• Title/Summary/Keyword: 진동 분석

Search Result 3,886, Processing Time 0.03 seconds

Comovement and Forecast of won/dollar, yuan/dollar, yen/dollar: Application of Fractional Cointegration approach and Causal Analysis of Frequency Domain (한·중·일 환율 사이의 움직임 분석 - 분수공적분과 진동수영역의 인과성 -)

  • Jung, Sukwan;Won, DooHwan
    • International Area Studies Review
    • /
    • v.21 no.2
    • /
    • pp.3-20
    • /
    • 2017
  • Traditional co-integration analysis method is known to be difficult to clearly determine the relationship between the cointegrated variables. This study utilizes a fractional cointegation method and a causal analysis of time and frequency domain among the exchange rates of Korea, China and Japan. The results show that even though traditional cointegration methods did not clarify the existence of cointegration, exchange rates were fractionally cointegrated. Causal analysis of time domain and frequency domain provided somewhat different results, but the yen/dollar was useful for forecasting won/dollar and yuan/dollar. Proper use of causal analysis of frequency domain and fractional cointegration emthods may provide useful information that can not be explained from the traditional method.

A Study on Chaotic Phenomenon in Rolling Mill Bearing (압연기 베어링에서의 카오스 현상에 관한 연구)

  • 배영철
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.11 no.4
    • /
    • pp.315-319
    • /
    • 2001
  • A diagnosis system that provides early warnings regarding machine malfunction is very important for rolling mill so as to avoid great losses resulting from unexpected shutdown of the production line. But it is very difficult to provide e8rly w, ul1ings in rolling mill. Because dynamics of rolling mill is non-linear. This paper shows a chaotic behaviour of vibration signal in rolling mill using embedding method. Phase plane and Poincare map, FFT and histogram of vibration signal in rolling mill are implemented by qualitative analysis and Fractal dimension, Lyapunov exponent are presented by quantitative analysis.

  • PDF

Study on the Allowable Limit of Blasting-induced Vibration for Road Structures and Facilities (도로구조물의 발파진동 허용기준에 관한 연구)

  • Son, Moorak;Hong, Doopyo;Kwon, Ohcheol;Jung, Yeunkwun;Hwang, Youngcheol;Park, Duhee
    • Journal of the Korean Geotechnical Society
    • /
    • v.30 no.12
    • /
    • pp.27-40
    • /
    • 2014
  • This paper is to provide the allowable limit blasting-induced vibration for road structures and facilities. For this purpose, first of all, this study examined various allowable limits of different structures from domestic and foreign countries, investigated related problems of the limits used in the country, and suggested the measures to minimize the related problems. Furthermore, this study proposed the blasting-induced vibration limit of road structures and facilities that could be used in the country from comparing and analyzing the various limits from foreign countries. To verify the proposed limit for a practical use in the field, field cases that had both a vibration magnitude and a damage level were collected and they were compared with the proposed limit. In addition, the proposed limit was also compared with the results of analytical and numerical analyses. The comparison and analysis indicated that the proposed limit of different road structures and facilities is valid for the practical use in the field. From this study, the proposed limit is expected to be used as the limit to estimate the damage levels of road structures and facilities due to blasting-induced vibrations in the field.