• 제목/요약/키워드: linear convergence

검색결과 1,329건 처리시간 0.033초

Linear Ion Beam Applications for Roll-to-Roll Metal Thin Film Coatings on PET Substrates

  • Lee, Seunghun;Kim, Do-Geun
    • Applied Science and Convergence Technology
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    • 제24권5호
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    • pp.162-166
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    • 2015
  • Linear ion beams have been introduced for the ion beam treatments of flexible substrates in roll-to-roll web coating systems. Anode layer linear ion sources (300 mm width) were used to make the linear ion beams. Oxygen ion beams having an ion energy from 200 eV to 800 eV used for the adhesion improvement of Cu thin films on PET substrates. The Cu thin films deposited by a conventional magnetron sputtering on the oxygen ion beam treated PET substrates showed Class 5 adhesion defined by ASTM D3359-97 (tape test). Argon ion beams with 1~3 keV used for the ion beam sputtering deposition process, which aims to control the initial layer before the magnetron sputtering deposition. When the discharge power of the linear ion source is 1.2 kW, static deposition rate of Cu and Ni were 7.4 and $3.5{\AA}/sec$, respectively.

선형 주기시스템의 제어 및 수치해석적 절차 수립에 관한 연구 (Development of the Numerical Procedures for the Control of Linear Periodic Systems)

  • 조장현
    • 한국정밀공학회지
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    • 제17권12호
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    • pp.121-128
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    • 2000
  • The scope of this paper is focused to the systems which have the time period and they should be necessarily studied in the sense of stability and design method of controller to stabilize the orignal unstable systems. In general, the time periodic systems or the systems having same motions during certain time interval are easily found in rotating motion device, i.e., satellite or helicopter and widely used in factory automation systems. The characteristics of the selected dynamic systems are analyzed with the new stability concept and stabilization control method based on Lyapunov direct method. The new method from Lyapunov stability criteria which satisfies the energy convergence is studied with linear algebraic method. And the numerical procedures are developed with computational programming method to apply to the practical linear periodic systems. The results from this paper demonstrate the usefulness in analysis of the asymptotic stability and stabilization of the unstable linear periodic system by using the developed simulation procedures.

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다중 UAV에 의해 획득된 거리 차 측정치를 이용한 순환 선형 강인 이동 표적추적 필터 (Recursive Linear Robust Moving Target Tracking Filter Using Range Difference Information Measured by Multiple UAVs)

  • 이혜경;나원상
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1738-1739
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    • 2011
  • In this paper, the range difference based the moving target tracking problem using multiple UAVs is solved within the new framework of linear robust state estimation. To do this, the relative kinematics is modeled as an uncertain linear system containing stochastic parametric uncertainties in its measurement matrix. Applying the non-conservative robust Kalman filter for the uncertain system, a quasi-optimal linear target tracking filter is designed. For its recursive linear filter structure, the proposed method can ensure the fast convergence and reliable target tracking performance. Moreover, it is suitable for real-time applications using multiple UAVs.

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A CHARACTERIZATION OF n-POSETS OF LD n - k WITH SIMPLE POSETS

  • Chae, Gab-Byung;Cheong, Minseok;Kim, Sang-Mok
    • 대한수학회보
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    • 제55권3호
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    • pp.777-788
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    • 2018
  • A simple poset is a poset whose linear discrepancy increases if any relation of the poset is removed. In this paper, we investigate more important properties of simple posets such as its width and height which help to construct concrete simple poset of linear discrepancy l. The simplicity of a poset is similar to the ld-irreducibility of a poset. Hence, we investigate which posets are both simple and ld-irreducible. Using these properties, we characterize n-posets of linear discrepancy n - k for k = 2, 3, and, lastly, we also characterize a poset of linear discrepancy 3 with simple posets and ld-irreducible posets.

신경회로망을 이용한 동적 시스템의 상태 공간 인식 모델에 관한 연구 (A Study on the State Space Identification Model of the Dynamic System using Neural Networks)

  • 이재현;강성인;이상배
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1997년도 추계학술대회 학술발표 논문집
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    • pp.115-120
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    • 1997
  • System identification is the task of inferring a mathematical description of a dynamic system from a series of measurements of the system. There are several motives for establishing mathematical descriptions of dynamic systems. Typical applications encompass simulation, prediction, fault diagnostics, and control system design. The paper demonstrates that neural networks can be used effective for the identification of nonlinear dynamical systems. The content of this paper concerns dynamic neural network models, where not all inputs to and outputs from the networks are measurable. Only one model type is treated, the well-known Innovation State Space model(Kalman Predictor). The identification is based only on input/output measurements, so in fact a non-linear Extended Kalman Filter problem is solved. Even for linear models this is a non-linear problem without any assurance of convergence, and in spite of this fact an attempt is made to apply the principles from linear models, an extend them to non-linear models. Computer simulation results reveal that the identification scheme suggested are practically feasible.

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THE LINEAR DISCREPANCY OF A PRODUCT OF TWO POSETS

  • Cheong, Minseok
    • 대한수학회보
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    • 제54권3호
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    • pp.1081-1094
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    • 2017
  • For a poset $P=(X,{\leq}_P)$, the linear discrepancy of P is the minimum value of maximal differences of all incomparable elements for all possible labelings. In this paper, we find a lower bound and an upper bound of the linear discrepancy of a product of two posets. In order to give a lower bound, we use the known result, $ld({\mathbf{m}}{\times}{\mathbf{n}})={\lceil}{\frac{mn}{2}}{\rceil}-2$. Next, we use Dilworth's chain decomposition to obtain an upper bound of the linear discrepancy of a product of a poset and a chain. Finally, we give an example touching this upper bound.

Theoretical Derivation of Minimum Mean Square Error of RBF based Equalizer

  • Lee Jung-Sik
    • 한국통신학회논문지
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    • 제31권8C호
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    • pp.795-800
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    • 2006
  • In this paper, the minimum mean square error(MSE) convergence of the RBF equalizer is evaluated and compared with the linear equalizer based on the theoretical minimum MSE. The basic idea of comparing these two equalizers comes from the fact that the relationship between the hidden and output layers in the RBF equalizer is also linear. As extensive studies of this research, various channel models are selected, which include linearly separable channel, slightly distorted channel, and severely distorted channel models. In this work, the theoretical minimum MSE for both RBF and linear equalizers were computed, compared and the sensitivity of minimum MSE due to RBF center spreads was analyzed. It was found that RBF based equalizer always produced lower minimum MSE than linear equalizer, and that the minimum MSE value of RBF equalizer was obtained with the center spread which is relatively higher(approximately 2 to 10 times more) than variance of AWGN. This work provides an analytical framework for the practical training of RBF equalizer system.

Noninformative priors for linear function of parameters in the lognormal distribution

  • Lee, Woo Dong;Kim, Dal Ho;Kang, Sang Gil
    • Journal of the Korean Data and Information Science Society
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    • 제27권4호
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    • pp.1091-1100
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    • 2016
  • This paper considers the noninformative priors for the linear function of parameters in the lognormal distribution. The lognormal distribution is applied in the various areas, such as occupational health research, environmental science, monetary units, etc. The linear function of parameters in the lognormal distribution includes the expectation, median and mode of the lognormal distribution. Thus we derive the probability matching priors and the reference priors for the linear function of parameters. Then we reveal that the derived reference priors do not satisfy a first order matching criterion. Under the general priors including the derived noninformative priors, we check the proper condition of the posterior distribution. Some numerical study under the developed priors is performed and real examples are illustrated.

Regional Linear Warping for Image Stitching with Dominant Edge Extraction

  • Yoo, Jisung;Hwang, Sung Soo;Kim, Seong Dae;Ki, Myung Seok;Cha, Jihun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제7권10호
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    • pp.2464-2478
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    • 2013
  • Image stitching techniques produce an image with a wide field-of-view by aligning multiple images with a narrow field-of-view. While conventional algorithms successfully stitch images with a small parallax, structure misalignment may occur when input images contain a large parallax. This paper presents an image stitching algorithm that aligns images with a large parallax by regional linear warping. To this end, input images are first approximated as multiple planar surfaces, and different linear warping is applied to each planar surface. For approximating input images as multiple planar surfaces, the concept of dominant edges is introduced. Dominant edges are defined as conspicuous edges of lines in input images, and extracted dominant edges identify the boundaries of each planar surface. Dominant edge extraction is conducted by detecting distinct changes of local characteristics around strong edge pixels. Experimental results show that the proposed algorithm successfully stitches images with a large parallax without structure misalignment.

등가하중법을 이용한 비선형 반응 구조최적설계 사례연구 (Case Studies of Nonlinear Response Structural Optimization Using Equivalent Loads)

  • 김용일;박경진
    • 대한기계학회논문집A
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    • 제31권11호
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    • pp.1059-1068
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    • 2007
  • Nonlinear response structural optimization is performed using equivalent loads (NROEL). Nonlinear response optimization is extremely cost because many nonlinear analyses are required. In NROEL, the external loads are transformed to the equivalent loads (EL) for linear static analysis and linear response optimization is carried out based on the EL in a cyclic manner until the convergence criteria are satisfied. EL is the load set which generates the same response field of linear analysis as that of nonlinear analysis. The primitive from of theory has been published. In this research, the theory is investigated with large scale example problems. Four examples are solved by using NROEL. Conventional optimization with sensitivity analysis using the finite difference method (FDM) is also applied to the same examples. Moreover, response surface optimization method is applied to the last two examples. The results of the optimizations are compared. In nonlinear response optimization of large scale problems, hundreds (or even thousands) of nonlinear analyses are expected to satisfy the convergence criteria. However, in nonlinear response optimization using equivalent loads, only tens of nonlinear analyses are required. The results are discussed and the usefulness of NROEL is presented.