• 제목/요약/키워드: Non-uniform design

검색결과 370건 처리시간 0.026초

A Motion Compression Method by Min S-norm Composite Fuzzy Relational Equations

  • Nobuhara, Hajime;Hirota, Kaoru
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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    • pp.488-491
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    • 2003
  • A motion compression method by min s-norm composite fuzzy relational equations (dual-MCF) is proposed, where a motion sequence is divided into intra-pictures (I-pictures) and predictive-pictures (P-pictures). The I-pictures and the P-pictures are compressed by using uniform coders and non-uniform coders, respectively. A design method of non-uniform coders is proposed to perform an efficient compression and reconstruction of the P-pictures, based on the dual overlap level of fuzzy sets and a fuzzy equalization. An experiment using 10 P-pictures confirms that the root means square errors of the proposed method is decreased to 82.9% of that of the uniform coders, under the condition that the compression rate is 0.0055. An experiment of motion compression and reconstruction is also presented to confirm the effectiveness of the dual-MCF based on the non-uniform coders.

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Design of Scannable Non-uniform Planar Array Structure for Maximum Side-Lobe Reduction

  • Bae, Ji-Hoon;Kim, Kyung-Tae;Pyo, Cheol-Sig;Chae, Jong-Suk
    • ETRI Journal
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    • 제26권1호
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    • pp.53-56
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    • 2004
  • In this letter, we propose a novel design scheme for an optimal non-uniform planar array geometry in view of maximum side-lobe reduction. This is implemented by a thinned array using a genetic algorithm. We show that the proposed method can maintain a low side-lobe level without pattern distortion during beam steering.

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Thermal-fluid-structure coupling analysis for plate-type fuel assembly under irradiation. Part-I numerical methodology

  • Li, Yuanming;Yuan, Pan;Ren, Quan-yao;Su, Guanghui;Yu, Hongxing;Wang, Haoyu;Zheng, Meiyin;Wu, Yingwei;Ding, Shurong
    • Nuclear Engineering and Technology
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    • 제53권5호
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    • pp.1540-1555
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    • 2021
  • The plate-type fuel assembly adopted in nuclear research reactor suffers from complicated effect induced by non-uniform irradiation, which might affect its stress conditions, mechanical behavior and thermal-hydraulic performance. A reliable numerical method is of great importance to reveal the complex evolution of mechanical deformation, flow redistribution and temperature field for the plate-type fuel assembly under non-uniform irradiation. This paper is the first part of a two-part study developing the numerical methodology for the thermal-fluid-structure coupling behaviors of plate-type fuel assembly under irradiation. In this paper, the thermal-fluid-structure coupling methodology has been developed for plate-type fuel assembly under non-uniform irradiation condition by exchanging thermal-hydraulic and mechanical deformation parameters between Finite Element Model (FEM) software and Computational Fluid Dynamic (CFD) software with Mesh-based parallel Code Coupling Interface (MpCCI), which has been validated with experimental results. Based on the established methodology, the effects of non-uniform irradiation and fluid were discussed, which demonstrated that the maximum mechanical deformation with irradiation was dozens of times larger than that without irradiation and the hydraulic load on fuel plates due to differential pressure played a dominant role in the mechanical deformation.

여고생 교복 재킷 착용감과 만족도에 관한 연구 -신축성 재킷과 비신축성 재킷의 비교- (A Study on Wearing Sensations and Satisfaction of High School Girls Uniforms' Jacket - A Comparision between Jacket of Stretch- and Nonstretch-woven Fabric -)

  • 김점해;이영주
    • 한국생활과학회지
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    • 제13권1호
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    • pp.135-144
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    • 2004
  • The purpose of this study was to investigate the wearing sensation and satisfaction of high school girls winter uniform' jacket. The subject participated in the study were 599 high school girls attending four different schools. The fabrics were divided into two parts of stretch and non-stretch woven fabrics. The results were as follows: 1. The high school girls showed body image distortion that she recognized herself as fatter than her real body type. Especially, this was severe in the slim body type. 2. In the aspect of the satisfaction for uniforms' jacket made with stretch fabric and non-stretch woven fabric. the elastic fabric was more satisfied than the non-stretch one because its width and length was shorter and fitter than non-stretch one. 3. When they wore the school uniform jacket, the wearing sensation of one made with stretch and non-stretch woven fabrics showed significant differences in arms hole when raising hands, front bust when carrying backpack on their back, backs while studying at desks, the upper arms and the elbows. 4. As for the alteration of school uniform jacket, the non-stretch woven fabric was appeared to be altered more than the stretch one.

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Ultimate strength of stiffened panels subjected to non-uniform thrust

  • Anyfantis, Konstantinos N.
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제12권1호
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    • pp.325-342
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    • 2020
  • The current study is focused on the evaluation of the ultimate strength of stiffened panels found in ship hull structures that are subjected to combined uniaxial thrust, in-plane and out-of-plane bending moments. This loading condition, which is in general ignored when performing buckling checks, applies to representative control geometries (stiffener with attached plating) as a consequence of the linearly varying normal stresses along the ship's depth induced by the hull-girder vertical bending moment. The problem is generalized by introducing a non-uniform thrust described by a displacement ratio and rotation angle and by introducing the slenderness ratios, within the practical range of interest. The formed design space is explored through methods sourcing from Design of Experiments and by applying non-linear finite element procedures. Surrogate empirical models have been constructed through regression analysis and Response Surface Methods. An additional empirical model is provided to the literature for predicting the ultimate strength under uniaxial thrust. The numerical experimentation has shown that is a significant influence on the ultimate strength of stiffened panels as the thrust non-uniformity increases.

Power and Trim Estimation for Helicopter Sizing and Performance Analysis

  • Laxman, Vaitla;Lim, Jae-Hoon;Shin, Sang-Joon;Ko, Kwang-Ho;Jung, Sung-Nam
    • International Journal of Aeronautical and Space Sciences
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    • 제12권2호
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    • pp.156-162
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    • 2011
  • The preliminary design stage of helicopters consists of various operations and in each operation design several detailed analysis tasks are needed. The analysis tasks include performance and the required power estimation. In helicopter design, those are usually carried out by adopting the momentum theory. In this paper, an explicit form of computational analysis based on the blade element theory and uniform/non-uniform inflow model is developed. The other motivation of the present development is to obtain trim and required power estimation for various helicopter configurations. Sectional and hub loads, power, trim, and flapping equations are derived by using a symbolic tool. Iterative computations are carried out till convergence is achieved in the blade response, inflow, and trim. The predictions regarding the trim and power estimation turn out to be correlated well with the experimental results. The effect of inflow is further investigated. It is found that the present prediction for the lateral cyclic pitch angle is improved with the non-uniform inflow model as compared to that by the uniform inflow model. The presently improved trim and power estimation will be useful for future helicopter sizing and performance analysis.

Simulation and modeling for stability analysis of functionally graded non-uniform pipes with porosity-dependent properties

  • Peng Zhang;Jun Song;Tayebeh Mahmoudi
    • Steel and Composite Structures
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    • 제48권2호
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    • pp.235-250
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    • 2023
  • The present paper examines the stability analysis of the buckling differentiae of the small-scale, non-uniform porosity-dependent functionally graded (PD-FG) tube. The high-order beam theory and nonlocal strain gradient theory are operated for the mathematical modeling of nanotubes based on the Hamilton principle. In this paper, the external radius function is non-uniform. In contrast, the internal radius is uniform, and the cross-section changes along the tube length due to these radius functions based on the four types of useful mathematical functions. The PD-FG material distributions are varied in the radial direction and made with ceramics and metals. The governing partial differential equations (PDEs) and associated boundary conditions are solved via a numerical method for different boundary conditions. The received outcomes concerning different presented parameters are valuable to the design and production of small-scale devices and intelligent structures.

면내 압축력 및 바닥하중을 받는 플랫 플레이트의 설계 (Design of RC Flat Plate Subjected to Combined Axial Compressive and Floor Load)

  • 김재요;박홍근
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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    • pp.507-512
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    • 2000
  • This paper presents a design procedure using the moment magnifier method that is applicable to RC flat plates subjected to combined axial compressive and uniform or non-uniform floor load. Based on the numerical results, the design values of the buckling coefficient and the effective flexural rigidity, that define the buckling force, have been proposed. Using these design values, this paper provides the design procedure for the moment magnifier method.

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설계점 및 탈설계점에서 비균일 익단 간극을 가지는 축류 압축기의 유동장 예측 (Prediction of flow field in an axial compressor with a non-uniform tip clearance at the design and off-design conditions)

  • 강영석;박태춘;강신형
    • 한국유체기계학회 논문집
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    • 제11권6호
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    • pp.46-53
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    • 2008
  • Flow structures in an axial compressor with a non-uniform tip clearance were predicted by solving a simple prediction method. For more reliable prediction at the off-design condition, off-design flow characteristics such as loss and flow blockage were incorporated in the model. The predicted results showed that flow field near the design condition is largely dependent on the local tip clearance effect. However overall flow field characteristics are totally reversed at off-design condition, especially at the high flow coefficient. The tip clearance effect decreases, while the local loss and flow blockage make a complicated effect on the compressor flow field. The resultant fluid induced Alford's force has a negative value near the design condition and it reverses its sign as the flow coefficient increases and shows a very steep increase as the flow coefficient increases.

유전알고리즘을 이용한 비균일 하중을 받는 구조물의 지지 위치 최적화 연구 (Study of Supporting Location Optimization for a Structure under Non-uniform Load Using Genetic Algorithm)

  • 김근홍;이영신;김학근;허남일;사정우;양형렬;김병철;박주식
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1322-1327
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    • 2003
  • It is important to determine supporting locations for structural stability of a structure under non-uniform load in space interfered by other parts. In this case, There are many local optima with discontinuous design space. Therefore, The traditional optimization methods based on derivative are not suitable. Whereas, Genetic algorithm(GA) based on stochastic search technique is a very robust and general method. This paper has been presented to determine supporting locations of the vertical supports for reducing stress of the KSTAR(Korea super Superconducting Tokamak Advanced Research) IVCC(In-vessel control coil) under non-uniform electromagnetic load and space interfered by other parts using genetic algorithm. For this study, we develop a program combining finite element analysis with a genetic algorithm to perform structural analysis of IVCC. In addition, this paper presents a technique to perform optimization with FEM when design variables are trapped in an incongruent design space.

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