• Journal of Korean Society of Transportation
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• v.34 no.3
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• pp.263-277
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• 2016

Traffic safety in freeway work zones is of keen interest since both crash frequency and severity are much higher than those in general freeway sections. The lane closure in work zones results in greater work load of drivers due to compulsory lane changes and speed reduction. Therefore, traffic merging control is an effective countermeasure for enhancing work zone safety. This study proposed an integrated framework based on driving and traffic simulations to evaluate traffic merging control methods in terms of traffic safety. In addition to the conventional merging method using the taper, joint merge and chicane-type merge were evaluated by the proposed methodology. Chicane-type merge outperformed other methods under level of service (LOS) A and B. On the other hand, it was identified that joint merge showed the best safety performance under LOS C traffic conditions.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.90-98
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• 2017

This paper is concerned with air traffic controllers' fatigue and stress that they experience during their daily job particularly as being shift workers. Previous researches reveal that the controllers' fatigue and stress increase by several factors including time spent at work, traffic intensity, visibility, etc. The researches also indicate that air traffic controllers' fatigue and stress can be reasonably surrogated by their heart rate. We set three hypotheses relating the influencing factors and the fatigue and stress represented by the heart rates. Using wrist bands, air traffic controllers' heart rates at various situations are collected at Choongju airport. The hypothetical tests explicitly confirm that the heart rate is highly correlated with the traffic level and the time spent at work. In particular, it be shown that even when handling the same traffic level, air traffic controllers' stress level increases as the time they spent at work increases.

• Journal of Advanced Navigation Technology
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• v.22 no.1
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• pp.13-19
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• 2018

In this paper, we classified a flight pattern of unmanned aerial vehicle(UAV) which will be operating in UTM system and analyzed its flight pattern by purpose of use. Flight patterns of UAV are sorted into three patterns which are circling, monitoring and delivery. We considered four cases of industry areas using UAV which are agriculture, infrastructure monitoring, public safety & security(p.s.s) and delivery. It is necessary to build a simulation model as a verification tool for applying the flight pattern according to the use of UAV to the real UTM system. Therefore, we propose the simulation model of UAV with updating states over time. We applied simulation to UAV monitoring flight pattern, and confirmed that the flight was done by the given input data. The simulation model will be used in the future to verify that the UAV has various flight patterns and can operate safely and efficiently for the intended use.

• Journal of Navigation and Port Research
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• v.41 no.1
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• pp.17-24
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• 2017

This study uses Conjoint Analysis to study optimal port operations at the newly built International P assenger Terminal (IPT) at Inchon Port, Korea. The perceptions of users, operators, and the Incheon Port Authority are compared and analyzed. The results of user Conjoint Analysis showed that rent calculation method was the most important factor in the NIPT operation plan, followed by establishing automation and the size of the site area. For the Incheon Port Authority and operators, the rent calculation method turned out to be the most important factor for NIPT operation plans. It was followed by establishing automation and the site area. Utility results showed the "investment cost preservation method" to have the highest rent calculation utility, "yard automation" as the priority, and "43,000 pyeong-48,000 pyeong" as the optimal site area.

• The Journal of Society for e-Business Studies
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• v.11 no.1
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• pp.113-126
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• 2006

The scope of e-Commerce process becomes wider as the emphasis on the enterprise collaboration grows. It has expanded from its initial settings of order management or billing processes to cover various collaborative processes in the company's value-chain. In order for those collaborative e-Commerce processes to be successful, corresponding business processes should be fully supported by standard bodies. The RosettaNet consortium, one of the most representative international B2B standard bodies, has steadily provided new PIPs to support those expansions. Since individual RosettaNet PIPs correspond to unit tasks that are executed separately in or between companies, multiple PIPs have to be integrally used to properly handle larger business cases. RosettaNet implementation, however, has suffered from the lack of standard guidelines or deliverables to refer under this multi-PIP environment. In this research, a contents-based document routing system is implemented. By applying this routing system to the RosettaNet e-Logistics program where multi-PIP environment is inevitable, we verified our contents-based document routing system is effective to support multi-PIP environment flexibly.

• Journal of Korea Port Economic Association
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• v.29 no.2
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• pp.211-238
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• 2013

The Port Logistics Information System (Port-MIS) is the system that processes all of port management such as entry and departure of ships, using facilities within ports, port traffic control, cargo entering and carrying and tax collection in 31 trade ports over the whole country. Lately, The Port Logistics Information System (Port-MIS) has been reformed as a WEB-based system and established basis to provide real time information support structure, diversification of civil complaint system, and optimized civil complaint service by using wire and wireless internet. The typical study on the Port Logistics Information System was C/S program and EDI-centered. But it has significance to study on service quality measurement of WEB Port-MIS that has been served as a new web-based platform since April 2010, for there was no such a study until now.

• Journal of Digital Convergence
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• v.16 no.4
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• pp.49-54
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• 2018

Russia has access to unique port locations and routes, one of them is North Sea route, which have been a major debate topic for last several decades. In order to handle any shipments along the route, an adequate and capable port system must be present. This study aims to identify development and competition patterns from 2007 to 2016 of Russian ports in the Arctic basin, concentration trends in particular. The objectives achieved through utilizing the Herfindahl-Hirschman Index (HHI), concentration ratio (CR), the Gini coefficient and Lorenz curve, and shift-share analysis. Results demonstrate concentration trend, positive overall growth and lack of real competition. Originality of this study lies in the fact that certain analysis had not been done in previous studies, but importance of it may be found in several papers. Findings of this paper may assist policy-makers, port authorities and other researchers in understanding and further study on the region.

• Korean Journal of Construction Engineering and Management
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• v.12 no.5
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• pp.46-54
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• 2011

There have been research and developments for effective and efficient logistics and progress management in a construction project. Among them, RFID+4D has been developed for the supply chain management of long-lead item materials such as steel component, precast concrete component and curtain wall by integrating RFID with 4D CAD. And the feasibility of RFID+4D has been verified and validated and the benefits in terms of time and cost were shown in several case studies. However, the previous development of RFID+4D has not been adapted widely because of additional modeling cost, non-real time data update, additional labor for data update, and so forth. Therefore, this research has proposed a framework and process for solving these problems. And the web based simulation system has been developed and verified based on the proposed framework. The proposed framework and process can improve the existing RFID+4D system in a construction project by saving its operation cost and utilizing project information more efficiently and effectively. Also it is expected that the proposed framework could be applied to a method transferring design RIM data to construction BIM data.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.6
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• pp.781-787
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• 2010

Forecasting possible failure characteristics is very important in maintenance planning because it helps in predicting any future failures and determining the optimum replacement interval. This paper examines the time.to-failure distribution of the transfer gearbox of a J79 engine by using a probability plotting technique which is one of the most convenient techniques for reliability analysis. Various probability distributions are evaluated for determining the suitable probability distribution of the failure data of the transfer gearbox, and the resulting correlation coefficient indicates that failure data have a lognormal distribution. The expected number of unscheduled maintenance actions and the optimum replacement interval for various values of cost ratios are determined.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.278-291
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• 2017

Effective installation and operations of traffic safety signs in the advance warning area is of considerable interest for safer traffic management at freeway work zones. This study evaluated the feasibility of traffic safety sign installation based on a driving simulation experiment to take drivers' responsive characteristics into consideration. Both the compliance rate for speed limit and a lane-changing safety index were used for evaluating a set of driving simulation scenarios. It was identified that providing speed limit signs to reduce speed in advance and afterward guiding lane-changing could lead to safer maneuvering of vehicles entering work zones. The outcomes of this study are expected to be useful for revising freeway work zone management policies toward crash prevention.