• Journal of Digital Convergence
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• v.18 no.12
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• pp.195-204
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• 2020

The purpose of this study is to look for the relationship between export weight and control volume, inland cargo, export cargo transport, ship departure. The analysis period were used for a total of 113 monthly data from January 2011 to May 2020. Data were retrieved from the Korean Statistical Information Service of the Statistics Korea. The data used in this study were performed numerical analysis, index analysis and model analysis using the rate of change from the same month of the previous year. In the trend of the increase rate, the amount of control has plummeted from 150% to 60% due to the influence of Corona 19 in the beginning of 2020. At the same time, export weight and export cargo transport also decreased. As a result of the analysis, export weight showed relatively high synchronization with export cargo transport and control volume. On the other hand, export weight and inland cargo showed relatively low synchronization. Export weight is expected to continue in 2020 after the fluctuation rate began to decrease after 2019. If we can find the point of rebound in control volume or export cargo transport in the future, we can predict the point of increase in export weight. We expect to see an increase in export weight as soon as possible.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.24-31
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• 2011

This study deals with the operational effectiveness of roundabout. The roundabout is currently under consideration in our country depending on the result of existing researches, that the roundabout decreases delay and is environmentally friendly compared to the signalized intersection. The purpose of the study is to analyze the operational effectiveness of the roundabout by the change of pedestrian traffic volume. In pursing the above, this study gave particular emphasis to designing a network of roundabout, developing some scenarios for analysis including both entering traffic volume and pedestrians volume, and comparatively analyzing the average controlled delay time per vehicle. In this study, VISSIM model was used as a tool for traffic simulation. The main results are as follows. First, as a result of analyzing a traffic delay based on the pedestrian traffic volume, pedestrian traffic volume was analyzed to have a great impact on the roundabout operation. Second, the more pedestrian traffic volume were evaluated to indicate the more traffic delay. When the entering volumes with 1,000persons/hour (pedestrian volume) were more than 800pcph in the single-lane and 1,600pcph in the double-lane roundabout, the operational efficiencies of signalized intersections were evaluated to be better than those of roundabouts.

• Ocean and Polar Research
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• v.24 no.1
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• pp.1-18
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• 2002

Seasonal variation in global transport calculated from an ocean general circulation model (OGCM) has been assessed through the comparison with observational estimates. The OGCM based on the GFDL MOM1.1 has honzontal grid interval of 10 and 21 verticle levels, and was integrated for 31 years forced by climatological wind stress, freshwater flux, and heat flux with restoring. General features of the world ocean circulation are well reproduced, which include the western boundary currents such as the Kuroshio and the Agulhas Current, the Equatorial Current system, the Antarctic Circumpolar Current, and the Weddell Sea gyres. Also well resolved is the remarkable seasonal variation in the depth-integrated flows in the northern Indian Ocean due to the monsoonal wind. Monthly variation is found to be dominant in the transport of the Antarctic Circumpolar Current through the Drake Passage in accordance with observational estimates. It has been shown that the mid-latitude depth-integrated flows obey the Sverdrup relation, except for some regions such as continental shelf regions where the interaction between stratification and bottom topography is critical.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.839-842
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• 2012

We report for the first time the synthesis of niobium dioxide nanowires on a sapphire substrate by chemical vapor transport method. We identified single crystalline nature of as-synthesized nanowires by scanning electron microscopy and transmission electron microscopy. Niobium dioxide nanowires with their large surface-to-volume ratio and high activities can be employed for electrochemical catalysts and immunosensors. The Raman spectrum of niobium dioxide nanowires also confirmed their identity.

• Computers and Concrete
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• v.31 no.6
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• pp.485-499
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• 2023

Both damage and unsaturated conditions accelerate the transport of erosive media inside concrete. However, their combined effects have not been fully investigated. A multiscale mortar model using representative volume elements is developed, capturing the number and distribution in each phase. Afterwards, mortar damage microstructure evolution is simulated in the tensile process. Finally, the unsaturated mortar transport is predicted and analysed. The results indicate that damage significantly affects the diffusion process in the early stage, while the transport performance is weakened due to the obstruction of the nontransport phase in the later stage. The higher the saturation and the more connected pores, the faster the diffusion rate of chloride ions. Chloride ions spread around the cracks in a tree-like manner along. The model can very well predict the chloride ion transport performance of unsaturated and damaged mortar.

• Proceedings of KOSOMES biannual meeting
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• 2008.05a
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• pp.61-67
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• 2008

This study analyzes the characteristics of material transportation between Busan new-port and Nakdong river estuary. Measurements of water temperate, salinity, turbidity, and tide is also analyzed to determine the characteristics of sea water and described the tidal current between two regions. For the purpose of indicating characteristics of tidal current numerical modeling is used. From the observed results, the total volume transport of sea water calculations revealed $184.71m^3/sec$ and residual volume transport was $(+)59.74m^3/sec$ during the 1st field measurement, and the total volume transport was $331.15m^3/sec$ and residual volume transport was $(-)28.88m^3/sec$ during the 2nd. The numerical simulation for three different topography cases are calculated. The results are summarized as follows: 1) The volume of material transportation about $0.7\sim18.4%$ is decreased as the depth of Busan new-port decrease (10 m). 2) The volume of material transportation about $3.5\sim21.9%$ is increased, as channel(water depth is 5 m) constructed to the Nakdong river estuary direction.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.5
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• pp.22-35
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• 2013

With the increase in image detectors, concerns about the reliability of traffic information are increasing. In this paper, we propose a method to generate reliable traffic volume using analysis of the point detector data as a representative value. Therefore, targeting expressway, we analyzed the difference in traffic volume collected by loop and image detector, and verified statistically using t-test, and finally analyzed the error rate compare to the real traffic volume. Analysis revealed that there was a statistically difference the traffic date collected by the loop detector and the image detector, in the same period, the same time, respectively. In addition, the difference between the actual traffic volume and traffic that have been collected in a loop detector was the lowest Therefore, creating a traffic volume of representative value, we proposed a method to use loop detector than the average traffic volume collected by each detector. It shows that it is more important to use one high-quality data rather than various low-quality data to produce a representative value.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1042-1043
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• 2005

• Journal of the Korean earth science society
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• v.26 no.7
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• pp.714-724
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• 2005

The East Sea, a semi-enclosed marginal sea with shallow straits in the northwest Pacific, is marked by the nearly geographic isolation and the low sea surface salinity during the last glacial maximum (LGM). The East Sea might have the only connection to the open ocean through the Korea Strait with a sill depth of 130 m, allowing the paleo-Tsushima Water to enter the sea during the LGM. The low paleosalinity associated with abnormally light $\delta^{18}O$ values of planktonic foraminifera is interpreted to have resulted from river discharge and precipitation. Nevertheless, two LGM features in the East Sea are disputable. This study attempts to estimate volume transport of the paleo-Tsushima Water via the Korea Strait and further examines its effect on the low sea surface salinity (SSS) during the lowest sea level of the LGM. The East Sea was not completely isolated, but partially linked to the northern East China Sea through the Korea Strait during the LGM. The volume transport of the paleo-Tsushima Water during the LGM is calculated approximately$(0.5\~2.1)\times10^{12}m^3/yr$ on the basis of the selected seismic reflection profiles along with bathymetry and current data. The annual influx of the paleo-Tsushima Water is low, compared to the 100 m-thick surface water volume $(about\;79.75\times10^{12}m^3)$ in the East Sea. The paleo-Tsushima Water influx might have changed the surface water properties within a geologically short time, potentially decreasing sea surface salinity. However, the effect of volume transport on the low sea surface salinity essentially depends on freshwater amounts within the paleo-Tsushima Water and excessive evaporation during the glacial lowstands of sea level. Even though the paleo-Tsushima Water is assumed to have been entirely freshwater at that time period, it would annually reduce only about 1‰ of salinity in the surface water of the East Sea. Thus, the paleo-Tsushima Water influx itself might not be large enough to significantly reduce the paleosalinity of about 100 m-thick surface layer during the LGM. This further suggests contribution of additional river discharges from nearby fluvial systems (e.g. the Amur River) to freshen the surface water.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.2
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• pp.1-13
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• 2015

Traffic volume data is basic information that is used in a wide variety of fields. Existing missing traffic volume data imputation method did not take the effect on the rainfall. This research analyzed considering of the rainfall effect in missing traffic volume data imputation method. In order to consider the effect of rainfall, established the following assumption. When missing of traffic volume data generated in rainy days it would be more accurate to use only the traffic volume data of the past rainy days. To confirm this assumption, compared for accuracy of imputed results at three kinds of imputation method(Unconditional Mean, Auto Regression, Expectation-Maximization Algorithm). The analysis results, the case on consideration of the rainfall effect was more low error occurred.