• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.1
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• pp.87-93
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• 2010

RS(10,8) Code by 4-bit symbol was developed to protect the mass memory of STSAT-3 from SEU in orbit. Therefore, one symbol can be corrected for 32-bit data with 8-bit parity configuration. Moreover, scrubbing period and SEU occurrence rate was calculated based on the KITSAT-3 result. A prediction of SEU rates was performed based on the ground experiment results with a proton accelerator in the KIRAMS(Korea Institute of Radiological Medical Sciences).

• Journal of Astronomy and Space Sciences
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• v.18 no.2
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• pp.109-118
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• 2001

KITSAT-1, launched in 1992, passes through Inner Van Allen Radiation Belt in which high energy Protons cause single event upsets(SBUs) in the main memory of KITSAT-1 OBC(On-Board Computer) 186. The present paper compares SEU data from the OBC186 with the AP-8 model of NASA/NSSDC using the Chi-Square method to estimate the SEU threshold energy. Shielding effect by the satellite body has been taken into account to model the proton fluxes at the position of OBC186, and SEUs recorded during the high solar activities have been removed to avoid the spurious result. The result shows that the SEU threshold energy of the main memory of KITSAT-1 OBC186 is estimated to be about $110{pm}10MeV$.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.121-127
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• 2013

Memory devices including SRAM and DRAM are very susceptible to high energy radiation particles in the space. Abnormal operation of the devices is caused by SEE or TID. This paper presents a method to estimate proton SEU cross section representing the susceptibility of the latch circuit that the unit cell of the SRAM and proposes a new latch circuit to mitigate the SEU. 50b shift register was fabricated by using the conventional latch and the proposed latch in $0.35{\mu}m$ process. Irradiation experiment was conducted at KIRAMS by using 43MeV proton beam. It was found that the proposed latch-shift register is not affected by the radiation environment compared to the conventional latch-shift register.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.181.2-181.2
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• 2012

우주공간에서는 solar particle과 galactic cosmic ray에 포함된 proton, electron 및 heavy ion등에 의해 radiation 현상이 발생하는데 이는 각종 전자장비의 성능 감쇄 및 디지털 장비의 내부 정보를 교란을 야기할 수 있다. 특히 메모리의 bit 정보가 반전되는 Single Event Upset (SEU)의 경우 인공위성 및 우주정거장 등의 시스템에서도 빈번히 발생할 수 있으며 적절한 조치가 이루어지지 않으면 주어진 임무 수행 실패는 물론 시스템 failure까지 이를 수 있다. 따라서 SEU에 의한 문제 발생 시 신속한 문제 확인 및 대처가 매우 중요하다. 본 논문에서는 SEU의 발생 원인 및 영향과 기존의 오류 검출 및 수정 기법에 대해 소개하도록 한다. 또한 효율적이고 신뢰성 있는 설계를 위해 각 하드웨어 소자 특성에 따른 적합한 SEU 회피 방안을 제시하도록 한다.

• Journal of Astronomy and Space Sciences
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• v.18 no.2
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• pp.163-173
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• 2001

In this paper, space radiation environment and single event effect(SEE) have been analyzed for the KOMPSAT-2 operational orbit. As spacecraft external and internal space environment, trapped proton, SEP(solar energetic particle) and GCR(galactic cosmic ray) high energy Protons and heavy ions spectrums are analyzed. Finally, SEU and SEL rate prediction has been performed for the Intel 80386 microprocessor CPU that is planned to be used in the KOMPSAT-2. As the estimation results, under nominal operational condition, it is predicted that trapped proton and high energetic proton induced SBU effect will not occur. But, it is predicted that heavy ion induced SEU can occur several times during KOMPSAT-2 3-year mission operation. KOMPSAT-2 has been implementing system level design to mitigate SEU occurrence using processor CPU error detection function of the on-board flight software.

• Herbal Formula Science
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• v.16 no.1
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• pp.15-27
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• 2008

This report describes 46 studies related to the use of Fructus Ponciri Seu Aurantii main blended prescriptions from Dongeuibogam. The following conclusions were reached through investigations on the prescriptions that use Fructus Ponciri Seu Aurantii as a key ingredient. 1. 19.6% of feces recorded the largest number of clinical frequency of the prescriptions in therapeutic use when Fructus Ponciri Seu Aurantii was taken as a monarch drug in prescriptions. In addition, 13.0% of each of a cough and an abdominal mass with distention and pain ranked second. 2. Prescriptions that utilize Fructus Ponciri Seu Aurantii as the main ingredient are used in the treatmeant of 5 diseases related to each of feces and an abdominal mass with distention and pain, and they are also used for treating different types of diseases related to the following ; a cough, a chest, ribs, eyes, the fullness in the chest, Qi, skin areas. 3. In the view of the causative agent of a disease, the prescriptions which are compounded with Fructus Ponciri Seu Aurantii as a monarch drug are related to endogenous agents such as seven emotion, food, deficiency, exogenous agents such as wind-cold pathogen, heat and non-endo-exopathogcnic factors like diseases due to external factors, poison. And in the view of the pathology of a disease, they are applied to the viscera pathology related to the lung, the spleen and stomach, the pathology of Qi and blood related to the reversed flow of Qi, the congestion of Qi, the deficiency of blood, the obstruction of Qi and blood, and the pathology about the retention of phlegm and fluid related to phlegm stagnation. 4. The dosage of Fructus Ponciri Seu Aurantii is 1.25pun(about 0,47g) to 2jeon(about 7.5g), however 1jeon(about 3.75g) has been taken the most for clinical application. 5. We can find out that according to herbs or prescriptions blended with itself, Fructus Ponciri Seu Aurantii makes a variety of functions to penetrate and remove stagnation, regulate Qi flow, relieve stagnation, expell wind and get rid of pain.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2295-2297
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• 2003

The major problem encountered in satellite design is EMI (Electro-Magnetic Interference) and EMC (Electro-Magnetic Compatibility). Here, our focus is on the effects of protons on the electronic system. The SEU (Single Event Upset) results from the level change of stored information due to photon radiation and temperature in the space and the nuclear power plant environment. The impact of SEU on PLD (Programmable Logic Devices) technology is most apparent in ROM/SRAM/DRAM devices wherein the state of storage cell can be upset. In this paper, a simple and powerful test techniques is suggested, and the results are presented for the analysis and future reference. The test results are compared with that of JPL test report. In our experiment, the proton radiation facility available at KIRAMS (Korea Institute of Radiological Medical Sciences) has been applied on a commercially available SRAM manufactured by Hynix Semiconductor Company.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.1098-1101
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• 2004

This study was carried out to investigate the solubility of the ingredients of the kidney stone in the solution of the traditional oriental medicines. Calcium hydroxide, apatite and uric acid were chosen as the ingredients of the kidney stone. Plantaginis Semen, Lysimachiae Herba, Saururi Herba seu Rhizoma, Imperatae Rhizoma, Allium tuberosum Rottler were studied as the oriental medicines for the kidney stone. Calcium hydroxide had showed the very good solubility in the solution of Imperatae Rhizoma, the apatite had showed the good solubility in the solutions of Saururi Herba seu Rhizoma and Allium tuberosum Rottler. Uric acid had showed the mild solubility in the solution of Lysimachiae Herba and Saururi Herba seu Rhizoma.

• International Journal of Aeronautical and Space Sciences
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• v.5 no.2
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• pp.28-34
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• 2004

One of the major problem encountered in nuclear plants and satellites design isEMI (Electro-Magnetic Interference) and EMC (Electro-Magnetic Compatibility).Here, our focus is to implement the test board for checking SEU (Single EventUpsets); the effects of protons on the electronic system. The SEU results from thelevel change of stored information due to photon radiation and temperature in thespace environment. The impact of SEU on PLD (Programmable Logic Devices)technology is most apparent in ROM/SRAM/DRAM devices wherein the state ofstorage cell can be upset. In this paper, a simple and powerful test techniques issuggested, and the results are presented for the analysis and future reference. In ourexperiment, the proton radiation facilitv (having the energy of 50 MeV with a beamcurrent of 60 uA of cyclotron) available at KIRAMS (Korea Institute of RadiologicalMedical Sciences) has been applied on a commercially available SRAM manufacturedby Hynix Semiconductor Company.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.8
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• pp.1440-1446
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• 2008

In this paper, a novel TMR (Triple Modular Redundancy) memory structure is proposed using state feedback control of asynchronous sequential machines. The main ability of the proposed structure is to correct the fault of SEU (Single Event Upset) asynchronously without resorting to the global synchronous clock. A state-feedback controller is combined with the TMR realized as a closed-loop asynchronous machine and corrective behavior is operated whenever an unauthorized state transition is observed so as to recover the failed state of the asynchronous machine to the original one. As a case study, an asynchronous machine modelling of TMR and the detailed procedure of controller construction are presented. A simulation results using VHDL shows the validity of the proposed scheme.