• The Journal of the Korea institute of electronic communication sciences
• /
• v.9 no.8
• /
• pp.861-866
• /
• 2014

This study evaluates the modeling accuracy of the existing three phase shift models on which the time domain oscillator phase noise theories are based. For the evaluation, this study investigates how accurately the three models can model the phase shift impulse train response of a simple planar oscillator. Evaluation result reveals that Kaertner model most accurately reflects the oscillator's phase shift impulse train responses for five different impulse train inputs, whereas PP model exhibited the worst performance in modeling the phase shift impulse train responses.

• Journal of the Korean Geophysical Society
• /
• v.9 no.4
• /
• pp.371-376
• /
• 2006

Digital high resolution cameras are widely available, and are increasingly use in digital close-range photogrammetry. And photogrammetry instruments are developing rapidly and the precision is improving continuously. The building of 3D terrains of high precision are possible and the calculation of the areas or the earthwork volumes have high precision due to the development of the technique of the spatial information system using computer. Using the digital camera which has capacity of keeping numerical value by itself and easy carrying, we analyze the positioning error according to various change of photographing condition. Also we try to find a effective method of acquiring basis data for 3D modeling of high-accuracy in pixel degree through digital close-range photogrammetry with bundle adjustment for digital elevation model generation.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.44 no.1
• /
• pp.1-9
• /
• 2007

In this paper, we propose a new 3D modeling and rendering system using multiple stereo cameras. When target objects are captured by cameras, each capturing PC segments the objects and estimates disparity fields, then they transmit the segmented masks, disparity fields, and color textures of objects to a 3D modeling server. The modeling server generates 3D models of the objects from the gathered masks and disparity fields. Finally, the server generates a video at the designated point of view with the 3D model and texture information from cameras.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2005.05a
• /
• pp.1619-1622
• /
• 2005

본 논문에서는 로봇이 작업을 계획하기 위해 필요한 3차원 작업 공간을 세 가지의 컨텍스트(context)들을 이해함으로써 빠르게 모델링하는 새로운 기법을 소개 하고 있다. 로봇이 사람과 비슷한 속도와 정확도로 작업 공간을 이해하고 모델링하는 것에 초점을 두고 있으며 이를 위해 작업 공간상의 특징적인 세 가지의 컨텍스트(작업공간의 간략화를 위한 전체 공간상의 평면특징, 데이터베이스에 미리 정의된 물체 그리고 로봇의 주어진 작업에 따라 다양한 상세함을 갖는 그 외의 장애물)를 정의하였고, 그것들을 빠르게 이해함으로써 어떻게 3차원 작업 공간을 형성하는지 설명하고 있다. 본 논문에서 3 차원 정보를 갖는 scale invariant feature transformation(SIFT)를 stereo-sis SIFT 로 간주했으며 이를 이용하여 위에서 언급한 컨텍스트들을 이해하였고 다양한 카메라의 위치로부터 얻어지는 여러 개의 장면들을 정합하였다. 또한, 실험을 통해 제안한 방법의 타당성도 검증하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.27 no.4
• /
• pp.445-452
• /
• 2009

Through the Airbone LiDAR point, the study for three-dimensional modeling of the city zone has been in progress. So, deciding the Density of Airbone LiDAR point for that is very important to get a result of three-dimensional modeling of the city zone and make efficient use of airbone LiDAR. This study made the standard density to decide the optimum density of Airbone LiDAR point in the city zone. Through each standard density point of DSM and the outline of the buildings, It executed the visual evaluation and the accuracy inspection to decide the optimum density point, and presented the optimum density for the airbone LiDAR point in the city zone.

• Geophysics and Geophysical Exploration
• /
• v.3 no.1
• /
• pp.13-18
• /
• 2000

We describe the concept of the singularity in the integral equation of electromagnetic (EM) modeling in comparison with that in the integral representation of electric fields in EM theory, which would clarify the singular integral problems of the Green's tensor. We have also derived and classified the singular integrals of the Green's tensors in 3-D, 2.5-D and 2-D as well as in the thin sheet integral equations of the EM scattering problem, which have the most important effect on the accuracy of the numerical solution of the problems.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2006.11a
• /
• pp.223-226
• /
• 2006

가상현실 기술은 3 차원 가상공간 및 물체를 시각화하는데 중점을 두고 있다. 이는 사용자가 3 차원으로 데이터를 충분히 활용하지 못하고, 시각자료로만 사용하게 되는 요인이 된다. 이를 보완하기 위해 시각 정보뿐만 아니라 구조 및 관계에 대한 정보까지도 효과적으로 활용 할 수 있는 연구가 필요하다. 따라서 본 연구에서는 외형뿐만 아니라 내부적인 구조와 관계에도 의미를 부여하기 위하여 3 차원 건축물에 XML 기반의 토픽맵을 적용하였다. 전통 건축물의 공포 부분을 모델링하고, 각각의 객체가 사용자에 의해 조작이 가능하도록 하였으며, 객체들의 구조와 연결관계를 분석하고, 정의된 구조 및 관계를 토대로 토픽맵을 작성하였다. 작성된 토픽맵은 모델링 데이터에 적용 가능하도록 DOM 을 이용하여 변환하였다. 이 연구를 통해 아무리 복잡한 구조물이라도 그에 대한 구조 정보를 쉽게 파악할 수 있었고, 계층적 연결 관계도 쉽게 파악 할 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.2
• /
• pp.322-327
• /
• 2003

Based on dynamic muscle model to construct efficient face animation in this paper 30 face modelling techniques propose. Composed face muscle by faceline that connect 256 point and this point based on dynamic muscle model, and constructed wireframe because using this. After compose standard model who use wireframe, because using front side and side 2D picture, enforce texture mapping and created 3D individual face model. Used front side of characteristic points and side part for correct mapping, after make face that have texture coordinates using 2D coordinate of front side image and front side characteristic points, constructed face that have texture coordinates using 2D coordinate of side image and side characteristic points.

• Korean Journal of Remote Sensing
• /
• v.32 no.5
• /
• pp.511-527
• /
• 2016

We propose a rotating stereo frame camera system to acquire indoor images with a low cost. For experiments, we selected a test site and acquired images using the proposed system and control points using a total station. Using these data, we generated various indoor 3D models using commercial photogrammetric software, PhotoScan. We then performed qualitative and quantitative analysis of the generated indoor 3D models to investigate the possibility of the indoor modeling using the proposed system. From the results, it is confirmed that the generated indoor models using the proposed system can be applicable to the services not inquiring high accuracy.

• Journal of Korean Society for Geospatial Information Science
• /
• v.12 no.2 s.29
• /
• pp.37-42
• /
• 2004

The purpose of this study is not only preserving and restoring our nation's precious cultural inheritances transmitted for half millennia but informing the world of them. This study also aims recognizing the necessity of transmitting them to prosperity, constructing three-dimensional database by using a photogrammetry and VRML method and utilizing basic data of treasure exhibition with the progress of exhibition technique development on cyber space. Therefore, in this study, I suggest three dimensional modeling method that acquire three dimensional database about cultural properties through photogrammetry method which can acquire three-dimensional coordinates with easy and can express various color and stuff-feeling by using VRML.