• Journal of Korean Society of Transportation
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• v.29 no.3
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• pp.7-19
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• 2011

Using 2006 metropolitan household travel survey data, this study analyzes trip behaviors based on a concept of trip chains using both trip purpose and number of trip linkages. For the analysis, trip chains are classified into two groups depending on including commute trips. Each group is further classified into a single linkage (i.e., Origin-Destination trips without any intermediate stop-by) and multiple linkages (Origin-Destination trip with at least one intermediate stop-by). The analysis is conducted using the two-step Nested Logit Model. Computational results identifying the characteristics of single and multiple linkages show that the young, male and office employee drivers tend to have more multiple linkages than single linkages in their trips. In contrast, it is shown that a driver whose monthly income is less than 3,000,000 Korean Won with a longer commute time more likely to make a trip chain with single linkages (p<0.0001).

• Journal of Korea Port Economic Association
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• v.27 no.2
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• pp.195-215
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• 2011

The purpose of this article is to provide data to be utilized for marketing to attract future container cargo to the Korea-China Car Ferry Service and to estimate container traffic for the development of the International Passenger Terminal to be newly built in the Incheon Southern Port. An analysis of container traffic through the Passenger Terminal of Incheon Port showed that the container throughput of Incheon Port comprised 20% of traffic. The export cargo traffic in the International Passenger Terminal, 71.4%, or 111,698 TEU of 156,284 TEU in total, was brought from metropolitan areas. To increase the container traffic of the car ferry service currently concentrated on the metropolitan areas, more endeavor is required to strengthen marketing competence to attract container traffic to other regions apart from the metropolitan areas as well as provide general services.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.563-570
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• 2011

This study analyze the transfer patterns of passengers in Seoul based on transit smart card data that was observed in 2010. The smart card records maximum four times of transfer and reports that approximately 90% of trips were less than one transfer and the remains were more than 2 transfers. We focus on trips with more than 3 transfers to figure out the relationship between transit service and regional connectivities. The results show that the average travel time, distance, fare are 45 minutes, 18.3km, and 1,119(KW) respectively. We develope a map for investigating transfer patterns at a regional level(dong and gu). By doing this, three types of transfers are observed as: 1) trips of which origin and destination is either same or near, 2) trips with short distance, and 3) long distance trip with low transit connectivities.

• Journal of Korean Society of Transportation
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• v.14 no.1
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• pp.43-50
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• 1996

This paper is concerned with assessing goodness of fit of gravity models. The Chi-square test, or one of its asymptotic equivalents, is usually recommended for the purpose. A difficulty that frequently arises, particularly when working with urban travel data, is that the expected number of trips for most origin-destination(O-D) pairs are small. In order to test goodness of fit of gravity model, a simple approach, which depends on the number of O-D pairs and certain trip totals being large, is proposed in this paper. In addition, derivation of variance of Chi-square ratio is proposed to test the confidence interval of Chi-square ratio and application of its results with simulated data set is made to verify the usefulness of the results.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.1
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• pp.23-29
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• 2015

Energy constraints of wireless sensor networks are an important challenge. Data Transmission requires energy. Distance between origin and destination has an important role in energy consumption. In addition, the location of base station has a large impact on energy consumption and a specific method not proposed for it. In addition, a obtain model for location of base station proposed. Also a model for distributed clustering is presented by cluster heads. Eventually, a combination of discussed ideas is proposed to improve the energy consumption. The proposed ideas have been implemented over the LEACH-C protocol. Evaluation results show that the proposed methods have a better performance in energy consumption and lifetime of the network in comparison with similar methods.

• Journal of Korean Society of Transportation
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• v.18 no.5
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• pp.83-97
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• 2000

The traffic management schemes through traffic signal control and information provision could be effective when the link-level data and trip-level data were used simultaneously in analysis Procedures. But, because the trip-level data. such as origin, destination and departure time, can not be obtained through the existing surveillance systems directly. It is needed to estimate it using the link-level data which can be obtained easily. Therefore the objective of this study is to develop the model to estimate O-D demand using only the link flows in highway network as a real time. The methodological approaches in this study are kalman filer, least-square method and normalized least-square method. The kalman filter is developed in the basis of the bayesian update. The normalized least-square method is developed in the basis of the least-square method and the natural constraint equation. These three models were experimented using two kinds of simulated data. The one has two abrupt changing Patterns in traffic flow rates The other is a 24 hours data that has three Peak times in a day Among these models, kalman filer has Produced more accurate and adaptive results than others. Therefore it is seemed that this model could be used in traffic demand management. control, travel time forecasting and dynamic assignment, and so forth.

• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.117-127
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• 2009

This study analyzed the uncertainty of the forecasted link traffic flow, and estimated of the interval link flow using Korea Transport Data Base (KTDB) to consider those risks into the feasibility study. In the paper, the uncertainty was analyzed according to the stochastic variation of the KTDB origin-destination traffic. It was found that the uncertainty of the entire network traffic forecasts was 15.4% in average,. when the stochastic variation of the KTDB was considered. The results showed that the more congested the roads were, the bigger the uncertainty of forecasted link traffic flow were found. In particular, we estimated the variance of the forecasted traffic flow, and suggested interval estimates of the forecasted traffic flow instead of point estimates which were presented in the common feasibility studies. These results are expected to contribute the quantitative evaluation of uncertain road investment projects and to provide valuable information to the decision makers for the transport investment.

• Journal of Korean Society of Transportation
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• v.4 no.2
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• pp.37-58
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• 1986

Since 1960's there have been conducted quite numbers of origin and destination (0-D) surveys in Korea, Most of them, however, were to be said not so successful. In this paper, it was investigated that why the previous 0-D surveys were failed, and that how it could be improved. The findings of this study are: 1. The collection of sample data itself was performed relatively well, but the problem was in the improper expansion methods which were applied. 2. To improve the expansion methods, it should be performed not only the dwelling unit-based sample surveys but also commercial vehicle survey, cordon line survey, screen line counts and other auxiliary travel surveys like transit patronage survey, vehicle miles survey etc. at the same time. 3. To expand the sample surveyed data in a proper way, the adjustment factors should take a disaggregate form and also should be applied not to the specific trips, but to the specific trip makers to avoid the bias which could be caused by the application of adjustment factors in a way that has been used previously. 4. If there is no considerable change in travel patterns, we can synthesize the present 0-D data with past surveyed sample data, using present statistic data in the same way which was developed in this paper when expanding and adjusting sample data.

• Journal of Korea Port Economic Association
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• v.34 no.3
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• pp.93-112
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• 2018

The purpose of this study is to analyze the flow of e-commerce freight transported by maritime transportation for China and to identify the characteristics of cargo by region/item for finding the ways to promote e-commerce export to China. Thus, this study analyzed the e-commerce export and import data on cargo moved via maritime transportation between Korea and China from 2015 to 1Q18, using Origin-Destination(OD) analysis and visualization techniques. The results indicated that the largest number of Chinese e-commerce cargoes were imported at Incheon Port, which has a clearance facility for e-commerce cargo. In the case of Pyeongtaek Port, e-commerce cargo imported from China has transported to Incheon Customs again, causing the inefficiency through the customs clearance process. Unlike the case of e-commerce imports where the final destination is distributed nationwide, e-commerce products exported to China through maritime transportation were found to be mainly confined to Seoul and Gyeonggi provinces, where freight forwarding companies and forwarders are concentrated. In addition, unlike e-commerce import cargoes, e-commerce items exported through maritime transportation were mainly confined to clothing and cosmetics, and export volume was also less than imports. This study provides some possible strategies to increase the volume of freight and to attract export products as follows: i) to diversify products exported to China through e-commerce transshipment, ii) to diversify export items by building the cold chain in e-commerce transport with China.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.135-142
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• 2010

Wireless mesh network, which is an access network technology, adopts ubiquitous features of ad-hoc network that includes capabilities of self-configuration and self-management. This paper proposes a scheme which enables nodes along route in wireless mesh network to authenticate data and verify data integrity. The scheme distinguishes infra-node, which is a network device used to form mesh network, and user node in ad-hoc network, which operates functions as a sender, receiver or relayer, to deploy different authentication scheme. That is, hop-based authentication scheme along route forming wireless backbone differs from authentication scheme for user nodes in route over MANET. The proposed scheme is less complex than previously proposed schemes from the repects of security setup procedures and managements. In addition, the scheme is able to reduce transmission delay from a source to a destination owing to fast authentication over wireless backbone.