• 한국군사과학기술학회지
• /
• 제14권6호
• /
• pp.1207-1214
• /
• 2011

Design of 500W class UMGT(Ultra Micro Gas Turbine) for power generation is conducted. Basic design parameters are obtained by cycle analysis. Off-design performances are predicted by 1D aerodynamic design and 1D performance analysis of compressor and turbine. 3D impellers are designed and 3D performance analysis is carried out to predict the performance characteristics of UMGT. 1D and 3D performance analysis show similar results. Structure analysis is conducted to select materials. Titanium Alloy is proposed for structural stability.

• 한국CDE학회논문집
• /
• 제11권3호
• /
• pp.172-182
• /
• 2006

This paper presents a method to convert 3D CAD model to an appropriate analysis model using wrap-around, smooth-out and thinning operators that have been originally developed to realize the multi-resolution modeling. Wrap-around and smooth-out operators are used to simplify 3D model, and thinning operator is to reduce the dimension of a target object with simultaneously decomposing the simplified 3D model to 1D or 2D shapes. By using the simplification and dimension-reduction operations in an appropriate way, the user can generate an analysis model that matches specific applications. The advantage of this method is that the user can create optimized analysis models of various simplification levels by selecting appropriate number of detailed features and removing them.

• 융합신호처리학회논문지
• /
• 제2권2호
• /
• pp.68-74
• /
• 2001

UHF 대역에서 동작하는 3db-커플러(Coupler)를 이용한 가변 감쇄기(Variable Attenuator)를 설계하고 제작한다. 가변 감쇄기를 구현하기 위하여 9$0^{\circ}C$, 3dB-커플러를 사용한다. 커플러를 이용한 가변 감쇄기의 동작 원리를 소개하고, 이에 대한 수학적 해석(Mathematical Analysis)을 통하여 가변 감쇄기 제작에 사용할 3dB 커플러를 시뮬레이션(Simulation) 등을 통하여 설계한다. PIN 다이오드(Diode)를 이용한 가변저항(Variable Resistor)를 시뮬레이션을 통하여 설계하고, 직접 제작하여 네트웍 분석기(Network Analyzer)를 통하여 측정하여 비교 분석한 결과 최저 삽입손실(Insertion Loss) -l0dB, 연속적인 가변 최대 감쇄(Attenuation) 10dB를 얻을 수 있다.

• Geomechanics and Engineering
• /
• 제17권4호
• /
• pp.317-322
• /
• 2019

This paper presents the results of parametric analyses to compute the axial capacity of a suction pile using 2D and 3D finite element approaches. The study is intended to simplify the process of analyzing suction piles from 3D to 2D model. The research focuses on obtaining the coefficient to be applied into the 2D model in order to obtain results that are as close as possible to the 3D model. Two 2D models were used in the analysis, namely the plane strain and axisymmetric models. The analyses were performed using two actual offshore soil data of the North and West Java Indonesia. The study reveals that the simplification of model through 2D Finite Element is achievable by applying the appropriate coefficient to the stiffness parameters. The results show that the simplified model of the 2D FEA provides more conservative results (with the difference between 2% to 7%) than the 3D FEA.

• 한국지반공학회논문집
• /
• 제40권6호
• /
• pp.21-32
• /
• 2024

대가야 시대에 축조된 고분의 안정성 평가를 위해서 터널 해석에 적용되는 수치해석 기법을 이용하여 연구를 수행하였다. 고령 고아리 벽화고분은 코벨 아치 구조로 축조되었으며 현실 석벽의 풍화로 인하여 배부름 현상 등 변위가 발생하고 있다. 우선 기존의 연구 결과와 비교를 통하여 아칭효과를 고려한 수치해석의 타당성을 검증한다. 3D 스캔 및 실측자료를 바탕으로 실제 고분과 유사하게 3차원 모델링을 수행하였다 그리고 검증된 해석 절차를 적용하여 3차원 수치해석을 수행하였다. 3차원 해석 결과를 통하여 취약 구간 검토 및 보강 방안을 합리적으로 수립하였고, 보강 단면에 대한 안정성 검토를 수행할 수 있었다.

• 한국디지털건축인테리어학회논문집
• /
• 제5권2호
• /
• pp.9-14
• /
• 2005

The analysis system has been needed to pre-evaluate and analyze the right for sunlight and the right for view in a residential environment since the urban high density and high rise residentinal building types have been prevailing these days. The purpose of this study is to propose an digital analysis method to evaluate sunlight and view conditions in a residential environment to improve the system performance in the sense of speed and accuracy. The digital analysis method using the object-oriented 3D CAD system and parametric library is studied and applied in the system and the various outputs of the analysis system makes possible to modify the design with the speed and accuracy as a result of the analysis. The study includes the evaluation for a daylight and view condition of each unit, and the interruption degree to a vicinity environment in terms of sunlight and view conditions comparing before and after construction.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1997년도 추계학술대회논문집
• /
• pp.49-52
• /
• 1997

The kinematically admissible velocity field is developed for the analysis of the curving of an eccentric extrusion. The curving of product in extrusion is caused by the difference of the linearly distributed longitudinal velocity on the cross-section of the workpiece at the dies exit. The result of the analysis show that the curvature of product increases with the increase in eccentricity of gravity center of the cross-section of the workpiece at the die entrance from that of the cross-section at the die exit. It also increase with the die land dimension. By the DEFORMTM-3D analysis, the curving of T-shaped product in extrusion is changed by the eccentricity, die land length and the friction constant. The result of the analysis by DEFORMTM-3D software shows that the curvature of circular shaped product increases with the eccentricity. The two analysis and one experiment show the curving phenomenon in eccentric extrusion process.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2001년도 봄 학술발표회 논문집
• /
• pp.347-354
• /
• 2001

In this study, 3-D FEM analysis are carried out to investigate the effect of the corners and re-entrant corners which can't be analysed by 2-D analysis. The excavation shape is re-entrant type conditions. The wall displacement, earth pressure and effectiveness of the corner struts are investigated in the re-entrant case, The 3D analysis are peformed to evaluate the effect of various factors, such as re-entrant corner size, excavation depth, and presence of struts. The wall displacement and earth pressures are influenced the size of re-entrant corner. Therefore, the effect of re-entrant corner should be considered in the evaluation of the earth pressure and displacement of the corners. Finally, strut-support systems are not effective at the re-entrant corner.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권5호
• /
• pp.2273-2286
• /
• 2018

This paper describes transformations between elemental image arrays and a RGBD image for three-dimensional integral imaging and transmitting systems. Two transformations are introduced and analyzed in the proposed method. Normally, a RGBD image is utilized in efficient 3D data transmission although 3D imaging and display is restricted. Thus, a pixel-to-pixel mapping is required to obtain an elemental image array from a RGBD image. However, transformations and their analysis have little attention in computational integral imaging and transmission. Thus, in this paper, we introduce two different mapping methods that are called as the forward and backward mapping methods. Also, two mappings are analyzed and compared in terms of complexity and visual quality. In addition, a special condition, named as the hole-free condition in this paper, is proposed to understand the methods analytically. To verify our analysis, we carry out experiments for test images and the results indicate that the proposed methods and their analysis work in terms of the computational cost and visual quality.

• Tribology and Lubricants
• /
• 제25권3호
• /
• pp.150-156
• /
• 2009

Precise leakage prediction for annular type seals of turbomachinery is necessary for enhancing their efficiency and various prediction methods have been developed. As the seal passage is designed intricately, the analysis based on Bulk-flow concept which has been mainly used in predicting seal leakage is limited. In order to improve the seal leakage prediction, full Navier-Stokes Equations with turbulent model derived in the seal flow passage have to be solved. In this study, 3D CFD (Computational Fluid Dynamics) analysis has been performed for predicting leakage of various non-contact type anular seals using FLUENT. Compared to the results by Bulk-flow model analysis, experiment, and 2D CFD analysis, the result of 3D CFD analysis shows improvement in predicting seal leakage, especially for the parallel grooved pump seal.