• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.48-61
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• 2020

The objective of this study is to estimate traffic capacity based on the heavy-vehicle ratio in a two-lane freeway work zone where one lane is blocked by construction. For this, closed circuit television (CCTV) video data of the freeway work zone was collected, and the congestion at an upstream point was observed. The traffic volume at a downstream point was analyzed after a bottleneck was created by the blockage due to the upstream congestion. A distribution model was estimated using observed-time headway, and the road capacity was analyzed using a goodness-of-fit test. Through this process, the general capacity and an equation for capacity based on the heavy-vehicle ratio passing through the work zone were presented. Capacity was estimated to be 1,181~1,422 passenger cars per hour per lane (pcphpl) at Yeongdong, and 1,475~1,589pcphpl at Jungbu Naeryuk. As the ratio of heavy vehicles increased, capacity gradually decreased. These findings can contribute to the proper capacity estimation and efficient traffic operation and management for two-lane freeway work zones that block one lane due to a work zone.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.668-673
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• 2003

Line Capacity is a criteria for transport capacity and is used to evaluate railroad investment alternatives or to decide train frequency when establish transportation plan. There are two methodologies to increase transport capacity of railway. One is to invest railroad equipment or vehicles, and the other is to improve operation efficiency through optimization. Such all efforts are intended to increase transport capacity by improving line capacity. So far, this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. In this paper, we present a new estimation method of line capacity based on the probability simulation, and apply to normal railline section and special structured railine section.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.147-156
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• 2006

Metropolitan Subway, tke volume of station, distance between station is short. when the demand is concentrated during moving peak periods, the Headway that than Line Headway in which Station Headway is applied to Station Capacity computation be. The factors to determine the Station Headway have a fixing Price of the machine and the Dwell time. Other factors aye decided already or fixing price but the Dwell time that change according to demand cause the biggest effect at Station Headway. After analyze constituents that influence to Station Headway in this study calculated correct Station Capacity drawing estimating dwell time model that change according to demand.

• Proceedings of the KOR-KST Conference
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• 1996.06a
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• pp.59-76
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• 1996

• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.179-184
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• 1999

• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.223-228
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• 1999

• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.397-402
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• 1999

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.05a
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• pp.92-93
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• 2018

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.357-364
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• 2014

Size controlled, $LiNi_{0.8}Co_{0.15}Al_{0.05}O_2$ cathode powders were prepared by co-precipitation method followed by heat treatment at temperatures between 750 and $850^{\circ}C$. The synthesized samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical performance. The synthesized $LiNi_{0.8}Co_{0.15}Al_{0.05}O_2$ after calcined at $750^{\circ}C$ has a good electrochemical performance with an initial discharge capacity of $190mAhg^{-1}$ and good capacity retention of 100% after 30 cycles at 0.1C ($17mAg^{-1}$). The capacity retention of $LiNi_{0.8}Co_{0.15}Al_{0.05}O_2$ after calcined at $750^{\circ}C$ is better than that at 800 and $850^{\circ}C$ without capacity loss at various high C rates. This is ascribed to the minimized cation disorder, a higher conductivity, and higher lithium ion diffusion coefficient ($D_{Li}$) observed in this material. In the differential scanning calorimetry DSC profile of the charged sample, the generation of heat by exothermic reaction was decreased by calcined at high temperature, and this decrease is especially at $850^{\circ}C$. This behavior implies that the high temperature calcinations of $LiNi_{0.8}Co_{0.15}Al_{0.05}O_2$ prevent phase transitions with the release of oxygen.

• Journal of the Korean Electrochemical Society
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• v.22 no.4
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• pp.172-176
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• 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 ($559.7Jg^{-1}$).