• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1D
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• pp.11-15
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• 2010

It is necessary to improve transfer impedance of Urban Rail Station station users in order to increase the usage of public transportation. This study constructed a model for calculating transfer impedance based on bodily sensational transfer time in Urban Rail Station stations and calculated transfer impedance on major Urban Rail Station stations in Korea. The study results show that the addition of 100 meter exterior walking distance increases 2 minute travel time, 100 meter interior walking distance increases 3 minute travel time, 100 stairways increase 4 minute travel time, and escalators decreases 1 minute travel time. The calculated transfer impedance based on bodily sensational transfer time in this study can be utilized as objective criteria to compare transfer conditions of different Urban Rail Station stations and to prioritize them for facility improvement. The calculated transfer impedance also can be used as facility guidelines for designing a new transit center.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.3
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• pp.346-352
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• 2009

UTC (Coordinated Universal Time) has been made by the comparison results and the statistical analysis of primary clocks maintained by national standard institutes. Some kinds of technique have been used for international time transfer; since 1980s the study on methods and development of time transfer has conducted with activation of GPS application. And the more accurate and easier method made it use the official time transfer method for the generation of UTC. But recently TWSTFT (Two-Way Satellite Time and Frequency Transfers) as well as GPS time transfer are increasing in number because the TWSTFT is able to improve the accuracy and precision of time comparison owing to the elimination of the ionospheric and tropospheric delay errors thanks to the reciprocal propagation path. In this paper, we introduce the TWSTFT results by a multi-channel modem comparing with GPS P3-code.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1722-1729
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• 2011

This paper presents an optimization model for revising train timetable based on an existing timetable to improve transfer time at each station. The transfer time consists of walking and waiting time. The model is formulated as a mixed integer programming. The objective function is to minimize the transfer time from one train to another train at each station. To reflect real situations, range of revising departure time is considered as major condition in the model. To validate the effectiveness of the model, rudimentary computational results are included, and the results are analyzed in terms of transfer time.

• Journal of ILASS-Korea
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• v.21 no.2
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• pp.104-110
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• 2016

Main purpose of the current paper is to show results of time lag analysis using phase information of flame transfer function in order to predict combustion instabilities in a gas turbine combustor. The flame transfer function (FTF) is modeled using a commercial Computational Fluid Dynamics (CFD) code (Fluent). Comparisons of the modeled flame shapes with the measured ones were made using the optimized heat transfer conditions and combustion models. The FTF modeling results show a quite good agreement with the measurement data in predicting the phase delay (i.e. time lag). Time lag analysis results using the phase of FTF shows better combustion instability prediction accuracy than using time lag calculated from the steady state flame length.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1699-1706
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• 2011

This study analyzed the level of service on passenger transfer between metro and bus based on transit smart card data obtained in 2010. In order to evaluate the level of service on transfer, we defined the service level specially on transfer time at metro stations. The data of passenger transfer time were used in cluster analysis to classify the service level from A to F. The results show that the average transfer time from metro to bus was 6.45 minutes. The number of stations with level of service A(approximately less than 7 minutes) and B(less than 16minutes) were found to be 215 and 227stations respectively. Also, the number of stations with the level of service C and D (greater than 20 minutes for transfer) were found to be 6 stations where any type of improvement on transfer facilities is required.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2628-2633
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• 2014

BIPM(International Bureau of Weights and Measures) uses GPS Time Transfer technique for UTC(Universal Time Coordinated). Recently, since GLONASS constellation started the service, studies on GLONASS time transfer and combination of GPS and GLONASS time transfer have been conducted. This paper introduces GNSS time, UTC and leap seconds and proposes the time offset results for applicability of leap seconds in GLONASS time transfer.

• Journal of Environmental Science International
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• v.8 no.3
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• pp.349-354
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• 1999

The transfer function was introduced to establish the prediction method for the DO concentration at the intaking point of Kongju Water Works System. In the mose cases we analyze a single time series without explicitly using information contained in the related time series. In many forecasting situations, other events will systematically influence the series to be forecasted(the dependent variables), and therefore, there is need to go beyond a univariate forecasting model. Thus, we must bulid a forecasting model that incorporates more than one time series and introduces explicitly the dynamic characteristics of the system. Such a model is called a multiple time series model or transfer function model. The purpose of this study is to develop the stochastic stream water quality model for the intaking station of Kongju city waterworks in Keum river system. The performance of the multiplicative ARIMA model and the transfer function noise model were examined through comparisons between the historical and generated monthly dissolved oxygen series. The result reveal that the transfer function noise model lead to the improved accuracy.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.11
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• pp.953-957
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• 2001

This paper is concerned with a transfer alignment method for the SDINS under ship motions. Major error sources of transfer alignment are data transfer time-delay, lever-arm velocity and ship body flexure. Specifically, to reduce alignment errors induced by measurement time-delay effects, the error compensation method through delay state augmentation is suggested. A linearized error model for the velocity and attitude matching transfer alignment system is first derived by linearizing the nonliner measurement equation with respect to its time delay and augmenting the delay state into the conventional linear state equations. And then it is shown via observability analysis and computer simulations that the delay state can be estimated and compensated during ship motions resulting in considerably less alignment errors.

• Journal of Power System Engineering
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• v.3 no.1
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• pp.74-79
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• 1999

This paper describes formulation for algorithm of time historical response analysis of vibration for straight-line structure. This method is derived from a combination of the transfer stiffness coefficient method and the Newmark method. And this present method improves the computational accuracy of the transient vibration response analysis remarkably owing to several advantages of the transfer stiffness coefficient method. We regarded the structure as a lumped mass system here. The analysis algorithm for the time historical response was formulated for the straight-line structure containing crooked, tree type system. The validity of the present method compared with the transfer matrix method and the Finite Element Method for transient vibration analysis is demonstrated through the numerical computations.

• Journal of Welding and Joining
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• v.12 no.4
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• pp.76-84
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• 1994

Droplet transfer modes due to welding conditions and the effect of Ca in welding wire on droplet transfer were investigated. Droplet transfer mode in CO$_{2}$ welding was classified into 2 modes, that is, short circuit and globular transfer, with increasing welding current and voltage. With increasing Ca content in wire, repulsive pressure due to vaporization of Ca was considerably increased. In short circuit transfer region, arcing time was increased and droplet transfer cycle was decreased, with increasing Ca content. In globular transfer region, welding condition for globular transfer was lower current region, with increasing Ca content.