• Journal of the Korean Society of Marine Environment & Safety
• /
• v.14 no.3
• /
• pp.235-240
• /
• 2008

In case of EU and USA, a short sea shipping and coastal shipping which are safer and environmentally better than road transportation are used widely. But a share of freight transport by a coastal transportation is extremely poor in South Korea. In this paper, we propose a Mokpo-Jeju intermodal transportation based on logistics analysis results. Firstly, we investigate a freight and passenger of a Mokpo-Jeju shipping route. And secondly, the intermodal transportations such as sea-train, sea-road, RORO ship system are investigated. Finally, we propose a coastal transportation system utilizing RORO ship system for Mokpo-Jeju shipping route and identify a technical feasibility of a coastal transportation system.

• Journal of Korean Society of Transportation
• /
• v.34 no.1
• /
• pp.81-94
• /
• 2016

The Korean real-time traffic responsive control systems, Cycle Offset Split Model of Seoul (COSMOS), employs a single theoretical model to estimate the degree-of-saturation (DS) on approaches. However, the deployment of the system has been accomplished without practical consideration of its field performance. This paper delivers a diagnosis study performed to find the relationships yet known on the DS values against the operational conditions unproved in theory but ordinarily observed in field practice. Based on the analysis of the historical log data (476,505 cycles) obtained from the COSMOS server, it was found; (1) full coverage of lane detections should perform better than the sample coverage of detection in ordinary conditions, (2) the sample coverage of detection perform better than the other case with an exclusive bus lane, (3) detection in which a shared lane is involved provide poor estimation of DS, (4) poor DS estimation when a detection lane is adjacent to a shared lane, and (5) the DS values obtained during a day can hardly be stable all time. The findings suggest traffic engineers a progressive direction to move forward for the next real-time traffic control systems.

• Journal of the Korean Electrochemical Society
• /
• v.22 no.4
• /
• pp.172-176
• /
• 2019

The first commercialized cathode material, $LiCoO_2$, suffers from disadvantages such as high cost and toxicity and also possesses safety problems. The nickel-rich $LiNi_{0.9}Mn_{0.1}O_2$ cathode material, used as an alternative to $LiCoO_2$, has highly reversible capacity and high energy density. So, the nickel-rich $LiNi_{0.9}Mn_{0.1}O_2$ cathode material is widely used as an alternative to $LiCoO_2$ due to its highly reversible capacity and high energy density. However, $LiNi_{0.9}Mn_{0.1}O_2$ has several disadvantages as well, such as poor cycle performance and poor thermal instability. To address these problems, we synthesized a new material, $LiNi_{0.5}Mn_{0.5}O_2$, as a shell on the surface of a core to suppress the surface degradation. The new material showed high structural and thermal stabilities and could also maintain a high capacity. The capacity retention of the core-shell cathode (87.7%) was better than that of the core cathode (76.9%) after 50 cycles. Analysis using differential scanning calorimetry revealed that the heat generation in the core-shell cathode ($65.9Jg^{-1}$) was lower than that in the core cathode ($559.7Jg^{-1}$).

• Journal of Korea Planning Association
• /
• v.54 no.4
• /
• pp.71-78
• /
• 2019

Due to the rapid pace of low fertility and aging of Korea, population decline is rapidly progressing in the outskirts of the province and county. Demand for public transport is decreasing due to suburban population declines, while local government funding for maintenance of the bus system is expected to increase gradually. The government and municipalities are promoting the introduction of Demand Responsive Transport (DRT) in order to reduce the burden of financial support for buses while enhancing mobility of the residents in vulnerable areas. However, most DRTs in Korea have been operated mainly in the areas that are not provided with public transportation services. Although DRT is able to reduce the financial burden of local governments, it is not easy to be introduced because of the objection of the existing bus users. In this study, 11 out of 61 towns with poor public transportation services in Gyeongsangnam-Do were selected for the introduction of DRT to replace bus services by using village characteristics. The results of this study are expected to be used as a basis for decision making to use DRT instead of bus service for the burden of bus financing for local governments.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.5
• /
• pp.1671-1686
• /
• 2022

Face manipulation tools represented by Deepfake have threatened the security of people's biological identity information. Particularly, manipulation tools with deep learning technology have brought great challenges to Deepfake detection. There are many solutions for Deepfake detection based on traditional machine learning and advanced deep learning. However, those solutions of detectors almost have problems of poor performance when evaluated on different quality datasets. In this paper, for the sake of making high-quality Deepfake datasets, we provide a preprocessing method based on the image pixel matrix feature to eliminate similar images and the residual channel attention network (RCAN) to resize the scale of images. Significantly, we also describe a Deepfake detector named Cascaded-Hop which is based on the PixelHop++ system and the successive subspace learning (SSL) model. By feeding the preprocessed datasets, Cascaded-Hop achieves a good classification result on different manipulation types and multiple quality datasets. According to the experiment on FaceForensics++ and Celeb-DF, the AUC (area under curve) results of our proposed methods are comparable to the state-of-the-art models.

• Journal of Korea Port Economic Association
• /
• v.26 no.4
• /
• pp.101-121
• /
• 2010

Domestic trucking transportation market does not have only the poor business environment but also the serious defects on the transportation trading structure. It makes weaken the competitiveness of trucking industry and hinders the development of trucking industry. The problems of trucking industry such as the recession of the Korean economy and decrease of the trucking charge cause the truck drivers suffer. Korean government and national assembly try to change the law of truck transportation business. The suggested law includes the obligation of trucking information networking system and it can make the transportation business structures more efficiently. This article deals with the strategies for the establishment of trucking transportation networking system and examines the cost-benefit analysis assuming the four demand senario. The results suggest the establishment of the information system not based on the individual trucking industry but on the joint industry at the level of the local area. This article also suggests that the information system has a positive financial feasibility.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.4
• /
• pp.907-920
• /
• 2015

By increase owning vehicle, infrastructure that accept vehicle is very poor on present that People's commuting is rapidly change to vehicle-use-form in metropolitan area. Although Transportation demand management is enforced, traffic is heavy but studies lake in internal and external. This study select Transportation demand management that enforce in internal and external and do a survey. Based on this survey, conduct AHP (Analytic Hierarchy Process) analvsis, Transportation demand management that enforce internal and external compare, decide superiority and understand every particular items' importance and satisfaction that users think. Also based on importance that collect by AHP analysis compare Transportation demand management character. Finally figure that grasped by this study, analysis present, found future TDM course and applicate future transportation improvement.

• Journal of the Korean Institute of Navigation
• /
• v.24 no.5
• /
• pp.397-403
• /
• 2000

Since very large and high-speed ships have been appeared in marine transportation from 1970s, these ships with poor maneuverability have made large-scale accidents frequently all over the world. The IMO(International Maritime Organization) recommended that ship designers should evaluate various maneuvering performance at initial stage and serve them to ship operators when they deliver a new ship. Meantime, it is expected that ships with large and wide superstructure would have poor maneuverability when they are affected by strong wind. Therefore, car carrier ship with large superstructure was selected to confirm how the ship responds to the external wind forces in this paper. The lateral and transverse projected areas above the water level were considered and ship behaviors were checked by change of rudder angles under severe wind conditions of different directions. In addition, hydrodynamic derivatives and coefficients were predicted from ship particulars and numerical calculations were carried out with the mathematical model of low speed maneuvering motions.

• 도로교통
• /
• s.84
• /
• pp.23-39
• /
• 2001

Increasing constructions of tunnels are become larger of the size and longer of the length. Construction of the tunnellinings is in poor working environment, for example, dark and narrow underground. Therefore, it is difficult to constructlining by required quality in these poor working conditions. In case of the designing tunnel in large scale, particularly, there may be several problems as follows; delay of construction due to a long time in constructing lining and difficulty of quality control. It is also indicated that longitudinal cracks of them are main defects in domestic tunnels. Therefore, in this study, the precast lining method is introduced for solving problems, which are delay of the tunnel construction a d deterioration of tunnel lining. Precast linings have mainly been constructed in Norway and North Europe. A new construction method of tunnel lining, suitable in domestic situation, is introduced by detailed case study. Also, useful materials for design and construction of Precast lining are presented.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.2217-2224
• /
• 2011

The railway industry has well developed with Korea's economic growth as follows - Industrial railway's electrification in 1973, Seoul subway opening in 1974, Busan subway opening in 1985, High speed railway opening in 2004. But LRT as city transportation means has been faced with many difficulties. Looking at the LRT projects implemented until now, there are some issues like the transportation demand, the quality & safety of RS and facilities, the poor management of inhabitant complaints and the failure to maintain policy coherence. They have caused not only the project schedule to extend but also the project costs to increase, even to obstruct the project progress itself in some cases. These risk factors become the obstacle of LRT project's success, but it is said that more basic problem is the lack of risk management capability of competent authorities in railway business. Under these circumstance, Railway specialized Authorities and Local government have cooperated to identify various risk factors and to prepare the measures in advance, so we try to introduce this cooperation case, which will help other local government as an useful reference.