• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.470-474
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• 2006

In the case of dryer tendency that select directly without being serviced with salesperson's opinion specially because it does Purchase with sufficient knowledge is package of goods being high and labeling for goods of consumers are indicated to very important element This development wishes to escape and use "Seramik heater" and apply electromagnetic waves cover skill to be Hair Drier that head of a family electromagnetic waves are happened in method and household electric appliance that can raise sexual intercourse of circle infrared rays and High efficiency quantity of heat and coincide in high efficiency and All function anger request in existent metal heat ray.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.624-627
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• 2000

The shielding effectiveness of materials is determined by measuring the ratio of the incident electromagnetic power which passes through the material under test. To measure the shielding effectiveness materials made by conductive polymer, the flanged coaxial transmission-line holder based in ASTM D4935-89, was fabricated. This apparatus has dynamic range between 95dB and 120dB in frequency range of 50Mhz-2Ghz. Furthermore, this system can be utilized to measure the shielding effectiveness of materials produced by conductive polymer and can be adapted for shielding materials design.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.836-845
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• 1998

In this ppaer, the confguration of multi-layers of the image planes surrounding the current trace of inite width has been considered, and the shielding performance of image planes is analyzed with the parameters of the width and conductivity of the planes, and the distance between the current trace and the planes. The induced current distributions on the image planes have bgeen calculated by solving a set of electric field integral equations by the method of moments. To cacluate the current distribution on the planes effectively, a new method for dividing integral intervals is proposed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.1
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• pp.61-68
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• 2017

In this paper, we propose an improved magnetic field shielding structure to reducing the magnetic field generated in the wireless power transfer system operating at a low frequency band. The proposed structure consists of the magnetic material and the conductive material, magnetic field cancelling effect for power transfer is minimized while improving the leakage magnetic field cancelling effect by optimizing the various design parameters in the proposed structure. We analyzed and verified the efficiency of the wireless power transfer system and the reduction effect of the leakage magnetic field through computer simulation and measurement. Analysis results show that power transfer efficiency of the wireless power transfer system utilizing the proposed structure is 77 %, which is maintained at the conventional power transfer efficiency. In addition, compared with the structure maintaining high power transfer efficiency, leakage magnetic field strength is reduced to 29~37 % at the nearest point.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.1 s.139
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• pp.149-156
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• 2005

The purpose of this study was to produce the high quality of electromagnetic wave shielding fabrics. In this study, we have produced polyester fabrics by electroless Ag plating. The untreated polyester was etched with $4\%$ NaOH solution added accelerant(Benzyl Dimethyl Dodecyl Ammonium Chloride) then it was catalyzed by $SnCl_2$ solution and activated by $PdCl_2$ solution. Electroless Ag plating was carried out by changing conditions such as temperature. time, weight loss rate of polyester and kind of reducing agents. The electromagnetic wave shielding effectiveness of polyester fabric by electroless Ag plating was measured by RF Impedance Analyzer and element of electromagnetic wave shielding substance was measured using Electron probe micro analyzer. The results were as follows; The plating bath using potassium sodium tartrate by reducing agent was excellent electromagnetic wave shielding effectiveness. Element of electromagnetic wave shielding substance was silver. Electromagnetic wave shielding effectiveness was shown over 64dB at the temperature of $40^{\circ}C$, treating time 30min., weight loss rate $20\%$.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.608-611
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• 2004

As the use of various electronic equipments has been increased recently according to industrialization and information network establishment, concern about electromagnetic wave exposed environment has also been increased. Therefore, this study aims to verify electromagnetic wave absorbing effects of inorganic paint that is made of carbon, electro-conductive materials with regard to its physical characteristics, its electromagnetic wave absorbing rate through a mock-up test for proving its effects in the indoor condition. The results are as follows: The results of running tests on electromagnetic wave absorbing inorganic paints for checking their requirements as painting material such as adherence degree, resistance to fine crack, resistance to washing, alkali-resistance, discoloration-resistance, etc. show that inorganic paints have the physical characteristics meeting the requirements for painting materials. In addition, it shows that the electromagnetic wave absorbing effect, in line with the number of paintings and the thickness of paintings, secures $75\~89\%$ of efficiency. And the mock-up test shows that the electromagnetic wave absorbing effect inside building is directly proportional to the distance from the source of electromagnetic wave such as electronic equipments.

• Journal of Aerospace System Engineering
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• v.17 no.1
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• pp.68-78
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• 2023

In this paper, improvement measures were studied for false alarm (abnormal lighting) of emergency hydraulic warning light due to RF radiation signals in aircraft. When the warning lamp of the emergency hydraulic system is lit during flight due to electromagnetic interference caused by RF radiation signals, it affects flight mission and safety which can result in efficiency degradation and maintenance of flight mission. For false alarm of emergency hydraulic warning light, root cause analysis and troubleshooting were carried out. By shielding a composite strip under fuselage of the aircraft located in the path of the RF radiation signal, the RF radiation signal flowing into the emergency hydraulic indicator was blocked. Results of applying the improvement method through ground and flight monitoring were also described.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.345.1-345.1
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• 2016

구리 피막은 열 및 전기를 잘 전달하는 특성으로 인해 전기 배선이나 Heat Sink 재료 등에 이용되고 있다. 최근에는 전자파 차폐나 FCCL (Flexible Copper Clad Laminate) 등의 피막으로 널리 이용되면서 연속 코팅 및 후막 제조를 위한 고속 소스의 필요성이 증가하고 있다. 연속코팅 설비에 적용하거나 후막을 경제적으로 제조하기 위해서는 정지상태의 기판을 기준으로 시간당 $100{\mu}m$ 이상의 증착 속도가 요구된다. 기존 마그네트론 스퍼터링 소스의 경우 일반적으로 증착율이 시간당 $20{\mu}m$ 이내이며, 고전력을 이용하는 소스의 경우도 $60{\mu}m$를 넘지 못하고 있다. 본 발표에서는 자기장 시뮬레이션을 통해 자석의 배열을 최적화하고 냉각 효율을 고려한 소스 설계를 통해 고속 스퍼터링 소스를 제작하고 그 특성을 평가하였다. 제작된 소스는 구리 코팅을 위한 스퍼터링 공정 조건을 도출하고 다양한 기판에 $20{\mu}m$ 이상의 구리 후막을 코팅하여 미소 형상 및 코팅 조직을 분석하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.12
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• pp.933-940
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• 2017

A wireless power transfer system with a negative impedance converter(NIC) was designed and tested. The system was investigated to identify the effects of ferrites and conductors. To improve the power transfer efficiency(PTE), the Q-factor of the transmitter was enhanced by the negative resistance generated by the NIC. The NIC was composed of an Op-Amp and resistors. The negative resistance was obtained with respect to a resistor connected in a feedback loop. The dimension of the Tx coil was $250mm{\times}250mm{\times}0.8mm$. The impedance and Q-factor were $31+j1874{\Omega}$ and 60, respectively. The negative resistance was selected to be $30{\Omega}$, and the Q-factor was increased to 900 by reduction of the transmitter resistance, which was about 15 times higher than that of a conventional transmitter. The measured PTE was greatly improved in comparison to that of a conventional system. These results demonstrate that the PTE is enhanced by using the NIC.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.10
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• pp.59-67
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• 2020

Polycarbonate thermoplastic composite materials are anisotropic and exhibit physical properties in the longitudinal direction. Therefore, the physical properties depend on the type and direction of reinforcements. The thermal conductivity, electrical conductivity, and resin impregnation can be controlled by adding carbon nanotubes to polycarbonate resin. However, the carbon fiber used as a reinforcing material is expensive, interfacial adhesion issues occur, and simulation values are different from actual values, making it difficult to perform mathematical analysis. However, carbon nanotubes have advantages such as light weight, rigidity, impact resistance, and reduced number of parts compared to metals. Due to these advantages, it has been applied to various products to reduce weight, improve corrosion resistance, and increase impact durability. As the content of carbon nanotubes or carbon fibers increases, the mechanical properties and antistatic and electromagnetic shielding performance improve. It is expected that the amount of carbon nanotubes or carbon fibers can be optimized and applied to various industrial products.