• Journal of the Korea Society of Computer and Information
• /
• v.11 no.2 s.40
• /
• pp.187-199
• /
• 2006

This paper proposes the design of user centric pavilion information guide system based on mobile device such as PDA. which is composed of system interface factors as user wants. The suggested information guide system is convenient for user carrying because it is based on PDA mobile device and the used liquid browser system makes all data information displayed on a small screen in contrast with the other browser system. Indeed, factors of system interface can be re-composed by user interaction. And this system can effectively provide the detail information about the exhibited objects as various media data such as text, image, voice, music, video etc. The proposed system is made up of media database server. mobile system control server and mobile system interface which accepts user interaction and displays the information. Each system is networked based on TCP/IP and uses XML (extensible Markup Language) and JAVA 2 micro edition to be able to update data. This feature enhances a wide use to be able to load this system on the any mobile device.

• Journal of the Korea Computer Graphics Society
• /
• v.25 no.3
• /
• pp.43-54
• /
• 2019

In this paper, we review the applicability of fog screen to implement 'Spatial Augmented Reality' which displays the image on the whole space of real space or in real space by separating display equipment and user, in contrast to the traditional Augmented Reality. Through three exhibitions and one performance, we confirmed t hat the fog screen, which can be passed through, is a suitable material for implementing the Spatial Augment ed Reality. We found that the hologram production was easier than before because of fog screen. Through the questionnaire survey conducted on performers along with the exhibition, we found that only about half of people know what a fog screen is, and about 10% of the total respondents saw the fog screen. In order to investigate the effect of fog screen on the surrounding space, we conducted an experiment to observe the change of humidity according to the time and distance in the Children's Culture Center of the Asian Culture Center. We found that the humidity within a radius of 5m around the fog screen could increase by 2~3%($6,400m^3$ standard). Thus we provided some safety requirement with fog screen when works made of materials vulnerable to moisture such as paint, paper, and wood are exhibited at the same time with fog screen in the exhibition hall.

• Journal of Korean Ophthalmic Optics Society
• /
• v.6 no.2
• /
• pp.71-75
• /
• 2001

In this paper, a three-dimensional measuring system of thermoluminescence(TL) spectra based on temperature, wavelength and luminescence intensity was introduced. The system was composed of a spectrometer, temperature control unit for thermal stimulation, photon detector and personal computer for control the entire system. Temperature control was achieved by using feedback to ensure a linear-rise in the sample temperature. Digital multimeter(KEITHLEY 195A) measures the electromotive force of Copper-Constantan thermocouple and then transmits the data to the computer through GPIB card. The computer converts this signal to temperature using electromotive force-temperature table in program, and then control the power supply through the D/A converter. The spectrometer(SPEX 1681) is controlled by CD-2A, which is controlled by the computer through RS-232 communication port. For measuring the luminescence intensity during the heating run, the electrometer(KEITHLEY 617) measures the anode current of photomultiplier tube(HAMAMATSU R928) and transmits the data to computer through the A/D converter. And, we measured and analyzed thermoluminescence of $CaSO_4$ : Dy, P using the system. The measuring range of thermoluminescence spectra was 300K-575K and 300~800 nm, $CaSO_4$ : Dy. P was fabricated by the Yamashita's method in Korea Atomic Energy Research Institute(KAERI) for radiation dosimeter. Thermoluminesce spectra of the $CaSO_4$ : Dy, P consist of two main peak at temperature of $205^{\circ}C$, wavelength 476 nm and 572 nm and with minor ones at 658 nm and 749 nm.

• Journal of Broadcast Engineering
• /
• v.20 no.6
• /
• pp.901-911
• /
• 2015

Many studies tried to develop a 3D display based stereo test as a substitute for the conventional stereo test. Although many 3D monitor based stereo tests have various advantages over the conventional stereo tests with printed stimuli, they have a crucial limitation in manipulating disparity. The least value for disparity manipulation is one pixel, which is too big to screen the normal stereo acuity in pc environment with a short viewing distance. In this explorative study, a Gabor image was employed as a test stimulus, because its position can be manipulated by changing its phase information, which allows sub-pixel manipulation for disparity. Instead of employing the methods of the conventional stereo tests where measurement was made only once for each of a wide range of disparity values, 10 replications were administrated for each of 6 disparity levels. The results from the test using Gabor images were compared with those using random dot stimulus because the latter stimulus was exactly the same as that of the conventional stereo test. The correlation coefficient between two tests was found to be moderate. After one month later, the whole test was repeated in the same settings. The correlation coefficient between test and retest results from Gabor images was found to be as high as that from a random dot stimulus, implying high test-retest reliability. These results suggest that a Gabor stimulus could be used as a test stimulus for the valid and reliable stereo test, even in the limited condition, such as 3D environment with a short viewing distance and a condition for evaluating the stereo acuity very precisely.

• Journal of the Korea Computer Graphics Society
• /
• v.17 no.1
• /
• pp.39-44
• /
• 2011

In this paper, we introduce a novel method to reduce image to a small size, such that the quality of the image is improved when it is up-scaled. Recent hardwares including cameras and display devices allow us to capture and display high-resolution images. However, it is not always realistic to store and transmit those high-resolution images due to limitation of storage and network bandwidth. Therefore, high-resolution images are often down-scaled to be stored and transmitted, and then up-scaled back for display. To improve final image quality in this scenario, we first formulate selected up-scale methods as linear transformations. The optimal reduction methods are obtained as its inverse transformation. Based on this basic idea, we develop down-scale kernel that is optimized for each up-scale method. In our experiment, the proposed method could improve the quality of the up-scaled image noticeable.

• Journal of the Korea Computer Graphics Society
• /
• v.17 no.4
• /
• pp.31-40
• /
• 2011

Projector-based visual systems are widely used for VR and experience display applications. But the illumination irregularity on the screen surface due to the screen material and its light reflection properties sometimes deteriorates the user experience. This phenomenon is particularly troublesome when the participants of the head tracking VR system such as CAVE or the motion generation experience system continually move around the system. One of reason to illumination irregularity is projector-screen specular reflection component to participant's eye's position and it's analysis needs high computation complexity. Similar to calculate specular lighting term using GPU's programmable shader, Our research adjusts every pixel's brightness in runtime with given 3D screen space model to reduce illumination irregularity. For doing that, Angle-based brightness compensate function are considered for specific screen installation and modified it for GPU-friendly compute and access. Two aspects are implemented, One is function access transformation from angular form to product and the other is piecewise linear interpolate approximation.

• Proceedings of the Korean Society of Computational and Applied Mathematics Conference
• /
• 2003.09a
• /
• pp.11-11
• /
• 2003

오늘날 단일 슈퍼컴퓨터로는 처리가 불가능한 거대한 문제들의 해법이 시도되고 있는데, 이들은 지리적으로 분산된 슈퍼컴퓨터, 데이터베이스, 과학장비 및 디스플레이 장치 등을 초고속 통신망으로 연결한 GRID 환경에서 효과적으로 실행시킬 수 있다. GRID는 1990년대 중반 과학 및 공학용 분산 컴퓨팅의 연구 과정에서 등장한 것으로, 점차 응용분야가 넓어지고 있다. 그러나 GRID 같은 분산 환경은 기존의 단일 병렬 시스템과는 많은 점에서 다르며 이전의 기술들을 그대로 적용하기에는 무리가 있다. 기존 병렬 시스템에서는 주로 동기 알고리즘(synchronous algorithm)이 사용되는데, 직렬 연산과 같은 결과를 얻기 위해 동기화(synchronization)가 필요하며, 부하 균형이 필수적이다. 그러나 부하 균형은 이질 클러스터(heterogeneous cluster)처럼 프로세서들의 성능이 서로 다르거나, 지리적으로 분산된 계산자원을 사용하는 GRID 환경에서는 이기종의 문제뿐 아니라 네트워크를 통한 메시지의 전송 지연 등으로 유휴시간이 길어질 수밖에 없다. 이처럼 동기화의 필요성에 의한 연산의 지연을 해결하는 하나의 방안으로 비동기 반복법(asynchronous iteration)이 나왔으며, 지금도 활발히 연구되고 있다. 이는 알고리즘의 동기점을 가능한 한 제거함으로써 빠른 프로세서의 유휴 시간을 줄이는 것이 목적이다. 즉 비동기 알고리즘에서는, 각 프로세서는 다른 프로세서로부터 갱신된 데이터가 올 때까지 기다리지 않고 계속 다음 작업을 수행해 나간다. 따라서 동시에 갱신된 데이터를 교환한 후 다음 단계로 진행하는 동기 알고리즘에 비해, 미처 갱신되지 않은 데이터를 사용하는 경우가 많으므로 전체적으로는 연산량 대비의 수렴 속도는 느릴 수 있다 그러나 각 프로세서는 거의 유휴 시간이 없이 연산을 수행하므로 wall clock time은 동기 알고리즘보다 적게 걸리며, 때로는 50%까지 빠른 결과도 보고되고 있다 그러나 현재까지의 연구는 모두 어떤 수렴조건을 만족하는 선형 시스템의 해법에 국한되어 있으며 비교적 구현하기 쉬운 공유 메모리 시스템에서의 연구만 보고되어 있다. 본 연구에서는 행렬의 주요 고유쌍을 구하는 데 있어 비동기 반복법의 적용 가능성을 타진하기 위해 우선 이론적으로 단순한 멱승법을 사용하여 실험하였고 그 결과 순수한 비동기 반복법은 수렴하기 어렵다는 결론을 얻었다 그리하여 동기 알고리즘에 비동기적 요소를 추가한 혼합 병렬 알고리즘을 제안하고, MPI(Message Passing Interface)를 사용하여 수원대학교의 Hydra cluster에서 구현하였다. 그 결과 특정 노드의 성능이 다른 것에 비해 현저하게 떨어질 때 전체적인 알고리즘의 수렴 속도가 떨어지는 것을 상당히 완화할 수 있음이 밝혀졌다.

• Journal of Korea Game Society
• /
• v.5 no.1
• /
• pp.11-18
• /
• 2005

Recently, as one method of the game manipulation, physical interactive game is increasing, which controls the program by direct human movement. Tangible interface for physical interactive game implementation can control virtual model directly through real world object. A digital desk, one of the tangible interface, offers the interface that human can manipulate virtual object directly, by making projection screen on real world desk as computer display device. In this paper, we implement "Battle Region" game in the form of tangible interface, which can offer game users an efficient and amusing experiences by the use of physical interactive game. Traditional game cannot pursuit the diversity of game background contents but our game can do it through Map image projection. From this, game provider can supply the diversity of choice and users ran set up the difficulty of game. Therefore, our implemented game can offer users an efficient and amusing experiences by making game user's challenge and satisfaction maximum.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.6
• /
• pp.207-212
• /
• 2007

Recently, requriements that people want to receive various information related with fashion are increasing. A lot of internet shopping malls and corporations provide information about fashion. However, those systems do not give enough information about fashion. To solve these problems, the paper provides the recommend technique for providing complex fashion information on mobile devices. The providing system implements fasion ontology by using XML. The XML ontology has dewey number as an attribute. The recommend technique uses this number and find LCA(Lowest Common Ancestor) on the fashion ontology. Then those child nodes under the LCA are recommended as related information. The results are displayed on the mobile browser. The system provides function for taking a picture or movie of fashion contents. Those movies and pictures are UCC(User Created Content)s. The system is a novel system that can recommend complex fasion information on mobile devices.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.6 no.6
• /
• pp.831-838
• /
• 2011

Computer vision research area, a division of computer graphics application area that creates realistic visualization in computer, conducts vigorously researches on developing realistic 3D model or virtual environment. As the popularization and development of 3D display makes common users easy to experience a solid 3D virtual reality, the demand for virtual reality contents are increasing. This paper proposes 3D panorama system using depth point location-based depth map generation method. 3D panorama using depth map gives an effect that makes users feel staying at real place and looking around nearby circumstances. Also, 3D panorama gives free sight point for both nearby object and remote one and provides solid 3D video.