• Title/Summary/Keyword: Reduced System

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Reduction Method based on Sub-domain Structure using Reduced Pseudo Inverse Method (축소 의사역행렬을 이용한 영역분할 기반 축소모델 구축기법 연구)

  • Kim, Hyun-Gi;Cho, Maeng-Hyo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.2
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    • pp.173-179
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    • 2009
  • Reduction scheme is remarkably useful in the case requiring the repeated calculation procedure. Recently, the efficiency of the reduction scheme has been improved by combining scheme of sub-domain method. But, when the global domain is partitioned into a few sub-domains, sub-domains without constraints can be produced. it is needed to extract the ritz vector from each sub-domain to construct the reduced system of each sub-domain. it is easy to extract the ritz vector from sub-domain with constraint. on the other hand, pseudo inverse method should be employed to extract the ritz vector from sub-domain without constraint. generally, the pseudo inverse takes a large number of computing time to obtain a reduced system of a sub-domain without boundary condition. This trouble can be overcome by the reduced pseudo inverse scheme which proposed in this study. This scheme is based on the static condensation that is not related with selection of the primary degrees of freedom. Numerical examples demonstrate that present method saves computational cost effectively. In addition, it is shown that the reduced system based on the proposed scheme predicts the accurate eigenvalues of global system.

A Novel Hybrid Sequential Start Control System for Large Inductive Loads

  • Kim, Sang-Kon;Kim, Tae-Kon
    • Journal of Electrical Engineering and Technology
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    • v.10 no.1
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    • pp.388-394
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    • 2015
  • The inrush current of a large inductive load can be reduced with a soft starter; however, the large inrush current caused by simultaneous bulk starts (SBSs) cannot be effectively reduced. In order to reduce the high inrush current and voltage sag owing to the SBSs of large capacity inductive loads within a power network, a novel hybrid sequential start control system is proposed, implemented on embedded systems, and evaluated with a testbed in this study. From the experimental and simulation results of the proposed control system, the inrush current could be effectively restricted below the maximum current capacity of a power distributing board. Moreover, with the proposed system, power cost typically dictated by the peak power consumption can be fairly reduced, and the quality of the power system connected to the inductive loads can be efficiently increased.

Study on the Structural System Condensation using Multi-level Sub-structuring Scheme in Large-scale Problems (대형 시스템에서의 다단계 부분구조 기법을 이용한 시스템 축소기법에 관한 연구)

  • Baek, Sung-Min;Kim, Hyun-Gi;Cho, Meang-Hyo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.356-361
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    • 2008
  • Eigenvalue reduction schemes approximate the lower eigenmodes that represent the global behavior of the structures. In the previous study, we proposed a two-level condensation scheme (TLCS) for the construction of a reduced system. And we have improved previous TLCS with combination of the iterated improved reduced system method (IIRS) to increase accuracy of the higher modes intermediate range. In this study, we apply previous improved TLCS to multi-level sub-structuring scheme. In the first step, the global system is recursively partitioned into a hierarchy of sub-domain. In second step, each uncoupled sub-domain is condensed by the improved TLCS. After assembly process of each reduced sub-eigenvalue problem, eigen-solution is calculated by Lanczos method (ARPACK). Finally, Numerical examples demonstrate performance of proposed method.

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Low-Power Bus Architecture Composition for AMBA AXI

  • Na, Sang-Kwon;Yang, Sung;Kyung, Chong-Min
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.9 no.2
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    • pp.75-79
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    • 2009
  • A system-on-a-chip communication architecture has a significant impact on the performance and power consumption of modern multi-processors system-on-chips (MPSoCs). However, customization of such architecture for a specific application requires the exploration of a large design space. Thus, system designers need tools to rapidly explore and evaluate communication architectures. In this paper we present the method for application-specific low-power bus architecture synthesis at system-level. Our paper has two contributions. First, we build a bus power model of AMBA AXI bus communication architecture. Second, we incorporate this power model into a low-power architecture exploration algorithm that enables system designers to rapidly explore the target bus architecture. The proposed exploration algorithm reduces power consumption by 20.1% compared to a maximally connected reduced matrix, and the area is also reduced by 20.2% compared to the maximally connected reduced matrix.

A Reduced Equivalent model of the Catenary System (전차선로 시스템의 등가 축약 모델)

  • Lee Hanmin;Oh Kwanghae;Lee ChangMu;Han Moonseob;Chang shanghoon
    • Proceedings of the KSR Conference
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    • 2003.05a
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    • pp.415-420
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    • 2003
  • This paper estimates line constants of equivalent five-conductors model by using the reduced equivalent method. Actually, the catenary system is considered by the equivalent five-conductors model in the electrical aspect. Therefore, we should compose the catenary system of the equivalent five-conductors model. And then we calculate line constants of this equivalent five-conductors model. This paper shows the reducing process about the real system of the field by using the proposed theory and also line constants of reduced system

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Towards a reduced order model of battery systems: Approximation of the cooling plate

  • Szardenings, Anna;Hoefer, Nathalie;Fassbender, Heike
    • Coupled systems mechanics
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    • v.11 no.1
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    • pp.43-54
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    • 2022
  • In order to analyse the thermal performance of battery systems in electric vehicles complex simulation models with high computational cost are necessary. Using reduced order methods, real-time applicable model can be developed and used for on-board monitoring. In this work a data driven model of the cooling plate as part of the battery system is built and derived from a computational fluid dynamics (CFD) model. The aim of this paper is to create a meta model of the cooling plate that estimates the temperature at the boundary for different heat flow rates, mass flows and inlet temperatures of the cooling fluid. In order to do so, the cooling plate is simulated in a CFD software (ANSYS Fluent ®). A data driven model is built using the design of experiment (DOE) and various approximation methods in Optimus ®. The model can later be combined with a reduced model of the thermal battery system. The assumption and simplification introduced in this paper enable an accurate representation of the cooling plate with a real-time applicable model.

An LMI-Based Design of Reduced Order Observers Substitutable for Full Order Sliding Mode Observers (전차수 슬라이딩 모드 관측기를 대체하는 축소차수 관측기의 LMI 기반 설계)

  • Choi, Han-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.3
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    • pp.232-235
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    • 2008
  • This paper presents an LMI-based method to design reduced order observers by which we can substitute full order sliding mode observers for a class of uncertain time-delay systems. We show that a reduced order observer can be constructed as long as the uncertain system satisfies the previous LMI existence conditions of a full order sliding mode observer. And we give explicit formulas of the reduced order observer gain matrices. Finally, we give a simple LMI-based design algorithm, together with a numerical design example.

FUNCTIONS AND DIFFERENTIAL OPERATORS IN THE DUAL REDUCED QUATERNION FIELD

  • Jung, Hyun Sook;Shon, Kwang Ho
    • East Asian mathematical journal
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    • v.29 no.3
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    • pp.293-302
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    • 2013
  • We research properties of ternary numbers and hyperholomorphic functions with values in $\mathbb{C}$(2). We represent reduced quaternion numbers and obtain some propertries in dual reduced quaternion systems in view of Clifford analysis. Moreover, we obtain Cauchy theorems with respect to dual reduced quaternions.

Reductive Depolymerization of Bovine Thyroglobulin Multimers via Enzymatic Reduction of Protein Disulfide and Glutathiony­lated Mixed Disulfide Linkages

  • Liu Xi-Wen;Sok Dai-Eun
    • Archives of Pharmacal Research
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    • v.28 no.9
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    • pp.1065-1072
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    • 2005
  • The nascent thyroglobulin (Tg) multimer molecule, which is generated during the initial fate of Tg in ER, undergoes the rapid reductive depolymerization. In an attempt to determine the depolymerization process, various types of Tg multimers, which were generated from deoxy­cholate-treated/reduced Tg, partially unfolded Tg or partially unfolded/reduced Tg, were subjected to various GSH (reduced glutathione) reducing systems using protein disulfide isomerase (PDI), glutathione reductase (GR), glutaredoxin or thioredoxin reductase. The Tg multimers generated from deoxycholate-treated/reduced Tg were depolymerized readily by the PDI/GSH system, which is consistent with the reductase activity of PDI. The PDI/GSH-induced depolymerization of the Tg multimers, which were generated from either partially unfolded Tg or partially unfolded/reduced Tg, required the simultaneous inclusion of glutathione reductase, which is capable of reducing glutathionylated mixed disulfide (PSSG). This suggests that PSSG was generated during the Tg multimerization stage or its depolymerization stage. In particular, the thioredoxin/thioredoxin reductase system or glutaredoxin system was also effective in depolymerizing the Tg multimers generated from the unfolded Tg. Overall, under the net GSH condition, the depolymerization of Tg multimers might be mediated by PDI, which is assisted by other reductive enzymes, and the mechanism for depolymerizing the Tg multimers differs according to the type of Tg multimer containing different degrees and types of disulfide linkages.

Incorporating Performance Degradation in Fault Tolerant Control System Design with Multiple Actuator Failures

  • Zhang, Youmin;Jiang, Jin;Theilliol, Didier
    • International Journal of Control, Automation, and Systems
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    • v.6 no.3
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    • pp.327-338
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    • 2008
  • A fault tolerant control system design technique has been proposed and analyzed for managing performance degradation in the presence of multiple faults in actuators. The method is based on a control structure with a model reference reconfigurable control design in an inner loop and command input adjustment in an outer loop. The reduced dynamic performance requirements in the presence of different actuator faults are accounted for through different performance reduced (degraded) reference models. The degraded steady-state performances are governed by the reduced levels of command input. The reconfigurable controller is designed on-line automatically in an explicit model reference control framework so that the dynamics of the closed-loop system follow that of the performance reduced reference model under each fault condition. The reduced command input level is determined to prevent potential actuator saturation. The proposed method has been evaluated and analyzed using an aircraft example against actuator faults subject to constraints on the magnitude and slew-rate of actuators.