• Title/Summary/Keyword: Degree of Coupling

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An Evaluation of the Coupling Coordination Degree of the Yangtze River Delta Port Cluster Based on Coupling Theory

  • Lu Ke;Yong-Sik Oh
    • Journal of Navigation and Port Research
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    • v.48 no.2
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    • pp.78-87
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    • 2024
  • To quantitatively assess the correlation between subsystems within a port cluster and the overall coordinated development of the port group, the current paper evaluates the coordinated development of port clusters. First, we construct an evaluation index system for the coupling and coordination of port clusters. Next, we introduce the contribution index of port subsystems, coupling degree, and coupling coordination degree functions to formulate a coupling coordination evaluation model for the port cluster. Finally, we use the Yangtze River Delta port cluster as a case study for validation, specifically using empirical data from 2012 to 2021. The findings reveal distinct phased characteristics in the coupling and coordination of port clusters in the Yangtze River Delta, marked by a notable transition from "maladjustment" to "coordination." Further, sustained high coupling values over a decade indicate a significant level of competition and cooperation among ports within the Yangtze River Delta port cluster. Over time, this competitive and collaborative dynamic has progressively evolved toward a more positive and structured direction. Lastly, it is expected that the evaluation model proposed in this paper can be extrapolated to other port clusters to gauge the extent of coordinated development, thereby facilitating horizontal comparisons and vertical analyses.

The Study on Degree of Coupling in Coupled Shear Wall System (병렬 전단벽의 커플링 정도에 관한 연구)

  • Park Wan-Shin;Yoon Hyun-Do;Hwang Sun-Kyung;Kim Sun-Woo;Han Min-Ki;Lee Won-Suk
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.135-138
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    • 2005
  • Since a ductile coupled shear wall system is the primary seismic load resisting systems of many structures, a coupling beams of these system must exhibit excellent ductility and energy absorption capacity. In this paper, the seismic response of coupled shear wall system is discussed. It includes that the evaluation of the degree of coupling between the shear walls and the coupling beams. It is demonstrated through a review of experimental investigations of coupling beam behavior that often the coupling beam ductility demand exceeds the expected available ductility. As a result, it is possible that coupled shear wall system will not behave as desired in the course of a significant seismic event. Limits to the allowable degree of coupling are proposed as a remedy to this apparent deficiency.

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Research on the Coupling Coordination Relationship between Regional Information Technology Level and Economic Development

  • Li, Jin-yang;kim, Hyung-Ho;Yang, Jun-Won
    • International journal of advanced smart convergence
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    • v.11 no.2
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    • pp.153-162
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    • 2022
  • The impact of the information technology industry on economic development is becoming increasingly important. In this study, we take China's provincial-level regions from 2015 to 2020 as the research object, comprehensively evaluates the level of their information technology systems by the entropy weight method, and then measures the coupling coordination relationship between the information technology system and the economic development system by the coupling coordination degree model. As a result, we found that the income of the information technology industry, the investment of talents and science research have the most important influence on the level of the information technology system. During the research period, with increasing values, the coupling degree of the two systems was at a high level. Affected by development strategies, diffusion effects and industrial relocation, the coupling degree in the central and western regions has shown a rapid growth trend. The coordination degree of the two systems is relatively low, and 83.9% of the provinces are in the medium-low coordination stage. The information technology industry has obviously promoted economic development. Besides, relevant policies should be introduced to effectively support and guide the high-quality development of the information technology industry and promote the high-level coordinated development of the two systems.

Mathematical Model of Two-Degree-of-Freedom Direct Drive Induction Motor Considering Coupling Effect

  • Si, Jikai;Xie, Lujia;Han, Junbo;Feng, Haichao;Cao, Wenping;Hu, Yihua
    • Journal of Electrical Engineering and Technology
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    • v.12 no.3
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    • pp.1227-1234
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    • 2017
  • The two-degree-of-freedom direct drive induction motor, which is capable of linear, rotary and helical motion, has a wide application in special industry such as industrial robot arms. It is inevitable that the linear motion and rotary motion generate coupling effect on each other on account of the high integration. The analysis of this effect has great significance in the research of two-degree-of-freedom motors, which is also crucial to realize precision control of them. The coupling factor considering the coupling effect is proposed and addressed by 3D finite element method. Then the corrected mathematical model is presented by importing the coupling factor. The results from it are verified by 3D finite element model and prototype test, which validates the corrected mathematical model.

Analysis on the Measured Natural Frequencies Due to the Structure-Exciter Interaction (구조물-가진기 상호작용에 의한 공진주파수 변동에 대한 해석)

  • Han, Sang-Bo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.7
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    • pp.2108-2117
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    • 1996
  • The purpose of this paper is to investigate the influence of the exciter attached for the measurement of natural frequencies when extracting the frequency response functions of the test structure in experimental modal analysis. The procedure is first to model the attached exciter as an additional degree of freedom system and next to verify the suggested model by experimentally extracting the natural frequencies of the test structure with various values of exciter mass, stinger stiffness and attachment position of the exciter on the test structure. It is concluded that as additional degree of freedom system which includes the natural frequency of the exciter itself and axial stiffness of stinger should be considered to quantatively define the coupling effects of structure-exciter interaction on the measured natural frequencies. It is not the mass of the exciter itself but the coupling effect of the additional degree of freedom mass-spring system consisting of exciter body and armature coil that characterizes the natural frequency deviation. Therefore, when the natural frequency of this additional mass-spring system is outside of the test frequency range, the coupling effect of structure-exciter interaction can be minimized.

The Coupling Analysis of Innovation Input-Innovation Output-Innovation Environment-The Case of China

  • Hang, Li;Sangwook, Kim
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.1
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    • pp.151-159
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    • 2023
  • In the digital age, innovation is at the heart of information technology development. This paper explores the differences of regional innovation capabilities from within the innovation system from a new perspective. By applying the coupling coordination degree model, the coupling coordination degree analysis is conducted for the three systems of innovation (innovation input, innovation output, and innovation environment) in 31 provinces, municipalities, and autonomous regions of China. The results show that: the overall level of coupling coordination degree in China is low, and the number of provinces in good coordination and quality coordination is low number, but they are all distributed in the eastern economically developed regions, showing a high correlation between regional innovation and regional economic development. The overall trend of China's innovation coordination is on the rise. The research results of this paper can provide a new perspective for the evaluation of innovation capability, and also provide an important impact of innovation on promoting the development of ICT industry.

Analysis of Coupling Between Digital Noise and Portable Smart Terminal Antenna According to Antenna Types (휴대용 스마트 단말기 안테나 타입에 따른 디지털 노이즈와 안테나의 결합 분석)

  • Kim, Joonchul
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.873-877
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    • 2019
  • In this paper, we analyze the degree of digital noise coupling for Inverted F Antenna (IFA) and Loop Antenna, which are representative types of portable terminal antenna, using characteristic mode. Firstly, the degree of coupling according to the direction of digital signal lines and characteristic mode current of the printed circuit board (PCB) including the antenna is compared and analyzed, and based on this result, the coupling between WiFi antenna and the front camera noise is analyzed. For analysis, the digital signal line and ground line of the FPCB of the camera module are modeled as a loop feeder that excites the characteristic mode of the PCB ground and the change of noise coupling according to the antenna types are analyzed.

Experiment and analysis of dynamic coupling phenomenon in a seat (시트에서 발생하는 동적 커플링 현상 실험 및 분석)

  • Min, Kyongwon;Kim, Deokman;Park, Hyunkyu;Park, Junhong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.1004-1006
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    • 2014
  • This study was conducted to improve the understanding of factors affecting an automobile seat cushion in dynamic conditions. When there are two dummies on the seat to measure each places respectively at once, the shape of the transfer function changes because the dummies affect each other as if they are linked with some kind of a spring when under excitation. A simple two-degree-of-freedom linear model is used to define a translational stiffness of dynamic coupling phenomenon. The cushion deflection model was created to find the relation between dynamic coupling and distance. Experimental set-up was made to compare with the two-degree-of-freedom linear model. The dynamic coupling factor could be utilized to improve the dynamic comfort of automobile seats.

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A Mathematical Formulation of the Structural-acoustic System with an Opening and a Flexible Structure (입구와 유연한 구조물로 구성된 경계를 가지는 구조-음향 연성계의 수학적 표현)

  • Seo, Hee-Seon;Kim, Yang-Hann
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.5 s.98
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    • pp.527-535
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    • 2005
  • This paper explains a general coupling system in terms of the system parameters. impedance of a cavity or mobility of a structure. To easily access the mechanism of the structural-acoustic coupled system, a simple expression is derived. A general coupled equation is also derived of a general coupled problem constituted a flexible structure and an opening boundary in terms of vector and matrix notation, and is analyzed the coupling phenomena using the understanding acquired simple coupled system. The paper shows that the general coupled equation is expanded version of the simple coupled equation by some limiting checks. The paper also shows that the degree of coupling is proportioned to a stiffness of the acoustic system and a modal coupling coefficient, but is in inverse proportion to a mass of the structural system and the difference of the excitation frequency and resonant frequency of the acoustic or structural system.