• Proceedings of the KSR Conference
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• 2000.05a
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• pp.32-42
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• 2000

In this paper, we outlines the basic pricing rules that developed over the years, and illustrates how these rules apply in practice using railway fare, price discrimination in railway travel. we review the problems of rail fare system reflecting the market fare decision and consider fare decision structure and relative fare comparison with other modes of transportation. Specifically, we focus on tile effect of tile “fare varying system with distance”, using the characteristics of long distance transportation modes. And set up the framework for reasonable fare decision under the current circumstances.

• Journal of the Korea Society for Simulation
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• v.7 no.1
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• pp.39-51
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• 1998

In this paper, MVED (Minimum Vehicle's Empty Distance), a new dispatching rule for a Single Loop-Single Vehicle AGV system, is developed. Single Loop-Single Vehicle AGV system consists of segmented bi-directional single loops, in which only one AGV is assigned. The MVED rule is focused on minimizing vehicles empty travel distance. Using simulation, the performance of the MVED is compared with that of existing dispatching rules such as STT/D and MEVTT. The results show MVED rule's better performance than others. ARENA is used as a simulation language.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.40.2-40.2
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• 2019

Measuring distances at cosmological scales is one of the most important, yet most difficult to acquire astronomical quantities, allowing astronomers to determine the expansion rate of the universe. Typically, astronomers have sought to find "standard candles" that have a known intrinsic brightness in order to determine their distance. The most well known standard candles are Type 1a supernova and Cepheid variable stars making the so-called "distance ladder". Here we present a method for determining cosmological distances via light travel-time arguments, which can be extended from nearby sources to very high redshift sources.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.155-158
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• 2003

물류센터의 위치선정문제 및 차량운송계획문제 등 물류시스템계획문제에서 거리산정문제를 매우 중요한 문제이며 물류비용의 주요 요인이 되고있다. 지금까지의 거리산정문제는 기하학적거리 및 지역도로와 교통조건을 고려한 일반거리, lp-Distance, 등의 방법들을 활용하고 있다. 최근에는 GIS(Geographical Information System)기반에서의 2차원 평면상의 GIS거리(2-D 거리)를 사용하는 방법을 많이 활용하고 있다. 이러한 방법은 지형적인 여건과 고도차이에 따른 실제거리와는 많은 차이가 있다. 본 연구에서는 이러한 2D기반의 디지털 맵을 3-D 기반의 디지털 맵으로의 변환을 통해 2D GIS 거리산정 방법을 확장하여 3-D기반의 GIS거리 산정 방법을 개발하였다. 이러한 3가지의 거리산정방법; lp-Distance, 2-D 기반의 GIS거리산정 방법 및 3-D기반의 GIS거리산정 방법을 부산지역의 차량운송계획문제(VRP)에 응용하고 그 결과를 비교 분석하였다.

• International Journal of Highway Engineering
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• v.14 no.6
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• pp.131-138
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• 2012

PURPOSES : Two-lane highways have one lane in each direction, and lane changing and passing maneuvers take place in the opposing lane depending on the availability of passing sight distance. 2001 Korea Highway Capacity Manual (KHCM) is classified into two classes of two-lane highways (Type I, II), and average travel speed and time-delayed rate are used as measures of effectiveness (MOEs). However, since existing two-lane highways have both uninterrupted and interrupted traffic flow-system elements, a variety of free-flow speeds exhibits in two-lane highways. In addition, it is necessary to check if the linear-relationship between volumes and time-delayed rate is appropriate. Then, this study is to reestablish the relationship between average travel speed, time-delayed rate, and flow. METHODS : TWOPAS model was selected to conduct this study, and the free-flow speeds of passenger cars and the percentage of following vehicles observed in two-lane highways were applied to the model as the input. The revised relationships were developed from the computer simulation. RESULTS : In the revised average travel speed vs. flow relationship, the free-flow speed of 90km/h and 70km/h were added. It shows that the relationship between time delayed-rate and flow appeared to be appropriate with the log-function form and that there was no difference in time-delayed rate between the free flow speeds. In addition to revise the relationships, the speed prediction model and the time-delayed rate prediction model were also developed. CONCLUSIONS : The revised relationships between average travel speed, time-delayed rate, and flow would be useful in estimating the Level of Service(LOS) of a two-lane highway.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.241-250
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• 2008

With the ever-growing amount of traffic, there is an increasing need for good quality travel time information. Various existing outlier filtering and missing data imputation algorithms using AVI data for interrupted and uninterrupted traffic flow have been proposed. This paper is devoted to development of an outlier filtering and missing data imputation algorithm by using Toll Collection System (TCS) data. TCS travel time data collected from August to September 2007 were employed. Travel time data from TCS are made out of records of every passing vehicle; these data have potential for providing real-time travel time information. However, the authors found that as the distance between entry tollgates and exit tollgates increases, the variance of travel time also increases. Also, time gaps appeared in the case of long distances between tollgates. Finally, the authors propose a new method for making representative values after removal of abnormal and "noise" data and after analyzing existing methods. The proposed algorithm is effective.

• Journal of Korean Society of Transportation
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• v.28 no.2
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• pp.53-64
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• 2010

This study is aimed at identifying the association of change of travel frequencies with information and communications technologies, commuting behavior for 995 workers in the Korea Capital Region. The study surveyed total 995 commuters whose their individual character, commuting behavior, land use as well as ICTs. The measures of the commuting behavior was comprised of a main commuting mode, a use tern, total travel time, and those of land use was the distance from house/office to subway station, and those of ICTs was data and information collection, communication and leisure, online selling or purchases, finance and a civil application, cellular phone service using capacity and so on. The results indicate that commuting behavior, land use, and ICTs are positively associated to change of travel frequencies. Specifically, longer total travel time, or far from house/office to subway station, tend to reduce commuting behavior and collect data and information through internet

• Journal of Distribution Science
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• v.14 no.7
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• pp.63-70
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• 2016

Purpose - The purpose of this study was to examine the variations in emotions during vacation and to explore if such variations depend on psychological distance perceived by vacationers. We proposed that there are changes in affect balance during the course of vacation as well as the mental construal of psychological distance. Research Design, Data, and Methodology - Repeated measures ANOVA was used to examine the variation in emotion and psychological distance of 66 holiday makers who were traveling to different destination for vacation. Data were collected in 2 months with the help of a travel agency. Results - We find that there are variations in emotions during the vacation at different points in time as well as perceived psychological distance. Also we find some evidence that suggests emotional happiness does depend on perceived mental distance to some extent. Conclusion - Our study replicates the findings of previous studies in a novel way and illustrates the robustness of the nature of emotions during vacation and indicates certain time points where the happiness of vacationers can be enhanced. Perceived psychological distance do have an effect on how happy an individual feels during the vacation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.483-484
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• 2008

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.2
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• pp.95-103
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• 1993

We address a new storage policy, called Skip-k storage, which gives storing priority to the items with relatively higher turnover rates. Applying the policy in storage systems such as AS/RS will reduce expected travel distance considerably. We analyze system behavior and find an appropriate skip size expressed by the system parameters in case arrival rates become larger enough.