• 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.

• Journal of Radiation Protection and Research
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• v.10 no.1
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• pp.29-40
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• 1985

The objectives of present study is to investigate genetic damage of radiation in mammalian male germ cell and. to establish available screening method for determining genetic hazard by radiation. Several methods were employed to measure the genetic damage of radiation as follows: Sperm head counts, frequency occurrence of sperm with abnormal head shape, fertility, activity of LDH-X, and the induction of unscheduled DNA synthesis (U.D.S.) in male mouse were performed with the passing of time after irradiation by making use of the sequence of event that occurs during spermatogenesis. Sperm head counts and activity of LDH-X in testes were gradually reduced by increased radiation dose and with the passing of the time after irradiation. Frequency occurrence of sperm with abnormal head shape, sterile period, and the induction of unscheduled DNA synthesis were increased by increased radiation dose. It is suggested that since germ cell is a direct reflection of genetic complement, the use of male germ cell is rapid and convenient method for measuring genetic damage by radiation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1663-1674
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• 2012

In this paper, we propose a new watermarking technique for copyright protection of stereo image. The proposed technique embeds watermark to the region which corresponds to occlusion of the disparity map to be extracted by the proposed stereo matching and the frequency coefficient with the appropriate value. We use discrete wavelet transform for frequency transform tool. The proposed algorithm consists of stereo matching, watermark rearrange, mark space selection, and watermark embedding/extracting. We tested the experiment about 4 stereo images which are from Middlebury site. We embedded the watermark to 4 stereo images and extracted it from the images after attacks. We also visually analyzed the watermark embedding images in 3D TV environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.10
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• pp.858-864
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• 2012

In South Korea, to effective and systematic response to disasters, the government will build wireless communication network for PPDR(Public Protection and Disaster Relief) on a national level by 2015. To do it, as MOPAS(Ministry of Public Administration and Security) requested the new frequency assignment for PPDR, KCC(Korea Communications Commission) has been examined new frequency allocations about TETRA and WiBro technologies. In this paper, we were defined the technical parameters, were estimated the spectrum of TETRA-TRS requirements for Korean wireless communication of PPDR based on M.2033 methodology recommended by ITU-R.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.6
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• pp.29-36
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• 2005

RFID(Radio Frequency Identification) will be used for recognizing things and offering distinctive information in Ubiquitous environment. But we are not ready to provide security service to RFID. Therefore we propose the approach of safe RFID system which provides the solution for eavesdrop, forgery, and modification based on Pre-Distribution protocol and RC5 security algorithm. First We distributes the secret key to the Tag with the Reader that is major subject on RFID system using Pre-Distribution protocol. Then we will provide to various security services and privacy protection using RC5 security algorithm. The proposed safe RFID system simulated on ATmega128 evaluate environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1A
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• pp.89-97
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• 2002

This paper proposes the adaptive digital watermarking method for the ownership protection of images. The watermarks are inserted to a selected area rather than a whole area. The proposed method reduces the distortion caused by the watermarking process. To select the regions, roughness of the image should be considered because the watermarks in the smooth regions are easily detected through the human eyes. To find the rough regions, Discrete Cosine Transform (DCT) method is used. Generally, the high frequency regions of images are lost by the compression process such as JPEG. So, the watermarks are inserted to the low frequency regions of a selected area by using the proposed method. The proposed method reduce the image loss or distortion brought by the image processing, such as compression, filtering, scaling, addition of noise, cropping, and wavelet transform.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.1
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• pp.1-7
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• 2019

Due to the highly concentrated power plants integrated through the limited transmission lines in Korea, a Special Protection System(SPS) has been applied to stabilize the power systems by instantly tripping the pre-determined generators in a large-scaled power plant when a fault occurs on the drawing transmission lines. Moreover, power outputs of those generators are constrained to avoid any activation of Under Frequency Load Shedding(UFLS) even after those generators are tripped by SPS action. For this, this paper proposes a method for calculating the required capacity of Energy Storage System(ESS) expected to relieve the operating constraints to generators using its fast response for controlling power system frequency. The proposed method uses the generator acceleration energy to derive the stable condition during the SPS action. In addition, its effectiveness is verified by the case studies adopting actual SPS operations in Korean power systems.

• Journal of Radiation Protection and Research
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• v.48 no.3
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• pp.124-130
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• 2023

Background: When bipolar junction transistors (BJTs) are used as switches, their switching characteristics can be deteriorated because the recombination time of the minority carriers is long during turn-off transient. When BJTs operate as low frequency switches, the power dissipation in the on-state is large. However, when BJTs operate as high frequency switches, the power dissipation during switching transients increases rapidly. Materials and Methods: When silicon (Si) BJTs are irradiated by fast neutrons, defects occur in the Si bulk, shortening the lifetime of the minority carriers. Fast neutron irradiation mainly creates displacement damage in the Si bulk rather than a total ionization dose effect. Defects caused by fast neutron irradiation shorten the lifetime of minority carriers of BJTs. Furthermore, these defects change the switching characteristics of BJTs. Results and Discussion: In this study, experimental results on the switching characteristics of a pnp Si BJT before and after fast neutron irradiation are presented. The results show that the switching characteristics are improved by fast neutron irradiation, but power dissipation in the on-state is large when the fast neutrons are irradiated excessively. Conclusion: The switching characteristics of a pnp Si BJT were improved by fast neutron irradiation.