• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1550-1556
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• 2009

The sophisticated technologies, ensuring both stability and curving performance, are required for the medium high speed train running on conventional railway line where tangent and curved section mixed together. We can hardly meet the both requirements conflicting each other with the conventional type of bogie. Effective solution is to apply stabilizing mechanism for the bogie design, which increase hunting stability or dynamically critical speed while maintaining curving performance. In this research the numerical analysis by means of multi-body dynamic simulation S/W, experiments by using roller test rig and main line running test have been comprehensively performed for the 200km/h Korean Tilting Train with newly developed stabilizer. The paper proposes the effectiveness of stabilizer and its usefulness based on the results of analyses.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.255-257
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• 2018

본 논문은 리튬폴리머 배터리를 입력 전압원으로 High-Altitude Electomagnetic Pulse (HEMP) 구동용 고밀도 고전압 충전기의 설계를 다루며, 제안하는 충전기는 독특한 3상 델타-와이 변압기 구조를 갖는 5.4kW 용량의 LCC 공진 컨버터로 제작 되었다. 풀브릿지 형태로 4개의 스위치를 사용하는 단상 충전기는 동일 용량을 설계하는 경우, 입력 전류량이 높아 소자의 발열로 충전기의 동작 시간이 제한되고 누설 인덕턴스에 의한 스파이크성 전압이 크게 발생하여 충전기의 안정적인 구동이 어려운 문제점이 있다. 이를 해결하기 위해 6개의 스위치를 사용하는 삼상 충전기를 HEMP 구동용 고밀도 고전압 충전기에 적용하였다. 동일 용량의 단상과 삼상 충전기 설계과정과 시뮬레이션 결과를 분석해 각 충전기의 차이점을 비교하고, 저항 및 커패시터 부하 실험으로 제안하는 삼상 충전기의 동작과 성능을 검증하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.575-577
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• 1999

In this study, the PPPI(Plasma Polymerized Phenyl Isothiocyanate) resist thin film was manufactured in accordance with the plasma polymerization method and after exposing it to an electron beam, a pattern was formed by plasma etching. With the FT-IR(Fourier transform-infrared spectrometry) analysis, it was confirmed that the PI(Phenl Isothiocyanate) monomer was successsfully produced into a thin film by the plasma. The polymerization rate of the thin film was 450~ 1012($\AA$/min) to 100-200(W) discharge power and 120-12($\AA$/min) to 0.1 ~0.4[torr] system pressure.

• Electronics and Telecommunications Trends
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• v.37 no.1
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• pp.10-20
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• 2022

A drone without attaching guns or bombs can be a dangerous weapon, since its motor speed is greater than 3000 rpm, which is similar to that of a mower powered by a LiPo battery. The anti-drone system is the only means of detecting and neutralizing drone attacks. Many defense companies around the world provide solutions using various types of equipment (for example, radar, cameras, jamming guns, and net guns). ETRI has also developed a Low-Altitude Drone Detection (LADD) system consisting of Ku-band radar and an Electro-Optical/Infra-Red (EO/IR) camera. In this paper, we summarize recent technical advances in anti-drone systems around the world and introduce the features and describe the performance of the LADD system.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.29-32
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• 2003

We introduce the subcategories IRe $l_{PR}$ (H), IRe $l_{PO}$ (H) and IRe $l_{E}$(H) of IRe $l_{R}$(H) and study their structures in a viewpoint of the topological universe introduced by L.D.Nel. In particular, the category IRe $l_{R}$(H)(resp. IRe $l_{P}$(H) and IRe $l_{E}$(H)) is a topological universe eve, Set. Moreover, we show that IRe $l_{E}$(H) has exponential objects.ial objects.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.234-237
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• 2021

최근 인공지능에대한 관심과 COVID-19의 영향으로 인공지능을 적용하려는 연구가 계속되고 있다. 인공지능 학습 방식 중 딥러닝에서는 학습 결과에 따라 가중치를 두며 지속적인 학습을 수행한다. 이때 사용하는 가중치에 따라 학습 능력이 향상되게 되지만, 과다 학습으로 인한 퇴화 현상과 잘못된 결과 도출이 되는 경우가 발생한다. 이를 해결하기 위해 본 논문에서는 문제를 해결하기 위해 비연속적 PoW 합의방식을 사용한 블록체인에 가중치와 학습 결과를 지속적으로 보관하여 형상관리를 할 수 있는 시스템을 설계하였다.

• Journal of Korean Dental Science
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• v.3 no.1
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• pp.11-16
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• 2010

Objective : This prospective study sought to verify the stability of three types of short implants measuring 7mm or less. Materials and methods : Implants measuring 7mm or less were placed in patients at multicenter dental clinics in Korea, China, Taiwan, and Singapore. Initial stability, intraoperative and postoperative complications, crestal bone loss, and survival rate of the implant were prospectively evaluated. Results : The primary stability of a 6-mm implant was lower than that of a 7-mm implant. The marginal bone loss of short implants measuring less than 7mm was minimal. Complications such as wound dehiscence, implant mobility, and peri-implant mucositis developed, and these were associated with initial implant failure. The short-term survival rate of 6-mm implant was 93.7%, and that of 7-mm implant, 96.6%. Conclusion : Short implant for the mandible with insufficient height for the residual ridge can be selectively used. Poor primary stability and wound dehiscence can cause osseointegration failure and alveolar bone loss.

• Korean Journal of Medicinal Crop Science
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• v.14 no.6
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• pp.371-375
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• 2006

To investigate effects on the growth and ginsenosides accumulation in ginseng hairy root, potassium phosphate was supplemented with 1.25, 2.5, and 5.0 mM concentration in 1/2 MS medium, respectively. Potassium phosphate supplement was increased the biomass and ginsenosides accumulation when it was dose at the concentration of 1.25 mM. And the growth rate of hairy root in the light condition was higher than in dark condition. The highest contents and productivity of ginsenosides were observed at the supplement of 1.25 mM potassium phosphate at the 7th day after the culture onset. Ginseng hairy root cultured in 20 L bioreactor supplemented with 1.25 mM KH$_2$PO$_4$ was increased the growth with 1,609 g (F${\cdot}$W) and ginsenosides content with 11.09 mg than those in control.

• Korean Journal of Plant Resources
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• v.33 no.6
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• pp.696-706
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• 2020

Cordyceps has been used in traditional Chinese medicine more than 2000 year ago. In this study, the new Cordyceps militaris was founded and isolated from O-dae mountain in Korea, and was identified its genetic characteristics. The newly isolation strain HB8 was most closet to Cordyceps militaris W141449 (99.82%), Cordyceps militaris JLCY-LI819 (99.82%) and Cordyceps militaris 4642 (99.81%), respectively. the genotypic result was show that train HB8 was belonging to the Cordyceps militaris genus, therefore, Cordycep militaris HB8 proposed with accession number MT835161. This study we find the optimal condition for production of cordycepin from Cordyceps militaris HB8 was 8 mg/g (200 g of pupa, 1 g of KH₂PO₄, 0.5 g of K₂HPO₄, 20 g of glucose, 1 g of MgSO₄, 0.05 g of vitamin B1, and 1 mg of NAA per liter; light condition 300-700 Lux and day/night was 14 h/10 h) and the optimum condition for the production of adenosine was 2.6 mg/g (15 g of skim milk powder, 1 g of KH₂PO₄, 0.5 g of K₂HPO₄, 20 g of glucose, 1 g of MgSO₄, 0.05 g of vitamin B1, and 1 mg of NAA per liter; light condition 300-700 Lux and day/night was 14 h/10 h).

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.329-334
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• 1986

The bacteria capable of utilizing polyethylene glycol(PEG) 6,000 as a sole carbon source were isolated from soil and sewage water connected to factory area. The isolate designated as EL-033 had high biodegradability on PEG 6,000, and was identified as Micrococcus sp. Micrococcus sp. EL-033 could grow on and degrade di-, tri-, tetraethylene glycols and PEGs with molecular weight up to 6,000 and very slowly stilize PEG 20,000 as sole carbon source, but not degrade ethylene glycol. The growth rate of isolate was increased in the higher molecular weight PEGs. The optical culture medium was established to be as follow: PEG 6,000, 0.2%(w/v); $K_2HPO_4$, 0.1%; $NaH_2PO_4{\cdot}12H_2O,\;0.1%\;:\;MgSO_4{\cdot}7H_2O$, 0.05%; polypeptone, 0.1% in distilled water, pH7.5. About 90% of PEG 6,000 was degraded in exponential phase of 48h culture and PEG 6,000 was completely degraded during 72h.