The spread of Video on Demand (VOD) services is driving the creation of video viewing environments in which users can watch whatever they like, whenever they like. The recent appearance of social network services (SNSs), moreover, is bringing big changes to the world of media by enabling anyone to become a disseminator of information. At NHK, Japan ' s public broadcaster, we are studying a platform that combines VOD and SNS to create "horizontal links" between program viewers and facilitate encounters with new programs. To investigate the requirements for this platform, we built a SNS site called "teleda" that enables program viewing by VOD and conducted a large-scale, three-month verification trial with about 1000 participants. We report on the features of viewing behavior obtained from the results of this trial and discuss the potential of public broadcasting services that combine VOD and SNS.

On-demand services for TV program, which provide users with past programs on demand, are becoming popular. It is therefore necessary to find a means of efficiently searching for programs that users want to view, from huge program archives. This paper proposes an automatic method of retrieving programs related to the one being viewed by the user. To that end, we compute similarity between program summaries and closed captions obtained from broadcasting by weighting significant words such as compound words and named entities. Additionally our method provides inter-program relationship labels to indicate why the results of relevant programs were chosen. The results of an evaluation showed that the method recommended relevant programs with higher accuracy than baseline methods and indicated appropriate relationship labels for related programs.

Here, we propose a technique to acquire knowledge for baseball digest video production using an inductive inference approach. We integrated the concept of inductive logic programming (ILP) and baseball game metadata to enable learning of the highlight scene definition from digest video produced by a TV director.ILP is a learning method formed at the intersection of machine learning and logic programming, and ILP processor can acquire the highlight scene definition by inductive learning from scenes that are selected as highlights in sports news. This technique makes it possible to generate a semantic digest automatically, which includes not only score scenes but also attractive scenes reflecting the director's intention.

Aiming to close the digital divide in the television viewing environment, we are developing a TV system with an agent that controls the TV and peripherals on behalf of the user and provides information to the user. We propose a TV system function that answers viewers' questions about TV programs by calling upon multiple question-answering agents that search for relevant information.

The authors propose the force control of a robot manipulator without a force sensor. The proposed force control system is realized by both the acceleration controller and the force observer. Both systems are designed by the mixed-sensitivity H/sup infinity / design method. The acceleration controller regulates the actuator of the robot manipulator by the acceleration control command. The force observer estimates the reaction force from the target environment. The experimental results showed that the response of the proposed force control system without a force sensor coincided with that of the force control system with a force sensor.>