Catálogo de publicaciones - libros

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.

In a NVE like massively multi-player online game, messages of participants should be synchronized. A solution for the synchronization problem is to wait for a certain amount of time until the server processes the messages, however determining a suitable waiting period is not easy because of the trade-off between the fairness and the responsiveness. In this paper, we develop methods to determine the waiting period using the probability of interaction among participants and ranks of delays of participants. Our methods take advantages of the property that, in a game with geographical map, each participant usually interacts with the participants around him. We built a NVE for simulation and compare proposed methods with popular method that uses the maximum expected delay as the waiting period. The experiment shows that the proposed method produces better result with lower average unfair ratio while keeping the same responsiveness, resulting in better synchronization mechanism.

In recent years, thousands or even hundreds of thousands players interact with each other in the MMOG (Massively Multi-player Online Game). Therefore MMOG servers have the problem with scalability. To overcome this problem, we propose a new method for MMOG distributed server, denoted as method. method constructed with and . The includes important aggregated informationof game objects such as virtual space, users, monster, etc. And the includes real data of game objects. This paper makes the following contributions. First, it captures these problems of high storage cost and slow processing time for previous methods. Second, it proposes parallel processing strategies that aim to reduce process time. Third, it proposes an efficient partitioning algorithm for distributed servers. Our experiment results show that our method is better scalable than existing methods.

CSCL systems are valuable supports for distance and face to face learners as well. With the aim of offering the accurate information to learners, the graphical interface of the environment has to be designed in a manner that it offers the right elements to participate and understand the collaboration in the environment. The aim of this paper is to offer the design of a discovery learning environment called Co-Lab and how the collaborative graphical interface has been built on it.

Recently, research on augmented games as a new game genre has attracted a lot of attention. An augmented game overlaps virtual objects in an augmented reality(AR) environment, allowing users to interact with the AR environment through manipulating real and virtual objects. However, it is difficult to release existing augmented games to ordinary gamers, as the games generally use very expensive and inconvenient ‘backpack’ systems. Accordingly, this paper introduces an augmented game, called based on traditional well-known , executed on mobile devices to make game players experience the game without any economic burdens. uses real space, such as a room, as game environment, and covers the real widespace with a small screen of mobile devices by actually moving the mobile devices. In an initial stage, the specific objects are selected by game players, and are automatically recognized by scale-invariant features in playing a game. Then, virtual insect-like aliens randomly appear in several specific regions displayed on the mobile screen, and game players attack it by moving the mobile devices towards specific regions with virtual aliens and clicking a button of mobile devices. As a result, we expect that provides an exciting experience without any economic burdens for players based on the game paradigm, where the user interacts with both the physical world captured by a mobile camera and the virtual aliens automatically generated by a mobile device.

A programmable graphics pipeline including the shader in the embedded systems increases flexibility and enables customizations of vertex and fragment processing, and it also provides the programmer with various special effects essential in development of realistic 3D mobile games whereas the traditional fixed-function pipeline does not. In this paper, we design a unified shader integrating vertex shader and fragment shader, define a memory structure for the unified shader, and present an operating process to construct the memory structure and execute compiled shader program by passing it to the unified shader using the OpenGL ES 2.0 APIs. We are satisfied with the result from implementing the unified shader and its OpenGL ES 2.0 APIs. It can be used as a development platform for 3D mobile games.

With the development of simulation scalability, federates of various abilities are required to cooperate in a virtual environment. Restricted to HLA(High Level Architecture) standard, all the subscribing federates have to process the same traffic from an virtual object. As a result, existing RTI(Run-Time Infrastructure) software cannot conduct flow control on low-bandwidth federates. This paper suggests to reduce the object updating frequency and to restrict the update interval based on LoI(Layer of Interest) according to the host bandwidth. A bandwidth adaptive flow control model was built on the basis of LoI. This model depicts the way to conduct flow control with fidelity guarantee. Flow control algorithms are proposed to drop update packets according to the object LoI and packet LoI. Experiments illustrated that the flow control model can cut down the federate bandwidth requirements.

In recent years, many researchers are attracted to computer games research. Capable gamers can easily get bored, while beginners tend to give up after trying several times because the game does not correspond to their level of interest. Therefore, this paper proposes that the user’s play pattern to be modeled on the basis of probability and level designer will dynamically generates the gaming level accordingly. We analyze user’s play pattern and design pattern based on GMM (probability model) and dynamically generate the level with online learning technique adapting the reinforcement technique. The play pattern is modeled using GMM and in order to create game level dynamically, the method of updating the weight of enemy creation using online script is proposed. Finally, we apply our proposed method to a 2D shooting game and introduce user’s play pattern leading to design pattern in the game.

The paper reports how to assist university learners to study TRIZ, which is a series of useful tools, methods and strategies for solving inventive problems systematically, by means of computer games. The aim of this project is to help players to practice and understand their basic TRIZ knowledge and technique effectively and efficiently by playing online mini games. The paper goes through several major tools of TRIZ, Inventive Principles, Trends of Evolution, Contradiction and Engineering Parameters, and finally evaluates their educational and entertainment values to the player in terms of level design, feedback and interaction.

This paper describes an Augmented Reality based approach for use in museums and science centers for explanation, which is designed to improve visitors understanding. The distributed Augmented Reality system uses hybrid tracking technologies to detect the position and orientation of the museum visitor and measures a specific exhibit state with data acquisition sensors. Furthermore, we enhanced our system with an Augmented video streaming technology for remote participation and we developed the Mixed Reality Interface Markup Language (MRIML) to support high-level, platform independent scenario specification.