• Title/Summary/Keyword: global coupling

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Coupling Particles Swarm Optimization for Multimodal Electromagnetic Problems

  • Pham, Minh-Trien;Song, Min-Ho;Koh, Chang-Seop
    • Journal of Electrical Engineering and Technology
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    • v.5 no.3
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    • pp.423-430
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    • 2010
  • Particle swarm optimization (PSO) algorithm is designed to find a single global optimal point. However, the PSO needs to be modified in order to find multiple optimal points of a multimodal function. These modifications usually divide a swarm of particles into multiple subswarms; in turn, these subswarms try to find their own optimal point, resulting in multiple optimal points. In this work, we present a new PSO algorithm, called coupling PSO to find multiple optimal points of a multimodal function based on coupling particles. In the coupling PSO, each main particle may generate a new particle to form a couple, after which the couple searches its own optimal point using non-stop-moving PSO algorithm. We tested the suggested algorithm and other ones, such as clustering PSO and niche PSO, over three analytic functions. The coupling PSO algorithm was also applied to solve a significant benchmark problem, the TEAM workshop problem 22.

Nonlinear modeling parameters of RC coupling beams in a coupled wall system

  • Gwon, Seongwoo;Shin, Myoungsu;Pimentel, Benjamin;Lee, Deokjung
    • Earthquakes and Structures
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    • v.7 no.5
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    • pp.817-842
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    • 2014
  • ASCE/SEI 41-13 provides modeling parameters and numerical acceptance criteria for various types of members that are useful for evaluating the seismic performance of reinforced concrete (RC) building structures. To accurately evaluate the global performance of a coupled wall system, it is crucial to first properly define the component behaviors (i.e., force-displacement relationships of shear walls and coupling beams). However, only a few studies have investigated on the modeling of RC coupling beams subjected to earthquake loading to date. The main objective of this study is to assess the reliability of ASCE 41-13 modeling parameters specified for RC coupling beams with various design details, based on a database compiling almost all coupling beam tests available worldwide. Several recently developed coupling beam models are also reviewed. Finally, a rational method is proposed for determining the chord yield rotation of RC coupling beams.

Mutual Coupling Compensation and Direction Finding for Anti-Jamming 3D GPS Antenna Array (항재밍 3차원 GPS 배열 안테나를 위한 Mutual coupling 보상 및 재밍 방향탐지 알고리즘)

  • Kang, Kyusic;Sin, Cheonsig;Kim, Sunwoo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.42 no.4
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    • pp.723-730
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    • 2017
  • In this paper, we consider an online compensation algorithm considering the mutual coupling and suggest a new GPS antenna array to apply. To evaluate the anti-jamming performance for the proposed antenna array, ULA and URA, we divide direction finding of multiple jamming signals into environments. 1. there is no mutual coupling. 2. there is mutual coupling but no compensation. 3. mutual coupling is compensated. RMSE analysis showed that the online compensation algorithm works and that peak detection is possible for multiple jamming signals.

A Situation Simulation Method for Achieving Situation Variability and Authoring Scalability based on Dynamic Event Coupling

  • Choi, Jun Seong;Park, Jong Hee
    • International Journal of Contents
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    • v.16 no.1
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    • pp.25-33
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    • 2020
  • We develop a simulation method that affords very high variability of virtual pedagogical situations involving many independent plans, still achieves authoring (or implementation) scalability. While each individual plan would be coherently drawn up by an agent for its respective goal, those independently-made plans might be coincidentally intertwined in their execution. The inevitable non-determinism involved in this multi-event plan encompassing pre-planned and unforeseen events is resolved by (multi-phase) dynamic planning and articulated sequencing of events in contrast to static planning and monolithic authoring in conventional narrative systems. Connections between events are dictated by their associated rules and their actual connections are dynamically determined in execution time by current conditions of background-world. This unified connection scheme across pre-planned and unforeseen events allows a multi-plan, multi-agent situation to be coherently planned and executed in a global scale. To further the variability of a situation, the inter-event coupling is made in a fine level of action along with a limited episteme of each agent involved. We confirm analytically the viability of our approach with respect to the situation variability and authoring scalability, and demonstrate its practicality with an implementation of a composite situation.

Synthesis of 3,4,5-Trisubstituted Isoxazoles through Gold-Catalyzed Cascade Cyclization-Oxidative Alkynylation and Cyclization-Fluorination of 2-Alkynone O-Methyloximes

  • Song, Doo-Hee;Ryu, Jae-Sang
    • Bulletin of the Korean Chemical Society
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    • v.35 no.9
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    • pp.2635-2644
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    • 2014
  • Gold-catalyzed tandem cyclization-oxidative alkynylation and cyclization-fluorination reactions of 2-alkynone O-methyloximes are described. The reactions proceed smoothly at room temperature in the presence of 10 mol % of $(PPh_3)AuNTf_2$, 2.5 equivalents of selectfluor, and 2 equivalents of $K_3PO_4$. 2-Alkynone O-methyloximes undergo intramolecular oxyauration/cyclization and ensuing oxidative cross-coupling and fluorination process to afford the corresponding 3,4,5-trisubstituted isoxazoles in a cascade manner.

Development of high-precision 2-axis translation system comprised of microstage and global stage (Microstage와 global stage를 결합한 초정밀 2축 이동장치 개발)

  • 김종윤;엄태봉
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.311-314
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    • 1997
  • According to the development of industrial equipment such as semiconductor manufacturing machines, optical device, and precision machine tool, a high-precision translation system with wide range has been required. This paper describes a high-precision 2-axis translation system, which consists of microstage and global stage. In order to achieve the highresolution in the long range, some engineering techniques are used. Three linear guides with flexible coupling are adopted to reduce the motor vibration in the global stage. A simple elastic hinge structure activated by five PZT is applied to reduce the angular dev~atlon. As the result of combination of microstage and global stage associated with some engineering techniques, the 2-axis translation system can measure the 200 X 200 mrn range with the nanometer accuracy.

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Global Production Network and Coupling Strategy of IT Industrial Clusters in Dongguan, China (중국 동관 IT 산업 클러스터의 글로벌 생산 네트워크 및 커플링 전략)

  • Lee, Sang-Bin;Sung, Eul-Hyun;Yeom, Myung-Bae
    • Journal of the Korea Convergence Society
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    • v.8 no.7
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    • pp.39-46
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    • 2017
  • Dongguan City of Guangdong province, one of the core areas of the Pearl River Delta, has also pursued economic development through the geographical advantage close to Hong Kong. In the early 1980s, small and medium-sized multinational corporations related to home appliances industry from Hong Kong invested to the Dongguan area and set up a production factory. In the mid-1990s, as Taiwanese PC manufacturers invested, local industrial clusters have developed in Dongguan with core of the IT, PC components and electronic industries. The case of the IT industrial cluster in Dongguan is a typical example of the development of Chinese manufacturing industry after the reform of China. This paper focused on the coupling strategy case of Dongguan City industrial cluster in Guangdong province, and theoretically compared the endogenous growth factor analysis(NMID) of regional industrial development with the regional differentiation of industry based on external linkage with global production network(GPN).

Accuracy of Short-Term Ocean Prediction and the Effect of Atmosphere-Ocean Coupling on KMA Global Seasonal Forecast System (GloSea5) During the Development of Ocean Stratification (기상청 계절예측시스템(GloSea5)의 해양성층 강화시기 단기 해양예측 정확도 및 대기-해양 접합효과)

  • Jeong, Yeong Yun;Moon, Il-Ju;Chang, Pil-Hun
    • Atmosphere
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    • v.26 no.4
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    • pp.599-615
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    • 2016
  • This study investigates the accuracy of short-term ocean predictions during the development of ocean stratification for the Korea Meteorological Administration (KMA) Global Seasonal Forecast System version 5 (GloSea5) as well as the effect of atmosphere-ocean coupling on the predictions through a series of sensitive numerical experiments. Model performance is evaluated using the marine meteorological buoys at seas around the Korean peninsular (KP), Tropical Atmosphere Ocean project (TAO) buoys over the tropical Pacific ocean, and ARGO floats data over the western North Pacific for boreal winter (February) and spring (May). Sensitive experiments are conducted using an ocean-atmosphere coupled model (i.e., GloSea5) and an uncoupled ocean model (Nucleus for European Modelling of the Ocean, NEMO) and their results are compared. The verification results revealed an overall good performance for the SST predictions over the tropical Pacific ocean and near the Korean marginal seas, in which the Root Mean Square Errors (RMSE) were $0.31{\sim}0.45^{\circ}C$ and $0.74{\sim}1.11^{\circ}C$ respectively, except oceanic front regions with large spatial and temporal SST variations (the maximum error reached up to $3^{\circ}C$). The sensitive numerical experiments showed that GloSea5 outperformed NEMO over the tropical Pacific in terms of bias and RMSE analysis, while NEMO outperformed GloSea5 near the KP regions. These results suggest that the atmosphere-ocean coupling substantially influences the short-term ocean forecast over the tropical Pacific, while other factors such as atmospheric forcing and the accuracy of simulated local current are more important than the coupling effect for the KP regions being far from tropics during the development of ocean stratification.

Behavior, Design, and Modeling of Structural Walls and Coupling Beams - Lessons from Recent Laboratory Tests and Earthquakes

  • Wallace, John W.
    • International Journal of Concrete Structures and Materials
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    • v.6 no.1
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    • pp.3-18
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    • 2012
  • Observed wall damage in recent earthquakes in Chile and New Zealand, where modern building codes exist, exceeded expectations. In these earthquakes, structural wall damage included boundary crushing, reinforcement fracture, and global wall buckling. Recent laboratory tests also have demonstrated inadequate performance in some cases, indicating a need to review code provisions, identify shortcomings and make necessary revisions. Current modeling approaches used for slender structural walls adequately capture nonlinear flexural behavior; however, strength loss due to buckling of reinforcement and nonlinear and shear-flexure interaction are not adequately captured. Additional research is needed to address these issues. Recent tests of reinforced concrete coupling beams indicate that diagonally-reinforced beams detailed according to ACI 318-$11^1$ can sustain plastic rotations of about 6% prior to significant strength loss and that relatively simple modeling approaches in commercially available computer programs are capable of capturing the observed responses. Tests of conventionally-reinforced beams indicate less energy dissipation capacity and strength loss at approximately 4% rotation.

A variationally coupled Element-Free Galerkin Method(EFGM) -Boundary Element Method(BEM) (무요소법과 경계요소법의 변분적 조합)

  • 이상호;김명원
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.10a
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    • pp.11-18
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    • 2001
  • In this paper, a new algorithm of coupling Element-Free Galerkin Method(EFGM) and Boundary Element Method(BEM) using the variational formulation is presented. A global variational coupling formulation of EFGM-BEM is achieved by combining the variational form on each subregion. In the formulation, Lagrange multiplier method is introduced to satisfy the compatibility conditions between EFGM subregion and BEM subregion. Some numerical examples are studied to verify accuracy and efficiency of the proposed method, in which numerical performance of the method is compared with that of conventional method such as EFGM-BEM direct coupling method, EFGM and BEM. The proposed method incorporating the merits of EFGM and BEM is expected to be applied to special engineering problems such as the crack propogation problems in very large domain, and underground structures with joints.

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