• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.67-76
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• 2006

This paper describes the analysis method to define the system specification for conducted EMI environment and verification method to evaluate the conducted EMI performance. Conducted EMI environment is characterized by the electrical power subsystem which is mainly issued by the switching circuit noise, common ground impedance coupling. To define and control these EMI problems, EMI assesment through system analysis are preceded at the early design phase and then EMI reduction methods are applied during the unit/system development phase. System EMC should be carefully controlled and designed in the consideration of EMC safety margin and its performance is fully evaluated at the whole development period.

• Journal of Convergence for Information Technology
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• v.11 no.5
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• pp.57-65
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• 2021

Purpose: To analyze students' attitudes toward English-Medium Instruction (EMI) classes for nursing students. Methods: From January 23 to January 30, 2020, a survey was conducted using a web-based survey program on student attitudes, satisfaction, and improvement measures for EMI classes. 216 responded to the survey, giving a response rate of 63.7%. Results: The item with the highest score on the attitude toward EMI lectures was 'EMI classes will be of great help to student's future'. The item 'I will try to speak English with my classmates outside of the EMI class if possible' showed the lowest score. Students answered that they need an appropriate educational environment for the smooth operation of EMI classes, fewer students per class and support for group studies

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.1-7
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• 2008

This paper presents electromagnetic interference(EMI) suppression method applied on the direct current(DC) motor driver for power tail gate control. EMI noise is generated by the fast switching of power devices connected to electric loads. It has become a matter of concern because of the vast increase in the number and sophistication of electronic system in automotive environment. The proposed EMI reduction method is based on the principle of reducing the transient speed of power devices by changing the parameters of the driver circuit related to the power MOSFET. In this paper, power losses were calculated by loss equations and thermal simulation was used to evaluate the effect on printed circuit board. Based on these results, the DC motor driver was fabricated and tested. The proposed method can help to design a DC motor driver which allows it to obtain an acceptable compromise between power losses and EMI.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.916-924
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• 2015

Electromagnetic Interference (EMI) is a system to system or environment to system phenomenon. The literature survey proved that the Randomized Pulse Width Modulation (RPWM) technique is a promising technique to reduce EMI. A new Constant Trailing Edge, Randomized Pulse Width Modulation (CTERPWM) technique is proposed in this paper. The effect of the proposed RPWM technique for mitigation of conducted-EMI on Cuk converter operating in Continuous Conduction Mode (CCM) is simulated and tested. In this paper, the analytical expressions for the Power Spectral Density (PSD) are derived for the proposed RPWM technique and are validated by experimental measurements. The effectiveness of the proposed RPWM technique on the mitigation of conducted-EMI is verified comparing simulation and experimental results and it is identified that both the results are almost similar with allowable experimental deviations. The comparative investigation proves that the proposed RPWM technique can mitigate and spread the dominant peaks of conducted-EMI over the complete spectrum for the Cuk converter. Based on the investigation the CTERPWM technique is recommended for adoption.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.4
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• pp.471-477
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• 2014

In this paper, a modeling and co-simulation methodology is proposed to predict the radiated electromagnetic interference (EMI) from on-chip switching I/O buffers. The output waveforms of I/O buffers are simulated including the on-chip I/O buffer circuit and the RC extracted on-chip interconnect netlist, package, and printed circuit board (PCB). In order to accurately estimate the EMI, a full-wave 3D simulation is performed including the measurement environment. The simulation results are compared with near-field electromagnetic scan results and far-field measurements from an anechoic chamber, and the sources of emission peaks were analyzed. For accurate far-field EMI simulation, PCB power trace models considering IC switching current paths and external power cable models must be considered for accurate EMI prediction. With the proposed EMI simulation model and flow, the electromagnetic compatibility can be tested even before the IC is fabricated.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.184-184
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• 2005

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.341-342
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• 2006

A physical model for reduction of Electromagnetic Interference(EMI) or its predecessors, Radio Noise, Electrical Noise, or Radio-Frequency-Interference(RFI), is a rapidly expanding digital technology. It covers the frequency spectrum from DC to about 3 GHz EMI is the poisoner which does not allow radio, TV, radar, navigation, and a lot of electrical, electro-mechanical, and electronic and communication devices, apparatus and systems to operate compatibly in a common frequency spectrum environment EMI can result in a jammed radio, heart pacer failures, navigation errors and many other either nuisance or catastrophic events. Therefore, it follows that this spectrum pollution problem has reached international levels of concern and must be dealt with m proportion to the safety and economic impact Involved.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.6 s.121
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• pp.612-619
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• 2007

In this paper, a Four-wired antenna was designed and manufactured using Four-wires in order to perform EMI/EMC experiments. As compared with a TEM cell, the feature of the Four-wired antenna has simple installment with broadband balun, a Four-wired antenna, and loading resistances in an anechoic chamber. And the E-field polarization of antenna can be easily changed. Without the limitation of space, EMI/EMC experimental environment could be built within the anechoic chamber with the moderate cost. In S, C, and X-bands, the manufactured antenna was able to make an experiment on EMI/EMC with the DUT which has the quiet zone of the height, width, length equal to about 10 cm.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.444-451
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• 2019

In this paper, we introduce the design consideration of the EMI and lightning induced transient protection circuit for RS-170a video signal on the avionics equipment. Avionics equipment is subject to the risk of malfunction or physical damage due to indirect lightning effect from lightning strike or electromagnetic interference from external environment. So in order to protect the avionics equipment from these effects, we should analyze the effect of electromagnetic interference and lightning strike on aircraft and apply protection design for each avionics device, but protection circuit may cause signal distortion if signal level is low and frequency is high. In this paper, we introduce common protection design for EMI and indirect lightning effect, and consideration for minimize signal distortion caused by protection circuit for RS-170a. In addition, we show some example of improvements to the actual equipment design using consideration discussed in this paper.

• Cross-Cultural Studies
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• v.53
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• pp.251-277
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• 2018

The purpose of this study was to investigate ways to improve the effect of English-medium instruction (EMI) in Korean universities by comparing EMI lectures in two Korean universities with those in a Japanese university. Some universities run all courses in English while others do so for only part of them. This study comparatively investigated how EMI courses were run by these two groups of universities. For the purpose of this study, in-depth interviews were conducted with EMI instructors and students to find out what merits and problems that such EMI programs had in EFL environment of Korea and Japan. Another important goal was to correct problems and improve the Korean programs. The result showed that the most important issue of EMI programs in Korean universities was students' low English proficiency. It also demonstrated that English for Academic Purposes (EAP) was necessary to overcome this problem. It is a key to the success of MI programs. Hopefully, this study will stimulate continuous discussions on limitations and ways to improve EMI in Korean universities in various aspects.