• 한국컴퓨터정보학회논문지
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• 제28권1호
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• pp.151-159
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• 2023

디지털 시대에 혁신은 정보기술발전의 핵심이다. 본문은 혁신 시스템 내 지역혁신능력의 차이를 새로운 관점에서 분석하고 있다. 본 연구는 커플링조정모델을 이용하여 중국의 31개 성, 시, 자치구의 혁신시스템(혁신투입, 혁신산출, 혁신환경)에 대해 커플링 정도를 비교 분석하고 있다. 분석 결과는 두 가지로 요약할 수 있다. 첫째, 중국의 전반적인 커플링 조정 수준은 낮다. 그리고 양호한 커플링과 높은 수준의 커플링 단계에 있는 지역의 수는 많지 않다. 둘째, 커플링의 전반적인 추세는 상승하고 있으나, 상대적으로 양호한 커플링 단계에 있는 지역은 대부분이 지역경제발전 수준이 높은 동부 연해안 지역에 분포되어 있다. 본문의 연구 결과는 혁신 능력 평가에 대한 새로운 관점을 제공할 수 있으며, ICT 산업의 발전을 촉진하는 데 혁신이 중요한 영향을 미칠 수 있음을 강조하고 있다.

• 한국지진공학회논문집
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• 제24권2호
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• pp.87-93
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• 2020

Seismic responses due to the dynamic coupling between a primary structure and secondary system connected to a structure are analyzed in this study. The seismic responses are compared based on dynamic coupling criteria and according to the error level in the natural frequency, with the recent criteria being reliant on the error level in the spectral displacement response. The acceleration responses and relative displacement responses of a primary structure and a secondary system for a coupled model and two different decoupled models of two degrees-of-freedom system are calculated by means of the time integration method. Errors in seismic responses of the uncoupled models are reduced with the recent criteria. As the natural frequency of the secondary system increases, error in the natural frequency decreases, but seismic responses of uncoupled models can be underestimated compared to that of coupled model. Results in this paper can help determine dynamic coupling and predict uncoupled models' response conservatism.

• 한국광학회지
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• 제15권1호
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• pp.28-33
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• 2004

상부 도파로와 중간 결합층이 적층된 단일모드 광섬유를 기본구조로 하는 측면 연마 광섬유 결합기를 상호 광 결합이 일어나는 영역을 다층막 도파로로 등가화하여 결합 효율을 해석하였다. 다층막 구조에서 중간 결합층의 유무에 따른 반사도를 계산하여 상부 도파로의 굴절률의 함수로 도시하였고, 상부 도파로의 굴절률이 광섬유 코어의 굴절률보다 클 경우 중간 결합층의 조건에 의해서 광 결합이 증가되어짐을 보였다. 리튬나오베이트를 상부 도파로로 가지는 결합기의 실험결과를 톤해 이론적 해석의 타당함을 보였고 계산 결과와 일치함을 보였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.309-313
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• 2000

A structural-acoustic coupling problem involving fluid in a cavity divided with flexible walls and porous materials is investigated in this paper. In many practical problems, the use of finite elements to discretize the fluid region leads to large stiffness and mass matrices. But, since the acoustic boundary element discretization requires to put elements only on the surface of structure, the size of matrices is reduced considerably. Here, we developed a numerical analysis program for the structural-acoustic coupling problems of the multi-region cavity, using boundary elements for the fluid regions and finite elements for the structure. By considering sound transmission through layered systems placed in a cavity, the accuracy of the coupled acoustical-structural finite element model has been verified by comparing its transmission loss predictions with analytical sloutions. Example problems are included to investigate the characteristics of the multi-region structural-acoustic coupling system with porous material.

• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.364-370
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• 2013

In the current paper, we propose a new modeling algorithm to analyze the coupling between an incident electromagnetic field (EMF) and a twisted conducting line, which is a kind of non-uniform line. Typically, analysis of external field coupling to a uniform transmission line (TL) is implemented by the Baum-Liu-Tesche (BLT) equation so that the induced load responses can be obtained. However, it is difficult to apply this method to the analysis of a twisted conducting line. To overcome this limitation, we used a chain matrix composed of ABCD parameters. The proposed algorithm expands the dimension of the previous chain matrix to consider the EMF coupling effectiveness of each twisted pair, which is then applied to multi-conductor transmission line (MTL) theory. In addition, we included a comparative study that involves the results of each method applied in the conventional BLT equation and new proposed algorithm in the uniform two-wire TL case to verify the proposed method.

• 한국안전학회지
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• 제18권2호
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• pp.119-124
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• 2003

Despite rapid technological advance and increased automation facilities, many jobs and activities in our living require manual materials handling(MMH). These include wide variety of activities such as moving things, lifting bags. boxes or cartons, etc. Many studies found that handle could affect on maximum acceptable weight of lifting, but there were few studies f3r the effects of work posture and coupling in lifting tote box. This study performed that ten male college students were required to lift a tote box with and without handle for three postures (bending, straight, right angle posture). From the experiment, following results were obtained. (1) MVC reduced maximum 23% by type of handle. (2) MVC was highest in straight posture, but was lowest in right angle posture. (3) As a result of ANOVA, MVC paid attention to posture and coupling. (p<0.01) (4) To all handle types, biceps brachii activity was increased in right angle posture. but reduced in straight posture. (5) To all posture, biceps brachii activity was most lively in no handle. The results of MVC measurement, subjective rating, EMG analysis, statistic analysis showed that maximum acceptable weight of lifting was influenced by type of handle and straight posture was more comfortable than other postures. Based on these results, it was concluded that acceptable weight of lifting has to differ for work posture and coupling.

• 전력전자학회논문지
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• 제24권2호
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• pp.78-83
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• 2019

In this study, we analyze the structure of the transceiver coil in the inductive power transfer (IPT) system. In the IPT system, the transceiver coil design needs to have the highest magnetic coupling possible because of the relatively low magnetic coupling due to the large gap of distance without the core. The transmitting coil may be formed as a multi-layer type according to the distance between the transmitting and receiving coils if the receiving coil is configured as a multi-layer type on the inner structure of the receiving apparatus, thereby improving the magnetic coupling and system efficiency. We compare and analyze the coil magnetic coupling, and system efficiency according to the layer structure of the transmitting and receiving coils and verify the analysis by JMAG simulation. Experimental results show that the layer structure of the transceiver should be considered according to the inner space of the receiving device and the spacing distance.

• 한국통신학회논문지
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• 제42권4호
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• pp.723-730
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• 2017

본 논문에서는 안테나 간의 상호 결합을 고려한 온라인 보상 알고리즘을 고려하였으며, 이를 적용하기 위한 새로운 GPS(Global Positioning System)용 안테나 배열을 제안하였다. 제안한 안테나 배열 및 ULA(Uniform Linear Array), URA(Uniform Rectangular Array)에 대한 항재밍 성능 평가를 위해 복수의 재밍신호 환경에 대한 방향탐지를 환경 조건 별로 나누어서 진행하였다. 1. 상호 결합이 존재하지 않는 환경. 2. 상호 결합이 있으나 보상이 이루어지지 않는 환경. 3. 상호 결합 보상이 이루어진 환경. RMSE(Root Mean Square Error) 분석을 통해 온라인 보상 알고리즘이 작동함을 확인하고 복수의 재밍신호에서도 피크 검출이 가능함을 보였다.

• 한국초전도ㆍ저온공학회논문지
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• 제11권3호
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• pp.1-5
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• 2009

It is important to predict AC loss in $Nb_3Sn$ and NbTi cable-in-conduit-conductor (CICC) reliably for the design and operation of large superconducting coils. The hysteresis loss in the superconducting filaments and coupling loss within strands and among strands in a cable or composite are dominant ac losses in superconducting magnets. The coupling loss in a superconductor can be characterized by identifying the coupling constant time $n{\tau}$. To reduce the coupling loss, all the strands (superconductor and Cu) in KSTAR (Korea Superconducting Tokamak Advance Research) are chromium plated with thickness of $l{\pm}0.5{\mu}m$. The ac losses of PF1, PF5 and PF6 coils has been measured by calorimetric method while applying trapezoidal current pulses with various ramp rate from 0.5 kA/s to 2 kA/s. The coupling time constants for $Nb_3Sn$ coils are $25{\sim}55$ ms and the values are not co-related with the coil size, the time constants for NbTi coil is 30 ms.

• Journal of Advanced Marine Engineering and Technology
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• 제38권3호
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• pp.262-268
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• 2014

본 연구는 2MW급 풍력 발전기용 고속커플링의 요구조건인 유연성과 절연성 및 과부하시 기능부품의 파손을 방지하기 위한 동력 차단기능을 만족하기 위한 구조설계와 검증에 관한 것이다. 커플링의 유연성과 절연기능은 강도와 유연성 및 절연성을 동시에 가지는 유리섬유강화플라스틱을 이용하여 설계하였으며 유한요소해석을 통하여 원소재 두께를 최적화하였다. 또한 이상 토크 발생시 동력전달을 차단하기 위한 토크리미터를 마찰차 형식으로 설계하였다. 시제품의 성능평가를 통하여 설계변수의 타당성을 검증하였다.