• Nuclear Engineering and Technology
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• 제53권12호
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• pp.4014-4021
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• 2021

If safety injection systems (SISs) do not work in the event of a loss-of-coolant accident (LOCA), the accident can progress to a severe accident in which the reactor core is exposed and the reactor vessel fails. Therefore, it is considered that a technology that provides recoverable maximum time for SIS actuation is necessary to prevent this progression. In this study, the corresponding time was defined as the golden time. To achieve the objective of accurately predicting the golden time, the prediction was performed using the deep fuzzy neural network (DFNN) with rule-dropout. The DFNN with rule-dropout has an architecture in which many of the fuzzy neural networks (FNNs) are connected and is a method in which the fuzzy rule numbers, which are directly related to the number of nodes in the FNN that affect inference performance, are properly adjusted by a genetic algorithm. The golden time prediction performance of the DFNN model with rule-dropout was better than that of the support vector regression model. By using the prediction result through the proposed DFNN with rule-dropout, it is expected to prevent the aggravation of the accidents by providing the maximum remaining time for SIS recovery, which failed in the LOCA situation.

• 한국주조공학회지
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• 제37권1호
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• pp.1-13
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• 2017

The purpose of this study is to increase the part recovery rate (to more than 70%) during the casting of a ductile cast iron turbo charger housing using a heater around the riser. Before creating a casting mold, various runner and riser systems were designed and analyzed with a casting simulation analysis tool. The design variables were the heater temperature, top insulation, riser location, riser diameter and the riser shape. During the feeding from the riser to the part, the reverse model was better than the forward model. When heating the riser (above $600^{\circ}C$), solidification of the riser was delayed and the feeding effect was suitable compared to that without heating. At a higher heating temperature, less solidification shrinkage and porosity were noted inside the part. On the basis of a casting simulation, eight molds were fabricated and casting experiments were conducted. According to the experimental conditions, external and internal defects were analyzed and mechanical properties were tested. The ultimate tensile strength and elongation outcome were correspondingly more than 540MPa and 5% after a heat treatment. In addition, a maximum part recovery rate of 86% was achieved in this study.

• 구강회복응용과학지
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• 제29권4호
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• pp.399-406
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• 2013

자연치아와 연결한 임플란트 수복물에서 종종 자연치아의 압하가 보고되곤 하지만 임플란트에 둘러싸인 자연치아의 압하에 대한 보고는 매우 드물다. 56세의 여성을 하악 우측 제1소구치는 임플란트로, 제 2소구치 치근은 포스트 수복 후 지르코니아로 각각 수복했다. 제 1대구치와 제 2대구치는 이미 임플란트로 수복되어 있었다. 기능 4개월 후 제 2소구치의 압하로 인한 대합치와의 간격이 분명히 관찰되었으나 불편감을 비롯한 이상증상은 없었다. 예후에 대한 자세한 설명 후 별다른 조치 없이 경과 관찰을 시작하였다. 3개월 후 치근단 방사선 사진상에서 원위치로의 치아 회복 시작이 관찰되었으며 다시 11개월이 경과한 후 치아의 추가 정출로 교합의 완전한 회복이 이루어졌다. 압하를 인지한지 2년 3개월째 관찰 중이다. 임플란트에 둘러싸인 자연치가 압하되고 저절로 회복되는 과정의 관찰을 통해 압하가 생기는 원인과 저절로 회복된 기전을 추정할 수 있었다.

• 융합보안논문지
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• 제19권3호
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• pp.43-50
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• 2019

초연결사회에서 전력기반시설과 정보통신기반시설은 핵심 국가기반시설 중에서도 핵심이다. 그러나 전력기반시설은 최근에 이슈가 되고 있는 북한의 고 고도 핵 전자기파(HEMP) 위협에 매우 치명적이며, 따라서 공격 이후의 빠른 복구를 통한 복원성은 국가의 생존성과 직결되어 있다. 그러므로 전력기반시설은 다른 어떤 핵심기반시설보다 우선하여 선제적인 방호대책과 조기 복구계획이 수립되어야 한다. 본 논문에서는 HEMP 위협의 특성을 살펴보고, 그에 대한 전력기반시설의 위험성 및 효과적인 주요 방호대책을 살펴보았다. 향후 우리나라의 전력기반시설에 대한 '고출력 전자기파 침해 방지' 관련 법·제도의 제·개정 방향을 정립하는데 도움을 줄 수 있을 것으로 기대한다.

• International Journal of Industrial Entomology and Biomaterials
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• 제15권1호
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• pp.23-33
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• 2007

A simple and reliable cryo technique using desiccation and slow freezing of winter dormant buds was employed for 238 core collection of mulberry germplasm collected from diverse geographical regions and maintained under tropical conditions in the ex situ field gene bank to develop long-term biodiversity conservation for ensuring sustainable utilization of these valuable resources. Desiccation and freezing tolerance of bud grafts and excised shoot apices in the axillary buds of different Morus species under in vivo and in vitro condition indicated species-specific variation and most of the wild Morus species were found sensitive. In vitro regeneration and cryopreservation($-196^{\circ}C$) protocols using differentiated bud meristem like axillary winter dormant buds were worked out for a wide range of Morus species, land races, wild and cultivated varieties. Successful cryopreservation of mulberry winter dormant buds of different accessions belonging to M. indica, M. alba, M. latifolia, M. cathayana, M. laevigata, M. nigra, M. australis, M. bombycis, M. sinensis, M multicaulis and M. rotundiloba was achieved. Among wild species Morus tiliaefolia, and M. serrata showed moderate recovery after cryopreservation. Survival rates did not alter after three years of cryopreservation of different Morus species. ISSR markers were used to ascertain the genetic stability of cryopreserved mulberry, which showed no difference detected among the plantlets regenerated from frozen apices in comparison to the non-frozen material.

• 한국재료학회지
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• 제28권8호
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• pp.466-473
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• 2018

Nickel oxide(NiO) thin films, nanorods, and carbon nanotube(CNT)/NiO core-shell nanorod structures are fabricated by sputtering Nickel at different deposition time on alumina substrates or single wall carbon nanotube templates followed by oxidation treatments at different temperatures, 400 and $700^{\circ}C$. Structural analyses are carried out by scanning electron microscopy and x-ray diffraction. NiO thinfilm, nanorod and CNT/NiO core-shell nanorod structurals of the gas sensor structures are tested for detection of $H_2S$ gas. The NiO structures exhibit the highest response at $200^{\circ}C$ and high selectivity to $H_2S$ among other gases of NO, $NH_3$, $H_2$, CO, etc. The nanorod structures have a higher sensing performance than the thin films and carbon nanotube/NiO core-shell structures. The gold catalyst deposited on NiO nanorods further improve the sensing performance, particularly the recovery kinetics.

• 한국자동차공학회논문집
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• 제20권3호
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• pp.20-25
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• 2012

As a kind of distributed energy system, the co-generation system based Diesel engine using after-treatment device was devised for its environmental friendly and economic qualities. It is utilized in that the electric power is produced by the generator connected to the Diesel engine, and waste heat is recovered from both the exhaust gases and the engine itself by the finned tube and shell & tube heat exchangers. An after-treatment device composed ceramic heater and DOC(Diesel Oxidation Catalyst) is installed at the engine outlet in order to completely reignite the unburned fuel from the Diesel engine. In this study, mutual relation of each experimental condition was derived through minimum number of experiment using Taguchi Design and ANOVA recently used in the various fields. It is found that the total efficiency (thermal efficiency plus electric power generation efficiency) of this system reaches maximum 94.4% which is approximately higher than that of the typical diesel engine exhaust heat recovery system.

• 전자공학회논문지C
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• 제35C권9호
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• pp.11-20
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• 1998

고속 복소수 연산장치는 채널등화, 동기신호 복원, 변조 및 복조 등 디지탈 통신 시스템의 기저대역 신호처리에 필수적인 기능블록이다. 본 논문에서는 redundant binary (RB) 연산과 radix-4 Booth recoding을 결합한 새로운 복소수 승산 알고리듬을 제안한다. 제안되는 복소수 승산 방법은 실수 승산기를 사용하는 기존의 방법과 비교하여 부분곱의 수를 반으로 감소시키며, 단순화된 병렬구조로 구현되므로 고속 동작 및 저전력 소모를 가능하게 한다. 제안된 알고리듬을 적용하여 10-bit operand를 갖는 prototype 복소수 승산-누적기(complex-number multiplier-accumulator ; CMAC) 코어를 0.8-㎛ N-Well CMOS 공정으로 설계, 제작하였다. 제작된 CMAC 칩은 18,000여개의 트랜지스터로 구성되며, 코어부분의 면적은 약 1.60 × 1.93 ㎟이다. 제작된 칩을 테스트 보드에 실장하여 특성을 평가한 결과, 전원전압 V/sub DD/=3.3-V에서 120-MHz의 속도로 동작함을 확인하였으며, 이때의 전력소모는 약 63-mW로 측정되었다.

• BMB Reports
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• 제47권12호
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• pp.679-684
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• 2014

GM-CSF plays a role in the nervous system, particularly in cases of injury. A therapeutic effect of GM-CSF has been reported in rat models of various central nervous system injuries. We previously showed that GM-CSF could enhance long-term recovery in a rat spinal cord injury model, inhibiting glial scar formation and increasing the integrity of axonal structure. Here, we investigated molecular the mechanism(s) by which GM-CSF suppressed glial scar formation in an in vitro system using primary astrocytes treated with TGF-${\beta}$. GM-CSF repressed the expression of chondroitin sulfate proteoglycan (CSPG) core proteins in astrocytes treated with TGF-${\beta}$. GM-CSF also inhibited the TGF-${\beta}$-induced Rho-ROCK pathway, which is important in CSPG expression. Finally, the inhibitory effect of GM-CSF was blocked by a JAK inhibitor. These results may provide the basis for GM-CSF's effects in glial scar inhibition and ultimately for its therapeutic effect on neural cell injuries.

• Bulletin of the Korean Chemical Society
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• 제25권1호
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• pp.109-114
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• 2004

A sensitive method for quantitation of glimepiride in human plasma has been established using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS). Glipizide was used as an internal standard. Glimepiride and internal standard in plasma sample was extracted using diethyl etherethyl acetate (1 : 1). A centrifuged upper layer was then evaporated and reconstituted with the mobile phase of acetonitrile-5 mM ammonium acetate (60:40, pH 3.0). The reconstituted samples were injected into a $C_{18}$ reversed-phase column. Using MS/MS in the multiple reaction monitoring (MRM) mode, glimepiride and glipizide were detected without severe interference from human plasma matrix. Glimepiride produced a protonated precursor ion ([M+H]$^+$) at m/z 491 and a corresponding product ion at m/z 352. And the internal standard produced a protonated precursor ion ([M+H]]$^+$) at m/z 446 and a corresponding product ion at m/z 321. Detection of glimepiride in human plasma by the LC-ESI/MS/MS method was accurate and precise with a quantitation limit of 0.1 ng/mL. The validation, reproducibility, stability, and recovery of the method were evaluated. The method has been successfully applied to pharmacokinetic studies of glimepiride in human plasma.