• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.63-74
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• 2010

Recently, there has been increasing demand from academic society in Korea for the improvement of current traffic congestion cost estimation methods. The purpose of this study is to suggest a better way to estimate congestion cost followed by in-depth review regarding traffic congestion. The key improvements proposed in this study include: 1) adding social externality to congestion cost, 2) integrating the green house and environmental pollution impacts with congestion costs, 3) taking non-recurrent traffic congestion costs into account for the assessment, 4) revising the criteria to determining the level of traffic congestion speed, and 5) deciding how to limit congestion measurement period. It is found meaningful that the improvements, notwithstanding difficulties in their real case application, provide invaluable insights in our efforts to change the meaning of congestion cost in an era of sustainable growth.

• Environmental and Resource Economics Review
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• v.12 no.1
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• pp.75-90
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• 2003

In this paper we have shown that a Pigouvian tax is an adequate resolution of congestion externality to attain Pareto optimality using utility maximization. For this objective, taking an open access freeway as an example, we not only derived both marginal private benefit and marginal social benefit, but also assessed the divergence between marginal private benefit and marginal social benefit. As a result, we identified that the amount of a Pigouvian tax should be the same amount as the external time cost, which is the value of the marginal time cost to Individual a incurred by Individual b through freeway congestion. This Pigouvian tax coincides with the profit or wealth maximizing toll suggested by literature on the basis of profit maximization. In addition, because an open access freeway is accounted as common property resource, we proved that average social congestion cost is essentially equal to marginal private congestion cost in our model. Finally, we showed that the optimal value of trip derived in our model is the same as that generated on profit maximization approach.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.4
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• pp.576-591
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• 2019

This study attempts to analyze the effects of distance-accessibility to the complex shopping mall of 'Lotte Mall-Suwon', located at the old central and catchment district of the Suwon station in the Province of Gyeonngi, on the prices of its neighboring apartments within the Gwonseon-gu of Suwon City by using the hierarchical and linear-difference in difference regression method. The results of the analysis are as follows. First, before construction the effects of distance-accessibility show the U-shaped pattern, suggesting that the negative external effects of noise and traffic congestion around the Suwon Station affected the prices of its neighboring apartments within the Gwonseon-gu of Suwon City. Second, the effects of distance-accessibility at different times, such as the construction period and after the opening, are statistically significant only in the latter, indicating the reverse U-shaped pattern unlike before the opening. This means that after the opening of the complex shopping mall its external effects as a leisure and convenience space have a positive effect on the prices of its neighboring apartments within the Gwonseon-gu of Suwon City. Third, the effects of distance-accessibility is at an inflection point around 1.6-1.7 kilometers, which means that the U-shaped distance-decay pattern before construction, while the reverse U-shaped pattern is shown after the opening of opening. The latter implies that apartments that are very close to the mall within the Gwonseon-gu of Suwon City enjoy relatively small positive externalities. Therefore, they are exposed to some negative external effects of noise and traffic congestion, but apartments with some distance apart within the Gwonseon-gu of Suwon City maximize those positive externalities. These results suggest that the effects to distance-accessibility are different from location to location.

• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.524-532
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• 2002

With the recent rapid progress of Internet, the higher speed network is needed to support the exploration of ambient information from text-based to multimedia-based information. Also, demands for additional Layer 3 routing technique, such as Network Address Translator (NAT) and Firewall, are required to solve a limitation of a current Internet address space and to protect the interior network from the exterior network. However, current router-based algorithms do not provide mechanisms to solve the congestion and fairness problems, while supporting the multimedia services and satisfying the user requirements. In this paper, to solve these problems, a new active queue management, called MFRED (Multiple Fairness RED) algorithm, is proposed. This algorithm can efficiently reduce the congestion in a router or gateway based on the Layer 3 routing technique, such as NAT. This algorithm can improve the fairness among TCP-like flows and unresponsive flows. It also works well in fairly protecting congestion-sensitive flows, i.e. fragile TCP, from congestion-insensitive or congestion-causing flows, i.e. robust TCP.

• Environmental and Resource Economics Review
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• v.23 no.2
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• pp.225-248
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• 2014

The purpose of this study is to estimate the optimal tax rate for gasoline in Korea, by utilizing both the parameters for the estimation of the optimal fuel taxes and the theoretical model considering externalities proposed by Parry and Small (2005). The result of simulation shows that the optimum fuel taxes in Korea is calculated in 382 korean won per liter, which is lower than fuel tax rate(529 korean won per liter) currently being imposed. The fuel tax is composed of two types of tax. First is Pigouvian tax caused by negative externality such as traffic congestion and accidents etc. And second is Ramsey tax for optimal commodity sales taxes. We find that Pigouvian tax in Korea is higher than one of U.S. and U.K and Ramsey tax is very small due to the inelastic labor supply comparing to consumption elasticity of fuel. When adjusting the elasticity of labor supply to the UK level, the optimal fuel tax in Korea is very close to the current level of 480 korean won per liter. This paper contributes to suggest the reasonable estimation and discussion in the social optimum fuel tax rates by utilizing the theory and simulation and improve the possibility of the derivation of optimum fuel taxes through both securing the exact parameters and modifying the theoretical model suitable for Korea.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.235-236
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• 2012

국내 최대 규모의 컨테이너 전용 터미널인 K컨테이너터미널이 스마트폰 기능을 터미널운영시스템에 도입하고 있다. "스마트로(SmartLo)"라고 이름 붙여진 모바일 애플리케이션은 컨테이너를 운송하는 화물차 운전기사들이 항만출입을 위한 다양한 정보를 스마트폰에서 확인할 수 있도록 만든 애플리케이션이다. 본 연구에서는 컨테이너터미널 게이트에서 스마트로 모바일 애플리케이션 개발사례를 제시하고자 한다. 스마트로 서비스를 이용함으로써 컨테이너터미널에서는 사전정보 조회를 통하여 외부 정보오류 최소화와 게이트 내 혼잡 해소, 화물에 대한 신속한 반출입을 통한 고객 서비스 증대, 스마트 슬립(e-SLIP)발급으로 슬립 구입비용 절감 등의 효과를 기대할 수 있다. 또한 운송차량은 신속한 게이트 통과로 운송회전율의 향상, 전배 및 셔틀 운송시 화물에 대한 적기 운송이 가능하게 되고, 운송사 입장에서는 효율적인 배차관리가 가능할 것으로 기대하고 있다.

• Journal of Navigation and Port Research
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• v.28 no.1
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• pp.69-74
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• 2004

Container Freight Station(CFS), which would be located inside terminal or outside, plays the role of consolidating less than container load(LCL) cargo gathered from multi shippers and deconsolidating full container load cargo into individual consignment. When CFS is allocated inside terminal it muses several problem such as traffic gam around terminal, high social and logistics cost and deterioration of terminal condition. This study, therefore, tries to evaluate the location of CFS, inside and outside of terminal, with respect to the social and logistics costs.

• Journal of Technology Innovation
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• v.19 no.2
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• pp.153-184
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• 2011

This paper investigates what kind of technological partner firms want to cooperate with in terms of partner location. Two geographical factors are considered. One is geographical proximity, given the tradeoff between the effectiveness of knowledge spillovers in proximity and diverse knowledge absorption from geographically distant partners. The other is how many other firms are co-located with potential partners because it is known that clustering regions can create more technological outputs. Analysis on 2008 Korea Innovation Survey data finds that partner proximity is the single most important factor in choosing a cooperation partner. While firms that are located in a region crowded with related industries prefer proximate partners, others that are surrounded by unrelated industries are more likely to cooperate with distant partners. The findings suggest that geographical proximity matters in partner selection because it not only stimulates knowledge spillovers but also reduces costs involving R&D cooperation such as monitoring costs and information costs. Moreover, firms take into consideration both the benefits and risks of clustering regions. If there are so many unrelated firms that they create agglomeration diseconomies such as congestion costs and unintentional knowledge leakages, firms are more likely to try to find their cooperation partners in other regions.

• Journal of the Korea Society for Simulation
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• v.28 no.4
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• pp.45-56
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• 2019

Literatures have considered mathematical model that change the job order of shipper for improving the operation time of yard crane. However, on the real site, it is impossible to change the job order decided according to the shipper's arrival order. Therefore, operation managers have been utilized the relatively simple strategy that job control is better but the process time of yard crane is longer due to the growth of yard crane's interference time and empty drive time. This study proposed a new yard-crane scheduling approach that decided the job order before the shipper's truck arrived the yard terminal. We utilize the Container Pre-Information Notice estimating the arrival time of truck. We developed the container terminal simulation model for validation of the effect of proposed scheduling approach. The results show that the proposed scheduling reduced the interference delay time and empty moving time of yard crane and shipper's truck delay time.

• Journal of Internet Computing and Services
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• v.23 no.6
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• pp.39-48
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• 2022

Cyberattacks around the world continue to increase, and their damage extends beyond government facilities and affects civilians. These issues emphasized the importance of developing a system that can identify and detect cyber anomalies early. As above, in order to effectively identify cyber anomalies, several studies have been conducted to learn BGP (Border Gateway Protocol) data through a machine learning model and identify them as anomalies. However, BGP data is unbalanced data in which abnormal data is less than normal data. This causes the model to have a learning biased result, reducing the reliability of the result. In addition, there is a limit in that security personnel cannot recognize the cyber situation as a typical result of machine learning in an actual cyber situation. Therefore, in this paper, we investigate BGP (Border Gateway Protocol) that keeps network records around the world and solve the problem of unbalanced data by using SMOTE. After that, assuming a cyber range situation, an autoencoder classifies cyber anomalies and visualizes the classified data. By learning the pattern of normal data, the performance of classifying abnormal data with 92.4% accuracy was derived, and the auxiliary index also showed 90% performance, ensuring reliability of the results. In addition, it is expected to be able to effectively defend against cyber attacks because it is possible to effectively recognize the situation by visualizing the congested cyber space.