• Journal of Navigation and Port Research
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• v.48 no.3
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• pp.171-180
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• 2024

Recently, there has been a global emphasis on decarbonization in order to address climate change and achieve carbon neutrality by 2050. In line with government regulations, domestic port authorities have also started participating in this global agenda. Since 2010, when decarbonization became an important task in ports, there have been studies analyzing the environmental efficiency of container terminals, taking into account undesirable outputs. However, most of these previous studies only measured carbon dioxide emissions based on Tier 1, whereas this study is the first to analyze the environmental efficiency of South Korea's container terminals based on Tier 3, as presented in the IPCC guidelines. The study considered 17 container terminal operators in South Korea as decision-making units and used the DEA-SBM Model. Subsequently, an Undesirable Outputs Model was conducted to calculate the environmental efficiency.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.10
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• pp.701-708
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• 2011

In this study, the emissions of GHG from general ships were calculated by Tier1 method based on the fuel consumption, and by Tier3 method based on the activities data such as power and SFOC of each engine, sailing characteristics (e.g. time and load factor, etc.) considering the ship type. In 2009, the emissions of GHG by Tier1 and Tier3 method were appeared 28.27 mega-ton $CO_{2eq}$ and 30.81 mega-ton $CO_{2eq}$. The emissions by Tier3 were slightly more than those by Tier1. We found that the values of the sailing characteristics for surveyed data are overestimated slightly. In the near future, more detailed researches for sailing characteristics considering ship types would be needed for sailing, anchoring, and berthing condition, etc.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.68-69
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• 2023

Recently, decarbonization has been emphasized worldwide to cope with climate change, and carbon neutrality by 2050 has emerged as a global agenda. The domestic port authorities have been participating in the global agenda in line with the government regulations. Since 2010, when decarbonization has been regarded as an important assignment in ports, container terminal efficiency considering undesirable outputs such as Carbon dioxide has been analyzed. However, most previous studies measured carbon dioxide emissions according to the Tier 1 and it is a first time to analyze container terminal efficiency based on the Tier 3 presented in the IPCC guidelines. 17 domestic container terminal operators were considered as decision making units and DEA-SBM Model was used. Subsequently, Undesirable outputs model was conducted to calculate the environmental efficiency.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.9-21
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• 2013

Tracking is a process which explores user equipment (UE) in the area of tracking in terms of cells. In this paper, two tracking schemes based on macrocell-microcell tiers in hierarchical LTE networks, PMMT and IMMT, are evaluated. In this network, UE can receive a signal from macrocells and overlapping microcells, and can be called from each macrocell or microcell-tier in the PMMT. Also, the UE can be called from the combined macrocell-tier and microcell-tier in the IMMT. Finally, we analyze the optimization of load balance between marcocell-tier and microcell-tier, and an analytical model is developed to evaluate those two arrangements.

• Journal of Digital Convergence
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• v.14 no.8
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• pp.211-221
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• 2016

The rapid trends toward outsourcing and collaboration have created complex multi-tier supply chains for construction and engineering industries. Working with suppliers and sub-suppliers requires continuous integration activities in order to maximize the performances of the entire supply chain. The purpose of this study is to identify the factors influencing the performances and long-term business relationship of second-tier suppliers in directed sourcing environment. This study proposes the asset specificity, trust, information-sharing and collaboration, as antecedents variables, and collected the survey responses from the second-tier suppliers in rebar manufacturing works. The statistical results indicate that the asset specificity, trust, information-sharing and collaboration have significant influences on the long-term business relationship of rebar manufacturing second-tier suppliers, but trust has no impact on the performances of second-tier suppliers at 5% significance level. Practical implications are also discussed.

• International Commerce and Information Review
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• v.16 no.4
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• pp.55-75
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• 2014

Non-parametric method such as technology efficiency, DEA/Window model and Malmquist Productivity Index (MPI) are used to measure efficiency and productivity of ICT (Information and Communication Technology) manufacturing industry and service industry over the period 2007-2011. The results of this paper indicate following: (1) Technology efficiency of the ICT manufacturing industry were found as the range of 0.34 and 0.39 over the sample period. Technology efficiency of the ICT service industry were found as the range of 0.16 and 0.20 over the sample period. (2) The geometric average of the Malmquist TFP indexes on ICT manufacturing industry indicated the productivity improvement an average of 8.3 percent. The geometric average of the Malmquist TFP indexes on ICT service industry indicated the productivity improvement an average of 1.6 percent. (3) TIER analysis result on ICT manufacturing industry showed that optimal bench marking made by storage devices${\rightarrow}$wireless communication equipment${\rightarrow}$broadcasting equipment${\rightarrow}$radio, recording and playback devices${\rightarrow}$computers, printers, video and audio-visual equipment path. TIER analysis result on ICT service industry indicated that optimal bench marking made by computers and packaged software${\rightarrow}$wired communication${\rightarrow}$communication, information, detection equipment${\rightarrow}$consulting and construction for computer systems integration${\rightarrow}$industrial machinery and equipment rental${\rightarrow}$telecommunications reseller${\rightarrow}$system software development and delivery${\rightarrow}$hosting path.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.93-103
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• 2014

The rapid trends toward outsourcing have created more complex and fragmented multi-tier supply chains for Engineering, Procurement & Construction(EPC) industry. Working with suppliers and sub-suppliers requires continuous integration activities during project execution. The purpose of this study is to identify the factors influencing the performances and relationship satisfaction of second-tier suppliers participating in the project-based supply chain. This study proposes the network embeddedness, collaboration, information-sharing and flexibility as antecedents variables, and collected the survey responses from the second-tier suppliers having experiences with complex projects. The statistical results indicate that the collaboration with supply chain leading firm and first-tier supplier has significant impact on the performances and relationship satisfaction of second-tier suppliers. It was also found that the information-sharing and flexibility influence the network embeddedness as well as collaboration, and that the embeddedness have significant impact on the collaboration.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.590-597
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• 2013

For a lower tier defense, the distance between a launcher and an engagement control station is quite important to estimate the proper defense area and to effectively arrange missile launchers. In this paper, we have analyzed an effectiveness of anti-ballistic missile launcher arrangement for the lower tier defense against the ballistic missile. The operation concept, specific configuration and aerodynamic characteristics of the ballistic missile such as SCUD-B/C, Nodong are considered in order to develop a realistic engagement simulation. The diverse engagement results through numerical simulations are provided to conduct the effectiveness analysis of anti-ballistic missiles.

• Journal of Digital Convergence
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• v.11 no.5
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• pp.307-312
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• 2013

This paper aims to design and realize movie reservation system with EJB 3.1 lightweight container architecture. N-Tier enterprise architecture to resolve the problem with benefits to support the new architecture is a lightweight container architecture. This architecture, such as the EJB, but not heavy, to provide all of the architecture is possible. The lightweight container architecture is most often used in business EJB 3.1 is well-known architecture. Therefore, this research has the N-tier enterprise architecture to solve the advantages and disadvantages developed to support the latest EJB 3.1 architecture based on the design and implementation of a movie reservation system.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.209-213
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• 2013

This paper aims to design and realize mobile webapp ticket reservation system based smartphone with N-tier mobile webapp framework. In mobile framework, presentation-tier utilizes HTML5/CSS3 and Sencha Touch, middle-tier consists of spring framework and MyBatis, database-tier using oracle possible to apply enterprise services mobile webbapp offices. In this study, mobile framework deploy and configuration management without the support of the app in N-tier that does not need to be considered in the smartphone-based mobile webapp ticket reservation system analysis and design, and then implementation.