Yonghee You

An Experimental Study on the Performance of Haptic Data Transmission in Networked Haptic Collaboration

In this paper, we present preliminary results of our ongoing networked virtual reality project by discussing the implementation and performance of an experimental haptic collaboration system; a networked haptic basketball game. In this game, online players feel like handling a real basketball since they are able to feel the sense of touch by using haptic interfaces. One of challenging issues in this implementation is haptic data transmission over the Internet to allow online multi-user play. Since haptic information is extremely sensitive to delay, jitter, and loss, the provision of timely transmission is critical. We carry out some experiments to compare the performance of the haptic data transmission under various delays, jitters, and losses of packets for two models; one is the position transfer model and the other is the force transfer model. We observe that loss of packets may reduce the force feedback in the Position Transfer Model and jitters are more sensitive than delays for both models.

Sound-Specific Vibration Interface using Digital Signal Processing

The adoption of vibration interfaces in the games and the virtual reality is increasing since they improve the user experience. The principle of existing vibrating devices is to vibrate when detecting the presence of particular frequency bands. However such frequency-based scheme, according to our survey, cannot meet the user expectation; they vibrate too often and even at unwanted moments, having users feel haptically-numb soon and being annoyed. We develop a sound-specific vibration interface. It is wrist-wearable and vibrates at only designated target sounds. It uses a real time sound matching algorithm. Using the FFT, the algorithm compares the similarity of the frequency distribution between the input sound and the target sounds. In the performance test applying the interface to a commercial game,the matching success rate was 80% while the computation delay was 415 ms. Such results confirm the applicability of the proposed interface to the game play.

An Integrated Haptic Data Transmission in Haptic Collaborative Virtual Environments

Haptic collaboration virtual environment (HCVE) is an enhanced virtual reality space with haptic interface support. HCVE users are connected together over the network and are able to work together by using sense of touch, i.e. haptics as well as audio and visual interfaces. In HCVE, the communication of haptic data is challenging because of time-varying network conditions and extremely high data rate. To mitigate such difficulties, we propose a linear prediction algorithm and a buffering scheme which is an integrated scheme for haptic data transmission. The prediction algorithm is to minimize the negative effects from network delay, loss and jitter, while the buffering scheme is to easily synchronize haptic interaction. For the evaluation of our proposed schemes, we build an experimental test bed for HCVE. As the result, we observe that our schemes are effective in improving the quality of haptic experiences. The quantitative measurement results are presented.

Sound-Specific Vibration Interface: Its Performance of Tactile Effects and Applications

The tactile effects of a sound-specific vibration interface is presented in this paper. The sound-specific vibration interface generates a vibration according to a sound stream using 16 oscillators arranged in 4 times 4 array. By setting time frame, we were able to generate various patterns of vibrations. So, the main purpose of this paper is to analyze the effectiveness the sound- specific vibration interface. We first analyze the immersiveness of the vibration depending on the tone of sound. Second, different parts of body were evaluated to find the most suitable part of body for our sound-specific vibration interface. Next, we also assess the various patterns of vibration using four patterns for a gun-shot. In addition, we also compare the results of the vibration device with those of two other vibration interfaces: a vibrating mouse and a vibrating head-set. In the experiment, participants listened to music and played a shooting game, wearing our sound-specific vibration interface. The experiments on different patterns of vibrations lead us to conclude that a certain vibration pattern is more effective than others and our vibrations interface is more effective than other vibrating devices, especially it works best when being attached to shoulders.

Mobile Mapping Service Using Scalable Vector Graphics on the Human Geographic

Mobile and wireless technologies have evolved rapidly in recent years, especially the development of hardware devices, such as PDA and Smartphone. Telecommunication service providers, manufacturers and other developers have launched different kinds of services and applications in these mobile devices. Mobile Geographic Information and Location Based Service appear recently to help people to establish spatial relationship with the surroundings. Map, which is a useful tool to assist a person to define a position in a particular area, is usually included in these systems. However, there is no standard format of graphic presentation for map in mobile devices. In this paper, the effective method was suggested for the transmission of the geographic information acquired by camera attached to a PDA such as position data, attitude data, and image data in the wireless internet environment in real-time.

Experiments on the Tactile Effects of a Sound-Specific Vibration Interface

In this paper, we present the tactile effects of a sound-specific vibration interface. The sound-specific vibration interface generates vibration patterns with varying frequencies of sound by activating 16 oscillators in a 4times4 array within a set time frame. The main purpose of this paper is to analyze the effectiveness of this vibration interface depending on the position of the body to which it is attached and the types of vibration patterns it produces. In addition, we also compare the results of the vibration device with those of two other vibration interfaces: a vibrating mouse and a vibrating head-set. In the survey, participants played a first person shooting game, wearing one of the three mentioned vibration interfaces The results of the surveys show that the sound specific vibration interface is more effective than the other vibration devices and most effective when attached to the shoulder. The survey on different patterns of vibrations also indicate that a certain vibration pattern is more effective than others.

Data transmission for haptic collaboration in virtual environments

In this paper, we mainly present the analysis on the haptic data transmission over real network conditions in a networked haptic collaboration environment. Since haptic data are produced at the rate of 1khz, the transmission of haptic data is extremely sensitive to packet loss, and time variation. We took some experiments for transferring haptic data under various network conditions such as packet loss, time delay and jitter. The experiments lead us to find that the unstable network conditions can cause the problems of inconsistent view and irregular force feedback in networked haptic applications. In order to overcome those problems, we tried to use a simple linear prediction algorithm for the haptic data transmission and the simple prediction algorithm shows better performance. In conclusion, a simple prediction algorithm can be a reasonable solution for the haptic data compensation in networked haptic applications.

MuseSpace: a touchable 3D museum with maximum usage of haptics

We present a networked haptic virtual museum; MuseSpace. The main objective of our MuseSpace is to build a virtual musical instrument museum for both education and entertainment. In our MuseSpace, various touchable musical instruments and artifacts are displayed and people can touch them freely by using haptic devices, while in real museums, people are usually not allowed to touch them by keeping those instruments and artifacts in glass showcases in order to prevent possible damages from touches. In addition, we enhance the accessibility, e.g. navigation control, instrument handling, with the help of haptic devices. One of the significant advantages of MuseSpace is that it provides visitors with the chances to experience instruments more interactively by supporting diverse interface media: audio, video, and touching.