• Journal of KIISE:Databases
• /
• v.30 no.5
• /
• pp.521-531
• /
• 2003

Multi-level geographic data can be mainpulated by a window query such as a zoom operation. In order to handle multi-level geographic data efficiently, a spatial indexing method supporting a window query is needed. However, the conventional spatial indexing methods are not efficient to access multi-level geographic data quickly. To solve it, other a few spatial indexing methods for multi-level geographic data are known. However these methods do not support all types of multi-level geographic data. This paper presents a new efficient spatial indexing method, the MLR-tree for window query of multi-level geographic data. The MLR-tree offers both high search performance and no data redundancy. Experiments show them. Moreover, the MLR-tree supports all types of multi-level geographic data.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.12
• /
• pp.2926-2932
• /
• 2014

Smart Phone market consists of several platforms such as Windows Phone, Apple iOS and Android of Google. Each platform uses different coding style respectively. Platform-dependent application results in high cost and low code reusability during development of application. It also provides heterogeneous display forms to users. In this paper, we propose a platform-independent generic interface model that could be operated in both the various smart phones and PC. Because the proposed model provides the same UI on multiple platforms, users can operate applications without awkwardness. The model includes a module which copes with the changes of the resolutions in various platforms and a module which switches scenes of each application for performance improvement. Moreover, a module which connects DB is also proposed in order to overcome the difference of way to store data in each platform. The implementation results show that the difference of display and operating manner in any hetero-platform is eliminated.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.1
• /
• pp.81-86
• /
• 2016

In this paper, we present multi-channel authentication based security card design. Since this security card is written on the transparent paper, security information is extracted by overlaying the card with smartphone screen. This method removes the limitations of physical layout in previous security card and improves the security level. Furthermore, our security card is secure when our card is exposed to malicious users.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2023.01a
• /
• pp.479-480
• /
• 2023

증강현실(Augmented Reality, AR)은 물리적 현실세계에 가상의 세계를 중첩하여 부가적인 정보나 서비스를 제공하는 것으로 대부분 스마트폰과 같이 카메라를 장착한 기기를 이용하게 된다. 스마트폰의 카메라가 마커를 인식할 경우 가상의 오브젝트가 화면에 중첩하여 보이게 되는 것이다. 카메라가 인식하는 마커를 하나 이상 사용할 수 있다. 다중 마커를 사용하는 경우 마커를 인식할 때 중첩되는 가상의 오브젝트를 동일한 것으로 사용할 수도 있고 각 마커별로 다른 가상 오브젝트를 사용할 수도 있다. 본 논문에서는 전시되어 있는 작품을 마커로 등록하여 각 이미지별로 작품의 정보가 중첩되어 나타나도록 유니티의 AR 파운데이션 프레임워크를 이용하여 구현한다. 여러 작품이 전시되므로 이를 다중 마커로 사용하고 각 작품별 정보가 각기 다르게 출력되도록 구현한다.

• Proceedings of the KIEE Conference
• /
• 2008.04a
• /
• pp.86-88
• /
• 2008

지상파 방송(DMB: Digital Multimedia Broadcasting)은 음성, 영상, 데이터와 같은 다양한 멀티미디어 신호를 디지털 방식으로 변조하여 이동 중에 방송을 청취 할 수 있는 차세대 디지털방송 서비스이다. 하지만 한정된 대역폭으로 인한 비디오 전송율의 한계에 따라 최대 CIF(Common Interleaved Frame)급 화면해상도까지 서비스가 가능하다. 그러나 지상파 DMB 전송 고도화망에서는 계층 변조(Hierarchical Modulation)전송 기법을 통하여 추가의 전송대역폭을 확보할 수 있다. 또한 스케일러블 비디오 코딩(Scalable Video Coding)부호화 방식을 이용하여 고전송효율/고품질의 이동 멀티미디어 방송서비스를 제공할 수 있는 고품질 AT(Advanced Terrestrial)-DMB 시스템이 가능하다. 이러한 고품질 AT-DMB의 개발에 있어서 여러 방식들이 제시됨에 따라 시뮬레이터를 통한 다중화 시스템의 분석이 필요하다. 본 논문에서는 고품질 AT-DMB가 가능한 스케일러블 비디오 방식을 JM8.8을 사용하여 구현하였으며, 다중화 시스템의 실험을 하였다. 또한 시뮬레이터를 통하여 확보된 계층 간의 화질 차이와 엔지니어를 위해 비트스트림의 분석화면 및 PSNR을 제공 하였다.

• Journal of Broadcast Engineering
• /
• v.20 no.6
• /
• pp.928-937
• /
• 2015

A portable head up display (HUD) using the optical combiner lens with a 0.47inch LCD panel for a portable multi-windows virtual display is proposed. The proposed system consists of several micro panels, optical devices, and RGB 3in1 light-emitting diodes (LED) for making the full color display, and video and audio format for the high definition multimedia interface (HDMI) for the connecting between HUD and mobile phone. The multi-windows HUD is designed as an alternative to conventional built-in type HUD targeting the mass volume aftermarket at an affordable price.

• Journal of Broadcast Engineering
• /
• v.26 no.1
• /
• pp.3-13
• /
• 2021

We propose a moire artifacts removal algorithm for screen-shot images using multiple domain learning. First, we estimate clean preliminary images by exploiting complementary information of the moire artifacts in pixel value and frequency domains. Next, we estimate a clean edge map of the input moire image by developing a clean edge predictor. Then, we refine the pixel and frequency domain outputs to further improve the quality of the results using the estimated edge map as the guide information. Finally, the proposed algorithm obtains the final result by merging the two refined results. Experimental results on a public dataset demonstrate that the proposed algorithm outperforms conventional algorithms in quantitative and qualitative comparison.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.623-625
• /
• 2013

This signal can be distributed using a single USB cable, computer, video, audio, USB, LAN, one USB multi-signal transmission system was designed and implemented. USB multi-signal transmission was implemented in order to convert a single DVI, audio, and multiple USB, LAN, USB signal converter modules. This USB DVI port supports up to 1920 * 1090 resolution. USB multi-signal transmission system by sending multiple signals into a single cable installation costs of the various cable and using the replication feature of the screen, will provide schools and institutes, etc., providing the convenience of the river, and the scalability of computer peripheral ports.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.6
• /
• pp.67-74
• /
• 2006

In this paper, a tiled display system is developed to get a high-resolution image in visualization of large-scale structural analysis data with low-resolution display devices and low-cost cluster computer system. Concerning the hardware system, some of the crucial points are investigated, and a new beam-projector positioner is designed and manufactured to resolve the keystone phenomena which result in distorted image. In the development of tiled display software, Qt and OpenGL are utilized for GUI and rendering, respectively. To obtain the entire tiled image, LAM-MPI is utilized to synchronize the several sub-images produced from each cluster computer node.

• Journal of KIISE
• /
• v.43 no.4
• /
• pp.399-403
• /
• 2016

Deferred Shading is a shading technique that postprocesses pixels in the screen space, following geometry-only rendering passes with depth buffering. Unlike typical shadow mapping techniques, this technique allows us to render shadows from multiple light sources without changing the structure of the rendering pipelines. This paper presents a deferred shadow mapping technique and its extension to soft shadows using mipmapping. Our technique first generates visibility maps from light sources, and blurs the visibility maps for deferred shading. This strategy leads to efficient soft-edged shadows, but does not incorporate depth variation, producing light bleeding to some extent. In order to suppress the light-bleeding artifacts, we also propose a depth-adaptive mipmap sampling technique in the screen space.