• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.3-17
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• 2007

This paper provides an introduction to life-span simulation and numerical approach to support the performance design processes of reinforced concrete structures. An integrated computational system is proposed for life-span simulation of reinforced concrete. Conservation of moisture, carbon dioxide, oxygen, chloride, calcium and momentum is solved with hydration, carbonation, corrosion, ion dissolution. damage evolution and their thermodynamic/mechanical equilibrium. Coupled analysis of mass transport and damage mechanics associated with steel corrosion is presented for structural performance assessment of reinforced concrete. Multi-scale modeling of micro-pore formation and transport phenomena of moisture and ions are mutually linked for predicting the corrosion of reinforcement and volumetric changes. The interaction of crack propagation with corroded gel migration can also be simulated. Two finite element codes. multi-chemo physical simulation code (DuCOM) and nonlinear dynamic code of structural reinforced concrete (COM3) were combined together to form the integrated simulation system. This computational system was verified by the laboratory scale and large scale experiments of damaged reinforced concrete members under static loads, and has been applied to safety and serviceability assessment of existing structures. Based on the damage details predicted by the nonlinear finite element analytical system, the life-span-cost of RC structures including the original construction costs and the repairing costs for possible damage during the service life can be evaluated for design purpose.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.59-65
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• 2015

To build a flexible network than traditional transport network, the carrier ethernet technology is emerging in network industry recently and MPLS-TP technologies are being applied as a major standard technology for the carrier ethernet. However, network management technologies required to handle equipment installed in MPLS-TP network are not clear. This paper propose an efficient method to build a management network automatically without any additional configuration when network equipments are installed in MPLS-TP network. The proposed scheme reduce cost required for both equipment installation and network maintenance by minimizing configuration procedures of connecting management system with network. We evaluated the effectiveness of the proposed scheme by applying the scheme to a real MPLS-TP equipment.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.2075-2089
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• 2008

Improvement of transport system is necessary to advance the freight traffic meanwhile logistics are getting bigger and faster by worldwide tendency. The link between each transportations occurs bottleneck state and it raises the necessity of non-stop mixed transport system which can reduce the cost of logistics. DMT(Dual Mode Trailer) was designed to use road and railway at the same time for door to door service. It is called DMT for every transport system which can connect between road and railway in Korea. This study would like to examine the present condition of promotion for localization of DMT which is new idea and technology and suggest the new subjects from now.

• Advances in environmental research
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• v.11 no.1
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• pp.17-30
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• 2022

Road transport allows all forms of land conditions to be met at less cost. Because of this function, despite numerous disadvantages, it becomes the most frequently used method of transport, especially in underdeveloped or developing countries. One of the most significant factors used in evaluating the atmosphere's air quality is the amount of CO₂, increasing people's density in indoor spaces. The amount of CO₂ indoors is, therefore, vital to determine. In this study, CO₂ and temperature measurements made on nine different bus journey was made in Turkey. The minimum and maximum values were recorded as 555 ppm and 3000 ppm CO₂, respectively, in the measurements. On all journeys, the average concentration is 1088.72 ppm. The minimum and maximum values were measured as 17.4℃ and 32.7℃ in the temperature measurements, and the average of all trips was calculated to be 25.76℃. In this study conducted before the Covid-19 pandemic, it was determined that the amount of CO₂ increased with the density and insufficient ventilation in the buses. The risk of infection increases in places with high human density and low clean air. For situations such as pandemics, CO₂ measurement is a rapid indicator of determining human density.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.400.2-400.2
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• 2016

Dye-sensitized solar cells (DSSCs) have been widely investigated as a next generation solar cell because of their simple structure and low manufacturing cost. To realize a commercially competitive technology of DSSCs, it is imperative to employ a technique to prepare nanocrystlline thin film on the flexible organic substrate, aiming at increasing the flexibility and reducing the weight as well as the overall device thickness of DSSCs. The key operation of glass-to-plastic substrates conversion is to prepare mesoporous TiO2 thin film at low temperature with a high surface area for dye adsorption and a high degree of crystallinity for fast transport of electrons. However, the electron transport in the TiO2 film synthesized at low temperature is very poor. So, in this study, TiO2 films synthesized at high temperature were transferred on the selective substrate. We fabricated DSSCs at low temperature using this method. So, we confirmed that the performance of DSSCs using TiO2 films synthesized at high temperature was improved.

• Journal of Information Processing Systems
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• v.14 no.2
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• pp.487-498
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• 2018

The purpose of the high-speed railway construction is to better satisfy passenger travel demands. Accordingly, the design of the train working plan must also take a full account of the interests of passengers. Aiming at problems, such as the complex transport organization and different speed trains coexisting, combined with the existing research on the train working plan optimization model, the multiobjective bi-level programming model of the high-speed railway passenger train working plan was established. This model considers the interests of passengers as the center and also takes into account the interests of railway transport enterprises. Specifically, passenger travel cost and travel time minimizations are both considered as the objectives of upper-level programming, whereas railway enterprise profit maximization is regarded as the objective of the lower-level programming. The model solution algorithm based on genetic algorithm was proposed. Through an example analysis, the feasibility and rationality of the model and algorithm were proved.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.83-89
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• 2001

This paper provides a short description of the COMPASS-model which is a concept for the simulation of multiway systems. The focus of the COMPASS-model is to offer an opportunity to investigate the effects of redistribution strategies on logistic and monetary values in a system of returnable transport items (RTI). The modeling concept consists of five modules: topology, system load, distribution, redistribution, cost. It includes the integration of highly sophisticated evolutionary algorithms for the optimal solving of complex capacitated vehicle routing problems (CVRP) which are typical for RTI-systems. The results of first experiments with a COMPASS-based prototype are repeated. They reveal some basic regularities in RTI-systems.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10a
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• pp.51-58
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• 1998

This study is to define the Automated Container Terminal(ACT) and container terminal system. Also, we analyze the present condition of the container terminal system in Pusan port and its automation level by systems approach. And this paper aims at evaluating on the priority of R&D investment until the beginning of the second stage of New Pusan Port Project(2006). In this process we have considered 8 factors (cost, labor, area, time volume, reliability, safety, convenience) to analyze 6 subsystems. The priority order of R&D until target year by sub-systems is as follow : Cargo Handling System〉Transfer System〉Port Entry System〉Storage System(Distribution&Manufacturing System included)〉Inland Transport System〉Port Information System.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.2
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• pp.100-107
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• 2009

Velocity estimation is one of important issues for efficient system management in mobile cellular systems. In this paper, a modified velocity estimation scheme which works in Adaptive Antenna System (AAS) is proposed. The proposed scheme estimates user velocity based on moving distance information and sojourn time information. From numerical results, it is shown that the proposed scheme can estimate user velocity accurately with low cost.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.766-771
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• 2006

Railway stations are important facilities for transport of passengers and freights. The location of station have an effect on the efficiency of railway transport and operation. In this study, an inspection of the primary factors for station spacing in urban railway has been performed and a review for the propriety of the present states and further improvement has been carried. It may be helpful for proper decisions on the route planning in urban railway. Primary factors for station spacing are 1)train capacity, 2)competitiveness with other transportation, 3)accessibility and 4)construction cost, which is out of consideration in the inspection. From the result of this study, the proper station spacing is about 600m for the accessibility, more over 1.03km for the train capacity and more over 1.4km for the competitiveness with other transportation.