• Title/Summary/Keyword: Multi-Domain Problem

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Analysis of Multi-Layered Structural Systems Using Nonlinear Finite Elements-Boundary Elements (반무한 다중 구조계의 비선형 유한요소 - 경계요소 해석)

  • 김문겸;장정범;이상도;황학주
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1992.04a
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    • pp.58-64
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    • 1992
  • It is usual that underground structures are constructed within multi-layered medium. In this paper, an efficient numerical model ling of multi-layered structural systems is studied using coupled analysis of finite elements and boundary elements. The finite elements are applied to the area in which the material nonlinearity is dominated, and the boundary elements are applied to the far field area where the nonlinearity is relatively weak. In the boundary element model 1 ins of the multi-layered medium, fundamental solutions are restricted. Thus, methods which can utilize existing Kelvin and Melan solution are sought for the interior multi-layered domain problem and semi infinite domain problem. Interior domain problem which has piecewise homogeneous layers is analyzed using boundary elements with Kelvin solution; by discretizing each homogeneous subregion and applying compatibility and equilibrium conditions between interfaces. Semi-infinite domain problem is analyzed using boundary elements with Melan solution, by superposing unit stiffness matrices which are obtained for each layer by enemy method. Each methodology is verified by comparing its results which the results from the finite element analysis and it is concluded that coupled analysis using boundary elements and finite elements can be reasonable and efficient if the superposition technique is applied for the multi-layered semi-infinite domain problems.

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Multiple Fusion-based Deep Cross-domain Recommendation (다중 융합 기반 심층 교차 도메인 추천)

  • Hong, Minsung;Lee, WonJin
    • Journal of Korea Multimedia Society
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    • v.25 no.6
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    • pp.819-832
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    • 2022
  • Cross-domain recommender system transfers knowledge across different domains to improve the recommendation performance in a target domain that has a relatively sparse model. However, they suffer from the "negative transfer" in which transferred knowledge operates as noise. This paper proposes a novel Multiple Fusion-based Deep Cross-Domain Recommendation named MFDCR. We exploit Doc2Vec, one of the famous word embedding techniques, to fuse data user-wise and transfer knowledge across multi-domains. It alleviates the "negative transfer" problem. Additionally, we introduce a simple multi-layer perception to learn the user-item interactions and predict the possibility of preferring items by users. Extensive experiments with three domain datasets from one of the most famous services Amazon demonstrate that MFDCR outperforms recent single and cross-domain recommendation algorithms. Furthermore, experimental results show that MFDCR can address the problem of "negative transfer" and improve recommendation performance for multiple domains simultaneously. In addition, we show that our approach is efficient in extending toward more domains.

Car Interior and Exterior Multi-domain Noise Analysis using Power Flow Boundary Element Method (PFBEM을 이용한 자동차 실내외 다영역 공간의 소음해석)

  • Kim, Jong-Do;Hong, Suk-Yun;Lee, Ho-Won;Kwon, Hyun-Wung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.489-493
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    • 2007
  • Mmulti-domain noise analysis method using Power Flow Boundary Element Method(PFBEM) has been developed successfully. Some applications are introduced. several examples. PFBEM is a numerical analysis method formulated by applying Boundary Element Method(BEM) to Power Flow Analysis(PFA). PFBEM is very powerful in predicting noise level in medium-to-high frequency ranges. However there are restrictions in analyzing the coupled structures and multi-media. In this paper, an analysis method for multi-domain acoustic problems in the diverse acoustic fields is suggested. And the developed method is applied to the car interior and exterior multi-domain noise analysis.

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Controller Backup and Replication for Reliable Multi-domain SDN

  • Mao, Junli;Chen, Lishui;Li, Jiacong;Ge, Yi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.12
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    • pp.4725-4747
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    • 2020
  • Software defined networking (SDN) is considered to be one of the most promising paradigms in the future. To solve the scalability and performance problem that a single and centralized controller suffers from, the distributed multi-controller architecture is adopted, thus forms multi-domain SDN. In a multi-domain SDN network, it is of great importance to ensure a reliable control plane. In this paper, we focus on the reliability problem of multi-domain SDN against controller failure from perspectives of backup controller deployment and controller replication. We firstly propose a placement algorithm for backup controllers, which considers both the reliability and the cost factors. Then a controller replication mechanism based on shared data storage is proposed to solve the inconsistency between the active and standby controllers. We also propose a shared data storage layout method that considers both reliability and performance. Besides, a fault recovery and repair process is designed based on the controller backup and shared data storage mechanism. Simulations show that our approach can recover and repair controller failure. Evaluation results also show that the proposed backup controller placement approach is more effective than other methods.

Multi-Impedance Change Localization of the On-Voltage Power Cable Using Wavelet Transform Based Time-Frequency Domain Reflectometry (웨이블릿 변환 기반 시간-주파수 영역 반사파 계측법을 이용한 활선 상태 전력 케이블의 중복 임피던스 변화 지점 추정)

  • Lee, Sin Ho;Choi, Yoon Ho;Park, Jin Bae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.5
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    • pp.667-672
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    • 2013
  • In this paper, we propose a multi-impedance changes localization method of on-voltage underground power cable using the wavelet transform based time-frequency domain reflectometry (WTFDR). To localize the impedance change in on-voltage power cable, the TFDR is the most suitable among reflectometries because the inductive coupler is used to inject the reference signal to the live cable. At this time, the actual on-voltage power cable has multi-impedance changes such as the automatic section switches and the auto load transfer switches. However, when the multi-impedance changes are generated in the close range, the conventional TFDR has the cross term interference problem because of the nonlinear characteristics of the Wigner-Ville distribution. To solve the problem, the wavelet transform (WT) is used because it has the linearity. That is, using WTFDR, the cross term interference is not generated in multi-impedance changes due to the linearity of the WT. To confirm the effectiveness and accuracy of the proposed method, the actual experiments are carried out for the on-voltage underground power cable.

Domain Adaptation Image Classification Based on Multi-sparse Representation

  • Zhang, Xu;Wang, Xiaofeng;Du, Yue;Qin, Xiaoyan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.5
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    • pp.2590-2606
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    • 2017
  • Generally, research of classical image classification algorithms assume that training data and testing data are derived from the same domain with the same distribution. Unfortunately, in practical applications, this assumption is rarely met. Aiming at the problem, a domain adaption image classification approach based on multi-sparse representation is proposed in this paper. The existences of intermediate domains are hypothesized between the source and target domains. And each intermediate subspace is modeled through online dictionary learning with target data updating. On the one hand, the reconstruction error of the target data is guaranteed, on the other, the transition from the source domain to the target domain is as smooth as possible. An augmented feature representation produced by invariant sparse codes across the source, intermediate and target domain dictionaries is employed for across domain recognition. Experimental results verify the effectiveness of the proposed algorithm.

Efficient Task Execution Methods in Multi-Agent Systems (멀티 에이전트 시스템에서의 효율적인 작업 수행 방법)

  • 박정훈;최중민
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.511-514
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    • 1998
  • This paper proposes efficient methods that integrate and execute local plan rules of task agents in a multi-agent environment. In these methods, each agent's plan rules are represented in a network structure, and these networks are then collected by a single task agent to build a integrated domain network, which is exploited to achieve the goal. Agent problem solving by using the domain network enables a concurrent execution of plan rules that are sequential in nature.

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Automated Design Method for Multi-domain Engineering Systems (멀티-도메인 공학시스템의 자동설계방법)

  • 서기성;박세현
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.6
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    • pp.1218-1227
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    • 2004
  • Multi-domain engineering systems include electrical, mechanical, hydraulic, pneumatic, and thermal components, making it difficult to design a system because of their complexity and inter domain nature. In order to obtain an optimal design, a unified design approach for each domain and an automated search method are required. This paper suggests a method for automatically synthesizing designs for multi-domain systems using the combination of bond graph that is domain independent and genetic programming that is well recognized as a powerful tool for open-ended search. To investigate the effect of proposed approach, an eigenvalue design problem is tested for some sample target sets of eigenvalues with different embryos.

A Time-Domain Approach for the Second-Order Diffraction Problem Around Circular Cylinders in Random Waves

  • YONGHWAN KIM
    • Journal of Ocean Engineering and Technology
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    • v.15 no.1
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    • pp.12-18
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    • 2001
  • This study concentrates on the second-order diffraction problem around circular cylinders in multi-frequency waves. The method of solution is a time-domain Rankine panel method which adopts a higher-order approximation for the velocity potential and wave elevation. In the present study, the multiple second-order quadratic transfer functions are extracted from the second-order time signal generated in random waves, and the comparison with other bench-mark test results shows a good agreement. This approach is directly applicable to prediction of nonlinear forces on offshore structures in random ocean.

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An Efficient Topology/Parameter Control in Evolutionary Design for Multi-domain Engineering Systems

  • Seo, Ki-Sung
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.2
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    • pp.108-113
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    • 2005
  • This paper suggests a control method for an efficient topology/parameter evolution in a bond graph-based GP design framework that automatically synthesizes designs for multi-domain, lumped parameter dynamic systems. We adopt a hierarchical breeding control mechanism with fitness-level-dependent differences to obtain better balancing of topology/parameter search - biased toward topological changes at low fitness levels, and toward parameter changes at high fitness levels. As a testbed for this approach in bond graph synthesis, an eigenvalue assignment problem, which is to find bond graph models exhibiting minimal distance errors from target sets of eigenvalues, was tested and showed improved performance for various sets of eigenvalues.