose appropriate graph-types

Results from empirical studies on automatic visualization systems for statistical data are reported. These studies especially focused on a mechanism for choosing an appropriate graph type. Two experiments were conducted as a first step fowards proposing a mechanism with objective bases.

Answering it with charts: dialogue in natural language and charts

A methodology is proposed for taking queries and requests expressed in natural language as input and answering them in charts through organizing that interaction into felicitous dialogue. Charts and graphics, as well as languages, are important modes of communication. This is especially true of those which are used frequently when people analyze huge amount of data interactively, in order to find out its characteristics or to resolve questions about it. This paper raises the problem that in such situations the correctness of the charts depends on the context, and proposes a framework to resolve it. The core of the framework is a logical form that includes the specifications of the users perspective and the proper treatment of the logical form for handling utterance fragments. The framework has been implemented and confirmed to be appropriate.

A visualization method of time expressions using starting/ending point plane

The authors propose a method that visualizes the time transitions in written time expressions in order to analyze how the author used them. The method represents time expressions as points on a plane and connects them with lines. They apply the method to an adventure story and a company history and discover two characteristics. First, during the progression of the text, the durations implied by the time expressions change from long to short. Second, at the start of a new paragraph, expressions tend to refer to events or periods of longer duration.

Interactive visualization method for exploratory data analysis

We propose an interactive visualization method suitable for exploratory data analysis. In this type of data analysis, statistical charts are employed to help the user understand the target data, and a displayed chart is redrawn interactively according to the users input inspired by looking at the chart. Two factors must be considered if the chart is to be suitably redrawn: the type of chart displayed and the parts of the chart that are changed by the users input. We developed our proposed method based on these factors. As the first step of the method, the part to change and the details to meet the given users input for the displayed chart are interpreted. Then, a semantic frame used to generate a statistical chart from data is updated by the results of the interpretation, and several candidates as appropriate chart-types are chosen based on the frame and chart-type determination rules. Finally, the most preferable chart is chosen from among the candidates according to the type of user input, and the displayed chart is transformed into a new chart with animation. By using this method, data can be visualized interactively according to the change of the users viewpoint without interrupting the thinking process.

A Fast Pattern-matching Algorithm Using Matching Candidates for Production Systems

Several fast pattern matching algorithms have been proposed to improve the inference speed of production systems. In almost all of these algorithms, conditions in rules are represented using a dataflow network and working memory elements propagates this network as tokens. These algorithms are effective, but excessive constant testing is unavoidable when the working memory must be frequently updated.

Constructing knowledge using exploratory text mining

Our goal is to support users who want to discover or create knowledge from a large amount of text data. Text mining is a process that extracts novel knowledge from unstructured data. A variety of applications for text mining, such as Total Environment for Text Data Mining, have been proposed. However, to the best of our knowledge, these methods are not effective at conducting text mining tasks aimed at finding novel knowledge. In this paper, we discuss characteristics of the text mining process and propose a design principle for building text mining applications based on two concepts: (1) text mining is an exploratory search task, and (2) text mining is a process for creative knowledge work.

Supporting exploratory data analysis by preserving contexts

The goal of the research presented in this paper is to support users in exploring a huge amount of data for the purpose of decision-making and problem-solving. Our approach is to design human-computer interaction as a natural discourse between the user who explores the data and the system that supports the users exploration process. For that purpose, we developed a prototype system named InTREND that interprets the users natural language query and presents statistical charts as a result of the query. InTREND encourages iterative exploration by maintaining the context of past interactions and uses this context to improve discourse with the user. This paper explains our research motivation and presents a framework for supporting exploratory data analysis. Our user studies evaluate the context preservation mechanisms of InTREND.