• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.9 s.112
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• pp.795-803
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• 2006

In this paper, we studied hierarchical channel coding scheme using unequal error protection method fur consecutively broadcastingservice under the rain attenuation of Ka band satellite broadcasting. Unlike time-sharing methods, which are design for different channel coding scheme in according to different modulation, unequal error protection method is made in such way that minimum distance between signals are different for importance of signals with same modulation. Consequently we proposed optimal method according to performance analysis.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.125-130
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• 2005

This paper suggests an efficient method of protection ratio calculation and shows some calculated results applicable to frequency coordination in microwave relay system networks, and the net filter discrimination (NFD) associated with Tx spectrum mask and overall Rx filter characteristics has been examined to obtain the adjacent channel protection ratio. The protection ratio comprises several factors such as C/N of modulation scheme, noise-to-interference ratio, multiple interference allowance, fade margins of multi-path and rain attenuation, and NFD. According to computed results for 6.7 GHz, 64-QAM, and 60 km at BER $10^{-6}$, fade margin and co-channel protection ratio are 41.1 and 75.2 dB, respectively, In addition, NFD for channel bandwidth of 40 MHz reveals 28.9 dB at the first adjacent channel, which results in adjacent channel protection ratio of 46.3 dB. The proposed method provides some merits of an easy calculation, systematic extension, and applying the same concept to frequency coordination in millimeter wave relay system networks.

• Journal of electromagnetic engineering and science
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• v.6 no.3
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• pp.189-195
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• 2006

In this paper, the derivation of the protection ratio for the digital microwave system with diversity is newly suggested for a basic guidance of initial planning for frequency coordination, and computational results are presented for an actual radio frequency band. The net filter discrimination has been also examined to see the effect of the adjacent channel protection ratio caused by adjacent channel interference. In addition, the protection ratios for the space or frequency diversity system are analyzed in terms of diversity improvement factors to find out an equivalent allowable noise-to-interference ratio (N/I) from degraded fade margin. According to results for 6.2 GHz system, with the space diversity of 25 m distance between antennas or the frequency diversity of ${\Delta}f/f=0.05$, under 64-QAM and 60 km at BER $10^{-6}$, the protection ratio can be greatly reduced in comparison to the non-diversity system. So, assuming that only the same protection ratio as the non-diversity system is kept, it is shown that the system with diversity may get more interference level of N/I allowing from 9.0 to - 5.9 dB or from 6.0 to - 4.3 dB for the space or frequency diversity. In consequence, it is concluded that the diversity system is more robust or tolerable for interferences or fades, which may play an important role in overcoming N/I to some extent.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.2
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• pp.154-160
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• 2009

This paper describes a wide bandwidth RFID tag antenna design for protection of connection part between chip and antenna. A proposed tag antenna size, a resonant frequency and bandwidth are $53{\times}10{\times}1\;mm$, 900 MHz and 800 MHz($500{\sim}1,300\;MHz$) at -10 dB below, respectively. The dielectric materials with different relative permittivity such as polyethylene, glass and silicon were applied for protection of connection part between the proposed antenna and chip on the way of whole and partial housing. The measured return loss and radiation pattern agreed well with the calculation results. The read range of the proposed tag antenna without any housing and of tag antenna with housing covered over all by silicon with 3 mm thickness were observed about 5 m and 4 m, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.6A
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• pp.484-493
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• 2009

For the flexible frequency utilization, cognitive radio technique has been prominently considered. The most important requirement in cognitive radio networks is to protect the communications of primary users. Spectrum sensing task by secondary users should be seriously considered in cognitive radio networks, since the spectrum sensing process makes their current quality of service worse. In this paper, we propose the channel sensing scheduling method that keeps the requirements for protecting the primary and guarantee the secondary user's quality of service as possible. The quality of service of secondary user is analyzed in terms of packet delay and loss while the protection-requirements in terms of sensing interval and sensing time predefined. In numerical analysis, we can get appropriate parameters which guarantee QoS in various environment. And simulation results show that this method can improve the performance, delay and the number of transmitted packets against consecutive sensing method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.115-118
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• 2003

In this paper, we analysed the technical characteristics of power line communications interfering marine mobile services. The various radio services including marine mobile potentially affected by unwanted radiation from telecommunication networks as PLT, VDSL, ADSL, etc. The radio spectrum is unique resource. In particular, the frequency range below 30MHz has extremely favourable propagation conditions allowing economic long range as well as low power communication radio services. The paper were as follows to identify marine mobile service that are likely to be affected by PLC and evaluate the protection needs and to investigate methods of measuring the emissions from PLC.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.8
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• pp.690-698
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• 2015

In this paper, we propose a policy orientation for human effects on EMF according to the increasing number of devices which use electromagnetic waves. In particular, we conducted the analysis of the concept of the precautionary principle in advanced foreign countries and case studies which are being applied to the criteria more strict than international standards of protection for vulnerable groups. Futhermore, we analyzed the regulations of the EMF safety zone on KynungGi-Do Regional Council which is not valid in terms of constitutional principles such as superior constitutional and rerservations law principles. In conclusion, we propose to amend or modify any law for vulnerable groups and to implement the EMF-related policy on based Radio Wave Act.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.911-914
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• 2000

본 논문에서는 배터리가 없는 ASK 전송방식의 RFID(Radio Frequency IDentification) Transponder 칩 설계에 관한 내용을 다룬다. Transponder IC는 power-generation 회로, clock-generation 회로, digital block, modulator, overoltge protection 회로로 구성된다. 설계된 칩은 저전력 회로를 적용하여 원거리 transponder칩을 구현할 수 있도록 하였다. 설계된 회로는 0.25㎛ 표준 CMOS 공정으로 레이아웃하여 제작하였다.

• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.282-283
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• 2009

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.189-196
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• 2011

As internet is getting advanced day by day, digital contents have been developed in various areas as killer content in the IT industry. It needs to develop lots of complicated digital content protect systems due to the enhancement and variety of user's multimedia devices. Although there are lots of protect systems based on DRM(Digital Rights Management) technology, it is difficult to provide secure protection because of the problems resulting from analog hole problem, inefficiency of key sharing and various independent protect technologies. Thus, in this paper, we propose a novel authentication and protect system based on RFID(Radio Frequency Identification) technology to solve the problems and show possibility of free content duplication and efficient contents management in smart home environments.