• Title/Summary/Keyword: Overlapping decomposition technique

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Decetralized Control of Multiple Satellites Formation Flying Based on the Overlapping Decomposition Technique (중복 분해 기법을 이용한 인공위성 편대 비행의 분산제어)

  • Lee, Ho-Jae;Kim, Do-Wan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.7
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    • pp.1014-1018
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    • 2012
  • This paper presents a decentralized controller design for formation flying of multiple satellites based on the overlapping decomposition technique. Each satellite is assumed to avail only the information of its own and in front of itself, which restricts the structure of a controller gain matrix to an overlapped form. The concerned large-scale system is expanded using the overlapping decomposition technique. Design condition is represented in terms of linear matrix inequalities with small-scale systems in a decentralized form, based on the expanded system. The resulting controller is contracted to the original overlapped form so as to close the original system. A numerical simulation shows the effectiveness of the proposed technique.

Decentralized Load-Frequency Control of Large-Scale Nonlinear Power Systems: Fuzzy Overlapping Approach

  • Lee, Ho-Jae;Kim, Do-Wan
    • Journal of Electrical Engineering and Technology
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    • v.7 no.3
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    • pp.436-442
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    • 2012
  • This paper develops a design methodology of a decentralized fuzzy load-frequency controller for a large-scale nonlinear power system with valve position limits on governors. The concerned system is locally exactly modeled in Takagi-Sugeno's form. Sufficient design condition for uniform ultimate boundedness of the closed-loop system is derived based on the overlapping decomposition. Convergence of all incremental frequency deviations to zero is also investigated. A simulation result is provided to visualize the effectiveness of the proposed technique.

Effective Decentralized Sampled-Data Control for Nonlinear Systems in T-S' Form: Overlapping IDR Approach (타카기-수게노 형태의 비선형 시스템의 효율적 분산 샘플치 제어: 중복 지능형 디지털 재설계 접근법)

  • Lee, Ho-Jae;Kim, Do-Wan
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.1
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    • pp.94-99
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    • 2012
  • This paper discusses a decentralized sampled-data control problem for large-scale nonlinear systems. The system is represented in Takagi-Sugeno's form. Next, we design a decentralized analog controller based on the overlapping decomposition technique. The final step is to apply the intelligent digital redesign scheme for converting the analog controller into the sampled-data one. Design condition is represented in terms of linear matrix inequalities. A simulation result is provided for the effectiveness of the proposed design method.

A PARALLEL FINITE ELEMENT ALGORITHM FOR SIMULATION OF THE GENERALIZED STOKES PROBLEM

  • Shang, Yueqiang
    • Bulletin of the Korean Mathematical Society
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    • v.53 no.3
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    • pp.853-874
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    • 2016
  • Based on a particular overlapping domain decomposition technique, a parallel finite element discretization algorithm for the generalized Stokes equations is proposed and investigated. In this algorithm, each processor computes a local approximate solution in its own subdomain by solving a global problem on a mesh that is fine around its own subdomain and coarse elsewhere, and hence avoids communication with other processors in the process of computations. This algorithm has low communication complexity. It only requires the application of an existing sequential solver on the global meshes associated with each subdomain, and hence can reuse existing sequential software. Numerical results are given to demonstrate the effectiveness of the parallel algorithm.

A Study on the Construction of Modern Architectural Form and the Characteristics of Deconstructional Fashion (현대 건축의 형태구성과 해체주의 패션의 특성에 관한 연구)

  • 김혜정;임영자
    • Journal of the Korean Society of Costume
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    • v.40
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    • pp.137-147
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    • 1998
  • Fahion as the form construction of decon-structivistic architecture was analyzed by dividing it into the intrinsic aspect and the formal aspect through an introduction of three characteristic architectural principles into fashion. Intrinsic deconstructivistic fashion as the construction of architectural form has the mixurte of genders both in a form of transvestic and in a form of genderless look as dualism, and can be characterized by pluralistic nationlism with the emergence of the Third World alienated from the international society, and so forth. Difference and the prefixes of dis-and de- are schizophrenic mystic illusionism, chance effect and the differance of space and time and is supporting Jacques Derrida's chiasmus that is the perspective of collage in painting and the multiple observation of collage in painting and the multiple observation point as the play of borrowing the surrealistic technique. The formal construction of deconstructivistic fashion the construction of architectural form has intertextuality material, hybridization of items and the blending of modes and another sphere. Trace as icon deconstrucion attains historical analysis. Dis and de in fashion are showing the retrogre-ssion of gravity through decomposition, decon-tinuity and disjunction emerge nonstructural silho-uette, juxtaposition, inversion and replace- ment of underwear and outer garments. Their decentring expression emerged as construction through mixture and repetition as well as overlapping of planes or spaces. And their disjuctive representation appeared in the form of mutual juxtaposition and substitution with the double-side of formal construction in functional terms.

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Application of Multispectral Remotely Sensed Imagery for the Characterization of Complex Coastal Wetland Ecosystems of southern India: A Special Emphasis on Comparing Soft and Hard Classification Methods

  • Shanmugam, Palanisamy;Ahn, Yu-Hwan;Sanjeevi , Shanmugam
    • Korean Journal of Remote Sensing
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    • v.21 no.3
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    • pp.189-211
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    • 2005
  • This paper makes an effort to compare the recently evolved soft classification method based on Linear Spectral Mixture Modeling (LSMM) with the traditional hard classification methods based on Iterative Self-Organizing Data Analysis (ISODATA) and Maximum Likelihood Classification (MLC) algorithms in order to achieve appropriate results for mapping, monitoring and preserving valuable coastal wetland ecosystems of southern India using Indian Remote Sensing Satellite (IRS) 1C/1D LISS-III and Landsat-5 Thematic Mapper image data. ISODATA and MLC methods were attempted on these satellite image data to produce maps of 5, 10, 15 and 20 wetland classes for each of three contrast coastal wetland sites, Pitchavaram, Vedaranniyam and Rameswaram. The accuracy of the derived classes was assessed with the simplest descriptive statistic technique called overall accuracy and a discrete multivariate technique called KAPPA accuracy. ISODATA classification resulted in maps with poor accuracy compared to MLC classification that produced maps with improved accuracy. However, there was a systematic decrease in overall accuracy and KAPPA accuracy, when more number of classes was derived from IRS-1C/1D and Landsat-5 TM imagery by ISODATA and MLC. There were two principal factors for the decreased classification accuracy, namely spectral overlapping/confusion and inadequate spatial resolution of the sensors. Compared to the former, the limited instantaneous field of view (IFOV) of these sensors caused occurrence of number of mixture pixels (mixels) in the image and its effect on the classification process was a major problem to deriving accurate wetland cover types, in spite of the increasing spatial resolution of new generation Earth Observation Sensors (EOS). In order to improve the classification accuracy, a soft classification method based on Linear Spectral Mixture Modeling (LSMM) was described to calculate the spectral mixture and classify IRS-1C/1D LISS-III and Landsat-5 TM Imagery. This method considered number of reflectance end-members that form the scene spectra, followed by the determination of their nature and finally the decomposition of the spectra into their endmembers. To evaluate the LSMM areal estimates, resulted fractional end-members were compared with normalized difference vegetation index (NDVI), ground truth data, as well as those estimates derived from the traditional hard classifier (MLC). The findings revealed that NDVI values and vegetation fractions were positively correlated ($r^2$= 0.96, 0.95 and 0.92 for Rameswaram, Vedaranniyam and Pitchavaram respectively) and NDVI and soil fraction values were negatively correlated ($r^2$ =0.53, 0.39 and 0.13), indicating the reliability of the sub-pixel classification. Comparing with ground truth data, the precision of LSMM for deriving moisture fraction was 92% and 96% for soil fraction. The LSMM in general would seem well suited to locating small wetland habitats which occurred as sub-pixel inclusions, and to representing continuous gradations between different habitat types.