• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2689-2693
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• 2014

The control over microstructure in block copolymer thin films using external electric fields has become an interesting research topic. In this article, the effect of nanoparticle on the microdomain alignments in block copolymer (polystyrene-b-poly(2-vinylpyridine)/nanoparticle (Au) thin films under electric fields has been examined with transmission electron microscopy. The homogeneous dispersion of Au nanoparticles into the block copolymer matrix was achieved by surface modification of nanoparticles with compatible ligands. Compared with the phenomenon seen in the pristine block copolymer thin films, a peculiar alignment behavior was observed in the block copolymer/nanoparticle hybrid thin films under electric fields. In addition, the different pathways observed in the pristine and nanoparticle incorporated block copolymer thin films were also monitored as a function of exposure time. This work can provide the fundamental information for understanding microdomain alignment in block copolymer/nanoparticle thin films under external electric fields.

• 전기학회논문지
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• 제62권6호
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• pp.863-869
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• 2013

In this paper, we compared and analyzed for safety 1.2m rectangular anchor block and arch-type root anchor block. First, numerical analysis was performed three-dimensional nonlinear method by numerical model test using finite element analysis program "Visual FEA". Then, measure displacement of the surface of the earth after construct each anchor block at 14M electric pole and increase loads through field verification tests for safety evaluation.

• 한국지반환경공학회 논문집
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• 제13권11호
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• pp.5-10
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• 2012

연약지반 내의 많은 콘크리트 전주가 외부의 힘에 의하여 파괴되어 왔다. 본 연구에서는 근가의 설치심도 및 근가의 개수를 변화시키면서 토압과 변위분석을 실시하여 근가가 콘크리트 전주의 안정성에 미치는 영향을 분석하였다. 근가의 깊이 3가지 중 1.5m 깊이에 설치하는 것이 적절한 것으로 보이며, 2.25m 깊이에 근가를 설치하면 과도한 굴착으로 인한 교란으로 변위가 크게 나타난다. 근가를 깊게 설치할수록 수동영역의 토압은 작아지고 주동토압은 커진다. 두 개의 근가를 설치하면 한 개의 근가를 설치할 때보다 전주의 상단의 변위는 43.8%, 지표에서는 55.6% 감소한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.244-250
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• 2007

The electric train in the first line subway runs faster in the block from Suwon to Cheonan than the general block. The faster run results in the deterioration of ride quality due to the increase of noise and vibration. To reduce the noise and vibration of the electric train, a running test of the electric train was performed in the block from Suwon to Cheonan. The experimental results show that the sources of the noise and vibration basically comes from the irregularity of the railroad track and the connection part between car body and bogie. The possible countermeasure of the high speed electric train can be the reinforcement of the center pivot to have more flexibility and the frequent maintenance of electric train.

• 공업화학
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• 제29권4호
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• pp.395-398
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• 2018

전기장 하에서 유기물은 전기장에 의해 부여된 여러 가지 힘의 영향을 받아서 특이한 거동을 나타낸다. 본 연구에서는, 지금까지 개별적으로 고찰되어 왔던 전기장 하에서의 블록 공중합체와 고분자 블렌드의 미세 거동을 비교 분석하여 특징적인 차이점을 알아보고자 한다. 두 가지 고분자가 공유결합으로 연결된 블록 공중합체와 약한 상호작용으로 혼합된 고분자 블렌드 시스템을 비교대상으로 하였다. 이때, 구성 고분자로는 비슷한 유전상수를 갖는 폴리아크릴로 나이트릴과 폴리메틸메타아크릴레이트를 도입하였다. 유사한 분자량, 같은 농도, 같은 전기장 세기하에서 고분자 블렌드가 전기장에 더욱 민감하게 반응하는 것을 알 수 있었다. 이는 공유결합이 분자의 운동성을 제약하여 전기장에 덜 민감하게 반응하도록 거동하기 때문이다. 본 연구는 고분자 물질의 전기장 하에서의 거동을 이해하는 중요한 정보를 제공할 것이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(I)
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• pp.151-155
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• 2003

In this paper, as the first step to assess and enhance the reliability of Korea High Speed Train, electric traction system is selected and reliability analysis is carried out. The electric traction system is classified into subsystems and functional block diagrams and reliability block diagrams are drawn. Expressions to calculate the reliability are deducted and Mean Kilometer Between Service Failure is calculated using the trial test results on the track. Calculated results show reliability growth of the electric traction system.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.278-290
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• 1997

The purposes of this study were to evaluate and compare the pulpal anesthesia induced by an inferior alveolar nerve block and that by Gow-Gates technique, and to investigate the relationship between pulpal anesthesia and intraoral soft tissue responses. After one side of mandibule was anesthetized with inferior alveolar nerve block or Gow-Gates technique using 2 % lidocaine with 1 : 100,000 epinephrine in 19 volunteers of ages between 24 and 29 (16 males and 3 females, average age 25.9 yrs.), electric pulp tests were done on the canine teeth of the anesthetized side and contralateral one before, at 1 min, continued at every 5 minutes until 60 min, and every 10 minutes until 100 min after completion of local anesthetic injection. Degree of pulpal anesthesia was classified as anesthetic failure, possible anesthesia and complete anesthesia by the criteria based on the thresholds to electric pulp test of contralateral canine and the currents of the electric pulp tester. Subjective signs on the lower lip and tongue were checked and prick-pin tests were done on the buccal gingiva of the first molar, buccal and lingual gingiva of the canine tooth at 5, 10 and 20 min after the completion of anesthetic injection. Thresholds to electric pulp test, degree of pulpal anesthesia and relationship between the pulpal anesthesia and soft tissue responses were analyzed with SPSS, paired t-test, Wilcoxon matched-pairs signed-ranks test and correlation analysis. The results were as follows : No significant differences were found in the peak thresholds to electric pulp test, in the induction time to it and in the depth of pulpal anesthesia between inferior alveolar nerve block and Gow-Gates technique (p>0.05). There was no significant relationship between pulpal anesthesia and soft tissue responses in both inferior nerve block and Gow-Gates technique.

• 공업화학
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• 제28권3호
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• pp.290-293
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• 2017

블록공중합체와 나노입자로 이루어진 박막은 많은 관심을 불러 일으켜 왔다. 그리고, 이 혼성체들의 물성과 거동을 조절하기 위해서 다양한 방법이 접근되어 왔다. 본 연구에서는, 블록 공중합체와 나노입자로 이루어진 복합체를 박막 형태로 제조한 후, 이를 전기장에 조사하여 박막 내부 구조의 변화와 거동을 살펴보고자 한다. 본 실험에서는 폴리스티렌과 폴리(2-비닐피리딘)으로 구성된 블록공중합체를 사용하였고, 영구 쌍극자를 포함하는 CdSe 나노 입자를 그 속에 도입하였다. 이를 스핀코팅을 통해 박막 형태로 제조하였고, 전기장을 조사하여 전자현미경 방법으로 내부의 구조변화를 고찰하였다. 결과적으로 도입된 나노입자는 전기장에 의해 부여된 힘에 영향을 거의 받지 않고 블록공중합체의 내부에 존재하였으며, 공중합체의 내부 미세상은 전기장의 영향을 받아 전기장 방향으로 배향하였다. 이는 향후 이종으로 구성된 나노복합체의 전기장 하에서의 거동을 파악하는 데 도움이 될 것이다.

• International Journal of Advanced Culture Technology
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• 제10권2호
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• pp.233-239
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• 2022

Recently, research is being conducted on the rapid service provision and reliability of the instance-based rather than the existing IP-based structure. Research is mainly conducted through Block cloud, a platform that combines service-centric networking (SCN) and blockchain. In addition, the Internet of Things network has been proposed as a fog computing environment in the structure of the existing cloud computing. Fog computing is an environment suitable for real-time information processing. In this paper, we propose a new Internet network structure based on fog computing that requires real-time for rapid processing of IoT services. The proposed system applies IoTA, the third-generation blockchain based on DAG, to the block cloud. In addition, we want to propose a basic model of the object block chain and check the application services of electric vehicles.

• 소성∙가공
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• 제6권3호
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• pp.192-202
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• 1997

This study presents an effect of number of passes in wire-cut electric discharge machining on fine blanking dies and products. Three part fine blanking dies were produced by the difference of numbers of passes discharge machining. Brake pad was produced, through the die produced like that, the objective of this study is the improvement in surface roughness of die block and punch, life extension of die block, the decrease of second fracture dimensions, the rise of productive.