To guarantee Quality of Service(QoS) for real-time applications strictly, we have proposed an output buffer control mechanism in IP routers, confirmed its effectiveness through simulations and implemented a prototype. This mechanism can guarantee QoS strictly within single router. In this paper, we propose the control scheme of mutual cooperation between IP routers equipped with the above-mentioned mechanism by using one of the signaling protocols. Our proposed scheme aims to stabilize End-to-End (E2E) delay of a flow within target delay. Also, reserved resources are dynamically updated between IP routers with our mechanism to improve E2E packet loss rate. We perform the implemental design of our scheme and empirical evaluation through the implementation. As one of results, we validated quantitatively that our scheme improves the quality of video picture.

Various real-time applications are widely used with the development of network infrastructure. To guarantee QoS(Quality of Service) of these applications strictly, the Internet will require a flow-based priority control. Thus, we have proposed an output buffer control mechanism. In this paper, to guarantee End-to-End QoS maximally by exploiting the buffer control mechanism, we propose the method of mutual cooperation between IP routers equipped with our mechanism by using one of the signaling protocols. In addition, we show the effectiveness of our proposal by computer simulation.

With the rapid increase of the traffic demand in the Internet, it is necessary to provide a priority control mechanism in the Internet router in order to realize suitable transmission for various attributes of multimedia traffic. Therefore we have proposed the output buffer control mechanism by flow management, and hardware implementation is performed as a basic design. This implementation has only the basic functions. In this paper, we expand our implementation to realize the advanced QoS guarantee. Concretely, we propose and implement the two ideas, "correspondence to variable length packets," and "correspondence to multiple ports".

We focus on content delivery services using erasure codes. By using erasure codes, reliable content distribution can be performed without multi-server scheduling. Thus, for the efficient use of network resources, we propose dynamic rate control adapting to the change of the network conditions for multi-server content distribution.

Recently, various applications have emerged with improvement of the speed and capacity of the Internet. In the future, various types of traffic will co-exist. Thus, it is required to guarantee QoS suitable for the attribute of each traffic. So far, to realize QoS guarantee per flow, we have proposed a class-based output buffer control mechanism, based on autonomous flow management. However, it guarantees only the bandwidth. We expand the function of this mechanism to guarantee delay, jitter and bandwidth. In addition, we show the effectiveness of our proposal by computer simulation.

The paper describes a retrieval technique for video databases that is based on gestures. The proposed technique gives users a method to create various video content by intuitive interaction. This database system can extract feature parameters from video, perform automatic indexing, retrieve an appropriate result, and replace a presented object with the retrieval result in real time. Furthermore, we implement the fundamental functions of the proposal database. The retrieval accuracy and computational cost of the system are also described.

Methods of interactive image generation using processed video contents, and its 3D model capture are proposed; we mainly stress the key technique of the system and the implementation of moving 3D object extraction. In order to reflect a user's intention for generating new multimedia contents, we discuss the methods of storage, retrieval, and presentation. This system is an example of the novel creation of multimedia contents by using the technologies of computer vision and virtual reality. The user is able to generate novel multimedia contents without shape modeling by a human. The proposed low-cost extraction and interaction algorithm can track objects at 8 frames/sec with sufficient accuracy.

ActiveCube is a bi-directional user interface that supports a person's creative work through constructing and interacting with 3D virtual objects by using actual physical cubes. With this flexible interface, the user can easily construct various 3D structures in a virtual environment by simply combining the cubes. All of the faces of the cubes are the same and can be connected to any face of any other cube. A computer recognizes the constructed 3D structure in real time, so consistency is always maintained between the real environment and its corresponding representation in a virtual environment. Each cube is equipped with a processor for autonomous simulation and communication functions between cubes. A cube also utilizes a sensor for detecting the operational intention of the user and/or a display/actuator used as an output channel. Users can interact with ActiveCube in various ways by using the sensors, and the response to the interaction is also shown by displays/actuators installed on the cube. Each ActiveCube is equipped with both input and output devices, which makes the interface intuitive and helps to clarify the causal relationship between the input of the user's operational intention and the output of simulation results.

This paper describes an interactive manipulation technique for objects extracted from video images by an efficient algorithm in order to produce multimedia contents. An object contained in a video image must be able to be extracted at a reasonable speed and a moving object able to be tracked with sufficient accuracy. Moreover, real object interactions that meet such criteria must be established using techniques for manipulating objects in virtual worlds. The proposed technique has potential to generate novel multimedia contents without using shape modeling. An interactive digital fishtank is described as one example application of the proposed technique. In this application, the user is able to obtain various video sequences of fishtanks from the original video sequence.

A technique is proposed for object manipulation with a virtual tool using multiple exact interactions. Exact test is introduced that uses real-time collision detection for both hand-and-tool and tool-and-object interactions. Chopsticks are adopted for one of the trials of our technique; although they have a very simple shape, they do have multiple functions. Here, a virtual object is manipulated by the virtual chopsticks, which are used by the motion of a user's hand captured by a hand gesture input device. Exact interaction is applied between the hand and chopsticks based on correct table manners. Experimental results demonstrate the effectiveness of the proposed multiple exact interactions, especially for precise object alignment tasks.

Describes an interactive manipulation technique for objects in video images extracted by an efficient algorithm. An object contained in a video image has to be able to be extracted at a reasonable speed and a moving object is able to be tracked within a sufficient accuracy. Moreover, any interaction method for real objects with such functions has to be established using a technique for manipulating objects in virtual worlds. An interactive digital fishtank is described as one example application of the proposed technique. In this application, the user is able to obtain various video sequences of fishtanks from any video sequence.

We propose a manipulation technique to intuitively control the "bird's eye" overview displav of an entire large-scale virtual environment in a display system that present a user with both overviews (global views) and a life-size virtual environment (local view) simultaneously.It enables efficient navigation even in enormous and complicated environments using both global and local views.The motion of the bird's eye viewpoint interlocks with the relative motion of the user's viewpoint and his/her hand, therefore, the user can control the "bird's eve" viewpoint by intuitive manipulation.Sophisticated display techniques are obtained based on the proposed method by introducing some constraints on the parameters of the "bird's eye" viewpoint.Experimental results show a combination of the bird's eye overview image and the life-size local image is displayed to the user by reflecting his/her intuitive manipulation.1

An MPEG2 video decoder core dedicated to MP@HL (Main Profile at High Level) images is described with the main theme focused on an inverse discrete cosine transformer and a motion compensator. By means of various novel architectures, the inverse discrete cosine transformer achieves a high throughput, and the motion compensator performs different types of picture prediction modes employed by the MPEG2 algorithm. The decoder core, implemented in the total chip area of 22.0 mm/sup 2/ by a 0.6-/spl mu/m triple-metal CMOS technology, processes a macroblock within 3.84 /spl mu/s, and therefore is capable of decoding HDTV (1920/spl times/1152 pels) images in real time.>