http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
H<sub>2</sub>O<sub>2</sub>/HCl 처리한 Ti 임플란트의 생체활성 평가
유재선,권오성,이오연,이민호,송기홍,Yue J. S.,Kwon O. S.,Lee O. Y.,Lee M. H.,Song K. H. 한국재료학회 2005 한국재료학회지 Vol.15 No.5
Surface treatment play an important role in nucleating calcium phosphate deposition on surgical Ti implant. Therefore, the purpose of this study is to examine whether the precipitation of apatite on cp-Ti and Ti alloys are affected by surface modification in HCl and $H_2O_2$ solution. Specimens were then chemically treated with a solution containing 0.1 M HCl and 8.8M $H_2O_2$ at $80^{\circ}C$ for 30 mins, and subsequently heat-treated at $400^{\circ}C$ for 1 hour. All specimens were immersed in the HBSS with pH 7.4 at $36.5^{\circ}C$ for 15 days, and the surface was examined with XRD, SEM, EDX ana XPS. Also, pure Ti, Ti-6Al-4V and Ti-6Al-7Nb alloy specimens with and without surface treatment were implanted in the abdominal connective tissue of mice for 4 weeks. All specimens chemically treated with HCl and $H_2O_2$ solution have the ability to form a apatite layer in the HBSS which has inorganic ion composition similar to human blood plasma. The average thickness of the fibrous capsule surrounding the specimens implanted in the connective tissue was $38.57\;{\mu}m,\;62.27\;{\mu}m\;and\;45.64\;{\mu}m$ in the cp-Ti, Ti-6Al-4V ana Ti-6Al-7Nb alloy specimens with the chemical treatment respectively, and $52.20\;{\mu}m,\;75.62\;{\mu}m\;and\;66.56\;{\mu}m$ in the commercial specimens of cp-Ti, Ti-6Al-4V and Ti-6Al-7Nb without any treatment respectively. The results of this evaluation indicate that the chemically treated cp-Ti, Ti-6Al-4V ana Ti-6Al-7Nb alloys have better bioactivity and biocompatibility compared to the other metals tested.
Co2레이저를 이용한 Ti-6Al-4V합금의 Tin 및 TiC 가스 합금화
송기홍,이오연 ( K . H . Song,O . Y . Lee ) 한국열처리공학회 1996 熱處理工學會誌 Vol.9 No.3
Surface alloying of Ti alloy by CO₂laser is able to produce few hundred micrometers thick TiN or TiC surface-alloyed layer with high hardness on the substrate by injecting reaction gas(N₂or CH₄). Laser surface alloying by means of process control is in many applications essential in order to obtain predictable hardening layer. This research has been investigated the effect of such parameters on TiN and TiC gas alloying of Ti-6Al-4V alloy by CO₂laser. The maximum surface hardness of TiN layer was obtained 1750Hv on the conditions of 0.8㎾ laser power, 0.8m/min scanning speed and 100% N₂atmosphere. However, the maximum hardness of TiC formation layer after laser treatment was about 630Hv. As scanning speed was increased, the hardness and depth of these layers were decreased at constant laser power.
송기홍,이오연 ( K . H . Song,O . H . Lee ) 한국열처리공학회 1998 熱處理工學會誌 Vol.11 No.3
N/A The aim of this study is to investigate the effect of impurity level and fabrication processes on the strength, impact and fracture toughness of 7075, 7050 and 7175 aluminum alloy forgings. A specially processed 7175S-T74 aluminum forgings was superior to a conventionally processed 7075-T73, 7050-T74 and 7175-T74 aluminum forgings in both strength and toughness. The reduction of impurity level of iron and silicon has significantly diminished the size and volume fraction of second phase particles such as Al_7Cu₂Fe and Mg₂Si. A further reduction of the amount of second phase particles has been observed by applying a special fabrication process. This phenomena result from the application of intermediate soaking at higher temperature and more sufficiant hot working temperature than that of a conventional processing.
논문 : 고 Mn계 TWIP 강의 미세조직과 기계적 성질
정종구 ( J. K. Jung ),이오연 ( O. Y. Lee ),박영구 ( Y. K. Park ),김동은 ( D. E. Kim ),진광근 ( K. G. Jin ),김성규 ( S. K. Kim ),송기홍 ( K. H. Song ) 대한금속재료학회 ( 구 대한금속학회 ) 2008 대한금속·재료학회지 Vol.46 No.10
The austenitic Fe-Mn alloys have received considerable attention as a possible candidate for the automotive structural materials due to their high strength and high formability with high elongation. This research investigates the effect of alloying elements on the phase transformation, deformation behavior and mechanical properties in high Mn steels for the development of a high strength high ductility steel. The mechanical stability of austenitic phases is very important for high ductility and it depends largely on the composition of carbon, manganese and aluminum. The dominant deformation mode shifts from TRIP to TWIP mode as the amount of C, Mn and Al is increased. Especially, even a small amount of Al addition facilitates significantly TWIP deformation due to the increase of stacking fault energy in Fe-Mn alloys, this leads to increase the ductility and also decrease the crack sensitivity.
납기와 작업준비비용을 고려한 병렬기계에서 딥러닝 기반의 일정계획 생성 모델
유우식,서주혁,이동훈,김다희,김관호 한국전자거래학회 2019 한국전자거래학회지 Vol.24 No.3
As the 4th industrial revolution progressing, manufacturers are trying to apply intelligent information technologies such as IoT(internet of things) and machine learning. In the semiconductor/LCD/tire manufacturing process, schedule plan that minimizes setup change and due date violation is very important in order to ensure efficient production. Therefore,in this paper, we suggest the deep learning based scheduling generation model minimizes setup change and due date violation in parallel machines. The proposed model learns patternsof minimizing setup change and due date violation depending on considered order using the amount of historical data. Therefore, the experiment results using three dataset dependingon levels of the order list, the proposed model outperforms compared to priority rules. 4차 산업혁명이 진행되면서 제조업에서 사물인터넷(IoT), 머신러닝과 같은 지능정보기술을 적용하는 사례가 증가하고 있다. 반도체/LCD/타이어 제조공정에서는 납기일(due date)을 준수하면서 작업물 종류 변경(Job change)으로 인한 작업 준비 비용(Setup Cost)을 최소화 하는 일정계획을 수립하는 것이 효과적인 제품 생산을 위해 매우 중요하다. 따라서 본 연구에서는 병렬기계에서 딥러닝 기반의 납기 지연과 작업 준비 비용 최소화를 달성하는 일정계획 생성 모델을 제안한다. 제안한 모델은 과거의 많은 데이터를 이용하여 고려되어지는 주문에 대해 작업 준비와 납기 지연을 최소화하는 패턴을 학습한다. 따라서 세 가지 주문 리스트의 난이도에 따른 실험 결과, 본 연구에서 제안한 기법이 기존의 우선순위 규칙보다 성능이 우수하다는 것을 확인하였다.
0.15C-6Mn TRIP강의 미세조직과 기계적 성질에 미치는 역변태 열처리의 영향
홍호,이오연,송기홍,Hong, H.,Lee, O.Y.,Song, K.H. 한국재료학회 2003 한국재료학회지 Vol.13 No.7
In this paper the effect of interstitial heat treatment on the microstructure and mechanical properties was examined both in the 0.15C-6Mn steels and 0.15C-6Mn steels added with Nb or Ti. This result will be applied into the development of a steel which has the properties of high strength and high ductility resulted from the transformation induced plasticity. The strength-elongation combination was increased as the holding time was increased when the temperature is at $625^{\circ}C$. However, the strength-elongation combination was decreased sharply as the holding time was increased when the temperature is at $675^{\circ}C$. The tensile strength and elongation of a reverse transformed steels added with Ti or Nb was 93 kg/$\textrm{mm}^2$ and 40%, respectively. This steel shows higher strength more than 10% of the 0.15C-6Mn steel without loss of ductility. The autenite formed from the reverse transformed treatment has a fine lath type, which has the width size of 0.1-0.3 $\mu\textrm{m}$. The TRIP sequence normally transforms the austenite to martensite, however, some of the sequence will produce retained austenite \longrightarrow deformation twin \longrightarrow martensite
7XXX계 단조재의 피로 및 파괴인성에 미치는 제조공정의 영향
이오연,임재규,송기홍,손영일,은일상,신돈수 ( O . H . Lee,J . K . Lim,K . H . Song,Y . I . Son,I . S . Eun,D . S . Shin ) 한국열처리공학회 1996 熱處理工學會誌 Vol.9 No.3
The purpose of this study is to investigate the effect of impurity level and fabrication processes on the strength, fracture toughness and fatigue resistance of 7075, 7050 and 7175 high strength aluminum forgings. It has been verified that plane strain fracture toughness and fatigue characteristics of a specially processed 7175S-T74 alloy is superior to a conventionally processed 7075-T6/T73, 7050-T74 and 7175-T74 alloys. These beneficial effects primarily arise from two view points, i.e., the effect of reducing the impurity level of iron and silicon has significantly diminished the size and volume fraction of second phase particles such as Al_7Cu₂Fe and Mg₂Si. Futher reduction of the amount of nonequilibrium second phase particles has been observed by applying a special fabrication process.
문병인(B.I. Mun),유성옥(S.W. Ryu),송기홍(K.H. Song),주정선(J.S. Joo),박명순(M.S. Park) 한국정보과학회 1991 한국정보과학회 학술발표논문집 Vol.18 No.2
단일 처리기에서는 어느 프로세스를 스케쥴할 것인가가 중요한 고려사항으로 다루어졌으나, 다중처리기 환경에서는 프로세스를 어느 프로세서에 스케쥴 할 것인가가 중요한 고려사항이다. 본 논문에서는 병렬 프로그램을 지원하며 공유메모리 가지고 있는 밀결합 다중처리기 (Tightly Coupled Multiprocessor)에서 실행되는 쓰레드(thread)의 스케쥴러에 대해 연구하였다. 이 스케쥴러는 서버 스킴을 지원하며, 프로세서캐쉬 실행큐라는 자료구조를 이용, 시분할시 문맥교환에 의한 프로세서캐쉬의 내용이 자주 바뀌는 것을 완화시키도록 실행할 수 있게 하였다.
공유메모리를 이용한 다중 쓰레드 서버를 위한 효율적인 SRPC 기법의 설계
유성욱(S.W. Ryu),육동석(D.S. Yuk),송기홍(K H Song),주정선(J.S. Joo),이진호(J H Lee),박명순(M.S Park) 한국정보과학회 1992 한국정보과학회 학술발표논문집 Vol.19 No.1
현재 운영체제의 주요한 접근방법인 마이크로 커널에 기반한 기법은, 구성한 시스템의 모듈화, 신뢰도(reliability)의 증진, 확장과 보안이 용이, 분산 환경에 잘 적응되는 장점이 있지만, 시스템 서비스가 사용자 영역의 서버와 메시지를 통한 RPC(Remote Procedure Call)를 통해서 이루어지기 때문에 모노리딕(monolithic) 커널에 비해 수행 속도가 늦다는 단점이 있다. 시스템 호출시에 RPC에서 사용되는 메시지는 크기가 한정되어 있고, 시스템 호출은 같은 호스트(host)내에서 한정된 시스템 서버와 이루어지는 경향이 있다. 이러한 특징을 이용해서, 공유메모리를 이용한 다중 쓰레드를 가진 시스템 서버를 위한 개선된 통신기법인 SRPC(Shared-memory Remote Procedure Call) 기법을 설계한다.