Pingguo Huang

QoE assessment of olfactory media in remote ikebana with haptic media

In this paper, we handle a remote ikebana (i.e., flower arrangement) system with olfactory and haptic media. In the system, a teacher or a student can hold a flower, adjust the length of the held flowers stem with a pair of scissors, and impale the flower on a flower pinholder in a 3-D virtual space. We make QoE (Quality of Experience) assessment of olfactory media to investigate the influence of the output timing of olfactory media by changing the size of smell space (defined as a sphere in which we can perceive the smell of flower). In the assessment, each subject is asked to move a rose toward or away from his/her viewpoint, and he/she judges how good the output timing of olfactory media is. We illustrate that there exists the optimum value of the smell space size, and the optimum value depends on the average movement speed and the direction of movement.

Interactivity improvement of group synchronization control in collaborative haptic play with building blocks

This paper proposes a group synchronization control scheme with prediction in collaborative haptic play with building blocks. The scheme adjusts the output timing among multiple terminals and keeps the interactivity high. It outputs position information by predicting a future position later than the last-received position information by a fixed amount of time. It also advances the output time of position information at each local terminal by the same amount of time. By experiment, we subjectively assess the output quality of haptic media so as to demonstrate the effectiveness of the scheme.

Collaborative haptic play with building blocks

This paper introduces collaborative haptic play with building blocks which we have developed. In the play, two users do collaborative work in a 3-D virtual space by using haptic interface devices. By subjective assessment, we investigate the influences of network latency and packet loss in work where two users lift and move the blocks to build a doll-house and in work where two users lift and move the blocks from an area to another area. We deal with three cases of collaborative play in the two types of work. In one case, the two users carry the blocks by holding them together. In another case, the users carry the blocks alternately by holding them separately. In the other case, one of the two users carries each block from a position and hands the block to the other of the two users, who receives it and then carries it to another position. Assessment results show that the operability in the first case is the best among the three cases.

Effect of dynamic control of fragrance output timing in networked virtual environment

In this paper, we propose dynamic control of output timing of fragrance in a networked virtual environment to improve Quality of Experience (QoE). The control changes the output timing of fragrance dynamically according to the movement speed and direction of an object which is a fragrance source. We implement the control in a remote ikebana system using olfactory and haptic media and investigate the effect of the control by QoE assessment. As a result, we demonstrate that Mean Opinion Score (MOS) in the case where the control is used is high and does not largely depend on the average movement speed and movement direction of a flower, which is a fragrance source.

QoE assessment of will transmission using haptics: Influence of network delay

This paper deals with collaborative work in which two users lift and move an object cooperatively to eliminate a target in a 3-D virtual space. In the work, the users transmit their wills about the movement direction of the object to each other by haptics. By experiment, we investigate the influence of network delay on will transmission using haptics. As a result, we demonstrate that it becomes more difficult to transmit the wills accurately as the network delay increases.

Trade-off Relationship Between Operability and Fairness in Networked Balloon Bursting Game Using Haptic Interface Devices

This paper investigates the trade-off relationship between the operability of haptic interface device and the fairness between players by carrying out subjective and objective QoE (Quality of Experience) assessments in a networked balloon bursting game. In the game, two players burst balloons in a 3D virtual space by using haptic interface devices, and they compete for the number of burst balloons. As a result, we confirm that there exists a trade-off relationship between the operability and fairness; that is, if we try to improve the fairness, the operability is degraded when the network delays are different from terminal to terminal; if we try to improve the operability, the fairness is damaged. We also find that the contribution of the fairness is larger than that of the operability to the comprehensive quality (i.e., the weighted sum of the operability and fairness). Assessment results further show that the output timing of terminals should be adjusted to the terminal which has the slowest output timing to maintain the fairness when the difference in network delay between the terminals is large. In this way, the comprehensive quality at each terminal can also be maintained as high as possible.

Simultaneous Output-Timing Control in Networked Games and Virtual Environments.

In this chapter, we make a survey of techniques for simultaneous output-timing control, which adjusts the output timing of media streams among multiple terminals in networked games and virtual environments. When media units (MUs, each of which is the information unit, such as a video frame and a voice packet for media synchronization) are transmitted over non-guaranteed Quality of Service (QoS) networks like the Internet, the receiving times of each MU at the terminals may be different from each other owing to network delays and delay jitters. Therefore, for example, the fairness among players may be damaged in networked games, and collaborative work may not be done efficiently among users in virtual environments. It is important for multiple players/users to play/do networked games/collaborative work while watching the same displayed images simultaneously. To solve the problems, the simultaneous output-timing control, such as media synchronization control and causality control is needed. In this chapter, as the control, we mainly handle the group (or inter-destination) synchronization control, which is a type of media synchronization control, the adaptive Δ-causality control, and the dynamic local lag control. We also discuss the similarities and differences among the three types of control. Generally, the group synchronization control or adaptive Δ-causality control can be employed to keep the fairness and/or the consistency in good conditions among multiple terminals in networked games and virtual environments, and the dynamic local lag control is used for sound synchronization in networked virtual ensembles. However, the interactivity may seriously be deteriorated under such types of control. Therefore, we introduce prediction control to improve the interactivity. As a result of Quality of Experience (QoE) assessment, we demonstrate that the prediction control improves the interactivity and there is the optimum prediction time according to the network delay. Finally, we discuss the future directions of simultaneous output-timing control in networked games and virtual environments.

Media Synchronization in Networked Multisensory Applications with Haptics

In this chapter, we explain the present status of studies for media synchronization in networked multisensory applications with haptics. We also specify the characteristics of haptic media and different features of haptic media from other media such as olfactory, auditory, and visual media. By using such other media together with haptic media, we can get higher realistic sensation when we use the applications for various purposes such as remote education, entertainment, and networked games. When multisensory media streams are transmitted over a network like the Internet, the temporal relationships among the media streams may be disturbed owing to the network delay, delay jitter, and packet loss. Thus, the quality of experience (QoE) may seriously be degraded. To solve this problem, we need to carry out media synchronization control. To achieve a high quality of media synchronization, a number of media synchronization algorithms have been proposed so far. Especially, in networked multisensory applications, we need to take account of human perception of media synchronization errors in the algorithms. This is because the requirements of media synchronization quality depend on types of media. Some algorithms such as Virtual-Time Rendering (VTR) take human perception of the errors into account. For example, VTR tries to accomplish the synchronization by changing the buffering time of each media stream dynamically according to the network delay jitter with several threshold values about the errors. In the algorithms, instead of synchronizing the output timings of media streams exactly, ranges of human perception such as the allowable range, in which users feel that the synchronization error is allowable, the imperceptible range, in which users cannot perceive the error, and the operation range, which is narrower than the imperceptible range and should be kept usually, are taken into account for the sake of high synchronization quality. In this chapter, we explain the algorithms taking account of human perception of the media synchronization errors and enhance other algorithms such as the group (or inter-destination) synchronization control and the adaptive ∆-causality control algorithms for simultaneous output-timing control among multiple terminals by taking account of the perception. It is indispensable to clarify the ranges by QoE assessment in networked multisensory applications. In this chapter, we further make a survey of studies on the assessment. Finally, we discuss the future directions of media synchronization in networked multisensory applications with haptics.

Reliability Specification of Telecommunication Networks Based on the Failure Influence by Using Evolutional Algorithm

For the first step of the reliability design of telecommunication networks, the reliability requirements should be determined. The method to determine the reliability requirements which takes account of the social loss caused by service outage has been established for telephone network in Japan. The feature of above method is to determine the reliability requirement of network element by solving the equation between the loss and reliability of the simple structure of networks, i.e. subscriber areas or transit lines. Therefore, the previous method cannot be applied for the general structure of networks, i.e. the NGN architecture consisted of various control equipment. This paper has investigated the possibility to determine the reliability requirement of network element evolutionally by allocating the traffic demand and the loss caused by failure to the concerned element.

Ikebana competition in networked virtual environment with haptic and olfactory senses

In this paper, we present an ikebana (i.e., Japanese traditional art of flower arrangement) competition system in a networked virtual environment with haptic and olfactory senses. In the system, each user can hold a flower, adjust the length of the held flowers stem with a pair of scissors, and impale the flower on a flower pin-holder in a 3D virtual space over a network. After the server of the system has received arrangements from users, the best arrangements are selected by votes of users and/or ikebana experts at remote locations.