http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Subject Hierarchy Structure Modeling in Data Warehouse
Yixuan Ma,Xuedong Gao,Shujuan Gu 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.4
Data warehouse is subject-oriented organized. However, when data warehousing, the hierarchy structure of subject is currently only decided by decision makers’ intuition. Faced with complicated business data mining cases, it is hard to establish hierarchy structure of subject just according to intuition. Thus a method based on ISM is present to make subject level structure establishment more measurable and illustrative. In this article, the "Subject" level structure establishment process is presented firstly. Then the method is put forward. Finally, the rationality and validity of this method are verified by a case on university financial data warehouse’s subject level establishment.
Lingling Li,Zhenghai Liu,Jiaye Xu,Xuedong Ma 한국전기전자재료학회 2020 Transactions on Electrical and Electronic Material Vol.21 No.3
In order to enhance the segregation eff ect of material particles in a hemispherical shell swing-oscillating trough under combination swing-oscillating, by means of three dimensional discrete element method, and by use of the two-dimensional dry granules of plastic ball and steel ball, the discrete element simulation study of particle segregation process is carried out in turn in three cases, which is composed of a single swing-oscillating in smooth trough, a combination swing-oscillating in smooth trough, and a combination swing-oscillating in adding bulge trough. The particle segregation eff ect was evaluated by particle volume concentration and combined with segregation cloud picture simulated. The result indicates that segregation effect of combination swing-oscillating is better than that in single swing-oscillating; layering eff ect of the trough added bulge is better than that in the smooth trough. And compared to single swing-oscillating in smooth trough, the degree of segregation of particles in added bulge trough can be increased by 10–15% when being combination swing-oscillating.
Bin Du,Haoxiang Li,Wei Zheng,Xuedong He,Tao Ma,Huaqiang Yin 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.1
Air ingress incidents are major safety accidents in very-high-temperature reactors (VHTRs). Air containing a high volume fraction of oxygen may cause severe oxidation of core components at the VHTR, especially for the significantly thin alloy tube wall in the intermediate heat exchanger (IHE). The research objects of this study are Inconel 617 and Incoloy 800H, two candidate alloys for IHE in VHTR. The air ingress accident scenario is simulated with high-temperature air flow at 950 C. A continuous oxide scale was formed on the surfaces of both the alloys after the experiment. Because the oxide scale of Inconel 617 has a loose structure, whereas that of Incoloy 800H is denser, Inconel 617 exhibited significantly more severe internal oxidation than Incoloy 800H. Further, Inconel 617 showed a significant decrease in ultimate tensile strength and plasticity after aging for 200 h, whereas Incoloy 800H maintained its tensile properties satisfactorily. Through control experiment under vacuum, we preliminarily concluded that serious internal oxidation is the primary reason for the decline in the tensile properties of Inconel 617