• Title/Summary/Keyword: functional calculus

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Study on the magnetic flux distribution of transformer by the use of finite element method (유한요소법에 의한 변압기의 자속분포 해석에 관한 연구)

  • 임달호;현동석;이철직
    • 전기의세계
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    • v.29 no.4
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    • pp.247-255
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    • 1980
  • In this study, an application of Finite Element Method which, in principle, based on variational calculus has been presented for the two-dimensional analysis of magnetic flux distribution in the shell type core of single phase transformer. The necessary stationarity condition of energy functional and boundary conditions were determined under the assumptions that the electromagnetic field considered is stationary and that the effect of eddy current is negligible. In the process of application the domain of magnetic field was divided into triangle subsectional elements and then the matrix equations were constructed for the respective triangular element and for those of all after the manipulation of minimization process to the vector potential of magnetic field at the each vertex of the element. Furthermore the numerical computation for the equations was guided by the Gaussian Elimination Methods. As the results obtained, it is found that the aspect of magnetic flux distribution inside the core as well as the leakage flux profile at the vicinity of the inner leg of the core is not much different from the well-known distribution profile of magnetic flux, however, the procedure shows to possess the merit of the uniquely deterministic nature for the flux distribution at the desired points.

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Implant restoration considering maintenance for a patient with excessive crown height space (과도한 치관높이 공간을 가진 환자에서 유지관리를 고려한 임플란트 수복증례)

  • Ma, Juri;Yang, Hong-So;Park, Sang-Won;Lim, Hyun-Pil;Yun, Kwi-Dug;Vang, Mong-Sook
    • The Journal of Korean Academy of Prosthodontics
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    • v.51 no.2
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    • pp.107-112
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    • 2013
  • Complications increases when crown height space is excessive and one should be careful of choosing type of fixed prosthesis in case crown height space is over 12 mm. In this condition, tooth seems to be longer, therefore, it is needed to use gingival shade in aesthetically important area for fixed prosthesis. In this case, fixed prosthesis which has inappropriate maintenance and hygiene could hold food, plaque, calculus, thus increase incidence of inflammation and infection. Moreover, it could lead to chronic inflammation and infection and in that case surgical improvement could be necessary. In present case report, gingival inflammation and swelling developed around prosthesis after having made it considering articulation and aesthetic view in patient who had excessive crown height space. Finding out that design of prosthesis is a factor to make it hard to maintain oral hygiene, a temporary prosthesis which has enough interproximal space and proper emergence profile was fabricated. After two months of observation, significant abnormal symptoms are not found and oral reconstruction is performed using fixed prosthesis with zircornia infrastructure and porcelain build-up based on convenient self hygiene design. Through serial treatment, inappropriate soft tissue response is not observed and satisfactory result in functional aspect comes out.