• Title/Summary/Keyword: reduced basis

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A Neuro-Fuzzy Model Optimization Using Rough Set Theory (러프 집합이론을 이용한 뉴로-퍼지 모델의 최적화)

  • 연정흠;서재용;김용택;조현찬;전홍태
    • Journal of the Korean Institute of Intelligent Systems
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    • v.10 no.3
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    • pp.188-193
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    • 2000
  • This paper presents an approach to obtain a reduced neuro-fuzzy model for a plant. The Neuro-Fuzzy Network are compose of the Radial Basis Function Networks with Gausis membership and learned by using temporal back propagation. The dependency in rough set theory is used to eliminate rules. Dependency between the condition membership value of each rule in a model and the output of the plant can allow us to see how much contribution the rule is to identify the plant. While the reduced model maintains the same performance as the original one, the selection algorithm can minimize its complexity and redundancy of the structure.

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Reduced Scale Model Experiments and Numerical Simulation for Flow Uniformity in de-NOx SCR Reactor (배연탈질 SCR 반응기내 유동균일 화를 위한 축소모형실험 및 전산해석)

  • 이인영;김동화;이정빈;류경옥
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.4
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    • pp.347-354
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    • 2001
  • SCR (Selective Catalytic Reduction) process is presently considered as one of the most effective techniques for removing nitric oxides from exhaust gases. In this study, based on the conceptually designed SCR reactor of 500 MW coal fired power plant. a reduced scale (1/20) SCR reactor model was made to analyze the flow pattern in front of catalyst layer according to the guide vane's design factors such as the number, interval, and angle of vanes. The results of the test were compared to those numerical simulation in order to assure the reliability of two methods. On the basis of our study. the critical Reynolds number (2.0$\times$ 10$^{5}$ ) was proposed for ensuring the similarity between the reduced scale model and the prototype of SCR reactor. Optimum design parameters of guide vanes were determined as follows, 4 vanes, the first vane angle of 93$^{\circ}$, and the vane intervals of 0.85 S/n, 1.05 S/n, 1.1 S/n, 1.0S/n, 1.0S/n (S: the distance of duct, n: the number of guide vanes). The excellent agreement between the results of the numerical simulation and the reduced scale model provides the validation of two methods for prediction of flow through SCR reactor.

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A function space approach to study rank deficiency and spurious modes in finite elements

  • Sangeeta, K.;Mukherjee, Somenath;Prathap, Gangan
    • Structural Engineering and Mechanics
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    • v.21 no.5
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    • pp.539-551
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    • 2005
  • Finite elements based on isoparametric formulation are known to suffer spurious stiffness properties and corresponding stress oscillations, even when care is taken to ensure that completeness and continuity requirements are enforced. This occurs frequently when the physics of the problem requires multiple strain components to be defined. This kind of error, commonly known as locking, can be circumvented by using reduced integration techniques to evaluate the element stiffness matrices instead of the full integration that is mathematically prescribed. However, the reduced integration technique itself can have a further drawback - rank deficiency, which physically implies that spurious energy modes (e.g., hourglass modes) are introduced because of reduced integration. Such instability in an existing stiffness matrix is generally detected by means of an eigenvalue test. In this paper we show that a knowledge of the dimension of the solution space spanned by the column vectors of the strain-displacement matrix can be used to identify the instabilities arising in an element due to reduced/selective integration techniques a priori, without having to complete the element stiffness matrix formulation and then test for zero eigenvalues.

NUMERICAL SOLUTIONS OF BURGERS EQUATION BY REDUCED-ORDER MODELING BASED ON PSEUDO-SPECTRAL COLLOCATION METHOD

  • SEO, JEONG-KWEON;SHIN, BYEONG-CHUN
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.19 no.2
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    • pp.123-135
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    • 2015
  • In this paper, a reduced-order modeling(ROM) of Burgers equations is studied based on pseudo-spectral collocation method. A ROM basis is obtained by the proper orthogonal decomposition(POD). Crank-Nicolson scheme is applied in time discretization and the pseudo-spectral element collocation method is adopted to solve linearlized equation based on the Newton method in spatial discretization. We deliver POD-based algorithm and present some numerical experiments to show the efficiency of our proposed method.

Contents Analysis on the Rural Village Development Projects: With Focus on Project Regions during 2004-2007 (농촌마을종합개발사업 내용분석과 시사점 -'04-'07년 사업대상지 사업을 중심으로 -)

  • Park, Han-Sik;Hwang, Gil-Sik;Kim, Young-Taek
    • Journal of Korean Society of Rural Planning
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    • v.14 no.4
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    • pp.121-128
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    • 2008
  • The purpose of this study is to identify the trend of the contents of the plan that was implemented through contents analysis on the master plan project of rural village development projects that began in 2004. Contents analysis is based on the classification of business in the detailed enforcement regulations of rural village development project. Analysis on the project contents was conducted for 30 days from June 20 to July 20 for the 132 regions established in the master plan during the period from 2004 to 2007. The results of the analysis showed the following. First, scenery facilities, rural tourism, cultural welfare and income basis projects accounted for 76.5% of the total projects. Second, with regard to investment costs depending on the contents of the projects, cultural welfare, rural tourism and income basis projects accounted for 66.3% of the total investment costs. Third, it was found out that, with regard to the trend of change in the project contents by year, income basis projects were sharply reduced whereas cultural welfare and scenery facilities projects were increased. Finally, with regard to the analysis on the projects by region, it was found that Gangwon, Gyeonggi and Chungnam gave high weight on rural tourism, whereas Gyeongbuk, Jeonnam and Jeonbuk gave low weight on rural tourism. Particularly, Gyeongnam was found to have given low weight on income basis project.

Seismic response characteristics of base-isolated AP1000 nuclear shield building subjected to beyond-design basis earthquake shaking

  • Wang, Dayang;Zhuang, Chuli;Zhang, Yongshan
    • Nuclear Engineering and Technology
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    • v.50 no.1
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    • pp.170-181
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    • 2018
  • Because of the design and construction requirements, the nuclear structures need to maintain the structural integrity under both design state and extreme earthquake shaking. The base-isolation technology can significantly reduce the damages of structures under extreme earthquake events, and effectively protect the safeties of structures and internal equipment. This study proposes a base-isolation design for the AP1000 nuclear shield building on considering the performance requirements of the seismic isolation systems and devices of shield building. The seismic responses of isolated and nonisolated shield buildings subjected to design basis earthquake (DBE) shaking and beyond-design basis earthquake (BDBE) shaking are analyzed, and three different strategies for controlling the displacements subjected to BDBE shaking are performed. By comparing with nonisolated shield buildings, the floor acceleration spectra of isolated shield buildings, relative displacement, and base shear force are significantly reduced in high-frequency region. The results demonstrate that the base-isolation technology is an effective approach to maintain the structural integrity which subjected to both DBE and BDBE shaking. A displacement control design for isolation layers subjected to BDBE shaking, which adopts fluid dampers for controlling the horizontal displacement of isolation layer is developed. The effectiveness of this simple method is verified through numerical analysis.

Efficacy of Uniconazole as a Phytoprotectant Against $SO_2$ Injury in Snap Bean (강남콩에 대한 $SO_2$ 피해경감제로서 uniconazole의 효과에 관한 연구)

  • ;Donald T. Krizek;Roman M. Mirecki;Edward H. Lee
    • Journal of Korean Society for Atmospheric Environment
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    • v.8 no.1
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    • pp.13-19
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    • 1992
  • This study was conducted to determine the efficacy of using uniconazole,[(E)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazole-1-yl)-1-penten-3-ol)] as a phytoprotectant against $SO_2$ injury in snap been (Phaseolus vulgaris L. 'Strike'). Thirteen days prior to $SO_2$ fumigation, plants were given a 100 ml soil drench of uniconazole solution at concentrations of 0.02, 0.10, 0.25 and 0.50 mg/pot. All four uniconazole concentrations were significantly effective in providing protection against $SO_2$ exposure(3 h at 1.5 ppm), but uniconazole treatment above 0.02 mg/pot severely reduced stem elongation, leaf enlargement, flowering date and pod number and weight. Uniconazole treatment had little or no effect on stomatal conductance but reduced transpiration rate on a whole plant basis by nearly 40%. This may reflect an alteration in canopy structure by reducing stem elongation and leaf enlargement. Although uniconazole did not increase the activities of superoxide dismutase(SOD) and peroxidase(POD) in non-$SO_2$-fumigated plants, it significantly increased those enzyme activities in $SO_2$-fumigated plants. Chlorophyll concentration on the basis of unit area was increased 50-60% by uniconazole. However, the difference was not detected on the basis of dry weight. $SO_2$ increased variable chlorophyll fluorescence (Fv) 48% after 1.5 h of exposure in non-uniconazole treated plants but decreased Fv in the plants after 3 h of exposure. By appliing uniconazole, it was possible to maintain high Fv values in the latter group of plants. These results suggest that the phytoprotective effects of uniconazole are related to its growth-retarding properties as an anti-gibberellin as well as the increase of activites of free radical scavengers such as SOD and POD.

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An Efficient Computation Method of Zernike Moments Using Symmetric Properties of the Basis Function (기저 함수의 대칭성을 이용한 저니키 모멘트의 효율적인 계산 방법)

  • 황선규;김회율
    • Journal of KIISE:Software and Applications
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    • v.31 no.5
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    • pp.563-569
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    • 2004
  • A set of Zernike moments has been successfully used for object recognition or content-based image retrieval systems. Real time applications using Zernike moments, however, have been limited due to its complicated definition. Conventional methods to compute Zernike moments fast have focused mainly on the radial components of the moments. In this paper, utilizing symmetric/anti-symmetric properties of Zernike basis functions, we propose a fast and efficient method for Zernike moments. By reducing the number of operations to one quarter of the conventional methods in the proposed method, the computation time to generate Zernike basis functions was reduced to about 20% compared with conventional methods. In addition, the amount of memory required for efficient computation of the moments is also reduced to a quarter. We also showed that the algorithm can be extended to compute the similar classes of rotational moments, such as pseudo-Zernike moments, and ART descriptors in same manner.

A Study on the Electronic Payment Systems for International e-Business (국제전자상거래를 위한 전자결제시스템에 관한 연구)

  • 이내준
    • Journal of the Korea Computer Industry Society
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    • v.2 no.10
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    • pp.1339-1348
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    • 2001
  • This study is directed to compare the payment systems between conventional and internet, under international commerce. A stable and secure payment system is necessary for the progress of e-business through the internet. There are three typical methods of payment system in conventional transactions; the letter of credit(L/C) basis, the collection basis and the remittance basis. The exporter prefers L/C basis because of authentic payment, financial convenience and reduced risk Buyers and sellers who have enjoyed long creditable relationships use carefully the collection basis. The remittance basis is adequate for small amount payment for sample. In this paper, the merits and demerits of electronic payment system are compared to the conventional payment one. Internet payment system has an advantage of speed-up in payment against the conventional, but has a limited usage in the area of consumer based(B to C) transaction. The conventional payment system has been becoming overwhelm electronic payment one in the business to business(B to B) area.

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Reduced-order Parameter-dependent Robust $H_{\infty}$ Filtering for Discrete Uncertain Singular Systems (이산 불확실 특이시스템의 변수종속 차수축소 강인 $H_{\infty}$ 필터링)

  • Kim, Jong-Hae
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.48 no.5
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    • pp.59-65
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    • 2011
  • In this paper, we present a reduced-order parameter-dependent robust $H_{\infty}$ filter design method for discrete-time singular systems with polytopic uncertainties. A BRL(bounded real lemma) for parameter-dependent singular systems is derived from a parameter-dependent Lyapunov function. On the basis of the obtained BRL, low order robust $H_{\infty}$ filter design method is presented by polytopic approach, new reduced-order method, and LMI(linear matrix inequality) technique. Finally, a numerical example is presented to illustrated the feasibility of the proposed method.