• Computers and Concrete
• /
• 제4권1호
• /
• pp.67-82
• /
• 2007

The discrete crack-concept is applied to study the 3D propagation of tensile-dominated failure in plain concrete. To this end the Partition of Unity Finite Element Method (PUFEM) is utilized and the strong discontinuity approach is followed. A consistent linearized implementation of the PUFEM is combined with a predictor-corrector algorithm to track the crack path, which leads to a robust numerical description of concrete cracking. The proposed concept is applied to study concrete failure during the PCT3D test and the predicted numerical results are compared to experimental data. The proposed numerical concept provides a clear interface for constitutive models and allows an investigation of their impact on concrete cracking under 3D conditions, which is of significant scientific interests to interpret results from 3D experiments.

• Journal of information and communication convergence engineering
• /
• 제19권2호
• /
• pp.102-107
• /
• 2021

In this paper, we propose a new three-dimensional (3D) photon-counting integral imaging reconstruction method using a merging reconstruction process and maximum likelihood estimation (MLE). The conventional 3D photon-counting reconstruction method extracts photons from elemental images using a Poisson random process and estimates the scene using statistical methods such as MLE. However, it can reduce the photon levels because of an average overlapping calculation. Thus, it may not visualize 3D objects in severely low light environments. In addition, it may not generate high-quality reconstructed 3D images when the number of elemental images is insufficient. To solve these problems, we propose a new 3D photon-counting merging reconstruction method using MLE. It can visualize 3D objects without photon-level loss through a proposed overlapping calculation during the reconstruction process. We confirmed the image quality of our proposed method by performing optical experiments.

• 패션비즈니스
• /
• 제15권3호
• /
• pp.97-111
• /
• 2011

This study aims to apply 3D virtual fabric parameters - as obtained from previous research experiments - to 3D virtual clothing simulation in comparing its similarity with actual clothing as worn, with a view to verifying the objectivity and validity of the 3D virtual fabric simulation method devised by the drape image analysis method. In addition, the result is intended to be used as the basic data for new 3D virtual clothing simulation methods. As the results, 3D virtual fabric parameters designed to simulate 3D drape to be similar to actual fabrics were found to be Bending Strength, Buckling Point, Density, Particle Distance, and Shear. They were also found to be important measurements when evaluating visual similarity between drape shadow images and number of nodes. 3D virtual fabric simulation method devised by the drape image analysis method was appropriate in extracting 3D fabric parameters with the reflection of actual fabrics' physical and dynamic characteristics, in connection with 3D virtual fabric simulation. 3D virtual fabric parameters with the reflection of actual fabrics' physical and dynamic characteristics using the proposed 3D virtual fabric simulation method are accumulated and provided as a standard, this will facilitate the introduction 3D virtual fabric simulation technology.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 B
• /
• pp.808-810
• /
• 2002

Higher current-rating and improved thermal performance are being sought for existing medium-voltage vacuum circuit breakers(VCB) in order to meet market needs which require to be compact and downsized. In this paper, thermal performance of medium voltage vacuum circuit breaker was investigated through experiments and numerical analysis. We changed several major parameters of current-rating and heat sink affecting on thermal behaviors in the breaker and observed the results. To predict the temperature distribution in complex three-dimensional (3-D) VCB components and gas, the commercial package was used to simulate conjugate heat transfer. Although some assumptions and simplifications were introduced to simulate the model, results from the computational model were in good agreement with actual temperature rise measurements obtained from experiments.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 B
• /
• pp.882-884
• /
• 2003

In this paper, thermal analysis of Cubicle type Gas Insulated Switchgear(C-GIS) was investigated through experiments and numerical analysis. To predict 3-dimensional temperature and velocity distribution, the commercial package was used. Although some assumptions and simplifications were introduced to simulate the model, results from the computational model were in good agreement with actual temperature rise measurements obtained from experiments.

• Journal of Information Technology Applications and Management
• /
• 제19권1호
• /
• pp.13-24
• /
• 2012

Usability and knowledge drawn from utilizing various ways of representing accounting data were examined. Classroom experiments were conducted to compare students' assessment of financial data using table of numbers, 2-dimensional column graphs (2D), 3-dimensional column graphs (3D), and mixed reality visualization of true 3-dimensional graphs (MR). The results showed that in assessing the financial status and performance of a firm, Table of numbers and MR took longer than 2D and 3D graphs. The time spent on true 3D graphs using MR technology was about the same as Table of numbers. When compared the assessment scores of the firm's financial status and performance between participants and experts, the difference was the least when participants used 2D graphs. However, MR was seen as being a new way to provide data of greater complexity and was very useful for financial information.

• Journal of the Optical Society of Korea
• /
• 제18권3호
• /
• pp.225-229
• /
• 2014

A reflection-type three-dimensional (3D) screen using retroreflector is proposed to improve the visibility of a projected 3D image while keeping its perspective. For the projection-type 2D display, the diffuser is used to represent the 2D scene, overcoming the limitation of the aperture of the projection lens set. If the diffuser is adopted for the projected 3D image, only 2D images sectioned and blurred should be displayed on the screen. The proposed screen can make the 3D image with the aperture limitation visible to be applied to the 3D image projection systems. The feasibility of the proposed screen is verified by experiments.

• 한국정보통신학회논문지
• /
• 제16권9호
• /
• pp.2037-2042
• /
• 2012

Synthetic aperture 집적 영상 (SAII) 기술은 다수의 카메라를 이용하여 고해상도의 요소 영상을 획득할 수 있는 유망한 3D 이미징 기술이다. 본 논문에서는 SAII 기술을 이용하여 집적 영상 디스플레이를 수행하는 공간 3D 영상을 표시하는 방법을 제안한다. SAII로부터 얻어지는 요소 영상은 직접적으로 공간 3D 영상으로 사용될 수 없기 때문에 깊이 지도를 추출하여 새로운 디스플레이용 요소 영상으로 변환하여 공간 3D 영상을 표시한다. 제안하는 방법의 유용함을 보이기 위해서 장난감 3D 물체를 사용하여 기초적인 실험을 수행하고, 또한 공간 3D 영상이 구현된 실험 결과를 제시한다.

• 한국가금학회:학술대회논문집
• /
• 한국가금학회 2000년도 제17차 정기총회 및 학술발표
• /
• pp.36-53
• /
• 2000

Five experiments were conducted to investigate the effects of antioxidants(Santoquin and Oxiban) using fresh or oxidized fat on the performance of broiler chicks. Day-old broiler chicks (except for Experiment 5 in which 6-d-ol birds were given experimental diets for 10 d) were fed diets containing fresh or oxidized fat (animal-vegetable fat blend in Experiments 1, 4, and 5 and corn oil in Experiments 2 and 3) with or without graded concentrations of Santoquin (0,250, 500 ppm in Experiments 1 and 2 and 0, in Experiment 4 and 400 ppm with 0.1% lipase in Experiment 5) of 2wk. In all experiments, birds fed fresh fat gained more weight, had better feed/gain, together with higher AME$_{n}$ and apparent fat digestibility (Experiments 1 and 2) than birds fed oxidized fat(P<0.05). There was no interaction among fat sources and antioxidants on the performance of chicks in any experiment. In Experiment 3, Santoquin more than 200 ppm resulted in a reduction in weight gain and feed intake(P<0.05). The livers of chicks fed oxidized fat in Experiments 2 and 5 had higher malondialdehyde (MDA) values (P<0.05) Chicks fed oxidized fat with 250 ppm Santoquin in Experiment 2 had lower liver MDA values, although this situation did not occur in Experiments 1, 4, and 5. These results indicate that antioxidant supplements can alleviate most deleterious effects of feeding oxidized fat and that supplementation of Santoquin more than 200 ppm has a negative effect on the performance of broiler chicks.s.

• Structural Engineering and Mechanics
• /
• 제2권3호
• /
• pp.227-244
• /
• 1994

The purpose of this investigation is to propose a numerical simulation method of the crack propagation behavior in 3-dimensionl elastic body. The simulation method is based on the displacement-type finite element method, and the linear fracture theory is introduced. The results from the proposed method are compared with those from the structural experiments, and the good coincidences between them are shown in this paper. At the same time, 2-dimensional analysis is also done, and the results are compared with those obtained from 3-dimensional analysis and the structural experiments.