• Korean Journal of Optics and Photonics
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• v.14 no.4
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• pp.406-412
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• 2003

We have developed a radio frequency excited slab waveguide $CO_2$ laser. The dimension of active volume is 2${\times}$40${\times}$400 mm. One concave and one convex mirror are used to make the unstable resonator of the positive branch. The radio frequency is 123 MHz and RF input power is varied from 100 to 900 W. The laser gas is set to a pressure of 10∼60 torr and the mixing ratio is $CO_2$:$N_2$:He=1:1:3. The laser output power of 70.7 W was obtained which corresponds to laser power to RF power conversion efficiency of 9.2%.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.41-44
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• 2004

A RFID(Radio Frequency IDentification) system Is a kind of Radio Frequency Communication System and a branch of Automatic Data Collection System. The RFID System is composed of RF Tag(or Transponder) and RFID Reader(controller). This paper deal with Wireless communications that acquired RF Tag ID by RFID reader, and then target system will transmit Tag ID to RFID Server through the internet using Wireless LAN. The RFID system of Todays are commonly used by a wired RFID system. In this system uses commonly used Wireless LAN, and then we can connect the internet if we have a AP(Wireless Lan Access Point). Internet connection can make a transmission of RF Tag ID, and can make a reception of returning data that are images or information.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1813-1819
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• 2011

In this research, the location positioning system supposed is concerned with range recognition technology using phase and magnitude of radio wave and adding technology of image histogram by vision. By the proposed technology, we design the radio transmitter and receiver and realize the measurement system, and save the data in disk that is earned from 900Mhz RF signal, middle frequency 450Khz of analog signal. Range information is earned the data through digital signal processing of IF signal. For the estimation of range measured, we analyze the difference between real range and measurement range, and also suggest the method to improve the measurement error using average processing and amplitude properties.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.111-112
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• 2017

MRI는 부분 영역을 자세히 영상화하는 검사임에도 인체에 위해한 RF를 전신에 주고 있다. 이러한 문제점을 개선하기 위해 저자들은 RF차단 방호복을 자제제작하여 적용한 결과 적용 전보다 적용 후가 95% 이상 RF를 차단하였다. 따라서 MRI 검사 시 본 연구의 방호복이 인체의 위해를 줄일 수 있는 최적의 대안임을 알 수 있다.

• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.115-120
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• 1998

The $TiN_x$ thin films were prepared on glass substrate by RF(radio-frequency) magnetron sputtering apparatus from a Ti target in a gaseous mixture of argon and nitrogen. In deposition, a RF power supply was used as a power source with a constant power of 240W, and the substrate was heated to $200^{\circ}C$. The films were obtained at nitrogen flow rates in the range 3-9 seem with a constant argon flow rate of 20 seem. For the films obtained, the chemical binding energy of the films was investigated by XPS (x-ray photoelectron spectroscopy) in order to analyze the chemical nature and composition of the films.

• Journal of Broadcast Engineering
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• v.7 no.3
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• pp.271-276
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• 2002

It is very important to find errors in broadcasted streams because it can help us to find where errors occur. Broadcasted streams may have errors in the RF(radio frequency) or baseband domain. It is very important to fix these errors because it can help to stabilize set-top boxes, provide stable receiving, and give comfortable environments to watch TV. Since 2001, major terrestrial broadcasters in Korea started the DTV broadcasting in Kwan-Ak over Seoul area. In this paper, we provide some analysis on errors in MPEG-based TS streams, PSIP packets, and RF area which may occur in DTV systems and compare this result with that of USA.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.1
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• pp.21-25
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• 1999

The TiN, thin films were prepared on glass substrate by RF(radio-frequency) magnetron sputtering apparatus from a Ti target in a gaseous mixture of argon and nitrogen. In deposition, a RF power supply was used as a power source with a constant power of 240W, and the substrate was heated to $200^{\circ}C$. The films were obtained at nitogen flow rates in the range 3-9 sccm with a constant argon flow rate of 20 secm. For the films obtained, the sheet resistance and the chemical binding energy of the films was observed by four-point-probe method and x-ray photoelectron spectroscopy(XPS) depth profiling respectively. In addition, we investigated the relationship between the surface resistance and the chemical nature of the films.

• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.26-33
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• 2017

A drone performs a mission through remote control or automatic control, which uses wireless communications technology. Recently the increasing use of drones, the drone signal RF detection is necessary. In this paper, we propose an efficient dron RF detection method through simulations considering Wi-Fi, Bluetooth and dedicated protocol dron communication method in ISM(Industry Science Medical) band.. After configuring an environment where a common terminal and a drone signal are mixed, a general terminal and a drone signal are distinguished from each other by using a RF characteristic according to a dron movement. The proposed drone RF detection method is the WRMD(Windowed RSSI Moving Detection) operation and the Doppler frequency identification method. The simulation environments consist to mixed for two signals and four signals. We analysis the performance to proposed drone RF detection technique thorough detection rate.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.403-406
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• 2012

Mobile phones work by transmitting and receiving radio frequency microwave radiation. The radio frequency (RF) emitted by mobile phones is stronger than FM radio signal which are known to cause cancer. Though research and evidence available on the risk of cancer by mobile phones does not provide a clear and direct support that mobile phones cause cancers. Evidence does not also support an association between exposure to radio frequency and microwave radiation from mobile phones and direct effects on health. It is however clear that lack of available evidence of cancer as regards the use of mobile phone should not be interpreted as proof of absence of cancer risk, so that excessive use of mobile phones should be taken very seriously and with caution to prevent cancer.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2019-2022
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• 2016

In the presence of an electrically conducting medical lead, radio frequency (RF) coils in magnetic resonance imaging (MRI) systems may concentrate the RF energy and cause tissue heating near the lead. A novel design for a medical lead to reduce this heating by introducing pins in the lead is presented. Peak 10 g specific absorption rate (SAR) in heart tissue, an indicator of heating, was calculated and compared for both conventional (Medtronic) lead design and our proposed design. Remcom XFdtd software was used to calculate the peak SAR distribution in a realistic model of the human body. The model contained a medical lead that was exposed to RF magnetic fields at 64 MHz (1.5 T), 128 MHz (3 T) and 300 MHz (7 T) using a model of an MR birdcage body coil. The proposed design of adding pins to the medical lead can significantly reduce the heating from different MRI systems.