• 농촌계획
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• 제28권3호
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• pp.1-11
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• 2022

In this study, the magnitude of the influence of word frequency on the change of perception of residents before and after resident competency strengthening education in villages where the rural field forum was conducted was analyzed. The results of analyzing the changes in residents' perceptions of the village development project according to the frequency of words are as follows. It was found that talking about surrounding factors had a greater influence than individual factors of keywords. In addition, the frequency of word use had a positive effect on the resident's perception. It was analyzed that items with high awareness of resident prior to resident competency-enhancing education had a low impact.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.459-463
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• 2003

Waveform inversion requires extracting a reliable low frequency content of seismic data for estimating of the low wave number velocity model. The low frequency content of the seismic data is usually discarded or neglected because of the band-limited response of the source and the receivers. In this study, however small the spectral of the low frequency seismic data is, we assume that it is possible to extract a reliable phase information of the low frequency from the seismic data and use it in waveform inversion. To this end, we exploit the frequency domain finite element modeling and source-receiver reciprocity to calculate the $Frech\`{e}t$ derivative of the phase of the seismic data with respect to the earth model parameter such as velocity, and then apply a damped least squares method to invert the phase of the seismic data. Through numerical example, we will attempt to demonstrate the feasibility of our method in estimating the correct velocity model for prestack depth migration.

• 산업공학
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• 제18권3호
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• pp.333-342
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• 2005

In this paper, we propose an efficient forecasting methodology of the mid and long-term frequency demand in Korea. The methodology consists of the following three steps: classification of basic service group, calculation of effective traffic, and frequency forecasting. Based on the previous studies, we classify the services into wide area mobile, short range radio, fixed wireless access and digital video broadcasting in the step of the classification of basic service group. For the calculation of effective traffic, we use the measures of erlang and bps. The step of the calculation of effective traffic classifies the user and basic application, and evaluates the effective traffic. Finally, in the step of frequency forecasting, different methodology will be proposed for each service group and its applications are presented.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.663-666
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• 2004

An analysis of the annual frequency of collapse(AF) is performed for each bridge pier exposed to ship collision. AF is computed for each bridge component and vessel classification. The summation of AFs computed over all of the vessel classification intervals for a specific component should equal the annual frequency of collapse of the component. The designer should use judgment in developing a distribution of the vessel frequency data based on discrete groupings or categories of vessel size by DWT. In the present study the effect of vessel classification on the annual frequency of collapse in the ship collision risk assessment is investigated by illustrative numerical examples based on the vessel frequency data of the domestic harbor. The DWT interval for larger vessels has more effect on the ship collision risk. Therefore the expert judgement in determining the larger DWT interval is required because the design impact lateral resistances of bridge components depend on the ship collision risk.

• Journal of Electrical Engineering and Technology
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• 제5권1호
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• pp.140-145
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• 2010

The monitoring and the diagnosis of the faults in induction motors starting from the stator current are very interesting, since it is an accessible and measurable quantity. The spectral analysis of the stator current makes it possible to highlight the characteristic frequencies of the faults but in a wide frequency range depending on half the sampling frequency, making it very difficult to monitor on-line the faults. In order to facilitate the use of the relevant frequencies of machine faults we proposed the extraction of the frequency components using two methods, namely, the amplitude and the instantaneous frequency. The theoretical bases of these methods were presented and the results were validated on a test bench with an induction motor of 5.5 kw.

• 영어영문학
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• 제55권3호
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• pp.475-495
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• 2009

In this paper, I discuss some asymmetries of bracketing paradoxes from a corpus-based perspective. Through a critical examination of previous analyses of bracketing paradoxes, it is demonstrated that the cases of apparent asymmetries of bracketing paradoxes are consistently accounted for when combined with the frequency-based parsability in morphological processing. Based on the relative frequency, this paper argues that bracketing paradoxes are well-atttested when their immediate bases are frequent and productive enough to be accessed as a unit and stored as such in memory. This is an extension of Hay 2002 which conducted a comprehensive survey of differential frequency effects in suffix pairs. A frequency-based approach to bracketing paradoxes adopted in this paper can be a challenge to the conventional formal theory by assuming a major role of language use and have the potential to significantly advance our understanding of the asymmetries observed in the real language world.

• 한국수산과학회지
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• 제53권2호
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• pp.209-217
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• 2020

The purpose of this study was to compare the model-predicted and experimentally measured target strength (TS) of golden cuttlefish Sepia esculenta cuttlebones. Ultrasonic signals used to estimate frequency-dependent TS and the speed of sound in cuttlebones were measured by pulse-echo and through-transmission techniques, using a chirp sonar system and an ultrasonic pulser/receiver system under controlled laboratory conditions. The model appeared to slightly underestimate the predicted TS values in the frequency range of 100-160 kHz. However, there was good agreement between the predicted and measured TS values in the frequency range of 160-200 kHz. The significant similarity between the model-predicted and experimentally measured TS values supports the use of the Kirchhoff-ray mode (KRM) model for acoustic scattering analysis of cuttlebones. Accordingly, we concluded that the KRM model can be used as a tool to evaluate the frequency-dependent variability of TS due to changes in golden cuttlefish swimming depth.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.61-63
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• 1999

This paper presents an efficient method for analysis of magnetodynamic system using frequency-dependent parameters. In equivalent electric circuit of linear magnetodynamic system, parameters of inductance and resistance are not constant since they vary with its driving frequency. Once frequency-dependent parameters of equivalent electric circuit for a given system are extracted, they can be used to analyze various characteristics of system. We use the Fourier transform, the high-order sensitivity method and Taylor series in order to efficiently extract the frequency-dependent parameters of magnetodynamic system. The proposed algorithm is applied to an induction heating system to validate its numerical efficiency.

• 정보학연구
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• 제8권4호
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• pp.1-7
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• 2005

Investigations of high frequency current transformer(HF-CT) waveform characteristics of the surface leakage on kaolin polluted EPDM polymer insulators have been performed. This work is part of a program aimed at examining the potential for HF-CT waveform characteristics analysis to provide information about the environment contaminants and environment condition of polymer insulators. The investigation reported examined the HF-CT waveform characteristics at high frequencies. The use of high frequency measurements for on-line applications reduces electrical inference. This work was peformed utilizing HF-CT to monitor of surface polluted discharge. It was found that HF-CT waveform frequency spectrum, magnitude depend on importantly the duration of the surface discharge activity.

• 한국공간구조학회논문집
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• 제15권4호
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• pp.99-105
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• 2015

The serviceability design of the high-rise building is affected by the wind response vibration such as the acceleration, at this time it is important to calculate the natural frequency correctly. Since the suggestion equation of the natural frequency being used in the design phase is not the regression equation obtained from the vibration measurement of the high-rise building, the verification to use for the serviceability design of the high-rise building is necessary. This thesis conducted an ambient vibration measuring on the high-rise building through the mobile-phone application to calculate the natural frequency and suggested a natural frequency approximate expression following the building's height, and compared with the domestic/foreign standard and the result of the eigen-value analysis.