RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제
      • 좁혀본 항목 보기순서

        • 원문유무
        • 음성지원유무
        • 원문제공처
          펼치기
        • 등재정보
          펼치기
        • 학술지명
          펼치기
        • 주제분류
          펼치기
        • 발행연도
          펼치기
        • 작성언어
        • 저자
          펼치기

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • 군집 별 표준곡선 매개변수를 이용한 치밀오일 생산성 예측 순환신경망 모델

        한동권(Dong-kwon Han),김민수(Min-soo Kim),권순일(Sun-il Kwon) 한국정보통신학회 2021 한국정보통신학회 종합학술대회 논문집 Vol.25 No.2

        치밀오일 미래 생산성 예측은 잔류오일 회수량 및 저류층 거동 분석을 위해 중요한 작업이다. 일반적으로 석유공학적 관점에서 감퇴곡선법을 이용하여 생산성 예측이 이루어지는데, 최근에는 데이터기반의 머신러닝 기법을 이용한 연구도 수행되고 있다. 본 연구에서는 딥러닝 기반 순환신경망과 LSTM, GRU 알고리즘을 이용하여 미래 생산량 예측을 위한 효과적인 모델을 제안하고자 한다. 입력변수로는 치밀오일 생산 시 산출되는 오일, 가스, 물과 이와 더불어 다양한 군집분석을 통해 산출된 표준곡선이 주요 매개변수이고, 출력변수는 월별 오일 생산량이다. 기존의 경험적 모델인 감퇴곡선법과 순환신경망 모델들을 비교하였으며, 모델의 예측성능을 향상시키기 위해 하이퍼파라미터 튜닝을 통해 최적 모델을 도출하였다. Predicting future productivity of tight oil is an important task for analyzing residual oil recovery and reservoir behavior. In general, productivity prediction is made using the decline curve analysis(DCA). In this study, we intend to propose an effective model for predicting future production using deep learning-based recurrent neural networks(RNN). LSTM, and GRU algorithms. As input variables, the main parameters are oil, gas, water, which are calculated during the production of tight oil, and the type curve calculated through various cluster analyzes. the output variable is the monthly oil production. Existing empirical models, the DCA and RNN models, were compared, and an optimal model was derived through hyperparameter tuning to improve the predictive performance of the model.

      • KCI등재후보

        Protective Effects of N-acetylcystenine and Selenium against Doxorubicin Toxicity in Rats

        Yeo-sung Yoon,Sun-don Kim,Min-hye Lee,Heung-shik S.Lee,In-se Lee,Je-kyung Sung,Eun-sung Park 대한수의학회 2003 Journal of Veterinary Science Vol.4 No.2

        Effects of N-acetylcysteine and Selenium against Doxorubicin Toxicity in RatsEun-sung Park, Sun-don Kim1, Min-hye Lee, Heung-shik S. Lee, In-se Lee, Je-kyung Sung and Yeo-sung Yoon*

      • 시멘트 및 고성능AE감수제가 고유동콘크리트의 유동특성에 미치는 효과에 관한 실험적 연구

        박선규,반성수,우영제,김규용,김무한 忠南大學校 産業技術硏究所 1998 산업기술연구논문집 Vol.13 No.1

        The fluidity of high flowing concrete can be affected by numerous parameters which characterize either the cement or the admixture. The reactivity of a cement as determined by its chemical compositions (especially its C₃A content), its fineness and its content in sulfates and alkalies obviously plays a key role in rheology of high flowing concrete in fresh state. Specific properties of high range water reducing AE agent used to enhance the workability of high flowing concrete also exert important influence. The purpose of this experimental study is to investigate and analyze the effect of cement and high range water reducing AE agent in fluidity, setting, compressive strength of high flowing concrete. As a result, we found that fluidity of high flowing concrete is affected greatly by kind of cement and high range water reducing AE agent, also, there is harmonic character between high belite cement and polycarbonic acid high range water reducing AE agent.

      • MOCVD법에 의해 제조된 Fe₂O₃-TiO₂계 산화물 박막의 내식특성에 관한 연구

        李在鉉,杉本克久,許聖康,尹在弘,金顯洙,邊應善 國立 昌原大學校 産業技術硏究所 1998 産技硏論文集 Vol.12 No.-

        Fe₂O₃-TiO₂artificial passive films were formed at the temperatures of 200-350℃ by low pressure MOCVD technique. The relationship between the formation temperature and corrosion resistance of the Fe₂O₃-TiO₂films was examined in acid solutions. Fe₂O₃-TiO₂films deposited above 300℃ were crystalline and the films deposited below 250℃ were amorphous. The dissolution rate of the Fe₂O₃-TiO₂films deposited at 200 and 250℃ decreased with increasing the formation temperature in 5 M HCl, but the films deposited at 300 and 350℃ hardly dissolved in the solution. The films deposited at 200 and 350℃ easily dissolved at cathodic potentials in 1 M H₂SO₄and HCl owing to te selective reduction of iron oxide components in the films. But, the selective reduction in the films deposited at 300 and 350℃ was suppressed. The Fe₂O₃-TiO₂films deposited above 300℃ have higher corrosion resistance than that of the films deposited below 250℃, because the former have high crystallinity and cotain high chemical resistant oxides.

      • SCOPUSKCI등재

        방사선조사 후 유표피암종세포내 칼슘농도의 변화와 apoptosis 발현에 관한 연구

        이삼선,문제운,허민석,박태원,유동수,최순철 大韓口腔顎顔面 放射線學會 1999 Imaging Science in Dentistry Vol.29 No.1

        Purpose: Ionizing radiations have been reported as an apoptosis initiating stimulus in various cells and it has established that sustained elevations in [Ca²+] can lead to DNA fragmentation by Ca²+-dependent endonucleases, ultimately resulting in apoptotic cell death. The previous experiments have been reported by using primarily thymocytes and lymphocytes and the change of [Ca²+] was measured only by minutes or hours respectively. We need to evaluate [Ca²+] in both several minutes and hours after irradiation of radiation of radiation therapy and verify the apoptotic cells. Materials and Methods: We have measured [Ca²+] in human gingival epitheloid cancer cell with 10 Gy irradiation, at minutely intervals and hourly intervals using digitized video-intensified fluorescence microscopy and the fluorescent Ca²+ indicator dye, fura-2. In order to find out that the transient rise in [Ca²+] could induced apoptosis, cells were incubated for 1 hour at 37℃ with TdT enzyme, rinsed and resuspended containing fluorescence and observed under a confocal fluorescence microscope. MTT assay was done to determine cell activity and LDH assay was done to determine the amount of necrotic cells. Results: After irradiation, the transient and temporal increasing of [Ca²+] in the KB cells was founded. Though, there was no change in the intracellular [Ca²+] at 30 minutes and 2 hours after irradiation. We could detect of DNA fragmented cells at 4 hours after 10 Gy irradiated cells. There were no significant differences between 4 hour, 1 day, 3 day cells. There were no significant differences in MTT and LDH assay between the irradiated group and the control group after 4 hours and 1 day. Though after 3 days there were differences in MTT and LDH assay between the irradiated group was significantly decreased than the control group, in LDH assay the number of necrotic cell death of the irradiated was higher than the control group. Conclusion: In KB cells there were incipient and temporal increasing of the [Ca²+] with 10 Gy irradiation and the apoptosis was founded from 4 hours later which was earlier than seeing of the change of the amount of the cellular ability and necrosis.(J Korean Oral Maxillofac Radiol 1999:29:109-117)

      • 시멘트 콘크리트의 건조수축균열 특성

        박제선,윤경구,이주형,김태환,정원경 강원대학교 부설 석재복합신소재 제품연구센터 2000 석재연 논문집 Vol.5 No.-

        콘크리트는 본질적으로 인장강고와 휨강도가 약하며 취성적 성질을 나타내는 결점을 가지고 있으므로 이를 보강할 목적으로 콘크리트에 섬유를 혼입한 섬유보강 콘크리트가 크게 각광받고 있다. 특히 폴리프로필렌 섬유보강은 모르타르 및 콘크리트가 건조나 동해에 의해 수축될 때 구속에 의해 발생되는 인장응력 및 균열을 제어하고 인성의 증가와 충격, 마모, 피로에 대한 저항성, 내구성을 증대시키는 장점을 가지는 것으로 보고 되고 있다. 1축으로 구속된 건조수축의 구속으로 인한 조강형 콘크리트의 잔류응력을 선형모델을 이용하여 예측할 수 있었고 조강형 콘크리트에 섬유보강으로 인한 건조수축 제어효과는 일반큰코리트에 비해 효과가 매우 큰 것으로 나타났다. 따라서 폴리크로필렌 섬유의 혼입으로 인해 콘크리트의 균열제어가 가능하며, 균열 폭이 큰 균열보다는 많은 미세 균열을 유도하는 것을 알 수 있었다. 섬유보강 조강형 큰크리트의 동결융해저항특성은 거의 동해의 손상을 받지 않으며 좋은 내구성을 유지하고 있는 것으로 나타났다. 이는 불규칙하게 배향된 섬유가 공극수의 이동을 효과적으로 제어함으로써 메트릭스 내의 팽창압으로 인한 파괴를 최대한 줄였기 때문이라고 보여진다. 표면손상과 박리저항에 매우 우수하며 저항성을 증진시키는 효과가 뛰어남을 확인할 수 있었다. 따라서, 내구적 측면의 유지, 보수에 있어서도 섬유보강은 그 효과가 큰 것으로 나타났다. To improve the brittle nature of concrete, discrete fibers can be adapted in concrete. Since polypropylene fiber has many advantages in many points on its chemical stability and good durability, its usages have been increased gradually. It has been reported than polypropylene fibers can not only control restrained tensional stresses and cracks, but also increase toughness, resistance to impact, corrosion, fatigue, and durability. Although the polypropylene fiber reinforced concretes with ordinary cement have been studied so much, those with very early strength concretes have not studied at all. Therefore, it is necessary to initiate and conduct the researches for the polypropylene fiber reinforced very early strength concretes which has enough workability and durability. This study of polypropylene fiber reinforced very early strength concrete focused on the investigation each material's effect into strength development with analysis of restrained shrinkage properties with one-dimensional concrete members. The results showed that more optimized mixture combinations could be selected in very early strength concrete by incorporating polypropylene fibers, keeping in same strength levels at urgent repair works. The formation of needle-shape ettringite helps the early strength development, specially at flexural and this enables the repaired concrete structures or pavements to be opened to traffic after 3 hours of concrete placement. A residual stress of early strength concrete caused by one-dimensional restrained drying shrinkage was predicted from linear model. the control of shrinkage crack by fiber reinforcement at early strength concrete was better than that of ordinary portland cement concrete because of bridging effect of fiber at early age and resulting of more hair cracks rather than fewer wider cracks. As a results, this dissertation clearly validated the fiber reinforcement on the strength development and durability of polypropylene fiber reinforced very early strength concrete, and characteristic of restrained shrinkage. The proposed optimized concrete mixtures might be satisfactory applied at the repair works in fields, because of its durability and crack control capacity against freeze-thaw and contraction at early age, respectively.

      • 미세가공 시스템을 이용한 미세 그루브 가공실험

        이선우,이동주,이응숙,제태진 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

        The needs for precision machining of micro to milli parts have been increased as the industry require high quality products, especially for the micro-machining of IT products. The ultra-precision machining system is essential for the micro machining of fine structures, which insures machining accuracy, low systematic and random error and repeatability. In this study, we developed micro machining system, which is equipped with air bearing stage for ultra precision machining and also we present the results of V-grooving experiments, conducted by the developed system, to verify the performance of system. The results show that the machined V-grooving had good accuracy with repeatable stability.

      • KCI등재

        4 학년 아동들의 수학적 문제 설정 활동의 효과

        조제호,신인선 한국수학교육학회 1998 初等 數學敎育 Vol.2 No.2

        We examined two kinds of problem posing, 'problem making' and 'problem modifying' to find which one is more effective for improving mathematical problem solving ability according to the student's learning-levels and sexes. The results showed that 'problem making' is more effective for high and middle-level groups than 'problem modifying'. There was no big difference according to the sexes. These facts implies that making a problem when a situation was presented is more effective to develop problem solving ability than modifying a problem: modifying some conditions and contents of given problem.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼