• International Journal of Railway
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• v.7 no.1
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• pp.24-33
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• 2014

The Korean high-speed rail (HSR) began its commercial service in 2004. This service has been created significant changes in the system of intercity passenger travels of Korea. However, the actual ridership was approximately half of the estimated one in the planning stage. In this background, this paper presents the difference between the stated preference (SP) before the HSR service and the revealed preference (RP) after it using the intercity travel mode choice models. Several meaningful differences are found in terms of the factors affecting the travel mode choice, the estimation results of model, the monetary values of time, and elasticities. While the access/egress travel time of high-speed rail is less important than in-vehicle travel time in the SP sample, they have same weight in the RP sample. Also the RP models show that the probability of choosing HSR can be decreased by the increase of the number of vehicles in household contrary to the results from the SP models. The monetary values of travel time are relatively high and the direct and cross elasticities in response to changes in level-of-service of HSR are relatively low in the RP sample. This Korean case is expected to offer referable material for preparing high-speed rail services in other countries by showing the difference between the SP and RP before/after the actual service, identifying the importance of access/egress travel time and lower direct elasticities of HSR demand.

• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.9-14
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• 1999

• Journal of Korean Society of Transportation
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• v.18 no.4
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• pp.19-30
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• 2000

The purpose of the Paper is to estimate values of transfer related variables on route choices of subway users in Seoul. Four attributes were estimated affecting route choices, i.e. in-vehicle time, transfer time, number of transfers and existence of escalators. Stated preference and revealed preference techniques were used to estimate these values. The values of transfer related variables can be shown by in-vehicle time equivalents. One minute of transfer is 1.5∼2 times one minute of in vehicle times one time of transfer is 10∼15 times, and the existence of escalator is 2∼8 times. Women generally show stronger impedance than men and the elder does than the younger. Working, commuting and educational trips show stronger impedance than others too.

• Journal of Korean Society of Transportation
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• v.10 no.3
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• pp.21-42
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• 1992

As for the travel demand analysis of the past, forcasting has been conducted by the use of revealed preference(RP) informations about actual or observed choices made by individuals. Forcasting method using RP data needs implicit assumptions that there will be no remarkable changes in existing transport conditions. However in case of occuring the great changes in existing conditions or adding a new choice-set of hypothetical options, it is very difficult to predict future travel demand. Fortunately in recent years, especially in the mode choice analysis, it has been perceived that the importance of individual performance data using stated preference(SP) experiments as well as RP data. But the research reports has not been reported sufficiently from models estimated using SP data. Under this background, we analyze the factors affecting the mode choice behavior as a fundamental study against the modelling task with SP choice data. For this analysis, we assumed subway operations in the secondary cities where there are no subway lines until now, and set up a choice-set of hypothetical options based on Experimental Design Method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5D
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• pp.671-677
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• 2011

A diversity of railway network function enhancement projects such as the double tracking, electrification, and direct operation have been actively executed to improve the railway service. When the new rapid transit is provided, how many people will use it instead of other transports? How will the railway choice behavior be changed? Accordingly, in this paper, the applicability of diverted travel demand forecast methods, by Revealed Preference(RP) and Stated Preference(SP) data was reviewed for Daegu metropolitan rail rapid transit service. As the result of combining RP and SP data, including the sequential and simultaneous approach, the total travel time and travel cost parameters are of the right sign and are highly significant. The simultaneous approach is more efficient in terms of the estimation of coefficients. In particular, methods to improve validity of the Mixed RP/SP models, when RP data is used proportionally, the diverted travel demand can be easily identified by railway fare and travel time service level. Therefore, it is considered that this will practically apply even in other regions as well as Daegu metropolitan railway.

• Journal of Korean Society of Transportation
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• v.17 no.2
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• pp.7-19
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• 1999

The Purpose of this study is to analyze the impact of telecommuting-the use of telecommunications technology to perform work from remote sites- on the transportation system. It examined the effects of telecommuting on commuter travel. After reviewing case studies of foreign countries and their telecommuting characteristic, two types of survey, RP(Revealed Preference) and SP (Stated Preference), were carried out in order to analyze the impact of telecommuting on traffic. The RP survey examined respondents'attitudes toward information technology and the characteristics of their work. The SP survey asked respondents what conditions would make them want to become a telecommuter. It was found that higher salaries and communication subsidies would induce more people to telecommute. Overall, it was found that if telecommuting were to be executed in Seoul, 49.1% of workers would become telecommuters, which would result in a 14,407 billion won reduction in direct and indirect transport costs per year. This research proves that traffic congestion can be reduced effectively by instituting telecommuting as an option for workers.

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.265-274
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• 2017

For accurate demand forecasting of railway logistics, we estimated intercity freight mode choice models based on the binary logit model and using production-consumption data from the Korea Transport Database. We estimated two types of models and compared the results by major item of railway logistics, such as container, cement, and steel: 1) The aggregate freight mode choice models are based on the revealed preference (RP) data and 2) The disaggregate models are based on the stated preference (SP) data. With respect to the container, the travel time variable was found to be statistically significant; however, the travel cost variable was not statistically significant in the RP model, while the travel cost variable was statistically significant in the SP model. For cement and steel, the travel cost variables were statistically significant but the travel time variables were not statistically significant in either the RP or the SP models. These results are inconsistent with results from previous studies based on SP data, which showed that the travel time variables were significant. Consequently, it can be concluded that the travel time factor should be considered in container transport, but that this factor is negligible for cement and steel transport.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.119-128
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• 2010

Mode choice behavior is associated with travelers' latent behavior that is an unobservable preference to travel behavior or mode characteristics. This paper specifically addresses the problem of unobservable factors, that is latent behavior, in mode choice models. Consideration of latent behavior in mode choice models reduces the errors that come from unobservable factors. In this study, the authors defined the latent variables that mean a quantitative latent behavior factors, and developed the combined RP/SP model with latent variables using the mode choice behavior survey data. The data has traveler's revealed preference of existent modes along the Han River and stated preference of new water transit on the Han River. Also, The data has travelers' latent behavior. Latent variables were defined by factor analysis using the latent behaviour data. In conclusion, it is significant that the relationship between traveler's latent behavior and mode choice behavior. In addition, the goodness-of-fit of the mode choice models with latent variables are better than the model without latent variables.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.3
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• pp.61-68
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• 2011

유럽연합(EU)은 2012년부터 항공산업에 대해 탄소배출권 거래제도를 적용할 예정이다. 따라서 유럽공항에서 출발 및 도착하는 모든 국제선과 국내선 항공편에 대해 탄소세가 부과될 것이며 이는 한국도 예외는 아니다. 또한 유럽을 운항하는 경우 장거리에 해당되어 중단거리를 운항하는 항공기들에 비해 총 탄소배출량이 더 많으므로 비용부담이 커질 것으로 예상된다. 본 연구는 EU-ETS로 인한 탄소세가 항공요금에 반영된다면 항공여객들이 어느 정도 민감하게 반응할 것이며 이러한 점들이 궁극적으로 한국의 항공시장에 어떤 영향을 미칠 것인지를 파악해 보는데 목적이 있다. 이를 위해 인천국제공항에서 프랑크푸르트 국제공항 노선을 이용하는 승객을 대상으로 직항노선과 중동지역 경유노선을 비교하여 EU-ETS 가격이 반영된 항공요금에 대한 반응을 Revealed Preference (RP)와 Stated Preference (SP) 설문자료와 Logit Model을 사용하여 분석하였다. 본 연구결과는 한국의 항공산업은 물론 2012년부터 부과될 EU-ETS에 대한 항공사들의 전략개발에 도움이 될 것이다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.386-392
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• 2015

The purpose of this study was to evaluate the quality characteristics and antioxidant activities of noodles added with Rehmanniae Radix Preparata powder (RP). Wheat flour noodles were prepared with four levels of RP (0, 2.5, 5, and 7.5%). Moisture absorption of RP added noodles was somewhat greater than that of control. The turbidity of RP noodles decreased according to addition of RP. Hunter L (lightness) and b (yellowness) values of RP added noodles decreased according to addition of RP amount. Textural properties (measured by a texture analyzer), hardness, and springiness of RP noodles up to 5% were not significantly different from those of control. Antioxidant activity of RP added noodles increased according to addition of RP: $IC_{50}$ values of DPPH radical scavenging activity for raw noodles was 3.77 mg/g, whereas values of raw noodles with RP 2.5 and 7.5% were 3.69 mg/g and 2.47 mg/g, respectively. Polyphenol content increased according to addition of RP. Amylogram showed that RP addition increased initial gelatinization temperature, decreased breakdown, and reduced setback and consistency, which indicates protection against retrogradation. The sensory preference test revealed that cooked noodles with added 2.5% RP showed the highest scores for color, odor, taste, and overall preference. It is suggested that RP up to 2.5% could be substituted for wheat flour to improve noodle quality.