• Title/Summary/Keyword: interval eigenvalue analysis

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Evaluation Method of College English Education Effect Based on Improved Decision Tree Algorithm

  • Dou, Fang
    • Journal of Information Processing Systems
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    • v.18 no.4
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    • pp.500-509
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    • 2022
  • With the rapid development of educational informatization, teaching methods become diversified characteristics, but a large number of information data restrict the evaluation on teaching subject and object in terms of the effect of English education. Therefore, this study adopts the concept of incremental learning and eigenvalue interval algorithm to improve the weighted decision tree, and builds an English education effect evaluation model based on association rules. According to the results, the average accuracy of information classification of the improved decision tree algorithm is 96.18%, the classification error rate can be as low as 0.02%, and the anti-fitting performance is good. The classification error rate between the improved decision tree algorithm and the original decision tree does not exceed 1%. The proposed educational evaluation method can effectively provide early warning of academic situation analysis, and improve the teachers' professional skills in an accelerated manner and perfect the education system.

Small signal stability analysis of oscillations caused by switching operations of SVC (SVC의 스위칭 동작에 의해 발생되는 진동현상의 미소신호 안정도 해석)

  • Kim, Deok-Young
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.495-497
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    • 2005
  • A new small signal stability analysis method for eigenvalue analysis is presented. This method is called RCF method and based on the computation of the state transition equations and state transition matrix over a specified time interval that corresponds to one or some cycle operations of the system. This method is applicable to any system with or without switching elements. As an applicable example of RCF method in power system, the one machine infinite bus system connected switching SVC at generator terminal is investigated and the results proved that variations of oscillation modes after switching operations can be calculated exactly.

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Small signal stability analysis using RCF method (RCF법을 사용한 미소신호 안정도 해석방법)

  • Kim, Deok-Young;Meliopoulos, A. P. Sakis
    • Proceedings of the KIEE Conference
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    • 2002.11b
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    • pp.94-97
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    • 2002
  • A new small signal stability analysis method for eigenvalue analysis is presented. The method is based on the computation of the transition matrix over a specified time interval that corresponds to one cycle operation of the system The method is applicable to any system with or without nonlinear elements. An applicable example of RCF method is presented and the eigenvalues are compared with those of the conventional state space method to show the exactness of the computed eigenvalues of the new method. Also, the variations of oscillation modes which were caused by the switching operation can be analyzed exactly using RCF method.

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A Study on the Dynamic Response Analysis of Shell Structure with Impulsive Load by Reanalysis Technique (재해석 기법에 의한 충격 하중을 받는 쉘 구조물의 동적 응답 해석에 관한 연구)

  • 배동명
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.29 no.2
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    • pp.132-151
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    • 1993
  • The proposed method in this paper. termed the substructural reanalysis technique, utilizes the computational merits of the component mode synthesis technique and of reanalysis technique for the design sensitivities of the dynamic characteristics of substructurally combined structure. It is shown that the dynamic characteristics of the entire structure can be obtained by synthesizing the substructural eigensolution and the characteristics of the eigensolution for the design variables of the modifiable substructure. In this paper , the characteristics of the eigenvalue problems obtained by this proposed method are compared to exact eigensolution in terms of accuracy and computational efficiency. and the advantage of this proposed method as compared to the direct application of the whole structure and experimental results is demonstrated through examples of numerical calculation for the dynamic characteristics (natural frequencies and mode shapes) of a flexible vibration of thin cylinderical shell with branch shell under 2-end fixed positions, boundary condition. Thin cylinderical shell of overall length 1280mm, external diameter 360mm, thickness 3mm with branch shell is made of mild steel. The load condition for dynamic response in this paper is impulsive load of which magnitude is 10kgf, which have short duration of 0.1 sec. and time interval applied to calculate. $\Delta$T is 1.0$\times$10 super(-4) seconds.

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