Wookho Son

Three-Dimensional Imaging for Creating Real-World-Like Environments

Three-dimensional imaging is still not in the full commercial stage, but its application is widening due to its capability of creating real-world-like environments. This capability is especially important in realizing reality communication and telepresence operations in medical and unreachable places. For these applications, technologies for interacting with objects in the 3-D image should also be developed. The widespread use of 3-D images is expected in near future, but before that, problems of minimizing physical stresses, especially eye fatigue, should be solved for 3-D imaging. Currently, expected solutions to the problems are electroholography and super multiview methods. These two methods work at different principles, but they both can provide the continuous parallax as in the real-world scenes/objects. Electroholography can also provide focusable depth information to the viewers, though its viewing zone angle is limited. For the super multiview, it is not apparent that it can provide the focusable depth information, but it can provide more comfortable viewing condition than the holography because of its wider viewing zone angle.

A new means of HCI: EMG-MOUSE

EMGs are a natural means of HCI because the electrical activity induced by the humans arm muscle movements can be interpreted to used as computers control commands. In this paper, we present an on-line EMG-MOUSE system that controls movements of a cursor, which are interpretations of 6 pre-defined wrist motions: up, down, left, right, click, and rest. To emphasize a wearability, we designed the hardware in a way that electrodes are located on a circular armband, which wraps around the forearm. The prototype hardware device has as integrated parts both the EMG electrodes and an amplifier for magnifying EMG signals, without using adhesive to attach the electrodes on the forearm. A fuzzy min-max neural network (FMMNN) was used as a classifier. Also, stochastic values such as integral absolute value were used as features for an appropriate classification of the intended wrist motions. From our experiments, we could observe that six distinctive wrist motions can be classified well, once the patterns are learned

Efficient mobile museum guidance system using augmented reality

We propose a mobile augmented reality (AR) system for helpful and efficient museum guidance. The system can provide not only useful information of exhibitions such as their inside view, origination, and how-to-use, but also a variety of interactions with the exhibitions. The system prototype is implemented on ultra mobile personal computer (UMPC) which is equipped with a camera, an ultrasound receiver, and a gyro sensor. The system function consists of two parts: tracking part, and event handling and visualization part. The tracking part consists of two parts again: global pose tracking part using ultrasound sensors and a gyro sensor, and local pose tracking part using a vision sensor which computes effectively the camera pose under less-controlled environments by combining edge information with feature point information of the camera images. The usefulness of the proposed system and user satisfaction are evaluated through the experimental results in various scenarios.

Virtual Reality based Paint Spray Training System

We present a virtual reality (VR) system that simulates the situation of ship block spray painting. The system was developed under demands from ship building industry for training purpose. We designed an immersive stereo display platform, a realistic spray painting rendering technique and intuitive user interface to match with the real working environment. The system is currently under user-test in the ship building company with receiving positive responses.

A Practical Biosignal-Based Human Interface Applicable to the Assistive Systems for People with Motor Impairment

An alternative human interface enabling the handicapped with severe motor disabilities to control an assistive system is presented. Since this interface relies on the biosignals originating from the contraction of muscles on the face during particular movements, even individuals with a paralyzed limb can use it with ease. For real-world application, a dedicated hardware module employing a general-purpose DSP was implemented and its validity tested on an electrically powered wheelchair. Furthermore, an additional attempt to reduce error rates to a minimum for stable operation was also made based on the entropy information inherent in the signals during the classification phase. In the experiments in which 11 subjects participated, it was found most of them could control the target system at their own will, and thus the proposed interface could be considered a potential alternative for the interaction of the severely handicapped with electronic systems.

Basic image cell in contact-type multiview three-dimensional imaging systems

Abstract. The viewing zone of a contact-type multiview three-dimensional imaging system are divided into nine viewing regions by assuming that at least n−2 pixel cells can be viewed at each of the regions, where n is the total number of pixel cells in horizontal direction of a display panel. Each of these regions consists of m2 subregions, where m is the number of pixels in the horizontal of a pixel cell. The image viewed at each of the subregions reveals a disparity of 1 pixel distance with that viewed at its adjacent subregion. Hence, each subregion is defined as a basic image cell that can provide the disparity of a pixel distance with its immediate neighbors. The width of the cell is independent of the focal length of the viewing zone forming optics but highly sensitive to the pixel size. It can be smaller than viewers’ pupil sizes by decreasing the pixel size.

Detecting and monitoring game bots based on large-scale user-behavior log data analysis in multiplayer online games

Online games with a variety of genres and game style have become popular. While the market for online games is growing, unauthorized program software is used and operated by some users. They damaged fair players and furthermore, bot program users have inflicted a huge loss to game service companies. Bot programs show various game play action styles and there are many users not only in Korea but also other countries, so it is not easy to trace. Also, as users of online game and smart device game which is focused recently are increasing, log data quantity are explosively increased and demands of analysis on not only bot information, but also statistical information which is necessary for game operation plan from log information. This paper examines bot program of online game, detection method and tendency of log data management technology for it. This paper introduces our method to detect game bots and manage game log data.

MIRAGE: A Touch Screen based Mixed Reality Interface for Space Planning Applications

Space planning is one of the popular applications of VR technology including interior design, architecture design, and factory layout. In order to provide easier and efficient methods to accommodate physical objects into virtual space under plan, we suggest applying mixed reality (MR) interface. Our MR system consists of a video see-through display with a touch screen interface, mounted on a mobile platform, and we use screen space 3D manipulations to arrange virtual objects within the MR scene. Investigating the interface with our prototype implementation, we are convinced that our system will help users to design spaces in more easy and effective way.

Design evaluation using virtual reality based prototypes: towards realistic visualization and operations

In this paper, we introduce a method for design evaluation of mobile devices using virtual reality based prototypes. For this, we present technologies for a classification of design parameters and for visualizing mobile devices with high quality 3D data. Also, we describe an implementation method for natural simulation and interaction of product functions.

A holographic display based on spatial multiplexing

A DMD chip is capable of displaying holographic images with a gray level and of reconstructing its image only in the space defined by the diffraction pattern induced from its pixel arrangement structure. 2 X 5 DMD chips are combined on a board to generate a spatially multiplexed reconstructed image of 10cmX2cm. Each DMD chip generates an image piece with the size of 2cm (Horizontal) X 1cm (vertical). The reconstructed image reveals the features of original object image including the gray level but noises from several sources are also laden with it.