• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.124-140
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• 2017

There exists a limitation to provide proper advance information for safe maneuvering through guidance and caution signs in freeway mobile work zones, unlike fixed work zones. Although a work-protection vehicle is currently deployed at the rear of the work vehicle, more active countermeasures to prevent crashes are required. The purpose of this study was to propose a method to evaluate the safety in mobile work zones and to present effective countermeasures. Driving simulation experiments were conducted to analyze characteristics of driver's behavior in mobile and fixed work zones. Safety distance index (SDI) based on the comparison of stopping distances of a work-protection vehicle and a following subject vehicle was used to evaluate traffic safety. More dangerous driving behavior was observed in the mobile work zone. Especially, it was identified that the lane-change of vehicles following the work- protection vehicle was late. Therefore, it is necessary to actively introduce methods to provide warning information so that the driver can recognize the work-protection vehicle in advance and carry out appropriate evasive maneuvers.

• Journal of Navigation and Port Research
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• v.44 no.3
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• pp.211-218
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• 2020

In recent years, the hub and spoke strategy has been strengthened in accordance with the enlargement of ships. As the needs of the port users change, the ports are also becoming larger and modernized. Under these circumstances, changes in existing port operations are expected. One example is the movement to promote economic and operational effectiveness through the joint operation of small and medium-sized operators. This study analyzed the effect of the association of small and medium-sized operators on Busan New Port in terms of economy. Additionally, the issue of cost allocation within the association of operators was presented through the game theory. As a result, in the case of operating jointly rather than divided into five operating companies as of the present, it has been shown to have a cost reduction effect in terms of operating companies. Considering the use of the Proportional method, the Shapley Value, and the Nucleus method in allocating the costs among the operators participating in the coalition, the Shapley Value method was the most suitable method in this study.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.286-294
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• 2021

The International Maritime Organization (IMO) has been seeking measures to prevent climate change caused by shipping and actively discussing the initial strategy of reducing ship greenhouse gas emissions adopted in 2018. Member states are proposing various reduction measures in the IMO's 5th International Working Group on the Reduction of Greenhouse-gas emissions. However, each member country's method of measuring impact assessment differs, making it impossible to objectively compare impact assessment by country. As such, various measures have been proposed by each country to reduce greenhouse gas emissions, and it is necessary to determine a standard impact assessment measurement method that can be applied to all countries before 2023, when IMO's greenhouse gas reduction strategy is implemented. Therefore, this study seeks to develop detailed guidelines for impact assessment to objectively compare the impact assessment results of ships' greenhouse gas reduction measures. Drawing detailed guidelines that can compare the effectiveness of each country's reduction strategies will enable the IMO leading marine environment GHG reduction.

• Journal of Convergence for Information Technology
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• v.9 no.9
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• pp.133-140
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• 2019

Following the recent US trade deficit, the trade war began between Korea and Japan in July. Korea's trade dependence is about 60% or more, indicating high export dependence and import dependence. The purpose of this study is to examine export amount, export volume, export price index, Treasury bond interest rate and analyze how index affects export amount. This study attempts to analyze the comovement and volatility with export amount. For this purpose, monthly data for each indicator were selected for a total of 234 months from January 2000 to June 2019. As a result of analysis, exports amount and exports volume showed very high comovement, exports amount and interest rates showed low comovement, but exports amount and exports prices showed very low comovement. In the future, Korea should continue to increase exports amount in view of its high dependence on trade, along with policies to expand the domestic market. To this end, strategy to increase exports volume should be presented. Korea should increase the logistics environment and competitiveness of each port and airport, improve domestic and overseas network construction and support services of logistics companies.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1140-1147
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• 2022

With the development of digital technology, the marine environment is expected to change rapidly. In the case of autonomous vessels, technology is being developed in many countries, and the international community has begun to discuss ways to operate it. Changes in ships cause changes in the marine traffic environment and urge changes to aids to navigation. This study aims to analyze the cyber security management awareness of VTS personnel to improve the cyber security system for aids to navigation. To this end, the current status of cyber security management was reviewed with a focus on VTS, and a survey was conducted on VTS personnel. The survey analysis used the IPA methodology, and as a result of the analysis, a clear difference was observed in the perception of cybersecurity between those with experience in security and those without experience. In addition, technical measures related to cyber-attack detection and blocking should be implemented with the highest priority. The results of this study can be used as basic data for improving the cyber security management system for aids to navigation.

• The Journal of Bigdata
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• v.8 no.1
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• pp.131-156
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• 2023

The traditional retail industry significantly changed over the past decade due to the mobile and online technologies. This change has been accompanied by a shift in consumer behavior regarding purchasing patterns. Despite the rise of online shopping, there are still specific categories of products, such as "Processed food" in Mongolia, for which traditional shopping remains the preferred purchase method. To prepare for the inevitable future of retail businesses, firms need to closely analyze the performance of their offline stores to plan their further actions in a new multi-channel environment. Retailers must integrate diverse channels into their operations to stay relevant and adjust to the shifting market. In this research, we have analyzed the performance data such as sales, profit, and amount of sales of offline stores by using clustering approach. From the clustering, we have found the several distinct insights by comparing the circumstances and performance of retail stores. For the certain retail stores, we have proposed three different strategies: a fulfillment hub store between online and offline channels, an experience store to elongate customers' time on the premises, and a merge between two non-related channels that could complement each other to increase traffic based on the store characteristics. With the proposed strategies, it may enhance the user experience and profit at the same time.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.195-202
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• 2021

The purpose of this study is to classify national ships into passenger ships, cargo ships, oil tankers, tugboats, barges, and other ships by use, and compare the rate of change and direction respectively. In this study, a total of 123 monthly data were searched from January 2011 to March 2021 in Statistics Korea's KOSIS "Traffic Logistics => Operating Vessel Statistics => Possesion State of National Vessels". To this end, we calculated the rate of change from the previous month for each ship and performed numerical analysis and model analysis. In the correlation analysis, the Total showed a high relationship in the order of Towing, Barge, Oil, Cargo and Ferry. In the regression analysis, each ship was found to be statistically significant and varied independently of each other. The increase rate was highest in the order of Ferry, Oil, Towing, Barge and Cargo during the last analysis period. In the analysis of Scatter Charts, Towing and Barge showed more than a certain level of synchronization with respect to the Total. The synchronization phenomenon for each ships was calculated to be rather low, indicating that the correlation between each ships was low. However, the correlation between Oil and Towing, Oil and Barge and Towing and Barge is relatively high, indicating a relatively large correlation.

• The Korean Journal of Air & Space Law and Policy
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• v.34 no.1
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• pp.159-201
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• 2019

Along with Annex 14 Volume I establishment in 1951 and the set-up of restriction surface around the runway, aeronautical technique and navigation performance achieved dazzling growth, and the safety and precision of navigation greatly improved. However, restrictions on surrounding obstacles are still valid for safe operation of an aircraft. Standards and criteria for securing safety of aircraft operating around and on airport is stated in Annex 11 Air Traffic Services and Annex 14 Aerodrome etc. In particular, Annex 14 Volume I presents the criteria for limiting obstacles around an airport, such as natural obstacles such as trees, mountains and hills to prevent collisions between aircraft and ground obstacles, and artificial obstacles such as buildings and structures. On the other hand, Annex 14 Volume I, in the application of the obstacles limitation surfaces, apply the exception criteria, as it may not be possible to remove obstacles that violate the criteria if the aeronautical study determines that they do not impair the safety and regularity of aircraft operation. Aeronautical study has been applied and implemented in various countries including United States, Canada and Europe etc. accordingly, Korea established and amended some provisions of the Enforcement rules of the Aviation Act and established the Aeronautical study guidelines to approve exceptions. However, because ICAO does not provide specific guidelines on procedures and methods of Aeronautical study, countries conducting aeronautical study have established and applied their own procedures and methods. Reflecting this realistic situation, at the 12th World Navigation Conference and at the 38th General Assembly, the contracting States demanded a reexamination of the criteria for current obstacle limitation surfaces and methods of aeronautical study, and the ICAO dedicated a team of experts to prepare new standard. This study, in line with the movement of international change in obstacle limitation surface and aeronautical study, aims to compare and analyze current domestic and external standards on obstacle limitation and height limits, while looking at methods, procedure and systems for aeronautical study. In addition, expecting that aeronautical study will be used realistically and universally in assessing the impact of obstacles, we would recommend the institutional improvement of the aeronautical study along with the development of quantitative analysis methods using the navigation data in the current aeronautical study.

• Spatial Information Research
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• v.20 no.4
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• pp.29-36
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• 2012

The low-carbon freight transportation system was introduced due to increase traffic congestion cost and carbon-dioxide for global climate change according to expanding city logistics demands. It is necessary to create 3D-based road network map for representing realistic road geometry with consideration of fuel consumption and carbon emissions. This study propose that 3D road network model expressed to realistic topography and road structure within trunk road for intercity freight through overlaying 2D-based transport-related thematic map and 1m-resolution DEM. The 3D-based road network map for the experimental road sections(Pyeongtaek harbor-Uiwang IC) was verified by GPS/INS survey and fuel consumption simulation. The results corresponded to effectively reflect realistic road geometry (RMSE=0.87m) except some complex structure such as overpass, and also actual fuel consumption. We expect that Green-based freight route planning and navigation system reflected on 3D geometry of complex road structure will be developed for effectively resolving energy and environmental problems.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.185-193
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• 2011

As a Lift axle is an additional axle installed mostly in heavy freight truck, It"s introduced for the purpose of cost saving, such as logistics, fuel, tire wear and prevention of the pavement damage. However, the Effects of a lift axle are anecdotal and they have occurred often that a lift axle is used improperly by expectations of some drivers. For these reasons, this study conducts a field experiment in order to identifying the change rate of fuel consumption due to an a Lift axle using, develops the fuel consumption model of field data, and then compares the effects of a Lift axle using through application of the model. As a result, fuel consumption decreased in loading conditions that are both empty and full when not using a lift axle.