• Title/Summary/Keyword: scale-frequency analysis

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Characterizing Co-movements between Indian and Emerging Asian Equity Markets through Wavelet Multi-Scale Analysis

  • Shah, Aasif;Deo, Malabika;King, Wayne
    • East Asian Economic Review
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    • v.19 no.2
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    • pp.189-220
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    • 2015
  • Multi-scale representations are effective in characterising the time-frequency characteristics of financial return series. They have the capability to reveal the properties not evident with typical time domain analysis. Given the aforesaid, this study derives crucial insights from multi scale analysis to investigate the co-movements between Indian and emerging Asian equity markets using wavelet correlation and wavelet coherence measures. It is reported that the Indian equity market is strongly integrated with Asian equity markets at lower frequency scales and relatively less blended at higher frequencies. On the other hand the results from cross correlations suggest that the lead-lag relationship becomes substantial as we turn to lower frequency scales and finally, wavelet coherence demonstrates that this correlation eventually grows strong in the interim of the crises period at lower frequency scales. Overall the findings are relevant and have strong policy and practical implications.

Determining minimum analysis conditions of scale ratio change to evaluate modal damping ratio in long-span bridge

  • Oh, Seungtaek;Lee, Hoyeop;Yhim, Sung-Soon;Lee, Hak-Eun;Chun, Nakhyun
    • Smart Structures and Systems
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    • v.22 no.1
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    • pp.41-55
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    • 2018
  • Damping ratio and frequency have influence on dynamic serviceability or instability such as vortex-induced vibration and displacement amplification due to earthquake and critical flutter velocity, and it is thus important to make determination of damping ratio and frequency accurate. As bridges are getting longer, small scale model test considering similitude law must be conducted to evaluate damping ratio and frequency. Analysis conditions modified by similitude law are applied to experimental test considering different scale ratios. Generally, Nyquist frequency condition based on natural frequency modified by similitude law has been used to determine sampling rate for different scale ratios, and total time length has been determined by users arbitrarily or by considering similitude law with respect to time for different scale ratios. However, Nyquist frequency condition is not suitable for multimode system with noisy signals. In addition, there is no specified criteria for determination of total time length. Those analysis conditions severely affect accuracy of damping ratio. The focus of this study is made on the determination of minimum analysis conditions for different scale ratios. Influence of signal to noise ratio is studied according to the level of noise level. Free initial value problem is proposed to resolve the condition that is difficult to know original initial value for free vibration. Ambient and free vibration tests were used to analyze the dynamic properties of a system using data collected from tests with a two degree-of-freedom section model and performed on full bridge 3D models of cable stayed bridges. The free decay is estimated with the stochastic subspace identification method that uses displacement data to measure damping ratios under noisy conditions, and the iterative least squares method that adopts low pass filtering and fourth order central differencing. Reasonable results were yielded in numerical and experimental tests.

Characterization of iron oxide scale films using radio frequency waves (전파를 이용한 철산화물 스케일 박막 특성 연구)

  • Muhn, Sung-Jin;Shin, Dong-Sik;Yun, Him-Chan;Park, Wee-Sang
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.3
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    • pp.55-60
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    • 2009
  • This paper deals with the analysis of characteristics of the scale non-uniformly formed on the surface of the steel during the steel production processes. The steel made at the high temperature contacts with the oxygen in the air, so forms the scale immediately. The scale has a role to protect the surface of the steel product as a oxide-layer, but the scale formed non-uniformly spoils the exterior of the steel product and occurs the problems about the next processes. There is a pickling process to remove the scale of the steel products, but the real situation is that the pickling process is not also based on the analysis of the characteristics of the scale. Therefore, this paper describe the procedures of the analysis of the scale more effectively using the radio-frequency wave. Using the radio-frequency wave, this paper introduce the experimentations to analyze the distributions of scale, the junction characteristics between the surface of steel and scale and the distributions of scale on the produced steel coil. Also, according to the simple simulations, this paper proves the proprieties about the above contents.

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A Study on the Development of a Home Pood Production Frequency Scale (식생활 영역의 가정생산빈도 측정도구 개발에 관한 연구)

  • Cha, Sung-Ran
    • Korean Journal of Human Ecology
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    • v.8 no.1
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    • pp.95-107
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    • 1999
  • Difficulties in the measuring home food production activities obstructs development of home production activity related studies. For solving such problems, this study intended to develope a home food production frequency scale. The data were collected from 219 housewives in Taejon. Validity, reliability, correlation, and multiple regression analysis were used to test home food production frequency scale. The scale's validity and reliability were reveled considerable potential for its use to ascertain relationships between home food production activity and other family variables.

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Numerical prediction analysis of propeller bearing force for full-scale hull-propeller-rudder system

  • Wang, Chao;Sun, Shuai;Li, Liang;Ye, Liyu
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.8 no.6
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    • pp.589-601
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    • 2016
  • The hybrid grid was adopted and numerical prediction analysis of propeller unsteady bearing force considering free surface was performed for mode and full-scale KCS hull-propeller-rudder system by employing RANS method and VOF model. In order to obtain the propeller velocity under self-propulsion point, firstly, the numerical simulation for self-propulsion test of full-scale ship is carried out. The results show that the scale effect of velocity at self-propulsion point and wake fraction is obvious. Then, the transient two-phase flow calculations are performed for model and full-scale KCS hull-propeller-rudder systems. According to the monitoring data, it is found that the propeller unsteady bearing force is fluctuating periodically over time and full-scale propeller's time-average value is smaller than model-scale's. The frequency spectrum curves are also provided after fast Fourier transform. By analyzing the frequency spectrum data, it is easy to summarize that each component of the propeller bearing force have the same fluctuation frequency and the peak in BFP is maximum. What's more, each component of full-scale bearing force's fluctuation value is bigger than model-scale's except the bending moment coefficient about the Y-axis.

A Study on the Diachronic Evolution of Ancient Chinese Vocabulary Based on a Large-Scale Rough Annotated Corpus

  • Yuan, Yiguo;Li, Bin
    • Asia Pacific Journal of Corpus Research
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    • v.2 no.2
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    • pp.31-41
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    • 2021
  • This paper makes a quantitative analysis of the diachronic evolution of ancient Chinese vocabulary by constructing and counting a large-scale rough annotated corpus. The texts from Si Ku Quan Shu (a collection of Chinese ancient books) are automatically segmented to obtain ancient Chinese vocabulary with time information, which is used to the statistics on word frequency, standardized type/token ratio and proportion of monosyllabic words and dissyllabic words. Through data analysis, this study has the following four findings. Firstly, the high-frequency words in ancient Chinese are stable to a certain extent. Secondly, there is no obvious dissyllabic trend in ancient Chinese vocabulary. Moreover, the Northern and Southern Dynasties (420-589 AD) and Yuan Dynasty (1271-1368 AD) are probably the two periods with the most abundant vocabulary in ancient Chinese. Finally, the unique words with high frequency in each dynasty are mainly official titles with real power. These findings break away from qualitative methods used in traditional researches on Chinese language history and instead uses quantitative methods to draw macroscopic conclusions from large-scale corpus.

An analysis of transient stability for small scale power system separated from large scale power system at N-2 contingency (2중 상정고장시 대규모 전력계통으로부터 분리된 소규모 전력계통 과도안정도 분석)

  • Yoon, Gi-Seob;Baik, Seung-Do;Gu, Sung-Wan;Lee, Chong-Soo
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.134-135
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    • 2003
  • Abstract in case of the small scale power system separated from large scale power system N-2 contingency, the Over excitation, Under Frequency and Power swing Tripping Relay operate depending on unbalance Of Generation and Load. and then we studied and measured the angle and frequency deviation between generators. moreover, we compared real fault example with simulation results.

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Application of a Non-stationary Frequency Analysis Method for Estimating Probable Precipitation in Korea (전국 확률강수량 산정을 위한 비정상성 빈도해석 기법의 적용)

  • Kim, Gwang-Seob;Lee, Gi-Chun
    • Journal of The Korean Society of Agricultural Engineers
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    • v.54 no.5
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    • pp.141-153
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    • 2012
  • In this study, we estimated probable precipitation amounts at the target year (2020, 2030, 2040) of 55 weather stations in Korea using the 24 hour annual maximum precipitation data from 1973 through 2009 which should be useful for management of agricultural reservoirs. Not only trend tests but also non-stationary tests were performed and non-stationary frequency analysis were conducted to all of 55 sites. Gumbel distribution was chosen and probability weighted moment method was used to estimate model parameters. The behavior of the mean of extreme precipitation data, scale parameter, and location parameter were analyzed. The probable precipitation amount at the target year was estimated by a non-stationary frequency analysis using the linear regression analysis for the mean of extreme precipitation data, scale parameter, and location parameter. Overall results demonstrated that the probable precipitation amounts using the non-stationary frequency analysis were overestimated. There were large increase of the probable precipitation amounts of middle part of Korea and decrease at several sites in Southern part. The non-stationary frequency analysis using a linear model should be applicable to relatively short projection periods.

Analysis of Pain using Visual Analogue Scale Questionnaire (VAS 평가표를 이용한 동통에 대한 분석)

  • Kang Jeom-Deok;Kim Chul-Yong
    • The Journal of Korean Physical Therapy
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    • v.12 no.2
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    • pp.165-174
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    • 2000
  • Objectives : This study was to analysis of pain using visual analogue scale questionnaire. Methods : Questionnaire were completed by 101 adult patients of department relation to simple pain in hospitals of Taegu from March 10, to April 10, 2000. The information was used to estimate multiple regression for the pain related factors association. Results : Visual analogue scale scores of mean was 4.29. work modification scores was 5.50. The scores of 1 month below was mild$(45.16\%)$, 6 months above was discomfort$(56.41\%)$. distressing$(72.73\%)$. and excruciating$(100.0\%)$ in association between present pain index and duration(p=0.002). Visual analogue scale scores was significantly associated with frequency of pain and present pain index. Conclusion : Date from this study support a statistically significant association between visual analogue scores scores and two factors found in other research to increase the relation with pain. This findings may have implications for targeting frequency of pain and present pain index.

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Correlation of Pain and Anxiety (통증과 불안의 관계분석)

  • Kang, Jeom-Deok
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.8 no.2
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    • pp.19-29
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    • 2002
  • Objectives: This study was to analysis of pain using visual analogue scale and self rating anxiety scale questionnaire. Methods: Questionnaire were completed by 83 adult patients of department relation to pain in hospitals of Daegu from June 20, to August 10, 2001. The information was used to estimate multiple regression for the pain and anxiety scale related factors association. Results: Women visual analogue scale 4.6 scores of mean was higher than man 4.3 scores. Man self rating anxiety scale 30.2 scores of mean was higher than women 26.8 scores. The scores of 6 months above was discomfort 51.8, 1 month below was mild 22.1%, 2-3 months was discomfort 10.5%, and 4-5 months was discomfort 9.3% in association between present pain index and duration. Conclusion: Visual analogue scale scores was significantly associated with frequency of present pain index. Self rating anxiety scale scores was significantly associated with frequency of occupation and present pain index.

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