• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.785-790
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• 2011

This paper presents the effects of an assisting motor torque ripple on a driver's steering feeling using a simulink. The EPS(Electric Power Steering) System is modeled as a 5 degrees of freedom for simulation. To find out the influence of a torque ripple on a driver's steering feeling, which is the purpose of this study, we observed the assisting torque in various different speeds, when the torque ripple increased by 0%~40%. The torque ripple had a small but definite influence on the assisting torque, and it had a greater influence in low speeds rather than high speeds.

• 수산경영론집
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• 제50권3호
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• pp.73-86
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• 2019

The purpose of this study is to provide logical and policy justification for the feasibility and sustainability of the project through analysis of economic ripple effects of the fishing village new deal 300 project. To do this, we applied the industry-related analysis, which is mainly used to analyze the economic ripple effects, to the fishing village new deal 300 project. The industry association analysis classifies the detailed project of the preliminary plan for the selection of the business into the software business such as the hardware business and the capacity enhancement in the construction field and analyzes the economic ripple effect through the inter-industry association. As a result, it is expected that the fishing village new deal 300 project will have a positive economic impact. When the total investment of 3 trillion won is invested in the project, it is estimated that the production inducement effect and the value added effect are 5,545.3 billion won and 2,102.7 billion won, respectively. In addition, 62,005 get job inducements, where 10,952 employment inducements were associated with job creation. The analysis of the above impacts seems to have secured the logical justification for the implementation of the fishing village new deal 300 project.

• East Asian Economic Review
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• 제19권4호
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• pp.381-408
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• 2015

This paper investigates a link between the significant decline in the growth of domestic demand and the dampened ripple effects from the export sector in Korea since the East Asian financial crisis. The dampened ripple effects are closely linked to the changed investment behaviors of the Korean large-sized exporting firms since the crisis: they do not invest in their export earnings any more to create new industries; they tend to use more foreign value added contents for their exports and to increase outward direct investment by actively participating in global value chains. The paper also examines a link between the growth of domestic demand and the growth of household disposable income and presents reasons for the decline in the growth of household disposable income since the East Asian financial crisis.

• Journal of Magnetics
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• 제17권2호
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• pp.109-114
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• 2012

The torque characteristics of a surface-mounted permanent magnet synchronous motor (SPMSM) are analyzed in this study. The harmonics of the back electromotive force (EMF) and cogging torque are analyzed by the finite element method to study their effects on the torque ripple. Although low cogging torque can be achieved by varying geometric parameters such as the permanent magnet (PM) offset and notch depth on the stator teeth, the torque ripple is increased in some cases. The analysis results show that the ripple of the generated torque is determined by not only the amplitudes but also the phases of harmonics for the back EMF and cogging torque.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.347-349
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• 2013

This paper describes analysis and calculation of line frequency ripple current according to output capacitor value and effects of LED connection in the single stage flyback converter with high power factor. The low frequency output ripple current delivered from single stage converter has been analyzed in detail and the method evaluating parasitic resistance included in LED has been provided. In order to verify the equation derived in this paper, the single stage flyback converter has been designed with constant output current regulation with DCM operation. Experiments were conducted with different LED load structures to analyze the effect of LED parasitic resistance on output ripple current. As test results, the calculation can provide guide line to select capacitor values depending on output ripple current and LED characteristics.

• Journal of Information Science Theory and Practice
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• 제10권spc호
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• pp.66-75
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• 2022

The manufacturing industry is the foundation that drives economic growth, and manufacturing innovation is essential for sustainable growth advantage and the transition into a digital economy. Therefore, major countries actively support the field of simulations, which incorporate information and communication technologies into manufacturing, and announce various policies at the national level along with increasing investment. Simulation technology virtualizes product development processes to replace physical production and experimentation of products, dramatically reducing time and costs. In South Korea, the Korea Institute of Science and Technology Information (KISTI) has supported manufacturing companies for about 14 years by providing relevant technologies. This study uses the input-output table for the Bank of Korea to analyze the economic ripple effect. First, we identified the domestic industrial sector dealing with the supercomputing-based simulation industry. Then we analyzed its ripple effects by dividing them into the production inducement effect, value-added inducement effect, employment inducement effect, and forward/backward linkage effect. Consequently, when the supercomputing simulation budget of KISTI (28.3 billion won, 2007-2020) was set as an input coefficient, the analysis showed 45.1 billion won as the production inducement effect, 24.7 billion won as the value-added inducement effect, and 282 individuals per 1 billion won as the employment inducement effect. This study is significant in that it derived the effects of the inputs by analyzing the economic ripple effects of the projects of KISTI, which have been supporting South Korean manufacturing companies for the past 14 years with supercomputing-based simulations.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.902-906
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• 2008

The linear motors are easily affected by load disturbance, force ripple, friction, and parameter variations because there is no mechanical transmission to reduce the effects of model uncertainties and external disturbance. For highspeed/high-accuracy position control of a linear-motor-driven two axes, a nonlinear adaptive controller including a cross-coupling algorithm is designed in this paper. The nonlinear effects such as friction and force ripple are estimated and compensated. An enhanced approach for cross-coupling algorithm is proposed to effectively improve the biaxial contour accuracy with the closed-loop stability. The proposed controller is evaluated through the computer simulations.

• 대한기계학회논문집A
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• 제31권1호
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• pp.18-25
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• 2007

Linear motor is easily affected by load disturbance, force ripple, friction, and parameter variations because there is no mechanical transmission to reduce the effects of model uncertainties and external disturbance. These nonlinear effects have been reduced for high-speed/high-accuracy position control either through the better motor design or via the better control algorithm that can compensate the nonlinear effects. In this paper, a nonlinear adaptive control algorithm is designed and applied for the position control of permanent magnet linear synchronous motor. In order to estimate and compensate the nonlinear effects such as friction and force ripple, the estimation and the nonlinear adaptive control laws are derived based on the virtual control input and a suitable Lyapunov function. The proposed controller is evaluated through the computer simulations. The control algorithm is also implemented to a DSP board and interfaced to the PMLSM for verifying the realtime control performance.

• 통상정보연구
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• 제14권2호
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• pp.473-495
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• 2012

전자무역의 경제적 효과측면 따른 다양한 비용절감 효과와 영향요인을 바탕으로 한 무역거래는 신속한 수출입 통관을 통해 시장변화에 능동적으로 대응할 수 있는 기반제공에 따른 무역업체의 비용절감과 경영효율화를 통한 대외경쟁력제고 및 이미지제고와 더불어 기업내 실시간 정보공유를 통해 고객에 대한 서비스를 제공하는 유 무형의 효과를 발휘하고 있다는 것을 시사점으로 전자무역의 활성화가에 필요한 이유이다. 이러한 배경을 바탕으로 글로벌 무역체계를 구축하기 위한 전자무역 플랫폼을 구축에 의한 무역거래 업무를 실행함으로써 과거 전통적인 무역거래에서 이루어진 패러다임의 변화와 새로운 장치마련에 따른 무역거래관련 문서와 비용 측면에서 경제적인 효과를 극대화하기 위한 방안으로 전자무역 실행에 따른 파급효과에 대한 내용을 바탕으로 향후 대응방안을 제시하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.685-688
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• 1992

This paper studies the commutation phenomenon in the Brushless DC Motor with the trapezoidal BEMF waveform. It is shown that the torque ripple am the speed ripple due to the phase commutation depend on driving sytem, operating speed am load condition. The effects of resistance and BEMF flat width on torque ripple are considered. Speed - torque characteristics of the motor is presented considering the phase commutation. Uncommutating current control method can attenuate the torque ripple in the low speed region, and also minimize the switching loss am switching frequency. In this paper, the commutation phenomena are verified by analytical formulation and simulation.